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Курнат Андрей
2026-06-07 10:20:04 +03:00
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# Compiled Object files, Static and Dynamic libs (Shared Objects)
*.o
*.a
*.so
# Folders
_obj
_test
# Architecture specific extensions/prefixes
*.[568vq]
[568vq].out
*.cgo1.go
*.cgo2.c
_cgo_defun.c
_cgo_gotypes.go
_cgo_export.*
_testmain.go
*.exe
*.test
*.prof
/s2/cmd/_s2sx/sfx-exe
# Linux perf files
perf.data
perf.data.old
# gdb history
.gdb_history
Server/vendor/github.com/klauspost/compress/.goreleaser.yml
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version: 2
before:
hooks:
- ./gen.sh
builds:
-
id: "s2c"
binary: s2c
main: ./s2/cmd/s2c/main.go
flags:
- -trimpath
env:
- CGO_ENABLED=0
goos:
- aix
- linux
- freebsd
- netbsd
- windows
- darwin
goarch:
- 386
- amd64
- arm
- arm64
- ppc64
- ppc64le
- mips64
- mips64le
goarm:
- 7
ignore:
- goos: windows
goarch: arm
-
id: "s2d"
binary: s2d
main: ./s2/cmd/s2d/main.go
flags:
- -trimpath
env:
- CGO_ENABLED=0
goos:
- aix
- linux
- freebsd
- netbsd
- windows
- darwin
goarch:
- 386
- amd64
- arm
- arm64
- ppc64
- ppc64le
- mips64
- mips64le
goarm:
- 7
ignore:
- goos: windows
goarch: arm
-
id: "s2sx"
binary: s2sx
main: ./s2/cmd/_s2sx/main.go
flags:
- -modfile=s2sx.mod
- -trimpath
env:
- CGO_ENABLED=0
goos:
- aix
- linux
- freebsd
- netbsd
- windows
- darwin
goarch:
- 386
- amd64
- arm
- arm64
- ppc64
- ppc64le
- mips64
- mips64le
goarm:
- 7
ignore:
- goos: windows
goarch: arm
archives:
-
id: s2-binaries
name_template: "s2-{{ .Os }}_{{ .Arch }}{{ if .Arm }}v{{ .Arm }}{{ end }}"
format_overrides:
- goos: windows
formats: ['zip']
files:
- unpack/*
- s2/LICENSE
- s2/README.md
checksum:
name_template: 'checksums.txt'
snapshot:
version_template: "{{ .Tag }}-next"
changelog:
sort: asc
filters:
exclude:
- '^doc:'
- '^docs:'
- '^test:'
- '^tests:'
- '^Update\sREADME.md'
nfpms:
-
file_name_template: "s2_package__{{ .Os }}_{{ .Arch }}{{ if .Arm }}v{{ .Arm }}{{ end }}"
vendor: Klaus Post
homepage: https://github.com/klauspost/compress
maintainer: Klaus Post <klauspost@gmail.com>
description: S2 Compression Tool
license: BSD 3-Clause
formats:
- deb
- rpm
Server/vendor/github.com/klauspost/compress/LICENSE
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Copyright (c) 2012 The Go Authors. All rights reserved.
Copyright (c) 2019 Klaus Post. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
------------------
Files: gzhttp/*
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------------------
Files: s2/cmd/internal/readahead/*
The MIT License (MIT)
Copyright (c) 2015 Klaus Post
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
---------------------
Files: snappy/*
Files: internal/snapref/*
Copyright (c) 2011 The Snappy-Go Authors. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-----------------
Files: s2/cmd/internal/filepathx/*
Copyright 2016 The filepathx Authors
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
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Server/vendor/github.com/klauspost/compress/README.md
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# compress
This package provides various compression algorithms.
* [zstandard](https://github.com/klauspost/compress/tree/master/zstd#zstd) compression and decompression in pure Go.
* [S2](https://github.com/klauspost/compress/tree/master/s2#s2-compression) is a high performance replacement for Snappy.
* Optimized [deflate](https://godoc.org/github.com/klauspost/compress/flate) packages which can be used as a dropin replacement for [gzip](https://godoc.org/github.com/klauspost/compress/gzip), [zip](https://godoc.org/github.com/klauspost/compress/zip) and [zlib](https://godoc.org/github.com/klauspost/compress/zlib).
* [snappy](https://github.com/klauspost/compress/tree/master/snappy) is a drop-in replacement for `github.com/golang/snappy` offering better compression and concurrent streams.
* [huff0](https://github.com/klauspost/compress/tree/master/huff0) and [FSE](https://github.com/klauspost/compress/tree/master/fse) implementations for raw entropy encoding.
* [gzhttp](https://github.com/klauspost/compress/tree/master/gzhttp) Provides client and server wrappers for handling gzipped/zstd HTTP requests efficiently.
* [pgzip](https://github.com/klauspost/pgzip) is a separate package that provides a very fast parallel gzip implementation.
[![Go Reference](https://pkg.go.dev/badge/klauspost/compress.svg)](https://pkg.go.dev/github.com/klauspost/compress?tab=subdirectories)
[![Go](https://github.com/klauspost/compress/actions/workflows/go.yml/badge.svg)](https://github.com/klauspost/compress/actions/workflows/go.yml)
[![Sourcegraph Badge](https://sourcegraph.com/github.com/klauspost/compress/-/badge.svg)](https://sourcegraph.com/github.com/klauspost/compress?badge)
# package usage
Use `go get github.com/klauspost/compress@latest` to add it to your project.
This package will support the current Go version and 2 versions back.
* Use the `nounsafe` tag to disable all use of the "unsafe" package.
* Use the `noasm` tag to disable all assembly across packages.
Use the links above for more information on each.
# changelog
* Feb 9th, 2026 [1.18.4](https://github.com/klauspost/compress/releases/tag/v1.18.4)
* gzhttp: Add zstandard to server handler wrapper https://github.com/klauspost/compress/pull/1121
* zstd: Add ResetWithOptions to encoder/decoder https://github.com/klauspost/compress/pull/1122
* gzhttp: preserve qvalue when extra parameters follow in Accept-Encoding by @analytically in https://github.com/klauspost/compress/pull/1116
* Jan 16th, 2026 [1.18.3](https://github.com/klauspost/compress/releases/tag/v1.18.3)
* Downstream CVE-2025-61728. See [golang/go#77102](https://github.com/golang/go/issues/77102).
* Dec 1st, 2025 - [1.18.2](https://github.com/klauspost/compress/releases/tag/v1.18.2)
* flate: Fix invalid encoding on level 9 with single value input in https://github.com/klauspost/compress/pull/1115
* flate: reduce stateless allocations by @RXamzin in https://github.com/klauspost/compress/pull/1106
* Oct 20, 2025 - [1.18.1](https://github.com/klauspost/compress/releases/tag/v1.18.1) - RETRACTED
* zstd: Add simple zstd EncodeTo/DecodeTo functions https://github.com/klauspost/compress/pull/1079
* zstd: Fix incorrect buffer size in dictionary encodes https://github.com/klauspost/compress/pull/1059
* s2: check for cap, not len of buffer in EncodeBetter/Best by @vdarulis in https://github.com/klauspost/compress/pull/1080
* zlib: Avoiding extra allocation in zlib.reader.Reset by @travelpolicy in https://github.com/klauspost/compress/pull/1086
* gzhttp: remove redundant err check in zstdReader by @ryanfowler in https://github.com/klauspost/compress/pull/1090
* flate: Faster load+store https://github.com/klauspost/compress/pull/1104
* flate: Simplify matchlen https://github.com/klauspost/compress/pull/1101
* flate: Use exact sizes for huffman tables https://github.com/klauspost/compress/pull/1103
* Feb 19th, 2025 - [1.18.0](https://github.com/klauspost/compress/releases/tag/v1.18.0)
* Add unsafe little endian loaders https://github.com/klauspost/compress/pull/1036
* fix: check `r.err != nil` but return a nil value error `err` by @alingse in https://github.com/klauspost/compress/pull/1028
* flate: Simplify L4-6 loading https://github.com/klauspost/compress/pull/1043
* flate: Simplify matchlen (remove asm) https://github.com/klauspost/compress/pull/1045
* s2: Improve small block compression speed w/o asm https://github.com/klauspost/compress/pull/1048
* flate: Fix matchlen L5+L6 https://github.com/klauspost/compress/pull/1049
* flate: Cleanup & reduce casts https://github.com/klauspost/compress/pull/1050
<details>
<summary>See changes to v1.17.x</summary>
* Oct 11th, 2024 - [1.17.11](https://github.com/klauspost/compress/releases/tag/v1.17.11)
* zstd: Fix extra CRC written with multiple Close calls https://github.com/klauspost/compress/pull/1017
* s2: Don't use stack for index tables https://github.com/klauspost/compress/pull/1014
* gzhttp: No content-type on no body response code by @juliens in https://github.com/klauspost/compress/pull/1011
* gzhttp: Do not set the content-type when response has no body by @kevinpollet in https://github.com/klauspost/compress/pull/1013
* Sep 23rd, 2024 - [1.17.10](https://github.com/klauspost/compress/releases/tag/v1.17.10)
* gzhttp: Add TransportAlwaysDecompress option. https://github.com/klauspost/compress/pull/978
* gzhttp: Add supported decompress request body by @mirecl in https://github.com/klauspost/compress/pull/1002
* s2: Add EncodeBuffer buffer recycling callback https://github.com/klauspost/compress/pull/982
* zstd: Improve memory usage on small streaming encodes https://github.com/klauspost/compress/pull/1007
* flate: read data written with partial flush by @vajexal in https://github.com/klauspost/compress/pull/996
* Jun 12th, 2024 - [1.17.9](https://github.com/klauspost/compress/releases/tag/v1.17.9)
* s2: Reduce ReadFrom temporary allocations https://github.com/klauspost/compress/pull/949
* flate, zstd: Shave some bytes off amd64 matchLen by @greatroar in https://github.com/klauspost/compress/pull/963
* Upgrade zip/zlib to 1.22.4 upstream https://github.com/klauspost/compress/pull/970 https://github.com/klauspost/compress/pull/971
* zstd: BuildDict fails with RLE table https://github.com/klauspost/compress/pull/951
* Apr 9th, 2024 - [1.17.8](https://github.com/klauspost/compress/releases/tag/v1.17.8)
* zstd: Reject blocks where reserved values are not 0 https://github.com/klauspost/compress/pull/885
* zstd: Add RLE detection+encoding https://github.com/klauspost/compress/pull/938
* Feb 21st, 2024 - [1.17.7](https://github.com/klauspost/compress/releases/tag/v1.17.7)
* s2: Add AsyncFlush method: Complete the block without flushing by @Jille in https://github.com/klauspost/compress/pull/927
* s2: Fix literal+repeat exceeds dst crash https://github.com/klauspost/compress/pull/930
* Feb 5th, 2024 - [1.17.6](https://github.com/klauspost/compress/releases/tag/v1.17.6)
* zstd: Fix incorrect repeat coding in best mode https://github.com/klauspost/compress/pull/923
* s2: Fix DecodeConcurrent deadlock on errors https://github.com/klauspost/compress/pull/925
* Jan 26th, 2024 - [v1.17.5](https://github.com/klauspost/compress/releases/tag/v1.17.5)
* flate: Fix reset with dictionary on custom window encodes https://github.com/klauspost/compress/pull/912
* zstd: Add Frame header encoding and stripping https://github.com/klauspost/compress/pull/908
* zstd: Limit better/best default window to 8MB https://github.com/klauspost/compress/pull/913
* zstd: Speed improvements by @greatroar in https://github.com/klauspost/compress/pull/896 https://github.com/klauspost/compress/pull/910
* s2: Fix callbacks for skippable blocks and disallow 0xfe (Padding) by @Jille in https://github.com/klauspost/compress/pull/916 https://github.com/klauspost/compress/pull/917
https://github.com/klauspost/compress/pull/919 https://github.com/klauspost/compress/pull/918
* Dec 1st, 2023 - [v1.17.4](https://github.com/klauspost/compress/releases/tag/v1.17.4)
* huff0: Speed up symbol counting by @greatroar in https://github.com/klauspost/compress/pull/887
* huff0: Remove byteReader by @greatroar in https://github.com/klauspost/compress/pull/886
* gzhttp: Allow overriding decompression on transport https://github.com/klauspost/compress/pull/892
* gzhttp: Clamp compression level https://github.com/klauspost/compress/pull/890
* gzip: Error out if reserved bits are set https://github.com/klauspost/compress/pull/891
* Nov 15th, 2023 - [v1.17.3](https://github.com/klauspost/compress/releases/tag/v1.17.3)
* fse: Fix max header size https://github.com/klauspost/compress/pull/881
* zstd: Improve better/best compression https://github.com/klauspost/compress/pull/877
* gzhttp: Fix missing content type on Close https://github.com/klauspost/compress/pull/883
* Oct 22nd, 2023 - [v1.17.2](https://github.com/klauspost/compress/releases/tag/v1.17.2)
* zstd: Fix rare *CORRUPTION* output in "best" mode. See https://github.com/klauspost/compress/pull/876
* Oct 14th, 2023 - [v1.17.1](https://github.com/klauspost/compress/releases/tag/v1.17.1)
* s2: Fix S2 "best" dictionary wrong encoding https://github.com/klauspost/compress/pull/871
* flate: Reduce allocations in decompressor and minor code improvements by @fakefloordiv in https://github.com/klauspost/compress/pull/869
* s2: Fix EstimateBlockSize on 6&7 length input https://github.com/klauspost/compress/pull/867
* Sept 19th, 2023 - [v1.17.0](https://github.com/klauspost/compress/releases/tag/v1.17.0)
* Add experimental dictionary builder https://github.com/klauspost/compress/pull/853
* Add xerial snappy read/writer https://github.com/klauspost/compress/pull/838
* flate: Add limited window compression https://github.com/klauspost/compress/pull/843
* s2: Do 2 overlapping match checks https://github.com/klauspost/compress/pull/839
* flate: Add amd64 assembly matchlen https://github.com/klauspost/compress/pull/837
* gzip: Copy bufio.Reader on Reset by @thatguystone in https://github.com/klauspost/compress/pull/860
</details>
<details>
<summary>See changes to v1.16.x</summary>
* July 1st, 2023 - [v1.16.7](https://github.com/klauspost/compress/releases/tag/v1.16.7)
* zstd: Fix default level first dictionary encode https://github.com/klauspost/compress/pull/829
* s2: add GetBufferCapacity() method by @GiedriusS in https://github.com/klauspost/compress/pull/832
* June 13, 2023 - [v1.16.6](https://github.com/klauspost/compress/releases/tag/v1.16.6)
* zstd: correctly ignore WithEncoderPadding(1) by @ianlancetaylor in https://github.com/klauspost/compress/pull/806
* zstd: Add amd64 match length assembly https://github.com/klauspost/compress/pull/824
* gzhttp: Handle informational headers by @rtribotte in https://github.com/klauspost/compress/pull/815
* s2: Improve Better compression slightly https://github.com/klauspost/compress/pull/663
* Apr 16, 2023 - [v1.16.5](https://github.com/klauspost/compress/releases/tag/v1.16.5)
* zstd: readByte needs to use io.ReadFull by @jnoxon in https://github.com/klauspost/compress/pull/802
* gzip: Fix WriterTo after initial read https://github.com/klauspost/compress/pull/804
* Apr 5, 2023 - [v1.16.4](https://github.com/klauspost/compress/releases/tag/v1.16.4)
* zstd: Improve zstd best efficiency by @greatroar and @klauspost in https://github.com/klauspost/compress/pull/784
* zstd: Respect WithAllLitEntropyCompression https://github.com/klauspost/compress/pull/792
* zstd: Fix amd64 not always detecting corrupt data https://github.com/klauspost/compress/pull/785
* zstd: Various minor improvements by @greatroar in https://github.com/klauspost/compress/pull/788 https://github.com/klauspost/compress/pull/794 https://github.com/klauspost/compress/pull/795
* s2: Fix huge block overflow https://github.com/klauspost/compress/pull/779
* s2: Allow CustomEncoder fallback https://github.com/klauspost/compress/pull/780
* gzhttp: Support ResponseWriter Unwrap() in gzhttp handler by @jgimenez in https://github.com/klauspost/compress/pull/799
* Mar 13, 2023 - [v1.16.1](https://github.com/klauspost/compress/releases/tag/v1.16.1)
* zstd: Speed up + improve best encoder by @greatroar in https://github.com/klauspost/compress/pull/776
* gzhttp: Add optional [BREACH mitigation](https://github.com/klauspost/compress/tree/master/gzhttp#breach-mitigation). https://github.com/klauspost/compress/pull/762 https://github.com/klauspost/compress/pull/768 https://github.com/klauspost/compress/pull/769 https://github.com/klauspost/compress/pull/770 https://github.com/klauspost/compress/pull/767
* s2: Add Intel LZ4s converter https://github.com/klauspost/compress/pull/766
* zstd: Minor bug fixes https://github.com/klauspost/compress/pull/771 https://github.com/klauspost/compress/pull/772 https://github.com/klauspost/compress/pull/773
* huff0: Speed up compress1xDo by @greatroar in https://github.com/klauspost/compress/pull/774
* Feb 26, 2023 - [v1.16.0](https://github.com/klauspost/compress/releases/tag/v1.16.0)
* s2: Add [Dictionary](https://github.com/klauspost/compress/tree/master/s2#dictionaries) support. https://github.com/klauspost/compress/pull/685
* s2: Add Compression Size Estimate. https://github.com/klauspost/compress/pull/752
* s2: Add support for custom stream encoder. https://github.com/klauspost/compress/pull/755
* s2: Add LZ4 block converter. https://github.com/klauspost/compress/pull/748
* s2: Support io.ReaderAt in ReadSeeker. https://github.com/klauspost/compress/pull/747
* s2c/s2sx: Use concurrent decoding. https://github.com/klauspost/compress/pull/746
</details>
<details>
<summary>See changes to v1.15.x</summary>
* Jan 21st, 2023 (v1.15.15)
* deflate: Improve level 7-9 https://github.com/klauspost/compress/pull/739
* zstd: Add delta encoding support by @greatroar in https://github.com/klauspost/compress/pull/728
* zstd: Various speed improvements by @greatroar https://github.com/klauspost/compress/pull/741 https://github.com/klauspost/compress/pull/734 https://github.com/klauspost/compress/pull/736 https://github.com/klauspost/compress/pull/744 https://github.com/klauspost/compress/pull/743 https://github.com/klauspost/compress/pull/745
* gzhttp: Add SuffixETag() and DropETag() options to prevent ETag collisions on compressed responses by @willbicks in https://github.com/klauspost/compress/pull/740
* Jan 3rd, 2023 (v1.15.14)
* flate: Improve speed in big stateless blocks https://github.com/klauspost/compress/pull/718
* zstd: Minor speed tweaks by @greatroar in https://github.com/klauspost/compress/pull/716 https://github.com/klauspost/compress/pull/720
* export NoGzipResponseWriter for custom ResponseWriter wrappers by @harshavardhana in https://github.com/klauspost/compress/pull/722
* s2: Add example for indexing and existing stream https://github.com/klauspost/compress/pull/723
* Dec 11, 2022 (v1.15.13)
* zstd: Add [MaxEncodedSize](https://pkg.go.dev/github.com/klauspost/compress@v1.15.13/zstd#Encoder.MaxEncodedSize) to encoder https://github.com/klauspost/compress/pull/691
* zstd: Various tweaks and improvements https://github.com/klauspost/compress/pull/693 https://github.com/klauspost/compress/pull/695 https://github.com/klauspost/compress/pull/696 https://github.com/klauspost/compress/pull/701 https://github.com/klauspost/compress/pull/702 https://github.com/klauspost/compress/pull/703 https://github.com/klauspost/compress/pull/704 https://github.com/klauspost/compress/pull/705 https://github.com/klauspost/compress/pull/706 https://github.com/klauspost/compress/pull/707 https://github.com/klauspost/compress/pull/708
* Oct 26, 2022 (v1.15.12)
* zstd: Tweak decoder allocs. https://github.com/klauspost/compress/pull/680
* gzhttp: Always delete `HeaderNoCompression` https://github.com/klauspost/compress/pull/683
* Sept 26, 2022 (v1.15.11)
* flate: Improve level 1-3 compression https://github.com/klauspost/compress/pull/678
* zstd: Improve "best" compression by @nightwolfz in https://github.com/klauspost/compress/pull/677
* zstd: Fix+reduce decompression allocations https://github.com/klauspost/compress/pull/668
* zstd: Fix non-effective noescape tag https://github.com/klauspost/compress/pull/667
* Sept 16, 2022 (v1.15.10)
* zstd: Add [WithDecodeAllCapLimit](https://pkg.go.dev/github.com/klauspost/compress@v1.15.10/zstd#WithDecodeAllCapLimit) https://github.com/klauspost/compress/pull/649
* Add Go 1.19 - deprecate Go 1.16 https://github.com/klauspost/compress/pull/651
* flate: Improve level 5+6 compression https://github.com/klauspost/compress/pull/656
* zstd: Improve "better" compression https://github.com/klauspost/compress/pull/657
* s2: Improve "best" compression https://github.com/klauspost/compress/pull/658
* s2: Improve "better" compression. https://github.com/klauspost/compress/pull/635
* s2: Slightly faster non-assembly decompression https://github.com/klauspost/compress/pull/646
* Use arrays for constant size copies https://github.com/klauspost/compress/pull/659
* July 21, 2022 (v1.15.9)
* zstd: Fix decoder crash on amd64 (no BMI) on invalid input https://github.com/klauspost/compress/pull/645
* zstd: Disable decoder extended memory copies (amd64) due to possible crashes https://github.com/klauspost/compress/pull/644
* zstd: Allow single segments up to "max decoded size" https://github.com/klauspost/compress/pull/643
* July 13, 2022 (v1.15.8)
* gzip: fix stack exhaustion bug in Reader.Read https://github.com/klauspost/compress/pull/641
* s2: Add Index header trim/restore https://github.com/klauspost/compress/pull/638
* zstd: Optimize seqdeq amd64 asm by @greatroar in https://github.com/klauspost/compress/pull/636
* zstd: Improve decoder memcopy https://github.com/klauspost/compress/pull/637
* huff0: Pass a single bitReader pointer to asm by @greatroar in https://github.com/klauspost/compress/pull/634
* zstd: Branchless getBits for amd64 w/o BMI2 by @greatroar in https://github.com/klauspost/compress/pull/640
* gzhttp: Remove header before writing https://github.com/klauspost/compress/pull/639
* June 29, 2022 (v1.15.7)
* s2: Fix absolute forward seeks https://github.com/klauspost/compress/pull/633
* zip: Merge upstream https://github.com/klauspost/compress/pull/631
* zip: Re-add zip64 fix https://github.com/klauspost/compress/pull/624
* zstd: translate fseDecoder.buildDtable into asm by @WojciechMula in https://github.com/klauspost/compress/pull/598
* flate: Faster histograms https://github.com/klauspost/compress/pull/620
* deflate: Use compound hcode https://github.com/klauspost/compress/pull/622
* June 3, 2022 (v1.15.6)
* s2: Improve coding for long, close matches https://github.com/klauspost/compress/pull/613
* s2c: Add Snappy/S2 stream recompression https://github.com/klauspost/compress/pull/611
* zstd: Always use configured block size https://github.com/klauspost/compress/pull/605
* zstd: Fix incorrect hash table placement for dict encoding in default https://github.com/klauspost/compress/pull/606
* zstd: Apply default config to ZipDecompressor without options https://github.com/klauspost/compress/pull/608
* gzhttp: Exclude more common archive formats https://github.com/klauspost/compress/pull/612
* s2: Add ReaderIgnoreCRC https://github.com/klauspost/compress/pull/609
* s2: Remove sanity load on index creation https://github.com/klauspost/compress/pull/607
* snappy: Use dedicated function for scoring https://github.com/klauspost/compress/pull/614
* s2c+s2d: Use official snappy framed extension https://github.com/klauspost/compress/pull/610
* May 25, 2022 (v1.15.5)
* s2: Add concurrent stream decompression https://github.com/klauspost/compress/pull/602
* s2: Fix final emit oob read crash on amd64 https://github.com/klauspost/compress/pull/601
* huff0: asm implementation of Decompress1X by @WojciechMula https://github.com/klauspost/compress/pull/596
* zstd: Use 1 less goroutine for stream decoding https://github.com/klauspost/compress/pull/588
* zstd: Copy literal in 16 byte blocks when possible https://github.com/klauspost/compress/pull/592
* zstd: Speed up when WithDecoderLowmem(false) https://github.com/klauspost/compress/pull/599
* zstd: faster next state update in BMI2 version of decode by @WojciechMula in https://github.com/klauspost/compress/pull/593
* huff0: Do not check max size when reading table. https://github.com/klauspost/compress/pull/586
* flate: Inplace hashing for level 7-9 https://github.com/klauspost/compress/pull/590
* May 11, 2022 (v1.15.4)
* huff0: decompress directly into output by @WojciechMula in [#577](https://github.com/klauspost/compress/pull/577)
* inflate: Keep dict on stack [#581](https://github.com/klauspost/compress/pull/581)
* zstd: Faster decoding memcopy in asm [#583](https://github.com/klauspost/compress/pull/583)
* zstd: Fix ignored crc [#580](https://github.com/klauspost/compress/pull/580)
* May 5, 2022 (v1.15.3)
* zstd: Allow to ignore checksum checking by @WojciechMula [#572](https://github.com/klauspost/compress/pull/572)
* s2: Fix incorrect seek for io.SeekEnd in [#575](https://github.com/klauspost/compress/pull/575)
* Apr 26, 2022 (v1.15.2)
* zstd: Add x86-64 assembly for decompression on streams and blocks. Contributed by [@WojciechMula](https://github.com/WojciechMula). Typically 2x faster. [#528](https://github.com/klauspost/compress/pull/528) [#531](https://github.com/klauspost/compress/pull/531) [#545](https://github.com/klauspost/compress/pull/545) [#537](https://github.com/klauspost/compress/pull/537)
* zstd: Add options to ZipDecompressor and fixes [#539](https://github.com/klauspost/compress/pull/539)
* s2: Use sorted search for index [#555](https://github.com/klauspost/compress/pull/555)
* Minimum version is Go 1.16, added CI test on 1.18.
* Mar 11, 2022 (v1.15.1)
* huff0: Add x86 assembly of Decode4X by @WojciechMula in [#512](https://github.com/klauspost/compress/pull/512)
* zstd: Reuse zip decoders in [#514](https://github.com/klauspost/compress/pull/514)
* zstd: Detect extra block data and report as corrupted in [#520](https://github.com/klauspost/compress/pull/520)
* zstd: Handle zero sized frame content size stricter in [#521](https://github.com/klauspost/compress/pull/521)
* zstd: Add stricter block size checks in [#523](https://github.com/klauspost/compress/pull/523)
* Mar 3, 2022 (v1.15.0)
* zstd: Refactor decoder [#498](https://github.com/klauspost/compress/pull/498)
* zstd: Add stream encoding without goroutines [#505](https://github.com/klauspost/compress/pull/505)
* huff0: Prevent single blocks exceeding 16 bits by @klauspost in[#507](https://github.com/klauspost/compress/pull/507)
* flate: Inline literal emission [#509](https://github.com/klauspost/compress/pull/509)
* gzhttp: Add zstd to transport [#400](https://github.com/klauspost/compress/pull/400)
* gzhttp: Make content-type optional [#510](https://github.com/klauspost/compress/pull/510)
Both compression and decompression now supports "synchronous" stream operations. This means that whenever "concurrency" is set to 1, they will operate without spawning goroutines.
Stream decompression is now faster on asynchronous, since the goroutine allocation much more effectively splits the workload. On typical streams this will typically use 2 cores fully for decompression. When a stream has finished decoding no goroutines will be left over, so decoders can now safely be pooled and still be garbage collected.
While the release has been extensively tested, it is recommended to testing when upgrading.
</details>
<details>
<summary>See changes to v1.14.x</summary>
* Feb 22, 2022 (v1.14.4)
* flate: Fix rare huffman only (-2) corruption. [#503](https://github.com/klauspost/compress/pull/503)
* zip: Update deprecated CreateHeaderRaw to correctly call CreateRaw by @saracen in [#502](https://github.com/klauspost/compress/pull/502)
* zip: don't read data descriptor early by @saracen in [#501](https://github.com/klauspost/compress/pull/501) #501
* huff0: Use static decompression buffer up to 30% faster [#499](https://github.com/klauspost/compress/pull/499) [#500](https://github.com/klauspost/compress/pull/500)
* Feb 17, 2022 (v1.14.3)
* flate: Improve fastest levels compression speed ~10% more throughput. [#482](https://github.com/klauspost/compress/pull/482) [#489](https://github.com/klauspost/compress/pull/489) [#490](https://github.com/klauspost/compress/pull/490) [#491](https://github.com/klauspost/compress/pull/491) [#494](https://github.com/klauspost/compress/pull/494) [#478](https://github.com/klauspost/compress/pull/478)
* flate: Faster decompression speed, ~5-10%. [#483](https://github.com/klauspost/compress/pull/483)
* s2: Faster compression with Go v1.18 and amd64 microarch level 3+. [#484](https://github.com/klauspost/compress/pull/484) [#486](https://github.com/klauspost/compress/pull/486)
* Jan 25, 2022 (v1.14.2)
* zstd: improve header decoder by @dsnet [#476](https://github.com/klauspost/compress/pull/476)
* zstd: Add bigger default blocks [#469](https://github.com/klauspost/compress/pull/469)
* zstd: Remove unused decompression buffer [#470](https://github.com/klauspost/compress/pull/470)
* zstd: Fix logically dead code by @ningmingxiao [#472](https://github.com/klauspost/compress/pull/472)
* flate: Improve level 7-9 [#471](https://github.com/klauspost/compress/pull/471) [#473](https://github.com/klauspost/compress/pull/473)
* zstd: Add noasm tag for xxhash [#475](https://github.com/klauspost/compress/pull/475)
* Jan 11, 2022 (v1.14.1)
* s2: Add stream index in [#462](https://github.com/klauspost/compress/pull/462)
* flate: Speed and efficiency improvements in [#439](https://github.com/klauspost/compress/pull/439) [#461](https://github.com/klauspost/compress/pull/461) [#455](https://github.com/klauspost/compress/pull/455) [#452](https://github.com/klauspost/compress/pull/452) [#458](https://github.com/klauspost/compress/pull/458)
* zstd: Performance improvement in [#420]( https://github.com/klauspost/compress/pull/420) [#456](https://github.com/klauspost/compress/pull/456) [#437](https://github.com/klauspost/compress/pull/437) [#467](https://github.com/klauspost/compress/pull/467) [#468](https://github.com/klauspost/compress/pull/468)
* zstd: add arm64 xxhash assembly in [#464](https://github.com/klauspost/compress/pull/464)
* Add garbled for binaries for s2 in [#445](https://github.com/klauspost/compress/pull/445)
</details>
<details>
<summary>See changes to v1.13.x</summary>
* Aug 30, 2021 (v1.13.5)
* gz/zlib/flate: Alias stdlib errors [#425](https://github.com/klauspost/compress/pull/425)
* s2: Add block support to commandline tools [#413](https://github.com/klauspost/compress/pull/413)
* zstd: pooledZipWriter should return Writers to the same pool [#426](https://github.com/klauspost/compress/pull/426)
* Removed golang/snappy as external dependency for tests [#421](https://github.com/klauspost/compress/pull/421)
* Aug 12, 2021 (v1.13.4)
* Add [snappy replacement package](https://github.com/klauspost/compress/tree/master/snappy).
* zstd: Fix incorrect encoding in "best" mode [#415](https://github.com/klauspost/compress/pull/415)
* Aug 3, 2021 (v1.13.3)
* zstd: Improve Best compression [#404](https://github.com/klauspost/compress/pull/404)
* zstd: Fix WriteTo error forwarding [#411](https://github.com/klauspost/compress/pull/411)
* gzhttp: Return http.HandlerFunc instead of http.Handler. Unlikely breaking change. [#406](https://github.com/klauspost/compress/pull/406)
* s2sx: Fix max size error [#399](https://github.com/klauspost/compress/pull/399)
* zstd: Add optional stream content size on reset [#401](https://github.com/klauspost/compress/pull/401)
* zstd: use SpeedBestCompression for level >= 10 [#410](https://github.com/klauspost/compress/pull/410)
* Jun 14, 2021 (v1.13.1)
* s2: Add full Snappy output support [#396](https://github.com/klauspost/compress/pull/396)
* zstd: Add configurable [Decoder window](https://pkg.go.dev/github.com/klauspost/compress/zstd#WithDecoderMaxWindow) size [#394](https://github.com/klauspost/compress/pull/394)
* gzhttp: Add header to skip compression [#389](https://github.com/klauspost/compress/pull/389)
* s2: Improve speed with bigger output margin [#395](https://github.com/klauspost/compress/pull/395)
* Jun 3, 2021 (v1.13.0)
* Added [gzhttp](https://github.com/klauspost/compress/tree/master/gzhttp#gzip-handler) which allows wrapping HTTP servers and clients with GZIP compressors.
* zstd: Detect short invalid signatures [#382](https://github.com/klauspost/compress/pull/382)
* zstd: Spawn decoder goroutine only if needed. [#380](https://github.com/klauspost/compress/pull/380)
</details>
<details>
<summary>See changes to v1.12.x</summary>
* May 25, 2021 (v1.12.3)
* deflate: Better/faster Huffman encoding [#374](https://github.com/klauspost/compress/pull/374)
* deflate: Allocate less for history. [#375](https://github.com/klauspost/compress/pull/375)
* zstd: Forward read errors [#373](https://github.com/klauspost/compress/pull/373)
* Apr 27, 2021 (v1.12.2)
* zstd: Improve better/best compression [#360](https://github.com/klauspost/compress/pull/360) [#364](https://github.com/klauspost/compress/pull/364) [#365](https://github.com/klauspost/compress/pull/365)
* zstd: Add helpers to compress/decompress zstd inside zip files [#363](https://github.com/klauspost/compress/pull/363)
* deflate: Improve level 5+6 compression [#367](https://github.com/klauspost/compress/pull/367)
* s2: Improve better/best compression [#358](https://github.com/klauspost/compress/pull/358) [#359](https://github.com/klauspost/compress/pull/358)
* s2: Load after checking src limit on amd64. [#362](https://github.com/klauspost/compress/pull/362)
* s2sx: Limit max executable size [#368](https://github.com/klauspost/compress/pull/368)
* Apr 14, 2021 (v1.12.1)
* snappy package removed. Upstream added as dependency.
* s2: Better compression in "best" mode [#353](https://github.com/klauspost/compress/pull/353)
* s2sx: Add stdin input and detect pre-compressed from signature [#352](https://github.com/klauspost/compress/pull/352)
* s2c/s2d: Add http as possible input [#348](https://github.com/klauspost/compress/pull/348)
* s2c/s2d/s2sx: Always truncate when writing files [#352](https://github.com/klauspost/compress/pull/352)
* zstd: Reduce memory usage further when using [WithLowerEncoderMem](https://pkg.go.dev/github.com/klauspost/compress/zstd#WithLowerEncoderMem) [#346](https://github.com/klauspost/compress/pull/346)
* s2: Fix potential problem with amd64 assembly and profilers [#349](https://github.com/klauspost/compress/pull/349)
</details>
<details>
<summary>See changes to v1.11.x</summary>
* Mar 26, 2021 (v1.11.13)
* zstd: Big speedup on small dictionary encodes [#344](https://github.com/klauspost/compress/pull/344) [#345](https://github.com/klauspost/compress/pull/345)
* zstd: Add [WithLowerEncoderMem](https://pkg.go.dev/github.com/klauspost/compress/zstd#WithLowerEncoderMem) encoder option [#336](https://github.com/klauspost/compress/pull/336)
* deflate: Improve entropy compression [#338](https://github.com/klauspost/compress/pull/338)
* s2: Clean up and minor performance improvement in best [#341](https://github.com/klauspost/compress/pull/341)
* Mar 5, 2021 (v1.11.12)
* s2: Add `s2sx` binary that creates [self extracting archives](https://github.com/klauspost/compress/tree/master/s2#s2sx-self-extracting-archives).
* s2: Speed up decompression on non-assembly platforms [#328](https://github.com/klauspost/compress/pull/328)
* Mar 1, 2021 (v1.11.9)
* s2: Add ARM64 decompression assembly. Around 2x output speed. [#324](https://github.com/klauspost/compress/pull/324)
* s2: Improve "better" speed and efficiency. [#325](https://github.com/klauspost/compress/pull/325)
* s2: Fix binaries.
* Feb 25, 2021 (v1.11.8)
* s2: Fixed occasional out-of-bounds write on amd64. Upgrade recommended.
* s2: Add AMD64 assembly for better mode. 25-50% faster. [#315](https://github.com/klauspost/compress/pull/315)
* s2: Less upfront decoder allocation. [#322](https://github.com/klauspost/compress/pull/322)
* zstd: Faster "compression" of incompressible data. [#314](https://github.com/klauspost/compress/pull/314)
* zip: Fix zip64 headers. [#313](https://github.com/klauspost/compress/pull/313)
* Jan 14, 2021 (v1.11.7)
* Use Bytes() interface to get bytes across packages. [#309](https://github.com/klauspost/compress/pull/309)
* s2: Add 'best' compression option. [#310](https://github.com/klauspost/compress/pull/310)
* s2: Add ReaderMaxBlockSize, changes `s2.NewReader` signature to include varargs. [#311](https://github.com/klauspost/compress/pull/311)
* s2: Fix crash on small better buffers. [#308](https://github.com/klauspost/compress/pull/308)
* s2: Clean up decoder. [#312](https://github.com/klauspost/compress/pull/312)
* Jan 7, 2021 (v1.11.6)
* zstd: Make decoder allocations smaller [#306](https://github.com/klauspost/compress/pull/306)
* zstd: Free Decoder resources when Reset is called with a nil io.Reader [#305](https://github.com/klauspost/compress/pull/305)
* Dec 20, 2020 (v1.11.4)
* zstd: Add Best compression mode [#304](https://github.com/klauspost/compress/pull/304)
* Add header decoder [#299](https://github.com/klauspost/compress/pull/299)
* s2: Add uncompressed stream option [#297](https://github.com/klauspost/compress/pull/297)
* Simplify/speed up small blocks with known max size. [#300](https://github.com/klauspost/compress/pull/300)
* zstd: Always reset literal dict encoder [#303](https://github.com/klauspost/compress/pull/303)
* Nov 15, 2020 (v1.11.3)
* inflate: 10-15% faster decompression [#293](https://github.com/klauspost/compress/pull/293)
* zstd: Tweak DecodeAll default allocation [#295](https://github.com/klauspost/compress/pull/295)
* Oct 11, 2020 (v1.11.2)
* s2: Fix out of bounds read in "better" block compression [#291](https://github.com/klauspost/compress/pull/291)
* Oct 1, 2020 (v1.11.1)
* zstd: Set allLitEntropy true in default configuration [#286](https://github.com/klauspost/compress/pull/286)
* Sept 8, 2020 (v1.11.0)
* zstd: Add experimental compression [dictionaries](https://github.com/klauspost/compress/tree/master/zstd#dictionaries) [#281](https://github.com/klauspost/compress/pull/281)
* zstd: Fix mixed Write and ReadFrom calls [#282](https://github.com/klauspost/compress/pull/282)
* inflate/gz: Limit variable shifts, ~5% faster decompression [#274](https://github.com/klauspost/compress/pull/274)
</details>
<details>
<summary>See changes to v1.10.x</summary>
* July 8, 2020 (v1.10.11)
* zstd: Fix extra block when compressing with ReadFrom. [#278](https://github.com/klauspost/compress/pull/278)
* huff0: Also populate compression table when reading decoding table. [#275](https://github.com/klauspost/compress/pull/275)
* June 23, 2020 (v1.10.10)
* zstd: Skip entropy compression in fastest mode when no matches. [#270](https://github.com/klauspost/compress/pull/270)
* June 16, 2020 (v1.10.9):
* zstd: API change for specifying dictionaries. See [#268](https://github.com/klauspost/compress/pull/268)
* zip: update CreateHeaderRaw to handle zip64 fields. [#266](https://github.com/klauspost/compress/pull/266)
* Fuzzit tests removed. The service has been purchased and is no longer available.
* June 5, 2020 (v1.10.8):
* 1.15x faster zstd block decompression. [#265](https://github.com/klauspost/compress/pull/265)
* June 1, 2020 (v1.10.7):
* Added zstd decompression [dictionary support](https://github.com/klauspost/compress/tree/master/zstd#dictionaries)
* Increase zstd decompression speed up to 1.19x. [#259](https://github.com/klauspost/compress/pull/259)
* Remove internal reset call in zstd compression and reduce allocations. [#263](https://github.com/klauspost/compress/pull/263)
* May 21, 2020: (v1.10.6)
* zstd: Reduce allocations while decoding. [#258](https://github.com/klauspost/compress/pull/258), [#252](https://github.com/klauspost/compress/pull/252)
* zstd: Stricter decompression checks.
* April 12, 2020: (v1.10.5)
* s2-commands: Flush output when receiving SIGINT. [#239](https://github.com/klauspost/compress/pull/239)
* Apr 8, 2020: (v1.10.4)
* zstd: Minor/special case optimizations. [#251](https://github.com/klauspost/compress/pull/251), [#250](https://github.com/klauspost/compress/pull/250), [#249](https://github.com/klauspost/compress/pull/249), [#247](https://github.com/klauspost/compress/pull/247)
* Mar 11, 2020: (v1.10.3)
* s2: Use S2 encoder in pure Go mode for Snappy output as well. [#245](https://github.com/klauspost/compress/pull/245)
* s2: Fix pure Go block encoder. [#244](https://github.com/klauspost/compress/pull/244)
* zstd: Added "better compression" mode. [#240](https://github.com/klauspost/compress/pull/240)
* zstd: Improve speed of fastest compression mode by 5-10% [#241](https://github.com/klauspost/compress/pull/241)
* zstd: Skip creating encoders when not needed. [#238](https://github.com/klauspost/compress/pull/238)
* Feb 27, 2020: (v1.10.2)
* Close to 50% speedup in inflate (gzip/zip decompression). [#236](https://github.com/klauspost/compress/pull/236) [#234](https://github.com/klauspost/compress/pull/234) [#232](https://github.com/klauspost/compress/pull/232)
* Reduce deflate level 1-6 memory usage up to 59%. [#227](https://github.com/klauspost/compress/pull/227)
* Feb 18, 2020: (v1.10.1)
* Fix zstd crash when resetting multiple times without sending data. [#226](https://github.com/klauspost/compress/pull/226)
* deflate: Fix dictionary use on level 1-6. [#224](https://github.com/klauspost/compress/pull/224)
* Remove deflate writer reference when closing. [#224](https://github.com/klauspost/compress/pull/224)
* Feb 4, 2020: (v1.10.0)
* Add optional dictionary to [stateless deflate](https://pkg.go.dev/github.com/klauspost/compress/flate?tab=doc#StatelessDeflate). Breaking change, send `nil` for previous behaviour. [#216](https://github.com/klauspost/compress/pull/216)
* Fix buffer overflow on repeated small block deflate. [#218](https://github.com/klauspost/compress/pull/218)
* Allow copying content from an existing ZIP file without decompressing+compressing. [#214](https://github.com/klauspost/compress/pull/214)
* Added [S2](https://github.com/klauspost/compress/tree/master/s2#s2-compression) AMD64 assembler and various optimizations. Stream speed >10GB/s. [#186](https://github.com/klauspost/compress/pull/186)
</details>
<details>
<summary>See changes prior to v1.10.0</summary>
* Jan 20,2020 (v1.9.8) Optimize gzip/deflate with better size estimates and faster table generation. [#207](https://github.com/klauspost/compress/pull/207) by [luyu6056](https://github.com/luyu6056), [#206](https://github.com/klauspost/compress/pull/206).
* Jan 11, 2020: S2 Encode/Decode will use provided buffer if capacity is big enough. [#204](https://github.com/klauspost/compress/pull/204)
* Jan 5, 2020: (v1.9.7) Fix another zstd regression in v1.9.5 - v1.9.6 removed.
* Jan 4, 2020: (v1.9.6) Regression in v1.9.5 fixed causing corrupt zstd encodes in rare cases.
* Jan 4, 2020: Faster IO in [s2c + s2d commandline tools](https://github.com/klauspost/compress/tree/master/s2#commandline-tools) compression/decompression. [#192](https://github.com/klauspost/compress/pull/192)
* Dec 29, 2019: Removed v1.9.5 since fuzz tests showed a compatibility problem with the reference zstandard decoder.
* Dec 29, 2019: (v1.9.5) zstd: 10-20% faster block compression. [#199](https://github.com/klauspost/compress/pull/199)
* Dec 29, 2019: [zip](https://godoc.org/github.com/klauspost/compress/zip) package updated with latest Go features
* Dec 29, 2019: zstd: Single segment flag condintions tweaked. [#197](https://github.com/klauspost/compress/pull/197)
* Dec 18, 2019: s2: Faster compression when ReadFrom is used. [#198](https://github.com/klauspost/compress/pull/198)
* Dec 10, 2019: s2: Fix repeat length output when just above at 16MB limit.
* Dec 10, 2019: zstd: Add function to get decoder as io.ReadCloser. [#191](https://github.com/klauspost/compress/pull/191)
* Dec 3, 2019: (v1.9.4) S2: limit max repeat length. [#188](https://github.com/klauspost/compress/pull/188)
* Dec 3, 2019: Add [WithNoEntropyCompression](https://godoc.org/github.com/klauspost/compress/zstd#WithNoEntropyCompression) to zstd [#187](https://github.com/klauspost/compress/pull/187)
* Dec 3, 2019: Reduce memory use for tests. Check for leaked goroutines.
* Nov 28, 2019 (v1.9.3) Less allocations in stateless deflate.
* Nov 28, 2019: 5-20% Faster huff0 decode. Impacts zstd as well. [#184](https://github.com/klauspost/compress/pull/184)
* Nov 12, 2019 (v1.9.2) Added [Stateless Compression](#stateless-compression) for gzip/deflate.
* Nov 12, 2019: Fixed zstd decompression of large single blocks. [#180](https://github.com/klauspost/compress/pull/180)
* Nov 11, 2019: Set default [s2c](https://github.com/klauspost/compress/tree/master/s2#commandline-tools) block size to 4MB.
* Nov 11, 2019: Reduce inflate memory use by 1KB.
* Nov 10, 2019: Less allocations in deflate bit writer.
* Nov 10, 2019: Fix inconsistent error returned by zstd decoder.
* Oct 28, 2019 (v1.9.1) ztsd: Fix crash when compressing blocks. [#174](https://github.com/klauspost/compress/pull/174)
* Oct 24, 2019 (v1.9.0) zstd: Fix rare data corruption [#173](https://github.com/klauspost/compress/pull/173)
* Oct 24, 2019 zstd: Fix huff0 out of buffer write [#171](https://github.com/klauspost/compress/pull/171) and always return errors [#172](https://github.com/klauspost/compress/pull/172)
* Oct 10, 2019: Big deflate rewrite, 30-40% faster with better compression [#105](https://github.com/klauspost/compress/pull/105)
</details>
<details>
<summary>See changes prior to v1.9.0</summary>
* Oct 10, 2019: (v1.8.6) zstd: Allow partial reads to get flushed data. [#169](https://github.com/klauspost/compress/pull/169)
* Oct 3, 2019: Fix inconsistent results on broken zstd streams.
* Sep 25, 2019: Added `-rm` (remove source files) and `-q` (no output except errors) to `s2c` and `s2d` [commands](https://github.com/klauspost/compress/tree/master/s2#commandline-tools)
* Sep 16, 2019: (v1.8.4) Add `s2c` and `s2d` [commandline tools](https://github.com/klauspost/compress/tree/master/s2#commandline-tools).
* Sep 10, 2019: (v1.8.3) Fix s2 decoder [Skip](https://godoc.org/github.com/klauspost/compress/s2#Reader.Skip).
* Sep 7, 2019: zstd: Added [WithWindowSize](https://godoc.org/github.com/klauspost/compress/zstd#WithWindowSize), contributed by [ianwilkes](https://github.com/ianwilkes).
* Sep 5, 2019: (v1.8.2) Add [WithZeroFrames](https://godoc.org/github.com/klauspost/compress/zstd#WithZeroFrames) which adds full zero payload block encoding option.
* Sep 5, 2019: Lazy initialization of zstandard predefined en/decoder tables.
* Aug 26, 2019: (v1.8.1) S2: 1-2% compression increase in "better" compression mode.
* Aug 26, 2019: zstd: Check maximum size of Huffman 1X compressed literals while decoding.
* Aug 24, 2019: (v1.8.0) Added [S2 compression](https://github.com/klauspost/compress/tree/master/s2#s2-compression), a high performance replacement for Snappy.
* Aug 21, 2019: (v1.7.6) Fixed minor issues found by fuzzer. One could lead to zstd not decompressing.
* Aug 18, 2019: Add [fuzzit](https://fuzzit.dev/) continuous fuzzing.
* Aug 14, 2019: zstd: Skip incompressible data 2x faster. [#147](https://github.com/klauspost/compress/pull/147)
* Aug 4, 2019 (v1.7.5): Better literal compression. [#146](https://github.com/klauspost/compress/pull/146)
* Aug 4, 2019: Faster zstd compression. [#143](https://github.com/klauspost/compress/pull/143) [#144](https://github.com/klauspost/compress/pull/144)
* Aug 4, 2019: Faster zstd decompression. [#145](https://github.com/klauspost/compress/pull/145) [#143](https://github.com/klauspost/compress/pull/143) [#142](https://github.com/klauspost/compress/pull/142)
* July 15, 2019 (v1.7.4): Fix double EOF block in rare cases on zstd encoder.
* July 15, 2019 (v1.7.3): Minor speedup/compression increase in default zstd encoder.
* July 14, 2019: zstd decoder: Fix decompression error on multiple uses with mixed content.
* July 7, 2019 (v1.7.2): Snappy update, zstd decoder potential race fix.
* June 17, 2019: zstd decompression bugfix.
* June 17, 2019: fix 32 bit builds.
* June 17, 2019: Easier use in modules (less dependencies).
* June 9, 2019: New stronger "default" [zstd](https://github.com/klauspost/compress/tree/master/zstd#zstd) compression mode. Matches zstd default compression ratio.
* June 5, 2019: 20-40% throughput in [zstandard](https://github.com/klauspost/compress/tree/master/zstd#zstd) compression and better compression.
* June 5, 2019: deflate/gzip compression: Reduce memory usage of lower compression levels.
* June 2, 2019: Added [zstandard](https://github.com/klauspost/compress/tree/master/zstd#zstd) compression!
* May 25, 2019: deflate/gzip: 10% faster bit writer, mostly visible in lower levels.
* Apr 22, 2019: [zstd](https://github.com/klauspost/compress/tree/master/zstd#zstd) decompression added.
* Aug 1, 2018: Added [huff0 README](https://github.com/klauspost/compress/tree/master/huff0#huff0-entropy-compression).
* Jul 8, 2018: Added [Performance Update 2018](#performance-update-2018) below.
* Jun 23, 2018: Merged [Go 1.11 inflate optimizations](https://go-review.googlesource.com/c/go/+/102235). Go 1.9 is now required. Backwards compatible version tagged with [v1.3.0](https://github.com/klauspost/compress/releases/tag/v1.3.0).
* Apr 2, 2018: Added [huff0](https://godoc.org/github.com/klauspost/compress/huff0) en/decoder. Experimental for now, API may change.
* Mar 4, 2018: Added [FSE Entropy](https://godoc.org/github.com/klauspost/compress/fse) en/decoder. Experimental for now, API may change.
* Nov 3, 2017: Add compression [Estimate](https://godoc.org/github.com/klauspost/compress#Estimate) function.
* May 28, 2017: Reduce allocations when resetting decoder.
* Apr 02, 2017: Change back to official crc32, since changes were merged in Go 1.7.
* Jan 14, 2017: Reduce stack pressure due to array copies. See [Issue #18625](https://github.com/golang/go/issues/18625).
* Oct 25, 2016: Level 2-4 have been rewritten and now offers significantly better performance than before.
* Oct 20, 2016: Port zlib changes from Go 1.7 to fix zlib writer issue. Please update.
* Oct 16, 2016: Go 1.7 changes merged. Apples to apples this package is a few percent faster, but has a significantly better balance between speed and compression per level.
* Mar 24, 2016: Always attempt Huffman encoding on level 4-7. This improves base 64 encoded data compression.
* Mar 24, 2016: Small speedup for level 1-3.
* Feb 19, 2016: Faster bit writer, level -2 is 15% faster, level 1 is 4% faster.
* Feb 19, 2016: Handle small payloads faster in level 1-3.
* Feb 19, 2016: Added faster level 2 + 3 compression modes.
* Feb 19, 2016: [Rebalanced compression levels](https://blog.klauspost.com/rebalancing-deflate-compression-levels/), so there is a more even progression in terms of compression. New default level is 5.
* Feb 14, 2016: Snappy: Merge upstream changes.
* Feb 14, 2016: Snappy: Fix aggressive skipping.
* Feb 14, 2016: Snappy: Update benchmark.
* Feb 13, 2016: Deflate: Fixed assembler problem that could lead to sub-optimal compression.
* Feb 12, 2016: Snappy: Added AMD64 SSE 4.2 optimizations to matching, which makes easy to compress material run faster. Typical speedup is around 25%.
* Feb 9, 2016: Added Snappy package fork. This version is 5-7% faster, much more on hard to compress content.
* Jan 30, 2016: Optimize level 1 to 3 by not considering static dictionary or storing uncompressed. ~4-5% speedup.
* Jan 16, 2016: Optimization on deflate level 1,2,3 compression.
* Jan 8 2016: Merge [CL 18317](https://go-review.googlesource.com/#/c/18317): fix reading, writing of zip64 archives.
* Dec 8 2015: Make level 1 and -2 deterministic even if write size differs.
* Dec 8 2015: Split encoding functions, so hashing and matching can potentially be inlined. 1-3% faster on AMD64. 5% faster on other platforms.
* Dec 8 2015: Fixed rare [one byte out-of bounds read](https://github.com/klauspost/compress/issues/20). Please update!
* Nov 23 2015: Optimization on token writer. ~2-4% faster. Contributed by [@dsnet](https://github.com/dsnet).
* Nov 20 2015: Small optimization to bit writer on 64 bit systems.
* Nov 17 2015: Fixed out-of-bound errors if the underlying Writer returned an error. See [#15](https://github.com/klauspost/compress/issues/15).
* Nov 12 2015: Added [io.WriterTo](https://golang.org/pkg/io/#WriterTo) support to gzip/inflate.
* Nov 11 2015: Merged [CL 16669](https://go-review.googlesource.com/#/c/16669/4): archive/zip: enable overriding (de)compressors per file
* Oct 15 2015: Added skipping on uncompressible data. Random data speed up >5x.
</details>
# deflate usage
The packages are drop-in replacements for standard library [deflate](https://godoc.org/github.com/klauspost/compress/flate), [gzip](https://godoc.org/github.com/klauspost/compress/gzip), [zip](https://godoc.org/github.com/klauspost/compress/zip), and [zlib](https://godoc.org/github.com/klauspost/compress/zlib). Simply replace the import path to use them:
Typical speed is about 2x of the standard library packages.
| old import | new import | Documentation |
|------------------|---------------------------------------|-------------------------------------------------------------------------|
| `compress/gzip` | `github.com/klauspost/compress/gzip` | [gzip](https://pkg.go.dev/github.com/klauspost/compress/gzip?tab=doc) |
| `compress/zlib` | `github.com/klauspost/compress/zlib` | [zlib](https://pkg.go.dev/github.com/klauspost/compress/zlib?tab=doc) |
| `archive/zip` | `github.com/klauspost/compress/zip` | [zip](https://pkg.go.dev/github.com/klauspost/compress/zip?tab=doc) |
| `compress/flate` | `github.com/klauspost/compress/flate` | [flate](https://pkg.go.dev/github.com/klauspost/compress/flate?tab=doc) |
You may also be interested in [pgzip](https://github.com/klauspost/pgzip), which is a drop-in replacement for gzip, which support multithreaded compression on big files and the optimized [crc32](https://github.com/klauspost/crc32) package used by these packages.
The packages implement the same API as the standard library, so you can use the original godoc documentation: [gzip](http://golang.org/pkg/compress/gzip/), [zip](http://golang.org/pkg/archive/zip/), [zlib](http://golang.org/pkg/compress/zlib/), [flate](http://golang.org/pkg/compress/flate/).
Currently there is only minor speedup on decompression (mostly CRC32 calculation).
Memory usage is typically 1MB for a Writer. stdlib is in the same range.
If you expect to have a lot of concurrently allocated Writers consider using
the stateless compression described below.
For compression performance, see: [this spreadsheet](https://docs.google.com/spreadsheets/d/1nuNE2nPfuINCZJRMt6wFWhKpToF95I47XjSsc-1rbPQ/edit?usp=sharing).
To disable all assembly add `-tags=noasm`. This works across all packages.
# Stateless compression
This package offers stateless compression as a special option for gzip/deflate.
It will do compression but without maintaining any state between Write calls.
This means there will be no memory kept between Write calls, but compression and speed will be suboptimal.
This is only relevant in cases where you expect to run many thousands of compressors concurrently,
but with very little activity. This is *not* intended for regular web servers serving individual requests.
Because of this, the size of actual Write calls will affect output size.
In gzip, specify level `-3` / `gzip.StatelessCompression` to enable.
For direct deflate use, NewStatelessWriter and StatelessDeflate are available. See [documentation](https://godoc.org/github.com/klauspost/compress/flate#NewStatelessWriter)
A `bufio.Writer` can of course be used to control write sizes. For example, to use a 4KB buffer:
```go
// replace 'ioutil.Discard' with your output.
gzw, err := gzip.NewWriterLevel(ioutil.Discard, gzip.StatelessCompression)
if err != nil {
return err
}
defer gzw.Close()
w := bufio.NewWriterSize(gzw, 4096)
defer w.Flush()
// Write to 'w'
```
This will only use up to 4KB in memory when the writer is idle.
Compression is almost always worse than the fastest compression level
and each write will allocate (a little) memory.
# Other packages
Here are other packages of good quality and pure Go (no cgo wrappers or autoconverted code):
* [github.com/pierrec/lz4](https://github.com/pierrec/lz4) - strong multithreaded LZ4 compression.
* [github.com/cosnicolaou/pbzip2](https://github.com/cosnicolaou/pbzip2) - multithreaded bzip2 decompression.
* [github.com/dsnet/compress](https://github.com/dsnet/compress) - brotli decompression, bzip2 writer.
* [github.com/ronanh/intcomp](https://github.com/ronanh/intcomp) - Integer compression.
* [github.com/spenczar/fpc](https://github.com/spenczar/fpc) - Float compression.
* [github.com/minio/zipindex](https://github.com/minio/zipindex) - External ZIP directory index.
* [github.com/ybirader/pzip](https://github.com/ybirader/pzip) - Fast concurrent zip archiver and extractor.
# license
This code is licensed under the same conditions as the original Go code. See LICENSE file.
Server/vendor/github.com/klauspost/compress/SECURITY.md
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# Security Policy
## Supported Versions
Security updates are applied only to the latest release.
## Vulnerability Definition
A security vulnerability is a bug that with certain input triggers a crash or an infinite loop. Most calls will have varying execution time and only in rare cases will slow operation be considered a security vulnerability.
Corrupted output generally is not considered a security vulnerability, unless independent operations are able to affect each other. Note that not all functionality is re-entrant and safe to use concurrently.
Out-of-memory crashes only applies if the en/decoder uses an abnormal amount of memory, with appropriate options applied, to limit maximum window size, concurrency, etc. However, if you are in doubt you are welcome to file a security issue.
It is assumed that all callers are trusted, meaning internal data exposed through reflection or inspection of returned data structures is not considered a vulnerability.
Vulnerabilities resulting from compiler/assembler errors should be reported upstream. Depending on the severity this package may or may not implement a workaround.
## Reporting a Vulnerability
If you have discovered a security vulnerability in this project, please report it privately. **Do not disclose it as a public issue.** This gives us time to work with you to fix the issue before public exposure, reducing the chance that the exploit will be used before a patch is released.
Please disclose it at [security advisory](https://github.com/klauspost/compress/security/advisories/new). If possible please provide a minimal reproducer. If the issue only applies to a single platform, it would be helpful to provide access to that.
This project is maintained by a team of volunteers on a reasonable-effort basis. As such, vulnerabilities will be disclosed in a best effort base.
Server/vendor/github.com/klauspost/compress/compressible.go
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package compress
import "math"
// Estimate returns a normalized compressibility estimate of block b.
// Values close to zero are likely uncompressible.
// Values above 0.1 are likely to be compressible.
// Values above 0.5 are very compressible.
// Very small lengths will return 0.
func Estimate(b []byte) float64 {
if len(b) < 16 {
return 0
}
// Correctly predicted order 1
hits := 0
lastMatch := false
var o1 [256]byte
var hist [256]int
c1 := byte(0)
for _, c := range b {
if c == o1[c1] {
// We only count a hit if there was two correct predictions in a row.
if lastMatch {
hits++
}
lastMatch = true
} else {
lastMatch = false
}
o1[c1] = c
c1 = c
hist[c]++
}
// Use x^0.6 to give better spread
prediction := math.Pow(float64(hits)/float64(len(b)), 0.6)
// Calculate histogram distribution
variance := float64(0)
avg := float64(len(b)) / 256
for _, v := range hist {
Δ := float64(v) - avg
variance += Δ * Δ
}
stddev := math.Sqrt(float64(variance)) / float64(len(b))
exp := math.Sqrt(1 / float64(len(b)))
// Subtract expected stddev
stddev -= exp
if stddev < 0 {
stddev = 0
}
stddev *= 1 + exp
// Use x^0.4 to give better spread
entropy := math.Pow(stddev, 0.4)
// 50/50 weight between prediction and histogram distribution
return math.Pow((prediction+entropy)/2, 0.9)
}
// ShannonEntropyBits returns the number of bits minimum required to represent
// an entropy encoding of the input bytes.
// https://en.wiktionary.org/wiki/Shannon_entropy
func ShannonEntropyBits(b []byte) int {
if len(b) == 0 {
return 0
}
var hist [256]int
for _, c := range b {
hist[c]++
}
shannon := float64(0)
invTotal := 1.0 / float64(len(b))
for _, v := range hist[:] {
if v > 0 {
n := float64(v)
shannon += math.Ceil(-math.Log2(n*invTotal) * n)
}
}
return int(math.Ceil(shannon))
}
Server/vendor/github.com/klauspost/compress/flate/deflate.go
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// Copyright 2009 The Go Authors. All rights reserved.
// Copyright (c) 2015 Klaus Post
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
import (
"errors"
"fmt"
"io"
"math"
"github.com/klauspost/compress/internal/le"
)
const (
NoCompression = 0
BestSpeed = 1
BestCompression = 9
DefaultCompression = -1
// HuffmanOnly disables Lempel-Ziv match searching and only performs Huffman
// entropy encoding. This mode is useful in compressing data that has
// already been compressed with an LZ style algorithm (e.g. Snappy or LZ4)
// that lacks an entropy encoder. Compression gains are achieved when
// certain bytes in the input stream occur more frequently than others.
//
// Note that HuffmanOnly produces a compressed output that is
// RFC 1951 compliant. That is, any valid DEFLATE decompressor will
// continue to be able to decompress this output.
HuffmanOnly = -2
ConstantCompression = HuffmanOnly // compatibility alias.
logWindowSize = 15
windowSize = 1 << logWindowSize
windowMask = windowSize - 1
logMaxOffsetSize = 15 // Standard DEFLATE
minMatchLength = 4 // The smallest match that the compressor looks for
maxMatchLength = 258 // The longest match for the compressor
minOffsetSize = 1 // The shortest offset that makes any sense
// The maximum number of tokens we will encode at the time.
// Smaller sizes usually creates less optimal blocks.
// Bigger can make context switching slow.
// We use this for levels 7-9, so we make it big.
maxFlateBlockTokens = 1 << 15
maxStoreBlockSize = 65535
hashBits = 17 // After 17 performance degrades
hashSize = 1 << hashBits
hashMask = (1 << hashBits) - 1
hashShift = (hashBits + minMatchLength - 1) / minMatchLength
maxHashOffset = 1 << 28
skipNever = math.MaxInt32
debugDeflate = false
)
type compressionLevel struct {
good, lazy, nice, chain, fastSkipHashing, level int
}
// Compression levels have been rebalanced from zlib deflate defaults
// to give a bigger spread in speed and compression.
// See https://blog.klauspost.com/rebalancing-deflate-compression-levels/
var levels = []compressionLevel{
{}, // 0
// Level 1-6 uses specialized algorithm - values not used
{0, 0, 0, 0, 0, 1},
{0, 0, 0, 0, 0, 2},
{0, 0, 0, 0, 0, 3},
{0, 0, 0, 0, 0, 4},
{0, 0, 0, 0, 0, 5},
{0, 0, 0, 0, 0, 6},
// Levels 7-9 use increasingly more lazy matching
// and increasingly stringent conditions for "good enough".
{8, 12, 16, 24, skipNever, 7},
{16, 30, 40, 64, skipNever, 8},
{32, 258, 258, 1024, skipNever, 9},
}
// advancedState contains state for the advanced levels, with bigger hash tables, etc.
type advancedState struct {
// deflate state
length int
offset int
maxInsertIndex int
chainHead int
hashOffset int
ii uint16 // position of last match, intended to overflow to reset.
// input window: unprocessed data is window[index:windowEnd]
index int
hashMatch [maxMatchLength + minMatchLength]uint32
// Input hash chains
// hashHead[hashValue] contains the largest inputIndex with the specified hash value
// If hashHead[hashValue] is within the current window, then
// hashPrev[hashHead[hashValue] & windowMask] contains the previous index
// with the same hash value.
hashHead [hashSize]uint32
hashPrev [windowSize]uint32
}
type compressor struct {
compressionLevel
h *huffmanEncoder
w *huffmanBitWriter
// compression algorithm
fill func(*compressor, []byte) int // copy data to window
step func(*compressor) // process window
window []byte
windowEnd int
blockStart int // window index where current tokens start
err error
// queued output tokens
tokens tokens
fast fastEnc
state *advancedState
sync bool // requesting flush
byteAvailable bool // if true, still need to process window[index-1].
}
func (d *compressor) fillDeflate(b []byte) int {
s := d.state
if s.index >= 2*windowSize-(minMatchLength+maxMatchLength) {
// shift the window by windowSize
//copy(d.window[:], d.window[windowSize:2*windowSize])
*(*[windowSize]byte)(d.window) = *(*[windowSize]byte)(d.window[windowSize:])
s.index -= windowSize
d.windowEnd -= windowSize
if d.blockStart >= windowSize {
d.blockStart -= windowSize
} else {
d.blockStart = math.MaxInt32
}
s.hashOffset += windowSize
if s.hashOffset > maxHashOffset {
delta := s.hashOffset - 1
s.hashOffset -= delta
s.chainHead -= delta
// Iterate over slices instead of arrays to avoid copying
// the entire table onto the stack (Issue #18625).
for i, v := range s.hashPrev[:] {
if int(v) > delta {
s.hashPrev[i] = uint32(int(v) - delta)
} else {
s.hashPrev[i] = 0
}
}
for i, v := range s.hashHead[:] {
if int(v) > delta {
s.hashHead[i] = uint32(int(v) - delta)
} else {
s.hashHead[i] = 0
}
}
}
}
n := copy(d.window[d.windowEnd:], b)
d.windowEnd += n
return n
}
func (d *compressor) writeBlock(tok *tokens, index int, eof bool) error {
if index > 0 || eof {
var window []byte
if d.blockStart <= index {
window = d.window[d.blockStart:index]
}
d.blockStart = index
//d.w.writeBlock(tok, eof, window)
d.w.writeBlockDynamic(tok, eof, window, d.sync)
return d.w.err
}
return nil
}
// writeBlockSkip writes the current block and uses the number of tokens
// to determine if the block should be stored on no matches, or
// only huffman encoded.
func (d *compressor) writeBlockSkip(tok *tokens, index int, eof bool) error {
if index > 0 || eof {
if d.blockStart <= index {
window := d.window[d.blockStart:index]
// If we removed less than a 64th of all literals
// we huffman compress the block.
if int(tok.n) > len(window)-int(tok.n>>6) {
d.w.writeBlockHuff(eof, window, d.sync)
} else {
// Write a dynamic huffman block.
d.w.writeBlockDynamic(tok, eof, window, d.sync)
}
} else {
d.w.writeBlock(tok, eof, nil)
}
d.blockStart = index
return d.w.err
}
return nil
}
// fillWindow will fill the current window with the supplied
// dictionary and calculate all hashes.
// This is much faster than doing a full encode.
// Should only be used after a start/reset.
func (d *compressor) fillWindow(b []byte) {
// Do not fill window if we are in store-only or huffman mode.
if d.level <= 0 && d.level > -MinCustomWindowSize {
return
}
if d.fast != nil {
// encode the last data, but discard the result
if len(b) > maxMatchOffset {
b = b[len(b)-maxMatchOffset:]
}
d.fast.Encode(&d.tokens, b)
d.tokens.Reset()
return
}
s := d.state
// If we are given too much, cut it.
if len(b) > windowSize {
b = b[len(b)-windowSize:]
}
// Add all to window.
n := copy(d.window[d.windowEnd:], b)
// Calculate 256 hashes at the time (more L1 cache hits)
loops := (n + 256 - minMatchLength) / 256
for j := range loops {
startindex := j * 256
end := min(startindex+256+minMatchLength-1, n)
tocheck := d.window[startindex:end]
dstSize := len(tocheck) - minMatchLength + 1
if dstSize <= 0 {
continue
}
dst := s.hashMatch[:dstSize]
bulkHash4(tocheck, dst)
var newH uint32
for i, val := range dst {
di := i + startindex
newH = val & hashMask
// Get previous value with the same hash.
// Our chain should point to the previous value.
s.hashPrev[di&windowMask] = s.hashHead[newH]
// Set the head of the hash chain to us.
s.hashHead[newH] = uint32(di + s.hashOffset)
}
}
// Update window information.
d.windowEnd += n
s.index = n
}
// Try to find a match starting at index whose length is greater than prevSize.
// We only look at chainCount possibilities before giving up.
// pos = s.index, prevHead = s.chainHead-s.hashOffset, prevLength=minMatchLength-1, lookahead
func (d *compressor) findMatch(pos int, prevHead int, lookahead int) (length, offset int, ok bool) {
minMatchLook := min(lookahead, maxMatchLength)
win := d.window[0 : pos+minMatchLook]
// We quit when we get a match that's at least nice long
nice := min(d.nice, len(win)-pos)
// If we've got a match that's good enough, only look in 1/4 the chain.
tries := d.chain
length = minMatchLength - 1
wEnd := win[pos+length]
wPos := win[pos:]
minIndex := max(pos-windowSize, 0)
offset = 0
if d.chain < 100 {
for i := prevHead; tries > 0; tries-- {
if wEnd == win[i+length] {
n := matchLen(win[i:i+minMatchLook], wPos)
if n > length {
length = n
offset = pos - i
ok = true
if n >= nice {
// The match is good enough that we don't try to find a better one.
break
}
wEnd = win[pos+n]
}
}
if i <= minIndex {
// hashPrev[i & windowMask] has already been overwritten, so stop now.
break
}
i = int(d.state.hashPrev[i&windowMask]) - d.state.hashOffset
if i < minIndex {
break
}
}
return
}
// Minimum gain to accept a match.
cGain := 4
// Some like it higher (CSV), some like it lower (JSON)
const baseCost = 3
// Base is 4 bytes at with an additional cost.
// Matches must be better than this.
for i := prevHead; tries > 0; tries-- {
if wEnd == win[i+length] {
n := matchLen(win[i:i+minMatchLook], wPos)
if n > length {
// Calculate gain. Estimate
newGain := d.h.bitLengthRaw(wPos[:n]) - int(offsetExtraBits[offsetCode(uint32(pos-i))]) - baseCost - int(lengthExtraBits[lengthCodes[(n-3)&255]])
//fmt.Println("gain:", newGain, "prev:", cGain, "raw:", d.h.bitLengthRaw(wPos[:n]), "this-len:", n, "prev-len:", length)
if newGain > cGain {
length = n
offset = pos - i
cGain = newGain
ok = true
if n >= nice {
// The match is good enough that we don't try to find a better one.
break
}
wEnd = win[pos+n]
}
}
}
if i <= minIndex {
// hashPrev[i & windowMask] has already been overwritten, so stop now.
break
}
i = int(d.state.hashPrev[i&windowMask]) - d.state.hashOffset
if i < minIndex {
break
}
}
return
}
func (d *compressor) writeStoredBlock(buf []byte) error {
if d.w.writeStoredHeader(len(buf), false); d.w.err != nil {
return d.w.err
}
d.w.writeBytes(buf)
return d.w.err
}
// hash4 returns a hash representation of the first 4 bytes
// of the supplied slice.
// The caller must ensure that len(b) >= 4.
func hash4(b []byte) uint32 {
return hash4u(le.Load32(b, 0), hashBits)
}
// hash4 returns the hash of u to fit in a hash table with h bits.
// Preferably h should be a constant and should always be <32.
func hash4u(u uint32, h uint8) uint32 {
return (u * prime4bytes) >> (32 - h)
}
// bulkHash4 will compute hashes using the same
// algorithm as hash4
func bulkHash4(b []byte, dst []uint32) {
if len(b) < 4 {
return
}
hb := le.Load32(b, 0)
dst[0] = hash4u(hb, hashBits)
end := len(b) - 4 + 1
for i := 1; i < end; i++ {
hb = (hb >> 8) | uint32(b[i+3])<<24
dst[i] = hash4u(hb, hashBits)
}
}
func (d *compressor) initDeflate() {
d.window = make([]byte, 2*windowSize)
d.byteAvailable = false
d.err = nil
if d.state == nil {
return
}
s := d.state
s.index = 0
s.hashOffset = 1
s.length = minMatchLength - 1
s.offset = 0
s.chainHead = -1
}
// deflateLazy is the same as deflate, but with d.fastSkipHashing == skipNever,
// meaning it always has lazy matching on.
func (d *compressor) deflateLazy() {
s := d.state
// Sanity enables additional runtime tests.
// It's intended to be used during development
// to supplement the currently ad-hoc unit tests.
const sanity = debugDeflate
if d.windowEnd-s.index < minMatchLength+maxMatchLength && !d.sync {
return
}
if d.windowEnd != s.index && d.chain > 100 {
// Get literal huffman coder.
if d.h == nil {
d.h = newHuffmanEncoder(maxFlateBlockTokens)
}
var tmp [256]uint16
toIndex := d.window[s.index:d.windowEnd]
toIndex = toIndex[:min(len(toIndex), maxFlateBlockTokens)]
for _, v := range toIndex {
tmp[v]++
}
d.h.generate(tmp[:], 15)
}
s.maxInsertIndex = d.windowEnd - (minMatchLength - 1)
for {
if sanity && s.index > d.windowEnd {
panic("index > windowEnd")
}
lookahead := d.windowEnd - s.index
if lookahead < minMatchLength+maxMatchLength {
if !d.sync {
return
}
if sanity && s.index > d.windowEnd {
panic("index > windowEnd")
}
if lookahead == 0 {
// Flush current output block if any.
if d.byteAvailable {
// There is still one pending token that needs to be flushed
d.tokens.AddLiteral(d.window[s.index-1])
d.byteAvailable = false
}
if d.tokens.n > 0 {
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
return
}
}
if s.index < s.maxInsertIndex {
// Update the hash
hash := hash4(d.window[s.index:])
ch := s.hashHead[hash]
s.chainHead = int(ch)
s.hashPrev[s.index&windowMask] = ch
s.hashHead[hash] = uint32(s.index + s.hashOffset)
}
prevLength := s.length
prevOffset := s.offset
s.length = minMatchLength - 1
s.offset = 0
minIndex := max(s.index-windowSize, 0)
if s.chainHead-s.hashOffset >= minIndex && lookahead > prevLength && prevLength < d.lazy {
if newLength, newOffset, ok := d.findMatch(s.index, s.chainHead-s.hashOffset, lookahead); ok {
s.length = newLength
s.offset = newOffset
}
}
if prevLength >= minMatchLength && s.length <= prevLength {
// No better match, but check for better match at end...
//
// Skip forward a number of bytes.
// Offset of 2 seems to yield best results. 3 is sometimes better.
const checkOff = 2
// Check all, except full length
if prevLength < maxMatchLength-checkOff {
prevIndex := s.index - 1
if prevIndex+prevLength < s.maxInsertIndex {
end := min(lookahead, maxMatchLength+checkOff)
end += prevIndex
// Hash at match end.
h := hash4(d.window[prevIndex+prevLength:])
ch2 := int(s.hashHead[h]) - s.hashOffset - prevLength
if prevIndex-ch2 != prevOffset && ch2 > minIndex+checkOff {
length := matchLen(d.window[prevIndex+checkOff:end], d.window[ch2+checkOff:])
// It seems like a pure length metric is best.
if length > prevLength {
prevLength = length
prevOffset = prevIndex - ch2
// Extend back...
for i := checkOff - 1; i >= 0; i-- {
if prevLength >= maxMatchLength || d.window[prevIndex+i] != d.window[ch2+i] {
// Emit tokens we "owe"
for j := 0; j <= i; j++ {
d.tokens.AddLiteral(d.window[prevIndex+j])
if d.tokens.n == maxFlateBlockTokens {
// The block includes the current character
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
s.index++
if s.index < s.maxInsertIndex {
h := hash4(d.window[s.index:])
ch := s.hashHead[h]
s.chainHead = int(ch)
s.hashPrev[s.index&windowMask] = ch
s.hashHead[h] = uint32(s.index + s.hashOffset)
}
}
break
} else {
prevLength++
}
}
} else if false {
// Check one further ahead.
// Only rarely better, disabled for now.
prevIndex++
h := hash4(d.window[prevIndex+prevLength:])
ch2 := int(s.hashHead[h]) - s.hashOffset - prevLength
if prevIndex-ch2 != prevOffset && ch2 > minIndex+checkOff {
length := matchLen(d.window[prevIndex+checkOff:end], d.window[ch2+checkOff:])
// It seems like a pure length metric is best.
if length > prevLength+checkOff {
prevLength = length
prevOffset = prevIndex - ch2
prevIndex--
// Extend back...
for i := checkOff; i >= 0; i-- {
if prevLength >= maxMatchLength || d.window[prevIndex+i] != d.window[ch2+i-1] {
// Emit tokens we "owe"
for j := 0; j <= i; j++ {
d.tokens.AddLiteral(d.window[prevIndex+j])
if d.tokens.n == maxFlateBlockTokens {
// The block includes the current character
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
s.index++
if s.index < s.maxInsertIndex {
h := hash4(d.window[s.index:])
ch := s.hashHead[h]
s.chainHead = int(ch)
s.hashPrev[s.index&windowMask] = ch
s.hashHead[h] = uint32(s.index + s.hashOffset)
}
}
break
} else {
prevLength++
}
}
}
}
}
}
}
}
// There was a match at the previous step, and the current match is
// not better. Output the previous match.
d.tokens.AddMatch(uint32(prevLength-3), uint32(prevOffset-minOffsetSize))
// Insert in the hash table all strings up to the end of the match.
// index and index-1 are already inserted. If there is not enough
// lookahead, the last two strings are not inserted into the hash
// table.
newIndex := s.index + prevLength - 1
// Calculate missing hashes
end := min(newIndex, s.maxInsertIndex)
end += minMatchLength - 1
startindex := min(s.index+1, s.maxInsertIndex)
tocheck := d.window[startindex:end]
dstSize := len(tocheck) - minMatchLength + 1
if dstSize > 0 {
dst := s.hashMatch[:dstSize]
bulkHash4(tocheck, dst)
var newH uint32
for i, val := range dst {
di := i + startindex
newH = val & hashMask
// Get previous value with the same hash.
// Our chain should point to the previous value.
s.hashPrev[di&windowMask] = s.hashHead[newH]
// Set the head of the hash chain to us.
s.hashHead[newH] = uint32(di + s.hashOffset)
}
}
s.index = newIndex
d.byteAvailable = false
s.length = minMatchLength - 1
if d.tokens.n == maxFlateBlockTokens {
// The block includes the current character
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
s.ii = 0
} else {
// Reset, if we got a match this run.
if s.length >= minMatchLength {
s.ii = 0
}
// We have a byte waiting. Emit it.
if d.byteAvailable {
s.ii++
d.tokens.AddLiteral(d.window[s.index-1])
if d.tokens.n == maxFlateBlockTokens {
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
s.index++
// If we have a long run of no matches, skip additional bytes
// Resets when s.ii overflows after 64KB.
if n := int(s.ii) - d.chain; n > 0 {
n = 1 + int(n>>6)
for j := 0; j < n; j++ {
if s.index >= d.windowEnd-1 {
break
}
d.tokens.AddLiteral(d.window[s.index-1])
if d.tokens.n == maxFlateBlockTokens {
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
// Index...
if s.index < s.maxInsertIndex {
h := hash4(d.window[s.index:])
ch := s.hashHead[h]
s.chainHead = int(ch)
s.hashPrev[s.index&windowMask] = ch
s.hashHead[h] = uint32(s.index + s.hashOffset)
}
s.index++
}
// Flush last byte
d.tokens.AddLiteral(d.window[s.index-1])
d.byteAvailable = false
// s.length = minMatchLength - 1 // not needed, since s.ii is reset above, so it should never be > minMatchLength
if d.tokens.n == maxFlateBlockTokens {
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
}
} else {
s.index++
d.byteAvailable = true
}
}
}
}
func (d *compressor) store() {
if d.windowEnd > 0 && (d.windowEnd == maxStoreBlockSize || d.sync) {
d.err = d.writeStoredBlock(d.window[:d.windowEnd])
d.windowEnd = 0
}
}
// fillWindow will fill the buffer with data for huffman-only compression.
// The number of bytes copied is returned.
func (d *compressor) fillBlock(b []byte) int {
n := copy(d.window[d.windowEnd:], b)
d.windowEnd += n
return n
}
// storeHuff will compress and store the currently added data,
// if enough has been accumulated or we at the end of the stream.
// Any error that occurred will be in d.err
func (d *compressor) storeHuff() {
if d.windowEnd < len(d.window) && !d.sync || d.windowEnd == 0 {
return
}
d.w.writeBlockHuff(false, d.window[:d.windowEnd], d.sync)
d.err = d.w.err
d.windowEnd = 0
}
// storeFast will compress and store the currently added data,
// if enough has been accumulated or we at the end of the stream.
// Any error that occurred will be in d.err
func (d *compressor) storeFast() {
// We only compress if we have maxStoreBlockSize.
if d.windowEnd < len(d.window) {
if !d.sync {
return
}
// Handle extremely small sizes.
if d.windowEnd < 128 {
if d.windowEnd == 0 {
return
}
if d.windowEnd <= 32 {
d.err = d.writeStoredBlock(d.window[:d.windowEnd])
} else {
d.w.writeBlockHuff(false, d.window[:d.windowEnd], true)
d.err = d.w.err
}
d.tokens.Reset()
d.windowEnd = 0
d.fast.Reset()
return
}
}
d.fast.Encode(&d.tokens, d.window[:d.windowEnd])
// If we made zero matches, store the block as is.
if d.tokens.n == 0 {
d.err = d.writeStoredBlock(d.window[:d.windowEnd])
// If we removed less than 1/16th, huffman compress the block.
} else if int(d.tokens.n) > d.windowEnd-(d.windowEnd>>4) {
d.w.writeBlockHuff(false, d.window[:d.windowEnd], d.sync)
d.err = d.w.err
} else {
d.w.writeBlockDynamic(&d.tokens, false, d.window[:d.windowEnd], d.sync)
d.err = d.w.err
}
d.tokens.Reset()
d.windowEnd = 0
}
// write will add input byte to the stream.
// Unless an error occurs all bytes will be consumed.
func (d *compressor) write(b []byte) (n int, err error) {
if d.err != nil {
return 0, d.err
}
n = len(b)
for len(b) > 0 {
if d.windowEnd == len(d.window) || d.sync {
d.step(d)
}
b = b[d.fill(d, b):]
if d.err != nil {
return 0, d.err
}
}
return n, d.err
}
func (d *compressor) syncFlush() error {
d.sync = true
if d.err != nil {
return d.err
}
d.step(d)
if d.err == nil {
d.w.writeStoredHeader(0, false)
d.w.flush()
d.err = d.w.err
}
d.sync = false
return d.err
}
func (d *compressor) init(w io.Writer, level int) (err error) {
d.w = newHuffmanBitWriter(w)
switch {
case level == NoCompression:
d.window = make([]byte, maxStoreBlockSize)
d.fill = (*compressor).fillBlock
d.step = (*compressor).store
case level == ConstantCompression:
d.w.logNewTablePenalty = 10
d.window = make([]byte, 32<<10)
d.fill = (*compressor).fillBlock
d.step = (*compressor).storeHuff
case level == DefaultCompression:
level = 5
fallthrough
case level >= 1 && level <= 6:
d.w.logNewTablePenalty = 7
d.fast = newFastEnc(level)
d.window = make([]byte, maxStoreBlockSize)
d.fill = (*compressor).fillBlock
d.step = (*compressor).storeFast
case 7 <= level && level <= 9:
d.w.logNewTablePenalty = 8
d.state = &advancedState{}
d.compressionLevel = levels[level]
d.initDeflate()
d.fill = (*compressor).fillDeflate
d.step = (*compressor).deflateLazy
case -level >= MinCustomWindowSize && -level <= MaxCustomWindowSize:
d.w.logNewTablePenalty = 7
d.fast = &fastEncL5Window{maxOffset: int32(-level), cur: maxStoreBlockSize}
d.window = make([]byte, maxStoreBlockSize)
d.fill = (*compressor).fillBlock
d.step = (*compressor).storeFast
default:
return fmt.Errorf("flate: invalid compression level %d: want value in range [-2, 9]", level)
}
d.level = level
return nil
}
// reset the state of the compressor.
func (d *compressor) reset(w io.Writer) {
d.w.reset(w)
d.sync = false
d.err = nil
// We only need to reset a few things for Snappy.
if d.fast != nil {
d.fast.Reset()
d.windowEnd = 0
d.tokens.Reset()
return
}
switch d.compressionLevel.chain {
case 0:
// level was NoCompression or ConstantCompression.
d.windowEnd = 0
default:
s := d.state
s.chainHead = -1
for i := range s.hashHead {
s.hashHead[i] = 0
}
for i := range s.hashPrev {
s.hashPrev[i] = 0
}
s.hashOffset = 1
s.index, d.windowEnd = 0, 0
d.blockStart, d.byteAvailable = 0, false
d.tokens.Reset()
s.length = minMatchLength - 1
s.offset = 0
s.ii = 0
s.maxInsertIndex = 0
}
}
func (d *compressor) close() error {
if d.err != nil {
return d.err
}
d.sync = true
d.step(d)
if d.err != nil {
return d.err
}
if d.w.writeStoredHeader(0, true); d.w.err != nil {
return d.w.err
}
d.w.flush()
d.w.reset(nil)
return d.w.err
}
// NewWriter returns a new Writer compressing data at the given level.
// Following zlib, levels range from 1 (BestSpeed) to 9 (BestCompression);
// higher levels typically run slower but compress more.
// Level 0 (NoCompression) does not attempt any compression; it only adds the
// necessary DEFLATE framing.
// Level -1 (DefaultCompression) uses the default compression level.
// Level -2 (ConstantCompression) will use Huffman compression only, giving
// a very fast compression for all types of input, but sacrificing considerable
// compression efficiency.
//
// If level is in the range [-2, 9] then the error returned will be nil.
// Otherwise the error returned will be non-nil.
func NewWriter(w io.Writer, level int) (*Writer, error) {
var dw Writer
if err := dw.d.init(w, level); err != nil {
return nil, err
}
return &dw, nil
}
// NewWriterDict is like NewWriter but initializes the new
// Writer with a preset dictionary. The returned Writer behaves
// as if the dictionary had been written to it without producing
// any compressed output. The compressed data written to w
// can only be decompressed by a Reader initialized with the
// same dictionary.
func NewWriterDict(w io.Writer, level int, dict []byte) (*Writer, error) {
zw, err := NewWriter(w, level)
if err != nil {
return nil, err
}
zw.d.fillWindow(dict)
zw.dict = append(zw.dict, dict...) // duplicate dictionary for Reset method.
return zw, err
}
// MinCustomWindowSize is the minimum window size that can be sent to NewWriterWindow.
const MinCustomWindowSize = 32
// MaxCustomWindowSize is the maximum custom window that can be sent to NewWriterWindow.
const MaxCustomWindowSize = windowSize
// NewWriterWindow returns a new Writer compressing data with a custom window size.
// windowSize must be from MinCustomWindowSize to MaxCustomWindowSize.
func NewWriterWindow(w io.Writer, windowSize int) (*Writer, error) {
if windowSize < MinCustomWindowSize {
return nil, errors.New("flate: requested window size less than MinWindowSize")
}
if windowSize > MaxCustomWindowSize {
return nil, errors.New("flate: requested window size bigger than MaxCustomWindowSize")
}
var dw Writer
if err := dw.d.init(w, -windowSize); err != nil {
return nil, err
}
return &dw, nil
}
// A Writer takes data written to it and writes the compressed
// form of that data to an underlying writer (see NewWriter).
type Writer struct {
d compressor
dict []byte
}
// Write writes data to w, which will eventually write the
// compressed form of data to its underlying writer.
func (w *Writer) Write(data []byte) (n int, err error) {
return w.d.write(data)
}
// Flush flushes any pending data to the underlying writer.
// It is useful mainly in compressed network protocols, to ensure that
// a remote reader has enough data to reconstruct a packet.
// Flush does not return until the data has been written.
// Calling Flush when there is no pending data still causes the Writer
// to emit a sync marker of at least 4 bytes.
// If the underlying writer returns an error, Flush returns that error.
//
// In the terminology of the zlib library, Flush is equivalent to Z_SYNC_FLUSH.
func (w *Writer) Flush() error {
// For more about flushing:
// http://www.bolet.org/~pornin/deflate-flush.html
return w.d.syncFlush()
}
// Close flushes and closes the writer.
func (w *Writer) Close() error {
return w.d.close()
}
// Reset discards the writer's state and makes it equivalent to
// the result of NewWriter or NewWriterDict called with dst
// and w's level and dictionary.
func (w *Writer) Reset(dst io.Writer) {
if len(w.dict) > 0 {
// w was created with NewWriterDict
w.d.reset(dst)
if dst != nil {
w.d.fillWindow(w.dict)
}
} else {
// w was created with NewWriter
w.d.reset(dst)
}
}
// ResetDict discards the writer's state and makes it equivalent to
// the result of NewWriter or NewWriterDict called with dst
// and w's level, but sets a specific dictionary.
func (w *Writer) ResetDict(dst io.Writer, dict []byte) {
w.dict = dict
w.d.reset(dst)
w.d.fillWindow(w.dict)
}
Server/vendor/github.com/klauspost/compress/flate/dict_decoder.go
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+181
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// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
// dictDecoder implements the LZ77 sliding dictionary as used in decompression.
// LZ77 decompresses data through sequences of two forms of commands:
//
// - Literal insertions: Runs of one or more symbols are inserted into the data
// stream as is. This is accomplished through the writeByte method for a
// single symbol, or combinations of writeSlice/writeMark for multiple symbols.
// Any valid stream must start with a literal insertion if no preset dictionary
// is used.
//
// - Backward copies: Runs of one or more symbols are copied from previously
// emitted data. Backward copies come as the tuple (dist, length) where dist
// determines how far back in the stream to copy from and length determines how
// many bytes to copy. Note that it is valid for the length to be greater than
// the distance. Since LZ77 uses forward copies, that situation is used to
// perform a form of run-length encoding on repeated runs of symbols.
// The writeCopy and tryWriteCopy are used to implement this command.
//
// For performance reasons, this implementation performs little to no sanity
// checks about the arguments. As such, the invariants documented for each
// method call must be respected.
type dictDecoder struct {
hist []byte // Sliding window history
// Invariant: 0 <= rdPos <= wrPos <= len(hist)
wrPos int // Current output position in buffer
rdPos int // Have emitted hist[:rdPos] already
full bool // Has a full window length been written yet?
}
// init initializes dictDecoder to have a sliding window dictionary of the given
// size. If a preset dict is provided, it will initialize the dictionary with
// the contents of dict.
func (dd *dictDecoder) init(size int, dict []byte) {
*dd = dictDecoder{hist: dd.hist}
if cap(dd.hist) < size {
dd.hist = make([]byte, size)
}
dd.hist = dd.hist[:size]
if len(dict) > len(dd.hist) {
dict = dict[len(dict)-len(dd.hist):]
}
dd.wrPos = copy(dd.hist, dict)
if dd.wrPos == len(dd.hist) {
dd.wrPos = 0
dd.full = true
}
dd.rdPos = dd.wrPos
}
// histSize reports the total amount of historical data in the dictionary.
func (dd *dictDecoder) histSize() int {
if dd.full {
return len(dd.hist)
}
return dd.wrPos
}
// availRead reports the number of bytes that can be flushed by readFlush.
func (dd *dictDecoder) availRead() int {
return dd.wrPos - dd.rdPos
}
// availWrite reports the available amount of output buffer space.
func (dd *dictDecoder) availWrite() int {
return len(dd.hist) - dd.wrPos
}
// writeSlice returns a slice of the available buffer to write data to.
//
// This invariant will be kept: len(s) <= availWrite()
func (dd *dictDecoder) writeSlice() []byte {
return dd.hist[dd.wrPos:]
}
// writeMark advances the writer pointer by cnt.
//
// This invariant must be kept: 0 <= cnt <= availWrite()
func (dd *dictDecoder) writeMark(cnt int) {
dd.wrPos += cnt
}
// writeByte writes a single byte to the dictionary.
//
// This invariant must be kept: 0 < availWrite()
func (dd *dictDecoder) writeByte(c byte) {
dd.hist[dd.wrPos] = c
dd.wrPos++
}
// writeCopy copies a string at a given (dist, length) to the output.
// This returns the number of bytes copied and may be less than the requested
// length if the available space in the output buffer is too small.
//
// This invariant must be kept: 0 < dist <= histSize()
func (dd *dictDecoder) writeCopy(dist, length int) int {
dstBase := dd.wrPos
dstPos := dstBase
srcPos := dstPos - dist
endPos := min(dstPos+length, len(dd.hist))
// Copy non-overlapping section after destination position.
//
// This section is non-overlapping in that the copy length for this section
// is always less than or equal to the backwards distance. This can occur
// if a distance refers to data that wraps-around in the buffer.
// Thus, a backwards copy is performed here; that is, the exact bytes in
// the source prior to the copy is placed in the destination.
if srcPos < 0 {
srcPos += len(dd.hist)
dstPos += copy(dd.hist[dstPos:endPos], dd.hist[srcPos:])
srcPos = 0
}
// Copy possibly overlapping section before destination position.
//
// This section can overlap if the copy length for this section is larger
// than the backwards distance. This is allowed by LZ77 so that repeated
// strings can be succinctly represented using (dist, length) pairs.
// Thus, a forwards copy is performed here; that is, the bytes copied is
// possibly dependent on the resulting bytes in the destination as the copy
// progresses along. This is functionally equivalent to the following:
//
// for i := 0; i < endPos-dstPos; i++ {
// dd.hist[dstPos+i] = dd.hist[srcPos+i]
// }
// dstPos = endPos
//
for dstPos < endPos {
dstPos += copy(dd.hist[dstPos:endPos], dd.hist[srcPos:dstPos])
}
dd.wrPos = dstPos
return dstPos - dstBase
}
// tryWriteCopy tries to copy a string at a given (distance, length) to the
// output. This specialized version is optimized for short distances.
//
// This method is designed to be inlined for performance reasons.
//
// This invariant must be kept: 0 < dist <= histSize()
func (dd *dictDecoder) tryWriteCopy(dist, length int) int {
dstPos := dd.wrPos
endPos := dstPos + length
if dstPos < dist || endPos > len(dd.hist) {
return 0
}
dstBase := dstPos
srcPos := dstPos - dist
// Copy possibly overlapping section before destination position.
loop:
dstPos += copy(dd.hist[dstPos:endPos], dd.hist[srcPos:dstPos])
if dstPos < endPos {
goto loop // Avoid for-loop so that this function can be inlined
}
dd.wrPos = dstPos
return dstPos - dstBase
}
// readFlush returns a slice of the historical buffer that is ready to be
// emitted to the user. The data returned by readFlush must be fully consumed
// before calling any other dictDecoder methods.
func (dd *dictDecoder) readFlush() []byte {
toRead := dd.hist[dd.rdPos:dd.wrPos]
dd.rdPos = dd.wrPos
if dd.wrPos == len(dd.hist) {
dd.wrPos, dd.rdPos = 0, 0
dd.full = true
}
return toRead
}
Server/vendor/github.com/klauspost/compress/flate/fast_encoder.go
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+189
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// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Modified for deflate by Klaus Post (c) 2015.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
import (
"fmt"
"github.com/klauspost/compress/internal/le"
)
type fastEnc interface {
Encode(dst *tokens, src []byte)
Reset()
}
func newFastEnc(level int) fastEnc {
switch level {
case 1:
return &fastEncL1{fastGen: fastGen{cur: maxStoreBlockSize}}
case 2:
return &fastEncL2{fastGen: fastGen{cur: maxStoreBlockSize}}
case 3:
return &fastEncL3{fastGen: fastGen{cur: maxStoreBlockSize}}
case 4:
return &fastEncL4{fastGen: fastGen{cur: maxStoreBlockSize}}
case 5:
return &fastEncL5{fastGen: fastGen{cur: maxStoreBlockSize}}
case 6:
return &fastEncL6{fastGen: fastGen{cur: maxStoreBlockSize}}
default:
panic("invalid level specified")
}
}
const (
tableBits = 15 // Bits used in the table
tableSize = 1 << tableBits // Size of the table
tableShift = 32 - tableBits // Right-shift to get the tableBits most significant bits of a uint32.
baseMatchOffset = 1 // The smallest match offset
baseMatchLength = 3 // The smallest match length per the RFC section 3.2.5
maxMatchOffset = 1 << 15 // The largest match offset
bTableBits = 17 // Bits used in the big tables
bTableSize = 1 << bTableBits // Size of the table
allocHistory = maxStoreBlockSize * 5 // Size to preallocate for history.
bufferReset = (1 << 31) - allocHistory - maxStoreBlockSize - 1 // Reset the buffer offset when reaching this.
)
const (
prime3bytes = 506832829
prime4bytes = 2654435761
prime5bytes = 889523592379
prime6bytes = 227718039650203
prime7bytes = 58295818150454627
prime8bytes = 0xcf1bbcdcb7a56463
)
func load3232(b []byte, i int32) uint32 {
return le.Load32(b, i)
}
func load6432(b []byte, i int32) uint64 {
return le.Load64(b, i)
}
type tableEntry struct {
offset int32
}
// fastGen maintains the table for matches,
// and the previous byte block for level 2.
// This is the generic implementation.
type fastGen struct {
hist []byte
cur int32
}
func (e *fastGen) addBlock(src []byte) int32 {
// check if we have space already
if len(e.hist)+len(src) > cap(e.hist) {
if cap(e.hist) == 0 {
e.hist = make([]byte, 0, allocHistory)
} else {
if cap(e.hist) < maxMatchOffset*2 {
panic("unexpected buffer size")
}
// Move down
offset := int32(len(e.hist)) - maxMatchOffset
// copy(e.hist[0:maxMatchOffset], e.hist[offset:])
*(*[maxMatchOffset]byte)(e.hist) = *(*[maxMatchOffset]byte)(e.hist[offset:])
e.cur += offset
e.hist = e.hist[:maxMatchOffset]
}
}
s := int32(len(e.hist))
e.hist = append(e.hist, src...)
return s
}
type tableEntryPrev struct {
Cur tableEntry
Prev tableEntry
}
// hash7 returns the hash of the lowest 7 bytes of u to fit in a hash table with h bits.
// Preferably h should be a constant and should always be <64.
func hash7(u uint64, h uint8) uint32 {
return uint32(((u << (64 - 56)) * prime7bytes) >> ((64 - h) & reg8SizeMask64))
}
// hashLen returns a hash of the lowest mls bytes of with length output bits.
// mls must be >=3 and <=8. Any other value will return hash for 4 bytes.
// length should always be < 32.
// Preferably length and mls should be a constant for inlining.
func hashLen(u uint64, length, mls uint8) uint32 {
switch mls {
case 3:
return (uint32(u<<8) * prime3bytes) >> (32 - length)
case 5:
return uint32(((u << (64 - 40)) * prime5bytes) >> (64 - length))
case 6:
return uint32(((u << (64 - 48)) * prime6bytes) >> (64 - length))
case 7:
return uint32(((u << (64 - 56)) * prime7bytes) >> (64 - length))
case 8:
return uint32((u * prime8bytes) >> (64 - length))
default:
return (uint32(u) * prime4bytes) >> (32 - length)
}
}
// matchlen will return the match length between offsets and t in src.
// The maximum length returned is maxMatchLength - 4.
// It is assumed that s > t, that t >=0 and s < len(src).
func (e *fastGen) matchlen(s, t int, src []byte) int32 {
if debugDeflate {
if t >= s {
panic(fmt.Sprint("t >=s:", t, s))
}
if int(s) >= len(src) {
panic(fmt.Sprint("s >= len(src):", s, len(src)))
}
if t < 0 {
panic(fmt.Sprint("t < 0:", t))
}
if s-t > maxMatchOffset {
panic(fmt.Sprint(s, "-", t, "(", s-t, ") > maxMatchLength (", maxMatchOffset, ")"))
}
}
a := src[s:min(s+maxMatchLength-4, len(src))]
b := src[t:]
return int32(matchLen(a, b))
}
// matchlenLong will return the match length between offsets and t in src.
// It is assumed that s > t, that t >=0 and s < len(src).
func (e *fastGen) matchlenLong(s, t int, src []byte) int32 {
if debugDeflate {
if t >= s {
panic(fmt.Sprint("t >=s:", t, s))
}
if int(s) >= len(src) {
panic(fmt.Sprint("s >= len(src):", s, len(src)))
}
if t < 0 {
panic(fmt.Sprint("t < 0:", t))
}
if s-t > maxMatchOffset {
panic(fmt.Sprint(s, "-", t, "(", s-t, ") > maxMatchLength (", maxMatchOffset, ")"))
}
}
return int32(matchLen(src[s:], src[t:]))
}
// Reset the encoding table.
func (e *fastGen) Reset() {
if cap(e.hist) < allocHistory {
e.hist = make([]byte, 0, allocHistory)
}
// We offset current position so everything will be out of reach.
// If we are above the buffer reset it will be cleared anyway since len(hist) == 0.
if e.cur <= bufferReset {
e.cur += maxMatchOffset + int32(len(e.hist))
}
e.hist = e.hist[:0]
}
Server/vendor/github.com/klauspost/compress/flate/huffman_bit_writer.go
Generated Vendored
+1174
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Server/vendor/github.com/klauspost/compress/flate/huffman_code.go
Generated Vendored
+417
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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
import (
"math"
"math/bits"
)
const (
maxBitsLimit = 16
// number of valid literals
literalCount = 286
)
// hcode is a huffman code with a bit code and bit length.
type hcode uint32
func (h hcode) len() uint8 {
return uint8(h)
}
func (h hcode) code64() uint64 {
return uint64(h >> 8)
}
func (h hcode) zero() bool {
return h == 0
}
type huffmanEncoder struct {
codes []hcode
bitCount [17]int32
// Allocate a reusable buffer with the longest possible frequency table.
// Possible lengths are codegenCodeCount, offsetCodeCount and literalCount.
// The largest of these is literalCount, so we allocate for that case.
freqcache [literalCount + 1]literalNode
}
type literalNode struct {
literal uint16
freq uint16
}
// A levelInfo describes the state of the constructed tree for a given depth.
type levelInfo struct {
// Our level. for better printing
level int32
// The frequency of the last node at this level
lastFreq int32
// The frequency of the next character to add to this level
nextCharFreq int32
// The frequency of the next pair (from level below) to add to this level.
// Only valid if the "needed" value of the next lower level is 0.
nextPairFreq int32
// The number of chains remaining to generate for this level before moving
// up to the next level
needed int32
}
// set sets the code and length of an hcode.
func (h *hcode) set(code uint16, length uint8) {
*h = hcode(length) | (hcode(code) << 8)
}
func newhcode(code uint16, length uint8) hcode {
return hcode(length) | (hcode(code) << 8)
}
func reverseBits(number uint16, bitLength byte) uint16 {
return bits.Reverse16(number << ((16 - bitLength) & 15))
}
func maxNode() literalNode { return literalNode{math.MaxUint16, math.MaxUint16} }
func newHuffmanEncoder(size int) *huffmanEncoder {
// Make capacity to next power of two.
c := uint(bits.Len32(uint32(size - 1)))
return &huffmanEncoder{codes: make([]hcode, size, 1<<c)}
}
// Generates a HuffmanCode corresponding to the fixed literal table
func generateFixedLiteralEncoding() *huffmanEncoder {
h := newHuffmanEncoder(literalCount)
codes := h.codes
var ch uint16
for ch = range uint16(literalCount) {
var bits uint16
var size uint8
switch {
case ch < 144:
// size 8, 000110000 .. 10111111
bits = ch + 48
size = 8
case ch < 256:
// size 9, 110010000 .. 111111111
bits = ch + 400 - 144
size = 9
case ch < 280:
// size 7, 0000000 .. 0010111
bits = ch - 256
size = 7
default:
// size 8, 11000000 .. 11000111
bits = ch + 192 - 280
size = 8
}
codes[ch] = newhcode(reverseBits(bits, size), size)
}
return h
}
func generateFixedOffsetEncoding() *huffmanEncoder {
h := newHuffmanEncoder(30)
codes := h.codes
for ch := range codes {
codes[ch] = newhcode(reverseBits(uint16(ch), 5), 5)
}
return h
}
var fixedLiteralEncoding = generateFixedLiteralEncoding()
var fixedOffsetEncoding = generateFixedOffsetEncoding()
func (h *huffmanEncoder) bitLength(freq []uint16) int {
var total int
for i, f := range freq {
if f != 0 {
total += int(f) * int(h.codes[i].len())
}
}
return total
}
func (h *huffmanEncoder) bitLengthRaw(b []byte) int {
var total int
for _, f := range b {
total += int(h.codes[f].len())
}
return total
}
// canReuseBits returns the number of bits or math.MaxInt32 if the encoder cannot be reused.
func (h *huffmanEncoder) canReuseBits(freq []uint16) int {
var total int
for i, f := range freq {
if f != 0 {
code := h.codes[i]
if code.zero() {
return math.MaxInt32
}
total += int(f) * int(code.len())
}
}
return total
}
// Return the number of literals assigned to each bit size in the Huffman encoding
//
// This method is only called when list.length >= 3
// The cases of 0, 1, and 2 literals are handled by special case code.
//
// list An array of the literals with non-zero frequencies
//
// and their associated frequencies. The array is in order of increasing
// frequency, and has as its last element a special element with frequency
// MaxInt32
//
// maxBits The maximum number of bits that should be used to encode any literal.
//
// Must be less than 16.
//
// return An integer array in which array[i] indicates the number of literals
//
// that should be encoded in i bits.
func (h *huffmanEncoder) bitCounts(list []literalNode, maxBits int32) []int32 {
if maxBits >= maxBitsLimit {
panic("flate: maxBits too large")
}
n := int32(len(list))
list = list[0 : n+1]
list[n] = maxNode()
// The tree can't have greater depth than n - 1, no matter what. This
// saves a little bit of work in some small cases
if maxBits > n-1 {
maxBits = n - 1
}
// Create information about each of the levels.
// A bogus "Level 0" whose sole purpose is so that
// level1.prev.needed==0. This makes level1.nextPairFreq
// be a legitimate value that never gets chosen.
var levels [maxBitsLimit]levelInfo
// leafCounts[i] counts the number of literals at the left
// of ancestors of the rightmost node at level i.
// leafCounts[i][j] is the number of literals at the left
// of the level j ancestor.
var leafCounts [maxBitsLimit][maxBitsLimit]int32
// Descending to only have 1 bounds check.
l2f := int32(list[2].freq)
l1f := int32(list[1].freq)
l0f := int32(list[0].freq) + int32(list[1].freq)
for level := int32(1); level <= maxBits; level++ {
// For every level, the first two items are the first two characters.
// We initialize the levels as if we had already figured this out.
levels[level] = levelInfo{
level: level,
lastFreq: l1f,
nextCharFreq: l2f,
nextPairFreq: l0f,
}
leafCounts[level][level] = 2
if level == 1 {
levels[level].nextPairFreq = math.MaxInt32
}
}
// We need a total of 2*n - 2 items at top level and have already generated 2.
levels[maxBits].needed = 2*n - 4
level := uint32(maxBits)
for level < 16 {
l := &levels[level]
if l.nextPairFreq == math.MaxInt32 && l.nextCharFreq == math.MaxInt32 {
// We've run out of both leafs and pairs.
// End all calculations for this level.
// To make sure we never come back to this level or any lower level,
// set nextPairFreq impossibly large.
l.needed = 0
levels[level+1].nextPairFreq = math.MaxInt32
level++
continue
}
prevFreq := l.lastFreq
if l.nextCharFreq < l.nextPairFreq {
// The next item on this row is a leaf node.
n := leafCounts[level][level] + 1
l.lastFreq = l.nextCharFreq
// Lower leafCounts are the same of the previous node.
leafCounts[level][level] = n
e := list[n]
if e.literal < math.MaxUint16 {
l.nextCharFreq = int32(e.freq)
} else {
l.nextCharFreq = math.MaxInt32
}
} else {
// The next item on this row is a pair from the previous row.
// nextPairFreq isn't valid until we generate two
// more values in the level below
l.lastFreq = l.nextPairFreq
// Take leaf counts from the lower level, except counts[level] remains the same.
if true {
save := leafCounts[level][level]
leafCounts[level] = leafCounts[level-1]
leafCounts[level][level] = save
} else {
copy(leafCounts[level][:level], leafCounts[level-1][:level])
}
levels[l.level-1].needed = 2
}
if l.needed--; l.needed == 0 {
// We've done everything we need to do for this level.
// Continue calculating one level up. Fill in nextPairFreq
// of that level with the sum of the two nodes we've just calculated on
// this level.
if l.level == maxBits {
// All done!
break
}
levels[l.level+1].nextPairFreq = prevFreq + l.lastFreq
level++
} else {
// If we stole from below, move down temporarily to replenish it.
for levels[level-1].needed > 0 {
level--
}
}
}
// Somethings is wrong if at the end, the top level is null or hasn't used
// all of the leaves.
if leafCounts[maxBits][maxBits] != n {
panic("leafCounts[maxBits][maxBits] != n")
}
bitCount := h.bitCount[:maxBits+1]
bits := 1
counts := &leafCounts[maxBits]
for level := maxBits; level > 0; level-- {
// chain.leafCount gives the number of literals requiring at least "bits"
// bits to encode.
bitCount[bits] = counts[level] - counts[level-1]
bits++
}
return bitCount
}
// Look at the leaves and assign them a bit count and an encoding as specified
// in RFC 1951 3.2.2
func (h *huffmanEncoder) assignEncodingAndSize(bitCount []int32, list []literalNode) {
code := uint16(0)
for n, bits := range bitCount {
code <<= 1
if n == 0 || bits == 0 {
continue
}
// The literals list[len(list)-bits] .. list[len(list)-bits]
// are encoded using "bits" bits, and get the values
// code, code + 1, .... The code values are
// assigned in literal order (not frequency order).
chunk := list[len(list)-int(bits):]
sortByLiteral(chunk)
for _, node := range chunk {
h.codes[node.literal] = newhcode(reverseBits(code, uint8(n)), uint8(n))
code++
}
list = list[0 : len(list)-int(bits)]
}
}
// Update this Huffman Code object to be the minimum code for the specified frequency count.
//
// freq An array of frequencies, in which frequency[i] gives the frequency of literal i.
// maxBits The maximum number of bits to use for any literal.
func (h *huffmanEncoder) generate(freq []uint16, maxBits int32) {
list := h.freqcache[:len(freq)+1]
codes := h.codes[:len(freq)]
// Number of non-zero literals
count := 0
// Set list to be the set of all non-zero literals and their frequencies
for i, f := range freq {
if f != 0 {
list[count] = literalNode{uint16(i), f}
count++
} else {
codes[i] = 0
}
}
list[count] = literalNode{}
list = list[:count]
if count <= 2 {
// Handle the small cases here, because they are awkward for the general case code. With
// two or fewer literals, everything has bit length 1.
for i, node := range list {
// "list" is in order of increasing literal value.
h.codes[node.literal].set(uint16(i), 1)
}
return
}
sortByFreq(list)
// Get the number of literals for each bit count
bitCount := h.bitCounts(list, maxBits)
// And do the assignment
h.assignEncodingAndSize(bitCount, list)
}
// atLeastOne clamps the result between 1 and 15.
func atLeastOne(v float32) float32 {
if v < 1 {
return 1
}
if v > 15 {
return 15
}
return v
}
func histogram(b []byte, h []uint16) {
if true && len(b) >= 8<<10 {
// Split for bigger inputs
histogramSplit(b, h)
} else {
h = h[:256]
for _, t := range b {
h[t]++
}
}
}
func histogramSplit(b []byte, h []uint16) {
// Tested, and slightly faster than 2-way.
// Writing to separate arrays and combining is also slightly slower.
h = h[:256]
for len(b)&3 != 0 {
h[b[0]]++
b = b[1:]
}
n := len(b) / 4
x, y, z, w := b[:n], b[n:], b[n+n:], b[n+n+n:]
y, z, w = y[:len(x)], z[:len(x)], w[:len(x)]
for i, t := range x {
v0 := &h[t]
v1 := &h[y[i]]
v2 := &h[z[i]]
v3 := &h[w[i]]
*v0++
*v1++
*v2++
*v3++
}
}
Server/vendor/github.com/klauspost/compress/flate/huffman_sortByFreq.go
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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
// Sort sorts data.
// It makes one call to data.Len to determine n, and O(n*log(n)) calls to
// data.Less and data.Swap. The sort is not guaranteed to be stable.
func sortByFreq(data []literalNode) {
n := len(data)
quickSortByFreq(data, 0, n, maxDepth(n))
}
func quickSortByFreq(data []literalNode, a, b, maxDepth int) {
for b-a > 12 { // Use ShellSort for slices <= 12 elements
if maxDepth == 0 {
heapSort(data, a, b)
return
}
maxDepth--
mlo, mhi := doPivotByFreq(data, a, b)
// Avoiding recursion on the larger subproblem guarantees
// a stack depth of at most lg(b-a).
if mlo-a < b-mhi {
quickSortByFreq(data, a, mlo, maxDepth)
a = mhi // i.e., quickSortByFreq(data, mhi, b)
} else {
quickSortByFreq(data, mhi, b, maxDepth)
b = mlo // i.e., quickSortByFreq(data, a, mlo)
}
}
if b-a > 1 {
// Do ShellSort pass with gap 6
// It could be written in this simplified form cause b-a <= 12
for i := a + 6; i < b; i++ {
if data[i].freq == data[i-6].freq && data[i].literal < data[i-6].literal || data[i].freq < data[i-6].freq {
data[i], data[i-6] = data[i-6], data[i]
}
}
insertionSortByFreq(data, a, b)
}
}
func doPivotByFreq(data []literalNode, lo, hi int) (midlo, midhi int) {
m := int(uint(lo+hi) >> 1) // Written like this to avoid integer overflow.
if hi-lo > 40 {
// Tukey's ``Ninther,'' median of three medians of three.
s := (hi - lo) / 8
medianOfThreeSortByFreq(data, lo, lo+s, lo+2*s)
medianOfThreeSortByFreq(data, m, m-s, m+s)
medianOfThreeSortByFreq(data, hi-1, hi-1-s, hi-1-2*s)
}
medianOfThreeSortByFreq(data, lo, m, hi-1)
// Invariants are:
// data[lo] = pivot (set up by ChoosePivot)
// data[lo < i < a] < pivot
// data[a <= i < b] <= pivot
// data[b <= i < c] unexamined
// data[c <= i < hi-1] > pivot
// data[hi-1] >= pivot
pivot := lo
a, c := lo+1, hi-1
for ; a < c && (data[a].freq == data[pivot].freq && data[a].literal < data[pivot].literal || data[a].freq < data[pivot].freq); a++ {
}
b := a
for {
for ; b < c && (data[pivot].freq == data[b].freq && data[pivot].literal > data[b].literal || data[pivot].freq > data[b].freq); b++ { // data[b] <= pivot
}
for ; b < c && (data[pivot].freq == data[c-1].freq && data[pivot].literal < data[c-1].literal || data[pivot].freq < data[c-1].freq); c-- { // data[c-1] > pivot
}
if b >= c {
break
}
// data[b] > pivot; data[c-1] <= pivot
data[b], data[c-1] = data[c-1], data[b]
b++
c--
}
// If hi-c<3 then there are duplicates (by property of median of nine).
// Let's be a bit more conservative, and set border to 5.
protect := hi-c < 5
if !protect && hi-c < (hi-lo)/4 {
// Lets test some points for equality to pivot
dups := 0
if data[pivot].freq == data[hi-1].freq && data[pivot].literal > data[hi-1].literal || data[pivot].freq > data[hi-1].freq { // data[hi-1] = pivot
data[c], data[hi-1] = data[hi-1], data[c]
c++
dups++
}
if data[b-1].freq == data[pivot].freq && data[b-1].literal > data[pivot].literal || data[b-1].freq > data[pivot].freq { // data[b-1] = pivot
b--
dups++
}
// m-lo = (hi-lo)/2 > 6
// b-lo > (hi-lo)*3/4-1 > 8
// ==> m < b ==> data[m] <= pivot
if data[m].freq == data[pivot].freq && data[m].literal > data[pivot].literal || data[m].freq > data[pivot].freq { // data[m] = pivot
data[m], data[b-1] = data[b-1], data[m]
b--
dups++
}
// if at least 2 points are equal to pivot, assume skewed distribution
protect = dups > 1
}
if protect {
// Protect against a lot of duplicates
// Add invariant:
// data[a <= i < b] unexamined
// data[b <= i < c] = pivot
for {
for ; a < b && (data[b-1].freq == data[pivot].freq && data[b-1].literal > data[pivot].literal || data[b-1].freq > data[pivot].freq); b-- { // data[b] == pivot
}
for ; a < b && (data[a].freq == data[pivot].freq && data[a].literal < data[pivot].literal || data[a].freq < data[pivot].freq); a++ { // data[a] < pivot
}
if a >= b {
break
}
// data[a] == pivot; data[b-1] < pivot
data[a], data[b-1] = data[b-1], data[a]
a++
b--
}
}
// Swap pivot into middle
data[pivot], data[b-1] = data[b-1], data[pivot]
return b - 1, c
}
// Insertion sort
func insertionSortByFreq(data []literalNode, a, b int) {
for i := a + 1; i < b; i++ {
for j := i; j > a && (data[j].freq == data[j-1].freq && data[j].literal < data[j-1].literal || data[j].freq < data[j-1].freq); j-- {
data[j], data[j-1] = data[j-1], data[j]
}
}
}
// quickSortByFreq, loosely following Bentley and McIlroy,
// ``Engineering a Sort Function,'' SP&E November 1993.
// medianOfThreeSortByFreq moves the median of the three values data[m0], data[m1], data[m2] into data[m1].
func medianOfThreeSortByFreq(data []literalNode, m1, m0, m2 int) {
// sort 3 elements
if data[m1].freq == data[m0].freq && data[m1].literal < data[m0].literal || data[m1].freq < data[m0].freq {
data[m1], data[m0] = data[m0], data[m1]
}
// data[m0] <= data[m1]
if data[m2].freq == data[m1].freq && data[m2].literal < data[m1].literal || data[m2].freq < data[m1].freq {
data[m2], data[m1] = data[m1], data[m2]
// data[m0] <= data[m2] && data[m1] < data[m2]
if data[m1].freq == data[m0].freq && data[m1].literal < data[m0].literal || data[m1].freq < data[m0].freq {
data[m1], data[m0] = data[m0], data[m1]
}
}
// now data[m0] <= data[m1] <= data[m2]
}
Server/vendor/github.com/klauspost/compress/flate/huffman_sortByLiteral.go
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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
// Sort sorts data.
// It makes one call to data.Len to determine n, and O(n*log(n)) calls to
// data.Less and data.Swap. The sort is not guaranteed to be stable.
func sortByLiteral(data []literalNode) {
n := len(data)
quickSort(data, 0, n, maxDepth(n))
}
func quickSort(data []literalNode, a, b, maxDepth int) {
for b-a > 12 { // Use ShellSort for slices <= 12 elements
if maxDepth == 0 {
heapSort(data, a, b)
return
}
maxDepth--
mlo, mhi := doPivot(data, a, b)
// Avoiding recursion on the larger subproblem guarantees
// a stack depth of at most lg(b-a).
if mlo-a < b-mhi {
quickSort(data, a, mlo, maxDepth)
a = mhi // i.e., quickSort(data, mhi, b)
} else {
quickSort(data, mhi, b, maxDepth)
b = mlo // i.e., quickSort(data, a, mlo)
}
}
if b-a > 1 {
// Do ShellSort pass with gap 6
// It could be written in this simplified form cause b-a <= 12
for i := a + 6; i < b; i++ {
if data[i].literal < data[i-6].literal {
data[i], data[i-6] = data[i-6], data[i]
}
}
insertionSort(data, a, b)
}
}
func heapSort(data []literalNode, a, b int) {
first := a
lo := 0
hi := b - a
// Build heap with greatest element at top.
for i := (hi - 1) / 2; i >= 0; i-- {
siftDown(data, i, hi, first)
}
// Pop elements, largest first, into end of data.
for i := hi - 1; i >= 0; i-- {
data[first], data[first+i] = data[first+i], data[first]
siftDown(data, lo, i, first)
}
}
// siftDown implements the heap property on data[lo, hi).
// first is an offset into the array where the root of the heap lies.
func siftDown(data []literalNode, lo, hi, first int) {
root := lo
for {
child := 2*root + 1
if child >= hi {
break
}
if child+1 < hi && data[first+child].literal < data[first+child+1].literal {
child++
}
if data[first+root].literal > data[first+child].literal {
return
}
data[first+root], data[first+child] = data[first+child], data[first+root]
root = child
}
}
func doPivot(data []literalNode, lo, hi int) (midlo, midhi int) {
m := int(uint(lo+hi) >> 1) // Written like this to avoid integer overflow.
if hi-lo > 40 {
// Tukey's ``Ninther,'' median of three medians of three.
s := (hi - lo) / 8
medianOfThree(data, lo, lo+s, lo+2*s)
medianOfThree(data, m, m-s, m+s)
medianOfThree(data, hi-1, hi-1-s, hi-1-2*s)
}
medianOfThree(data, lo, m, hi-1)
// Invariants are:
// data[lo] = pivot (set up by ChoosePivot)
// data[lo < i < a] < pivot
// data[a <= i < b] <= pivot
// data[b <= i < c] unexamined
// data[c <= i < hi-1] > pivot
// data[hi-1] >= pivot
pivot := lo
a, c := lo+1, hi-1
for ; a < c && data[a].literal < data[pivot].literal; a++ {
}
b := a
for {
for ; b < c && data[pivot].literal > data[b].literal; b++ { // data[b] <= pivot
}
for ; b < c && data[pivot].literal < data[c-1].literal; c-- { // data[c-1] > pivot
}
if b >= c {
break
}
// data[b] > pivot; data[c-1] <= pivot
data[b], data[c-1] = data[c-1], data[b]
b++
c--
}
// If hi-c<3 then there are duplicates (by property of median of nine).
// Let's be a bit more conservative, and set border to 5.
protect := hi-c < 5
if !protect && hi-c < (hi-lo)/4 {
// Lets test some points for equality to pivot
dups := 0
if data[pivot].literal > data[hi-1].literal { // data[hi-1] = pivot
data[c], data[hi-1] = data[hi-1], data[c]
c++
dups++
}
if data[b-1].literal > data[pivot].literal { // data[b-1] = pivot
b--
dups++
}
// m-lo = (hi-lo)/2 > 6
// b-lo > (hi-lo)*3/4-1 > 8
// ==> m < b ==> data[m] <= pivot
if data[m].literal > data[pivot].literal { // data[m] = pivot
data[m], data[b-1] = data[b-1], data[m]
b--
dups++
}
// if at least 2 points are equal to pivot, assume skewed distribution
protect = dups > 1
}
if protect {
// Protect against a lot of duplicates
// Add invariant:
// data[a <= i < b] unexamined
// data[b <= i < c] = pivot
for {
for ; a < b && data[b-1].literal > data[pivot].literal; b-- { // data[b] == pivot
}
for ; a < b && data[a].literal < data[pivot].literal; a++ { // data[a] < pivot
}
if a >= b {
break
}
// data[a] == pivot; data[b-1] < pivot
data[a], data[b-1] = data[b-1], data[a]
a++
b--
}
}
// Swap pivot into middle
data[pivot], data[b-1] = data[b-1], data[pivot]
return b - 1, c
}
// Insertion sort
func insertionSort(data []literalNode, a, b int) {
for i := a + 1; i < b; i++ {
for j := i; j > a && data[j].literal < data[j-1].literal; j-- {
data[j], data[j-1] = data[j-1], data[j]
}
}
}
// maxDepth returns a threshold at which quicksort should switch
// to heapsort. It returns 2*ceil(lg(n+1)).
func maxDepth(n int) int {
var depth int
for i := n; i > 0; i >>= 1 {
depth++
}
return depth * 2
}
// medianOfThree moves the median of the three values data[m0], data[m1], data[m2] into data[m1].
func medianOfThree(data []literalNode, m1, m0, m2 int) {
// sort 3 elements
if data[m1].literal < data[m0].literal {
data[m1], data[m0] = data[m0], data[m1]
}
// data[m0] <= data[m1]
if data[m2].literal < data[m1].literal {
data[m2], data[m1] = data[m1], data[m2]
// data[m0] <= data[m2] && data[m1] < data[m2]
if data[m1].literal < data[m0].literal {
data[m1], data[m0] = data[m0], data[m1]
}
}
// now data[m0] <= data[m1] <= data[m2]
}
Server/vendor/github.com/klauspost/compress/flate/inflate.go
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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package flate implements the DEFLATE compressed data format, described in
// RFC 1951. The gzip and zlib packages implement access to DEFLATE-based file
// formats.
package flate
import (
"bufio"
"compress/flate"
"fmt"
"io"
"math/bits"
"sync"
)
const (
maxCodeLen = 16 // max length of Huffman code
maxCodeLenMask = 15 // mask for max length of Huffman code
// The next three numbers come from the RFC section 3.2.7, with the
// additional proviso in section 3.2.5 which implies that distance codes
// 30 and 31 should never occur in compressed data.
maxNumLit = 286
maxNumDist = 30
numCodes = 19 // number of codes in Huffman meta-code
debugDecode = false
)
// Value of length - 3 and extra bits.
type lengthExtra struct {
length, extra uint8
}
var decCodeToLen = [32]lengthExtra{{length: 0x0, extra: 0x0}, {length: 0x1, extra: 0x0}, {length: 0x2, extra: 0x0}, {length: 0x3, extra: 0x0}, {length: 0x4, extra: 0x0}, {length: 0x5, extra: 0x0}, {length: 0x6, extra: 0x0}, {length: 0x7, extra: 0x0}, {length: 0x8, extra: 0x1}, {length: 0xa, extra: 0x1}, {length: 0xc, extra: 0x1}, {length: 0xe, extra: 0x1}, {length: 0x10, extra: 0x2}, {length: 0x14, extra: 0x2}, {length: 0x18, extra: 0x2}, {length: 0x1c, extra: 0x2}, {length: 0x20, extra: 0x3}, {length: 0x28, extra: 0x3}, {length: 0x30, extra: 0x3}, {length: 0x38, extra: 0x3}, {length: 0x40, extra: 0x4}, {length: 0x50, extra: 0x4}, {length: 0x60, extra: 0x4}, {length: 0x70, extra: 0x4}, {length: 0x80, extra: 0x5}, {length: 0xa0, extra: 0x5}, {length: 0xc0, extra: 0x5}, {length: 0xe0, extra: 0x5}, {length: 0xff, extra: 0x0}, {length: 0x0, extra: 0x0}, {length: 0x0, extra: 0x0}, {length: 0x0, extra: 0x0}}
var bitMask32 = [32]uint32{
0, 1, 3, 7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF,
0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF,
0x1ffff, 0x3ffff, 0x7FFFF, 0xfFFFF, 0x1fFFFF, 0x3fFFFF, 0x7fFFFF, 0xffFFFF,
0x1ffFFFF, 0x3ffFFFF, 0x7ffFFFF, 0xfffFFFF, 0x1fffFFFF, 0x3fffFFFF, 0x7fffFFFF,
} // up to 32 bits
// Initialize the fixedHuffmanDecoder only once upon first use.
var fixedOnce sync.Once
var fixedHuffmanDecoder huffmanDecoder
// A CorruptInputError reports the presence of corrupt input at a given offset.
type CorruptInputError = flate.CorruptInputError
// An InternalError reports an error in the flate code itself.
type InternalError string
func (e InternalError) Error() string { return "flate: internal error: " + string(e) }
// A ReadError reports an error encountered while reading input.
//
// Deprecated: No longer returned.
type ReadError = flate.ReadError
// A WriteError reports an error encountered while writing output.
//
// Deprecated: No longer returned.
type WriteError = flate.WriteError
// Resetter resets a ReadCloser returned by NewReader or NewReaderDict to
// to switch to a new underlying Reader. This permits reusing a ReadCloser
// instead of allocating a new one.
type Resetter interface {
// Reset discards any buffered data and resets the Resetter as if it was
// newly initialized with the given reader.
Reset(r io.Reader, dict []byte) error
}
// The data structure for decoding Huffman tables is based on that of
// zlib. There is a lookup table of a fixed bit width (huffmanChunkBits),
// For codes smaller than the table width, there are multiple entries
// (each combination of trailing bits has the same value). For codes
// larger than the table width, the table contains a link to an overflow
// table. The width of each entry in the link table is the maximum code
// size minus the chunk width.
//
// Note that you can do a lookup in the table even without all bits
// filled. Since the extra bits are zero, and the DEFLATE Huffman codes
// have the property that shorter codes come before longer ones, the
// bit length estimate in the result is a lower bound on the actual
// number of bits.
//
// See the following:
// http://www.gzip.org/algorithm.txt
// chunk & 15 is number of bits
// chunk >> 4 is value, including table link
const (
huffmanChunkBits = 9
huffmanNumChunks = 1 << huffmanChunkBits
huffmanCountMask = 15
huffmanValueShift = 4
)
type huffmanDecoder struct {
maxRead int // the maximum number of bits we can read and not overread
chunks *[huffmanNumChunks]uint16 // chunks as described above
links [][]uint16 // overflow links
linkMask uint32 // mask the width of the link table
}
// Initialize Huffman decoding tables from array of code lengths.
// Following this function, h is guaranteed to be initialized into a complete
// tree (i.e., neither over-subscribed nor under-subscribed). The exception is a
// degenerate case where the tree has only a single symbol with length 1. Empty
// trees are permitted.
func (h *huffmanDecoder) init(lengths []int) bool {
// Sanity enables additional runtime tests during Huffman
// table construction. It's intended to be used during
// development to supplement the currently ad-hoc unit tests.
const sanity = false
if h.chunks == nil {
h.chunks = new([huffmanNumChunks]uint16)
}
if h.maxRead != 0 {
*h = huffmanDecoder{chunks: h.chunks, links: h.links}
}
// Count number of codes of each length,
// compute maxRead and max length.
var count [maxCodeLen]int
var min, max int
for _, n := range lengths {
if n == 0 {
continue
}
if min == 0 || n < min {
min = n
}
if n > max {
max = n
}
count[n&maxCodeLenMask]++
}
// Empty tree. The decompressor.huffSym function will fail later if the tree
// is used. Technically, an empty tree is only valid for the HDIST tree and
// not the HCLEN and HLIT tree. However, a stream with an empty HCLEN tree
// is guaranteed to fail since it will attempt to use the tree to decode the
// codes for the HLIT and HDIST trees. Similarly, an empty HLIT tree is
// guaranteed to fail later since the compressed data section must be
// composed of at least one symbol (the end-of-block marker).
if max == 0 {
return true
}
code := 0
var nextcode [maxCodeLen]int
for i := min; i <= max; i++ {
code <<= 1
nextcode[i&maxCodeLenMask] = code
code += count[i&maxCodeLenMask]
}
// Check that the coding is complete (i.e., that we've
// assigned all 2-to-the-max possible bit sequences).
// Exception: To be compatible with zlib, we also need to
// accept degenerate single-code codings. See also
// TestDegenerateHuffmanCoding.
if code != 1<<uint(max) && !(code == 1 && max == 1) {
if debugDecode {
fmt.Println("coding failed, code, max:", code, max, code == 1<<uint(max), code == 1 && max == 1, "(one should be true)")
}
return false
}
h.maxRead = min
chunks := h.chunks[:]
for i := range chunks {
chunks[i] = 0
}
if max > huffmanChunkBits {
numLinks := 1 << (uint(max) - huffmanChunkBits)
h.linkMask = uint32(numLinks - 1)
// create link tables
link := nextcode[huffmanChunkBits+1] >> 1
if cap(h.links) < huffmanNumChunks-link {
h.links = make([][]uint16, huffmanNumChunks-link)
} else {
h.links = h.links[:huffmanNumChunks-link]
}
for j := uint(link); j < huffmanNumChunks; j++ {
reverse := int(bits.Reverse16(uint16(j)))
reverse >>= uint(16 - huffmanChunkBits)
off := j - uint(link)
if sanity && h.chunks[reverse] != 0 {
panic("impossible: overwriting existing chunk")
}
h.chunks[reverse] = uint16(off<<huffmanValueShift | (huffmanChunkBits + 1))
if cap(h.links[off]) < numLinks {
h.links[off] = make([]uint16, numLinks)
} else {
h.links[off] = h.links[off][:numLinks]
}
}
} else {
h.links = h.links[:0]
}
for i, n := range lengths {
if n == 0 {
continue
}
code := nextcode[n]
nextcode[n]++
chunk := uint16(i<<huffmanValueShift | n)
reverse := int(bits.Reverse16(uint16(code)))
reverse >>= uint(16 - n)
if n <= huffmanChunkBits {
for off := reverse; off < len(h.chunks); off += 1 << uint(n) {
// We should never need to overwrite
// an existing chunk. Also, 0 is
// never a valid chunk, because the
// lower 4 "count" bits should be
// between 1 and 15.
if sanity && h.chunks[off] != 0 {
panic("impossible: overwriting existing chunk")
}
h.chunks[off] = chunk
}
} else {
j := reverse & (huffmanNumChunks - 1)
if sanity && h.chunks[j]&huffmanCountMask != huffmanChunkBits+1 {
// Longer codes should have been
// associated with a link table above.
panic("impossible: not an indirect chunk")
}
value := h.chunks[j] >> huffmanValueShift
linktab := h.links[value]
reverse >>= huffmanChunkBits
for off := reverse; off < len(linktab); off += 1 << uint(n-huffmanChunkBits) {
if sanity && linktab[off] != 0 {
panic("impossible: overwriting existing chunk")
}
linktab[off] = chunk
}
}
}
if sanity {
// Above we've sanity checked that we never overwrote
// an existing entry. Here we additionally check that
// we filled the tables completely.
for i, chunk := range h.chunks {
if chunk == 0 {
// As an exception, in the degenerate
// single-code case, we allow odd
// chunks to be missing.
if code == 1 && i%2 == 1 {
continue
}
panic("impossible: missing chunk")
}
}
for _, linktab := range h.links {
for _, chunk := range linktab {
if chunk == 0 {
panic("impossible: missing chunk")
}
}
}
}
return true
}
// Reader is the actual read interface needed by NewReader.
// If the passed in io.Reader does not also have ReadByte,
// the NewReader will introduce its own buffering.
type Reader interface {
io.Reader
io.ByteReader
}
type step uint8
const (
copyData step = iota + 1
nextBlock
huffmanBytesBuffer
huffmanBytesReader
huffmanBufioReader
huffmanStringsReader
huffmanGenericReader
)
// flushMode tells decompressor when to return data
type flushMode uint8
const (
syncFlush flushMode = iota // return data after sync flush block
partialFlush // return data after each block
)
// Decompress state.
type decompressor struct {
// Input source.
r Reader
roffset int64
// Huffman decoders for literal/length, distance.
h1, h2 huffmanDecoder
// Length arrays used to define Huffman codes.
bits *[maxNumLit + maxNumDist]int
codebits *[numCodes]int
// Output history, buffer.
dict dictDecoder
// Next step in the decompression,
// and decompression state.
step step
stepState int
err error
toRead []byte
hl, hd *huffmanDecoder
copyLen int
copyDist int
// Temporary buffer (avoids repeated allocation).
buf [4]byte
// Input bits, in top of b.
b uint32
nb uint
final bool
flushMode flushMode
}
func (f *decompressor) nextBlock() {
for f.nb < 1+2 {
if f.err = f.moreBits(); f.err != nil {
return
}
}
f.final = f.b&1 == 1
f.b >>= 1
typ := f.b & 3
f.b >>= 2
f.nb -= 1 + 2
switch typ {
case 0:
f.dataBlock()
if debugDecode {
fmt.Println("stored block")
}
case 1:
// compressed, fixed Huffman tables
f.hl = &fixedHuffmanDecoder
f.hd = nil
f.huffmanBlockDecoder()
if debugDecode {
fmt.Println("predefinied huffman block")
}
case 2:
// compressed, dynamic Huffman tables
if f.err = f.readHuffman(); f.err != nil {
break
}
f.hl = &f.h1
f.hd = &f.h2
f.huffmanBlockDecoder()
if debugDecode {
fmt.Println("dynamic huffman block")
}
default:
// 3 is reserved.
if debugDecode {
fmt.Println("reserved data block encountered")
}
f.err = CorruptInputError(f.roffset)
}
}
func (f *decompressor) Read(b []byte) (int, error) {
for {
if len(f.toRead) > 0 {
n := copy(b, f.toRead)
f.toRead = f.toRead[n:]
if len(f.toRead) == 0 {
return n, f.err
}
return n, nil
}
if f.err != nil {
return 0, f.err
}
f.doStep()
if f.err != nil && len(f.toRead) == 0 {
f.toRead = f.dict.readFlush() // Flush what's left in case of error
}
}
}
// WriteTo implements the io.WriteTo interface for io.Copy and friends.
func (f *decompressor) WriteTo(w io.Writer) (int64, error) {
total := int64(0)
flushed := false
for {
if len(f.toRead) > 0 {
n, err := w.Write(f.toRead)
total += int64(n)
if err != nil {
f.err = err
return total, err
}
if n != len(f.toRead) {
return total, io.ErrShortWrite
}
f.toRead = f.toRead[:0]
}
if f.err != nil && flushed {
if f.err == io.EOF {
return total, nil
}
return total, f.err
}
if f.err == nil {
f.doStep()
}
if len(f.toRead) == 0 && f.err != nil && !flushed {
f.toRead = f.dict.readFlush() // Flush what's left in case of error
flushed = true
}
}
}
func (f *decompressor) Close() error {
if f.err == io.EOF {
return nil
}
return f.err
}
// RFC 1951 section 3.2.7.
// Compression with dynamic Huffman codes
var codeOrder = [...]int{16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}
func (f *decompressor) readHuffman() error {
// HLIT[5], HDIST[5], HCLEN[4].
for f.nb < 5+5+4 {
if err := f.moreBits(); err != nil {
return err
}
}
nlit := int(f.b&0x1F) + 257
if nlit > maxNumLit {
if debugDecode {
fmt.Println("nlit > maxNumLit", nlit)
}
return CorruptInputError(f.roffset)
}
f.b >>= 5
ndist := int(f.b&0x1F) + 1
if ndist > maxNumDist {
if debugDecode {
fmt.Println("ndist > maxNumDist", ndist)
}
return CorruptInputError(f.roffset)
}
f.b >>= 5
nclen := int(f.b&0xF) + 4
// numCodes is 19, so nclen is always valid.
f.b >>= 4
f.nb -= 5 + 5 + 4
// (HCLEN+4)*3 bits: code lengths in the magic codeOrder order.
for i := range nclen {
for f.nb < 3 {
if err := f.moreBits(); err != nil {
return err
}
}
f.codebits[codeOrder[i]] = int(f.b & 0x7)
f.b >>= 3
f.nb -= 3
}
for i := nclen; i < len(codeOrder); i++ {
f.codebits[codeOrder[i]] = 0
}
if !f.h1.init(f.codebits[0:]) {
if debugDecode {
fmt.Println("init codebits failed")
}
return CorruptInputError(f.roffset)
}
// HLIT + 257 code lengths, HDIST + 1 code lengths,
// using the code length Huffman code.
for i, n := 0, nlit+ndist; i < n; {
x, err := f.huffSym(&f.h1)
if err != nil {
return err
}
if x < 16 {
// Actual length.
f.bits[i] = x
i++
continue
}
// Repeat previous length or zero.
var rep int
var nb uint
var b int
switch x {
default:
return InternalError("unexpected length code")
case 16:
rep = 3
nb = 2
if i == 0 {
if debugDecode {
fmt.Println("i==0")
}
return CorruptInputError(f.roffset)
}
b = f.bits[i-1]
case 17:
rep = 3
nb = 3
b = 0
case 18:
rep = 11
nb = 7
b = 0
}
for f.nb < nb {
if err := f.moreBits(); err != nil {
if debugDecode {
fmt.Println("morebits:", err)
}
return err
}
}
rep += int(f.b & uint32(1<<(nb&regSizeMaskUint32)-1))
f.b >>= nb & regSizeMaskUint32
f.nb -= nb
if i+rep > n {
if debugDecode {
fmt.Println("i+rep > n", i, rep, n)
}
return CorruptInputError(f.roffset)
}
for j := 0; j < rep; j++ {
f.bits[i] = b
i++
}
}
if !f.h1.init(f.bits[0:nlit]) || !f.h2.init(f.bits[nlit:nlit+ndist]) {
if debugDecode {
fmt.Println("init2 failed")
}
return CorruptInputError(f.roffset)
}
// As an optimization, we can initialize the maxRead bits to read at a time
// for the HLIT tree to the length of the EOB marker since we know that
// every block must terminate with one. This preserves the property that
// we never read any extra bytes after the end of the DEFLATE stream.
if f.h1.maxRead < f.bits[endBlockMarker] {
f.h1.maxRead = f.bits[endBlockMarker]
}
if !f.final {
// If not the final block, the smallest block possible is
// a predefined table, BTYPE=01, with a single EOB marker.
// This will take up 3 + 7 bits.
f.h1.maxRead += 10
}
return nil
}
// Copy a single uncompressed data block from input to output.
func (f *decompressor) dataBlock() {
// Uncompressed.
// Discard current half-byte.
left := (f.nb) & 7
f.nb -= left
f.b >>= left
offBytes := f.nb >> 3
// Unfilled values will be overwritten.
f.buf[0] = uint8(f.b)
f.buf[1] = uint8(f.b >> 8)
f.buf[2] = uint8(f.b >> 16)
f.buf[3] = uint8(f.b >> 24)
f.roffset += int64(offBytes)
f.nb, f.b = 0, 0
// Length then ones-complement of length.
nr, err := io.ReadFull(f.r, f.buf[offBytes:4])
f.roffset += int64(nr)
if err != nil {
f.err = noEOF(err)
return
}
n := uint16(f.buf[0]) | uint16(f.buf[1])<<8
nn := uint16(f.buf[2]) | uint16(f.buf[3])<<8
if nn != ^n {
if debugDecode {
ncomp := ^n
fmt.Println("uint16(nn) != uint16(^n)", nn, ncomp)
}
f.err = CorruptInputError(f.roffset)
return
}
if n == 0 {
if f.flushMode == syncFlush {
f.toRead = f.dict.readFlush()
}
f.finishBlock()
return
}
f.copyLen = int(n)
f.copyData()
}
// copyData copies f.copyLen bytes from the underlying reader into f.hist.
// It pauses for reads when f.hist is full.
func (f *decompressor) copyData() {
buf := f.dict.writeSlice()
if len(buf) > f.copyLen {
buf = buf[:f.copyLen]
}
cnt, err := io.ReadFull(f.r, buf)
f.roffset += int64(cnt)
f.copyLen -= cnt
f.dict.writeMark(cnt)
if err != nil {
f.err = noEOF(err)
return
}
if f.dict.availWrite() == 0 || f.copyLen > 0 {
f.toRead = f.dict.readFlush()
f.step = copyData
return
}
f.finishBlock()
}
func (f *decompressor) finishBlock() {
if f.final {
if f.dict.availRead() > 0 {
f.toRead = f.dict.readFlush()
}
f.err = io.EOF
} else if f.flushMode == partialFlush && f.dict.availRead() > 0 {
f.toRead = f.dict.readFlush()
}
f.step = nextBlock
}
func (f *decompressor) doStep() {
switch f.step {
case copyData:
f.copyData()
case nextBlock:
f.nextBlock()
case huffmanBytesBuffer:
f.huffmanBytesBuffer()
case huffmanBytesReader:
f.huffmanBytesReader()
case huffmanBufioReader:
f.huffmanBufioReader()
case huffmanStringsReader:
f.huffmanStringsReader()
case huffmanGenericReader:
f.huffmanGenericReader()
default:
panic("BUG: unexpected step state")
}
}
// noEOF returns err, unless err == io.EOF, in which case it returns io.ErrUnexpectedEOF.
func noEOF(e error) error {
if e == io.EOF {
return io.ErrUnexpectedEOF
}
return e
}
func (f *decompressor) moreBits() error {
c, err := f.r.ReadByte()
if err != nil {
return noEOF(err)
}
f.roffset++
f.b |= uint32(c) << (f.nb & regSizeMaskUint32)
f.nb += 8
return nil
}
// Read the next Huffman-encoded symbol from f according to h.
func (f *decompressor) huffSym(h *huffmanDecoder) (int, error) {
// Since a huffmanDecoder can be empty or be composed of a degenerate tree
// with single element, huffSym must error on these two edge cases. In both
// cases, the chunks slice will be 0 for the invalid sequence, leading it
// satisfy the n == 0 check below.
n := uint(h.maxRead)
// Optimization. Compiler isn't smart enough to keep f.b,f.nb in registers,
// but is smart enough to keep local variables in registers, so use nb and b,
// inline call to moreBits and reassign b,nb back to f on return.
nb, b := f.nb, f.b
for {
for nb < n {
c, err := f.r.ReadByte()
if err != nil {
f.b = b
f.nb = nb
return 0, noEOF(err)
}
f.roffset++
b |= uint32(c) << (nb & regSizeMaskUint32)
nb += 8
}
chunk := h.chunks[b&(huffmanNumChunks-1)]
n = uint(chunk & huffmanCountMask)
if n > huffmanChunkBits {
chunk = h.links[chunk>>huffmanValueShift][(b>>huffmanChunkBits)&h.linkMask]
n = uint(chunk & huffmanCountMask)
}
if n <= nb {
if n == 0 {
f.b = b
f.nb = nb
if debugDecode {
fmt.Println("huffsym: n==0")
}
f.err = CorruptInputError(f.roffset)
return 0, f.err
}
f.b = b >> (n & regSizeMaskUint32)
f.nb = nb - n
return int(chunk >> huffmanValueShift), nil
}
}
}
func makeReader(r io.Reader) Reader {
if rr, ok := r.(Reader); ok {
return rr
}
return bufio.NewReader(r)
}
func fixedHuffmanDecoderInit() {
fixedOnce.Do(func() {
// These come from the RFC section 3.2.6.
var bits [288]int
for i := range 144 {
bits[i] = 8
}
for i := 144; i < 256; i++ {
bits[i] = 9
}
for i := 256; i < 280; i++ {
bits[i] = 7
}
for i := 280; i < 288; i++ {
bits[i] = 8
}
fixedHuffmanDecoder.init(bits[:])
})
}
func (f *decompressor) Reset(r io.Reader, dict []byte) error {
*f = decompressor{
r: makeReader(r),
bits: f.bits,
codebits: f.codebits,
h1: f.h1,
h2: f.h2,
dict: f.dict,
step: nextBlock,
}
f.dict.init(maxMatchOffset, dict)
return nil
}
type ReaderOpt func(*decompressor)
// WithPartialBlock tells decompressor to return after each block,
// so it can read data written with partial flush
func WithPartialBlock() ReaderOpt {
return func(f *decompressor) {
f.flushMode = partialFlush
}
}
// WithDict initializes the reader with a preset dictionary
func WithDict(dict []byte) ReaderOpt {
return func(f *decompressor) {
f.dict.init(maxMatchOffset, dict)
}
}
// NewReaderOpts returns new reader with provided options
func NewReaderOpts(r io.Reader, opts ...ReaderOpt) io.ReadCloser {
fixedHuffmanDecoderInit()
var f decompressor
f.r = makeReader(r)
f.bits = new([maxNumLit + maxNumDist]int)
f.codebits = new([numCodes]int)
f.step = nextBlock
f.dict.init(maxMatchOffset, nil)
for _, opt := range opts {
opt(&f)
}
return &f
}
// NewReader returns a new ReadCloser that can be used
// to read the uncompressed version of r.
// If r does not also implement io.ByteReader,
// the decompressor may read more data than necessary from r.
// It is the caller's responsibility to call Close on the ReadCloser
// when finished reading.
//
// The ReadCloser returned by NewReader also implements Resetter.
func NewReader(r io.Reader) io.ReadCloser {
return NewReaderOpts(r)
}
// NewReaderDict is like NewReader but initializes the reader
// with a preset dictionary. The returned Reader behaves as if
// the uncompressed data stream started with the given dictionary,
// which has already been read. NewReaderDict is typically used
// to read data compressed by NewWriterDict.
//
// The ReadCloser returned by NewReader also implements Resetter.
func NewReaderDict(r io.Reader, dict []byte) io.ReadCloser {
return NewReaderOpts(r, WithDict(dict))
}
Server/vendor/github.com/klauspost/compress/flate/inflate_gen.go
Generated Vendored
+1283
View File
File diff suppressed because it is too large Load Diff
Server/vendor/github.com/klauspost/compress/flate/level1.go
Generated Vendored
+215
View File
@@ -0,0 +1,215 @@
package flate
import (
"fmt"
"github.com/klauspost/compress/internal/le"
)
// fastGen maintains the table for matches,
// and the previous byte block for level 2.
// This is the generic implementation.
type fastEncL1 struct {
fastGen
table [tableSize]tableEntry
}
// EncodeL1 uses a similar algorithm to level 1
func (e *fastEncL1) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
hashBytes = 5
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
for {
const skipLog = 5
const doEvery = 2
nextS := s
var candidate tableEntry
var t int32
for {
nextHash := hashLen(cv, tableBits, hashBytes)
candidate = e.table[nextHash]
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
now := load6432(src, nextS)
e.table[nextHash] = tableEntry{offset: s + e.cur}
nextHash = hashLen(now, tableBits, hashBytes)
t = candidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
e.table[nextHash] = tableEntry{offset: nextS + e.cur}
break
}
// Do one right away...
cv = now
s = nextS
nextS++
candidate = e.table[nextHash]
now >>= 8
e.table[nextHash] = tableEntry{offset: s + e.cur}
t = candidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
e.table[nextHash] = tableEntry{offset: nextS + e.cur}
break
}
cv = now
s = nextS
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
for {
// Invariant: we have a 4-byte match at s, and no need to emit any
// literal bytes prior to s.
// Extend the 4-byte match as long as possible.
l := e.matchlenLong(int(s+4), int(t+4), src) + 4
// Extend backwards
for t > 0 && s > nextEmit && le.Load8(src, t-1) == le.Load8(src, s-1) {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
// Save the match found
if false {
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
} else {
// Inlined...
xoffset := uint32(s - t - baseMatchOffset)
xlength := l
oc := offsetCode(xoffset)
xoffset |= oc << 16
for xlength > 0 {
xl := xlength
if xl > 258 {
if xl > 258+baseMatchLength {
xl = 258
} else {
xl = 258 - baseMatchLength
}
}
xlength -= xl
xl -= baseMatchLength
dst.extraHist[lengthCodes1[uint8(xl)]]++
dst.offHist[oc]++
dst.tokens[dst.n] = token(matchType | uint32(xl)<<lengthShift | xoffset)
dst.n++
}
}
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
// Index first pair after match end.
if int(s+l+8) < len(src) {
cv := load6432(src, s)
e.table[hashLen(cv, tableBits, hashBytes)] = tableEntry{offset: s + e.cur}
}
goto emitRemainder
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-2 and at s. If
// another emitCopy is not our next move, also calculate nextHash
// at s+1. At least on GOARCH=amd64, these three hash calculations
// are faster as one load64 call (with some shifts) instead of
// three load32 calls.
x := load6432(src, s-2)
o := e.cur + s - 2
prevHash := hashLen(x, tableBits, hashBytes)
e.table[prevHash] = tableEntry{offset: o}
x >>= 16
currHash := hashLen(x, tableBits, hashBytes)
candidate = e.table[currHash]
e.table[currHash] = tableEntry{offset: o + 2}
t = candidate.offset - e.cur
if s-t > maxMatchOffset || uint32(x) != load3232(src, t) {
cv = x >> 8
s++
break
}
}
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}
Server/vendor/github.com/klauspost/compress/flate/level2.go
Generated Vendored
+214
View File
@@ -0,0 +1,214 @@
package flate
import "fmt"
// fastGen maintains the table for matches,
// and the previous byte block for level 2.
// This is the generic implementation.
type fastEncL2 struct {
fastGen
table [bTableSize]tableEntry
}
// EncodeL2 uses a similar algorithm to level 1, but is capable
// of matching across blocks giving better compression at a small slowdown.
func (e *fastEncL2) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
hashBytes = 5
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
for {
// When should we start skipping if we haven't found matches in a long while.
const skipLog = 5
const doEvery = 2
nextS := s
var candidate tableEntry
for {
nextHash := hashLen(cv, bTableBits, hashBytes)
s = nextS
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
candidate = e.table[nextHash]
now := load6432(src, nextS)
e.table[nextHash] = tableEntry{offset: s + e.cur}
nextHash = hashLen(now, bTableBits, hashBytes)
offset := s - (candidate.offset - e.cur)
if offset < maxMatchOffset && uint32(cv) == load3232(src, candidate.offset-e.cur) {
e.table[nextHash] = tableEntry{offset: nextS + e.cur}
break
}
// Do one right away...
cv = now
s = nextS
nextS++
candidate = e.table[nextHash]
now >>= 8
e.table[nextHash] = tableEntry{offset: s + e.cur}
offset = s - (candidate.offset - e.cur)
if offset < maxMatchOffset && uint32(cv) == load3232(src, candidate.offset-e.cur) {
break
}
cv = now
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
// Call emitCopy, and then see if another emitCopy could be our next
// move. Repeat until we find no match for the input immediately after
// what was consumed by the last emitCopy call.
//
// If we exit this loop normally then we need to call emitLiteral next,
// though we don't yet know how big the literal will be. We handle that
// by proceeding to the next iteration of the main loop. We also can
// exit this loop via goto if we get close to exhausting the input.
for {
// Invariant: we have a 4-byte match at s, and no need to emit any
// literal bytes prior to s.
// Extend the 4-byte match as long as possible.
t := candidate.offset - e.cur
l := e.matchlenLong(int(s+4), int(t+4), src) + 4
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
// Index first pair after match end.
if int(s+l+8) < len(src) {
cv := load6432(src, s)
e.table[hashLen(cv, bTableBits, hashBytes)] = tableEntry{offset: s + e.cur}
}
goto emitRemainder
}
// Store every second hash in-between, but offset by 1.
for i := s - l + 2; i < s-5; i += 7 {
x := load6432(src, i)
nextHash := hashLen(x, bTableBits, hashBytes)
e.table[nextHash] = tableEntry{offset: e.cur + i}
// Skip one
x >>= 16
nextHash = hashLen(x, bTableBits, hashBytes)
e.table[nextHash] = tableEntry{offset: e.cur + i + 2}
// Skip one
x >>= 16
nextHash = hashLen(x, bTableBits, hashBytes)
e.table[nextHash] = tableEntry{offset: e.cur + i + 4}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-2 to s. If
// another emitCopy is not our next move, also calculate nextHash
// at s+1. At least on GOARCH=amd64, these three hash calculations
// are faster as one load64 call (with some shifts) instead of
// three load32 calls.
x := load6432(src, s-2)
o := e.cur + s - 2
prevHash := hashLen(x, bTableBits, hashBytes)
prevHash2 := hashLen(x>>8, bTableBits, hashBytes)
e.table[prevHash] = tableEntry{offset: o}
e.table[prevHash2] = tableEntry{offset: o + 1}
currHash := hashLen(x>>16, bTableBits, hashBytes)
candidate = e.table[currHash]
e.table[currHash] = tableEntry{offset: o + 2}
offset := s - (candidate.offset - e.cur)
if offset > maxMatchOffset || uint32(x>>16) != load3232(src, candidate.offset-e.cur) {
cv = x >> 24
s++
break
}
}
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}
Server/vendor/github.com/klauspost/compress/flate/level3.go
Generated Vendored
+241
View File
@@ -0,0 +1,241 @@
package flate
import "fmt"
// fastEncL3
type fastEncL3 struct {
fastGen
table [1 << 16]tableEntryPrev
}
// Encode uses a similar algorithm to level 2, will check up to two candidates.
func (e *fastEncL3) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
tableBits = 16
tableSize = 1 << tableBits
hashBytes = 5
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntryPrev{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i]
if v.Cur.offset <= minOff {
v.Cur.offset = 0
} else {
v.Cur.offset = v.Cur.offset - e.cur + maxMatchOffset
}
if v.Prev.offset <= minOff {
v.Prev.offset = 0
} else {
v.Prev.offset = v.Prev.offset - e.cur + maxMatchOffset
}
e.table[i] = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// Skip if too small.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
for {
const skipLog = 7
nextS := s
var candidate tableEntry
for {
nextHash := hashLen(cv, tableBits, hashBytes)
s = nextS
nextS = s + 1 + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
candidates := e.table[nextHash]
now := load6432(src, nextS)
// Safe offset distance until s + 4...
minOffset := e.cur + s - (maxMatchOffset - 4)
e.table[nextHash] = tableEntryPrev{Prev: candidates.Cur, Cur: tableEntry{offset: s + e.cur}}
// Check both candidates
candidate = candidates.Cur
if candidate.offset < minOffset {
cv = now
// Previous will also be invalid, we have nothing.
continue
}
if uint32(cv) == load3232(src, candidate.offset-e.cur) {
if candidates.Prev.offset < minOffset || uint32(cv) != load3232(src, candidates.Prev.offset-e.cur) {
break
}
// Both match and are valid, pick longest.
offset := s - (candidate.offset - e.cur)
o2 := s - (candidates.Prev.offset - e.cur)
l1, l2 := matchLen(src[s+4:], src[s-offset+4:]), matchLen(src[s+4:], src[s-o2+4:])
if l2 > l1 {
candidate = candidates.Prev
}
break
} else {
// We only check if value mismatches.
// Offset will always be invalid in other cases.
candidate = candidates.Prev
if candidate.offset > minOffset && uint32(cv) == load3232(src, candidate.offset-e.cur) {
break
}
}
cv = now
}
// Call emitCopy, and then see if another emitCopy could be our next
// move. Repeat until we find no match for the input immediately after
// what was consumed by the last emitCopy call.
//
// If we exit this loop normally then we need to call emitLiteral next,
// though we don't yet know how big the literal will be. We handle that
// by proceeding to the next iteration of the main loop. We also can
// exit this loop via goto if we get close to exhausting the input.
for {
// Invariant: we have a 4-byte match at s, and no need to emit any
// literal bytes prior to s.
// Extend the 4-byte match as long as possible.
//
t := candidate.offset - e.cur
l := e.matchlenLong(int(s+4), int(t+4), src) + 4
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
t += l
// Index first pair after match end.
if int(t+8) < len(src) && t > 0 {
cv = load6432(src, t)
nextHash := hashLen(cv, tableBits, hashBytes)
e.table[nextHash] = tableEntryPrev{
Prev: e.table[nextHash].Cur,
Cur: tableEntry{offset: e.cur + t},
}
}
goto emitRemainder
}
// Store every 5th hash in-between.
for i := s - l + 2; i < s-5; i += 6 {
nextHash := hashLen(load6432(src, i), tableBits, hashBytes)
e.table[nextHash] = tableEntryPrev{
Prev: e.table[nextHash].Cur,
Cur: tableEntry{offset: e.cur + i}}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-2 to s.
x := load6432(src, s-2)
prevHash := hashLen(x, tableBits, hashBytes)
e.table[prevHash] = tableEntryPrev{
Prev: e.table[prevHash].Cur,
Cur: tableEntry{offset: e.cur + s - 2},
}
x >>= 8
prevHash = hashLen(x, tableBits, hashBytes)
e.table[prevHash] = tableEntryPrev{
Prev: e.table[prevHash].Cur,
Cur: tableEntry{offset: e.cur + s - 1},
}
x >>= 8
currHash := hashLen(x, tableBits, hashBytes)
candidates := e.table[currHash]
cv = x
e.table[currHash] = tableEntryPrev{
Prev: candidates.Cur,
Cur: tableEntry{offset: s + e.cur},
}
// Check both candidates
candidate = candidates.Cur
minOffset := e.cur + s - (maxMatchOffset - 4)
if candidate.offset > minOffset {
if uint32(cv) == load3232(src, candidate.offset-e.cur) {
// Found a match...
continue
}
candidate = candidates.Prev
if candidate.offset > minOffset && uint32(cv) == load3232(src, candidate.offset-e.cur) {
// Match at prev...
continue
}
}
cv = x >> 8
s++
break
}
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}
Server/vendor/github.com/klauspost/compress/flate/level4.go
Generated Vendored
+221
View File
@@ -0,0 +1,221 @@
package flate
import "fmt"
type fastEncL4 struct {
fastGen
table [tableSize]tableEntry
bTable [tableSize]tableEntry
}
func (e *fastEncL4) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
hashShortBytes = 4
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
for i := range e.bTable[:] {
e.bTable[i] = tableEntry{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
for i := range e.bTable[:] {
v := e.bTable[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.bTable[i].offset = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
for {
const skipLog = 6
const doEvery = 1
nextS := s
var t int32
for {
nextHashS := hashLen(cv, tableBits, hashShortBytes)
nextHashL := hash7(cv, tableBits)
s = nextS
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
// Fetch a short+long candidate
sCandidate := e.table[nextHashS]
lCandidate := e.bTable[nextHashL]
next := load6432(src, nextS)
entry := tableEntry{offset: s + e.cur}
e.table[nextHashS] = entry
e.bTable[nextHashL] = entry
t = lCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// We got a long match. Use that.
break
}
t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Found a 4 match...
lCandidate = e.bTable[hash7(next, tableBits)]
// If the next long is a candidate, check if we should use that instead...
lOff := lCandidate.offset - e.cur
if nextS-lOff < maxMatchOffset && load3232(src, lOff) == uint32(next) {
l1, l2 := matchLen(src[s+4:], src[t+4:]), matchLen(src[nextS+4:], src[nextS-lOff+4:])
if l2 > l1 {
s = nextS
t = lCandidate.offset - e.cur
}
}
break
}
cv = next
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
// Extend the 4-byte match as long as possible.
l := e.matchlenLong(int(s+4), int(t+4), src) + 4
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
if debugDeflate {
if t >= s {
panic("s-t")
}
if (s - t) > maxMatchOffset {
panic(fmt.Sprintln("mmo", t))
}
if l < baseMatchLength {
panic("bml")
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
// Index first pair after match end.
if int(s+8) < len(src) {
cv := load6432(src, s)
e.table[hashLen(cv, tableBits, hashShortBytes)] = tableEntry{offset: s + e.cur}
e.bTable[hash7(cv, tableBits)] = tableEntry{offset: s + e.cur}
}
goto emitRemainder
}
// Store every 3rd hash in-between
if true {
i := nextS
if i < s-1 {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
t2 := tableEntry{offset: t.offset + 1}
e.bTable[hash7(cv, tableBits)] = t
e.bTable[hash7(cv>>8, tableBits)] = t2
e.table[hashLen(cv>>8, tableBits, hashShortBytes)] = t2
i += 3
for ; i < s-1; i += 3 {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
t2 := tableEntry{offset: t.offset + 1}
e.bTable[hash7(cv, tableBits)] = t
e.bTable[hash7(cv>>8, tableBits)] = t2
e.table[hashLen(cv>>8, tableBits, hashShortBytes)] = t2
}
}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-1 and at s.
x := load6432(src, s-1)
o := e.cur + s - 1
prevHashS := hashLen(x, tableBits, hashShortBytes)
prevHashL := hash7(x, tableBits)
e.table[prevHashS] = tableEntry{offset: o}
e.bTable[prevHashL] = tableEntry{offset: o}
cv = x >> 8
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}
Server/vendor/github.com/klauspost/compress/flate/level5.go
Generated Vendored
+705
View File
@@ -0,0 +1,705 @@
package flate
import "fmt"
type fastEncL5 struct {
fastGen
table [tableSize]tableEntry
bTable [tableSize]tableEntryPrev
}
func (e *fastEncL5) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
hashShortBytes = 4
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
for i := range e.bTable[:] {
e.bTable[i] = tableEntryPrev{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
for i := range e.bTable[:] {
v := e.bTable[i]
if v.Cur.offset <= minOff {
v.Cur.offset = 0
v.Prev.offset = 0
} else {
v.Cur.offset = v.Cur.offset - e.cur + maxMatchOffset
if v.Prev.offset <= minOff {
v.Prev.offset = 0
} else {
v.Prev.offset = v.Prev.offset - e.cur + maxMatchOffset
}
}
e.bTable[i] = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
for {
const skipLog = 6
const doEvery = 1
nextS := s
var l int32
var t int32
for {
nextHashS := hashLen(cv, tableBits, hashShortBytes)
nextHashL := hash7(cv, tableBits)
s = nextS
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
// Fetch a short+long candidate
sCandidate := e.table[nextHashS]
lCandidate := e.bTable[nextHashL]
next := load6432(src, nextS)
entry := tableEntry{offset: s + e.cur}
e.table[nextHashS] = entry
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = entry, eLong.Cur
nextHashS = hashLen(next, tableBits, hashShortBytes)
nextHashL = hash7(next, tableBits)
t = lCandidate.Cur.offset - e.cur
if s-t < maxMatchOffset {
if uint32(cv) == load3232(src, t) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
t2 := lCandidate.Prev.offset - e.cur
if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, t2) {
l = e.matchlen(int(s+4), int(t+4), src) + 4
ml1 := e.matchlen(int(s+4), int(t2+4), src) + 4
if ml1 > l {
t = t2
l = ml1
break
}
}
break
}
t = lCandidate.Prev.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
break
}
}
t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Found a 4 match...
l = e.matchlen(int(s+4), int(t+4), src) + 4
lCandidate = e.bTable[nextHashL]
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
// If the next long is a candidate, use that...
t2 := lCandidate.Cur.offset - e.cur
if nextS-t2 < maxMatchOffset {
if load3232(src, t2) == uint32(next) {
ml := e.matchlen(int(nextS+4), int(t2+4), src) + 4
if ml > l {
t = t2
s = nextS
l = ml
break
}
}
// If the previous long is a candidate, use that...
t2 = lCandidate.Prev.offset - e.cur
if nextS-t2 < maxMatchOffset && load3232(src, t2) == uint32(next) {
ml := e.matchlen(int(nextS+4), int(t2+4), src) + 4
if ml > l {
t = t2
s = nextS
l = ml
break
}
}
}
break
}
cv = next
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
if l == 0 {
// Extend the 4-byte match as long as possible.
l = e.matchlenLong(int(s+4), int(t+4), src) + 4
} else if l == maxMatchLength {
l += e.matchlenLong(int(s+l), int(t+l), src)
}
// Try to locate a better match by checking the end of best match...
if sAt := s + l; l < 30 && sAt < sLimit {
// Allow some bytes at the beginning to mismatch.
// Sweet spot is 2/3 bytes depending on input.
// 3 is only a little better when it is but sometimes a lot worse.
// The skipped bytes are tested in Extend backwards,
// and still picked up as part of the match if they do.
const skipBeginning = 2
eLong := e.bTable[hash7(load6432(src, sAt), tableBits)].Cur.offset
t2 := eLong - e.cur - l + skipBeginning
s2 := s + skipBeginning
off := s2 - t2
if t2 >= 0 && off < maxMatchOffset && off > 0 {
if l2 := e.matchlenLong(int(s2), int(t2), src); l2 > l {
t = t2
l = l2
s = s2
}
}
}
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
if debugDeflate {
if t >= s {
panic(fmt.Sprintln("s-t", s, t))
}
if (s - t) > maxMatchOffset {
panic(fmt.Sprintln("mmo", s-t))
}
if l < baseMatchLength {
panic("bml")
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
goto emitRemainder
}
// Store every 3rd hash in-between.
if true {
const hashEvery = 3
i := s - l + 1
if i < s-1 {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
e.table[hashLen(cv, tableBits, hashShortBytes)] = t
eLong := &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = t, eLong.Cur
// Do an long at i+1
cv >>= 8
t = tableEntry{offset: t.offset + 1}
eLong = &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = t, eLong.Cur
// We only have enough bits for a short entry at i+2
cv >>= 8
t = tableEntry{offset: t.offset + 1}
e.table[hashLen(cv, tableBits, hashShortBytes)] = t
// Skip one - otherwise we risk hitting 's'
i += 4
for ; i < s-1; i += hashEvery {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
t2 := tableEntry{offset: t.offset + 1}
eLong := &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = t, eLong.Cur
e.table[hashLen(cv>>8, tableBits, hashShortBytes)] = t2
}
}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-1 and at s.
x := load6432(src, s-1)
o := e.cur + s - 1
prevHashS := hashLen(x, tableBits, hashShortBytes)
prevHashL := hash7(x, tableBits)
e.table[prevHashS] = tableEntry{offset: o}
eLong := &e.bTable[prevHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: o}, eLong.Cur
cv = x >> 8
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}
// fastEncL5Window is a level 5 encoder,
// but with a custom window size.
type fastEncL5Window struct {
hist []byte
cur int32
maxOffset int32
table [tableSize]tableEntry
bTable [tableSize]tableEntryPrev
}
func (e *fastEncL5Window) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
hashShortBytes = 4
)
maxMatchOffset := e.maxOffset
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
for i := range e.bTable[:] {
e.bTable[i] = tableEntryPrev{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
for i := range e.bTable[:] {
v := e.bTable[i]
if v.Cur.offset <= minOff {
v.Cur.offset = 0
v.Prev.offset = 0
} else {
v.Cur.offset = v.Cur.offset - e.cur + maxMatchOffset
if v.Prev.offset <= minOff {
v.Prev.offset = 0
} else {
v.Prev.offset = v.Prev.offset - e.cur + maxMatchOffset
}
}
e.bTable[i] = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
for {
const skipLog = 6
const doEvery = 1
nextS := s
var l int32
var t int32
for {
nextHashS := hashLen(cv, tableBits, hashShortBytes)
nextHashL := hash7(cv, tableBits)
s = nextS
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
// Fetch a short+long candidate
sCandidate := e.table[nextHashS]
lCandidate := e.bTable[nextHashL]
next := load6432(src, nextS)
entry := tableEntry{offset: s + e.cur}
e.table[nextHashS] = entry
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = entry, eLong.Cur
nextHashS = hashLen(next, tableBits, hashShortBytes)
nextHashL = hash7(next, tableBits)
t = lCandidate.Cur.offset - e.cur
if s-t < maxMatchOffset {
if uint32(cv) == load3232(src, t) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
t2 := lCandidate.Prev.offset - e.cur
if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, t2) {
l = e.matchlen(s+4, t+4, src) + 4
ml1 := e.matchlen(s+4, t2+4, src) + 4
if ml1 > l {
t = t2
l = ml1
break
}
}
break
}
t = lCandidate.Prev.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
break
}
}
t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Found a 4 match...
l = e.matchlen(s+4, t+4, src) + 4
lCandidate = e.bTable[nextHashL]
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
// If the next long is a candidate, use that...
t2 := lCandidate.Cur.offset - e.cur
if nextS-t2 < maxMatchOffset {
if load3232(src, t2) == uint32(next) {
ml := e.matchlen(nextS+4, t2+4, src) + 4
if ml > l {
t = t2
s = nextS
l = ml
break
}
}
// If the previous long is a candidate, use that...
t2 = lCandidate.Prev.offset - e.cur
if nextS-t2 < maxMatchOffset && load3232(src, t2) == uint32(next) {
ml := e.matchlen(nextS+4, t2+4, src) + 4
if ml > l {
t = t2
s = nextS
l = ml
break
}
}
}
break
}
cv = next
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
if l == 0 {
// Extend the 4-byte match as long as possible.
l = e.matchlenLong(s+4, t+4, src) + 4
} else if l == maxMatchLength {
l += e.matchlenLong(s+l, t+l, src)
}
// Try to locate a better match by checking the end of best match...
if sAt := s + l; l < 30 && sAt < sLimit {
// Allow some bytes at the beginning to mismatch.
// Sweet spot is 2/3 bytes depending on input.
// 3 is only a little better when it is but sometimes a lot worse.
// The skipped bytes are tested in Extend backwards,
// and still picked up as part of the match if they do.
const skipBeginning = 2
eLong := e.bTable[hash7(load6432(src, sAt), tableBits)].Cur.offset
t2 := eLong - e.cur - l + skipBeginning
s2 := s + skipBeginning
off := s2 - t2
if t2 >= 0 && off < maxMatchOffset && off > 0 {
if l2 := e.matchlenLong(s2, t2, src); l2 > l {
t = t2
l = l2
s = s2
}
}
}
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
if debugDeflate {
if t >= s {
panic(fmt.Sprintln("s-t", s, t))
}
if (s - t) > maxMatchOffset {
panic(fmt.Sprintln("mmo", s-t))
}
if l < baseMatchLength {
panic("bml")
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
goto emitRemainder
}
// Store every 3rd hash in-between.
if true {
const hashEvery = 3
i := s - l + 1
if i < s-1 {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
e.table[hashLen(cv, tableBits, hashShortBytes)] = t
eLong := &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = t, eLong.Cur
// Do an long at i+1
cv >>= 8
t = tableEntry{offset: t.offset + 1}
eLong = &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = t, eLong.Cur
// We only have enough bits for a short entry at i+2
cv >>= 8
t = tableEntry{offset: t.offset + 1}
e.table[hashLen(cv, tableBits, hashShortBytes)] = t
// Skip one - otherwise we risk hitting 's'
i += 4
for ; i < s-1; i += hashEvery {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
t2 := tableEntry{offset: t.offset + 1}
eLong := &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = t, eLong.Cur
e.table[hashLen(cv>>8, tableBits, hashShortBytes)] = t2
}
}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-1 and at s.
x := load6432(src, s-1)
o := e.cur + s - 1
prevHashS := hashLen(x, tableBits, hashShortBytes)
prevHashL := hash7(x, tableBits)
e.table[prevHashS] = tableEntry{offset: o}
eLong := &e.bTable[prevHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: o}, eLong.Cur
cv = x >> 8
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}
// Reset the encoding table.
func (e *fastEncL5Window) Reset() {
// We keep the same allocs, since we are compressing the same block sizes.
if cap(e.hist) < allocHistory {
e.hist = make([]byte, 0, allocHistory)
}
// We offset current position so everything will be out of reach.
// If we are above the buffer reset it will be cleared anyway since len(hist) == 0.
if e.cur <= int32(bufferReset) {
e.cur += e.maxOffset + int32(len(e.hist))
}
e.hist = e.hist[:0]
}
func (e *fastEncL5Window) addBlock(src []byte) int32 {
// check if we have space already
maxMatchOffset := e.maxOffset
if len(e.hist)+len(src) > cap(e.hist) {
if cap(e.hist) == 0 {
e.hist = make([]byte, 0, allocHistory)
} else {
if cap(e.hist) < int(maxMatchOffset*2) {
panic("unexpected buffer size")
}
// Move down
offset := int32(len(e.hist)) - maxMatchOffset
copy(e.hist[0:maxMatchOffset], e.hist[offset:])
e.cur += offset
e.hist = e.hist[:maxMatchOffset]
}
}
s := int32(len(e.hist))
e.hist = append(e.hist, src...)
return s
}
// matchlen will return the match length between offsets and t in src.
// The maximum length returned is maxMatchLength - 4.
// It is assumed that s > t, that t >=0 and s < len(src).
func (e *fastEncL5Window) matchlen(s, t int32, src []byte) int32 {
if debugDecode {
if t >= s {
panic(fmt.Sprint("t >=s:", t, s))
}
if int(s) >= len(src) {
panic(fmt.Sprint("s >= len(src):", s, len(src)))
}
if t < 0 {
panic(fmt.Sprint("t < 0:", t))
}
if s-t > e.maxOffset {
panic(fmt.Sprint(s, "-", t, "(", s-t, ") > maxMatchLength (", maxMatchOffset, ")"))
}
}
s1 := min(int(s)+maxMatchLength-4, len(src))
// Extend the match to be as long as possible.
return int32(matchLen(src[s:s1], src[t:]))
}
// matchlenLong will return the match length between offsets and t in src.
// It is assumed that s > t, that t >=0 and s < len(src).
func (e *fastEncL5Window) matchlenLong(s, t int32, src []byte) int32 {
if debugDeflate {
if t >= s {
panic(fmt.Sprint("t >=s:", t, s))
}
if int(s) >= len(src) {
panic(fmt.Sprint("s >= len(src):", s, len(src)))
}
if t < 0 {
panic(fmt.Sprint("t < 0:", t))
}
if s-t > e.maxOffset {
panic(fmt.Sprint(s, "-", t, "(", s-t, ") > maxMatchLength (", maxMatchOffset, ")"))
}
}
// Extend the match to be as long as possible.
return int32(matchLen(src[s:], src[t:]))
}
Server/vendor/github.com/klauspost/compress/flate/level6.go
Generated Vendored
+325
View File
@@ -0,0 +1,325 @@
package flate
import "fmt"
type fastEncL6 struct {
fastGen
table [tableSize]tableEntry
bTable [tableSize]tableEntryPrev
}
func (e *fastEncL6) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
hashShortBytes = 4
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
for i := range e.bTable[:] {
e.bTable[i] = tableEntryPrev{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
for i := range e.bTable[:] {
v := e.bTable[i]
if v.Cur.offset <= minOff {
v.Cur.offset = 0
v.Prev.offset = 0
} else {
v.Cur.offset = v.Cur.offset - e.cur + maxMatchOffset
if v.Prev.offset <= minOff {
v.Prev.offset = 0
} else {
v.Prev.offset = v.Prev.offset - e.cur + maxMatchOffset
}
}
e.bTable[i] = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
// Repeat MUST be > 1 and within range
repeat := int32(1)
for {
const skipLog = 7
const doEvery = 1
nextS := s
var l int32
var t int32
for {
nextHashS := hashLen(cv, tableBits, hashShortBytes)
nextHashL := hash7(cv, tableBits)
s = nextS
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
// Fetch a short+long candidate
sCandidate := e.table[nextHashS]
lCandidate := e.bTable[nextHashL]
next := load6432(src, nextS)
entry := tableEntry{offset: s + e.cur}
e.table[nextHashS] = entry
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = entry, eLong.Cur
// Calculate hashes of 'next'
nextHashS = hashLen(next, tableBits, hashShortBytes)
nextHashL = hash7(next, tableBits)
t = lCandidate.Cur.offset - e.cur
if s-t < maxMatchOffset {
if uint32(cv) == load3232(src, t) {
// Long candidate matches at least 4 bytes.
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
// Check the previous long candidate as well.
t2 := lCandidate.Prev.offset - e.cur
if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, t2) {
l = e.matchlen(int(s+4), int(t+4), src) + 4
ml1 := e.matchlen(int(s+4), int(t2+4), src) + 4
if ml1 > l {
t = t2
l = ml1
break
}
}
break
}
// Current value did not match, but check if previous long value does.
t = lCandidate.Prev.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
break
}
}
t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Found a 4 match...
l = e.matchlen(int(s+4), int(t+4), src) + 4
// Look up next long candidate (at nextS)
lCandidate = e.bTable[nextHashL]
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
// Check repeat at s + repOff
const repOff = 1
t2 := s - repeat + repOff
if load3232(src, t2) == uint32(cv>>(8*repOff)) {
ml := e.matchlen(int(s+4+repOff), int(t2+4), src) + 4
if ml > l {
t = t2
l = ml
s += repOff
// Not worth checking more.
break
}
}
// If the next long is a candidate, use that...
t2 = lCandidate.Cur.offset - e.cur
if nextS-t2 < maxMatchOffset {
if load3232(src, t2) == uint32(next) {
ml := e.matchlen(int(nextS+4), int(t2+4), src) + 4
if ml > l {
t = t2
s = nextS
l = ml
// This is ok, but check previous as well.
}
}
// If the previous long is a candidate, use that...
t2 = lCandidate.Prev.offset - e.cur
if nextS-t2 < maxMatchOffset && load3232(src, t2) == uint32(next) {
ml := e.matchlen(int(nextS+4), int(t2+4), src) + 4
if ml > l {
t = t2
s = nextS
l = ml
break
}
}
}
break
}
cv = next
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
// Extend the 4-byte match as long as possible.
if l == 0 {
l = e.matchlenLong(int(s+4), int(t+4), src) + 4
} else if l == maxMatchLength {
l += e.matchlenLong(int(s+l), int(t+l), src)
}
// Try to locate a better match by checking the end-of-match...
if sAt := s + l; sAt < sLimit {
// Allow some bytes at the beginning to mismatch.
// Sweet spot is 2/3 bytes depending on input.
// 3 is only a little better when it is but sometimes a lot worse.
// The skipped bytes are tested in Extend backwards,
// and still picked up as part of the match if they do.
const skipBeginning = 2
eLong := &e.bTable[hash7(load6432(src, sAt), tableBits)]
// Test current
t2 := eLong.Cur.offset - e.cur - l + skipBeginning
s2 := s + skipBeginning
off := s2 - t2
if off < maxMatchOffset {
if off > 0 && t2 >= 0 {
if l2 := e.matchlenLong(int(s2), int(t2), src); l2 > l {
t = t2
l = l2
s = s2
}
}
// Test next:
t2 = eLong.Prev.offset - e.cur - l + skipBeginning
off := s2 - t2
if off > 0 && off < maxMatchOffset && t2 >= 0 {
if l2 := e.matchlenLong(int(s2), int(t2), src); l2 > l {
t = t2
l = l2
s = s2
}
}
}
}
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
if false {
if t >= s {
panic(fmt.Sprintln("s-t", s, t))
}
if (s - t) > maxMatchOffset {
panic(fmt.Sprintln("mmo", s-t))
}
if l < baseMatchLength {
panic("bml")
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
repeat = s - t
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
// Index after match end.
for i := nextS + 1; i < int32(len(src))-8; i += 2 {
cv := load6432(src, i)
e.table[hashLen(cv, tableBits, hashShortBytes)] = tableEntry{offset: i + e.cur}
eLong := &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = tableEntry{offset: i + e.cur}, eLong.Cur
}
goto emitRemainder
}
// Store every long hash in-between and every second short.
if true {
for i := nextS + 1; i < s-1; i += 2 {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
t2 := tableEntry{offset: t.offset + 1}
eLong := &e.bTable[hash7(cv, tableBits)]
eLong2 := &e.bTable[hash7(cv>>8, tableBits)]
e.table[hashLen(cv, tableBits, hashShortBytes)] = t
eLong.Cur, eLong.Prev = t, eLong.Cur
eLong2.Cur, eLong2.Prev = t2, eLong2.Cur
}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-1 and at s.
cv = load6432(src, s)
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}
Server/vendor/github.com/klauspost/compress/flate/matchlen_generic.go
Generated Vendored
+34
View File
@@ -0,0 +1,34 @@
// Copyright 2019+ Klaus Post. All rights reserved.
// License information can be found in the LICENSE file.
package flate
import (
"math/bits"
"github.com/klauspost/compress/internal/le"
)
// matchLen returns the maximum common prefix length of a and b.
// a must be the shortest of the two.
func matchLen(a, b []byte) (n int) {
left := len(a)
for left >= 8 {
diff := le.Load64(a, n) ^ le.Load64(b, n)
if diff != 0 {
return n + bits.TrailingZeros64(diff)>>3
}
n += 8
left -= 8
}
a = a[n:]
b = b[n:]
for i := range a {
if a[i] != b[i] {
break
}
n++
}
return n
}
Server/vendor/github.com/klauspost/compress/flate/regmask_amd64.go
Generated Vendored
+37
View File
@@ -0,0 +1,37 @@
package flate
const (
// Masks for shifts with register sizes of the shift value.
// This can be used to work around the x86 design of shifting by mod register size.
// It can be used when a variable shift is always smaller than the register size.
// reg8SizeMaskX - shift value is 8 bits, shifted is X
reg8SizeMask8 = 7
reg8SizeMask16 = 15
reg8SizeMask32 = 31
reg8SizeMask64 = 63
// reg16SizeMaskX - shift value is 16 bits, shifted is X
reg16SizeMask8 = reg8SizeMask8
reg16SizeMask16 = reg8SizeMask16
reg16SizeMask32 = reg8SizeMask32
reg16SizeMask64 = reg8SizeMask64
// reg32SizeMaskX - shift value is 32 bits, shifted is X
reg32SizeMask8 = reg8SizeMask8
reg32SizeMask16 = reg8SizeMask16
reg32SizeMask32 = reg8SizeMask32
reg32SizeMask64 = reg8SizeMask64
// reg64SizeMaskX - shift value is 64 bits, shifted is X
reg64SizeMask8 = reg8SizeMask8
reg64SizeMask16 = reg8SizeMask16
reg64SizeMask32 = reg8SizeMask32
reg64SizeMask64 = reg8SizeMask64
// regSizeMaskUintX - shift value is uint, shifted is X
regSizeMaskUint8 = reg8SizeMask8
regSizeMaskUint16 = reg8SizeMask16
regSizeMaskUint32 = reg8SizeMask32
regSizeMaskUint64 = reg8SizeMask64
)
Server/vendor/github.com/klauspost/compress/flate/regmask_other.go
Generated Vendored
+39
View File
@@ -0,0 +1,39 @@
//go:build !amd64
package flate
const (
// Masks for shifts with register sizes of the shift value.
// This can be used to work around the x86 design of shifting by mod register size.
// It can be used when a variable shift is always smaller than the register size.
// reg8SizeMaskX - shift value is 8 bits, shifted is X
reg8SizeMask8 = 0xff
reg8SizeMask16 = 0xff
reg8SizeMask32 = 0xff
reg8SizeMask64 = 0xff
// reg16SizeMaskX - shift value is 16 bits, shifted is X
reg16SizeMask8 = 0xffff
reg16SizeMask16 = 0xffff
reg16SizeMask32 = 0xffff
reg16SizeMask64 = 0xffff
// reg32SizeMaskX - shift value is 32 bits, shifted is X
reg32SizeMask8 = 0xffffffff
reg32SizeMask16 = 0xffffffff
reg32SizeMask32 = 0xffffffff
reg32SizeMask64 = 0xffffffff
// reg64SizeMaskX - shift value is 64 bits, shifted is X
reg64SizeMask8 = 0xffffffffffffffff
reg64SizeMask16 = 0xffffffffffffffff
reg64SizeMask32 = 0xffffffffffffffff
reg64SizeMask64 = 0xffffffffffffffff
// regSizeMaskUintX - shift value is uint, shifted is X
regSizeMaskUint8 = ^uint(0)
regSizeMaskUint16 = ^uint(0)
regSizeMaskUint32 = ^uint(0)
regSizeMaskUint64 = ^uint(0)
)
Server/vendor/github.com/klauspost/compress/flate/stateless.go
Generated Vendored
+325
View File
@@ -0,0 +1,325 @@
package flate
import (
"io"
"math"
"sync"
"github.com/klauspost/compress/internal/le"
)
const (
maxStatelessBlock = math.MaxInt16
// dictionary will be taken from maxStatelessBlock, so limit it.
maxStatelessDict = 8 << 10
slTableBits = 13
slTableSize = 1 << slTableBits
slTableShift = 32 - slTableBits
)
type statelessWriter struct {
dst io.Writer
closed bool
}
func (s *statelessWriter) Close() error {
if s.closed {
return nil
}
s.closed = true
// Emit EOF block
return StatelessDeflate(s.dst, nil, true, nil)
}
func (s *statelessWriter) Write(p []byte) (n int, err error) {
err = StatelessDeflate(s.dst, p, false, nil)
if err != nil {
return 0, err
}
return len(p), nil
}
func (s *statelessWriter) Reset(w io.Writer) {
s.dst = w
s.closed = false
}
// NewStatelessWriter will do compression but without maintaining any state
// between Write calls.
// There will be no memory kept between Write calls,
// but compression and speed will be suboptimal.
// Because of this, the size of actual Write calls will affect output size.
func NewStatelessWriter(dst io.Writer) io.WriteCloser {
return &statelessWriter{dst: dst}
}
// bitWriterPool contains bit writers that can be reused.
var bitWriterPool = sync.Pool{
New: func() any {
return newHuffmanBitWriter(nil)
},
}
// tokensPool contains tokens struct objects that can be reused
var tokensPool = sync.Pool{
New: func() any {
return &tokens{}
},
}
// StatelessDeflate allows compressing directly to a Writer without retaining state.
// When returning everything will be flushed.
// Up to 8KB of an optional dictionary can be given which is presumed to precede the block.
// Longer dictionaries will be truncated and will still produce valid output.
// Sending nil dictionary is perfectly fine.
func StatelessDeflate(out io.Writer, in []byte, eof bool, dict []byte) error {
bw := bitWriterPool.Get().(*huffmanBitWriter)
bw.reset(out)
defer func() {
// don't keep a reference to our output
bw.reset(nil)
bitWriterPool.Put(bw)
}()
if eof && len(in) == 0 {
// Just write an EOF block.
// Could be faster...
bw.writeStoredHeader(0, true)
bw.flush()
return bw.err
}
// Truncate dict
if len(dict) > maxStatelessDict {
dict = dict[len(dict)-maxStatelessDict:]
}
// For subsequent loops, keep shallow dict reference to avoid alloc+copy.
var inDict []byte
dst := tokensPool.Get().(*tokens)
dst.Reset()
defer func() {
tokensPool.Put(dst)
}()
for len(in) > 0 {
todo := in
if len(inDict) > 0 {
if len(todo) > maxStatelessBlock-maxStatelessDict {
todo = todo[:maxStatelessBlock-maxStatelessDict]
}
} else if len(todo) > maxStatelessBlock-len(dict) {
todo = todo[:maxStatelessBlock-len(dict)]
}
inOrg := in
in = in[len(todo):]
uncompressed := todo
if len(dict) > 0 {
// combine dict and source
bufLen := len(todo) + len(dict)
combined := make([]byte, bufLen)
copy(combined, dict)
copy(combined[len(dict):], todo)
todo = combined
}
// Compress
if len(inDict) == 0 {
statelessEnc(dst, todo, int16(len(dict)))
} else {
statelessEnc(dst, inDict[:maxStatelessDict+len(todo)], maxStatelessDict)
}
isEof := eof && len(in) == 0
if dst.n == 0 {
bw.writeStoredHeader(len(uncompressed), isEof)
if bw.err != nil {
return bw.err
}
bw.writeBytes(uncompressed)
} else if int(dst.n) > len(uncompressed)-len(uncompressed)>>4 {
// If we removed less than 1/16th, huffman compress the block.
bw.writeBlockHuff(isEof, uncompressed, len(in) == 0)
} else {
bw.writeBlockDynamic(dst, isEof, uncompressed, len(in) == 0)
}
if len(in) > 0 {
// Retain a dict if we have more
inDict = inOrg[len(uncompressed)-maxStatelessDict:]
dict = nil
dst.Reset()
}
if bw.err != nil {
return bw.err
}
}
if !eof {
// Align, only a stored block can do that.
bw.writeStoredHeader(0, false)
}
bw.flush()
return bw.err
}
func hashSL(u uint32) uint32 {
return (u * 0x1e35a7bd) >> slTableShift
}
func load3216(b []byte, i int16) uint32 {
return le.Load32(b, i)
}
func load6416(b []byte, i int16) uint64 {
return le.Load64(b, i)
}
func statelessEnc(dst *tokens, src []byte, startAt int16) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
)
type tableEntry struct {
offset int16
}
var table [slTableSize]tableEntry
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src)-int(startAt) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = 0
return
}
// Index until startAt
if startAt > 0 {
cv := load3232(src, 0)
for i := range startAt {
table[hashSL(cv)] = tableEntry{offset: i}
cv = (cv >> 8) | (uint32(src[i+4]) << 24)
}
}
s := startAt + 1
nextEmit := startAt
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := int16(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load3216(src, s)
for {
const skipLog = 5
const doEvery = 2
nextS := s
var candidate tableEntry
for {
nextHash := hashSL(cv)
candidate = table[nextHash]
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit || nextS <= 0 {
goto emitRemainder
}
now := load6416(src, nextS)
table[nextHash] = tableEntry{offset: s}
nextHash = hashSL(uint32(now))
if cv == load3216(src, candidate.offset) {
table[nextHash] = tableEntry{offset: nextS}
break
}
// Do one right away...
cv = uint32(now)
s = nextS
nextS++
candidate = table[nextHash]
now >>= 8
table[nextHash] = tableEntry{offset: s}
if cv == load3216(src, candidate.offset) {
table[nextHash] = tableEntry{offset: nextS}
break
}
cv = uint32(now)
s = nextS
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
for {
// Invariant: we have a 4-byte match at s, and no need to emit any
// literal bytes prior to s.
// Extend the 4-byte match as long as possible.
t := candidate.offset
l := int16(matchLen(src[s+4:], src[t+4:]) + 4)
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
// Save the match found
dst.AddMatchLong(int32(l), uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
goto emitRemainder
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-2 and at s. If
// another emitCopy is not our next move, also calculate nextHash
// at s+1. At least on GOARCH=amd64, these three hash calculations
// are faster as one load64 call (with some shifts) instead of
// three load32 calls.
x := load6416(src, s-2)
o := s - 2
prevHash := hashSL(uint32(x))
table[prevHash] = tableEntry{offset: o}
x >>= 16
currHash := hashSL(uint32(x))
candidate = table[currHash]
table[currHash] = tableEntry{offset: o + 2}
if uint32(x) != load3216(src, candidate.offset) {
cv = uint32(x >> 8)
s++
break
}
}
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}
Server/vendor/github.com/klauspost/compress/flate/token.go
Generated Vendored
+379
View File
@@ -0,0 +1,379 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
import (
"bytes"
"encoding/binary"
"fmt"
"io"
"math"
)
const (
// bits 0-16 xoffset = offset - MIN_OFFSET_SIZE, or literal - 16 bits
// bits 16-22 offsetcode - 5 bits
// bits 22-30 xlength = length - MIN_MATCH_LENGTH - 8 bits
// bits 30-32 type 0 = literal 1=EOF 2=Match 3=Unused - 2 bits
lengthShift = 22
offsetMask = 1<<lengthShift - 1
typeMask = 3 << 30
literalType = 0 << 30
matchType = 1 << 30
matchOffsetOnlyMask = 0xffff
)
// The length code for length X (MIN_MATCH_LENGTH <= X <= MAX_MATCH_LENGTH)
// is lengthCodes[length - MIN_MATCH_LENGTH]
var lengthCodes = [256]uint8{
0, 1, 2, 3, 4, 5, 6, 7, 8, 8,
9, 9, 10, 10, 11, 11, 12, 12, 12, 12,
13, 13, 13, 13, 14, 14, 14, 14, 15, 15,
15, 15, 16, 16, 16, 16, 16, 16, 16, 16,
17, 17, 17, 17, 17, 17, 17, 17, 18, 18,
18, 18, 18, 18, 18, 18, 19, 19, 19, 19,
19, 19, 19, 19, 20, 20, 20, 20, 20, 20,
20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
21, 21, 21, 21, 21, 21, 22, 22, 22, 22,
22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
22, 22, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 23, 23, 23, 23, 23, 23, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 28,
}
// lengthCodes1 is length codes, but starting at 1.
var lengthCodes1 = [256]uint8{
1, 2, 3, 4, 5, 6, 7, 8, 9, 9,
10, 10, 11, 11, 12, 12, 13, 13, 13, 13,
14, 14, 14, 14, 15, 15, 15, 15, 16, 16,
16, 16, 17, 17, 17, 17, 17, 17, 17, 17,
18, 18, 18, 18, 18, 18, 18, 18, 19, 19,
19, 19, 19, 19, 19, 19, 20, 20, 20, 20,
20, 20, 20, 20, 21, 21, 21, 21, 21, 21,
21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
22, 22, 22, 22, 22, 22, 23, 23, 23, 23,
23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 29,
}
var offsetCodes = [256]uint32{
0, 1, 2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7,
8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9,
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
}
// offsetCodes14 are offsetCodes, but with 14 added.
var offsetCodes14 = [256]uint32{
14, 15, 16, 17, 18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21,
22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
}
type token uint32
type tokens struct {
extraHist [32]uint16 // codes 256->maxnumlit
offHist [32]uint16 // offset codes
litHist [256]uint16 // codes 0->255
nFilled int
n uint16 // Must be able to contain maxStoreBlockSize
tokens [maxStoreBlockSize + 1]token
}
func (t *tokens) Reset() {
if t.n == 0 {
return
}
t.n = 0
t.nFilled = 0
for i := range t.litHist[:] {
t.litHist[i] = 0
}
for i := range t.extraHist[:] {
t.extraHist[i] = 0
}
for i := range t.offHist[:] {
t.offHist[i] = 0
}
}
func (t *tokens) Fill() {
if t.n == 0 {
return
}
for i, v := range t.litHist[:] {
if v == 0 {
t.litHist[i] = 1
t.nFilled++
}
}
for i, v := range t.extraHist[:literalCount-256] {
if v == 0 {
t.nFilled++
t.extraHist[i] = 1
}
}
for i, v := range t.offHist[:offsetCodeCount] {
if v == 0 {
t.offHist[i] = 1
}
}
}
func indexTokens(in []token) tokens {
var t tokens
t.indexTokens(in)
return t
}
func (t *tokens) indexTokens(in []token) {
t.Reset()
for _, tok := range in {
if tok < matchType {
t.AddLiteral(tok.literal())
continue
}
t.AddMatch(uint32(tok.length()), tok.offset()&matchOffsetOnlyMask)
}
}
// emitLiteral writes a literal chunk and returns the number of bytes written.
func emitLiteral(dst *tokens, lit []byte) {
for _, v := range lit {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
func (t *tokens) AddLiteral(lit byte) {
t.tokens[t.n] = token(lit)
t.litHist[lit]++
t.n++
}
// from https://stackoverflow.com/a/28730362
func mFastLog2(val float32) float32 {
ux := int32(math.Float32bits(val))
log2 := (float32)(((ux >> 23) & 255) - 128)
ux &= -0x7f800001
ux += 127 << 23
uval := math.Float32frombits(uint32(ux))
log2 += ((-0.34484843)*uval+2.02466578)*uval - 0.67487759
return log2
}
// EstimatedBits will return an minimum size estimated by an *optimal*
// compression of the block.
// The size of the block
func (t *tokens) EstimatedBits() int {
shannon := float32(0)
bits := int(0)
nMatches := 0
total := int(t.n) + t.nFilled
if total > 0 {
invTotal := 1.0 / float32(total)
for _, v := range t.litHist[:] {
if v > 0 {
n := float32(v)
shannon += atLeastOne(-mFastLog2(n*invTotal)) * n
}
}
// Just add 15 for EOB
shannon += 15
for i, v := range t.extraHist[1 : literalCount-256] {
if v > 0 {
n := float32(v)
shannon += atLeastOne(-mFastLog2(n*invTotal)) * n
bits += int(lengthExtraBits[i&31]) * int(v)
nMatches += int(v)
}
}
}
if nMatches > 0 {
invTotal := 1.0 / float32(nMatches)
for i, v := range t.offHist[:offsetCodeCount] {
if v > 0 {
n := float32(v)
shannon += atLeastOne(-mFastLog2(n*invTotal)) * n
bits += int(offsetExtraBits[i&31]) * int(v)
}
}
}
return int(shannon) + bits
}
// AddMatch adds a match to the tokens.
// This function is very sensitive to inlining and right on the border.
func (t *tokens) AddMatch(xlength uint32, xoffset uint32) {
if debugDeflate {
if xlength >= maxMatchLength+baseMatchLength {
panic(fmt.Errorf("invalid length: %v", xlength))
}
if xoffset >= maxMatchOffset+baseMatchOffset {
panic(fmt.Errorf("invalid offset: %v", xoffset))
}
}
oCode := offsetCode(xoffset)
xoffset |= oCode << 16
t.extraHist[lengthCodes1[uint8(xlength)]]++
t.offHist[oCode&31]++
t.tokens[t.n] = token(matchType | xlength<<lengthShift | xoffset)
t.n++
}
// AddMatchLong adds a match to the tokens, potentially longer than max match length.
// Length should NOT have the base subtracted, only offset should.
func (t *tokens) AddMatchLong(xlength int32, xoffset uint32) {
if debugDeflate {
if xoffset >= maxMatchOffset+baseMatchOffset {
panic(fmt.Errorf("invalid offset: %v", xoffset))
}
}
oc := offsetCode(xoffset)
xoffset |= oc << 16
for xlength > 0 {
xl := xlength
if xl > 258 {
// We need to have at least baseMatchLength left over for next loop.
if xl > 258+baseMatchLength {
xl = 258
} else {
xl = 258 - baseMatchLength
}
}
xlength -= xl
xl -= baseMatchLength
t.extraHist[lengthCodes1[uint8(xl)]]++
t.offHist[oc&31]++
t.tokens[t.n] = token(matchType | uint32(xl)<<lengthShift | xoffset)
t.n++
}
}
func (t *tokens) AddEOB() {
t.tokens[t.n] = token(endBlockMarker)
t.extraHist[0]++
t.n++
}
func (t *tokens) Slice() []token {
return t.tokens[:t.n]
}
// VarInt returns the tokens as varint encoded bytes.
func (t *tokens) VarInt() []byte {
var b = make([]byte, binary.MaxVarintLen32*int(t.n))
var off int
for _, v := range t.tokens[:t.n] {
off += binary.PutUvarint(b[off:], uint64(v))
}
return b[:off]
}
// FromVarInt restores t to the varint encoded tokens provided.
// Any data in t is removed.
func (t *tokens) FromVarInt(b []byte) error {
var buf = bytes.NewReader(b)
var toks []token
for {
r, err := binary.ReadUvarint(buf)
if err == io.EOF {
break
}
if err != nil {
return err
}
toks = append(toks, token(r))
}
t.indexTokens(toks)
return nil
}
// Returns the type of a token
func (t token) typ() uint32 { return uint32(t) & typeMask }
// Returns the literal of a literal token
func (t token) literal() uint8 { return uint8(t) }
// Returns the extra offset of a match token
func (t token) offset() uint32 { return uint32(t) & offsetMask }
func (t token) length() uint8 { return uint8(t >> lengthShift) }
// Convert length to code.
func lengthCode(len uint8) uint8 { return lengthCodes[len] }
// Returns the offset code corresponding to a specific offset
func offsetCode(off uint32) uint32 {
if false {
if off < uint32(len(offsetCodes)) {
return offsetCodes[off&255]
} else if off>>7 < uint32(len(offsetCodes)) {
return offsetCodes[(off>>7)&255] + 14
} else {
return offsetCodes[(off>>14)&255] + 28
}
}
if off < uint32(len(offsetCodes)) {
return offsetCodes[uint8(off)]
}
return offsetCodes14[uint8(off>>7)]
}
Server/vendor/github.com/klauspost/compress/fse/README.md
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# Finite State Entropy
This package provides Finite State Entropy encoding and decoding.
Finite State Entropy (also referenced as [tANS](https://en.wikipedia.org/wiki/Asymmetric_numeral_systems#tANS))
encoding provides a fast near-optimal symbol encoding/decoding
for byte blocks as implemented in [zstandard](https://github.com/facebook/zstd).
This can be used for compressing input with a lot of similar input values to the smallest number of bytes.
This does not perform any multi-byte [dictionary coding](https://en.wikipedia.org/wiki/Dictionary_coder) as LZ coders,
but it can be used as a secondary step to compressors (like Snappy) that does not do entropy encoding.
* [Godoc documentation](https://godoc.org/github.com/klauspost/compress/fse)
## News
* Feb 2018: First implementation released. Consider this beta software for now.
# Usage
This package provides a low level interface that allows to compress single independent blocks.
Each block is separate, and there is no built in integrity checks.
This means that the caller should keep track of block sizes and also do checksums if needed.
Compressing a block is done via the [`Compress`](https://godoc.org/github.com/klauspost/compress/fse#Compress) function.
You must provide input and will receive the output and maybe an error.
These error values can be returned:
| Error | Description |
|---------------------|-----------------------------------------------------------------------------|
| `<nil>` | Everything ok, output is returned |
| `ErrIncompressible` | Returned when input is judged to be too hard to compress |
| `ErrUseRLE` | Returned from the compressor when the input is a single byte value repeated |
| `(error)` | An internal error occurred. |
As can be seen above there are errors that will be returned even under normal operation so it is important to handle these.
To reduce allocations you can provide a [`Scratch`](https://godoc.org/github.com/klauspost/compress/fse#Scratch) object
that can be re-used for successive calls. Both compression and decompression accepts a `Scratch` object, and the same
object can be used for both.
Be aware, that when re-using a `Scratch` object that the *output* buffer is also re-used, so if you are still using this
you must set the `Out` field in the scratch to nil. The same buffer is used for compression and decompression output.
Decompressing is done by calling the [`Decompress`](https://godoc.org/github.com/klauspost/compress/fse#Decompress) function.
You must provide the output from the compression stage, at exactly the size you got back. If you receive an error back
your input was likely corrupted.
It is important to note that a successful decoding does *not* mean your output matches your original input.
There are no integrity checks, so relying on errors from the decompressor does not assure your data is valid.
For more detailed usage, see examples in the [godoc documentation](https://godoc.org/github.com/klauspost/compress/fse#pkg-examples).
# Performance
A lot of factors are affecting speed. Block sizes and compressibility of the material are primary factors.
All compression functions are currently only running on the calling goroutine so only one core will be used per block.
The compressor is significantly faster if symbols are kept as small as possible. The highest byte value of the input
is used to reduce some of the processing, so if all your input is above byte value 64 for instance, it may be
beneficial to transpose all your input values down by 64.
With moderate block sizes around 64k speed are typically 200MB/s per core for compression and
around 300MB/s decompression speed.
The same hardware typically does Huffman (deflate) encoding at 125MB/s and decompression at 100MB/s.
# Plans
At one point, more internals will be exposed to facilitate more "expert" usage of the components.
A streaming interface is also likely to be implemented. Likely compatible with [FSE stream format](https://github.com/Cyan4973/FiniteStateEntropy/blob/dev/programs/fileio.c#L261).
# Contributing
Contributions are always welcome. Be aware that adding public functions will require good justification and breaking
changes will likely not be accepted. If in doubt open an issue before writing the PR.
Server/vendor/github.com/klauspost/compress/fse/bitreader.go
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// Copyright 2018 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
package fse
import (
"encoding/binary"
"errors"
"io"
)
// bitReader reads a bitstream in reverse.
// The last set bit indicates the start of the stream and is used
// for aligning the input.
type bitReader struct {
in []byte
off uint // next byte to read is at in[off - 1]
value uint64
bitsRead uint8
}
// init initializes and resets the bit reader.
func (b *bitReader) init(in []byte) error {
if len(in) < 1 {
return errors.New("corrupt stream: too short")
}
b.in = in
b.off = uint(len(in))
// The highest bit of the last byte indicates where to start
v := in[len(in)-1]
if v == 0 {
return errors.New("corrupt stream, did not find end of stream")
}
b.bitsRead = 64
b.value = 0
if len(in) >= 8 {
b.fillFastStart()
} else {
b.fill()
b.fill()
}
b.bitsRead += 8 - uint8(highBits(uint32(v)))
return nil
}
// getBits will return n bits. n can be 0.
func (b *bitReader) getBits(n uint8) uint16 {
if n == 0 || b.bitsRead >= 64 {
return 0
}
return b.getBitsFast(n)
}
// getBitsFast requires that at least one bit is requested every time.
// There are no checks if the buffer is filled.
func (b *bitReader) getBitsFast(n uint8) uint16 {
const regMask = 64 - 1
v := uint16((b.value << (b.bitsRead & regMask)) >> ((regMask + 1 - n) & regMask))
b.bitsRead += n
return v
}
// fillFast() will make sure at least 32 bits are available.
// There must be at least 4 bytes available.
func (b *bitReader) fillFast() {
if b.bitsRead < 32 {
return
}
// 2 bounds checks.
v := b.in[b.off-4:]
v = v[:4]
low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
b.value = (b.value << 32) | uint64(low)
b.bitsRead -= 32
b.off -= 4
}
// fill() will make sure at least 32 bits are available.
func (b *bitReader) fill() {
if b.bitsRead < 32 {
return
}
if b.off > 4 {
v := b.in[b.off-4:]
v = v[:4]
low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
b.value = (b.value << 32) | uint64(low)
b.bitsRead -= 32
b.off -= 4
return
}
for b.off > 0 {
b.value = (b.value << 8) | uint64(b.in[b.off-1])
b.bitsRead -= 8
b.off--
}
}
// fillFastStart() assumes the bitreader is empty and there is at least 8 bytes to read.
func (b *bitReader) fillFastStart() {
// Do single re-slice to avoid bounds checks.
b.value = binary.LittleEndian.Uint64(b.in[b.off-8:])
b.bitsRead = 0
b.off -= 8
}
// finished returns true if all bits have been read from the bit stream.
func (b *bitReader) finished() bool {
return b.bitsRead >= 64 && b.off == 0
}
// close the bitstream and returns an error if out-of-buffer reads occurred.
func (b *bitReader) close() error {
// Release reference.
b.in = nil
if b.bitsRead > 64 {
return io.ErrUnexpectedEOF
}
return nil
}
Server/vendor/github.com/klauspost/compress/fse/bitwriter.go
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// Copyright 2018 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
package fse
import "fmt"
// bitWriter will write bits.
// First bit will be LSB of the first byte of output.
type bitWriter struct {
bitContainer uint64
nBits uint8
out []byte
}
// bitMask16 is bitmasks. Has extra to avoid bounds check.
var bitMask16 = [32]uint16{
0, 1, 3, 7, 0xF, 0x1F,
0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF,
0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF, 0xFFFF,
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
0xFFFF, 0xFFFF} /* up to 16 bits */
// addBits16NC will add up to 16 bits.
// It will not check if there is space for them,
// so the caller must ensure that it has flushed recently.
func (b *bitWriter) addBits16NC(value uint16, bits uint8) {
b.bitContainer |= uint64(value&bitMask16[bits&31]) << (b.nBits & 63)
b.nBits += bits
}
// addBits16Clean will add up to 16 bits. value may not contain more set bits than indicated.
// It will not check if there is space for them, so the caller must ensure that it has flushed recently.
func (b *bitWriter) addBits16Clean(value uint16, bits uint8) {
b.bitContainer |= uint64(value) << (b.nBits & 63)
b.nBits += bits
}
// addBits16ZeroNC will add up to 16 bits.
// It will not check if there is space for them,
// so the caller must ensure that it has flushed recently.
// This is fastest if bits can be zero.
func (b *bitWriter) addBits16ZeroNC(value uint16, bits uint8) {
if bits == 0 {
return
}
value <<= (16 - bits) & 15
value >>= (16 - bits) & 15
b.bitContainer |= uint64(value) << (b.nBits & 63)
b.nBits += bits
}
// flush will flush all pending full bytes.
// There will be at least 56 bits available for writing when this has been called.
// Using flush32 is faster, but leaves less space for writing.
func (b *bitWriter) flush() {
v := b.nBits >> 3
switch v {
case 0:
case 1:
b.out = append(b.out,
byte(b.bitContainer),
)
case 2:
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
)
case 3:
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
)
case 4:
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
byte(b.bitContainer>>24),
)
case 5:
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
byte(b.bitContainer>>24),
byte(b.bitContainer>>32),
)
case 6:
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
byte(b.bitContainer>>24),
byte(b.bitContainer>>32),
byte(b.bitContainer>>40),
)
case 7:
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
byte(b.bitContainer>>24),
byte(b.bitContainer>>32),
byte(b.bitContainer>>40),
byte(b.bitContainer>>48),
)
case 8:
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
byte(b.bitContainer>>24),
byte(b.bitContainer>>32),
byte(b.bitContainer>>40),
byte(b.bitContainer>>48),
byte(b.bitContainer>>56),
)
default:
panic(fmt.Errorf("bits (%d) > 64", b.nBits))
}
b.bitContainer >>= v << 3
b.nBits &= 7
}
// flush32 will flush out, so there are at least 32 bits available for writing.
func (b *bitWriter) flush32() {
if b.nBits < 32 {
return
}
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
byte(b.bitContainer>>24))
b.nBits -= 32
b.bitContainer >>= 32
}
// flushAlign will flush remaining full bytes and align to next byte boundary.
func (b *bitWriter) flushAlign() {
nbBytes := (b.nBits + 7) >> 3
for i := range nbBytes {
b.out = append(b.out, byte(b.bitContainer>>(i*8)))
}
b.nBits = 0
b.bitContainer = 0
}
// close will write the alignment bit and write the final byte(s)
// to the output.
func (b *bitWriter) close() {
// End mark
b.addBits16Clean(1, 1)
// flush until next byte.
b.flushAlign()
}
// reset and continue writing by appending to out.
func (b *bitWriter) reset(out []byte) {
b.bitContainer = 0
b.nBits = 0
b.out = out
}
Server/vendor/github.com/klauspost/compress/fse/bytereader.go
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// Copyright 2018 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
package fse
// byteReader provides a byte reader that reads
// little endian values from a byte stream.
// The input stream is manually advanced.
// The reader performs no bounds checks.
type byteReader struct {
b []byte
off int
}
// init will initialize the reader and set the input.
func (b *byteReader) init(in []byte) {
b.b = in
b.off = 0
}
// advance the stream b n bytes.
func (b *byteReader) advance(n uint) {
b.off += int(n)
}
// Uint32 returns a little endian uint32 starting at current offset.
func (b byteReader) Uint32() uint32 {
b2 := b.b[b.off:]
b2 = b2[:4]
v3 := uint32(b2[3])
v2 := uint32(b2[2])
v1 := uint32(b2[1])
v0 := uint32(b2[0])
return v0 | (v1 << 8) | (v2 << 16) | (v3 << 24)
}
// unread returns the unread portion of the input.
func (b byteReader) unread() []byte {
return b.b[b.off:]
}
// remain will return the number of bytes remaining.
func (b byteReader) remain() int {
return len(b.b) - b.off
}
Server/vendor/github.com/klauspost/compress/fse/compress.go
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// Copyright 2018 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
package fse
import (
"errors"
"fmt"
)
// Compress the input bytes. Input must be < 2GB.
// Provide a Scratch buffer to avoid memory allocations.
// Note that the output is also kept in the scratch buffer.
// If input is too hard to compress, ErrIncompressible is returned.
// If input is a single byte value repeated ErrUseRLE is returned.
func Compress(in []byte, s *Scratch) ([]byte, error) {
if len(in) <= 1 {
return nil, ErrIncompressible
}
if len(in) > (2<<30)-1 {
return nil, errors.New("input too big, must be < 2GB")
}
s, err := s.prepare(in)
if err != nil {
return nil, err
}
// Create histogram, if none was provided.
maxCount := s.maxCount
if maxCount == 0 {
maxCount = s.countSimple(in)
}
// Reset for next run.
s.clearCount = true
s.maxCount = 0
if maxCount == len(in) {
// One symbol, use RLE
return nil, ErrUseRLE
}
if maxCount == 1 || maxCount < (len(in)>>7) {
// Each symbol present maximum once or too well distributed.
return nil, ErrIncompressible
}
s.optimalTableLog()
err = s.normalizeCount()
if err != nil {
return nil, err
}
err = s.writeCount()
if err != nil {
return nil, err
}
if false {
err = s.validateNorm()
if err != nil {
return nil, err
}
}
err = s.buildCTable()
if err != nil {
return nil, err
}
err = s.compress(in)
if err != nil {
return nil, err
}
s.Out = s.bw.out
// Check if we compressed.
if len(s.Out) >= len(in) {
return nil, ErrIncompressible
}
return s.Out, nil
}
// cState contains the compression state of a stream.
type cState struct {
bw *bitWriter
stateTable []uint16
state uint16
}
// init will initialize the compression state to the first symbol of the stream.
func (c *cState) init(bw *bitWriter, ct *cTable, tableLog uint8, first symbolTransform) {
c.bw = bw
c.stateTable = ct.stateTable
nbBitsOut := (first.deltaNbBits + (1 << 15)) >> 16
im := int32((nbBitsOut << 16) - first.deltaNbBits)
lu := (im >> nbBitsOut) + first.deltaFindState
c.state = c.stateTable[lu]
}
// encode the output symbol provided and write it to the bitstream.
func (c *cState) encode(symbolTT symbolTransform) {
nbBitsOut := (uint32(c.state) + symbolTT.deltaNbBits) >> 16
dstState := int32(c.state>>(nbBitsOut&15)) + symbolTT.deltaFindState
c.bw.addBits16NC(c.state, uint8(nbBitsOut))
c.state = c.stateTable[dstState]
}
// encode the output symbol provided and write it to the bitstream.
func (c *cState) encodeZero(symbolTT symbolTransform) {
nbBitsOut := (uint32(c.state) + symbolTT.deltaNbBits) >> 16
dstState := int32(c.state>>(nbBitsOut&15)) + symbolTT.deltaFindState
c.bw.addBits16ZeroNC(c.state, uint8(nbBitsOut))
c.state = c.stateTable[dstState]
}
// flush will write the tablelog to the output and flush the remaining full bytes.
func (c *cState) flush(tableLog uint8) {
c.bw.flush32()
c.bw.addBits16NC(c.state, tableLog)
c.bw.flush()
}
// compress is the main compression loop that will encode the input from the last byte to the first.
func (s *Scratch) compress(src []byte) error {
if len(src) <= 2 {
return errors.New("compress: src too small")
}
tt := s.ct.symbolTT[:256]
s.bw.reset(s.Out)
// Our two states each encodes every second byte.
// Last byte encoded (first byte decoded) will always be encoded by c1.
var c1, c2 cState
// Encode so remaining size is divisible by 4.
ip := len(src)
if ip&1 == 1 {
c1.init(&s.bw, &s.ct, s.actualTableLog, tt[src[ip-1]])
c2.init(&s.bw, &s.ct, s.actualTableLog, tt[src[ip-2]])
c1.encodeZero(tt[src[ip-3]])
ip -= 3
} else {
c2.init(&s.bw, &s.ct, s.actualTableLog, tt[src[ip-1]])
c1.init(&s.bw, &s.ct, s.actualTableLog, tt[src[ip-2]])
ip -= 2
}
if ip&2 != 0 {
c2.encodeZero(tt[src[ip-1]])
c1.encodeZero(tt[src[ip-2]])
ip -= 2
}
src = src[:ip]
// Main compression loop.
switch {
case !s.zeroBits && s.actualTableLog <= 8:
// We can encode 4 symbols without requiring a flush.
// We do not need to check if any output is 0 bits.
for ; len(src) >= 4; src = src[:len(src)-4] {
s.bw.flush32()
v3, v2, v1, v0 := src[len(src)-4], src[len(src)-3], src[len(src)-2], src[len(src)-1]
c2.encode(tt[v0])
c1.encode(tt[v1])
c2.encode(tt[v2])
c1.encode(tt[v3])
}
case !s.zeroBits:
// We do not need to check if any output is 0 bits.
for ; len(src) >= 4; src = src[:len(src)-4] {
s.bw.flush32()
v3, v2, v1, v0 := src[len(src)-4], src[len(src)-3], src[len(src)-2], src[len(src)-1]
c2.encode(tt[v0])
c1.encode(tt[v1])
s.bw.flush32()
c2.encode(tt[v2])
c1.encode(tt[v3])
}
case s.actualTableLog <= 8:
// We can encode 4 symbols without requiring a flush
for ; len(src) >= 4; src = src[:len(src)-4] {
s.bw.flush32()
v3, v2, v1, v0 := src[len(src)-4], src[len(src)-3], src[len(src)-2], src[len(src)-1]
c2.encodeZero(tt[v0])
c1.encodeZero(tt[v1])
c2.encodeZero(tt[v2])
c1.encodeZero(tt[v3])
}
default:
for ; len(src) >= 4; src = src[:len(src)-4] {
s.bw.flush32()
v3, v2, v1, v0 := src[len(src)-4], src[len(src)-3], src[len(src)-2], src[len(src)-1]
c2.encodeZero(tt[v0])
c1.encodeZero(tt[v1])
s.bw.flush32()
c2.encodeZero(tt[v2])
c1.encodeZero(tt[v3])
}
}
// Flush final state.
// Used to initialize state when decoding.
c2.flush(s.actualTableLog)
c1.flush(s.actualTableLog)
s.bw.close()
return nil
}
// writeCount will write the normalized histogram count to header.
// This is read back by readNCount.
func (s *Scratch) writeCount() error {
var (
tableLog = s.actualTableLog
tableSize = 1 << tableLog
previous0 bool
charnum uint16
maxHeaderSize = ((int(s.symbolLen)*int(tableLog) + 4 + 2) >> 3) + 3
// Write Table Size
bitStream = uint32(tableLog - minTablelog)
bitCount = uint(4)
remaining = int16(tableSize + 1) /* +1 for extra accuracy */
threshold = int16(tableSize)
nbBits = uint(tableLog + 1)
)
if cap(s.Out) < maxHeaderSize {
s.Out = make([]byte, 0, s.br.remain()+maxHeaderSize)
}
outP := uint(0)
out := s.Out[:maxHeaderSize]
// stops at 1
for remaining > 1 {
if previous0 {
start := charnum
for s.norm[charnum] == 0 {
charnum++
}
for charnum >= start+24 {
start += 24
bitStream += uint32(0xFFFF) << bitCount
out[outP] = byte(bitStream)
out[outP+1] = byte(bitStream >> 8)
outP += 2
bitStream >>= 16
}
for charnum >= start+3 {
start += 3
bitStream += 3 << bitCount
bitCount += 2
}
bitStream += uint32(charnum-start) << bitCount
bitCount += 2
if bitCount > 16 {
out[outP] = byte(bitStream)
out[outP+1] = byte(bitStream >> 8)
outP += 2
bitStream >>= 16
bitCount -= 16
}
}
count := s.norm[charnum]
charnum++
max := (2*threshold - 1) - remaining
if count < 0 {
remaining += count
} else {
remaining -= count
}
count++ // +1 for extra accuracy
if count >= threshold {
count += max // [0..max[ [max..threshold[ (...) [threshold+max 2*threshold[
}
bitStream += uint32(count) << bitCount
bitCount += nbBits
if count < max {
bitCount--
}
previous0 = count == 1
if remaining < 1 {
return errors.New("internal error: remaining<1")
}
for remaining < threshold {
nbBits--
threshold >>= 1
}
if bitCount > 16 {
out[outP] = byte(bitStream)
out[outP+1] = byte(bitStream >> 8)
outP += 2
bitStream >>= 16
bitCount -= 16
}
}
out[outP] = byte(bitStream)
out[outP+1] = byte(bitStream >> 8)
outP += (bitCount + 7) / 8
if charnum > s.symbolLen {
return errors.New("internal error: charnum > s.symbolLen")
}
s.Out = out[:outP]
return nil
}
// symbolTransform contains the state transform for a symbol.
type symbolTransform struct {
deltaFindState int32
deltaNbBits uint32
}
// String prints values as a human readable string.
func (s symbolTransform) String() string {
return fmt.Sprintf("dnbits: %08x, fs:%d", s.deltaNbBits, s.deltaFindState)
}
// cTable contains tables used for compression.
type cTable struct {
tableSymbol []byte
stateTable []uint16
symbolTT []symbolTransform
}
// allocCtable will allocate tables needed for compression.
// If existing tables a re big enough, they are simply re-used.
func (s *Scratch) allocCtable() {
tableSize := 1 << s.actualTableLog
// get tableSymbol that is big enough.
if cap(s.ct.tableSymbol) < tableSize {
s.ct.tableSymbol = make([]byte, tableSize)
}
s.ct.tableSymbol = s.ct.tableSymbol[:tableSize]
ctSize := tableSize
if cap(s.ct.stateTable) < ctSize {
s.ct.stateTable = make([]uint16, ctSize)
}
s.ct.stateTable = s.ct.stateTable[:ctSize]
if cap(s.ct.symbolTT) < 256 {
s.ct.symbolTT = make([]symbolTransform, 256)
}
s.ct.symbolTT = s.ct.symbolTT[:256]
}
// buildCTable will populate the compression table so it is ready to be used.
func (s *Scratch) buildCTable() error {
tableSize := uint32(1 << s.actualTableLog)
highThreshold := tableSize - 1
var cumul [maxSymbolValue + 2]int16
s.allocCtable()
tableSymbol := s.ct.tableSymbol[:tableSize]
// symbol start positions
{
cumul[0] = 0
for ui, v := range s.norm[:s.symbolLen-1] {
u := byte(ui) // one less than reference
if v == -1 {
// Low proba symbol
cumul[u+1] = cumul[u] + 1
tableSymbol[highThreshold] = u
highThreshold--
} else {
cumul[u+1] = cumul[u] + v
}
}
// Encode last symbol separately to avoid overflowing u
u := int(s.symbolLen - 1)
v := s.norm[s.symbolLen-1]
if v == -1 {
// Low proba symbol
cumul[u+1] = cumul[u] + 1
tableSymbol[highThreshold] = byte(u)
highThreshold--
} else {
cumul[u+1] = cumul[u] + v
}
if uint32(cumul[s.symbolLen]) != tableSize {
return fmt.Errorf("internal error: expected cumul[s.symbolLen] (%d) == tableSize (%d)", cumul[s.symbolLen], tableSize)
}
cumul[s.symbolLen] = int16(tableSize) + 1
}
// Spread symbols
s.zeroBits = false
{
step := tableStep(tableSize)
tableMask := tableSize - 1
var position uint32
// if any symbol > largeLimit, we may have 0 bits output.
largeLimit := int16(1 << (s.actualTableLog - 1))
for ui, v := range s.norm[:s.symbolLen] {
symbol := byte(ui)
if v > largeLimit {
s.zeroBits = true
}
for range v {
tableSymbol[position] = symbol
position = (position + step) & tableMask
for position > highThreshold {
position = (position + step) & tableMask
} /* Low proba area */
}
}
// Check if we have gone through all positions
if position != 0 {
return errors.New("position!=0")
}
}
// Build table
table := s.ct.stateTable
{
tsi := int(tableSize)
for u, v := range tableSymbol {
// TableU16 : sorted by symbol order; gives next state value
table[cumul[v]] = uint16(tsi + u)
cumul[v]++
}
}
// Build Symbol Transformation Table
{
total := int16(0)
symbolTT := s.ct.symbolTT[:s.symbolLen]
tableLog := s.actualTableLog
tl := (uint32(tableLog) << 16) - (1 << tableLog)
for i, v := range s.norm[:s.symbolLen] {
switch v {
case 0:
case -1, 1:
symbolTT[i].deltaNbBits = tl
symbolTT[i].deltaFindState = int32(total - 1)
total++
default:
maxBitsOut := uint32(tableLog) - highBits(uint32(v-1))
minStatePlus := uint32(v) << maxBitsOut
symbolTT[i].deltaNbBits = (maxBitsOut << 16) - minStatePlus
symbolTT[i].deltaFindState = int32(total - v)
total += v
}
}
if total != int16(tableSize) {
return fmt.Errorf("total mismatch %d (got) != %d (want)", total, tableSize)
}
}
return nil
}
// countSimple will create a simple histogram in s.count.
// Returns the biggest count.
// Does not update s.clearCount.
func (s *Scratch) countSimple(in []byte) (max int) {
for _, v := range in {
s.count[v]++
}
m, symlen := uint32(0), s.symbolLen
for i, v := range s.count[:] {
if v == 0 {
continue
}
if v > m {
m = v
}
symlen = uint16(i) + 1
}
s.symbolLen = symlen
return int(m)
}
// minTableLog provides the minimum logSize to safely represent a distribution.
func (s *Scratch) minTableLog() uint8 {
minBitsSrc := highBits(uint32(s.br.remain()-1)) + 1
minBitsSymbols := highBits(uint32(s.symbolLen-1)) + 2
if minBitsSrc < minBitsSymbols {
return uint8(minBitsSrc)
}
return uint8(minBitsSymbols)
}
// optimalTableLog calculates and sets the optimal tableLog in s.actualTableLog
func (s *Scratch) optimalTableLog() {
tableLog := s.TableLog
minBits := s.minTableLog()
maxBitsSrc := uint8(highBits(uint32(s.br.remain()-1))) - 2
if maxBitsSrc < tableLog {
// Accuracy can be reduced
tableLog = maxBitsSrc
}
if minBits > tableLog {
tableLog = minBits
}
// Need a minimum to safely represent all symbol values
if tableLog < minTablelog {
tableLog = minTablelog
}
if tableLog > maxTableLog {
tableLog = maxTableLog
}
s.actualTableLog = tableLog
}
var rtbTable = [...]uint32{0, 473195, 504333, 520860, 550000, 700000, 750000, 830000}
// normalizeCount will normalize the count of the symbols so
// the total is equal to the table size.
func (s *Scratch) normalizeCount() error {
var (
tableLog = s.actualTableLog
scale = 62 - uint64(tableLog)
step = (1 << 62) / uint64(s.br.remain())
vStep = uint64(1) << (scale - 20)
stillToDistribute = int16(1 << tableLog)
largest int
largestP int16
lowThreshold = (uint32)(s.br.remain() >> tableLog)
)
for i, cnt := range s.count[:s.symbolLen] {
// already handled
// if (count[s] == s.length) return 0; /* rle special case */
if cnt == 0 {
s.norm[i] = 0
continue
}
if cnt <= lowThreshold {
s.norm[i] = -1
stillToDistribute--
} else {
proba := (int16)((uint64(cnt) * step) >> scale)
if proba < 8 {
restToBeat := vStep * uint64(rtbTable[proba])
v := uint64(cnt)*step - (uint64(proba) << scale)
if v > restToBeat {
proba++
}
}
if proba > largestP {
largestP = proba
largest = i
}
s.norm[i] = proba
stillToDistribute -= proba
}
}
if -stillToDistribute >= (s.norm[largest] >> 1) {
// corner case, need another normalization method
return s.normalizeCount2()
}
s.norm[largest] += stillToDistribute
return nil
}
// Secondary normalization method.
// To be used when primary method fails.
func (s *Scratch) normalizeCount2() error {
const notYetAssigned = -2
var (
distributed uint32
total = uint32(s.br.remain())
tableLog = s.actualTableLog
lowThreshold = total >> tableLog
lowOne = (total * 3) >> (tableLog + 1)
)
for i, cnt := range s.count[:s.symbolLen] {
if cnt == 0 {
s.norm[i] = 0
continue
}
if cnt <= lowThreshold {
s.norm[i] = -1
distributed++
total -= cnt
continue
}
if cnt <= lowOne {
s.norm[i] = 1
distributed++
total -= cnt
continue
}
s.norm[i] = notYetAssigned
}
toDistribute := (1 << tableLog) - distributed
if (total / toDistribute) > lowOne {
// risk of rounding to zero
lowOne = (total * 3) / (toDistribute * 2)
for i, cnt := range s.count[:s.symbolLen] {
if (s.norm[i] == notYetAssigned) && (cnt <= lowOne) {
s.norm[i] = 1
distributed++
total -= cnt
continue
}
}
toDistribute = (1 << tableLog) - distributed
}
if distributed == uint32(s.symbolLen)+1 {
// all values are pretty poor;
// probably incompressible data (should have already been detected);
// find max, then give all remaining points to max
var maxV int
var maxC uint32
for i, cnt := range s.count[:s.symbolLen] {
if cnt > maxC {
maxV = i
maxC = cnt
}
}
s.norm[maxV] += int16(toDistribute)
return nil
}
if total == 0 {
// all of the symbols were low enough for the lowOne or lowThreshold
for i := uint32(0); toDistribute > 0; i = (i + 1) % (uint32(s.symbolLen)) {
if s.norm[i] > 0 {
toDistribute--
s.norm[i]++
}
}
return nil
}
var (
vStepLog = 62 - uint64(tableLog)
mid = uint64((1 << (vStepLog - 1)) - 1)
rStep = (((1 << vStepLog) * uint64(toDistribute)) + mid) / uint64(total) // scale on remaining
tmpTotal = mid
)
for i, cnt := range s.count[:s.symbolLen] {
if s.norm[i] == notYetAssigned {
var (
end = tmpTotal + uint64(cnt)*rStep
sStart = uint32(tmpTotal >> vStepLog)
sEnd = uint32(end >> vStepLog)
weight = sEnd - sStart
)
if weight < 1 {
return errors.New("weight < 1")
}
s.norm[i] = int16(weight)
tmpTotal = end
}
}
return nil
}
// validateNorm validates the normalized histogram table.
func (s *Scratch) validateNorm() (err error) {
var total int
for _, v := range s.norm[:s.symbolLen] {
if v >= 0 {
total += int(v)
} else {
total -= int(v)
}
}
defer func() {
if err == nil {
return
}
fmt.Printf("selected TableLog: %d, Symbol length: %d\n", s.actualTableLog, s.symbolLen)
for i, v := range s.norm[:s.symbolLen] {
fmt.Printf("%3d: %5d -> %4d \n", i, s.count[i], v)
}
}()
if total != (1 << s.actualTableLog) {
return fmt.Errorf("warning: Total == %d != %d", total, 1<<s.actualTableLog)
}
for i, v := range s.count[s.symbolLen:] {
if v != 0 {
return fmt.Errorf("warning: Found symbol out of range, %d after cut", i)
}
}
return nil
}
Server/vendor/github.com/klauspost/compress/fse/decompress.go
Generated Vendored
+376
View File
@@ -0,0 +1,376 @@
package fse
import (
"errors"
"fmt"
)
const (
tablelogAbsoluteMax = 15
)
// Decompress a block of data.
// You can provide a scratch buffer to avoid allocations.
// If nil is provided a temporary one will be allocated.
// It is possible, but by no way guaranteed that corrupt data will
// return an error.
// It is up to the caller to verify integrity of the returned data.
// Use a predefined Scratch to set maximum acceptable output size.
func Decompress(b []byte, s *Scratch) ([]byte, error) {
s, err := s.prepare(b)
if err != nil {
return nil, err
}
s.Out = s.Out[:0]
err = s.readNCount()
if err != nil {
return nil, err
}
err = s.buildDtable()
if err != nil {
return nil, err
}
err = s.decompress()
if err != nil {
return nil, err
}
return s.Out, nil
}
// readNCount will read the symbol distribution so decoding tables can be constructed.
func (s *Scratch) readNCount() error {
var (
charnum uint16
previous0 bool
b = &s.br
)
iend := b.remain()
if iend < 4 {
return errors.New("input too small")
}
bitStream := b.Uint32()
nbBits := uint((bitStream & 0xF) + minTablelog) // extract tableLog
if nbBits > tablelogAbsoluteMax {
return errors.New("tableLog too large")
}
bitStream >>= 4
bitCount := uint(4)
s.actualTableLog = uint8(nbBits)
remaining := int32((1 << nbBits) + 1)
threshold := int32(1 << nbBits)
gotTotal := int32(0)
nbBits++
for remaining > 1 {
if previous0 {
n0 := charnum
for (bitStream & 0xFFFF) == 0xFFFF {
n0 += 24
if b.off < iend-5 {
b.advance(2)
bitStream = b.Uint32() >> bitCount
} else {
bitStream >>= 16
bitCount += 16
}
}
for (bitStream & 3) == 3 {
n0 += 3
bitStream >>= 2
bitCount += 2
}
n0 += uint16(bitStream & 3)
bitCount += 2
if n0 > maxSymbolValue {
return errors.New("maxSymbolValue too small")
}
for charnum < n0 {
s.norm[charnum&0xff] = 0
charnum++
}
if b.off <= iend-7 || b.off+int(bitCount>>3) <= iend-4 {
b.advance(bitCount >> 3)
bitCount &= 7
bitStream = b.Uint32() >> bitCount
} else {
bitStream >>= 2
}
}
max := (2*(threshold) - 1) - (remaining)
var count int32
if (int32(bitStream) & (threshold - 1)) < max {
count = int32(bitStream) & (threshold - 1)
bitCount += nbBits - 1
} else {
count = int32(bitStream) & (2*threshold - 1)
if count >= threshold {
count -= max
}
bitCount += nbBits
}
count-- // extra accuracy
if count < 0 {
// -1 means +1
remaining += count
gotTotal -= count
} else {
remaining -= count
gotTotal += count
}
s.norm[charnum&0xff] = int16(count)
charnum++
previous0 = count == 0
for remaining < threshold {
nbBits--
threshold >>= 1
}
if b.off <= iend-7 || b.off+int(bitCount>>3) <= iend-4 {
b.advance(bitCount >> 3)
bitCount &= 7
} else {
bitCount -= (uint)(8 * (len(b.b) - 4 - b.off))
b.off = len(b.b) - 4
}
bitStream = b.Uint32() >> (bitCount & 31)
}
s.symbolLen = charnum
if s.symbolLen <= 1 {
return fmt.Errorf("symbolLen (%d) too small", s.symbolLen)
}
if s.symbolLen > maxSymbolValue+1 {
return fmt.Errorf("symbolLen (%d) too big", s.symbolLen)
}
if remaining != 1 {
return fmt.Errorf("corruption detected (remaining %d != 1)", remaining)
}
if bitCount > 32 {
return fmt.Errorf("corruption detected (bitCount %d > 32)", bitCount)
}
if gotTotal != 1<<s.actualTableLog {
return fmt.Errorf("corruption detected (total %d != %d)", gotTotal, 1<<s.actualTableLog)
}
b.advance((bitCount + 7) >> 3)
return nil
}
// decSymbol contains information about a state entry,
// Including the state offset base, the output symbol and
// the number of bits to read for the low part of the destination state.
type decSymbol struct {
newState uint16
symbol uint8
nbBits uint8
}
// allocDtable will allocate decoding tables if they are not big enough.
func (s *Scratch) allocDtable() {
tableSize := 1 << s.actualTableLog
if cap(s.decTable) < tableSize {
s.decTable = make([]decSymbol, tableSize)
}
s.decTable = s.decTable[:tableSize]
if cap(s.ct.tableSymbol) < 256 {
s.ct.tableSymbol = make([]byte, 256)
}
s.ct.tableSymbol = s.ct.tableSymbol[:256]
if cap(s.ct.stateTable) < 256 {
s.ct.stateTable = make([]uint16, 256)
}
s.ct.stateTable = s.ct.stateTable[:256]
}
// buildDtable will build the decoding table.
func (s *Scratch) buildDtable() error {
tableSize := uint32(1 << s.actualTableLog)
highThreshold := tableSize - 1
s.allocDtable()
symbolNext := s.ct.stateTable[:256]
// Init, lay down lowprob symbols
s.zeroBits = false
{
largeLimit := int16(1 << (s.actualTableLog - 1))
for i, v := range s.norm[:s.symbolLen] {
if v == -1 {
s.decTable[highThreshold].symbol = uint8(i)
highThreshold--
symbolNext[i] = 1
} else {
if v >= largeLimit {
s.zeroBits = true
}
symbolNext[i] = uint16(v)
}
}
}
// Spread symbols
{
tableMask := tableSize - 1
step := tableStep(tableSize)
position := uint32(0)
for ss, v := range s.norm[:s.symbolLen] {
for i := 0; i < int(v); i++ {
s.decTable[position].symbol = uint8(ss)
position = (position + step) & tableMask
for position > highThreshold {
// lowprob area
position = (position + step) & tableMask
}
}
}
if position != 0 {
// position must reach all cells once, otherwise normalizedCounter is incorrect
return errors.New("corrupted input (position != 0)")
}
}
// Build Decoding table
{
tableSize := uint16(1 << s.actualTableLog)
for u, v := range s.decTable {
symbol := v.symbol
nextState := symbolNext[symbol]
symbolNext[symbol] = nextState + 1
nBits := s.actualTableLog - byte(highBits(uint32(nextState)))
s.decTable[u].nbBits = nBits
newState := (nextState << nBits) - tableSize
if newState >= tableSize {
return fmt.Errorf("newState (%d) outside table size (%d)", newState, tableSize)
}
if newState == uint16(u) && nBits == 0 {
// Seems weird that this is possible with nbits > 0.
return fmt.Errorf("newState (%d) == oldState (%d) and no bits", newState, u)
}
s.decTable[u].newState = newState
}
}
return nil
}
// decompress will decompress the bitstream.
// If the buffer is over-read an error is returned.
func (s *Scratch) decompress() error {
br := &s.bits
if err := br.init(s.br.unread()); err != nil {
return err
}
var s1, s2 decoder
// Initialize and decode first state and symbol.
s1.init(br, s.decTable, s.actualTableLog)
s2.init(br, s.decTable, s.actualTableLog)
// Use temp table to avoid bound checks/append penalty.
var tmp = s.ct.tableSymbol[:256]
var off uint8
// Main part
if !s.zeroBits {
for br.off >= 8 {
br.fillFast()
tmp[off+0] = s1.nextFast()
tmp[off+1] = s2.nextFast()
br.fillFast()
tmp[off+2] = s1.nextFast()
tmp[off+3] = s2.nextFast()
off += 4
// When off is 0, we have overflowed and should write.
if off == 0 {
s.Out = append(s.Out, tmp...)
if len(s.Out) >= s.DecompressLimit {
return fmt.Errorf("output size (%d) > DecompressLimit (%d)", len(s.Out), s.DecompressLimit)
}
}
}
} else {
for br.off >= 8 {
br.fillFast()
tmp[off+0] = s1.next()
tmp[off+1] = s2.next()
br.fillFast()
tmp[off+2] = s1.next()
tmp[off+3] = s2.next()
off += 4
if off == 0 {
s.Out = append(s.Out, tmp...)
// When off is 0, we have overflowed and should write.
if len(s.Out) >= s.DecompressLimit {
return fmt.Errorf("output size (%d) > DecompressLimit (%d)", len(s.Out), s.DecompressLimit)
}
}
}
}
s.Out = append(s.Out, tmp[:off]...)
// Final bits, a bit more expensive check
for {
if s1.finished() {
s.Out = append(s.Out, s1.final(), s2.final())
break
}
br.fill()
s.Out = append(s.Out, s1.next())
if s2.finished() {
s.Out = append(s.Out, s2.final(), s1.final())
break
}
s.Out = append(s.Out, s2.next())
if len(s.Out) >= s.DecompressLimit {
return fmt.Errorf("output size (%d) > DecompressLimit (%d)", len(s.Out), s.DecompressLimit)
}
}
return br.close()
}
// decoder keeps track of the current state and updates it from the bitstream.
type decoder struct {
state uint16
br *bitReader
dt []decSymbol
}
// init will initialize the decoder and read the first state from the stream.
func (d *decoder) init(in *bitReader, dt []decSymbol, tableLog uint8) {
d.dt = dt
d.br = in
d.state = in.getBits(tableLog)
}
// next returns the next symbol and sets the next state.
// At least tablelog bits must be available in the bit reader.
func (d *decoder) next() uint8 {
n := &d.dt[d.state]
lowBits := d.br.getBits(n.nbBits)
d.state = n.newState + lowBits
return n.symbol
}
// finished returns true if all bits have been read from the bitstream
// and the next state would require reading bits from the input.
func (d *decoder) finished() bool {
return d.br.finished() && d.dt[d.state].nbBits > 0
}
// final returns the current state symbol without decoding the next.
func (d *decoder) final() uint8 {
return d.dt[d.state].symbol
}
// nextFast returns the next symbol and sets the next state.
// This can only be used if no symbols are 0 bits.
// At least tablelog bits must be available in the bit reader.
func (d *decoder) nextFast() uint8 {
n := d.dt[d.state]
lowBits := d.br.getBitsFast(n.nbBits)
d.state = n.newState + lowBits
return n.symbol
}
Server/vendor/github.com/klauspost/compress/fse/fse.go
Generated Vendored
+144
View File
@@ -0,0 +1,144 @@
// Copyright 2018 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
// Package fse provides Finite State Entropy encoding and decoding.
//
// Finite State Entropy encoding provides a fast near-optimal symbol encoding/decoding
// for byte blocks as implemented in zstd.
//
// See https://github.com/klauspost/compress/tree/master/fse for more information.
package fse
import (
"errors"
"fmt"
"math/bits"
)
const (
/*!MEMORY_USAGE :
* Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
* Increasing memory usage improves compression ratio
* Reduced memory usage can improve speed, due to cache effect
* Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
maxMemoryUsage = 14
defaultMemoryUsage = 13
maxTableLog = maxMemoryUsage - 2
maxTablesize = 1 << maxTableLog
defaultTablelog = defaultMemoryUsage - 2
minTablelog = 5
maxSymbolValue = 255
)
var (
// ErrIncompressible is returned when input is judged to be too hard to compress.
ErrIncompressible = errors.New("input is not compressible")
// ErrUseRLE is returned from the compressor when the input is a single byte value repeated.
ErrUseRLE = errors.New("input is single value repeated")
)
// Scratch provides temporary storage for compression and decompression.
type Scratch struct {
// Private
count [maxSymbolValue + 1]uint32
norm [maxSymbolValue + 1]int16
br byteReader
bits bitReader
bw bitWriter
ct cTable // Compression tables.
decTable []decSymbol // Decompression table.
maxCount int // count of the most probable symbol
// Per block parameters.
// These can be used to override compression parameters of the block.
// Do not touch, unless you know what you are doing.
// Out is output buffer.
// If the scratch is re-used before the caller is done processing the output,
// set this field to nil.
// Otherwise the output buffer will be re-used for next Compression/Decompression step
// and allocation will be avoided.
Out []byte
// DecompressLimit limits the maximum decoded size acceptable.
// If > 0 decompression will stop when approximately this many bytes
// has been decoded.
// If 0, maximum size will be 2GB.
DecompressLimit int
symbolLen uint16 // Length of active part of the symbol table.
actualTableLog uint8 // Selected tablelog.
zeroBits bool // no bits has prob > 50%.
clearCount bool // clear count
// MaxSymbolValue will override the maximum symbol value of the next block.
MaxSymbolValue uint8
// TableLog will attempt to override the tablelog for the next block.
TableLog uint8
}
// Histogram allows to populate the histogram and skip that step in the compression,
// It otherwise allows to inspect the histogram when compression is done.
// To indicate that you have populated the histogram call HistogramFinished
// with the value of the highest populated symbol, as well as the number of entries
// in the most populated entry. These are accepted at face value.
// The returned slice will always be length 256.
func (s *Scratch) Histogram() []uint32 {
return s.count[:]
}
// HistogramFinished can be called to indicate that the histogram has been populated.
// maxSymbol is the index of the highest set symbol of the next data segment.
// maxCount is the number of entries in the most populated entry.
// These are accepted at face value.
func (s *Scratch) HistogramFinished(maxSymbol uint8, maxCount int) {
s.maxCount = maxCount
s.symbolLen = uint16(maxSymbol) + 1
s.clearCount = maxCount != 0
}
// prepare will prepare and allocate scratch tables used for both compression and decompression.
func (s *Scratch) prepare(in []byte) (*Scratch, error) {
if s == nil {
s = &Scratch{}
}
if s.MaxSymbolValue == 0 {
s.MaxSymbolValue = 255
}
if s.TableLog == 0 {
s.TableLog = defaultTablelog
}
if s.TableLog > maxTableLog {
return nil, fmt.Errorf("tableLog (%d) > maxTableLog (%d)", s.TableLog, maxTableLog)
}
if cap(s.Out) == 0 {
s.Out = make([]byte, 0, len(in))
}
if s.clearCount && s.maxCount == 0 {
for i := range s.count {
s.count[i] = 0
}
s.clearCount = false
}
s.br.init(in)
if s.DecompressLimit == 0 {
// Max size 2GB.
s.DecompressLimit = (2 << 30) - 1
}
return s, nil
}
// tableStep returns the next table index.
func tableStep(tableSize uint32) uint32 {
return (tableSize >> 1) + (tableSize >> 3) + 3
}
func highBits(val uint32) (n uint32) {
return uint32(bits.Len32(val) - 1)
}
Server/vendor/github.com/klauspost/compress/gen.sh
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#!/bin/sh
cd s2/cmd/_s2sx/ || exit 1
go generate .
Server/vendor/github.com/klauspost/compress/gzip/gunzip.go
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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package gzip implements reading and writing of gzip format compressed files,
// as specified in RFC 1952.
package gzip
import (
"bufio"
"compress/gzip"
"encoding/binary"
"hash/crc32"
"io"
"time"
"github.com/klauspost/compress/flate"
)
const (
gzipID1 = 0x1f
gzipID2 = 0x8b
gzipDeflate = 8
flagText = 1 << 0
flagHdrCrc = 1 << 1
flagExtra = 1 << 2
flagName = 1 << 3
flagComment = 1 << 4
)
var (
// ErrChecksum is returned when reading GZIP data that has an invalid checksum.
ErrChecksum = gzip.ErrChecksum
// ErrHeader is returned when reading GZIP data that has an invalid header.
ErrHeader = gzip.ErrHeader
)
var le = binary.LittleEndian
// noEOF converts io.EOF to io.ErrUnexpectedEOF.
func noEOF(err error) error {
if err == io.EOF {
return io.ErrUnexpectedEOF
}
return err
}
// The gzip file stores a header giving metadata about the compressed file.
// That header is exposed as the fields of the Writer and Reader structs.
//
// Strings must be UTF-8 encoded and may only contain Unicode code points
// U+0001 through U+00FF, due to limitations of the GZIP file format.
type Header struct {
Comment string // comment
Extra []byte // "extra data"
ModTime time.Time // modification time
Name string // file name
OS byte // operating system type
}
// A Reader is an io.Reader that can be read to retrieve
// uncompressed data from a gzip-format compressed file.
//
// In general, a gzip file can be a concatenation of gzip files,
// each with its own header. Reads from the Reader
// return the concatenation of the uncompressed data of each.
// Only the first header is recorded in the Reader fields.
//
// Gzip files store a length and checksum of the uncompressed data.
// The Reader will return a ErrChecksum when Read
// reaches the end of the uncompressed data if it does not
// have the expected length or checksum. Clients should treat data
// returned by Read as tentative until they receive the io.EOF
// marking the end of the data.
type Reader struct {
Header // valid after NewReader or Reader.Reset
r flate.Reader
br *bufio.Reader
decompressor io.ReadCloser
digest uint32 // CRC-32, IEEE polynomial (section 8)
size uint32 // Uncompressed size (section 2.3.1)
buf [512]byte
err error
multistream bool
}
// NewReader creates a new Reader reading the given reader.
// If r does not also implement io.ByteReader,
// the decompressor may read more data than necessary from r.
//
// It is the caller's responsibility to call Close on the Reader when done.
//
// The Reader.Header fields will be valid in the Reader returned.
func NewReader(r io.Reader) (*Reader, error) {
z := new(Reader)
if err := z.Reset(r); err != nil {
return nil, err
}
return z, nil
}
// Reset discards the Reader z's state and makes it equivalent to the
// result of its original state from NewReader, but reading from r instead.
// This permits reusing a Reader rather than allocating a new one.
func (z *Reader) Reset(r io.Reader) error {
*z = Reader{
decompressor: z.decompressor,
multistream: true,
br: z.br,
}
if rr, ok := r.(flate.Reader); ok {
z.r = rr
} else {
// Reuse if we can.
if z.br != nil {
z.br.Reset(r)
} else {
z.br = bufio.NewReader(r)
}
z.r = z.br
}
z.Header, z.err = z.readHeader()
return z.err
}
// Multistream controls whether the reader supports multistream files.
//
// If enabled (the default), the Reader expects the input to be a sequence
// of individually gzipped data streams, each with its own header and
// trailer, ending at EOF. The effect is that the concatenation of a sequence
// of gzipped files is treated as equivalent to the gzip of the concatenation
// of the sequence. This is standard behavior for gzip readers.
//
// Calling Multistream(false) disables this behavior; disabling the behavior
// can be useful when reading file formats that distinguish individual gzip
// data streams or mix gzip data streams with other data streams.
// In this mode, when the Reader reaches the end of the data stream,
// Read returns io.EOF. If the underlying reader implements io.ByteReader,
// it will be left positioned just after the gzip stream.
// To start the next stream, call z.Reset(r) followed by z.Multistream(false).
// If there is no next stream, z.Reset(r) will return io.EOF.
func (z *Reader) Multistream(ok bool) {
z.multistream = ok
}
// readString reads a NUL-terminated string from z.r.
// It treats the bytes read as being encoded as ISO 8859-1 (Latin-1) and
// will output a string encoded using UTF-8.
// This method always updates z.digest with the data read.
func (z *Reader) readString() (string, error) {
var err error
needConv := false
for i := 0; ; i++ {
if i >= len(z.buf) {
return "", ErrHeader
}
z.buf[i], err = z.r.ReadByte()
if err != nil {
return "", err
}
if z.buf[i] > 0x7f {
needConv = true
}
if z.buf[i] == 0 {
// Digest covers the NUL terminator.
z.digest = crc32.Update(z.digest, crc32.IEEETable, z.buf[:i+1])
// Strings are ISO 8859-1, Latin-1 (RFC 1952, section 2.3.1).
if needConv {
s := make([]rune, 0, i)
for _, v := range z.buf[:i] {
s = append(s, rune(v))
}
return string(s), nil
}
return string(z.buf[:i]), nil
}
}
}
// readHeader reads the GZIP header according to section 2.3.1.
// This method does not set z.err.
func (z *Reader) readHeader() (hdr Header, err error) {
if _, err = io.ReadFull(z.r, z.buf[:10]); err != nil {
// RFC 1952, section 2.2, says the following:
// A gzip file consists of a series of "members" (compressed data sets).
//
// Other than this, the specification does not clarify whether a
// "series" is defined as "one or more" or "zero or more". To err on the
// side of caution, Go interprets this to mean "zero or more".
// Thus, it is okay to return io.EOF here.
return hdr, err
}
if z.buf[0] != gzipID1 || z.buf[1] != gzipID2 || z.buf[2] != gzipDeflate {
return hdr, ErrHeader
}
flg := z.buf[3]
hdr.ModTime = time.Unix(int64(le.Uint32(z.buf[4:8])), 0)
// z.buf[8] is XFL and is currently ignored.
hdr.OS = z.buf[9]
z.digest = crc32.ChecksumIEEE(z.buf[:10])
if flg&flagExtra != 0 {
if _, err = io.ReadFull(z.r, z.buf[:2]); err != nil {
return hdr, noEOF(err)
}
z.digest = crc32.Update(z.digest, crc32.IEEETable, z.buf[:2])
data := make([]byte, le.Uint16(z.buf[:2]))
if _, err = io.ReadFull(z.r, data); err != nil {
return hdr, noEOF(err)
}
z.digest = crc32.Update(z.digest, crc32.IEEETable, data)
hdr.Extra = data
}
var s string
if flg&flagName != 0 {
if s, err = z.readString(); err != nil {
return hdr, err
}
hdr.Name = s
}
if flg&flagComment != 0 {
if s, err = z.readString(); err != nil {
return hdr, err
}
hdr.Comment = s
}
if flg&flagHdrCrc != 0 {
if _, err = io.ReadFull(z.r, z.buf[:2]); err != nil {
return hdr, noEOF(err)
}
digest := le.Uint16(z.buf[:2])
if digest != uint16(z.digest) {
return hdr, ErrHeader
}
}
// Reserved FLG bits must be zero.
if flg>>5 != 0 {
return hdr, ErrHeader
}
z.digest = 0
if z.decompressor == nil {
z.decompressor = flate.NewReader(z.r)
} else {
z.decompressor.(flate.Resetter).Reset(z.r, nil)
}
return hdr, nil
}
// Read implements io.Reader, reading uncompressed bytes from its underlying Reader.
func (z *Reader) Read(p []byte) (n int, err error) {
if z.err != nil {
return 0, z.err
}
for n == 0 {
n, z.err = z.decompressor.Read(p)
z.digest = crc32.Update(z.digest, crc32.IEEETable, p[:n])
z.size += uint32(n)
if z.err != io.EOF {
// In the normal case we return here.
return n, z.err
}
// Finished file; check checksum and size.
if _, err := io.ReadFull(z.r, z.buf[:8]); err != nil {
z.err = noEOF(err)
return n, z.err
}
digest := le.Uint32(z.buf[:4])
size := le.Uint32(z.buf[4:8])
if digest != z.digest || size != z.size {
z.err = ErrChecksum
return n, z.err
}
z.digest, z.size = 0, 0
// File is ok; check if there is another.
if !z.multistream {
return n, io.EOF
}
z.err = nil // Remove io.EOF
if _, z.err = z.readHeader(); z.err != nil {
return n, z.err
}
}
return n, nil
}
type crcer interface {
io.Writer
Sum32() uint32
Reset()
}
type crcUpdater struct {
z *Reader
}
func (c *crcUpdater) Write(p []byte) (int, error) {
c.z.digest = crc32.Update(c.z.digest, crc32.IEEETable, p)
return len(p), nil
}
func (c *crcUpdater) Sum32() uint32 {
return c.z.digest
}
func (c *crcUpdater) Reset() {
c.z.digest = 0
}
// WriteTo support the io.WriteTo interface for io.Copy and friends.
func (z *Reader) WriteTo(w io.Writer) (int64, error) {
total := int64(0)
crcWriter := crcer(crc32.NewIEEE())
if z.digest != 0 {
crcWriter = &crcUpdater{z: z}
}
for {
if z.err != nil {
if z.err == io.EOF {
return total, nil
}
return total, z.err
}
// We write both to output and digest.
mw := io.MultiWriter(w, crcWriter)
n, err := z.decompressor.(io.WriterTo).WriteTo(mw)
total += n
z.size += uint32(n)
if err != nil {
z.err = err
return total, z.err
}
// Finished file; check checksum + size.
if _, err := io.ReadFull(z.r, z.buf[0:8]); err != nil {
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
z.err = err
return total, err
}
z.digest = crcWriter.Sum32()
digest := le.Uint32(z.buf[:4])
size := le.Uint32(z.buf[4:8])
if digest != z.digest || size != z.size {
z.err = ErrChecksum
return total, z.err
}
z.digest, z.size = 0, 0
// File is ok; check if there is another.
if !z.multistream {
return total, nil
}
crcWriter.Reset()
z.err = nil // Remove io.EOF
if _, z.err = z.readHeader(); z.err != nil {
if z.err == io.EOF {
return total, nil
}
return total, z.err
}
}
}
// Close closes the Reader. It does not close the underlying io.Reader.
// In order for the GZIP checksum to be verified, the reader must be
// fully consumed until the io.EOF.
func (z *Reader) Close() error { return z.decompressor.Close() }
Server/vendor/github.com/klauspost/compress/gzip/gzip.go
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// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package gzip
import (
"errors"
"fmt"
"hash/crc32"
"io"
"github.com/klauspost/compress/flate"
)
// These constants are copied from the flate package, so that code that imports
// "compress/gzip" does not also have to import "compress/flate".
const (
NoCompression = flate.NoCompression
BestSpeed = flate.BestSpeed
BestCompression = flate.BestCompression
DefaultCompression = flate.DefaultCompression
ConstantCompression = flate.ConstantCompression
HuffmanOnly = flate.HuffmanOnly
// StatelessCompression will do compression but without maintaining any state
// between Write calls.
// There will be no memory kept between Write calls,
// but compression and speed will be suboptimal.
// Because of this, the size of actual Write calls will affect output size.
StatelessCompression = -3
)
// A Writer is an io.WriteCloser.
// Writes to a Writer are compressed and written to w.
type Writer struct {
Header // written at first call to Write, Flush, or Close
w io.Writer
level int
err error
compressor *flate.Writer
digest uint32 // CRC-32, IEEE polynomial (section 8)
size uint32 // Uncompressed size (section 2.3.1)
wroteHeader bool
closed bool
buf [10]byte
}
// NewWriter returns a new Writer.
// Writes to the returned writer are compressed and written to w.
//
// It is the caller's responsibility to call Close on the WriteCloser when done.
// Writes may be buffered and not flushed until Close.
//
// Callers that wish to set the fields in Writer.Header must do so before
// the first call to Write, Flush, or Close.
func NewWriter(w io.Writer) *Writer {
z, _ := NewWriterLevel(w, DefaultCompression)
return z
}
// NewWriterLevel is like NewWriter but specifies the compression level instead
// of assuming DefaultCompression.
//
// The compression level can be DefaultCompression, NoCompression, or any
// integer value between BestSpeed and BestCompression inclusive. The error
// returned will be nil if the level is valid.
func NewWriterLevel(w io.Writer, level int) (*Writer, error) {
if level < StatelessCompression || level > BestCompression {
return nil, fmt.Errorf("gzip: invalid compression level: %d", level)
}
z := new(Writer)
z.init(w, level)
return z, nil
}
// MinCustomWindowSize is the minimum window size that can be sent to NewWriterWindow.
const MinCustomWindowSize = flate.MinCustomWindowSize
// MaxCustomWindowSize is the maximum custom window that can be sent to NewWriterWindow.
const MaxCustomWindowSize = flate.MaxCustomWindowSize
// NewWriterWindow returns a new Writer compressing data with a custom window size.
// windowSize must be from MinCustomWindowSize to MaxCustomWindowSize.
func NewWriterWindow(w io.Writer, windowSize int) (*Writer, error) {
if windowSize < MinCustomWindowSize {
return nil, errors.New("gzip: requested window size less than MinWindowSize")
}
if windowSize > MaxCustomWindowSize {
return nil, errors.New("gzip: requested window size bigger than MaxCustomWindowSize")
}
z := new(Writer)
z.init(w, -windowSize)
return z, nil
}
func (z *Writer) init(w io.Writer, level int) {
compressor := z.compressor
if level != StatelessCompression {
if compressor != nil {
compressor.Reset(w)
}
}
*z = Writer{
Header: Header{
OS: 255, // unknown
},
w: w,
level: level,
compressor: compressor,
}
}
// Reset discards the Writer z's state and makes it equivalent to the
// result of its original state from NewWriter or NewWriterLevel, but
// writing to w instead. This permits reusing a Writer rather than
// allocating a new one.
func (z *Writer) Reset(w io.Writer) {
z.init(w, z.level)
}
// writeBytes writes a length-prefixed byte slice to z.w.
func (z *Writer) writeBytes(b []byte) error {
if len(b) > 0xffff {
return errors.New("gzip.Write: Extra data is too large")
}
le.PutUint16(z.buf[:2], uint16(len(b)))
_, err := z.w.Write(z.buf[:2])
if err != nil {
return err
}
_, err = z.w.Write(b)
return err
}
// writeString writes a UTF-8 string s in GZIP's format to z.w.
// GZIP (RFC 1952) specifies that strings are NUL-terminated ISO 8859-1 (Latin-1).
func (z *Writer) writeString(s string) (err error) {
// GZIP stores Latin-1 strings; error if non-Latin-1; convert if non-ASCII.
needconv := false
for _, v := range s {
if v == 0 || v > 0xff {
return errors.New("gzip.Write: non-Latin-1 header string")
}
if v > 0x7f {
needconv = true
}
}
if needconv {
b := make([]byte, 0, len(s))
for _, v := range s {
b = append(b, byte(v))
}
_, err = z.w.Write(b)
} else {
_, err = io.WriteString(z.w, s)
}
if err != nil {
return err
}
// GZIP strings are NUL-terminated.
z.buf[0] = 0
_, err = z.w.Write(z.buf[:1])
return err
}
// Write writes a compressed form of p to the underlying io.Writer. The
// compressed bytes are not necessarily flushed until the Writer is closed.
func (z *Writer) Write(p []byte) (int, error) {
if z.err != nil {
return 0, z.err
}
var n int
// Write the GZIP header lazily.
if !z.wroteHeader {
z.wroteHeader = true
z.buf[0] = gzipID1
z.buf[1] = gzipID2
z.buf[2] = gzipDeflate
z.buf[3] = 0
if z.Extra != nil {
z.buf[3] |= 0x04
}
if z.Name != "" {
z.buf[3] |= 0x08
}
if z.Comment != "" {
z.buf[3] |= 0x10
}
le.PutUint32(z.buf[4:8], uint32(z.ModTime.Unix()))
if z.level == BestCompression {
z.buf[8] = 2
} else if z.level == BestSpeed {
z.buf[8] = 4
} else {
z.buf[8] = 0
}
z.buf[9] = z.OS
n, z.err = z.w.Write(z.buf[:10])
if z.err != nil {
return n, z.err
}
if z.Extra != nil {
z.err = z.writeBytes(z.Extra)
if z.err != nil {
return n, z.err
}
}
if z.Name != "" {
z.err = z.writeString(z.Name)
if z.err != nil {
return n, z.err
}
}
if z.Comment != "" {
z.err = z.writeString(z.Comment)
if z.err != nil {
return n, z.err
}
}
if z.compressor == nil && z.level != StatelessCompression {
z.compressor, _ = flate.NewWriter(z.w, z.level)
}
}
z.size += uint32(len(p))
z.digest = crc32.Update(z.digest, crc32.IEEETable, p)
if z.level == StatelessCompression {
return len(p), flate.StatelessDeflate(z.w, p, false, nil)
}
n, z.err = z.compressor.Write(p)
return n, z.err
}
// Flush flushes any pending compressed data to the underlying writer.
//
// It is useful mainly in compressed network protocols, to ensure that
// a remote reader has enough data to reconstruct a packet. Flush does
// not return until the data has been written. If the underlying
// writer returns an error, Flush returns that error.
//
// In the terminology of the zlib library, Flush is equivalent to Z_SYNC_FLUSH.
func (z *Writer) Flush() error {
if z.err != nil {
return z.err
}
if z.closed || z.level == StatelessCompression {
return nil
}
if !z.wroteHeader {
z.Write(nil)
if z.err != nil {
return z.err
}
}
z.err = z.compressor.Flush()
return z.err
}
// Close closes the Writer, flushing any unwritten data to the underlying
// io.Writer, but does not close the underlying io.Writer.
func (z *Writer) Close() error {
if z.err != nil {
return z.err
}
if z.closed {
return nil
}
z.closed = true
if !z.wroteHeader {
z.Write(nil)
if z.err != nil {
return z.err
}
}
if z.level == StatelessCompression {
z.err = flate.StatelessDeflate(z.w, nil, true, nil)
} else {
z.err = z.compressor.Close()
}
if z.err != nil {
return z.err
}
le.PutUint32(z.buf[:4], z.digest)
le.PutUint32(z.buf[4:8], z.size)
_, z.err = z.w.Write(z.buf[:8])
return z.err
}
Server/vendor/github.com/klauspost/compress/huff0/.gitignore
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/huff0-fuzz.zip
Server/vendor/github.com/klauspost/compress/huff0/README.md
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# Huff0 entropy compression
This package provides Huff0 encoding and decoding as used in zstd.
[Huff0](https://github.com/Cyan4973/FiniteStateEntropy#new-generation-entropy-coders),
a Huffman codec designed for modern CPU, featuring OoO (Out of Order) operations on multiple ALU
(Arithmetic Logic Unit), achieving extremely fast compression and decompression speeds.
This can be used for compressing input with a lot of similar input values to the smallest number of bytes.
This does not perform any multi-byte [dictionary coding](https://en.wikipedia.org/wiki/Dictionary_coder) as LZ coders,
but it can be used as a secondary step to compressors (like Snappy) that does not do entropy encoding.
* [Godoc documentation](https://godoc.org/github.com/klauspost/compress/huff0)
## News
This is used as part of the [zstandard](https://github.com/klauspost/compress/tree/master/zstd#zstd) compression and decompression package.
This ensures that most functionality is well tested.
# Usage
This package provides a low level interface that allows to compress single independent blocks.
Each block is separate, and there is no built in integrity checks.
This means that the caller should keep track of block sizes and also do checksums if needed.
Compressing a block is done via the [`Compress1X`](https://godoc.org/github.com/klauspost/compress/huff0#Compress1X) and
[`Compress4X`](https://godoc.org/github.com/klauspost/compress/huff0#Compress4X) functions.
You must provide input and will receive the output and maybe an error.
These error values can be returned:
| Error | Description |
|---------------------|-----------------------------------------------------------------------------|
| `<nil>` | Everything ok, output is returned |
| `ErrIncompressible` | Returned when input is judged to be too hard to compress |
| `ErrUseRLE` | Returned from the compressor when the input is a single byte value repeated |
| `ErrTooBig` | Returned if the input block exceeds the maximum allowed size (128 Kib) |
| `(error)` | An internal error occurred. |
As can be seen above some of there are errors that will be returned even under normal operation so it is important to handle these.
To reduce allocations you can provide a [`Scratch`](https://godoc.org/github.com/klauspost/compress/huff0#Scratch) object
that can be re-used for successive calls. Both compression and decompression accepts a `Scratch` object, and the same
object can be used for both.
Be aware, that when re-using a `Scratch` object that the *output* buffer is also re-used, so if you are still using this
you must set the `Out` field in the scratch to nil. The same buffer is used for compression and decompression output.
The `Scratch` object will retain state that allows to re-use previous tables for encoding and decoding.
## Tables and re-use
Huff0 allows for reusing tables from the previous block to save space if that is expected to give better/faster results.
The Scratch object allows you to set a [`ReusePolicy`](https://godoc.org/github.com/klauspost/compress/huff0#ReusePolicy)
that controls this behaviour. See the documentation for details. This can be altered between each block.
Do however note that this information is *not* stored in the output block and it is up to the users of the package to
record whether [`ReadTable`](https://godoc.org/github.com/klauspost/compress/huff0#ReadTable) should be called,
based on the boolean reported back from the CompressXX call.
If you want to store the table separate from the data, you can access them as `OutData` and `OutTable` on the
[`Scratch`](https://godoc.org/github.com/klauspost/compress/huff0#Scratch) object.
## Decompressing
The first part of decoding is to initialize the decoding table through [`ReadTable`](https://godoc.org/github.com/klauspost/compress/huff0#ReadTable).
This will initialize the decoding tables.
You can supply the complete block to `ReadTable` and it will return the data part of the block
which can be given to the decompressor.
Decompressing is done by calling the [`Decompress1X`](https://godoc.org/github.com/klauspost/compress/huff0#Scratch.Decompress1X)
or [`Decompress4X`](https://godoc.org/github.com/klauspost/compress/huff0#Scratch.Decompress4X) function.
For concurrently decompressing content with a fixed table a stateless [`Decoder`](https://godoc.org/github.com/klauspost/compress/huff0#Decoder) can be requested which will remain correct as long as the scratch is unchanged. The capacity of the provided slice indicates the expected output size.
You must provide the output from the compression stage, at exactly the size you got back. If you receive an error back
your input was likely corrupted.
It is important to note that a successful decoding does *not* mean your output matches your original input.
There are no integrity checks, so relying on errors from the decompressor does not assure your data is valid.
# Contributing
Contributions are always welcome. Be aware that adding public functions will require good justification and breaking
changes will likely not be accepted. If in doubt open an issue before writing the PR.
Server/vendor/github.com/klauspost/compress/huff0/bitreader.go
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// Copyright 2018 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
package huff0
import (
"errors"
"fmt"
"io"
"github.com/klauspost/compress/internal/le"
)
// bitReader reads a bitstream in reverse.
// The last set bit indicates the start of the stream and is used
// for aligning the input.
type bitReaderBytes struct {
in []byte
off uint // next byte to read is at in[off - 1]
value uint64
bitsRead uint8
}
// init initializes and resets the bit reader.
func (b *bitReaderBytes) init(in []byte) error {
if len(in) < 1 {
return errors.New("corrupt stream: too short")
}
b.in = in
b.off = uint(len(in))
// The highest bit of the last byte indicates where to start
v := in[len(in)-1]
if v == 0 {
return errors.New("corrupt stream, did not find end of stream")
}
b.bitsRead = 64
b.value = 0
if len(in) >= 8 {
b.fillFastStart()
} else {
b.fill()
b.fill()
}
b.advance(8 - uint8(highBit32(uint32(v))))
return nil
}
// peekByteFast requires that at least one byte is requested every time.
// There are no checks if the buffer is filled.
func (b *bitReaderBytes) peekByteFast() uint8 {
got := uint8(b.value >> 56)
return got
}
func (b *bitReaderBytes) advance(n uint8) {
b.bitsRead += n
b.value <<= n & 63
}
// fillFast() will make sure at least 32 bits are available.
// There must be at least 4 bytes available.
func (b *bitReaderBytes) fillFast() {
if b.bitsRead < 32 {
return
}
// 2 bounds checks.
low := le.Load32(b.in, b.off-4)
b.value |= uint64(low) << (b.bitsRead - 32)
b.bitsRead -= 32
b.off -= 4
}
// fillFastStart() assumes the bitReaderBytes is empty and there is at least 8 bytes to read.
func (b *bitReaderBytes) fillFastStart() {
// Do single re-slice to avoid bounds checks.
b.value = le.Load64(b.in, b.off-8)
b.bitsRead = 0
b.off -= 8
}
// fill() will make sure at least 32 bits are available.
func (b *bitReaderBytes) fill() {
if b.bitsRead < 32 {
return
}
if b.off >= 4 {
low := le.Load32(b.in, b.off-4)
b.value |= uint64(low) << (b.bitsRead - 32)
b.bitsRead -= 32
b.off -= 4
return
}
for b.off > 0 {
b.value |= uint64(b.in[b.off-1]) << (b.bitsRead - 8)
b.bitsRead -= 8
b.off--
}
}
// finished returns true if all bits have been read from the bit stream.
func (b *bitReaderBytes) finished() bool {
return b.off == 0 && b.bitsRead >= 64
}
func (b *bitReaderBytes) remaining() uint {
return b.off*8 + uint(64-b.bitsRead)
}
// close the bitstream and returns an error if out-of-buffer reads occurred.
func (b *bitReaderBytes) close() error {
// Release reference.
b.in = nil
if b.remaining() > 0 {
return fmt.Errorf("corrupt input: %d bits remain on stream", b.remaining())
}
if b.bitsRead > 64 {
return io.ErrUnexpectedEOF
}
return nil
}
// bitReaderShifted reads a bitstream in reverse.
// The last set bit indicates the start of the stream and is used
// for aligning the input.
type bitReaderShifted struct {
in []byte
off uint // next byte to read is at in[off - 1]
value uint64
bitsRead uint8
}
// init initializes and resets the bit reader.
func (b *bitReaderShifted) init(in []byte) error {
if len(in) < 1 {
return errors.New("corrupt stream: too short")
}
b.in = in
b.off = uint(len(in))
// The highest bit of the last byte indicates where to start
v := in[len(in)-1]
if v == 0 {
return errors.New("corrupt stream, did not find end of stream")
}
b.bitsRead = 64
b.value = 0
if len(in) >= 8 {
b.fillFastStart()
} else {
b.fill()
b.fill()
}
b.advance(8 - uint8(highBit32(uint32(v))))
return nil
}
// peekBitsFast requires that at least one bit is requested every time.
// There are no checks if the buffer is filled.
func (b *bitReaderShifted) peekBitsFast(n uint8) uint16 {
return uint16(b.value >> ((64 - n) & 63))
}
func (b *bitReaderShifted) advance(n uint8) {
b.bitsRead += n
b.value <<= n & 63
}
// fillFast() will make sure at least 32 bits are available.
// There must be at least 4 bytes available.
func (b *bitReaderShifted) fillFast() {
if b.bitsRead < 32 {
return
}
low := le.Load32(b.in, b.off-4)
b.value |= uint64(low) << ((b.bitsRead - 32) & 63)
b.bitsRead -= 32
b.off -= 4
}
// fillFastStart() assumes the bitReaderShifted is empty and there is at least 8 bytes to read.
func (b *bitReaderShifted) fillFastStart() {
b.value = le.Load64(b.in, b.off-8)
b.bitsRead = 0
b.off -= 8
}
// fill() will make sure at least 32 bits are available.
func (b *bitReaderShifted) fill() {
if b.bitsRead < 32 {
return
}
if b.off > 4 {
low := le.Load32(b.in, b.off-4)
b.value |= uint64(low) << ((b.bitsRead - 32) & 63)
b.bitsRead -= 32
b.off -= 4
return
}
for b.off > 0 {
b.value |= uint64(b.in[b.off-1]) << ((b.bitsRead - 8) & 63)
b.bitsRead -= 8
b.off--
}
}
func (b *bitReaderShifted) remaining() uint {
return b.off*8 + uint(64-b.bitsRead)
}
// close the bitstream and returns an error if out-of-buffer reads occurred.
func (b *bitReaderShifted) close() error {
// Release reference.
b.in = nil
if b.remaining() > 0 {
return fmt.Errorf("corrupt input: %d bits remain on stream", b.remaining())
}
if b.bitsRead > 64 {
return io.ErrUnexpectedEOF
}
return nil
}
Server/vendor/github.com/klauspost/compress/huff0/bitwriter.go
Generated Vendored
+102
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// Copyright 2018 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
package huff0
// bitWriter will write bits.
// First bit will be LSB of the first byte of output.
type bitWriter struct {
bitContainer uint64
nBits uint8
out []byte
}
// addBits16Clean will add up to 16 bits. value may not contain more set bits than indicated.
// It will not check if there is space for them, so the caller must ensure that it has flushed recently.
func (b *bitWriter) addBits16Clean(value uint16, bits uint8) {
b.bitContainer |= uint64(value) << (b.nBits & 63)
b.nBits += bits
}
// encSymbol will add up to 16 bits. value may not contain more set bits than indicated.
// It will not check if there is space for them, so the caller must ensure that it has flushed recently.
func (b *bitWriter) encSymbol(ct cTable, symbol byte) {
enc := ct[symbol]
b.bitContainer |= uint64(enc.val) << (b.nBits & 63)
if false {
if enc.nBits == 0 {
panic("nbits 0")
}
}
b.nBits += enc.nBits
}
// encTwoSymbols will add up to 32 bits. value may not contain more set bits than indicated.
// It will not check if there is space for them, so the caller must ensure that it has flushed recently.
func (b *bitWriter) encTwoSymbols(ct cTable, av, bv byte) {
encA := ct[av]
encB := ct[bv]
sh := b.nBits & 63
combined := uint64(encA.val) | (uint64(encB.val) << (encA.nBits & 63))
b.bitContainer |= combined << sh
if false {
if encA.nBits == 0 {
panic("nbitsA 0")
}
if encB.nBits == 0 {
panic("nbitsB 0")
}
}
b.nBits += encA.nBits + encB.nBits
}
// encFourSymbols adds up to 32 bits from four symbols.
// It will not check if there is space for them,
// so the caller must ensure that b has been flushed recently.
func (b *bitWriter) encFourSymbols(encA, encB, encC, encD cTableEntry) {
bitsA := encA.nBits
bitsB := bitsA + encB.nBits
bitsC := bitsB + encC.nBits
bitsD := bitsC + encD.nBits
combined := uint64(encA.val) |
(uint64(encB.val) << (bitsA & 63)) |
(uint64(encC.val) << (bitsB & 63)) |
(uint64(encD.val) << (bitsC & 63))
b.bitContainer |= combined << (b.nBits & 63)
b.nBits += bitsD
}
// flush32 will flush out, so there are at least 32 bits available for writing.
func (b *bitWriter) flush32() {
if b.nBits < 32 {
return
}
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
byte(b.bitContainer>>24))
b.nBits -= 32
b.bitContainer >>= 32
}
// flushAlign will flush remaining full bytes and align to next byte boundary.
func (b *bitWriter) flushAlign() {
nbBytes := (b.nBits + 7) >> 3
for i := range nbBytes {
b.out = append(b.out, byte(b.bitContainer>>(i*8)))
}
b.nBits = 0
b.bitContainer = 0
}
// close will write the alignment bit and write the final byte(s)
// to the output.
func (b *bitWriter) close() {
// End mark
b.addBits16Clean(1, 1)
// flush until next byte.
b.flushAlign()
}
Server/vendor/github.com/klauspost/compress/huff0/compress.go
Generated Vendored
+742
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package huff0
import (
"fmt"
"math"
"runtime"
"sync"
)
// Compress1X will compress the input.
// The output can be decoded using Decompress1X.
// Supply a Scratch object. The scratch object contains state about re-use,
// So when sharing across independent encodes, be sure to set the re-use policy.
func Compress1X(in []byte, s *Scratch) (out []byte, reUsed bool, err error) {
s, err = s.prepare(in)
if err != nil {
return nil, false, err
}
return compress(in, s, s.compress1X)
}
// Compress4X will compress the input. The input is split into 4 independent blocks
// and compressed similar to Compress1X.
// The output can be decoded using Decompress4X.
// Supply a Scratch object. The scratch object contains state about re-use,
// So when sharing across independent encodes, be sure to set the re-use policy.
func Compress4X(in []byte, s *Scratch) (out []byte, reUsed bool, err error) {
s, err = s.prepare(in)
if err != nil {
return nil, false, err
}
if false {
// TODO: compress4Xp only slightly faster.
const parallelThreshold = 8 << 10
if len(in) < parallelThreshold || runtime.GOMAXPROCS(0) == 1 {
return compress(in, s, s.compress4X)
}
return compress(in, s, s.compress4Xp)
}
return compress(in, s, s.compress4X)
}
func compress(in []byte, s *Scratch, compressor func(src []byte) ([]byte, error)) (out []byte, reUsed bool, err error) {
// Nuke previous table if we cannot reuse anyway.
if s.Reuse == ReusePolicyNone {
s.prevTable = s.prevTable[:0]
}
// Create histogram, if none was provided.
maxCount := s.maxCount
var canReuse = false
if maxCount == 0 {
maxCount, canReuse = s.countSimple(in)
} else {
canReuse = s.canUseTable(s.prevTable)
}
// We want the output size to be less than this:
wantSize := len(in)
if s.WantLogLess > 0 {
wantSize -= wantSize >> s.WantLogLess
}
// Reset for next run.
s.clearCount = true
s.maxCount = 0
if maxCount >= len(in) {
if maxCount > len(in) {
return nil, false, fmt.Errorf("maxCount (%d) > length (%d)", maxCount, len(in))
}
if len(in) == 1 {
return nil, false, ErrIncompressible
}
// One symbol, use RLE
return nil, false, ErrUseRLE
}
if maxCount == 1 || maxCount < (len(in)>>7) {
// Each symbol present maximum once or too well distributed.
return nil, false, ErrIncompressible
}
if s.Reuse == ReusePolicyMust && !canReuse {
// We must reuse, but we can't.
return nil, false, ErrIncompressible
}
if (s.Reuse == ReusePolicyPrefer || s.Reuse == ReusePolicyMust) && canReuse {
keepTable := s.cTable
keepTL := s.actualTableLog
s.cTable = s.prevTable
s.actualTableLog = s.prevTableLog
s.Out, err = compressor(in)
s.cTable = keepTable
s.actualTableLog = keepTL
if err == nil && len(s.Out) < wantSize {
s.OutData = s.Out
return s.Out, true, nil
}
if s.Reuse == ReusePolicyMust {
return nil, false, ErrIncompressible
}
// Do not attempt to re-use later.
s.prevTable = s.prevTable[:0]
}
// Calculate new table.
err = s.buildCTable()
if err != nil {
return nil, false, err
}
if false && !s.canUseTable(s.cTable) {
panic("invalid table generated")
}
if s.Reuse == ReusePolicyAllow && canReuse {
hSize := len(s.Out)
oldSize := s.prevTable.estimateSize(s.count[:s.symbolLen])
newSize := s.cTable.estimateSize(s.count[:s.symbolLen])
if oldSize <= hSize+newSize || hSize+12 >= wantSize {
// Retain cTable even if we re-use.
keepTable := s.cTable
keepTL := s.actualTableLog
s.cTable = s.prevTable
s.actualTableLog = s.prevTableLog
s.Out, err = compressor(in)
// Restore ctable.
s.cTable = keepTable
s.actualTableLog = keepTL
if err != nil {
return nil, false, err
}
if len(s.Out) >= wantSize {
return nil, false, ErrIncompressible
}
s.OutData = s.Out
return s.Out, true, nil
}
}
// Use new table
err = s.cTable.write(s)
if err != nil {
s.OutTable = nil
return nil, false, err
}
s.OutTable = s.Out
// Compress using new table
s.Out, err = compressor(in)
if err != nil {
s.OutTable = nil
return nil, false, err
}
if len(s.Out) >= wantSize {
s.OutTable = nil
return nil, false, ErrIncompressible
}
// Move current table into previous.
s.prevTable, s.prevTableLog, s.cTable = s.cTable, s.actualTableLog, s.prevTable[:0]
s.OutData = s.Out[len(s.OutTable):]
return s.Out, false, nil
}
// EstimateSizes will estimate the data sizes
func EstimateSizes(in []byte, s *Scratch) (tableSz, dataSz, reuseSz int, err error) {
s, err = s.prepare(in)
if err != nil {
return 0, 0, 0, err
}
// Create histogram, if none was provided.
tableSz, dataSz, reuseSz = -1, -1, -1
maxCount := s.maxCount
var canReuse = false
if maxCount == 0 {
maxCount, canReuse = s.countSimple(in)
} else {
canReuse = s.canUseTable(s.prevTable)
}
// We want the output size to be less than this:
wantSize := len(in)
if s.WantLogLess > 0 {
wantSize -= wantSize >> s.WantLogLess
}
// Reset for next run.
s.clearCount = true
s.maxCount = 0
if maxCount >= len(in) {
if maxCount > len(in) {
return 0, 0, 0, fmt.Errorf("maxCount (%d) > length (%d)", maxCount, len(in))
}
if len(in) == 1 {
return 0, 0, 0, ErrIncompressible
}
// One symbol, use RLE
return 0, 0, 0, ErrUseRLE
}
if maxCount == 1 || maxCount < (len(in)>>7) {
// Each symbol present maximum once or too well distributed.
return 0, 0, 0, ErrIncompressible
}
// Calculate new table.
err = s.buildCTable()
if err != nil {
return 0, 0, 0, err
}
if false && !s.canUseTable(s.cTable) {
panic("invalid table generated")
}
tableSz, err = s.cTable.estTableSize(s)
if err != nil {
return 0, 0, 0, err
}
if canReuse {
reuseSz = s.prevTable.estimateSize(s.count[:s.symbolLen])
}
dataSz = s.cTable.estimateSize(s.count[:s.symbolLen])
// Restore
return tableSz, dataSz, reuseSz, nil
}
func (s *Scratch) compress1X(src []byte) ([]byte, error) {
return s.compress1xDo(s.Out, src), nil
}
func (s *Scratch) compress1xDo(dst, src []byte) []byte {
var bw = bitWriter{out: dst}
// N is length divisible by 4.
n := len(src)
n -= n & 3
cTable := s.cTable[:256]
// Encode last bytes.
for i := len(src) & 3; i > 0; i-- {
bw.encSymbol(cTable, src[n+i-1])
}
n -= 4
if s.actualTableLog <= 8 {
for ; n >= 0; n -= 4 {
tmp := src[n : n+4]
// tmp should be len 4
bw.flush32()
bw.encFourSymbols(cTable[tmp[3]], cTable[tmp[2]], cTable[tmp[1]], cTable[tmp[0]])
}
} else {
for ; n >= 0; n -= 4 {
tmp := src[n : n+4]
// tmp should be len 4
bw.flush32()
bw.encTwoSymbols(cTable, tmp[3], tmp[2])
bw.flush32()
bw.encTwoSymbols(cTable, tmp[1], tmp[0])
}
}
bw.close()
return bw.out
}
var sixZeros [6]byte
func (s *Scratch) compress4X(src []byte) ([]byte, error) {
if len(src) < 12 {
return nil, ErrIncompressible
}
segmentSize := (len(src) + 3) / 4
// Add placeholder for output length
offsetIdx := len(s.Out)
s.Out = append(s.Out, sixZeros[:]...)
for i := range 4 {
toDo := src
if len(toDo) > segmentSize {
toDo = toDo[:segmentSize]
}
src = src[len(toDo):]
idx := len(s.Out)
s.Out = s.compress1xDo(s.Out, toDo)
if len(s.Out)-idx > math.MaxUint16 {
// We cannot store the size in the jump table
return nil, ErrIncompressible
}
// Write compressed length as little endian before block.
if i < 3 {
// Last length is not written.
length := len(s.Out) - idx
s.Out[i*2+offsetIdx] = byte(length)
s.Out[i*2+offsetIdx+1] = byte(length >> 8)
}
}
return s.Out, nil
}
// compress4Xp will compress 4 streams using separate goroutines.
func (s *Scratch) compress4Xp(src []byte) ([]byte, error) {
if len(src) < 12 {
return nil, ErrIncompressible
}
// Add placeholder for output length
s.Out = s.Out[:6]
segmentSize := (len(src) + 3) / 4
var wg sync.WaitGroup
wg.Add(4)
for i := range 4 {
toDo := src
if len(toDo) > segmentSize {
toDo = toDo[:segmentSize]
}
src = src[len(toDo):]
// Separate goroutine for each block.
go func(i int) {
s.tmpOut[i] = s.compress1xDo(s.tmpOut[i][:0], toDo)
wg.Done()
}(i)
}
wg.Wait()
for i := range 4 {
o := s.tmpOut[i]
if len(o) > math.MaxUint16 {
// We cannot store the size in the jump table
return nil, ErrIncompressible
}
// Write compressed length as little endian before block.
if i < 3 {
// Last length is not written.
s.Out[i*2] = byte(len(o))
s.Out[i*2+1] = byte(len(o) >> 8)
}
// Write output.
s.Out = append(s.Out, o...)
}
return s.Out, nil
}
// countSimple will create a simple histogram in s.count.
// Returns the biggest count.
// Does not update s.clearCount.
func (s *Scratch) countSimple(in []byte) (max int, reuse bool) {
reuse = true
_ = s.count // Assert that s != nil to speed up the following loop.
for _, v := range in {
s.count[v]++
}
m := uint32(0)
if len(s.prevTable) > 0 {
for i, v := range s.count[:] {
if v == 0 {
continue
}
if v > m {
m = v
}
s.symbolLen = uint16(i) + 1
if i >= len(s.prevTable) {
reuse = false
} else if s.prevTable[i].nBits == 0 {
reuse = false
}
}
return int(m), reuse
}
for i, v := range s.count[:] {
if v == 0 {
continue
}
if v > m {
m = v
}
s.symbolLen = uint16(i) + 1
}
return int(m), false
}
func (s *Scratch) canUseTable(c cTable) bool {
if len(c) < int(s.symbolLen) {
return false
}
for i, v := range s.count[:s.symbolLen] {
if v != 0 && c[i].nBits == 0 {
return false
}
}
return true
}
//lint:ignore U1000 used for debugging
func (s *Scratch) validateTable(c cTable) bool {
if len(c) < int(s.symbolLen) {
return false
}
for i, v := range s.count[:s.symbolLen] {
if v != 0 {
if c[i].nBits == 0 {
return false
}
if c[i].nBits > s.actualTableLog {
return false
}
}
}
return true
}
// minTableLog provides the minimum logSize to safely represent a distribution.
func (s *Scratch) minTableLog() uint8 {
minBitsSrc := highBit32(uint32(s.srcLen)) + 1
minBitsSymbols := highBit32(uint32(s.symbolLen-1)) + 2
if minBitsSrc < minBitsSymbols {
return uint8(minBitsSrc)
}
return uint8(minBitsSymbols)
}
// optimalTableLog calculates and sets the optimal tableLog in s.actualTableLog
func (s *Scratch) optimalTableLog() {
tableLog := s.TableLog
minBits := s.minTableLog()
maxBitsSrc := uint8(highBit32(uint32(s.srcLen-1))) - 1
if maxBitsSrc < tableLog {
// Accuracy can be reduced
tableLog = maxBitsSrc
}
if minBits > tableLog {
tableLog = minBits
}
// Need a minimum to safely represent all symbol values
if tableLog < minTablelog {
tableLog = minTablelog
}
if tableLog > tableLogMax {
tableLog = tableLogMax
}
s.actualTableLog = tableLog
}
type cTableEntry struct {
val uint16
nBits uint8
// We have 8 bits extra
}
const huffNodesMask = huffNodesLen - 1
func (s *Scratch) buildCTable() error {
s.optimalTableLog()
s.huffSort()
if cap(s.cTable) < maxSymbolValue+1 {
s.cTable = make([]cTableEntry, s.symbolLen, maxSymbolValue+1)
} else {
s.cTable = s.cTable[:s.symbolLen]
for i := range s.cTable {
s.cTable[i] = cTableEntry{}
}
}
var startNode = int16(s.symbolLen)
nonNullRank := s.symbolLen - 1
nodeNb := startNode
huffNode := s.nodes[1 : huffNodesLen+1]
// This overlays the slice above, but allows "-1" index lookups.
// Different from reference implementation.
huffNode0 := s.nodes[0 : huffNodesLen+1]
for huffNode[nonNullRank].count() == 0 {
nonNullRank--
}
lowS := int16(nonNullRank)
nodeRoot := nodeNb + lowS - 1
lowN := nodeNb
huffNode[nodeNb].setCount(huffNode[lowS].count() + huffNode[lowS-1].count())
huffNode[lowS].setParent(nodeNb)
huffNode[lowS-1].setParent(nodeNb)
nodeNb++
lowS -= 2
for n := nodeNb; n <= nodeRoot; n++ {
huffNode[n].setCount(1 << 30)
}
// fake entry, strong barrier
huffNode0[0].setCount(1 << 31)
// create parents
for nodeNb <= nodeRoot {
var n1, n2 int16
if huffNode0[lowS+1].count() < huffNode0[lowN+1].count() {
n1 = lowS
lowS--
} else {
n1 = lowN
lowN++
}
if huffNode0[lowS+1].count() < huffNode0[lowN+1].count() {
n2 = lowS
lowS--
} else {
n2 = lowN
lowN++
}
huffNode[nodeNb].setCount(huffNode0[n1+1].count() + huffNode0[n2+1].count())
huffNode0[n1+1].setParent(nodeNb)
huffNode0[n2+1].setParent(nodeNb)
nodeNb++
}
// distribute weights (unlimited tree height)
huffNode[nodeRoot].setNbBits(0)
for n := nodeRoot - 1; n >= startNode; n-- {
huffNode[n].setNbBits(huffNode[huffNode[n].parent()].nbBits() + 1)
}
for n := uint16(0); n <= nonNullRank; n++ {
huffNode[n].setNbBits(huffNode[huffNode[n].parent()].nbBits() + 1)
}
s.actualTableLog = s.setMaxHeight(int(nonNullRank))
maxNbBits := s.actualTableLog
// fill result into tree (val, nbBits)
if maxNbBits > tableLogMax {
return fmt.Errorf("internal error: maxNbBits (%d) > tableLogMax (%d)", maxNbBits, tableLogMax)
}
var nbPerRank [tableLogMax + 1]uint16
var valPerRank [16]uint16
for _, v := range huffNode[:nonNullRank+1] {
nbPerRank[v.nbBits()]++
}
// determine stating value per rank
{
min := uint16(0)
for n := maxNbBits; n > 0; n-- {
// get starting value within each rank
valPerRank[n] = min
min += nbPerRank[n]
min >>= 1
}
}
// push nbBits per symbol, symbol order
for _, v := range huffNode[:nonNullRank+1] {
s.cTable[v.symbol()].nBits = v.nbBits()
}
// assign value within rank, symbol order
t := s.cTable[:s.symbolLen]
for n, val := range t {
nbits := val.nBits & 15
v := valPerRank[nbits]
t[n].val = v
valPerRank[nbits] = v + 1
}
return nil
}
// huffSort will sort symbols, decreasing order.
func (s *Scratch) huffSort() {
type rankPos struct {
base uint32
current uint32
}
// Clear nodes
nodes := s.nodes[:huffNodesLen+1]
s.nodes = nodes
nodes = nodes[1 : huffNodesLen+1]
// Sort into buckets based on length of symbol count.
var rank [32]rankPos
for _, v := range s.count[:s.symbolLen] {
r := highBit32(v+1) & 31
rank[r].base++
}
// maxBitLength is log2(BlockSizeMax) + 1
const maxBitLength = 18 + 1
for n := maxBitLength; n > 0; n-- {
rank[n-1].base += rank[n].base
}
for n := range rank[:maxBitLength] {
rank[n].current = rank[n].base
}
for n, c := range s.count[:s.symbolLen] {
r := (highBit32(c+1) + 1) & 31
pos := rank[r].current
rank[r].current++
prev := nodes[(pos-1)&huffNodesMask]
for pos > rank[r].base && c > prev.count() {
nodes[pos&huffNodesMask] = prev
pos--
prev = nodes[(pos-1)&huffNodesMask]
}
nodes[pos&huffNodesMask] = makeNodeElt(c, byte(n))
}
}
func (s *Scratch) setMaxHeight(lastNonNull int) uint8 {
maxNbBits := s.actualTableLog
huffNode := s.nodes[1 : huffNodesLen+1]
//huffNode = huffNode[: huffNodesLen]
largestBits := huffNode[lastNonNull].nbBits()
// early exit : no elt > maxNbBits
if largestBits <= maxNbBits {
return largestBits
}
totalCost := int(0)
baseCost := int(1) << (largestBits - maxNbBits)
n := uint32(lastNonNull)
for huffNode[n].nbBits() > maxNbBits {
totalCost += baseCost - (1 << (largestBits - huffNode[n].nbBits()))
huffNode[n].setNbBits(maxNbBits)
n--
}
// n stops at huffNode[n].nbBits <= maxNbBits
for huffNode[n].nbBits() == maxNbBits {
n--
}
// n end at index of smallest symbol using < maxNbBits
// renorm totalCost
totalCost >>= largestBits - maxNbBits /* note : totalCost is necessarily a multiple of baseCost */
// repay normalized cost
{
const noSymbol = 0xF0F0F0F0
var rankLast [tableLogMax + 2]uint32
for i := range rankLast[:] {
rankLast[i] = noSymbol
}
// Get pos of last (smallest) symbol per rank
{
currentNbBits := maxNbBits
for pos := int(n); pos >= 0; pos-- {
if huffNode[pos].nbBits() >= currentNbBits {
continue
}
currentNbBits = huffNode[pos].nbBits() // < maxNbBits
rankLast[maxNbBits-currentNbBits] = uint32(pos)
}
}
for totalCost > 0 {
nBitsToDecrease := uint8(highBit32(uint32(totalCost))) + 1
for ; nBitsToDecrease > 1; nBitsToDecrease-- {
highPos := rankLast[nBitsToDecrease]
lowPos := rankLast[nBitsToDecrease-1]
if highPos == noSymbol {
continue
}
if lowPos == noSymbol {
break
}
highTotal := huffNode[highPos].count()
lowTotal := 2 * huffNode[lowPos].count()
if highTotal <= lowTotal {
break
}
}
// only triggered when no more rank 1 symbol left => find closest one (note : there is necessarily at least one !)
// HUF_MAX_TABLELOG test just to please gcc 5+; but it should not be necessary
// FIXME: try to remove
for (nBitsToDecrease <= tableLogMax) && (rankLast[nBitsToDecrease] == noSymbol) {
nBitsToDecrease++
}
totalCost -= 1 << (nBitsToDecrease - 1)
if rankLast[nBitsToDecrease-1] == noSymbol {
// this rank is no longer empty
rankLast[nBitsToDecrease-1] = rankLast[nBitsToDecrease]
}
huffNode[rankLast[nBitsToDecrease]].setNbBits(1 +
huffNode[rankLast[nBitsToDecrease]].nbBits())
if rankLast[nBitsToDecrease] == 0 {
/* special case, reached largest symbol */
rankLast[nBitsToDecrease] = noSymbol
} else {
rankLast[nBitsToDecrease]--
if huffNode[rankLast[nBitsToDecrease]].nbBits() != maxNbBits-nBitsToDecrease {
rankLast[nBitsToDecrease] = noSymbol /* this rank is now empty */
}
}
}
for totalCost < 0 { /* Sometimes, cost correction overshoot */
if rankLast[1] == noSymbol { /* special case : no rank 1 symbol (using maxNbBits-1); let's create one from largest rank 0 (using maxNbBits) */
for huffNode[n].nbBits() == maxNbBits {
n--
}
huffNode[n+1].setNbBits(huffNode[n+1].nbBits() - 1)
rankLast[1] = n + 1
totalCost++
continue
}
huffNode[rankLast[1]+1].setNbBits(huffNode[rankLast[1]+1].nbBits() - 1)
rankLast[1]++
totalCost++
}
}
return maxNbBits
}
// A nodeElt is the fields
//
// count uint32
// parent uint16
// symbol byte
// nbBits uint8
//
// in some order, all squashed into an integer so that the compiler
// always loads and stores entire nodeElts instead of separate fields.
type nodeElt uint64
func makeNodeElt(count uint32, symbol byte) nodeElt {
return nodeElt(count) | nodeElt(symbol)<<48
}
func (e *nodeElt) count() uint32 { return uint32(*e) }
func (e *nodeElt) parent() uint16 { return uint16(*e >> 32) }
func (e *nodeElt) symbol() byte { return byte(*e >> 48) }
func (e *nodeElt) nbBits() uint8 { return uint8(*e >> 56) }
func (e *nodeElt) setCount(c uint32) { *e = (*e)&0xffffffff00000000 | nodeElt(c) }
func (e *nodeElt) setParent(p int16) { *e = (*e)&0xffff0000ffffffff | nodeElt(uint16(p))<<32 }
func (e *nodeElt) setNbBits(n uint8) { *e = (*e)&0x00ffffffffffffff | nodeElt(n)<<56 }
Server/vendor/github.com/klauspost/compress/huff0/decompress.go
Generated Vendored
+1161
View File
File diff suppressed because it is too large Load Diff
Server/vendor/github.com/klauspost/compress/huff0/decompress_amd64.go
Generated Vendored
+222
View File
@@ -0,0 +1,222 @@
//go:build amd64 && !appengine && !noasm && gc
// This file contains the specialisation of Decoder.Decompress4X
// and Decoder.Decompress1X that use an asm implementation of thir main loops.
package huff0
import (
"errors"
"fmt"
"github.com/klauspost/compress/internal/cpuinfo"
)
// decompress4x_main_loop_x86 is an x86 assembler implementation
// of Decompress4X when tablelog > 8.
//
//go:noescape
func decompress4x_main_loop_amd64(ctx *decompress4xContext)
// decompress4x_8b_loop_x86 is an x86 assembler implementation
// of Decompress4X when tablelog <= 8 which decodes 4 entries
// per loop.
//
//go:noescape
func decompress4x_8b_main_loop_amd64(ctx *decompress4xContext)
// fallback8BitSize is the size where using Go version is faster.
const fallback8BitSize = 800
type decompress4xContext struct {
pbr *[4]bitReaderShifted
peekBits uint8
out *byte
dstEvery int
tbl *dEntrySingle
decoded int
limit *byte
}
// Decompress4X will decompress a 4X encoded stream.
// The length of the supplied input must match the end of a block exactly.
// The *capacity* of the dst slice must match the destination size of
// the uncompressed data exactly.
func (d *Decoder) Decompress4X(dst, src []byte) ([]byte, error) {
if len(d.dt.single) == 0 {
return nil, errors.New("no table loaded")
}
if len(src) < 6+(4*1) {
return nil, errors.New("input too small")
}
use8BitTables := d.actualTableLog <= 8
if cap(dst) < fallback8BitSize && use8BitTables {
return d.decompress4X8bit(dst, src)
}
var br [4]bitReaderShifted
// Decode "jump table"
start := 6
for i := range 3 {
length := int(src[i*2]) | (int(src[i*2+1]) << 8)
if start+length >= len(src) {
return nil, errors.New("truncated input (or invalid offset)")
}
err := br[i].init(src[start : start+length])
if err != nil {
return nil, err
}
start += length
}
err := br[3].init(src[start:])
if err != nil {
return nil, err
}
// destination, offset to match first output
dstSize := cap(dst)
dst = dst[:dstSize]
out := dst
dstEvery := (dstSize + 3) / 4
const tlSize = 1 << tableLogMax
const tlMask = tlSize - 1
single := d.dt.single[:tlSize]
var decoded int
if len(out) > 4*4 && !(br[0].off < 4 || br[1].off < 4 || br[2].off < 4 || br[3].off < 4) {
ctx := decompress4xContext{
pbr: &br,
peekBits: uint8((64 - d.actualTableLog) & 63), // see: bitReaderShifted.peekBitsFast()
out: &out[0],
dstEvery: dstEvery,
tbl: &single[0],
limit: &out[dstEvery-4], // Always stop decoding when first buffer gets here to avoid writing OOB on last.
}
if use8BitTables {
decompress4x_8b_main_loop_amd64(&ctx)
} else {
decompress4x_main_loop_amd64(&ctx)
}
decoded = ctx.decoded
out = out[decoded/4:]
}
// Decode remaining.
remainBytes := dstEvery - (decoded / 4)
for i := range br {
offset := dstEvery * i
endsAt := min(offset+remainBytes, len(out))
br := &br[i]
bitsLeft := br.remaining()
for bitsLeft > 0 {
br.fill()
if offset >= endsAt {
return nil, errors.New("corruption detected: stream overrun 4")
}
// Read value and increment offset.
val := br.peekBitsFast(d.actualTableLog)
v := single[val&tlMask].entry
nBits := uint8(v)
br.advance(nBits)
bitsLeft -= uint(nBits)
out[offset] = uint8(v >> 8)
offset++
}
if offset != endsAt {
return nil, fmt.Errorf("corruption detected: short output block %d, end %d != %d", i, offset, endsAt)
}
decoded += offset - dstEvery*i
err = br.close()
if err != nil {
return nil, err
}
}
if dstSize != decoded {
return nil, errors.New("corruption detected: short output block")
}
return dst, nil
}
// decompress4x_main_loop_x86 is an x86 assembler implementation
// of Decompress1X when tablelog > 8.
//
//go:noescape
func decompress1x_main_loop_amd64(ctx *decompress1xContext)
// decompress4x_main_loop_x86 is an x86 with BMI2 assembler implementation
// of Decompress1X when tablelog > 8.
//
//go:noescape
func decompress1x_main_loop_bmi2(ctx *decompress1xContext)
type decompress1xContext struct {
pbr *bitReaderShifted
peekBits uint8
out *byte
outCap int
tbl *dEntrySingle
decoded int
}
// Error reported by asm implementations
const error_max_decoded_size_exeeded = -1
// Decompress1X will decompress a 1X encoded stream.
// The cap of the output buffer will be the maximum decompressed size.
// The length of the supplied input must match the end of a block exactly.
func (d *Decoder) Decompress1X(dst, src []byte) ([]byte, error) {
if len(d.dt.single) == 0 {
return nil, errors.New("no table loaded")
}
var br bitReaderShifted
err := br.init(src)
if err != nil {
return dst, err
}
maxDecodedSize := cap(dst)
dst = dst[:maxDecodedSize]
const tlSize = 1 << tableLogMax
const tlMask = tlSize - 1
if maxDecodedSize >= 4 {
ctx := decompress1xContext{
pbr: &br,
out: &dst[0],
outCap: maxDecodedSize,
peekBits: uint8((64 - d.actualTableLog) & 63), // see: bitReaderShifted.peekBitsFast()
tbl: &d.dt.single[0],
}
if cpuinfo.HasBMI2() {
decompress1x_main_loop_bmi2(&ctx)
} else {
decompress1x_main_loop_amd64(&ctx)
}
if ctx.decoded == error_max_decoded_size_exeeded {
return nil, ErrMaxDecodedSizeExceeded
}
dst = dst[:ctx.decoded]
}
// br < 8, so uint8 is fine
bitsLeft := uint8(br.off)*8 + 64 - br.bitsRead
for bitsLeft > 0 {
br.fill()
if len(dst) >= maxDecodedSize {
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
v := d.dt.single[br.peekBitsFast(d.actualTableLog)&tlMask]
nBits := uint8(v.entry)
br.advance(nBits)
bitsLeft -= nBits
dst = append(dst, uint8(v.entry>>8))
}
return dst, br.close()
}
Server/vendor/github.com/klauspost/compress/huff0/decompress_amd64.s
Generated Vendored
+830
View File
@@ -0,0 +1,830 @@
// Code generated by command: go run gen.go -out ../decompress_amd64.s -pkg=huff0. DO NOT EDIT.
//go:build amd64 && !appengine && !noasm && gc
// func decompress4x_main_loop_amd64(ctx *decompress4xContext)
TEXT ·decompress4x_main_loop_amd64(SB), $0-8
// Preload values
MOVQ ctx+0(FP), AX
MOVBQZX 8(AX), DI
MOVQ 16(AX), BX
MOVQ 48(AX), SI
MOVQ 24(AX), R8
MOVQ 32(AX), R9
MOVQ (AX), R10
// Main loop
main_loop:
XORL DX, DX
CMPQ BX, SI
SETGE DL
// br0.fillFast32()
MOVQ 32(R10), R11
MOVBQZX 40(R10), R12
CMPQ R12, $0x20
JBE skip_fill0
MOVQ 24(R10), AX
SUBQ $0x20, R12
SUBQ $0x04, AX
MOVQ (R10), R13
// b.value |= uint64(low) << (b.bitsRead & 63)
MOVL (AX)(R13*1), R13
MOVQ R12, CX
SHLQ CL, R13
MOVQ AX, 24(R10)
ORQ R13, R11
// exhausted += (br0.off < 4)
CMPQ AX, $0x04
ADCB $+0, DL
skip_fill0:
// val0 := br0.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v0 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br0.advance(uint8(v0.entry)
MOVB CH, AL
SHLQ CL, R11
ADDB CL, R12
// val1 := br0.peekTopBits(peekBits)
MOVQ DI, CX
MOVQ R11, R13
SHRQ CL, R13
// v1 := table[val1&mask]
MOVW (R9)(R13*2), CX
// br0.advance(uint8(v1.entry))
MOVB CH, AH
SHLQ CL, R11
ADDB CL, R12
// these two writes get coalesced
// out[id * dstEvery + 0] = uint8(v0.entry >> 8)
// out[id * dstEvery + 1] = uint8(v1.entry >> 8)
MOVW AX, (BX)
// update the bitreader structure
MOVQ R11, 32(R10)
MOVB R12, 40(R10)
// br1.fillFast32()
MOVQ 80(R10), R11
MOVBQZX 88(R10), R12
CMPQ R12, $0x20
JBE skip_fill1
MOVQ 72(R10), AX
SUBQ $0x20, R12
SUBQ $0x04, AX
MOVQ 48(R10), R13
// b.value |= uint64(low) << (b.bitsRead & 63)
MOVL (AX)(R13*1), R13
MOVQ R12, CX
SHLQ CL, R13
MOVQ AX, 72(R10)
ORQ R13, R11
// exhausted += (br1.off < 4)
CMPQ AX, $0x04
ADCB $+0, DL
skip_fill1:
// val0 := br1.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v0 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br1.advance(uint8(v0.entry)
MOVB CH, AL
SHLQ CL, R11
ADDB CL, R12
// val1 := br1.peekTopBits(peekBits)
MOVQ DI, CX
MOVQ R11, R13
SHRQ CL, R13
// v1 := table[val1&mask]
MOVW (R9)(R13*2), CX
// br1.advance(uint8(v1.entry))
MOVB CH, AH
SHLQ CL, R11
ADDB CL, R12
// these two writes get coalesced
// out[id * dstEvery + 0] = uint8(v0.entry >> 8)
// out[id * dstEvery + 1] = uint8(v1.entry >> 8)
MOVW AX, (BX)(R8*1)
// update the bitreader structure
MOVQ R11, 80(R10)
MOVB R12, 88(R10)
// br2.fillFast32()
MOVQ 128(R10), R11
MOVBQZX 136(R10), R12
CMPQ R12, $0x20
JBE skip_fill2
MOVQ 120(R10), AX
SUBQ $0x20, R12
SUBQ $0x04, AX
MOVQ 96(R10), R13
// b.value |= uint64(low) << (b.bitsRead & 63)
MOVL (AX)(R13*1), R13
MOVQ R12, CX
SHLQ CL, R13
MOVQ AX, 120(R10)
ORQ R13, R11
// exhausted += (br2.off < 4)
CMPQ AX, $0x04
ADCB $+0, DL
skip_fill2:
// val0 := br2.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v0 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br2.advance(uint8(v0.entry)
MOVB CH, AL
SHLQ CL, R11
ADDB CL, R12
// val1 := br2.peekTopBits(peekBits)
MOVQ DI, CX
MOVQ R11, R13
SHRQ CL, R13
// v1 := table[val1&mask]
MOVW (R9)(R13*2), CX
// br2.advance(uint8(v1.entry))
MOVB CH, AH
SHLQ CL, R11
ADDB CL, R12
// these two writes get coalesced
// out[id * dstEvery + 0] = uint8(v0.entry >> 8)
// out[id * dstEvery + 1] = uint8(v1.entry >> 8)
MOVW AX, (BX)(R8*2)
// update the bitreader structure
MOVQ R11, 128(R10)
MOVB R12, 136(R10)
// br3.fillFast32()
MOVQ 176(R10), R11
MOVBQZX 184(R10), R12
CMPQ R12, $0x20
JBE skip_fill3
MOVQ 168(R10), AX
SUBQ $0x20, R12
SUBQ $0x04, AX
MOVQ 144(R10), R13
// b.value |= uint64(low) << (b.bitsRead & 63)
MOVL (AX)(R13*1), R13
MOVQ R12, CX
SHLQ CL, R13
MOVQ AX, 168(R10)
ORQ R13, R11
// exhausted += (br3.off < 4)
CMPQ AX, $0x04
ADCB $+0, DL
skip_fill3:
// val0 := br3.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v0 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br3.advance(uint8(v0.entry)
MOVB CH, AL
SHLQ CL, R11
ADDB CL, R12
// val1 := br3.peekTopBits(peekBits)
MOVQ DI, CX
MOVQ R11, R13
SHRQ CL, R13
// v1 := table[val1&mask]
MOVW (R9)(R13*2), CX
// br3.advance(uint8(v1.entry))
MOVB CH, AH
SHLQ CL, R11
ADDB CL, R12
// these two writes get coalesced
// out[id * dstEvery + 0] = uint8(v0.entry >> 8)
// out[id * dstEvery + 1] = uint8(v1.entry >> 8)
LEAQ (R8)(R8*2), CX
MOVW AX, (BX)(CX*1)
// update the bitreader structure
MOVQ R11, 176(R10)
MOVB R12, 184(R10)
ADDQ $0x02, BX
TESTB DL, DL
JZ main_loop
MOVQ ctx+0(FP), AX
SUBQ 16(AX), BX
SHLQ $0x02, BX
MOVQ BX, 40(AX)
RET
// func decompress4x_8b_main_loop_amd64(ctx *decompress4xContext)
TEXT ·decompress4x_8b_main_loop_amd64(SB), $0-8
// Preload values
MOVQ ctx+0(FP), CX
MOVBQZX 8(CX), DI
MOVQ 16(CX), BX
MOVQ 48(CX), SI
MOVQ 24(CX), R8
MOVQ 32(CX), R9
MOVQ (CX), R10
// Main loop
main_loop:
XORL DX, DX
CMPQ BX, SI
SETGE DL
// br0.fillFast32()
MOVQ 32(R10), R11
MOVBQZX 40(R10), R12
CMPQ R12, $0x20
JBE skip_fill0
MOVQ 24(R10), R13
SUBQ $0x20, R12
SUBQ $0x04, R13
MOVQ (R10), R14
// b.value |= uint64(low) << (b.bitsRead & 63)
MOVL (R13)(R14*1), R14
MOVQ R12, CX
SHLQ CL, R14
MOVQ R13, 24(R10)
ORQ R14, R11
// exhausted += (br0.off < 4)
CMPQ R13, $0x04
ADCB $+0, DL
skip_fill0:
// val0 := br0.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v0 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br0.advance(uint8(v0.entry)
MOVB CH, AL
SHLQ CL, R11
ADDB CL, R12
// val1 := br0.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v1 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br0.advance(uint8(v1.entry)
MOVB CH, AH
SHLQ CL, R11
ADDB CL, R12
BSWAPL AX
// val2 := br0.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v2 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br0.advance(uint8(v2.entry)
MOVB CH, AH
SHLQ CL, R11
ADDB CL, R12
// val3 := br0.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v3 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br0.advance(uint8(v3.entry)
MOVB CH, AL
SHLQ CL, R11
ADDB CL, R12
BSWAPL AX
// these four writes get coalesced
// out[id * dstEvery + 0] = uint8(v0.entry >> 8)
// out[id * dstEvery + 1] = uint8(v1.entry >> 8)
// out[id * dstEvery + 3] = uint8(v2.entry >> 8)
// out[id * dstEvery + 4] = uint8(v3.entry >> 8)
MOVL AX, (BX)
// update the bitreader structure
MOVQ R11, 32(R10)
MOVB R12, 40(R10)
// br1.fillFast32()
MOVQ 80(R10), R11
MOVBQZX 88(R10), R12
CMPQ R12, $0x20
JBE skip_fill1
MOVQ 72(R10), R13
SUBQ $0x20, R12
SUBQ $0x04, R13
MOVQ 48(R10), R14
// b.value |= uint64(low) << (b.bitsRead & 63)
MOVL (R13)(R14*1), R14
MOVQ R12, CX
SHLQ CL, R14
MOVQ R13, 72(R10)
ORQ R14, R11
// exhausted += (br1.off < 4)
CMPQ R13, $0x04
ADCB $+0, DL
skip_fill1:
// val0 := br1.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v0 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br1.advance(uint8(v0.entry)
MOVB CH, AL
SHLQ CL, R11
ADDB CL, R12
// val1 := br1.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v1 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br1.advance(uint8(v1.entry)
MOVB CH, AH
SHLQ CL, R11
ADDB CL, R12
BSWAPL AX
// val2 := br1.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v2 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br1.advance(uint8(v2.entry)
MOVB CH, AH
SHLQ CL, R11
ADDB CL, R12
// val3 := br1.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v3 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br1.advance(uint8(v3.entry)
MOVB CH, AL
SHLQ CL, R11
ADDB CL, R12
BSWAPL AX
// these four writes get coalesced
// out[id * dstEvery + 0] = uint8(v0.entry >> 8)
// out[id * dstEvery + 1] = uint8(v1.entry >> 8)
// out[id * dstEvery + 3] = uint8(v2.entry >> 8)
// out[id * dstEvery + 4] = uint8(v3.entry >> 8)
MOVL AX, (BX)(R8*1)
// update the bitreader structure
MOVQ R11, 80(R10)
MOVB R12, 88(R10)
// br2.fillFast32()
MOVQ 128(R10), R11
MOVBQZX 136(R10), R12
CMPQ R12, $0x20
JBE skip_fill2
MOVQ 120(R10), R13
SUBQ $0x20, R12
SUBQ $0x04, R13
MOVQ 96(R10), R14
// b.value |= uint64(low) << (b.bitsRead & 63)
MOVL (R13)(R14*1), R14
MOVQ R12, CX
SHLQ CL, R14
MOVQ R13, 120(R10)
ORQ R14, R11
// exhausted += (br2.off < 4)
CMPQ R13, $0x04
ADCB $+0, DL
skip_fill2:
// val0 := br2.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v0 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br2.advance(uint8(v0.entry)
MOVB CH, AL
SHLQ CL, R11
ADDB CL, R12
// val1 := br2.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v1 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br2.advance(uint8(v1.entry)
MOVB CH, AH
SHLQ CL, R11
ADDB CL, R12
BSWAPL AX
// val2 := br2.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v2 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br2.advance(uint8(v2.entry)
MOVB CH, AH
SHLQ CL, R11
ADDB CL, R12
// val3 := br2.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v3 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br2.advance(uint8(v3.entry)
MOVB CH, AL
SHLQ CL, R11
ADDB CL, R12
BSWAPL AX
// these four writes get coalesced
// out[id * dstEvery + 0] = uint8(v0.entry >> 8)
// out[id * dstEvery + 1] = uint8(v1.entry >> 8)
// out[id * dstEvery + 3] = uint8(v2.entry >> 8)
// out[id * dstEvery + 4] = uint8(v3.entry >> 8)
MOVL AX, (BX)(R8*2)
// update the bitreader structure
MOVQ R11, 128(R10)
MOVB R12, 136(R10)
// br3.fillFast32()
MOVQ 176(R10), R11
MOVBQZX 184(R10), R12
CMPQ R12, $0x20
JBE skip_fill3
MOVQ 168(R10), R13
SUBQ $0x20, R12
SUBQ $0x04, R13
MOVQ 144(R10), R14
// b.value |= uint64(low) << (b.bitsRead & 63)
MOVL (R13)(R14*1), R14
MOVQ R12, CX
SHLQ CL, R14
MOVQ R13, 168(R10)
ORQ R14, R11
// exhausted += (br3.off < 4)
CMPQ R13, $0x04
ADCB $+0, DL
skip_fill3:
// val0 := br3.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v0 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br3.advance(uint8(v0.entry)
MOVB CH, AL
SHLQ CL, R11
ADDB CL, R12
// val1 := br3.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v1 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br3.advance(uint8(v1.entry)
MOVB CH, AH
SHLQ CL, R11
ADDB CL, R12
BSWAPL AX
// val2 := br3.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v2 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br3.advance(uint8(v2.entry)
MOVB CH, AH
SHLQ CL, R11
ADDB CL, R12
// val3 := br3.peekTopBits(peekBits)
MOVQ R11, R13
MOVQ DI, CX
SHRQ CL, R13
// v3 := table[val0&mask]
MOVW (R9)(R13*2), CX
// br3.advance(uint8(v3.entry)
MOVB CH, AL
SHLQ CL, R11
ADDB CL, R12
BSWAPL AX
// these four writes get coalesced
// out[id * dstEvery + 0] = uint8(v0.entry >> 8)
// out[id * dstEvery + 1] = uint8(v1.entry >> 8)
// out[id * dstEvery + 3] = uint8(v2.entry >> 8)
// out[id * dstEvery + 4] = uint8(v3.entry >> 8)
LEAQ (R8)(R8*2), CX
MOVL AX, (BX)(CX*1)
// update the bitreader structure
MOVQ R11, 176(R10)
MOVB R12, 184(R10)
ADDQ $0x04, BX
TESTB DL, DL
JZ main_loop
MOVQ ctx+0(FP), AX
SUBQ 16(AX), BX
SHLQ $0x02, BX
MOVQ BX, 40(AX)
RET
// func decompress1x_main_loop_amd64(ctx *decompress1xContext)
TEXT ·decompress1x_main_loop_amd64(SB), $0-8
MOVQ ctx+0(FP), CX
MOVQ 16(CX), DX
MOVQ 24(CX), BX
CMPQ BX, $0x04
JB error_max_decoded_size_exceeded
LEAQ (DX)(BX*1), BX
MOVQ (CX), SI
MOVQ (SI), R8
MOVQ 24(SI), R9
MOVQ 32(SI), R10
MOVBQZX 40(SI), R11
MOVQ 32(CX), SI
MOVBQZX 8(CX), DI
JMP loop_condition
main_loop:
// Check if we have room for 4 bytes in the output buffer
LEAQ 4(DX), CX
CMPQ CX, BX
JGE error_max_decoded_size_exceeded
// Decode 4 values
CMPQ R11, $0x20
JL bitReader_fillFast_1_end
SUBQ $0x20, R11
SUBQ $0x04, R9
MOVL (R8)(R9*1), R12
MOVQ R11, CX
SHLQ CL, R12
ORQ R12, R10
bitReader_fillFast_1_end:
MOVQ DI, CX
MOVQ R10, R12
SHRQ CL, R12
MOVW (SI)(R12*2), CX
MOVB CH, AL
MOVBQZX CL, CX
ADDQ CX, R11
SHLQ CL, R10
MOVQ DI, CX
MOVQ R10, R12
SHRQ CL, R12
MOVW (SI)(R12*2), CX
MOVB CH, AH
MOVBQZX CL, CX
ADDQ CX, R11
SHLQ CL, R10
BSWAPL AX
CMPQ R11, $0x20
JL bitReader_fillFast_2_end
SUBQ $0x20, R11
SUBQ $0x04, R9
MOVL (R8)(R9*1), R12
MOVQ R11, CX
SHLQ CL, R12
ORQ R12, R10
bitReader_fillFast_2_end:
MOVQ DI, CX
MOVQ R10, R12
SHRQ CL, R12
MOVW (SI)(R12*2), CX
MOVB CH, AH
MOVBQZX CL, CX
ADDQ CX, R11
SHLQ CL, R10
MOVQ DI, CX
MOVQ R10, R12
SHRQ CL, R12
MOVW (SI)(R12*2), CX
MOVB CH, AL
MOVBQZX CL, CX
ADDQ CX, R11
SHLQ CL, R10
BSWAPL AX
// Store the decoded values
MOVL AX, (DX)
ADDQ $0x04, DX
loop_condition:
CMPQ R9, $0x08
JGE main_loop
// Update ctx structure
MOVQ ctx+0(FP), AX
SUBQ 16(AX), DX
MOVQ DX, 40(AX)
MOVQ (AX), AX
MOVQ R9, 24(AX)
MOVQ R10, 32(AX)
MOVB R11, 40(AX)
RET
// Report error
error_max_decoded_size_exceeded:
MOVQ ctx+0(FP), AX
MOVQ $-1, CX
MOVQ CX, 40(AX)
RET
// func decompress1x_main_loop_bmi2(ctx *decompress1xContext)
// Requires: BMI2
TEXT ·decompress1x_main_loop_bmi2(SB), $0-8
MOVQ ctx+0(FP), CX
MOVQ 16(CX), DX
MOVQ 24(CX), BX
CMPQ BX, $0x04
JB error_max_decoded_size_exceeded
LEAQ (DX)(BX*1), BX
MOVQ (CX), SI
MOVQ (SI), R8
MOVQ 24(SI), R9
MOVQ 32(SI), R10
MOVBQZX 40(SI), R11
MOVQ 32(CX), SI
MOVBQZX 8(CX), DI
JMP loop_condition
main_loop:
// Check if we have room for 4 bytes in the output buffer
LEAQ 4(DX), CX
CMPQ CX, BX
JGE error_max_decoded_size_exceeded
// Decode 4 values
CMPQ R11, $0x20
JL bitReader_fillFast_1_end
SUBQ $0x20, R11
SUBQ $0x04, R9
MOVL (R8)(R9*1), CX
SHLXQ R11, CX, CX
ORQ CX, R10
bitReader_fillFast_1_end:
SHRXQ DI, R10, CX
MOVW (SI)(CX*2), CX
MOVB CH, AL
MOVBQZX CL, CX
ADDQ CX, R11
SHLXQ CX, R10, R10
SHRXQ DI, R10, CX
MOVW (SI)(CX*2), CX
MOVB CH, AH
MOVBQZX CL, CX
ADDQ CX, R11
SHLXQ CX, R10, R10
BSWAPL AX
CMPQ R11, $0x20
JL bitReader_fillFast_2_end
SUBQ $0x20, R11
SUBQ $0x04, R9
MOVL (R8)(R9*1), CX
SHLXQ R11, CX, CX
ORQ CX, R10
bitReader_fillFast_2_end:
SHRXQ DI, R10, CX
MOVW (SI)(CX*2), CX
MOVB CH, AH
MOVBQZX CL, CX
ADDQ CX, R11
SHLXQ CX, R10, R10
SHRXQ DI, R10, CX
MOVW (SI)(CX*2), CX
MOVB CH, AL
MOVBQZX CL, CX
ADDQ CX, R11
SHLXQ CX, R10, R10
BSWAPL AX
// Store the decoded values
MOVL AX, (DX)
ADDQ $0x04, DX
loop_condition:
CMPQ R9, $0x08
JGE main_loop
// Update ctx structure
MOVQ ctx+0(FP), AX
SUBQ 16(AX), DX
MOVQ DX, 40(AX)
MOVQ (AX), AX
MOVQ R9, 24(AX)
MOVQ R10, 32(AX)
MOVB R11, 40(AX)
RET
// Report error
error_max_decoded_size_exceeded:
MOVQ ctx+0(FP), AX
MOVQ $-1, CX
MOVQ CX, 40(AX)
RET
Server/vendor/github.com/klauspost/compress/huff0/decompress_generic.go
Generated Vendored
+298
View File
@@ -0,0 +1,298 @@
//go:build !amd64 || appengine || !gc || noasm
// This file contains a generic implementation of Decoder.Decompress4X.
package huff0
import (
"errors"
"fmt"
)
// Decompress4X will decompress a 4X encoded stream.
// The length of the supplied input must match the end of a block exactly.
// The *capacity* of the dst slice must match the destination size of
// the uncompressed data exactly.
func (d *Decoder) Decompress4X(dst, src []byte) ([]byte, error) {
if len(d.dt.single) == 0 {
return nil, errors.New("no table loaded")
}
if len(src) < 6+(4*1) {
return nil, errors.New("input too small")
}
if use8BitTables && d.actualTableLog <= 8 {
return d.decompress4X8bit(dst, src)
}
var br [4]bitReaderShifted
// Decode "jump table"
start := 6
for i := 0; i < 3; i++ {
length := int(src[i*2]) | (int(src[i*2+1]) << 8)
if start+length >= len(src) {
return nil, errors.New("truncated input (or invalid offset)")
}
err := br[i].init(src[start : start+length])
if err != nil {
return nil, err
}
start += length
}
err := br[3].init(src[start:])
if err != nil {
return nil, err
}
// destination, offset to match first output
dstSize := cap(dst)
dst = dst[:dstSize]
out := dst
dstEvery := (dstSize + 3) / 4
const tlSize = 1 << tableLogMax
const tlMask = tlSize - 1
single := d.dt.single[:tlSize]
// Use temp table to avoid bound checks/append penalty.
buf := d.buffer()
var off uint8
var decoded int
// Decode 2 values from each decoder/loop.
const bufoff = 256
for {
if br[0].off < 4 || br[1].off < 4 || br[2].off < 4 || br[3].off < 4 {
break
}
{
const stream = 0
const stream2 = 1
br[stream].fillFast()
br[stream2].fillFast()
val := br[stream].peekBitsFast(d.actualTableLog)
val2 := br[stream2].peekBitsFast(d.actualTableLog)
v := single[val&tlMask]
v2 := single[val2&tlMask]
br[stream].advance(uint8(v.entry))
br[stream2].advance(uint8(v2.entry))
buf[stream][off] = uint8(v.entry >> 8)
buf[stream2][off] = uint8(v2.entry >> 8)
val = br[stream].peekBitsFast(d.actualTableLog)
val2 = br[stream2].peekBitsFast(d.actualTableLog)
v = single[val&tlMask]
v2 = single[val2&tlMask]
br[stream].advance(uint8(v.entry))
br[stream2].advance(uint8(v2.entry))
buf[stream][off+1] = uint8(v.entry >> 8)
buf[stream2][off+1] = uint8(v2.entry >> 8)
}
{
const stream = 2
const stream2 = 3
br[stream].fillFast()
br[stream2].fillFast()
val := br[stream].peekBitsFast(d.actualTableLog)
val2 := br[stream2].peekBitsFast(d.actualTableLog)
v := single[val&tlMask]
v2 := single[val2&tlMask]
br[stream].advance(uint8(v.entry))
br[stream2].advance(uint8(v2.entry))
buf[stream][off] = uint8(v.entry >> 8)
buf[stream2][off] = uint8(v2.entry >> 8)
val = br[stream].peekBitsFast(d.actualTableLog)
val2 = br[stream2].peekBitsFast(d.actualTableLog)
v = single[val&tlMask]
v2 = single[val2&tlMask]
br[stream].advance(uint8(v.entry))
br[stream2].advance(uint8(v2.entry))
buf[stream][off+1] = uint8(v.entry >> 8)
buf[stream2][off+1] = uint8(v2.entry >> 8)
}
off += 2
if off == 0 {
if bufoff > dstEvery {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 1")
}
// There must at least be 3 buffers left.
if len(out)-bufoff < dstEvery*3 {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 2")
}
//copy(out, buf[0][:])
//copy(out[dstEvery:], buf[1][:])
//copy(out[dstEvery*2:], buf[2][:])
//copy(out[dstEvery*3:], buf[3][:])
*(*[bufoff]byte)(out) = buf[0]
*(*[bufoff]byte)(out[dstEvery:]) = buf[1]
*(*[bufoff]byte)(out[dstEvery*2:]) = buf[2]
*(*[bufoff]byte)(out[dstEvery*3:]) = buf[3]
out = out[bufoff:]
decoded += bufoff * 4
}
}
if off > 0 {
ioff := int(off)
if len(out) < dstEvery*3+ioff {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 3")
}
copy(out, buf[0][:off])
copy(out[dstEvery:], buf[1][:off])
copy(out[dstEvery*2:], buf[2][:off])
copy(out[dstEvery*3:], buf[3][:off])
decoded += int(off) * 4
out = out[off:]
}
// Decode remaining.
remainBytes := dstEvery - (decoded / 4)
for i := range br {
offset := dstEvery * i
endsAt := offset + remainBytes
if endsAt > len(out) {
endsAt = len(out)
}
br := &br[i]
bitsLeft := br.remaining()
for bitsLeft > 0 {
br.fill()
if offset >= endsAt {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 4")
}
// Read value and increment offset.
val := br.peekBitsFast(d.actualTableLog)
v := single[val&tlMask].entry
nBits := uint8(v)
br.advance(nBits)
bitsLeft -= uint(nBits)
out[offset] = uint8(v >> 8)
offset++
}
if offset != endsAt {
d.bufs.Put(buf)
return nil, fmt.Errorf("corruption detected: short output block %d, end %d != %d", i, offset, endsAt)
}
decoded += offset - dstEvery*i
err = br.close()
if err != nil {
return nil, err
}
}
d.bufs.Put(buf)
if dstSize != decoded {
return nil, errors.New("corruption detected: short output block")
}
return dst, nil
}
// Decompress1X will decompress a 1X encoded stream.
// The cap of the output buffer will be the maximum decompressed size.
// The length of the supplied input must match the end of a block exactly.
func (d *Decoder) Decompress1X(dst, src []byte) ([]byte, error) {
if len(d.dt.single) == 0 {
return nil, errors.New("no table loaded")
}
if use8BitTables && d.actualTableLog <= 8 {
return d.decompress1X8Bit(dst, src)
}
var br bitReaderShifted
err := br.init(src)
if err != nil {
return dst, err
}
maxDecodedSize := cap(dst)
dst = dst[:0]
// Avoid bounds check by always having full sized table.
const tlSize = 1 << tableLogMax
const tlMask = tlSize - 1
dt := d.dt.single[:tlSize]
// Use temp table to avoid bound checks/append penalty.
bufs := d.buffer()
buf := &bufs[0]
var off uint8
for br.off >= 8 {
br.fillFast()
v := dt[br.peekBitsFast(d.actualTableLog)&tlMask]
br.advance(uint8(v.entry))
buf[off+0] = uint8(v.entry >> 8)
v = dt[br.peekBitsFast(d.actualTableLog)&tlMask]
br.advance(uint8(v.entry))
buf[off+1] = uint8(v.entry >> 8)
// Refill
br.fillFast()
v = dt[br.peekBitsFast(d.actualTableLog)&tlMask]
br.advance(uint8(v.entry))
buf[off+2] = uint8(v.entry >> 8)
v = dt[br.peekBitsFast(d.actualTableLog)&tlMask]
br.advance(uint8(v.entry))
buf[off+3] = uint8(v.entry >> 8)
off += 4
if off == 0 {
if len(dst)+256 > maxDecodedSize {
br.close()
d.bufs.Put(bufs)
return nil, ErrMaxDecodedSizeExceeded
}
dst = append(dst, buf[:]...)
}
}
if len(dst)+int(off) > maxDecodedSize {
d.bufs.Put(bufs)
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
dst = append(dst, buf[:off]...)
// br < 8, so uint8 is fine
bitsLeft := uint8(br.off)*8 + 64 - br.bitsRead
for bitsLeft > 0 {
br.fill()
if false && br.bitsRead >= 32 {
if br.off >= 4 {
v := br.in[br.off-4:]
v = v[:4]
low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
br.value = (br.value << 32) | uint64(low)
br.bitsRead -= 32
br.off -= 4
} else {
for br.off > 0 {
br.value = (br.value << 8) | uint64(br.in[br.off-1])
br.bitsRead -= 8
br.off--
}
}
}
if len(dst) >= maxDecodedSize {
d.bufs.Put(bufs)
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
v := d.dt.single[br.peekBitsFast(d.actualTableLog)&tlMask]
nBits := uint8(v.entry)
br.advance(nBits)
bitsLeft -= nBits
dst = append(dst, uint8(v.entry>>8))
}
d.bufs.Put(bufs)
return dst, br.close()
}
Server/vendor/github.com/klauspost/compress/huff0/huff0.go
Generated Vendored
+337
View File
@@ -0,0 +1,337 @@
// Package huff0 provides fast huffman encoding as used in zstd.
//
// See README.md at https://github.com/klauspost/compress/tree/master/huff0 for details.
package huff0
import (
"errors"
"fmt"
"math"
"math/bits"
"sync"
"github.com/klauspost/compress/fse"
)
const (
maxSymbolValue = 255
// zstandard limits tablelog to 11, see:
// https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#huffman-tree-description
tableLogMax = 11
tableLogDefault = 11
minTablelog = 5
huffNodesLen = 512
// BlockSizeMax is maximum input size for a single block uncompressed.
BlockSizeMax = 1<<18 - 1
)
var (
// ErrIncompressible is returned when input is judged to be too hard to compress.
ErrIncompressible = errors.New("input is not compressible")
// ErrUseRLE is returned from the compressor when the input is a single byte value repeated.
ErrUseRLE = errors.New("input is single value repeated")
// ErrTooBig is return if input is too large for a single block.
ErrTooBig = errors.New("input too big")
// ErrMaxDecodedSizeExceeded is return if input is too large for a single block.
ErrMaxDecodedSizeExceeded = errors.New("maximum output size exceeded")
)
type ReusePolicy uint8
const (
// ReusePolicyAllow will allow reuse if it produces smaller output.
ReusePolicyAllow ReusePolicy = iota
// ReusePolicyPrefer will re-use aggressively if possible.
// This will not check if a new table will produce smaller output,
// except if the current table is impossible to use or
// compressed output is bigger than input.
ReusePolicyPrefer
// ReusePolicyNone will disable re-use of tables.
// This is slightly faster than ReusePolicyAllow but may produce larger output.
ReusePolicyNone
// ReusePolicyMust must allow reuse and produce smaller output.
ReusePolicyMust
)
type Scratch struct {
count [maxSymbolValue + 1]uint32
// Per block parameters.
// These can be used to override compression parameters of the block.
// Do not touch, unless you know what you are doing.
// Out is output buffer.
// If the scratch is re-used before the caller is done processing the output,
// set this field to nil.
// Otherwise the output buffer will be re-used for next Compression/Decompression step
// and allocation will be avoided.
Out []byte
// OutTable will contain the table data only, if a new table has been generated.
// Slice of the returned data.
OutTable []byte
// OutData will contain the compressed data.
// Slice of the returned data.
OutData []byte
// MaxDecodedSize will set the maximum allowed output size.
// This value will automatically be set to BlockSizeMax if not set.
// Decoders will return ErrMaxDecodedSizeExceeded is this limit is exceeded.
MaxDecodedSize int
srcLen int
// MaxSymbolValue will override the maximum symbol value of the next block.
MaxSymbolValue uint8
// TableLog will attempt to override the tablelog for the next block.
// Must be <= 11 and >= 5.
TableLog uint8
// Reuse will specify the reuse policy
Reuse ReusePolicy
// WantLogLess allows to specify a log 2 reduction that should at least be achieved,
// otherwise the block will be returned as incompressible.
// The reduction should then at least be (input size >> WantLogLess)
// If WantLogLess == 0 any improvement will do.
WantLogLess uint8
symbolLen uint16 // Length of active part of the symbol table.
maxCount int // count of the most probable symbol
clearCount bool // clear count
actualTableLog uint8 // Selected tablelog.
prevTableLog uint8 // Tablelog for previous table
prevTable cTable // Table used for previous compression.
cTable cTable // compression table
dt dTable // decompression table
nodes []nodeElt
tmpOut [4][]byte
fse *fse.Scratch
decPool sync.Pool // *[4][256]byte buffers.
huffWeight [maxSymbolValue + 1]byte
}
// TransferCTable will transfer the previously used compression table.
func (s *Scratch) TransferCTable(src *Scratch) {
if cap(s.prevTable) < len(src.prevTable) {
s.prevTable = make(cTable, 0, maxSymbolValue+1)
}
s.prevTable = s.prevTable[:len(src.prevTable)]
copy(s.prevTable, src.prevTable)
s.prevTableLog = src.prevTableLog
}
func (s *Scratch) prepare(in []byte) (*Scratch, error) {
if len(in) > BlockSizeMax {
return nil, ErrTooBig
}
if s == nil {
s = &Scratch{}
}
if s.MaxSymbolValue == 0 {
s.MaxSymbolValue = maxSymbolValue
}
if s.TableLog == 0 {
s.TableLog = tableLogDefault
}
if s.TableLog > tableLogMax || s.TableLog < minTablelog {
return nil, fmt.Errorf(" invalid tableLog %d (%d -> %d)", s.TableLog, minTablelog, tableLogMax)
}
if s.MaxDecodedSize <= 0 || s.MaxDecodedSize > BlockSizeMax {
s.MaxDecodedSize = BlockSizeMax
}
if s.clearCount && s.maxCount == 0 {
for i := range s.count {
s.count[i] = 0
}
s.clearCount = false
}
if cap(s.Out) == 0 {
s.Out = make([]byte, 0, len(in))
}
s.Out = s.Out[:0]
s.OutTable = nil
s.OutData = nil
if cap(s.nodes) < huffNodesLen+1 {
s.nodes = make([]nodeElt, 0, huffNodesLen+1)
}
s.nodes = s.nodes[:0]
if s.fse == nil {
s.fse = &fse.Scratch{}
}
s.srcLen = len(in)
return s, nil
}
type cTable []cTableEntry
func (c cTable) write(s *Scratch) error {
var (
// precomputed conversion table
bitsToWeight [tableLogMax + 1]byte
huffLog = s.actualTableLog
// last weight is not saved.
maxSymbolValue = uint8(s.symbolLen - 1)
huffWeight = s.huffWeight[:256]
)
const (
maxFSETableLog = 6
)
// convert to weight
bitsToWeight[0] = 0
for n := uint8(1); n < huffLog+1; n++ {
bitsToWeight[n] = huffLog + 1 - n
}
// Acquire histogram for FSE.
hist := s.fse.Histogram()
hist = hist[:256]
for i := range hist[:16] {
hist[i] = 0
}
for n := range maxSymbolValue {
v := bitsToWeight[c[n].nBits] & 15
huffWeight[n] = v
hist[v]++
}
// FSE compress if feasible.
if maxSymbolValue >= 2 {
huffMaxCnt := uint32(0)
huffMax := uint8(0)
for i, v := range hist[:16] {
if v == 0 {
continue
}
huffMax = byte(i)
if v > huffMaxCnt {
huffMaxCnt = v
}
}
s.fse.HistogramFinished(huffMax, int(huffMaxCnt))
s.fse.TableLog = maxFSETableLog
b, err := fse.Compress(huffWeight[:maxSymbolValue], s.fse)
if err == nil && len(b) < int(s.symbolLen>>1) {
s.Out = append(s.Out, uint8(len(b)))
s.Out = append(s.Out, b...)
return nil
}
// Unable to compress (RLE/uncompressible)
}
// write raw values as 4-bits (max : 15)
if maxSymbolValue > (256 - 128) {
// should not happen : likely means source cannot be compressed
return ErrIncompressible
}
op := s.Out
// special case, pack weights 4 bits/weight.
op = append(op, 128|(maxSymbolValue-1))
// be sure it doesn't cause msan issue in final combination
huffWeight[maxSymbolValue] = 0
for n := uint16(0); n < uint16(maxSymbolValue); n += 2 {
op = append(op, (huffWeight[n]<<4)|huffWeight[n+1])
}
s.Out = op
return nil
}
func (c cTable) estTableSize(s *Scratch) (sz int, err error) {
var (
// precomputed conversion table
bitsToWeight [tableLogMax + 1]byte
huffLog = s.actualTableLog
// last weight is not saved.
maxSymbolValue = uint8(s.symbolLen - 1)
huffWeight = s.huffWeight[:256]
)
const (
maxFSETableLog = 6
)
// convert to weight
bitsToWeight[0] = 0
for n := uint8(1); n < huffLog+1; n++ {
bitsToWeight[n] = huffLog + 1 - n
}
// Acquire histogram for FSE.
hist := s.fse.Histogram()
hist = hist[:256]
for i := range hist[:16] {
hist[i] = 0
}
for n := range maxSymbolValue {
v := bitsToWeight[c[n].nBits] & 15
huffWeight[n] = v
hist[v]++
}
// FSE compress if feasible.
if maxSymbolValue >= 2 {
huffMaxCnt := uint32(0)
huffMax := uint8(0)
for i, v := range hist[:16] {
if v == 0 {
continue
}
huffMax = byte(i)
if v > huffMaxCnt {
huffMaxCnt = v
}
}
s.fse.HistogramFinished(huffMax, int(huffMaxCnt))
s.fse.TableLog = maxFSETableLog
b, err := fse.Compress(huffWeight[:maxSymbolValue], s.fse)
if err == nil && len(b) < int(s.symbolLen>>1) {
sz += 1 + len(b)
return sz, nil
}
// Unable to compress (RLE/uncompressible)
}
// write raw values as 4-bits (max : 15)
if maxSymbolValue > (256 - 128) {
// should not happen : likely means source cannot be compressed
return 0, ErrIncompressible
}
// special case, pack weights 4 bits/weight.
sz += 1 + int(maxSymbolValue/2)
return sz, nil
}
// estimateSize returns the estimated size in bytes of the input represented in the
// histogram supplied.
func (c cTable) estimateSize(hist []uint32) int {
nbBits := uint32(7)
for i, v := range c[:len(hist)] {
nbBits += uint32(v.nBits) * hist[i]
}
return int(nbBits >> 3)
}
// minSize returns the minimum possible size considering the shannon limit.
func (s *Scratch) minSize(total int) int {
nbBits := float64(7)
fTotal := float64(total)
for _, v := range s.count[:s.symbolLen] {
n := float64(v)
if n > 0 {
nbBits += math.Log2(fTotal/n) * n
}
}
return int(nbBits) >> 3
}
func highBit32(val uint32) (n uint32) {
return uint32(bits.Len32(val) - 1)
}
Server/vendor/github.com/klauspost/compress/internal/cpuinfo/cpuinfo.go
Generated Vendored
+34
View File
@@ -0,0 +1,34 @@
// Package cpuinfo gives runtime info about the current CPU.
//
// This is a very limited module meant for use internally
// in this project. For more versatile solution check
// https://github.com/klauspost/cpuid.
package cpuinfo
// HasBMI1 checks whether an x86 CPU supports the BMI1 extension.
func HasBMI1() bool {
return hasBMI1
}
// HasBMI2 checks whether an x86 CPU supports the BMI2 extension.
func HasBMI2() bool {
return hasBMI2
}
// DisableBMI2 will disable BMI2, for testing purposes.
// Call returned function to restore previous state.
func DisableBMI2() func() {
old := hasBMI2
hasBMI2 = false
return func() {
hasBMI2 = old
}
}
// HasBMI checks whether an x86 CPU supports both BMI1 and BMI2 extensions.
func HasBMI() bool {
return HasBMI1() && HasBMI2()
}
var hasBMI1 bool
var hasBMI2 bool
Server/vendor/github.com/klauspost/compress/internal/cpuinfo/cpuinfo_amd64.go
Generated Vendored
+10
View File
@@ -0,0 +1,10 @@
//go:build amd64 && !appengine && !noasm && gc
package cpuinfo
// go:noescape
func x86extensions() (bmi1, bmi2 bool)
func init() {
hasBMI1, hasBMI2 = x86extensions()
}
Server/vendor/github.com/klauspost/compress/internal/cpuinfo/cpuinfo_amd64.s
Generated Vendored
+36
View File
@@ -0,0 +1,36 @@
// +build !appengine
// +build gc
// +build !noasm
#include "textflag.h"
#include "funcdata.h"
#include "go_asm.h"
TEXT ·x86extensions(SB), NOSPLIT, $0
// 1. determine max EAX value
XORQ AX, AX
CPUID
CMPQ AX, $7
JB unsupported
// 2. EAX = 7, ECX = 0 --- see Table 3-8 "Information Returned by CPUID Instruction"
MOVQ $7, AX
MOVQ $0, CX
CPUID
BTQ $3, BX // bit 3 = BMI1
SETCS AL
BTQ $8, BX // bit 8 = BMI2
SETCS AH
MOVB AL, bmi1+0(FP)
MOVB AH, bmi2+1(FP)
RET
unsupported:
XORQ AX, AX
MOVB AL, bmi1+0(FP)
MOVB AL, bmi2+1(FP)
RET
Server/vendor/github.com/klauspost/compress/internal/le/le.go
Generated Vendored
+5
View File
@@ -0,0 +1,5 @@
package le
type Indexer interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64
}
Server/vendor/github.com/klauspost/compress/internal/le/unsafe_disabled.go
Generated Vendored
+42
View File
@@ -0,0 +1,42 @@
//go:build !(amd64 || arm64 || ppc64le || riscv64) || nounsafe || purego || appengine
package le
import (
"encoding/binary"
)
// Load8 will load from b at index i.
func Load8[I Indexer](b []byte, i I) byte {
return b[i]
}
// Load16 will load from b at index i.
func Load16[I Indexer](b []byte, i I) uint16 {
return binary.LittleEndian.Uint16(b[i:])
}
// Load32 will load from b at index i.
func Load32[I Indexer](b []byte, i I) uint32 {
return binary.LittleEndian.Uint32(b[i:])
}
// Load64 will load from b at index i.
func Load64[I Indexer](b []byte, i I) uint64 {
return binary.LittleEndian.Uint64(b[i:])
}
// Store16 will store v at b.
func Store16(b []byte, v uint16) {
binary.LittleEndian.PutUint16(b, v)
}
// Store32 will store v at b.
func Store32(b []byte, v uint32) {
binary.LittleEndian.PutUint32(b, v)
}
// Store64 will store v at b.
func Store64[I Indexer](b []byte, i I, v uint64) {
binary.LittleEndian.PutUint64(b[i:], v)
}
Server/vendor/github.com/klauspost/compress/internal/le/unsafe_enabled.go
Generated Vendored
+52
View File
@@ -0,0 +1,52 @@
// We enable 64 bit LE platforms:
//go:build (amd64 || arm64 || ppc64le || riscv64) && !nounsafe && !purego && !appengine
package le
import (
"unsafe"
)
// Load8 will load from b at index i.
func Load8[I Indexer](b []byte, i I) byte {
//return binary.LittleEndian.Uint16(b[i:])
//return *(*uint16)(unsafe.Pointer(&b[i]))
return *(*byte)(unsafe.Add(unsafe.Pointer(unsafe.SliceData(b)), i))
}
// Load16 will load from b at index i.
func Load16[I Indexer](b []byte, i I) uint16 {
//return binary.LittleEndian.Uint16(b[i:])
//return *(*uint16)(unsafe.Pointer(&b[i]))
return *(*uint16)(unsafe.Add(unsafe.Pointer(unsafe.SliceData(b)), i))
}
// Load32 will load from b at index i.
func Load32[I Indexer](b []byte, i I) uint32 {
//return binary.LittleEndian.Uint32(b[i:])
//return *(*uint32)(unsafe.Pointer(&b[i]))
return *(*uint32)(unsafe.Add(unsafe.Pointer(unsafe.SliceData(b)), i))
}
// Load64 will load from b at index i.
func Load64[I Indexer](b []byte, i I) uint64 {
//return binary.LittleEndian.Uint64(b[i:])
//return *(*uint64)(unsafe.Pointer(&b[i]))
return *(*uint64)(unsafe.Add(unsafe.Pointer(unsafe.SliceData(b)), i))
}
// Store16 will store v at b.
func Store16(b []byte, v uint16) {
*(*uint16)(unsafe.Pointer(unsafe.SliceData(b))) = v
}
// Store32 will store v at b.
func Store32(b []byte, v uint32) {
*(*uint32)(unsafe.Pointer(unsafe.SliceData(b))) = v
}
// Store64 will store v at b[i:].
func Store64[I Indexer](b []byte, i I, v uint64) {
*(*uint64)(unsafe.Add(unsafe.Pointer(unsafe.SliceData(b)), i)) = v
}
Server/vendor/github.com/klauspost/compress/internal/race/norace.go
Generated Vendored
+13
View File
@@ -0,0 +1,13 @@
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build !race
package race
func ReadSlice[T any](s []T) {
}
func WriteSlice[T any](s []T) {
}
Server/vendor/github.com/klauspost/compress/internal/race/race.go
Generated Vendored
+26
View File
@@ -0,0 +1,26 @@
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build race
package race
import (
"runtime"
"unsafe"
)
func ReadSlice[T any](s []T) {
if len(s) == 0 {
return
}
runtime.RaceReadRange(unsafe.Pointer(&s[0]), len(s)*int(unsafe.Sizeof(s[0])))
}
func WriteSlice[T any](s []T) {
if len(s) == 0 {
return
}
runtime.RaceWriteRange(unsafe.Pointer(&s[0]), len(s)*int(unsafe.Sizeof(s[0])))
}
Server/vendor/github.com/klauspost/compress/internal/snapref/LICENSE
Generated Vendored
+27
View File
@@ -0,0 +1,27 @@
Copyright (c) 2011 The Snappy-Go Authors. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Server/vendor/github.com/klauspost/compress/internal/snapref/decode.go
Generated Vendored
+264
View File
@@ -0,0 +1,264 @@
// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package snapref
import (
"encoding/binary"
"errors"
"io"
)
var (
// ErrCorrupt reports that the input is invalid.
ErrCorrupt = errors.New("snappy: corrupt input")
// ErrTooLarge reports that the uncompressed length is too large.
ErrTooLarge = errors.New("snappy: decoded block is too large")
// ErrUnsupported reports that the input isn't supported.
ErrUnsupported = errors.New("snappy: unsupported input")
errUnsupportedLiteralLength = errors.New("snappy: unsupported literal length")
)
// DecodedLen returns the length of the decoded block.
func DecodedLen(src []byte) (int, error) {
v, _, err := decodedLen(src)
return v, err
}
// decodedLen returns the length of the decoded block and the number of bytes
// that the length header occupied.
func decodedLen(src []byte) (blockLen, headerLen int, err error) {
v, n := binary.Uvarint(src)
if n <= 0 || v > 0xffffffff {
return 0, 0, ErrCorrupt
}
const wordSize = 32 << (^uint(0) >> 32 & 1)
if wordSize == 32 && v > 0x7fffffff {
return 0, 0, ErrTooLarge
}
return int(v), n, nil
}
const (
decodeErrCodeCorrupt = 1
decodeErrCodeUnsupportedLiteralLength = 2
)
// Decode returns the decoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire decoded block.
// Otherwise, a newly allocated slice will be returned.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// Decode handles the Snappy block format, not the Snappy stream format.
func Decode(dst, src []byte) ([]byte, error) {
dLen, s, err := decodedLen(src)
if err != nil {
return nil, err
}
if dLen <= len(dst) {
dst = dst[:dLen]
} else {
dst = make([]byte, dLen)
}
switch decode(dst, src[s:]) {
case 0:
return dst, nil
case decodeErrCodeUnsupportedLiteralLength:
return nil, errUnsupportedLiteralLength
}
return nil, ErrCorrupt
}
// NewReader returns a new Reader that decompresses from r, using the framing
// format described at
// https://github.com/google/snappy/blob/master/framing_format.txt
func NewReader(r io.Reader) *Reader {
return &Reader{
r: r,
decoded: make([]byte, maxBlockSize),
buf: make([]byte, maxEncodedLenOfMaxBlockSize+checksumSize),
}
}
// Reader is an io.Reader that can read Snappy-compressed bytes.
//
// Reader handles the Snappy stream format, not the Snappy block format.
type Reader struct {
r io.Reader
err error
decoded []byte
buf []byte
// decoded[i:j] contains decoded bytes that have not yet been passed on.
i, j int
readHeader bool
}
// Reset discards any buffered data, resets all state, and switches the Snappy
// reader to read from r. This permits reusing a Reader rather than allocating
// a new one.
func (r *Reader) Reset(reader io.Reader) {
r.r = reader
r.err = nil
r.i = 0
r.j = 0
r.readHeader = false
}
func (r *Reader) readFull(p []byte, allowEOF bool) (ok bool) {
if _, r.err = io.ReadFull(r.r, p); r.err != nil {
if r.err == io.ErrUnexpectedEOF || (r.err == io.EOF && !allowEOF) {
r.err = ErrCorrupt
}
return false
}
return true
}
func (r *Reader) fill() error {
for r.i >= r.j {
if !r.readFull(r.buf[:4], true) {
return r.err
}
chunkType := r.buf[0]
if !r.readHeader {
if chunkType != chunkTypeStreamIdentifier {
r.err = ErrCorrupt
return r.err
}
r.readHeader = true
}
chunkLen := int(r.buf[1]) | int(r.buf[2])<<8 | int(r.buf[3])<<16
if chunkLen > len(r.buf) {
r.err = ErrUnsupported
return r.err
}
// The chunk types are specified at
// https://github.com/google/snappy/blob/master/framing_format.txt
switch chunkType {
case chunkTypeCompressedData:
// Section 4.2. Compressed data (chunk type 0x00).
if chunkLen < checksumSize {
r.err = ErrCorrupt
return r.err
}
buf := r.buf[:chunkLen]
if !r.readFull(buf, false) {
return r.err
}
checksum := uint32(buf[0]) | uint32(buf[1])<<8 | uint32(buf[2])<<16 | uint32(buf[3])<<24
buf = buf[checksumSize:]
n, err := DecodedLen(buf)
if err != nil {
r.err = err
return r.err
}
if n > len(r.decoded) {
r.err = ErrCorrupt
return r.err
}
if _, err := Decode(r.decoded, buf); err != nil {
r.err = err
return r.err
}
if crc(r.decoded[:n]) != checksum {
r.err = ErrCorrupt
return r.err
}
r.i, r.j = 0, n
continue
case chunkTypeUncompressedData:
// Section 4.3. Uncompressed data (chunk type 0x01).
if chunkLen < checksumSize {
r.err = ErrCorrupt
return r.err
}
buf := r.buf[:checksumSize]
if !r.readFull(buf, false) {
return r.err
}
checksum := uint32(buf[0]) | uint32(buf[1])<<8 | uint32(buf[2])<<16 | uint32(buf[3])<<24
// Read directly into r.decoded instead of via r.buf.
n := chunkLen - checksumSize
if n > len(r.decoded) {
r.err = ErrCorrupt
return r.err
}
if !r.readFull(r.decoded[:n], false) {
return r.err
}
if crc(r.decoded[:n]) != checksum {
r.err = ErrCorrupt
return r.err
}
r.i, r.j = 0, n
continue
case chunkTypeStreamIdentifier:
// Section 4.1. Stream identifier (chunk type 0xff).
if chunkLen != len(magicBody) {
r.err = ErrCorrupt
return r.err
}
if !r.readFull(r.buf[:len(magicBody)], false) {
return r.err
}
for i := range len(magicBody) {
if r.buf[i] != magicBody[i] {
r.err = ErrCorrupt
return r.err
}
}
continue
}
if chunkType <= 0x7f {
// Section 4.5. Reserved unskippable chunks (chunk types 0x02-0x7f).
r.err = ErrUnsupported
return r.err
}
// Section 4.4 Padding (chunk type 0xfe).
// Section 4.6. Reserved skippable chunks (chunk types 0x80-0xfd).
if !r.readFull(r.buf[:chunkLen], false) {
return r.err
}
}
return nil
}
// Read satisfies the io.Reader interface.
func (r *Reader) Read(p []byte) (int, error) {
if r.err != nil {
return 0, r.err
}
if err := r.fill(); err != nil {
return 0, err
}
n := copy(p, r.decoded[r.i:r.j])
r.i += n
return n, nil
}
// ReadByte satisfies the io.ByteReader interface.
func (r *Reader) ReadByte() (byte, error) {
if r.err != nil {
return 0, r.err
}
if err := r.fill(); err != nil {
return 0, err
}
c := r.decoded[r.i]
r.i++
return c, nil
}
Server/vendor/github.com/klauspost/compress/internal/snapref/decode_other.go
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+113
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@@ -0,0 +1,113 @@
// Copyright 2016 The Snappy-Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package snapref
// decode writes the decoding of src to dst. It assumes that the varint-encoded
// length of the decompressed bytes has already been read, and that len(dst)
// equals that length.
//
// It returns 0 on success or a decodeErrCodeXxx error code on failure.
func decode(dst, src []byte) int {
var d, s, offset, length int
for s < len(src) {
switch src[s] & 0x03 {
case tagLiteral:
x := uint32(src[s] >> 2)
switch {
case x < 60:
s++
case x == 60:
s += 2
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
x = uint32(src[s-1])
case x == 61:
s += 3
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
x = uint32(src[s-2]) | uint32(src[s-1])<<8
case x == 62:
s += 4
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
case x == 63:
s += 5
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
}
length = int(x) + 1
if length <= 0 {
return decodeErrCodeUnsupportedLiteralLength
}
if length > len(dst)-d || length > len(src)-s {
return decodeErrCodeCorrupt
}
copy(dst[d:], src[s:s+length])
d += length
s += length
continue
case tagCopy1:
s += 2
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = 4 + int(src[s-2])>>2&0x7
offset = int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
case tagCopy2:
s += 3
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = 1 + int(src[s-3])>>2
offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
case tagCopy4:
s += 5
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = 1 + int(src[s-5])>>2
offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
}
if offset <= 0 || d < offset || length > len(dst)-d {
return decodeErrCodeCorrupt
}
// Copy from an earlier sub-slice of dst to a later sub-slice.
// If no overlap, use the built-in copy:
if offset >= length {
copy(dst[d:d+length], dst[d-offset:])
d += length
continue
}
// Unlike the built-in copy function, this byte-by-byte copy always runs
// forwards, even if the slices overlap. Conceptually, this is:
//
// d += forwardCopy(dst[d:d+length], dst[d-offset:])
//
// We align the slices into a and b and show the compiler they are the same size.
// This allows the loop to run without bounds checks.
a := dst[d : d+length]
b := dst[d-offset:]
b = b[:len(a)]
for i := range a {
a[i] = b[i]
}
d += length
}
if d != len(dst) {
return decodeErrCodeCorrupt
}
return 0
}
Server/vendor/github.com/klauspost/compress/internal/snapref/encode.go
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+291
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@@ -0,0 +1,291 @@
// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package snapref
import (
"encoding/binary"
"errors"
"io"
)
// Encode returns the encoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire encoded block.
// Otherwise, a newly allocated slice will be returned.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// Encode handles the Snappy block format, not the Snappy stream format.
func Encode(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if cap(dst) < n {
dst = make([]byte, n)
} else {
dst = dst[:n]
}
// The block starts with the varint-encoded length of the decompressed bytes.
d := binary.PutUvarint(dst, uint64(len(src)))
for len(src) > 0 {
p := src
src = nil
if len(p) > maxBlockSize {
p, src = p[:maxBlockSize], p[maxBlockSize:]
}
if len(p) < minNonLiteralBlockSize {
d += emitLiteral(dst[d:], p)
} else {
d += encodeBlock(dst[d:], p)
}
}
return dst[:d]
}
// inputMargin is the minimum number of extra input bytes to keep, inside
// encodeBlock's inner loop. On some architectures, this margin lets us
// implement a fast path for emitLiteral, where the copy of short (<= 16 byte)
// literals can be implemented as a single load to and store from a 16-byte
// register. That literal's actual length can be as short as 1 byte, so this
// can copy up to 15 bytes too much, but that's OK as subsequent iterations of
// the encoding loop will fix up the copy overrun, and this inputMargin ensures
// that we don't overrun the dst and src buffers.
const inputMargin = 16 - 1
// minNonLiteralBlockSize is the minimum size of the input to encodeBlock that
// could be encoded with a copy tag. This is the minimum with respect to the
// algorithm used by encodeBlock, not a minimum enforced by the file format.
//
// The encoded output must start with at least a 1 byte literal, as there are
// no previous bytes to copy. A minimal (1 byte) copy after that, generated
// from an emitCopy call in encodeBlock's main loop, would require at least
// another inputMargin bytes, for the reason above: we want any emitLiteral
// calls inside encodeBlock's main loop to use the fast path if possible, which
// requires being able to overrun by inputMargin bytes. Thus,
// minNonLiteralBlockSize equals 1 + 1 + inputMargin.
//
// The C++ code doesn't use this exact threshold, but it could, as discussed at
// https://groups.google.com/d/topic/snappy-compression/oGbhsdIJSJ8/discussion
// The difference between Go (2+inputMargin) and C++ (inputMargin) is purely an
// optimization. It should not affect the encoded form. This is tested by
// TestSameEncodingAsCppShortCopies.
const minNonLiteralBlockSize = 1 + 1 + inputMargin
// MaxEncodedLen returns the maximum length of a snappy block, given its
// uncompressed length.
//
// It will return a negative value if srcLen is too large to encode.
func MaxEncodedLen(srcLen int) int {
n := uint64(srcLen)
if n > 0xffffffff {
return -1
}
// Compressed data can be defined as:
// compressed := item* literal*
// item := literal* copy
//
// The trailing literal sequence has a space blowup of at most 62/60
// since a literal of length 60 needs one tag byte + one extra byte
// for length information.
//
// Item blowup is trickier to measure. Suppose the "copy" op copies
// 4 bytes of data. Because of a special check in the encoding code,
// we produce a 4-byte copy only if the offset is < 65536. Therefore
// the copy op takes 3 bytes to encode, and this type of item leads
// to at most the 62/60 blowup for representing literals.
//
// Suppose the "copy" op copies 5 bytes of data. If the offset is big
// enough, it will take 5 bytes to encode the copy op. Therefore the
// worst case here is a one-byte literal followed by a five-byte copy.
// That is, 6 bytes of input turn into 7 bytes of "compressed" data.
//
// This last factor dominates the blowup, so the final estimate is:
n = 32 + n + n/6
if n > 0xffffffff {
return -1
}
return int(n)
}
var errClosed = errors.New("snappy: Writer is closed")
// NewWriter returns a new Writer that compresses to w.
//
// The Writer returned does not buffer writes. There is no need to Flush or
// Close such a Writer.
//
// Deprecated: the Writer returned is not suitable for many small writes, only
// for few large writes. Use NewBufferedWriter instead, which is efficient
// regardless of the frequency and shape of the writes, and remember to Close
// that Writer when done.
func NewWriter(w io.Writer) *Writer {
return &Writer{
w: w,
obuf: make([]byte, obufLen),
}
}
// NewBufferedWriter returns a new Writer that compresses to w, using the
// framing format described at
// https://github.com/google/snappy/blob/master/framing_format.txt
//
// The Writer returned buffers writes. Users must call Close to guarantee all
// data has been forwarded to the underlying io.Writer. They may also call
// Flush zero or more times before calling Close.
func NewBufferedWriter(w io.Writer) *Writer {
return &Writer{
w: w,
ibuf: make([]byte, 0, maxBlockSize),
obuf: make([]byte, obufLen),
}
}
// Writer is an io.Writer that can write Snappy-compressed bytes.
//
// Writer handles the Snappy stream format, not the Snappy block format.
type Writer struct {
w io.Writer
err error
// ibuf is a buffer for the incoming (uncompressed) bytes.
//
// Its use is optional. For backwards compatibility, Writers created by the
// NewWriter function have ibuf == nil, do not buffer incoming bytes, and
// therefore do not need to be Flush'ed or Close'd.
ibuf []byte
// obuf is a buffer for the outgoing (compressed) bytes.
obuf []byte
// wroteStreamHeader is whether we have written the stream header.
wroteStreamHeader bool
}
// Reset discards the writer's state and switches the Snappy writer to write to
// w. This permits reusing a Writer rather than allocating a new one.
func (w *Writer) Reset(writer io.Writer) {
w.w = writer
w.err = nil
if w.ibuf != nil {
w.ibuf = w.ibuf[:0]
}
w.wroteStreamHeader = false
}
// Write satisfies the io.Writer interface.
func (w *Writer) Write(p []byte) (nRet int, errRet error) {
if w.ibuf == nil {
// Do not buffer incoming bytes. This does not perform or compress well
// if the caller of Writer.Write writes many small slices. This
// behavior is therefore deprecated, but still supported for backwards
// compatibility with code that doesn't explicitly Flush or Close.
return w.write(p)
}
// The remainder of this method is based on bufio.Writer.Write from the
// standard library.
for len(p) > (cap(w.ibuf)-len(w.ibuf)) && w.err == nil {
var n int
if len(w.ibuf) == 0 {
// Large write, empty buffer.
// Write directly from p to avoid copy.
n, _ = w.write(p)
} else {
n = copy(w.ibuf[len(w.ibuf):cap(w.ibuf)], p)
w.ibuf = w.ibuf[:len(w.ibuf)+n]
w.Flush()
}
nRet += n
p = p[n:]
}
if w.err != nil {
return nRet, w.err
}
n := copy(w.ibuf[len(w.ibuf):cap(w.ibuf)], p)
w.ibuf = w.ibuf[:len(w.ibuf)+n]
nRet += n
return nRet, nil
}
func (w *Writer) write(p []byte) (nRet int, errRet error) {
if w.err != nil {
return 0, w.err
}
for len(p) > 0 {
obufStart := len(magicChunk)
if !w.wroteStreamHeader {
w.wroteStreamHeader = true
copy(w.obuf, magicChunk)
obufStart = 0
}
var uncompressed []byte
if len(p) > maxBlockSize {
uncompressed, p = p[:maxBlockSize], p[maxBlockSize:]
} else {
uncompressed, p = p, nil
}
checksum := crc(uncompressed)
// Compress the buffer, discarding the result if the improvement
// isn't at least 12.5%.
compressed := Encode(w.obuf[obufHeaderLen:], uncompressed)
chunkType := uint8(chunkTypeCompressedData)
chunkLen := 4 + len(compressed)
obufEnd := obufHeaderLen + len(compressed)
if len(compressed) >= len(uncompressed)-len(uncompressed)/8 {
chunkType = chunkTypeUncompressedData
chunkLen = 4 + len(uncompressed)
obufEnd = obufHeaderLen
}
// Fill in the per-chunk header that comes before the body.
w.obuf[len(magicChunk)+0] = chunkType
w.obuf[len(magicChunk)+1] = uint8(chunkLen >> 0)
w.obuf[len(magicChunk)+2] = uint8(chunkLen >> 8)
w.obuf[len(magicChunk)+3] = uint8(chunkLen >> 16)
w.obuf[len(magicChunk)+4] = uint8(checksum >> 0)
w.obuf[len(magicChunk)+5] = uint8(checksum >> 8)
w.obuf[len(magicChunk)+6] = uint8(checksum >> 16)
w.obuf[len(magicChunk)+7] = uint8(checksum >> 24)
if _, err := w.w.Write(w.obuf[obufStart:obufEnd]); err != nil {
w.err = err
return nRet, err
}
if chunkType == chunkTypeUncompressedData {
if _, err := w.w.Write(uncompressed); err != nil {
w.err = err
return nRet, err
}
}
nRet += len(uncompressed)
}
return nRet, nil
}
// Flush flushes the Writer to its underlying io.Writer.
func (w *Writer) Flush() error {
if w.err != nil {
return w.err
}
if len(w.ibuf) == 0 {
return nil
}
w.write(w.ibuf)
w.ibuf = w.ibuf[:0]
return w.err
}
// Close calls Flush and then closes the Writer.
func (w *Writer) Close() error {
w.Flush()
ret := w.err
if w.err == nil {
w.err = errClosed
}
return ret
}
Server/vendor/github.com/klauspost/compress/internal/snapref/encode_other.go
Generated Vendored
+250
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@@ -0,0 +1,250 @@
// Copyright 2016 The Snappy-Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package snapref
func load32(b []byte, i int) uint32 {
b = b[i : i+4 : len(b)] // Help the compiler eliminate bounds checks on the next line.
return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
}
func load64(b []byte, i int) uint64 {
b = b[i : i+8 : len(b)] // Help the compiler eliminate bounds checks on the next line.
return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
}
// emitLiteral writes a literal chunk and returns the number of bytes written.
//
// It assumes that:
//
// dst is long enough to hold the encoded bytes
// 1 <= len(lit) && len(lit) <= 65536
func emitLiteral(dst, lit []byte) int {
i, n := 0, uint(len(lit)-1)
switch {
case n < 60:
dst[0] = uint8(n)<<2 | tagLiteral
i = 1
case n < 1<<8:
dst[0] = 60<<2 | tagLiteral
dst[1] = uint8(n)
i = 2
default:
dst[0] = 61<<2 | tagLiteral
dst[1] = uint8(n)
dst[2] = uint8(n >> 8)
i = 3
}
return i + copy(dst[i:], lit)
}
// emitCopy writes a copy chunk and returns the number of bytes written.
//
// It assumes that:
//
// dst is long enough to hold the encoded bytes
// 1 <= offset && offset <= 65535
// 4 <= length && length <= 65535
func emitCopy(dst []byte, offset, length int) int {
i := 0
// The maximum length for a single tagCopy1 or tagCopy2 op is 64 bytes. The
// threshold for this loop is a little higher (at 68 = 64 + 4), and the
// length emitted down below is a little lower (at 60 = 64 - 4), because
// it's shorter to encode a length 67 copy as a length 60 tagCopy2 followed
// by a length 7 tagCopy1 (which encodes as 3+2 bytes) than to encode it as
// a length 64 tagCopy2 followed by a length 3 tagCopy2 (which encodes as
// 3+3 bytes). The magic 4 in the 64±4 is because the minimum length for a
// tagCopy1 op is 4 bytes, which is why a length 3 copy has to be an
// encodes-as-3-bytes tagCopy2 instead of an encodes-as-2-bytes tagCopy1.
for length >= 68 {
// Emit a length 64 copy, encoded as 3 bytes.
dst[i+0] = 63<<2 | tagCopy2
dst[i+1] = uint8(offset)
dst[i+2] = uint8(offset >> 8)
i += 3
length -= 64
}
if length > 64 {
// Emit a length 60 copy, encoded as 3 bytes.
dst[i+0] = 59<<2 | tagCopy2
dst[i+1] = uint8(offset)
dst[i+2] = uint8(offset >> 8)
i += 3
length -= 60
}
if length >= 12 || offset >= 2048 {
// Emit the remaining copy, encoded as 3 bytes.
dst[i+0] = uint8(length-1)<<2 | tagCopy2
dst[i+1] = uint8(offset)
dst[i+2] = uint8(offset >> 8)
return i + 3
}
// Emit the remaining copy, encoded as 2 bytes.
dst[i+0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
dst[i+1] = uint8(offset)
return i + 2
}
func hash(u, shift uint32) uint32 {
return (u * 0x1e35a7bd) >> shift
}
// EncodeBlockInto exposes encodeBlock but checks dst size.
func EncodeBlockInto(dst, src []byte) (d int) {
if MaxEncodedLen(len(src)) > len(dst) {
return 0
}
// encodeBlock breaks on too big blocks, so split.
for len(src) > 0 {
p := src
src = nil
if len(p) > maxBlockSize {
p, src = p[:maxBlockSize], p[maxBlockSize:]
}
if len(p) < minNonLiteralBlockSize {
d += emitLiteral(dst[d:], p)
} else {
d += encodeBlock(dst[d:], p)
}
}
return d
}
// encodeBlock encodes a non-empty src to a guaranteed-large-enough dst. It
// assumes that the varint-encoded length of the decompressed bytes has already
// been written.
//
// It also assumes that:
//
// len(dst) >= MaxEncodedLen(len(src)) &&
// minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize
func encodeBlock(dst, src []byte) (d int) {
// Initialize the hash table. Its size ranges from 1<<8 to 1<<14 inclusive.
// The table element type is uint16, as s < sLimit and sLimit < len(src)
// and len(src) <= maxBlockSize and maxBlockSize == 65536.
const (
maxTableSize = 1 << 14
// tableMask is redundant, but helps the compiler eliminate bounds
// checks.
tableMask = maxTableSize - 1
)
shift := uint32(32 - 8)
for tableSize := 1 << 8; tableSize < maxTableSize && tableSize < len(src); tableSize *= 2 {
shift--
}
// In Go, all array elements are zero-initialized, so there is no advantage
// to a smaller tableSize per se. However, it matches the C++ algorithm,
// and in the asm versions of this code, we can get away with zeroing only
// the first tableSize elements.
var table [maxTableSize]uint16
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := len(src) - inputMargin
// nextEmit is where in src the next emitLiteral should start from.
nextEmit := 0
// The encoded form must start with a literal, as there are no previous
// bytes to copy, so we start looking for hash matches at s == 1.
s := 1
nextHash := hash(load32(src, s), shift)
for {
// Copied from the C++ snappy implementation:
//
// Heuristic match skipping: If 32 bytes are scanned with no matches
// found, start looking only at every other byte. If 32 more bytes are
// scanned (or skipped), look at every third byte, etc.. When a match
// is found, immediately go back to looking at every byte. This is a
// small loss (~5% performance, ~0.1% density) for compressible data
// due to more bookkeeping, but for non-compressible data (such as
// JPEG) it's a huge win since the compressor quickly "realizes" the
// data is incompressible and doesn't bother looking for matches
// everywhere.
//
// The "skip" variable keeps track of how many bytes there are since
// the last match; dividing it by 32 (ie. right-shifting by five) gives
// the number of bytes to move ahead for each iteration.
skip := 32
nextS := s
candidate := 0
for {
s = nextS
bytesBetweenHashLookups := skip >> 5
nextS = s + bytesBetweenHashLookups
skip += bytesBetweenHashLookups
if nextS > sLimit {
goto emitRemainder
}
candidate = int(table[nextHash&tableMask])
table[nextHash&tableMask] = uint16(s)
nextHash = hash(load32(src, nextS), shift)
if load32(src, s) == load32(src, candidate) {
break
}
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
d += emitLiteral(dst[d:], src[nextEmit:s])
// Call emitCopy, and then see if another emitCopy could be our next
// move. Repeat until we find no match for the input immediately after
// what was consumed by the last emitCopy call.
//
// If we exit this loop normally then we need to call emitLiteral next,
// though we don't yet know how big the literal will be. We handle that
// by proceeding to the next iteration of the main loop. We also can
// exit this loop via goto if we get close to exhausting the input.
for {
// Invariant: we have a 4-byte match at s, and no need to emit any
// literal bytes prior to s.
base := s
// Extend the 4-byte match as long as possible.
//
// This is an inlined version of:
// s = extendMatch(src, candidate+4, s+4)
s += 4
for i := candidate + 4; s < len(src) && src[i] == src[s]; i, s = i+1, s+1 {
}
d += emitCopy(dst[d:], base-candidate, s-base)
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-1 and at s. If
// another emitCopy is not our next move, also calculate nextHash
// at s+1. At least on GOARCH=amd64, these three hash calculations
// are faster as one load64 call (with some shifts) instead of
// three load32 calls.
x := load64(src, s-1)
prevHash := hash(uint32(x>>0), shift)
table[prevHash&tableMask] = uint16(s - 1)
currHash := hash(uint32(x>>8), shift)
candidate = int(table[currHash&tableMask])
table[currHash&tableMask] = uint16(s)
if uint32(x>>8) != load32(src, candidate) {
nextHash = hash(uint32(x>>16), shift)
s++
break
}
}
}
emitRemainder:
if nextEmit < len(src) {
d += emitLiteral(dst[d:], src[nextEmit:])
}
return d
}
Server/vendor/github.com/klauspost/compress/internal/snapref/snappy.go
Generated Vendored
+98
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@@ -0,0 +1,98 @@
// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package snapref implements the Snappy compression format. It aims for very
// high speeds and reasonable compression.
//
// There are actually two Snappy formats: block and stream. They are related,
// but different: trying to decompress block-compressed data as a Snappy stream
// will fail, and vice versa. The block format is the Decode and Encode
// functions and the stream format is the Reader and Writer types.
//
// The block format, the more common case, is used when the complete size (the
// number of bytes) of the original data is known upfront, at the time
// compression starts. The stream format, also known as the framing format, is
// for when that isn't always true.
//
// The canonical, C++ implementation is at https://github.com/google/snappy and
// it only implements the block format.
package snapref
import (
"hash/crc32"
)
/*
Each encoded block begins with the varint-encoded length of the decoded data,
followed by a sequence of chunks. Chunks begin and end on byte boundaries. The
first byte of each chunk is broken into its 2 least and 6 most significant bits
called l and m: l ranges in [0, 4) and m ranges in [0, 64). l is the chunk tag.
Zero means a literal tag. All other values mean a copy tag.
For literal tags:
- If m < 60, the next 1 + m bytes are literal bytes.
- Otherwise, let n be the little-endian unsigned integer denoted by the next
m - 59 bytes. The next 1 + n bytes after that are literal bytes.
For copy tags, length bytes are copied from offset bytes ago, in the style of
Lempel-Ziv compression algorithms. In particular:
- For l == 1, the offset ranges in [0, 1<<11) and the length in [4, 12).
The length is 4 + the low 3 bits of m. The high 3 bits of m form bits 8-10
of the offset. The next byte is bits 0-7 of the offset.
- For l == 2, the offset ranges in [0, 1<<16) and the length in [1, 65).
The length is 1 + m. The offset is the little-endian unsigned integer
denoted by the next 2 bytes.
- For l == 3, this tag is a legacy format that is no longer issued by most
encoders. Nonetheless, the offset ranges in [0, 1<<32) and the length in
[1, 65). The length is 1 + m. The offset is the little-endian unsigned
integer denoted by the next 4 bytes.
*/
const (
tagLiteral = 0x00
tagCopy1 = 0x01
tagCopy2 = 0x02
tagCopy4 = 0x03
)
const (
checksumSize = 4
chunkHeaderSize = 4
magicChunk = "\xff\x06\x00\x00" + magicBody
magicBody = "sNaPpY"
// maxBlockSize is the maximum size of the input to encodeBlock. It is not
// part of the wire format per se, but some parts of the encoder assume
// that an offset fits into a uint16.
//
// Also, for the framing format (Writer type instead of Encode function),
// https://github.com/google/snappy/blob/master/framing_format.txt says
// that "the uncompressed data in a chunk must be no longer than 65536
// bytes".
maxBlockSize = 65536
// maxEncodedLenOfMaxBlockSize equals MaxEncodedLen(maxBlockSize), but is
// hard coded to be a const instead of a variable, so that obufLen can also
// be a const. Their equivalence is confirmed by
// TestMaxEncodedLenOfMaxBlockSize.
maxEncodedLenOfMaxBlockSize = 76490
obufHeaderLen = len(magicChunk) + checksumSize + chunkHeaderSize
obufLen = obufHeaderLen + maxEncodedLenOfMaxBlockSize
)
const (
chunkTypeCompressedData = 0x00
chunkTypeUncompressedData = 0x01
chunkTypePadding = 0xfe
chunkTypeStreamIdentifier = 0xff
)
var crcTable = crc32.MakeTable(crc32.Castagnoli)
// crc implements the checksum specified in section 3 of
// https://github.com/google/snappy/blob/master/framing_format.txt
func crc(b []byte) uint32 {
c := crc32.Update(0, crcTable, b)
return uint32(c>>15|c<<17) + 0xa282ead8
}
Server/vendor/github.com/klauspost/compress/s2/.gitignore
Generated
+15
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@@ -0,0 +1,15 @@
testdata/bench
# These explicitly listed benchmark data files are for an obsolete version of
# snappy_test.go.
testdata/alice29.txt
testdata/asyoulik.txt
testdata/fireworks.jpeg
testdata/geo.protodata
testdata/html
testdata/html_x_4
testdata/kppkn.gtb
testdata/lcet10.txt
testdata/paper-100k.pdf
testdata/plrabn12.txt
testdata/urls.10K
Server/vendor/github.com/klauspost/compress/s2/LICENSE
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+28
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@@ -0,0 +1,28 @@
Copyright (c) 2011 The Snappy-Go Authors. All rights reserved.
Copyright (c) 2019 Klaus Post. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Server/vendor/github.com/klauspost/compress/s2/README.md
Generated Vendored
+1134
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File diff suppressed because it is too large Load Diff
Server/vendor/github.com/klauspost/compress/s2/decode.go
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// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package s2
import (
"encoding/binary"
"errors"
"fmt"
"strconv"
"github.com/klauspost/compress/internal/race"
)
var (
// ErrCorrupt reports that the input is invalid.
ErrCorrupt = errors.New("s2: corrupt input")
// ErrCRC reports that the input failed CRC validation (streams only)
ErrCRC = errors.New("s2: corrupt input, crc mismatch")
// ErrTooLarge reports that the uncompressed length is too large.
ErrTooLarge = errors.New("s2: decoded block is too large")
// ErrUnsupported reports that the input isn't supported.
ErrUnsupported = errors.New("s2: unsupported input")
)
// DecodedLen returns the length of the decoded block.
func DecodedLen(src []byte) (int, error) {
v, _, err := decodedLen(src)
return v, err
}
// decodedLen returns the length of the decoded block and the number of bytes
// that the length header occupied.
func decodedLen(src []byte) (blockLen, headerLen int, err error) {
v, n := binary.Uvarint(src)
if n <= 0 || v > 0xffffffff {
return 0, 0, ErrCorrupt
}
const wordSize = 32 << (^uint(0) >> 32 & 1)
if wordSize == 32 && v > 0x7fffffff {
return 0, 0, ErrTooLarge
}
return int(v), n, nil
}
const (
decodeErrCodeCorrupt = 1
)
// Decode returns the decoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire decoded block.
// Otherwise, a newly allocated slice will be returned.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
func Decode(dst, src []byte) ([]byte, error) {
dLen, s, err := decodedLen(src)
if err != nil {
return nil, err
}
if dLen <= cap(dst) {
dst = dst[:dLen]
} else {
dst = make([]byte, dLen)
}
race.WriteSlice(dst)
race.ReadSlice(src[s:])
if s2Decode(dst, src[s:]) != 0 {
return nil, ErrCorrupt
}
return dst, nil
}
// s2DecodeDict writes the decoding of src to dst. It assumes that the varint-encoded
// length of the decompressed bytes has already been read, and that len(dst)
// equals that length.
//
// It returns 0 on success or a decodeErrCodeXxx error code on failure.
func s2DecodeDict(dst, src []byte, dict *Dict) int {
if dict == nil {
return s2Decode(dst, src)
}
const debug = false
const debugErrs = debug
if debug {
fmt.Println("Starting decode, dst len:", len(dst))
}
var d, s, length int
offset := len(dict.dict) - dict.repeat
// As long as we can read at least 5 bytes...
for s < len(src)-5 {
// Removing bounds checks is SLOWER, when if doing
// in := src[s:s+5]
// Checked on Go 1.18
switch src[s] & 0x03 {
case tagLiteral:
x := uint32(src[s] >> 2)
switch {
case x < 60:
s++
case x == 60:
s += 2
x = uint32(src[s-1])
case x == 61:
in := src[s : s+3]
x = uint32(in[1]) | uint32(in[2])<<8
s += 3
case x == 62:
in := src[s : s+4]
// Load as 32 bit and shift down.
x = uint32(in[0]) | uint32(in[1])<<8 | uint32(in[2])<<16 | uint32(in[3])<<24
x >>= 8
s += 4
case x == 63:
in := src[s : s+5]
x = uint32(in[1]) | uint32(in[2])<<8 | uint32(in[3])<<16 | uint32(in[4])<<24
s += 5
}
length = int(x) + 1
if debug {
fmt.Println("literals, length:", length, "d-after:", d+length)
}
if length > len(dst)-d || length > len(src)-s || (strconv.IntSize == 32 && length <= 0) {
if debugErrs {
fmt.Println("corrupt literal: length:", length, "d-left:", len(dst)-d, "src-left:", len(src)-s)
}
return decodeErrCodeCorrupt
}
copy(dst[d:], src[s:s+length])
d += length
s += length
continue
case tagCopy1:
s += 2
toffset := int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
length = int(src[s-2]) >> 2 & 0x7
if toffset == 0 {
if debug {
fmt.Print("(repeat) ")
}
// keep last offset
switch length {
case 5:
length = int(src[s]) + 4
s += 1
case 6:
in := src[s : s+2]
length = int(uint32(in[0])|(uint32(in[1])<<8)) + (1 << 8)
s += 2
case 7:
in := src[s : s+3]
length = int((uint32(in[2])<<16)|(uint32(in[1])<<8)|uint32(in[0])) + (1 << 16)
s += 3
default: // 0-> 4
}
} else {
offset = toffset
}
length += 4
case tagCopy2:
in := src[s : s+3]
offset = int(uint32(in[1]) | uint32(in[2])<<8)
length = 1 + int(in[0])>>2
s += 3
case tagCopy4:
in := src[s : s+5]
offset = int(uint32(in[1]) | uint32(in[2])<<8 | uint32(in[3])<<16 | uint32(in[4])<<24)
length = 1 + int(in[0])>>2
s += 5
}
if offset <= 0 || length > len(dst)-d {
if debugErrs {
fmt.Println("match error; offset:", offset, "length:", length, "dst-left:", len(dst)-d)
}
return decodeErrCodeCorrupt
}
// copy from dict
if d < offset {
if d > MaxDictSrcOffset {
if debugErrs {
fmt.Println("dict after", MaxDictSrcOffset, "d:", d, "offset:", offset, "length:", length)
}
return decodeErrCodeCorrupt
}
startOff := len(dict.dict) - offset + d
if startOff < 0 || startOff+length > len(dict.dict) {
if debugErrs {
fmt.Printf("offset (%d) + length (%d) bigger than dict (%d)\n", offset, length, len(dict.dict))
}
return decodeErrCodeCorrupt
}
if debug {
fmt.Println("dict copy, length:", length, "offset:", offset, "d-after:", d+length, "dict start offset:", startOff)
}
copy(dst[d:d+length], dict.dict[startOff:])
d += length
continue
}
if debug {
fmt.Println("copy, length:", length, "offset:", offset, "d-after:", d+length)
}
// Copy from an earlier sub-slice of dst to a later sub-slice.
// If no overlap, use the built-in copy:
if offset > length {
copy(dst[d:d+length], dst[d-offset:])
d += length
continue
}
// Unlike the built-in copy function, this byte-by-byte copy always runs
// forwards, even if the slices overlap. Conceptually, this is:
//
// d += forwardCopy(dst[d:d+length], dst[d-offset:])
//
// We align the slices into a and b and show the compiler they are the same size.
// This allows the loop to run without bounds checks.
a := dst[d : d+length]
b := dst[d-offset:]
b = b[:len(a)]
for i := range a {
a[i] = b[i]
}
d += length
}
// Remaining with extra checks...
for s < len(src) {
switch src[s] & 0x03 {
case tagLiteral:
x := uint32(src[s] >> 2)
switch {
case x < 60:
s++
case x == 60:
s += 2
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
if debugErrs {
fmt.Println("src went oob")
}
return decodeErrCodeCorrupt
}
x = uint32(src[s-1])
case x == 61:
s += 3
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
if debugErrs {
fmt.Println("src went oob")
}
return decodeErrCodeCorrupt
}
x = uint32(src[s-2]) | uint32(src[s-1])<<8
case x == 62:
s += 4
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
if debugErrs {
fmt.Println("src went oob")
}
return decodeErrCodeCorrupt
}
x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
case x == 63:
s += 5
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
if debugErrs {
fmt.Println("src went oob")
}
return decodeErrCodeCorrupt
}
x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
}
length = int(x) + 1
if length > len(dst)-d || length > len(src)-s || (strconv.IntSize == 32 && length <= 0) {
if debugErrs {
fmt.Println("corrupt literal: length:", length, "d-left:", len(dst)-d, "src-left:", len(src)-s)
}
return decodeErrCodeCorrupt
}
if debug {
fmt.Println("literals, length:", length, "d-after:", d+length)
}
copy(dst[d:], src[s:s+length])
d += length
s += length
continue
case tagCopy1:
s += 2
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
if debugErrs {
fmt.Println("src went oob")
}
return decodeErrCodeCorrupt
}
length = int(src[s-2]) >> 2 & 0x7
toffset := int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
if toffset == 0 {
if debug {
fmt.Print("(repeat) ")
}
// keep last offset
switch length {
case 5:
s += 1
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
if debugErrs {
fmt.Println("src went oob")
}
return decodeErrCodeCorrupt
}
length = int(uint32(src[s-1])) + 4
case 6:
s += 2
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
if debugErrs {
fmt.Println("src went oob")
}
return decodeErrCodeCorrupt
}
length = int(uint32(src[s-2])|(uint32(src[s-1])<<8)) + (1 << 8)
case 7:
s += 3
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
if debugErrs {
fmt.Println("src went oob")
}
return decodeErrCodeCorrupt
}
length = int(uint32(src[s-3])|(uint32(src[s-2])<<8)|(uint32(src[s-1])<<16)) + (1 << 16)
default: // 0-> 4
}
} else {
offset = toffset
}
length += 4
case tagCopy2:
s += 3
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
if debugErrs {
fmt.Println("src went oob")
}
return decodeErrCodeCorrupt
}
length = 1 + int(src[s-3])>>2
offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
case tagCopy4:
s += 5
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
if debugErrs {
fmt.Println("src went oob")
}
return decodeErrCodeCorrupt
}
length = 1 + int(src[s-5])>>2
offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
}
if offset <= 0 || length > len(dst)-d {
if debugErrs {
fmt.Println("match error; offset:", offset, "length:", length, "dst-left:", len(dst)-d)
}
return decodeErrCodeCorrupt
}
// copy from dict
if d < offset {
if d > MaxDictSrcOffset {
if debugErrs {
fmt.Println("dict after", MaxDictSrcOffset, "d:", d, "offset:", offset, "length:", length)
}
return decodeErrCodeCorrupt
}
rOff := len(dict.dict) - (offset - d)
if debug {
fmt.Println("starting dict entry from dict offset", len(dict.dict)-rOff)
}
if rOff+length > len(dict.dict) {
if debugErrs {
fmt.Println("err: END offset", rOff+length, "bigger than dict", len(dict.dict), "dict offset:", rOff, "length:", length)
}
return decodeErrCodeCorrupt
}
if rOff < 0 {
if debugErrs {
fmt.Println("err: START offset", rOff, "less than 0", len(dict.dict), "dict offset:", rOff, "length:", length)
}
return decodeErrCodeCorrupt
}
copy(dst[d:d+length], dict.dict[rOff:])
d += length
continue
}
if debug {
fmt.Println("copy, length:", length, "offset:", offset, "d-after:", d+length)
}
// Copy from an earlier sub-slice of dst to a later sub-slice.
// If no overlap, use the built-in copy:
if offset > length {
copy(dst[d:d+length], dst[d-offset:])
d += length
continue
}
// Unlike the built-in copy function, this byte-by-byte copy always runs
// forwards, even if the slices overlap. Conceptually, this is:
//
// d += forwardCopy(dst[d:d+length], dst[d-offset:])
//
// We align the slices into a and b and show the compiler they are the same size.
// This allows the loop to run without bounds checks.
a := dst[d : d+length]
b := dst[d-offset:]
b = b[:len(a)]
for i := range a {
a[i] = b[i]
}
d += length
}
if d != len(dst) {
if debugErrs {
fmt.Println("wanted length", len(dst), "got", d)
}
return decodeErrCodeCorrupt
}
return 0
}
Server/vendor/github.com/klauspost/compress/s2/decode_amd64.s
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// Copyright 2016 The Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build !appengine
// +build gc
// +build !noasm
#include "textflag.h"
#define R_TMP0 AX
#define R_TMP1 BX
#define R_LEN CX
#define R_OFF DX
#define R_SRC SI
#define R_DST DI
#define R_DBASE R8
#define R_DLEN R9
#define R_DEND R10
#define R_SBASE R11
#define R_SLEN R12
#define R_SEND R13
#define R_TMP2 R14
#define R_TMP3 R15
// The asm code generally follows the pure Go code in decode_other.go, except
// where marked with a "!!!".
// func decode(dst, src []byte) int
//
// All local variables fit into registers. The non-zero stack size is only to
// spill registers and push args when issuing a CALL. The register allocation:
// - R_TMP0 scratch
// - R_TMP1 scratch
// - R_LEN length or x (shared)
// - R_OFF offset
// - R_SRC &src[s]
// - R_DST &dst[d]
// + R_DBASE dst_base
// + R_DLEN dst_len
// + R_DEND dst_base + dst_len
// + R_SBASE src_base
// + R_SLEN src_len
// + R_SEND src_base + src_len
// - R_TMP2 used by doCopy
// - R_TMP3 used by doCopy
//
// The registers R_DBASE-R_SEND (marked with a "+") are set at the start of the
// function, and after a CALL returns, and are not otherwise modified.
//
// The d variable is implicitly R_DST - R_DBASE, and len(dst)-d is R_DEND - R_DST.
// The s variable is implicitly R_SRC - R_SBASE, and len(src)-s is R_SEND - R_SRC.
TEXT ·s2Decode(SB), NOSPLIT, $48-56
// Initialize R_SRC, R_DST and R_DBASE-R_SEND.
MOVQ dst_base+0(FP), R_DBASE
MOVQ dst_len+8(FP), R_DLEN
MOVQ R_DBASE, R_DST
MOVQ R_DBASE, R_DEND
ADDQ R_DLEN, R_DEND
MOVQ src_base+24(FP), R_SBASE
MOVQ src_len+32(FP), R_SLEN
MOVQ R_SBASE, R_SRC
MOVQ R_SBASE, R_SEND
ADDQ R_SLEN, R_SEND
XORQ R_OFF, R_OFF
loop:
// for s < len(src)
CMPQ R_SRC, R_SEND
JEQ end
// R_LEN = uint32(src[s])
//
// switch src[s] & 0x03
MOVBLZX (R_SRC), R_LEN
MOVL R_LEN, R_TMP1
ANDL $3, R_TMP1
CMPL R_TMP1, $1
JAE tagCopy
// ----------------------------------------
// The code below handles literal tags.
// case tagLiteral:
// x := uint32(src[s] >> 2)
// switch
SHRL $2, R_LEN
CMPL R_LEN, $60
JAE tagLit60Plus
// case x < 60:
// s++
INCQ R_SRC
doLit:
// This is the end of the inner "switch", when we have a literal tag.
//
// We assume that R_LEN == x and x fits in a uint32, where x is the variable
// used in the pure Go decode_other.go code.
// length = int(x) + 1
//
// Unlike the pure Go code, we don't need to check if length <= 0 because
// R_LEN can hold 64 bits, so the increment cannot overflow.
INCQ R_LEN
// Prepare to check if copying length bytes will run past the end of dst or
// src.
//
// R_TMP0 = len(dst) - d
// R_TMP1 = len(src) - s
MOVQ R_DEND, R_TMP0
SUBQ R_DST, R_TMP0
MOVQ R_SEND, R_TMP1
SUBQ R_SRC, R_TMP1
// !!! Try a faster technique for short (16 or fewer bytes) copies.
//
// if length > 16 || len(dst)-d < 16 || len(src)-s < 16 {
// goto callMemmove // Fall back on calling runtime·memmove.
// }
//
// The C++ snappy code calls this TryFastAppend. It also checks len(src)-s
// against 21 instead of 16, because it cannot assume that all of its input
// is contiguous in memory and so it needs to leave enough source bytes to
// read the next tag without refilling buffers, but Go's Decode assumes
// contiguousness (the src argument is a []byte).
CMPQ R_LEN, $16
JGT callMemmove
CMPQ R_TMP0, $16
JLT callMemmove
CMPQ R_TMP1, $16
JLT callMemmove
// !!! Implement the copy from src to dst as a 16-byte load and store.
// (Decode's documentation says that dst and src must not overlap.)
//
// This always copies 16 bytes, instead of only length bytes, but that's
// OK. If the input is a valid Snappy encoding then subsequent iterations
// will fix up the overrun. Otherwise, Decode returns a nil []byte (and a
// non-nil error), so the overrun will be ignored.
//
// Note that on amd64, it is legal and cheap to issue unaligned 8-byte or
// 16-byte loads and stores. This technique probably wouldn't be as
// effective on architectures that are fussier about alignment.
MOVOU 0(R_SRC), X0
MOVOU X0, 0(R_DST)
// d += length
// s += length
ADDQ R_LEN, R_DST
ADDQ R_LEN, R_SRC
JMP loop
callMemmove:
// if length > len(dst)-d || length > len(src)-s { etc }
CMPQ R_LEN, R_TMP0
JGT errCorrupt
CMPQ R_LEN, R_TMP1
JGT errCorrupt
// copy(dst[d:], src[s:s+length])
//
// This means calling runtime·memmove(&dst[d], &src[s], length), so we push
// R_DST, R_SRC and R_LEN as arguments. Coincidentally, we also need to spill those
// three registers to the stack, to save local variables across the CALL.
MOVQ R_DST, 0(SP)
MOVQ R_SRC, 8(SP)
MOVQ R_LEN, 16(SP)
MOVQ R_DST, 24(SP)
MOVQ R_SRC, 32(SP)
MOVQ R_LEN, 40(SP)
MOVQ R_OFF, 48(SP)
CALL runtime·memmove(SB)
// Restore local variables: unspill registers from the stack and
// re-calculate R_DBASE-R_SEND.
MOVQ 24(SP), R_DST
MOVQ 32(SP), R_SRC
MOVQ 40(SP), R_LEN
MOVQ 48(SP), R_OFF
MOVQ dst_base+0(FP), R_DBASE
MOVQ dst_len+8(FP), R_DLEN
MOVQ R_DBASE, R_DEND
ADDQ R_DLEN, R_DEND
MOVQ src_base+24(FP), R_SBASE
MOVQ src_len+32(FP), R_SLEN
MOVQ R_SBASE, R_SEND
ADDQ R_SLEN, R_SEND
// d += length
// s += length
ADDQ R_LEN, R_DST
ADDQ R_LEN, R_SRC
JMP loop
tagLit60Plus:
// !!! This fragment does the
//
// s += x - 58; if uint(s) > uint(len(src)) { etc }
//
// checks. In the asm version, we code it once instead of once per switch case.
ADDQ R_LEN, R_SRC
SUBQ $58, R_SRC
CMPQ R_SRC, R_SEND
JA errCorrupt
// case x == 60:
CMPL R_LEN, $61
JEQ tagLit61
JA tagLit62Plus
// x = uint32(src[s-1])
MOVBLZX -1(R_SRC), R_LEN
JMP doLit
tagLit61:
// case x == 61:
// x = uint32(src[s-2]) | uint32(src[s-1])<<8
MOVWLZX -2(R_SRC), R_LEN
JMP doLit
tagLit62Plus:
CMPL R_LEN, $62
JA tagLit63
// case x == 62:
// x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
// We read one byte, safe to read one back, since we are just reading tag.
// x = binary.LittleEndian.Uint32(src[s-1:]) >> 8
MOVL -4(R_SRC), R_LEN
SHRL $8, R_LEN
JMP doLit
tagLit63:
// case x == 63:
// x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
MOVL -4(R_SRC), R_LEN
JMP doLit
// The code above handles literal tags.
// ----------------------------------------
// The code below handles copy tags.
tagCopy4:
// case tagCopy4:
// s += 5
ADDQ $5, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// length = 1 + int(src[s-5])>>2
SHRQ $2, R_LEN
INCQ R_LEN
// offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
MOVLQZX -4(R_SRC), R_OFF
JMP doCopy
tagCopy2:
// case tagCopy2:
// s += 3
ADDQ $3, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// length = 1 + int(src[s-3])>>2
SHRQ $2, R_LEN
INCQ R_LEN
// offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
MOVWQZX -2(R_SRC), R_OFF
JMP doCopy
tagCopy:
// We have a copy tag. We assume that:
// - R_TMP1 == src[s] & 0x03
// - R_LEN == src[s]
CMPQ R_TMP1, $2
JEQ tagCopy2
JA tagCopy4
// case tagCopy1:
// s += 2
ADDQ $2, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// offset = int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
// length = 4 + int(src[s-2])>>2&0x7
MOVBQZX -1(R_SRC), R_TMP1
MOVQ R_LEN, R_TMP0
SHRQ $2, R_LEN
ANDQ $0xe0, R_TMP0
ANDQ $7, R_LEN
SHLQ $3, R_TMP0
ADDQ $4, R_LEN
ORQ R_TMP1, R_TMP0
// check if repeat code, ZF set by ORQ.
JZ repeatCode
// This is a regular copy, transfer our temporary value to R_OFF (length)
MOVQ R_TMP0, R_OFF
JMP doCopy
// This is a repeat code.
repeatCode:
// If length < 9, reuse last offset, with the length already calculated.
CMPQ R_LEN, $9
JL doCopyRepeat
// Read additional bytes for length.
JE repeatLen1
// Rare, so the extra branch shouldn't hurt too much.
CMPQ R_LEN, $10
JE repeatLen2
JMP repeatLen3
// Read repeat lengths.
repeatLen1:
// s ++
ADDQ $1, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// length = src[s-1] + 8
MOVBQZX -1(R_SRC), R_LEN
ADDL $8, R_LEN
JMP doCopyRepeat
repeatLen2:
// s +=2
ADDQ $2, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// length = uint32(src[s-2]) | (uint32(src[s-1])<<8) + (1 << 8)
MOVWQZX -2(R_SRC), R_LEN
ADDL $260, R_LEN
JMP doCopyRepeat
repeatLen3:
// s +=3
ADDQ $3, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// length = uint32(src[s-3]) | (uint32(src[s-2])<<8) | (uint32(src[s-1])<<16) + (1 << 16)
// Read one byte further back (just part of the tag, shifted out)
MOVL -4(R_SRC), R_LEN
SHRL $8, R_LEN
ADDL $65540, R_LEN
JMP doCopyRepeat
doCopy:
// This is the end of the outer "switch", when we have a copy tag.
//
// We assume that:
// - R_LEN == length && R_LEN > 0
// - R_OFF == offset
// if d < offset { etc }
MOVQ R_DST, R_TMP1
SUBQ R_DBASE, R_TMP1
CMPQ R_TMP1, R_OFF
JLT errCorrupt
// Repeat values can skip the test above, since any offset > 0 will be in dst.
doCopyRepeat:
// if offset <= 0 { etc }
CMPQ R_OFF, $0
JLE errCorrupt
// if length > len(dst)-d { etc }
MOVQ R_DEND, R_TMP1
SUBQ R_DST, R_TMP1
CMPQ R_LEN, R_TMP1
JGT errCorrupt
// forwardCopy(dst[d:d+length], dst[d-offset:]); d += length
//
// Set:
// - R_TMP2 = len(dst)-d
// - R_TMP3 = &dst[d-offset]
MOVQ R_DEND, R_TMP2
SUBQ R_DST, R_TMP2
MOVQ R_DST, R_TMP3
SUBQ R_OFF, R_TMP3
// !!! Try a faster technique for short (16 or fewer bytes) forward copies.
//
// First, try using two 8-byte load/stores, similar to the doLit technique
// above. Even if dst[d:d+length] and dst[d-offset:] can overlap, this is
// still OK if offset >= 8. Note that this has to be two 8-byte load/stores
// and not one 16-byte load/store, and the first store has to be before the
// second load, due to the overlap if offset is in the range [8, 16).
//
// if length > 16 || offset < 8 || len(dst)-d < 16 {
// goto slowForwardCopy
// }
// copy 16 bytes
// d += length
CMPQ R_LEN, $16
JGT slowForwardCopy
CMPQ R_OFF, $8
JLT slowForwardCopy
CMPQ R_TMP2, $16
JLT slowForwardCopy
MOVQ 0(R_TMP3), R_TMP0
MOVQ R_TMP0, 0(R_DST)
MOVQ 8(R_TMP3), R_TMP1
MOVQ R_TMP1, 8(R_DST)
ADDQ R_LEN, R_DST
JMP loop
slowForwardCopy:
// !!! If the forward copy is longer than 16 bytes, or if offset < 8, we
// can still try 8-byte load stores, provided we can overrun up to 10 extra
// bytes. As above, the overrun will be fixed up by subsequent iterations
// of the outermost loop.
//
// The C++ snappy code calls this technique IncrementalCopyFastPath. Its
// commentary says:
//
// ----
//
// The main part of this loop is a simple copy of eight bytes at a time
// until we've copied (at least) the requested amount of bytes. However,
// if d and d-offset are less than eight bytes apart (indicating a
// repeating pattern of length < 8), we first need to expand the pattern in
// order to get the correct results. For instance, if the buffer looks like
// this, with the eight-byte <d-offset> and <d> patterns marked as
// intervals:
//
// abxxxxxxxxxxxx
// [------] d-offset
// [------] d
//
// a single eight-byte copy from <d-offset> to <d> will repeat the pattern
// once, after which we can move <d> two bytes without moving <d-offset>:
//
// ababxxxxxxxxxx
// [------] d-offset
// [------] d
//
// and repeat the exercise until the two no longer overlap.
//
// This allows us to do very well in the special case of one single byte
// repeated many times, without taking a big hit for more general cases.
//
// The worst case of extra writing past the end of the match occurs when
// offset == 1 and length == 1; the last copy will read from byte positions
// [0..7] and write to [4..11], whereas it was only supposed to write to
// position 1. Thus, ten excess bytes.
//
// ----
//
// That "10 byte overrun" worst case is confirmed by Go's
// TestSlowForwardCopyOverrun, which also tests the fixUpSlowForwardCopy
// and finishSlowForwardCopy algorithm.
//
// if length > len(dst)-d-10 {
// goto verySlowForwardCopy
// }
SUBQ $10, R_TMP2
CMPQ R_LEN, R_TMP2
JGT verySlowForwardCopy
// We want to keep the offset, so we use R_TMP2 from here.
MOVQ R_OFF, R_TMP2
makeOffsetAtLeast8:
// !!! As above, expand the pattern so that offset >= 8 and we can use
// 8-byte load/stores.
//
// for offset < 8 {
// copy 8 bytes from dst[d-offset:] to dst[d:]
// length -= offset
// d += offset
// offset += offset
// // The two previous lines together means that d-offset, and therefore
// // R_TMP3, is unchanged.
// }
CMPQ R_TMP2, $8
JGE fixUpSlowForwardCopy
MOVQ (R_TMP3), R_TMP1
MOVQ R_TMP1, (R_DST)
SUBQ R_TMP2, R_LEN
ADDQ R_TMP2, R_DST
ADDQ R_TMP2, R_TMP2
JMP makeOffsetAtLeast8
fixUpSlowForwardCopy:
// !!! Add length (which might be negative now) to d (implied by R_DST being
// &dst[d]) so that d ends up at the right place when we jump back to the
// top of the loop. Before we do that, though, we save R_DST to R_TMP0 so that, if
// length is positive, copying the remaining length bytes will write to the
// right place.
MOVQ R_DST, R_TMP0
ADDQ R_LEN, R_DST
finishSlowForwardCopy:
// !!! Repeat 8-byte load/stores until length <= 0. Ending with a negative
// length means that we overrun, but as above, that will be fixed up by
// subsequent iterations of the outermost loop.
CMPQ R_LEN, $0
JLE loop
MOVQ (R_TMP3), R_TMP1
MOVQ R_TMP1, (R_TMP0)
ADDQ $8, R_TMP3
ADDQ $8, R_TMP0
SUBQ $8, R_LEN
JMP finishSlowForwardCopy
verySlowForwardCopy:
// verySlowForwardCopy is a simple implementation of forward copy. In C
// parlance, this is a do/while loop instead of a while loop, since we know
// that length > 0. In Go syntax:
//
// for {
// dst[d] = dst[d - offset]
// d++
// length--
// if length == 0 {
// break
// }
// }
MOVB (R_TMP3), R_TMP1
MOVB R_TMP1, (R_DST)
INCQ R_TMP3
INCQ R_DST
DECQ R_LEN
JNZ verySlowForwardCopy
JMP loop
// The code above handles copy tags.
// ----------------------------------------
end:
// This is the end of the "for s < len(src)".
//
// if d != len(dst) { etc }
CMPQ R_DST, R_DEND
JNE errCorrupt
// return 0
MOVQ $0, ret+48(FP)
RET
errCorrupt:
// return decodeErrCodeCorrupt
MOVQ $1, ret+48(FP)
RET
Server/vendor/github.com/klauspost/compress/s2/decode_arm64.s
Generated Vendored
+574
View File
@@ -0,0 +1,574 @@
// Copyright 2020 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build !appengine
// +build gc
// +build !noasm
#include "textflag.h"
#define R_TMP0 R2
#define R_TMP1 R3
#define R_LEN R4
#define R_OFF R5
#define R_SRC R6
#define R_DST R7
#define R_DBASE R8
#define R_DLEN R9
#define R_DEND R10
#define R_SBASE R11
#define R_SLEN R12
#define R_SEND R13
#define R_TMP2 R14
#define R_TMP3 R15
// TEST_SRC will check if R_SRC is <= SRC_END
#define TEST_SRC() \
CMP R_SEND, R_SRC \
BGT errCorrupt
// MOVD R_SRC, R_TMP1
// SUB R_SBASE, R_TMP1, R_TMP1
// CMP R_SLEN, R_TMP1
// BGT errCorrupt
// The asm code generally follows the pure Go code in decode_other.go, except
// where marked with a "!!!".
// func decode(dst, src []byte) int
//
// All local variables fit into registers. The non-zero stack size is only to
// spill registers and push args when issuing a CALL. The register allocation:
// - R_TMP0 scratch
// - R_TMP1 scratch
// - R_LEN length or x
// - R_OFF offset
// - R_SRC &src[s]
// - R_DST &dst[d]
// + R_DBASE dst_base
// + R_DLEN dst_len
// + R_DEND dst_base + dst_len
// + R_SBASE src_base
// + R_SLEN src_len
// + R_SEND src_base + src_len
// - R_TMP2 used by doCopy
// - R_TMP3 used by doCopy
//
// The registers R_DBASE-R_SEND (marked with a "+") are set at the start of the
// function, and after a CALL returns, and are not otherwise modified.
//
// The d variable is implicitly R_DST - R_DBASE, and len(dst)-d is R_DEND - R_DST.
// The s variable is implicitly R_SRC - R_SBASE, and len(src)-s is R_SEND - R_SRC.
TEXT ·s2Decode(SB), NOSPLIT, $56-56
// Initialize R_SRC, R_DST and R_DBASE-R_SEND.
MOVD dst_base+0(FP), R_DBASE
MOVD dst_len+8(FP), R_DLEN
MOVD R_DBASE, R_DST
MOVD R_DBASE, R_DEND
ADD R_DLEN, R_DEND, R_DEND
MOVD src_base+24(FP), R_SBASE
MOVD src_len+32(FP), R_SLEN
MOVD R_SBASE, R_SRC
MOVD R_SBASE, R_SEND
ADD R_SLEN, R_SEND, R_SEND
MOVD $0, R_OFF
loop:
// for s < len(src)
CMP R_SEND, R_SRC
BEQ end
// R_LEN = uint32(src[s])
//
// switch src[s] & 0x03
MOVBU (R_SRC), R_LEN
MOVW R_LEN, R_TMP1
ANDW $3, R_TMP1
MOVW $1, R1
CMPW R1, R_TMP1
BGE tagCopy
// ----------------------------------------
// The code below handles literal tags.
// case tagLiteral:
// x := uint32(src[s] >> 2)
// switch
MOVW $60, R1
LSRW $2, R_LEN, R_LEN
CMPW R_LEN, R1
BLS tagLit60Plus
// case x < 60:
// s++
ADD $1, R_SRC, R_SRC
doLit:
// This is the end of the inner "switch", when we have a literal tag.
//
// We assume that R_LEN == x and x fits in a uint32, where x is the variable
// used in the pure Go decode_other.go code.
// length = int(x) + 1
//
// Unlike the pure Go code, we don't need to check if length <= 0 because
// R_LEN can hold 64 bits, so the increment cannot overflow.
ADD $1, R_LEN, R_LEN
// Prepare to check if copying length bytes will run past the end of dst or
// src.
//
// R_TMP0 = len(dst) - d
// R_TMP1 = len(src) - s
MOVD R_DEND, R_TMP0
SUB R_DST, R_TMP0, R_TMP0
MOVD R_SEND, R_TMP1
SUB R_SRC, R_TMP1, R_TMP1
// !!! Try a faster technique for short (16 or fewer bytes) copies.
//
// if length > 16 || len(dst)-d < 16 || len(src)-s < 16 {
// goto callMemmove // Fall back on calling runtime·memmove.
// }
//
// The C++ snappy code calls this TryFastAppend. It also checks len(src)-s
// against 21 instead of 16, because it cannot assume that all of its input
// is contiguous in memory and so it needs to leave enough source bytes to
// read the next tag without refilling buffers, but Go's Decode assumes
// contiguousness (the src argument is a []byte).
CMP $16, R_LEN
BGT callMemmove
CMP $16, R_TMP0
BLT callMemmove
CMP $16, R_TMP1
BLT callMemmove
// !!! Implement the copy from src to dst as a 16-byte load and store.
// (Decode's documentation says that dst and src must not overlap.)
//
// This always copies 16 bytes, instead of only length bytes, but that's
// OK. If the input is a valid Snappy encoding then subsequent iterations
// will fix up the overrun. Otherwise, Decode returns a nil []byte (and a
// non-nil error), so the overrun will be ignored.
//
// Note that on arm64, it is legal and cheap to issue unaligned 8-byte or
// 16-byte loads and stores. This technique probably wouldn't be as
// effective on architectures that are fussier about alignment.
LDP 0(R_SRC), (R_TMP2, R_TMP3)
STP (R_TMP2, R_TMP3), 0(R_DST)
// d += length
// s += length
ADD R_LEN, R_DST, R_DST
ADD R_LEN, R_SRC, R_SRC
B loop
callMemmove:
// if length > len(dst)-d || length > len(src)-s { etc }
CMP R_TMP0, R_LEN
BGT errCorrupt
CMP R_TMP1, R_LEN
BGT errCorrupt
// copy(dst[d:], src[s:s+length])
//
// This means calling runtime·memmove(&dst[d], &src[s], length), so we push
// R_DST, R_SRC and R_LEN as arguments. Coincidentally, we also need to spill those
// three registers to the stack, to save local variables across the CALL.
MOVD R_DST, 8(RSP)
MOVD R_SRC, 16(RSP)
MOVD R_LEN, 24(RSP)
MOVD R_DST, 32(RSP)
MOVD R_SRC, 40(RSP)
MOVD R_LEN, 48(RSP)
MOVD R_OFF, 56(RSP)
CALL runtime·memmove(SB)
// Restore local variables: unspill registers from the stack and
// re-calculate R_DBASE-R_SEND.
MOVD 32(RSP), R_DST
MOVD 40(RSP), R_SRC
MOVD 48(RSP), R_LEN
MOVD 56(RSP), R_OFF
MOVD dst_base+0(FP), R_DBASE
MOVD dst_len+8(FP), R_DLEN
MOVD R_DBASE, R_DEND
ADD R_DLEN, R_DEND, R_DEND
MOVD src_base+24(FP), R_SBASE
MOVD src_len+32(FP), R_SLEN
MOVD R_SBASE, R_SEND
ADD R_SLEN, R_SEND, R_SEND
// d += length
// s += length
ADD R_LEN, R_DST, R_DST
ADD R_LEN, R_SRC, R_SRC
B loop
tagLit60Plus:
// !!! This fragment does the
//
// s += x - 58; if uint(s) > uint(len(src)) { etc }
//
// checks. In the asm version, we code it once instead of once per switch case.
ADD R_LEN, R_SRC, R_SRC
SUB $58, R_SRC, R_SRC
TEST_SRC()
// case x == 60:
MOVW $61, R1
CMPW R1, R_LEN
BEQ tagLit61
BGT tagLit62Plus
// x = uint32(src[s-1])
MOVBU -1(R_SRC), R_LEN
B doLit
tagLit61:
// case x == 61:
// x = uint32(src[s-2]) | uint32(src[s-1])<<8
MOVHU -2(R_SRC), R_LEN
B doLit
tagLit62Plus:
CMPW $62, R_LEN
BHI tagLit63
// case x == 62:
// x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
MOVHU -3(R_SRC), R_LEN
MOVBU -1(R_SRC), R_TMP1
ORR R_TMP1<<16, R_LEN
B doLit
tagLit63:
// case x == 63:
// x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
MOVWU -4(R_SRC), R_LEN
B doLit
// The code above handles literal tags.
// ----------------------------------------
// The code below handles copy tags.
tagCopy4:
// case tagCopy4:
// s += 5
ADD $5, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
MOVD R_SRC, R_TMP1
SUB R_SBASE, R_TMP1, R_TMP1
CMP R_SLEN, R_TMP1
BGT errCorrupt
// length = 1 + int(src[s-5])>>2
MOVD $1, R1
ADD R_LEN>>2, R1, R_LEN
// offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
MOVWU -4(R_SRC), R_OFF
B doCopy
tagCopy2:
// case tagCopy2:
// s += 3
ADD $3, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
TEST_SRC()
// length = 1 + int(src[s-3])>>2
MOVD $1, R1
ADD R_LEN>>2, R1, R_LEN
// offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
MOVHU -2(R_SRC), R_OFF
B doCopy
tagCopy:
// We have a copy tag. We assume that:
// - R_TMP1 == src[s] & 0x03
// - R_LEN == src[s]
CMP $2, R_TMP1
BEQ tagCopy2
BGT tagCopy4
// case tagCopy1:
// s += 2
ADD $2, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
TEST_SRC()
// offset = int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
// Calculate offset in R_TMP0 in case it is a repeat.
MOVD R_LEN, R_TMP0
AND $0xe0, R_TMP0
MOVBU -1(R_SRC), R_TMP1
ORR R_TMP0<<3, R_TMP1, R_TMP0
// length = 4 + int(src[s-2])>>2&0x7
MOVD $7, R1
AND R_LEN>>2, R1, R_LEN
ADD $4, R_LEN, R_LEN
// check if repeat code with offset 0.
CMP $0, R_TMP0
BEQ repeatCode
// This is a regular copy, transfer our temporary value to R_OFF (offset)
MOVD R_TMP0, R_OFF
B doCopy
// This is a repeat code.
repeatCode:
// If length < 9, reuse last offset, with the length already calculated.
CMP $9, R_LEN
BLT doCopyRepeat
BEQ repeatLen1
CMP $10, R_LEN
BEQ repeatLen2
repeatLen3:
// s +=3
ADD $3, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
TEST_SRC()
// length = uint32(src[s-3]) | (uint32(src[s-2])<<8) | (uint32(src[s-1])<<16) + 65540
MOVBU -1(R_SRC), R_TMP0
MOVHU -3(R_SRC), R_LEN
ORR R_TMP0<<16, R_LEN, R_LEN
ADD $65540, R_LEN, R_LEN
B doCopyRepeat
repeatLen2:
// s +=2
ADD $2, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
TEST_SRC()
// length = uint32(src[s-2]) | (uint32(src[s-1])<<8) + 260
MOVHU -2(R_SRC), R_LEN
ADD $260, R_LEN, R_LEN
B doCopyRepeat
repeatLen1:
// s +=1
ADD $1, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
TEST_SRC()
// length = src[s-1] + 8
MOVBU -1(R_SRC), R_LEN
ADD $8, R_LEN, R_LEN
B doCopyRepeat
doCopy:
// This is the end of the outer "switch", when we have a copy tag.
//
// We assume that:
// - R_LEN == length && R_LEN > 0
// - R_OFF == offset
// if d < offset { etc }
MOVD R_DST, R_TMP1
SUB R_DBASE, R_TMP1, R_TMP1
CMP R_OFF, R_TMP1
BLT errCorrupt
// Repeat values can skip the test above, since any offset > 0 will be in dst.
doCopyRepeat:
// if offset <= 0 { etc }
CMP $0, R_OFF
BLE errCorrupt
// if length > len(dst)-d { etc }
MOVD R_DEND, R_TMP1
SUB R_DST, R_TMP1, R_TMP1
CMP R_TMP1, R_LEN
BGT errCorrupt
// forwardCopy(dst[d:d+length], dst[d-offset:]); d += length
//
// Set:
// - R_TMP2 = len(dst)-d
// - R_TMP3 = &dst[d-offset]
MOVD R_DEND, R_TMP2
SUB R_DST, R_TMP2, R_TMP2
MOVD R_DST, R_TMP3
SUB R_OFF, R_TMP3, R_TMP3
// !!! Try a faster technique for short (16 or fewer bytes) forward copies.
//
// First, try using two 8-byte load/stores, similar to the doLit technique
// above. Even if dst[d:d+length] and dst[d-offset:] can overlap, this is
// still OK if offset >= 8. Note that this has to be two 8-byte load/stores
// and not one 16-byte load/store, and the first store has to be before the
// second load, due to the overlap if offset is in the range [8, 16).
//
// if length > 16 || offset < 8 || len(dst)-d < 16 {
// goto slowForwardCopy
// }
// copy 16 bytes
// d += length
CMP $16, R_LEN
BGT slowForwardCopy
CMP $8, R_OFF
BLT slowForwardCopy
CMP $16, R_TMP2
BLT slowForwardCopy
MOVD 0(R_TMP3), R_TMP0
MOVD R_TMP0, 0(R_DST)
MOVD 8(R_TMP3), R_TMP1
MOVD R_TMP1, 8(R_DST)
ADD R_LEN, R_DST, R_DST
B loop
slowForwardCopy:
// !!! If the forward copy is longer than 16 bytes, or if offset < 8, we
// can still try 8-byte load stores, provided we can overrun up to 10 extra
// bytes. As above, the overrun will be fixed up by subsequent iterations
// of the outermost loop.
//
// The C++ snappy code calls this technique IncrementalCopyFastPath. Its
// commentary says:
//
// ----
//
// The main part of this loop is a simple copy of eight bytes at a time
// until we've copied (at least) the requested amount of bytes. However,
// if d and d-offset are less than eight bytes apart (indicating a
// repeating pattern of length < 8), we first need to expand the pattern in
// order to get the correct results. For instance, if the buffer looks like
// this, with the eight-byte <d-offset> and <d> patterns marked as
// intervals:
//
// abxxxxxxxxxxxx
// [------] d-offset
// [------] d
//
// a single eight-byte copy from <d-offset> to <d> will repeat the pattern
// once, after which we can move <d> two bytes without moving <d-offset>:
//
// ababxxxxxxxxxx
// [------] d-offset
// [------] d
//
// and repeat the exercise until the two no longer overlap.
//
// This allows us to do very well in the special case of one single byte
// repeated many times, without taking a big hit for more general cases.
//
// The worst case of extra writing past the end of the match occurs when
// offset == 1 and length == 1; the last copy will read from byte positions
// [0..7] and write to [4..11], whereas it was only supposed to write to
// position 1. Thus, ten excess bytes.
//
// ----
//
// That "10 byte overrun" worst case is confirmed by Go's
// TestSlowForwardCopyOverrun, which also tests the fixUpSlowForwardCopy
// and finishSlowForwardCopy algorithm.
//
// if length > len(dst)-d-10 {
// goto verySlowForwardCopy
// }
SUB $10, R_TMP2, R_TMP2
CMP R_TMP2, R_LEN
BGT verySlowForwardCopy
// We want to keep the offset, so we use R_TMP2 from here.
MOVD R_OFF, R_TMP2
makeOffsetAtLeast8:
// !!! As above, expand the pattern so that offset >= 8 and we can use
// 8-byte load/stores.
//
// for offset < 8 {
// copy 8 bytes from dst[d-offset:] to dst[d:]
// length -= offset
// d += offset
// offset += offset
// // The two previous lines together means that d-offset, and therefore
// // R_TMP3, is unchanged.
// }
CMP $8, R_TMP2
BGE fixUpSlowForwardCopy
MOVD (R_TMP3), R_TMP1
MOVD R_TMP1, (R_DST)
SUB R_TMP2, R_LEN, R_LEN
ADD R_TMP2, R_DST, R_DST
ADD R_TMP2, R_TMP2, R_TMP2
B makeOffsetAtLeast8
fixUpSlowForwardCopy:
// !!! Add length (which might be negative now) to d (implied by R_DST being
// &dst[d]) so that d ends up at the right place when we jump back to the
// top of the loop. Before we do that, though, we save R_DST to R_TMP0 so that, if
// length is positive, copying the remaining length bytes will write to the
// right place.
MOVD R_DST, R_TMP0
ADD R_LEN, R_DST, R_DST
finishSlowForwardCopy:
// !!! Repeat 8-byte load/stores until length <= 0. Ending with a negative
// length means that we overrun, but as above, that will be fixed up by
// subsequent iterations of the outermost loop.
MOVD $0, R1
CMP R1, R_LEN
BLE loop
MOVD (R_TMP3), R_TMP1
MOVD R_TMP1, (R_TMP0)
ADD $8, R_TMP3, R_TMP3
ADD $8, R_TMP0, R_TMP0
SUB $8, R_LEN, R_LEN
B finishSlowForwardCopy
verySlowForwardCopy:
// verySlowForwardCopy is a simple implementation of forward copy. In C
// parlance, this is a do/while loop instead of a while loop, since we know
// that length > 0. In Go syntax:
//
// for {
// dst[d] = dst[d - offset]
// d++
// length--
// if length == 0 {
// break
// }
// }
MOVB (R_TMP3), R_TMP1
MOVB R_TMP1, (R_DST)
ADD $1, R_TMP3, R_TMP3
ADD $1, R_DST, R_DST
SUB $1, R_LEN, R_LEN
CBNZ R_LEN, verySlowForwardCopy
B loop
// The code above handles copy tags.
// ----------------------------------------
end:
// This is the end of the "for s < len(src)".
//
// if d != len(dst) { etc }
CMP R_DEND, R_DST
BNE errCorrupt
// return 0
MOVD $0, ret+48(FP)
RET
errCorrupt:
// return decodeErrCodeCorrupt
MOVD $1, R_TMP0
MOVD R_TMP0, ret+48(FP)
RET
Server/vendor/github.com/klauspost/compress/s2/decode_asm.go
Generated Vendored
+17
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@@ -0,0 +1,17 @@
// Copyright 2016 The Snappy-Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build (amd64 || arm64) && !appengine && gc && !noasm
// +build amd64 arm64
// +build !appengine
// +build gc
// +build !noasm
package s2
// decode has the same semantics as in decode_other.go.
//
//go:noescape
func s2Decode(dst, src []byte) int
Server/vendor/github.com/klauspost/compress/s2/decode_other.go
Generated Vendored
+287
View File
@@ -0,0 +1,287 @@
// Copyright 2016 The Snappy-Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build (!amd64 && !arm64) || appengine || !gc || noasm
package s2
import (
"fmt"
"strconv"
"github.com/klauspost/compress/internal/le"
)
// decode writes the decoding of src to dst. It assumes that the varint-encoded
// length of the decompressed bytes has already been read, and that len(dst)
// equals that length.
//
// It returns 0 on success or a decodeErrCodeXxx error code on failure.
func s2Decode(dst, src []byte) int {
const debug = false
if debug {
fmt.Println("Starting decode, dst len:", len(dst))
}
var d, s, length int
offset := 0
// As long as we can read at least 5 bytes...
for s < len(src)-5 {
// Removing bounds checks is SLOWER, when if doing
// in := src[s:s+5]
// Checked on Go 1.18
switch src[s] & 0x03 {
case tagLiteral:
x := uint32(src[s] >> 2)
switch {
case x < 60:
s++
case x == 60:
x = uint32(src[s+1])
s += 2
case x == 61:
x = uint32(le.Load16(src, s+1))
s += 3
case x == 62:
// Load as 32 bit and shift down.
x = le.Load32(src, s)
x >>= 8
s += 4
case x == 63:
x = le.Load32(src, s+1)
s += 5
}
length = int(x) + 1
if length > len(dst)-d || length > len(src)-s || (strconv.IntSize == 32 && length <= 0) {
if debug {
fmt.Println("corrupt: lit size", length)
}
return decodeErrCodeCorrupt
}
if debug {
fmt.Println("literals, length:", length, "d-after:", d+length)
}
copy(dst[d:], src[s:s+length])
d += length
s += length
continue
case tagCopy1:
s += 2
toffset := int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
length = int(src[s-2]) >> 2 & 0x7
if toffset == 0 {
if debug {
fmt.Print("(repeat) ")
}
// keep last offset
switch length {
case 5:
length = int(src[s]) + 4
s += 1
case 6:
length = int(le.Load16(src, s)) + 1<<8
s += 2
case 7:
in := src[s : s+3]
length = int((uint32(in[2])<<16)|(uint32(in[1])<<8)|uint32(in[0])) + (1 << 16)
s += 3
default: // 0-> 4
}
} else {
offset = toffset
}
length += 4
case tagCopy2:
offset = int(le.Load16(src, s+1))
length = 1 + int(src[s])>>2
s += 3
case tagCopy4:
offset = int(le.Load32(src, s+1))
length = 1 + int(src[s])>>2
s += 5
}
if offset <= 0 || d < offset || length > len(dst)-d {
if debug {
fmt.Println("corrupt: match, length", length, "offset:", offset, "dst avail:", len(dst)-d, "dst pos:", d)
}
return decodeErrCodeCorrupt
}
if debug {
fmt.Println("copy, length:", length, "offset:", offset, "d-after:", d+length)
}
// Copy from an earlier sub-slice of dst to a later sub-slice.
// If no overlap, use the built-in copy:
if offset > length {
copy(dst[d:d+length], dst[d-offset:])
d += length
continue
}
// Unlike the built-in copy function, this byte-by-byte copy always runs
// forwards, even if the slices overlap. Conceptually, this is:
//
// d += forwardCopy(dst[d:d+length], dst[d-offset:])
//
// We align the slices into a and b and show the compiler they are the same size.
// This allows the loop to run without bounds checks.
a := dst[d : d+length]
b := dst[d-offset:]
b = b[:len(a)]
for i := range a {
a[i] = b[i]
}
d += length
}
// Remaining with extra checks...
for s < len(src) {
switch src[s] & 0x03 {
case tagLiteral:
x := uint32(src[s] >> 2)
switch {
case x < 60:
s++
case x == 60:
s += 2
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
x = uint32(src[s-1])
case x == 61:
s += 3
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
x = uint32(src[s-2]) | uint32(src[s-1])<<8
case x == 62:
s += 4
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
case x == 63:
s += 5
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
}
length = int(x) + 1
if length > len(dst)-d || length > len(src)-s || (strconv.IntSize == 32 && length <= 0) {
if debug {
fmt.Println("corrupt: lit size", length)
}
return decodeErrCodeCorrupt
}
if debug {
fmt.Println("literals, length:", length, "d-after:", d+length)
}
copy(dst[d:], src[s:s+length])
d += length
s += length
continue
case tagCopy1:
s += 2
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = int(src[s-2]) >> 2 & 0x7
toffset := int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
if toffset == 0 {
if debug {
fmt.Print("(repeat) ")
}
// keep last offset
switch length {
case 5:
s += 1
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = int(uint32(src[s-1])) + 4
case 6:
s += 2
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = int(uint32(src[s-2])|(uint32(src[s-1])<<8)) + (1 << 8)
case 7:
s += 3
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = int(uint32(src[s-3])|(uint32(src[s-2])<<8)|(uint32(src[s-1])<<16)) + (1 << 16)
default: // 0-> 4
}
} else {
offset = toffset
}
length += 4
case tagCopy2:
s += 3
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = 1 + int(src[s-3])>>2
offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
case tagCopy4:
s += 5
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = 1 + int(src[s-5])>>2
offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
}
if offset <= 0 || d < offset || length > len(dst)-d {
if debug {
fmt.Println("corrupt: match, length", length, "offset:", offset, "dst avail:", len(dst)-d, "dst pos:", d)
}
return decodeErrCodeCorrupt
}
if debug {
fmt.Println("copy, length:", length, "offset:", offset, "d-after:", d+length)
}
// Copy from an earlier sub-slice of dst to a later sub-slice.
// If no overlap, use the built-in copy:
if offset > length {
copy(dst[d:d+length], dst[d-offset:])
d += length
continue
}
// Unlike the built-in copy function, this byte-by-byte copy always runs
// forwards, even if the slices overlap. Conceptually, this is:
//
// d += forwardCopy(dst[d:d+length], dst[d-offset:])
//
// We align the slices into a and b and show the compiler they are the same size.
// This allows the loop to run without bounds checks.
a := dst[d : d+length]
b := dst[d-offset:]
b = b[:len(a)]
for i := range a {
a[i] = b[i]
}
d += length
}
if d != len(dst) {
return decodeErrCodeCorrupt
}
return 0
}
Server/vendor/github.com/klauspost/compress/s2/dict.go
Generated Vendored
+350
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@@ -0,0 +1,350 @@
// Copyright (c) 2022+ Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package s2
import (
"bytes"
"encoding/binary"
"sync"
)
const (
// MinDictSize is the minimum dictionary size when repeat has been read.
MinDictSize = 16
// MaxDictSize is the maximum dictionary size when repeat has been read.
MaxDictSize = 65536
// MaxDictSrcOffset is the maximum offset where a dictionary entry can start.
MaxDictSrcOffset = 65535
)
// Dict contains a dictionary that can be used for encoding and decoding s2
type Dict struct {
dict []byte
repeat int // Repeat as index of dict
fast, better, best sync.Once
fastTable *[1 << 14]uint16
betterTableShort *[1 << 14]uint16
betterTableLong *[1 << 17]uint16
bestTableShort *[1 << 16]uint32
bestTableLong *[1 << 19]uint32
}
// NewDict will read a dictionary.
// It will return nil if the dictionary is invalid.
func NewDict(dict []byte) *Dict {
if len(dict) == 0 {
return nil
}
var d Dict
// Repeat is the first value of the dict
r, n := binary.Uvarint(dict)
if n <= 0 {
return nil
}
dict = dict[n:]
d.dict = dict
if cap(d.dict) < len(d.dict)+16 {
d.dict = append(make([]byte, 0, len(d.dict)+16), d.dict...)
}
if len(dict) < MinDictSize || len(dict) > MaxDictSize {
return nil
}
d.repeat = int(r)
if d.repeat > len(dict) {
return nil
}
return &d
}
// Bytes will return a serialized version of the dictionary.
// The output can be sent to NewDict.
func (d *Dict) Bytes() []byte {
dst := make([]byte, binary.MaxVarintLen16+len(d.dict))
return append(dst[:binary.PutUvarint(dst, uint64(d.repeat))], d.dict...)
}
// MakeDict will create a dictionary.
// 'data' must be at least MinDictSize.
// If data is longer than MaxDictSize only the last MaxDictSize bytes will be used.
// If searchStart is set the start repeat value will be set to the last
// match of this content.
// If no matches are found, it will attempt to find shorter matches.
// This content should match the typical start of a block.
// If at least 4 bytes cannot be matched, repeat is set to start of block.
func MakeDict(data []byte, searchStart []byte) *Dict {
if len(data) == 0 {
return nil
}
if len(data) > MaxDictSize {
data = data[len(data)-MaxDictSize:]
}
var d Dict
dict := data
d.dict = dict
if cap(d.dict) < len(d.dict)+16 {
d.dict = append(make([]byte, 0, len(d.dict)+16), d.dict...)
}
if len(dict) < MinDictSize {
return nil
}
// Find the longest match possible, last entry if multiple.
for s := len(searchStart); s > 4; s-- {
if idx := bytes.LastIndex(data, searchStart[:s]); idx >= 0 && idx <= len(data)-8 {
d.repeat = idx
break
}
}
return &d
}
// MakeDictManual will create a dictionary.
// 'data' must be at least MinDictSize and less than or equal to MaxDictSize.
// A manual first repeat index into data must be provided.
// It must be less than len(data)-8.
func MakeDictManual(data []byte, firstIdx uint16) *Dict {
if len(data) < MinDictSize || int(firstIdx) >= len(data)-8 || len(data) > MaxDictSize {
return nil
}
var d Dict
dict := data
d.dict = dict
if cap(d.dict) < len(d.dict)+16 {
d.dict = append(make([]byte, 0, len(d.dict)+16), d.dict...)
}
d.repeat = int(firstIdx)
return &d
}
// Encode returns the encoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire encoded block.
// Otherwise, a newly allocated slice will be returned.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func (d *Dict) Encode(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if cap(dst) < n {
dst = make([]byte, n)
} else {
dst = dst[:n]
}
// The block starts with the varint-encoded length of the decompressed bytes.
dstP := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:dstP]
}
if len(src) < minNonLiteralBlockSize {
dstP += emitLiteral(dst[dstP:], src)
return dst[:dstP]
}
n := encodeBlockDictGo(dst[dstP:], src, d)
if n > 0 {
dstP += n
return dst[:dstP]
}
// Not compressible
dstP += emitLiteral(dst[dstP:], src)
return dst[:dstP]
}
// EncodeBetter returns the encoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire encoded block.
// Otherwise, a newly allocated slice will be returned.
//
// EncodeBetter compresses better than Encode but typically with a
// 10-40% speed decrease on both compression and decompression.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func (d *Dict) EncodeBetter(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if len(dst) < n {
dst = make([]byte, n)
}
// The block starts with the varint-encoded length of the decompressed bytes.
dstP := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:dstP]
}
if len(src) < minNonLiteralBlockSize {
dstP += emitLiteral(dst[dstP:], src)
return dst[:dstP]
}
n := encodeBlockBetterDict(dst[dstP:], src, d)
if n > 0 {
dstP += n
return dst[:dstP]
}
// Not compressible
dstP += emitLiteral(dst[dstP:], src)
return dst[:dstP]
}
// EncodeBest returns the encoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire encoded block.
// Otherwise, a newly allocated slice will be returned.
//
// EncodeBest compresses as good as reasonably possible but with a
// big speed decrease.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func (d *Dict) EncodeBest(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if len(dst) < n {
dst = make([]byte, n)
}
// The block starts with the varint-encoded length of the decompressed bytes.
dstP := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:dstP]
}
if len(src) < minNonLiteralBlockSize {
dstP += emitLiteral(dst[dstP:], src)
return dst[:dstP]
}
n := encodeBlockBest(dst[dstP:], src, d)
if n > 0 {
dstP += n
return dst[:dstP]
}
// Not compressible
dstP += emitLiteral(dst[dstP:], src)
return dst[:dstP]
}
// Decode returns the decoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire decoded block.
// Otherwise, a newly allocated slice will be returned.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
func (d *Dict) Decode(dst, src []byte) ([]byte, error) {
dLen, s, err := decodedLen(src)
if err != nil {
return nil, err
}
if dLen <= cap(dst) {
dst = dst[:dLen]
} else {
dst = make([]byte, dLen)
}
if s2DecodeDict(dst, src[s:], d) != 0 {
return nil, ErrCorrupt
}
return dst, nil
}
func (d *Dict) initFast() {
d.fast.Do(func() {
const (
tableBits = 14
maxTableSize = 1 << tableBits
)
var table [maxTableSize]uint16
// We stop so any entry of length 8 can always be read.
for i := 0; i < len(d.dict)-8-2; i += 3 {
x0 := load64(d.dict, i)
h0 := hash6(x0, tableBits)
h1 := hash6(x0>>8, tableBits)
h2 := hash6(x0>>16, tableBits)
table[h0] = uint16(i)
table[h1] = uint16(i + 1)
table[h2] = uint16(i + 2)
}
d.fastTable = &table
})
}
func (d *Dict) initBetter() {
d.better.Do(func() {
const (
// Long hash matches.
lTableBits = 17
maxLTableSize = 1 << lTableBits
// Short hash matches.
sTableBits = 14
maxSTableSize = 1 << sTableBits
)
var lTable [maxLTableSize]uint16
var sTable [maxSTableSize]uint16
// We stop so any entry of length 8 can always be read.
for i := 0; i < len(d.dict)-8; i++ {
cv := load64(d.dict, i)
lTable[hash7(cv, lTableBits)] = uint16(i)
sTable[hash4(cv, sTableBits)] = uint16(i)
}
d.betterTableShort = &sTable
d.betterTableLong = &lTable
})
}
func (d *Dict) initBest() {
d.best.Do(func() {
const (
// Long hash matches.
lTableBits = 19
maxLTableSize = 1 << lTableBits
// Short hash matches.
sTableBits = 16
maxSTableSize = 1 << sTableBits
)
var lTable [maxLTableSize]uint32
var sTable [maxSTableSize]uint32
// We stop so any entry of length 8 can always be read.
for i := 0; i < len(d.dict)-8; i++ {
cv := load64(d.dict, i)
hashL := hash8(cv, lTableBits)
hashS := hash4(cv, sTableBits)
candidateL := lTable[hashL]
candidateS := sTable[hashS]
lTable[hashL] = uint32(i) | candidateL<<16
sTable[hashS] = uint32(i) | candidateS<<16
}
d.bestTableShort = &sTable
d.bestTableLong = &lTable
})
}
Server/vendor/github.com/klauspost/compress/s2/encode.go
Generated Vendored
+418
View File
@@ -0,0 +1,418 @@
// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package s2
import (
"encoding/binary"
"math"
"math/bits"
"sync"
"github.com/klauspost/compress/internal/race"
)
// Encode returns the encoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire encoded block.
// Otherwise, a newly allocated slice will be returned.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func Encode(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if cap(dst) < n {
dst = make([]byte, n)
} else {
dst = dst[:n]
}
// The block starts with the varint-encoded length of the decompressed bytes.
d := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:d]
}
if len(src) < minNonLiteralBlockSize {
d += emitLiteral(dst[d:], src)
return dst[:d]
}
n := encodeBlock(dst[d:], src)
if n > 0 {
d += n
return dst[:d]
}
// Not compressible
d += emitLiteral(dst[d:], src)
return dst[:d]
}
var estblockPool [2]sync.Pool
// EstimateBlockSize will perform a very fast compression
// without outputting the result and return the compressed output size.
// The function returns -1 if no improvement could be achieved.
// Using actual compression will most often produce better compression than the estimate.
func EstimateBlockSize(src []byte) (d int) {
if len(src) <= inputMargin || int64(len(src)) > 0xffffffff {
return -1
}
if len(src) <= 1024 {
const sz, pool = 2048, 0
tmp, ok := estblockPool[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer estblockPool[pool].Put(tmp)
d = calcBlockSizeSmall(src, tmp)
} else {
const sz, pool = 32768, 1
tmp, ok := estblockPool[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer estblockPool[pool].Put(tmp)
d = calcBlockSize(src, tmp)
}
if d == 0 {
return -1
}
// Size of the varint encoded block size.
d += (bits.Len64(uint64(len(src))) + 7) / 7
if d >= len(src) {
return -1
}
return d
}
// EncodeBetter returns the encoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire encoded block.
// Otherwise, a newly allocated slice will be returned.
//
// EncodeBetter compresses better than Encode but typically with a
// 10-40% speed decrease on both compression and decompression.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func EncodeBetter(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if cap(dst) < n {
dst = make([]byte, n)
} else {
dst = dst[:n]
}
// The block starts with the varint-encoded length of the decompressed bytes.
d := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:d]
}
if len(src) < minNonLiteralBlockSize {
d += emitLiteral(dst[d:], src)
return dst[:d]
}
n := encodeBlockBetter(dst[d:], src)
if n > 0 {
d += n
return dst[:d]
}
// Not compressible
d += emitLiteral(dst[d:], src)
return dst[:d]
}
// EncodeBest returns the encoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire encoded block.
// Otherwise, a newly allocated slice will be returned.
//
// EncodeBest compresses as good as reasonably possible but with a
// big speed decrease.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func EncodeBest(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if cap(dst) < n {
dst = make([]byte, n)
} else {
dst = dst[:n]
}
// The block starts with the varint-encoded length of the decompressed bytes.
d := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:d]
}
if len(src) < minNonLiteralBlockSize {
d += emitLiteral(dst[d:], src)
return dst[:d]
}
n := encodeBlockBest(dst[d:], src, nil)
if n > 0 {
d += n
return dst[:d]
}
// Not compressible
d += emitLiteral(dst[d:], src)
return dst[:d]
}
// EncodeSnappy returns the encoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire encoded block.
// Otherwise, a newly allocated slice will be returned.
//
// The output is Snappy compatible and will likely decompress faster.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func EncodeSnappy(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if cap(dst) < n {
dst = make([]byte, n)
} else {
dst = dst[:n]
}
// The block starts with the varint-encoded length of the decompressed bytes.
d := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:d]
}
if len(src) < minNonLiteralBlockSize {
d += emitLiteral(dst[d:], src)
return dst[:d]
}
n := encodeBlockSnappy(dst[d:], src)
if n > 0 {
d += n
return dst[:d]
}
// Not compressible
d += emitLiteral(dst[d:], src)
return dst[:d]
}
// EncodeSnappyBetter returns the encoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire encoded block.
// Otherwise, a newly allocated slice will be returned.
//
// The output is Snappy compatible and will likely decompress faster.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func EncodeSnappyBetter(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if cap(dst) < n {
dst = make([]byte, n)
} else {
dst = dst[:n]
}
// The block starts with the varint-encoded length of the decompressed bytes.
d := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:d]
}
if len(src) < minNonLiteralBlockSize {
d += emitLiteral(dst[d:], src)
return dst[:d]
}
n := encodeBlockBetterSnappy(dst[d:], src)
if n > 0 {
d += n
return dst[:d]
}
// Not compressible
d += emitLiteral(dst[d:], src)
return dst[:d]
}
// EncodeSnappyBest returns the encoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire encoded block.
// Otherwise, a newly allocated slice will be returned.
//
// The output is Snappy compatible and will likely decompress faster.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func EncodeSnappyBest(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if cap(dst) < n {
dst = make([]byte, n)
} else {
dst = dst[:n]
}
// The block starts with the varint-encoded length of the decompressed bytes.
d := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:d]
}
if len(src) < minNonLiteralBlockSize {
d += emitLiteral(dst[d:], src)
return dst[:d]
}
n := encodeBlockBestSnappy(dst[d:], src)
if n > 0 {
d += n
return dst[:d]
}
// Not compressible
d += emitLiteral(dst[d:], src)
return dst[:d]
}
// ConcatBlocks will concatenate the supplied blocks and append them to the supplied destination.
// If the destination is nil or too small, a new will be allocated.
// The blocks are not validated, so garbage in = garbage out.
// dst may not overlap block data.
// Any data in dst is preserved as is, so it will not be considered a block.
func ConcatBlocks(dst []byte, blocks ...[]byte) ([]byte, error) {
totalSize := uint64(0)
compSize := 0
for _, b := range blocks {
l, hdr, err := decodedLen(b)
if err != nil {
return nil, err
}
totalSize += uint64(l)
compSize += len(b) - hdr
}
if totalSize == 0 {
dst = append(dst, 0)
return dst, nil
}
if totalSize > math.MaxUint32 {
return nil, ErrTooLarge
}
var tmp [binary.MaxVarintLen32]byte
hdrSize := binary.PutUvarint(tmp[:], totalSize)
wantSize := hdrSize + compSize
if cap(dst)-len(dst) < wantSize {
dst = append(make([]byte, 0, wantSize+len(dst)), dst...)
}
dst = append(dst, tmp[:hdrSize]...)
for _, b := range blocks {
_, hdr, err := decodedLen(b)
if err != nil {
return nil, err
}
dst = append(dst, b[hdr:]...)
}
return dst, nil
}
// inputMargin is the minimum number of extra input bytes to keep, inside
// encodeBlock's inner loop. On some architectures, this margin lets us
// implement a fast path for emitLiteral, where the copy of short (<= 16 byte)
// literals can be implemented as a single load to and store from a 16-byte
// register. That literal's actual length can be as short as 1 byte, so this
// can copy up to 15 bytes too much, but that's OK as subsequent iterations of
// the encoding loop will fix up the copy overrun, and this inputMargin ensures
// that we don't overrun the dst and src buffers.
const inputMargin = 8
// minNonLiteralBlockSize is the minimum size of the input to encodeBlock that
// will be accepted by the encoder.
const minNonLiteralBlockSize = 32
const intReduction = 2 - (1 << (^uint(0) >> 63)) // 1 (32 bits) or 0 (64 bits)
// MaxBlockSize is the maximum value where MaxEncodedLen will return a valid block size.
// Blocks this big are highly discouraged, though.
// Half the size on 32 bit systems.
const MaxBlockSize = (1<<(32-intReduction) - 1) - binary.MaxVarintLen32 - 5
// MaxEncodedLen returns the maximum length of a snappy block, given its
// uncompressed length.
//
// It will return a negative value if srcLen is too large to encode.
// 32 bit platforms will have lower thresholds for rejecting big content.
func MaxEncodedLen(srcLen int) int {
n := uint64(srcLen)
if intReduction == 1 {
// 32 bits
if n > math.MaxInt32 {
// Also includes negative.
return -1
}
} else if n > 0xffffffff {
// 64 bits
// Also includes negative.
return -1
}
// Size of the varint encoded block size.
n = n + uint64((bits.Len64(n)+7)/7)
// Add maximum size of encoding block as literals.
n += uint64(literalExtraSize(int64(srcLen)))
if intReduction == 1 {
// 32 bits
if n > math.MaxInt32 {
return -1
}
} else if n > 0xffffffff {
// 64 bits
// Also includes negative.
return -1
}
return int(n)
}
Server/vendor/github.com/klauspost/compress/s2/encode_all.go
Generated Vendored
+1477
View File
File diff suppressed because it is too large Load Diff
Server/vendor/github.com/klauspost/compress/s2/encode_amd64.go
Generated Vendored
+316
View File
@@ -0,0 +1,316 @@
//go:build !appengine && !noasm && gc
package s2
import (
"sync"
"github.com/klauspost/compress/internal/race"
)
const hasAmd64Asm = true
var encPools [4]sync.Pool
// encodeBlock encodes a non-empty src to a guaranteed-large-enough dst. It
// assumes that the varint-encoded length of the decompressed bytes has already
// been written.
//
// It also assumes that:
//
// len(dst) >= MaxEncodedLen(len(src)) &&
// minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize
func encodeBlock(dst, src []byte) (d int) {
race.ReadSlice(src)
race.WriteSlice(dst)
const (
// Use 12 bit table when less than...
limit12B = 16 << 10
// Use 10 bit table when less than...
limit10B = 4 << 10
// Use 8 bit table when less than...
limit8B = 512
)
if len(src) >= 4<<20 {
const sz, pool = 65536, 0
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeBlockAsm(dst, src, tmp)
}
if len(src) >= limit12B {
const sz, pool = 65536, 0
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeBlockAsm4MB(dst, src, tmp)
}
if len(src) >= limit10B {
const sz, pool = 16384, 1
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeBlockAsm12B(dst, src, tmp)
}
if len(src) >= limit8B {
const sz, pool = 4096, 2
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeBlockAsm10B(dst, src, tmp)
}
if len(src) < minNonLiteralBlockSize {
return 0
}
const sz, pool = 1024, 3
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeBlockAsm8B(dst, src, tmp)
}
var encBetterPools [5]sync.Pool
// encodeBlockBetter encodes a non-empty src to a guaranteed-large-enough dst. It
// assumes that the varint-encoded length of the decompressed bytes has already
// been written.
//
// It also assumes that:
//
// len(dst) >= MaxEncodedLen(len(src)) &&
// minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize
func encodeBlockBetter(dst, src []byte) (d int) {
race.ReadSlice(src)
race.WriteSlice(dst)
const (
// Use 12 bit table when less than...
limit12B = 16 << 10
// Use 10 bit table when less than...
limit10B = 4 << 10
// Use 8 bit table when less than...
limit8B = 512
)
if len(src) > 4<<20 {
const sz, pool = 589824, 0
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeBetterBlockAsm(dst, src, tmp)
}
if len(src) >= limit12B {
const sz, pool = 589824, 0
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeBetterBlockAsm4MB(dst, src, tmp)
}
if len(src) >= limit10B {
const sz, pool = 81920, 0
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeBetterBlockAsm12B(dst, src, tmp)
}
if len(src) >= limit8B {
const sz, pool = 20480, 1
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeBetterBlockAsm10B(dst, src, tmp)
}
if len(src) < minNonLiteralBlockSize {
return 0
}
const sz, pool = 5120, 2
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeBetterBlockAsm8B(dst, src, tmp)
}
// encodeBlockSnappy encodes a non-empty src to a guaranteed-large-enough dst. It
// assumes that the varint-encoded length of the decompressed bytes has already
// been written.
//
// It also assumes that:
//
// len(dst) >= MaxEncodedLen(len(src)) &&
// minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize
func encodeBlockSnappy(dst, src []byte) (d int) {
race.ReadSlice(src)
race.WriteSlice(dst)
const (
// Use 12 bit table when less than...
limit12B = 16 << 10
// Use 10 bit table when less than...
limit10B = 4 << 10
// Use 8 bit table when less than...
limit8B = 512
)
if len(src) > 65536 {
const sz, pool = 65536, 0
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeSnappyBlockAsm(dst, src, tmp)
}
if len(src) >= limit12B {
const sz, pool = 65536, 0
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeSnappyBlockAsm64K(dst, src, tmp)
}
if len(src) >= limit10B {
const sz, pool = 16384, 1
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeSnappyBlockAsm12B(dst, src, tmp)
}
if len(src) >= limit8B {
const sz, pool = 4096, 2
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeSnappyBlockAsm10B(dst, src, tmp)
}
if len(src) < minNonLiteralBlockSize {
return 0
}
const sz, pool = 1024, 3
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeSnappyBlockAsm8B(dst, src, tmp)
}
// encodeBlockSnappy encodes a non-empty src to a guaranteed-large-enough dst. It
// assumes that the varint-encoded length of the decompressed bytes has already
// been written.
//
// It also assumes that:
//
// len(dst) >= MaxEncodedLen(len(src)) &&
// minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize
func encodeBlockBetterSnappy(dst, src []byte) (d int) {
race.ReadSlice(src)
race.WriteSlice(dst)
const (
// Use 12 bit table when less than...
limit12B = 16 << 10
// Use 10 bit table when less than...
limit10B = 4 << 10
// Use 8 bit table when less than...
limit8B = 512
)
if len(src) > 65536 {
const sz, pool = 589824, 0
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeSnappyBetterBlockAsm(dst, src, tmp)
}
if len(src) >= limit12B {
const sz, pool = 294912, 4
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeSnappyBetterBlockAsm64K(dst, src, tmp)
}
if len(src) >= limit10B {
const sz, pool = 81920, 0
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeSnappyBetterBlockAsm12B(dst, src, tmp)
}
if len(src) >= limit8B {
const sz, pool = 20480, 1
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeSnappyBetterBlockAsm10B(dst, src, tmp)
}
if len(src) < minNonLiteralBlockSize {
return 0
}
const sz, pool = 5120, 2
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeSnappyBetterBlockAsm8B(dst, src, tmp)
}
Server/vendor/github.com/klauspost/compress/s2/encode_best.go
Generated Vendored
+793
View File
@@ -0,0 +1,793 @@
// Copyright 2016 The Snappy-Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package s2
import (
"fmt"
"math"
"math/bits"
)
// encodeBlockBest encodes a non-empty src to a guaranteed-large-enough dst. It
// assumes that the varint-encoded length of the decompressed bytes has already
// been written.
//
// It also assumes that:
//
// len(dst) >= MaxEncodedLen(len(src)) &&
// minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize
func encodeBlockBest(dst, src []byte, dict *Dict) (d int) {
// Initialize the hash tables.
const (
// Long hash matches.
lTableBits = 19
maxLTableSize = 1 << lTableBits
// Short hash matches.
sTableBits = 16
maxSTableSize = 1 << sTableBits
inputMargin = 8 + 2
debug = false
)
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := len(src) - inputMargin
if len(src) < minNonLiteralBlockSize {
return 0
}
sLimitDict := min(len(src)-inputMargin, MaxDictSrcOffset-inputMargin)
var lTable [maxLTableSize]uint64
var sTable [maxSTableSize]uint64
// Bail if we can't compress to at least this.
dstLimit := len(src) - 5
// nextEmit is where in src the next emitLiteral should start from.
nextEmit := 0
// The encoded form must start with a literal, as there are no previous
// bytes to copy, so we start looking for hash matches at s == 1.
s := 1
repeat := 1
if dict != nil {
dict.initBest()
s = 0
repeat = len(dict.dict) - dict.repeat
}
cv := load64(src, s)
// We search for a repeat at -1, but don't output repeats when nextEmit == 0
const lowbitMask = 0xffffffff
getCur := func(x uint64) int {
return int(x & lowbitMask)
}
getPrev := func(x uint64) int {
return int(x >> 32)
}
const maxSkip = 64
for {
type match struct {
offset int
s int
length int
score int
rep, dict bool
}
var best match
for {
// Next src position to check
nextS := (s-nextEmit)>>8 + 1
if nextS > maxSkip {
nextS = s + maxSkip
} else {
nextS += s
}
if nextS > sLimit {
goto emitRemainder
}
if dict != nil && s >= MaxDictSrcOffset {
dict = nil
if repeat > s {
repeat = math.MinInt32
}
}
hashL := hash8(cv, lTableBits)
hashS := hash4(cv, sTableBits)
candidateL := lTable[hashL]
candidateS := sTable[hashS]
score := func(m match) int {
// Matches that are longer forward are penalized since we must emit it as a literal.
score := m.length - m.s
if nextEmit == m.s {
// If we do not have to emit literals, we save 1 byte
score++
}
offset := m.s - m.offset
if m.rep {
return score - emitRepeatSize(offset, m.length)
}
return score - emitCopySize(offset, m.length)
}
matchAt := func(offset, s int, first uint32, rep bool) match {
if best.length != 0 && best.s-best.offset == s-offset {
// Don't retest if we have the same offset.
return match{offset: offset, s: s}
}
if load32(src, offset) != first {
return match{offset: offset, s: s}
}
m := match{offset: offset, s: s, length: 4 + offset, rep: rep}
s += 4
for s < len(src) {
if len(src)-s < 8 {
if src[s] == src[m.length] {
m.length++
s++
continue
}
break
}
if diff := load64(src, s) ^ load64(src, m.length); diff != 0 {
m.length += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
m.length += 8
}
m.length -= offset
m.score = score(m)
if m.score <= -m.s {
// Eliminate if no savings, we might find a better one.
m.length = 0
}
return m
}
matchDict := func(candidate, s int, first uint32, rep bool) match {
if s >= MaxDictSrcOffset {
return match{offset: candidate, s: s}
}
// Calculate offset as if in continuous array with s
offset := -len(dict.dict) + candidate
if best.length != 0 && best.s-best.offset == s-offset && !rep {
// Don't retest if we have the same offset.
return match{offset: offset, s: s}
}
if load32(dict.dict, candidate) != first {
return match{offset: offset, s: s}
}
m := match{offset: offset, s: s, length: 4 + candidate, rep: rep, dict: true}
s += 4
if !rep {
for s < sLimitDict && m.length < len(dict.dict) {
if len(src)-s < 8 || len(dict.dict)-m.length < 8 {
if src[s] == dict.dict[m.length] {
m.length++
s++
continue
}
break
}
if diff := load64(src, s) ^ load64(dict.dict, m.length); diff != 0 {
m.length += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
m.length += 8
}
} else {
for s < len(src) && m.length < len(dict.dict) {
if len(src)-s < 8 || len(dict.dict)-m.length < 8 {
if src[s] == dict.dict[m.length] {
m.length++
s++
continue
}
break
}
if diff := load64(src, s) ^ load64(dict.dict, m.length); diff != 0 {
m.length += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
m.length += 8
}
}
m.length -= candidate
m.score = score(m)
if m.score <= -m.s {
// Eliminate if no savings, we might find a better one.
m.length = 0
}
return m
}
bestOf := func(a, b match) match {
if b.length == 0 {
return a
}
if a.length == 0 {
return b
}
as := a.score + b.s
bs := b.score + a.s
if as >= bs {
return a
}
return b
}
if s > 0 {
best = bestOf(matchAt(getCur(candidateL), s, uint32(cv), false), matchAt(getPrev(candidateL), s, uint32(cv), false))
best = bestOf(best, matchAt(getCur(candidateS), s, uint32(cv), false))
best = bestOf(best, matchAt(getPrev(candidateS), s, uint32(cv), false))
}
if dict != nil {
candidateL := dict.bestTableLong[hashL]
candidateS := dict.bestTableShort[hashS]
best = bestOf(best, matchDict(int(candidateL&0xffff), s, uint32(cv), false))
best = bestOf(best, matchDict(int(candidateL>>16), s, uint32(cv), false))
best = bestOf(best, matchDict(int(candidateS&0xffff), s, uint32(cv), false))
best = bestOf(best, matchDict(int(candidateS>>16), s, uint32(cv), false))
}
{
if (dict == nil || repeat <= s) && repeat > 0 {
best = bestOf(best, matchAt(s-repeat+1, s+1, uint32(cv>>8), true))
} else if s-repeat < -4 && dict != nil {
candidate := len(dict.dict) - (repeat - s)
best = bestOf(best, matchDict(candidate, s, uint32(cv), true))
candidate++
best = bestOf(best, matchDict(candidate, s+1, uint32(cv>>8), true))
}
if best.length > 0 {
hashS := hash4(cv>>8, sTableBits)
// s+1
nextShort := sTable[hashS]
s := s + 1
cv := load64(src, s)
hashL := hash8(cv, lTableBits)
nextLong := lTable[hashL]
best = bestOf(best, matchAt(getCur(nextShort), s, uint32(cv), false))
best = bestOf(best, matchAt(getPrev(nextShort), s, uint32(cv), false))
best = bestOf(best, matchAt(getCur(nextLong), s, uint32(cv), false))
best = bestOf(best, matchAt(getPrev(nextLong), s, uint32(cv), false))
// Dict at + 1
if dict != nil {
candidateL := dict.bestTableLong[hashL]
candidateS := dict.bestTableShort[hashS]
best = bestOf(best, matchDict(int(candidateL&0xffff), s, uint32(cv), false))
best = bestOf(best, matchDict(int(candidateS&0xffff), s, uint32(cv), false))
}
// s+2
if true {
hashS := hash4(cv>>8, sTableBits)
nextShort = sTable[hashS]
s++
cv = load64(src, s)
hashL := hash8(cv, lTableBits)
nextLong = lTable[hashL]
if (dict == nil || repeat <= s) && repeat > 0 {
// Repeat at + 2
best = bestOf(best, matchAt(s-repeat, s, uint32(cv), true))
} else if repeat-s > 4 && dict != nil {
candidate := len(dict.dict) - (repeat - s)
best = bestOf(best, matchDict(candidate, s, uint32(cv), true))
}
best = bestOf(best, matchAt(getCur(nextShort), s, uint32(cv), false))
best = bestOf(best, matchAt(getPrev(nextShort), s, uint32(cv), false))
best = bestOf(best, matchAt(getCur(nextLong), s, uint32(cv), false))
best = bestOf(best, matchAt(getPrev(nextLong), s, uint32(cv), false))
// Dict at +2
// Very small gain
if dict != nil {
candidateL := dict.bestTableLong[hashL]
candidateS := dict.bestTableShort[hashS]
best = bestOf(best, matchDict(int(candidateL&0xffff), s, uint32(cv), false))
best = bestOf(best, matchDict(int(candidateS&0xffff), s, uint32(cv), false))
}
}
// Search for a match at best match end, see if that is better.
// Allow some bytes at the beginning to mismatch.
// Sweet spot is around 1-2 bytes, but depends on input.
// The skipped bytes are tested in Extend backwards,
// and still picked up as part of the match if they do.
const skipBeginning = 2
const skipEnd = 1
if sAt := best.s + best.length - skipEnd; sAt < sLimit {
sBack := best.s + skipBeginning - skipEnd
backL := best.length - skipBeginning
// Load initial values
cv = load64(src, sBack)
// Grab candidates...
next := lTable[hash8(load64(src, sAt), lTableBits)]
if checkAt := getCur(next) - backL; checkAt > 0 {
best = bestOf(best, matchAt(checkAt, sBack, uint32(cv), false))
}
if checkAt := getPrev(next) - backL; checkAt > 0 {
best = bestOf(best, matchAt(checkAt, sBack, uint32(cv), false))
}
// Disabled: Extremely small gain
if false {
next = sTable[hash4(load64(src, sAt), sTableBits)]
if checkAt := getCur(next) - backL; checkAt > 0 {
best = bestOf(best, matchAt(checkAt, sBack, uint32(cv), false))
}
if checkAt := getPrev(next) - backL; checkAt > 0 {
best = bestOf(best, matchAt(checkAt, sBack, uint32(cv), false))
}
}
}
}
}
// Update table
lTable[hashL] = uint64(s) | candidateL<<32
sTable[hashS] = uint64(s) | candidateS<<32
if best.length > 0 {
break
}
cv = load64(src, nextS)
s = nextS
}
// Extend backwards, not needed for repeats...
s = best.s
if !best.rep && !best.dict {
for best.offset > 0 && s > nextEmit && src[best.offset-1] == src[s-1] {
best.offset--
best.length++
s--
}
}
if false && best.offset >= s {
panic(fmt.Errorf("t %d >= s %d", best.offset, s))
}
// Bail if we exceed the maximum size.
if d+(s-nextEmit) > dstLimit {
return 0
}
base := s
offset := s - best.offset
s += best.length
if offset > 65535 && s-base <= 5 && !best.rep {
// Bail if the match is equal or worse to the encoding.
s = best.s + 1
if s >= sLimit {
goto emitRemainder
}
cv = load64(src, s)
continue
}
if debug && nextEmit != base {
fmt.Println("EMIT", base-nextEmit, "literals. base-after:", base)
}
d += emitLiteral(dst[d:], src[nextEmit:base])
if best.rep {
if nextEmit > 0 || best.dict {
if debug {
fmt.Println("REPEAT, length", best.length, "offset:", offset, "s-after:", s, "dict:", best.dict, "best:", best)
}
// same as `add := emitCopy(dst[d:], repeat, s-base)` but skips storing offset.
d += emitRepeat(dst[d:], offset, best.length)
} else {
// First match without dict cannot be a repeat.
if debug {
fmt.Println("COPY, length", best.length, "offset:", offset, "s-after:", s, "dict:", best.dict, "best:", best)
}
d += emitCopy(dst[d:], offset, best.length)
}
} else {
if debug {
fmt.Println("COPY, length", best.length, "offset:", offset, "s-after:", s, "dict:", best.dict, "best:", best)
}
d += emitCopy(dst[d:], offset, best.length)
}
repeat = offset
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
if d > dstLimit {
// Do we have space for more, if not bail.
return 0
}
// Fill tables...
for i := best.s + 1; i < s; i++ {
cv0 := load64(src, i)
long0 := hash8(cv0, lTableBits)
short0 := hash4(cv0, sTableBits)
lTable[long0] = uint64(i) | lTable[long0]<<32
sTable[short0] = uint64(i) | sTable[short0]<<32
}
cv = load64(src, s)
}
emitRemainder:
if nextEmit < len(src) {
// Bail if we exceed the maximum size.
if d+len(src)-nextEmit > dstLimit {
return 0
}
if debug && nextEmit != s {
fmt.Println("emitted ", len(src)-nextEmit, "literals")
}
d += emitLiteral(dst[d:], src[nextEmit:])
}
return d
}
// encodeBlockBestSnappy encodes a non-empty src to a guaranteed-large-enough dst. It
// assumes that the varint-encoded length of the decompressed bytes has already
// been written.
//
// It also assumes that:
//
// len(dst) >= MaxEncodedLen(len(src)) &&
// minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize
func encodeBlockBestSnappy(dst, src []byte) (d int) {
// Initialize the hash tables.
const (
// Long hash matches.
lTableBits = 19
maxLTableSize = 1 << lTableBits
// Short hash matches.
sTableBits = 16
maxSTableSize = 1 << sTableBits
inputMargin = 8 + 2
)
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := len(src) - inputMargin
if len(src) < minNonLiteralBlockSize {
return 0
}
var lTable [maxLTableSize]uint64
var sTable [maxSTableSize]uint64
// Bail if we can't compress to at least this.
dstLimit := len(src) - 5
// nextEmit is where in src the next emitLiteral should start from.
nextEmit := 0
// The encoded form must start with a literal, as there are no previous
// bytes to copy, so we start looking for hash matches at s == 1.
s := 1
cv := load64(src, s)
// We search for a repeat at -1, but don't output repeats when nextEmit == 0
repeat := 1
const lowbitMask = 0xffffffff
getCur := func(x uint64) int {
return int(x & lowbitMask)
}
getPrev := func(x uint64) int {
return int(x >> 32)
}
const maxSkip = 64
for {
type match struct {
offset int
s int
length int
score int
}
var best match
for {
// Next src position to check
nextS := (s-nextEmit)>>8 + 1
if nextS > maxSkip {
nextS = s + maxSkip
} else {
nextS += s
}
if nextS > sLimit {
goto emitRemainder
}
hashL := hash8(cv, lTableBits)
hashS := hash4(cv, sTableBits)
candidateL := lTable[hashL]
candidateS := sTable[hashS]
score := func(m match) int {
// Matches that are longer forward are penalized since we must emit it as a literal.
score := m.length - m.s
if nextEmit == m.s {
// If we do not have to emit literals, we save 1 byte
score++
}
offset := m.s - m.offset
return score - emitCopyNoRepeatSize(offset, m.length)
}
matchAt := func(offset, s int, first uint32) match {
if best.length != 0 && best.s-best.offset == s-offset {
// Don't retest if we have the same offset.
return match{offset: offset, s: s}
}
if load32(src, offset) != first {
return match{offset: offset, s: s}
}
m := match{offset: offset, s: s, length: 4 + offset}
s += 4
for s <= sLimit {
if diff := load64(src, s) ^ load64(src, m.length); diff != 0 {
m.length += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
m.length += 8
}
m.length -= offset
m.score = score(m)
if m.score <= -m.s {
// Eliminate if no savings, we might find a better one.
m.length = 0
}
return m
}
bestOf := func(a, b match) match {
if b.length == 0 {
return a
}
if a.length == 0 {
return b
}
as := a.score + b.s
bs := b.score + a.s
if as >= bs {
return a
}
return b
}
best = bestOf(matchAt(getCur(candidateL), s, uint32(cv)), matchAt(getPrev(candidateL), s, uint32(cv)))
best = bestOf(best, matchAt(getCur(candidateS), s, uint32(cv)))
best = bestOf(best, matchAt(getPrev(candidateS), s, uint32(cv)))
{
best = bestOf(best, matchAt(s-repeat+1, s+1, uint32(cv>>8)))
if best.length > 0 {
// s+1
nextShort := sTable[hash4(cv>>8, sTableBits)]
s := s + 1
cv := load64(src, s)
nextLong := lTable[hash8(cv, lTableBits)]
best = bestOf(best, matchAt(getCur(nextShort), s, uint32(cv)))
best = bestOf(best, matchAt(getPrev(nextShort), s, uint32(cv)))
best = bestOf(best, matchAt(getCur(nextLong), s, uint32(cv)))
best = bestOf(best, matchAt(getPrev(nextLong), s, uint32(cv)))
// Repeat at + 2
best = bestOf(best, matchAt(s-repeat+1, s+1, uint32(cv>>8)))
// s+2
if true {
nextShort = sTable[hash4(cv>>8, sTableBits)]
s++
cv = load64(src, s)
nextLong = lTable[hash8(cv, lTableBits)]
best = bestOf(best, matchAt(getCur(nextShort), s, uint32(cv)))
best = bestOf(best, matchAt(getPrev(nextShort), s, uint32(cv)))
best = bestOf(best, matchAt(getCur(nextLong), s, uint32(cv)))
best = bestOf(best, matchAt(getPrev(nextLong), s, uint32(cv)))
}
// Search for a match at best match end, see if that is better.
if sAt := best.s + best.length; sAt < sLimit {
sBack := best.s
backL := best.length
// Load initial values
cv = load64(src, sBack)
// Search for mismatch
next := lTable[hash8(load64(src, sAt), lTableBits)]
//next := sTable[hash4(load64(src, sAt), sTableBits)]
if checkAt := getCur(next) - backL; checkAt > 0 {
best = bestOf(best, matchAt(checkAt, sBack, uint32(cv)))
}
if checkAt := getPrev(next) - backL; checkAt > 0 {
best = bestOf(best, matchAt(checkAt, sBack, uint32(cv)))
}
}
}
}
// Update table
lTable[hashL] = uint64(s) | candidateL<<32
sTable[hashS] = uint64(s) | candidateS<<32
if best.length > 0 {
break
}
cv = load64(src, nextS)
s = nextS
}
// Extend backwards, not needed for repeats...
s = best.s
if true {
for best.offset > 0 && s > nextEmit && src[best.offset-1] == src[s-1] {
best.offset--
best.length++
s--
}
}
if false && best.offset >= s {
panic(fmt.Errorf("t %d >= s %d", best.offset, s))
}
// Bail if we exceed the maximum size.
if d+(s-nextEmit) > dstLimit {
return 0
}
base := s
offset := s - best.offset
s += best.length
if offset > 65535 && s-base <= 5 {
// Bail if the match is equal or worse to the encoding.
s = best.s + 1
if s >= sLimit {
goto emitRemainder
}
cv = load64(src, s)
continue
}
d += emitLiteral(dst[d:], src[nextEmit:base])
d += emitCopyNoRepeat(dst[d:], offset, best.length)
repeat = offset
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
if d > dstLimit {
// Do we have space for more, if not bail.
return 0
}
// Fill tables...
for i := best.s + 1; i < s; i++ {
cv0 := load64(src, i)
long0 := hash8(cv0, lTableBits)
short0 := hash4(cv0, sTableBits)
lTable[long0] = uint64(i) | lTable[long0]<<32
sTable[short0] = uint64(i) | sTable[short0]<<32
}
cv = load64(src, s)
}
emitRemainder:
if nextEmit < len(src) {
// Bail if we exceed the maximum size.
if d+len(src)-nextEmit > dstLimit {
return 0
}
d += emitLiteral(dst[d:], src[nextEmit:])
}
return d
}
// emitCopySize returns the size to encode the offset+length
//
// It assumes that:
//
// 1 <= offset && offset <= math.MaxUint32
// 4 <= length && length <= 1 << 24
func emitCopySize(offset, length int) int {
if offset >= 65536 {
i := 0
if length > 64 {
length -= 64
if length >= 4 {
// Emit remaining as repeats
return 5 + emitRepeatSize(offset, length)
}
i = 5
}
if length == 0 {
return i
}
return i + 5
}
// Offset no more than 2 bytes.
if length > 64 {
if offset < 2048 {
// Emit 8 bytes, then rest as repeats...
return 2 + emitRepeatSize(offset, length-8)
}
// Emit remaining as repeats, at least 4 bytes remain.
return 3 + emitRepeatSize(offset, length-60)
}
if length >= 12 || offset >= 2048 {
return 3
}
// Emit the remaining copy, encoded as 2 bytes.
return 2
}
// emitCopyNoRepeatSize returns the size to encode the offset+length
//
// It assumes that:
//
// 1 <= offset && offset <= math.MaxUint32
// 4 <= length && length <= 1 << 24
func emitCopyNoRepeatSize(offset, length int) int {
if offset >= 65536 {
return 5 + 5*(length/64)
}
// Offset no more than 2 bytes.
if length > 64 {
// Emit remaining as repeats, at least 4 bytes remain.
return 3 + 3*(length/60)
}
if length >= 12 || offset >= 2048 {
return 3
}
// Emit the remaining copy, encoded as 2 bytes.
return 2
}
// emitRepeatSize returns the number of bytes required to encode a repeat.
// Length must be at least 4 and < 1<<24
func emitRepeatSize(offset, length int) int {
// Repeat offset, make length cheaper
if length <= 4+4 || (length < 8+4 && offset < 2048) {
return 2
}
if length < (1<<8)+4+4 {
return 3
}
if length < (1<<16)+(1<<8)+4 {
return 4
}
const maxRepeat = (1 << 24) - 1
length -= (1 << 16) - 4
left := 0
if length > maxRepeat {
left = length - maxRepeat + 4
}
if left > 0 {
return 5 + emitRepeatSize(offset, left)
}
return 5
}
Server/vendor/github.com/klauspost/compress/s2/encode_better.go
Generated Vendored
+1507
View File
File diff suppressed because it is too large Load Diff
Server/vendor/github.com/klauspost/compress/s2/encode_go.go
Generated Vendored
+740
View File
@@ -0,0 +1,740 @@
//go:build !amd64 || appengine || !gc || noasm
package s2
import (
"bytes"
"math/bits"
)
const hasAmd64Asm = false
// encodeBlock encodes a non-empty src to a guaranteed-large-enough dst. It
// assumes that the varint-encoded length of the decompressed bytes has already
// been written.
//
// It also assumes that:
//
// len(dst) >= MaxEncodedLen(len(src))
func encodeBlock(dst, src []byte) (d int) {
if len(src) < minNonLiteralBlockSize {
return 0
}
if len(src) <= 64<<10 {
return encodeBlockGo64K(dst, src)
}
return encodeBlockGo(dst, src)
}
// encodeBlockBetter encodes a non-empty src to a guaranteed-large-enough dst. It
// assumes that the varint-encoded length of the decompressed bytes has already
// been written.
//
// It also assumes that:
//
// len(dst) >= MaxEncodedLen(len(src))
func encodeBlockBetter(dst, src []byte) (d int) {
if len(src) <= 64<<10 {
return encodeBlockBetterGo64K(dst, src)
}
return encodeBlockBetterGo(dst, src)
}
// encodeBlockBetter encodes a non-empty src to a guaranteed-large-enough dst. It
// assumes that the varint-encoded length of the decompressed bytes has already
// been written.
//
// It also assumes that:
//
// len(dst) >= MaxEncodedLen(len(src))
func encodeBlockBetterSnappy(dst, src []byte) (d int) {
if len(src) <= 64<<10 {
return encodeBlockBetterSnappyGo64K(dst, src)
}
return encodeBlockBetterSnappyGo(dst, src)
}
// encodeBlock encodes a non-empty src to a guaranteed-large-enough dst. It
// assumes that the varint-encoded length of the decompressed bytes has already
// been written.
//
// It also assumes that:
//
// len(dst) >= MaxEncodedLen(len(src))
func encodeBlockSnappy(dst, src []byte) (d int) {
if len(src) < minNonLiteralBlockSize {
return 0
}
if len(src) <= 64<<10 {
return encodeBlockSnappyGo64K(dst, src)
}
return encodeBlockSnappyGo(dst, src)
}
// emitLiteral writes a literal chunk and returns the number of bytes written.
//
// It assumes that:
//
// dst is long enough to hold the encoded bytes
// 0 <= len(lit) && len(lit) <= math.MaxUint32
func emitLiteral(dst, lit []byte) int {
if len(lit) == 0 {
return 0
}
const num = 63<<2 | tagLiteral
i, n := 0, uint(len(lit)-1)
switch {
case n < 60:
dst[0] = uint8(n)<<2 | tagLiteral
i = 1
case n < 1<<8:
dst[1] = uint8(n)
dst[0] = 60<<2 | tagLiteral
i = 2
case n < 1<<16:
dst[2] = uint8(n >> 8)
dst[1] = uint8(n)
dst[0] = 61<<2 | tagLiteral
i = 3
case n < 1<<24:
dst[3] = uint8(n >> 16)
dst[2] = uint8(n >> 8)
dst[1] = uint8(n)
dst[0] = 62<<2 | tagLiteral
i = 4
default:
dst[4] = uint8(n >> 24)
dst[3] = uint8(n >> 16)
dst[2] = uint8(n >> 8)
dst[1] = uint8(n)
dst[0] = 63<<2 | tagLiteral
i = 5
}
return i + copy(dst[i:], lit)
}
// emitRepeat writes a repeat chunk and returns the number of bytes written.
// Length must be at least 4 and < 1<<24
func emitRepeat(dst []byte, offset, length int) int {
// Repeat offset, make length cheaper
length -= 4
if length <= 4 {
dst[0] = uint8(length)<<2 | tagCopy1
dst[1] = 0
return 2
}
if length < 8 && offset < 2048 {
// Encode WITH offset
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length)<<2 | tagCopy1
return 2
}
if length < (1<<8)+4 {
length -= 4
dst[2] = uint8(length)
dst[1] = 0
dst[0] = 5<<2 | tagCopy1
return 3
}
if length < (1<<16)+(1<<8) {
length -= 1 << 8
dst[3] = uint8(length >> 8)
dst[2] = uint8(length >> 0)
dst[1] = 0
dst[0] = 6<<2 | tagCopy1
return 4
}
const maxRepeat = (1 << 24) - 1
length -= 1 << 16
left := 0
if length > maxRepeat {
left = length - maxRepeat + 4
length = maxRepeat - 4
}
dst[4] = uint8(length >> 16)
dst[3] = uint8(length >> 8)
dst[2] = uint8(length >> 0)
dst[1] = 0
dst[0] = 7<<2 | tagCopy1
if left > 0 {
return 5 + emitRepeat(dst[5:], offset, left)
}
return 5
}
// emitCopy writes a copy chunk and returns the number of bytes written.
//
// It assumes that:
//
// dst is long enough to hold the encoded bytes
// 1 <= offset && offset <= math.MaxUint32
// 4 <= length && length <= 1 << 24
func emitCopy(dst []byte, offset, length int) int {
if offset >= 65536 {
i := 0
if length > 64 {
// Emit a length 64 copy, encoded as 5 bytes.
dst[4] = uint8(offset >> 24)
dst[3] = uint8(offset >> 16)
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = 63<<2 | tagCopy4
length -= 64
if length >= 4 {
// Emit remaining as repeats
return 5 + emitRepeat(dst[5:], offset, length)
}
i = 5
}
if length == 0 {
return i
}
// Emit a copy, offset encoded as 4 bytes.
dst[i+0] = uint8(length-1)<<2 | tagCopy4
dst[i+1] = uint8(offset)
dst[i+2] = uint8(offset >> 8)
dst[i+3] = uint8(offset >> 16)
dst[i+4] = uint8(offset >> 24)
return i + 5
}
// Offset no more than 2 bytes.
if length > 64 {
off := 3
if offset < 2048 {
// emit 8 bytes as tagCopy1, rest as repeats.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(8-4)<<2 | tagCopy1
length -= 8
off = 2
} else {
// Emit a length 60 copy, encoded as 3 bytes.
// Emit remaining as repeat value (minimum 4 bytes).
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = 59<<2 | tagCopy2
length -= 60
}
// Emit remaining as repeats, at least 4 bytes remain.
return off + emitRepeat(dst[off:], offset, length)
}
if length >= 12 || offset >= 2048 {
// Emit the remaining copy, encoded as 3 bytes.
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = uint8(length-1)<<2 | tagCopy2
return 3
}
// Emit the remaining copy, encoded as 2 bytes.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
return 2
}
// emitCopyNoRepeat writes a copy chunk and returns the number of bytes written.
//
// It assumes that:
//
// dst is long enough to hold the encoded bytes
// 1 <= offset && offset <= math.MaxUint32
// 4 <= length && length <= 1 << 24
func emitCopyNoRepeat(dst []byte, offset, length int) int {
if offset >= 65536 {
i := 0
if length > 64 {
// Emit a length 64 copy, encoded as 5 bytes.
dst[4] = uint8(offset >> 24)
dst[3] = uint8(offset >> 16)
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = 63<<2 | tagCopy4
length -= 64
if length >= 4 {
// Emit remaining as repeats
return 5 + emitCopyNoRepeat(dst[5:], offset, length)
}
i = 5
}
if length == 0 {
return i
}
// Emit a copy, offset encoded as 4 bytes.
dst[i+0] = uint8(length-1)<<2 | tagCopy4
dst[i+1] = uint8(offset)
dst[i+2] = uint8(offset >> 8)
dst[i+3] = uint8(offset >> 16)
dst[i+4] = uint8(offset >> 24)
return i + 5
}
// Offset no more than 2 bytes.
if length > 64 {
// Emit a length 60 copy, encoded as 3 bytes.
// Emit remaining as repeat value (minimum 4 bytes).
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = 59<<2 | tagCopy2
length -= 60
// Emit remaining as repeats, at least 4 bytes remain.
return 3 + emitCopyNoRepeat(dst[3:], offset, length)
}
if length >= 12 || offset >= 2048 {
// Emit the remaining copy, encoded as 3 bytes.
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = uint8(length-1)<<2 | tagCopy2
return 3
}
// Emit the remaining copy, encoded as 2 bytes.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
return 2
}
// matchLen returns how many bytes match in a and b
//
// It assumes that:
//
// len(a) <= len(b)
func matchLen(a []byte, b []byte) int {
b = b[:len(a)]
var checked int
if len(a) > 4 {
// Try 4 bytes first
if diff := load32(a, 0) ^ load32(b, 0); diff != 0 {
return bits.TrailingZeros32(diff) >> 3
}
// Switch to 8 byte matching.
checked = 4
a = a[4:]
b = b[4:]
for len(a) >= 8 {
b = b[:len(a)]
if diff := load64(a, 0) ^ load64(b, 0); diff != 0 {
return checked + (bits.TrailingZeros64(diff) >> 3)
}
checked += 8
a = a[8:]
b = b[8:]
}
}
b = b[:len(a)]
for i := range a {
if a[i] != b[i] {
return int(i) + checked
}
}
return len(a) + checked
}
// input must be > inputMargin
func calcBlockSize(src []byte, _ *[32768]byte) (d int) {
// Initialize the hash table.
const (
tableBits = 13
maxTableSize = 1 << tableBits
)
var table [maxTableSize]uint32
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := len(src) - inputMargin
// Bail if we can't compress to at least this.
dstLimit := len(src) - len(src)>>5 - 5
// nextEmit is where in src the next emitLiteral should start from.
nextEmit := 0
// The encoded form must start with a literal, as there are no previous
// bytes to copy, so we start looking for hash matches at s == 1.
s := 1
cv := load64(src, s)
// We search for a repeat at -1, but don't output repeats when nextEmit == 0
repeat := 1
for {
candidate := 0
for {
// Next src position to check
nextS := s + (s-nextEmit)>>6 + 4
if nextS > sLimit {
goto emitRemainder
}
hash0 := hash6(cv, tableBits)
hash1 := hash6(cv>>8, tableBits)
candidate = int(table[hash0])
candidate2 := int(table[hash1])
table[hash0] = uint32(s)
table[hash1] = uint32(s + 1)
hash2 := hash6(cv>>16, tableBits)
// Check repeat at offset checkRep.
const checkRep = 1
if uint32(cv>>(checkRep*8)) == load32(src, s-repeat+checkRep) {
base := s + checkRep
// Extend back
for i := base - repeat; base > nextEmit && i > 0 && src[i-1] == src[base-1]; {
i--
base--
}
d += emitLiteralSize(src[nextEmit:base])
// Extend forward
candidate := s - repeat + 4 + checkRep
s += 4 + checkRep
for s <= sLimit {
if diff := load64(src, s) ^ load64(src, candidate); diff != 0 {
s += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
candidate += 8
}
d += emitCopyNoRepeatSize(repeat, s-base)
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
cv = load64(src, s)
continue
}
if uint32(cv) == load32(src, candidate) {
break
}
candidate = int(table[hash2])
if uint32(cv>>8) == load32(src, candidate2) {
table[hash2] = uint32(s + 2)
candidate = candidate2
s++
break
}
table[hash2] = uint32(s + 2)
if uint32(cv>>16) == load32(src, candidate) {
s += 2
break
}
cv = load64(src, nextS)
s = nextS
}
// Extend backwards
for candidate > 0 && s > nextEmit && src[candidate-1] == src[s-1] {
candidate--
s--
}
// Bail if we exceed the maximum size.
if d+(s-nextEmit) > dstLimit {
return 0
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
d += emitLiteralSize(src[nextEmit:s])
// Call emitCopy, and then see if another emitCopy could be our next
// move. Repeat until we find no match for the input immediately after
// what was consumed by the last emitCopy call.
//
// If we exit this loop normally then we need to call emitLiteral next,
// though we don't yet know how big the literal will be. We handle that
// by proceeding to the next iteration of the main loop. We also can
// exit this loop via goto if we get close to exhausting the input.
for {
// Invariant: we have a 4-byte match at s, and no need to emit any
// literal bytes prior to s.
base := s
repeat = base - candidate
// Extend the 4-byte match as long as possible.
s += 4
candidate += 4
for s <= len(src)-8 {
if diff := load64(src, s) ^ load64(src, candidate); diff != 0 {
s += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
candidate += 8
}
d += emitCopyNoRepeatSize(repeat, s-base)
if false {
// Validate match.
a := src[base:s]
b := src[base-repeat : base-repeat+(s-base)]
if !bytes.Equal(a, b) {
panic("mismatch")
}
}
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
if d > dstLimit {
// Do we have space for more, if not bail.
return 0
}
// Check for an immediate match, otherwise start search at s+1
x := load64(src, s-2)
m2Hash := hash6(x, tableBits)
currHash := hash6(x>>16, tableBits)
candidate = int(table[currHash])
table[m2Hash] = uint32(s - 2)
table[currHash] = uint32(s)
if uint32(x>>16) != load32(src, candidate) {
cv = load64(src, s+1)
s++
break
}
}
}
emitRemainder:
if nextEmit < len(src) {
// Bail if we exceed the maximum size.
if d+len(src)-nextEmit > dstLimit {
return 0
}
d += emitLiteralSize(src[nextEmit:])
}
return d
}
// length must be > inputMargin.
func calcBlockSizeSmall(src []byte, _ *[2048]byte) (d int) {
// Initialize the hash table.
const (
tableBits = 9
maxTableSize = 1 << tableBits
)
var table [maxTableSize]uint32
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := len(src) - inputMargin
// Bail if we can't compress to at least this.
dstLimit := len(src) - len(src)>>5 - 5
// nextEmit is where in src the next emitLiteral should start from.
nextEmit := 0
// The encoded form must start with a literal, as there are no previous
// bytes to copy, so we start looking for hash matches at s == 1.
s := 1
cv := load64(src, s)
// We search for a repeat at -1, but don't output repeats when nextEmit == 0
repeat := 1
for {
candidate := 0
for {
// Next src position to check
nextS := s + (s-nextEmit)>>6 + 4
if nextS > sLimit {
goto emitRemainder
}
hash0 := hash6(cv, tableBits)
hash1 := hash6(cv>>8, tableBits)
candidate = int(table[hash0])
candidate2 := int(table[hash1])
table[hash0] = uint32(s)
table[hash1] = uint32(s + 1)
hash2 := hash6(cv>>16, tableBits)
// Check repeat at offset checkRep.
const checkRep = 1
if uint32(cv>>(checkRep*8)) == load32(src, s-repeat+checkRep) {
base := s + checkRep
// Extend back
for i := base - repeat; base > nextEmit && i > 0 && src[i-1] == src[base-1]; {
i--
base--
}
d += emitLiteralSize(src[nextEmit:base])
// Extend forward
candidate := s - repeat + 4 + checkRep
s += 4 + checkRep
for s <= sLimit {
if diff := load64(src, s) ^ load64(src, candidate); diff != 0 {
s += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
candidate += 8
}
d += emitCopyNoRepeatSize(repeat, s-base)
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
cv = load64(src, s)
continue
}
if uint32(cv) == load32(src, candidate) {
break
}
candidate = int(table[hash2])
if uint32(cv>>8) == load32(src, candidate2) {
table[hash2] = uint32(s + 2)
candidate = candidate2
s++
break
}
table[hash2] = uint32(s + 2)
if uint32(cv>>16) == load32(src, candidate) {
s += 2
break
}
cv = load64(src, nextS)
s = nextS
}
// Extend backwards
for candidate > 0 && s > nextEmit && src[candidate-1] == src[s-1] {
candidate--
s--
}
// Bail if we exceed the maximum size.
if d+(s-nextEmit) > dstLimit {
return 0
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
d += emitLiteralSize(src[nextEmit:s])
// Call emitCopy, and then see if another emitCopy could be our next
// move. Repeat until we find no match for the input immediately after
// what was consumed by the last emitCopy call.
//
// If we exit this loop normally then we need to call emitLiteral next,
// though we don't yet know how big the literal will be. We handle that
// by proceeding to the next iteration of the main loop. We also can
// exit this loop via goto if we get close to exhausting the input.
for {
// Invariant: we have a 4-byte match at s, and no need to emit any
// literal bytes prior to s.
base := s
repeat = base - candidate
// Extend the 4-byte match as long as possible.
s += 4
candidate += 4
for s <= len(src)-8 {
if diff := load64(src, s) ^ load64(src, candidate); diff != 0 {
s += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
candidate += 8
}
d += emitCopyNoRepeatSize(repeat, s-base)
if false {
// Validate match.
a := src[base:s]
b := src[base-repeat : base-repeat+(s-base)]
if !bytes.Equal(a, b) {
panic("mismatch")
}
}
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
if d > dstLimit {
// Do we have space for more, if not bail.
return 0
}
// Check for an immediate match, otherwise start search at s+1
x := load64(src, s-2)
m2Hash := hash6(x, tableBits)
currHash := hash6(x>>16, tableBits)
candidate = int(table[currHash])
table[m2Hash] = uint32(s - 2)
table[currHash] = uint32(s)
if uint32(x>>16) != load32(src, candidate) {
cv = load64(src, s+1)
s++
break
}
}
}
emitRemainder:
if nextEmit < len(src) {
// Bail if we exceed the maximum size.
if d+len(src)-nextEmit > dstLimit {
return 0
}
d += emitLiteralSize(src[nextEmit:])
}
return d
}
// emitLiteral writes a literal chunk and returns the number of bytes written.
//
// It assumes that:
//
// dst is long enough to hold the encoded bytes
// 0 <= len(lit) && len(lit) <= math.MaxUint32
func emitLiteralSize(lit []byte) int {
if len(lit) == 0 {
return 0
}
switch {
case len(lit) <= 60:
return len(lit) + 1
case len(lit) <= 1<<8:
return len(lit) + 2
case len(lit) <= 1<<16:
return len(lit) + 3
case len(lit) <= 1<<24:
return len(lit) + 4
default:
return len(lit) + 5
}
}
func cvtLZ4BlockAsm(dst []byte, src []byte) (uncompressed int, dstUsed int) {
panic("cvtLZ4BlockAsm should be unreachable")
}
func cvtLZ4BlockSnappyAsm(dst []byte, src []byte) (uncompressed int, dstUsed int) {
panic("cvtLZ4BlockSnappyAsm should be unreachable")
}
func cvtLZ4sBlockAsm(dst []byte, src []byte) (uncompressed int, dstUsed int) {
panic("cvtLZ4sBlockAsm should be unreachable")
}
func cvtLZ4sBlockSnappyAsm(dst []byte, src []byte) (uncompressed int, dstUsed int) {
panic("cvtLZ4sBlockSnappyAsm should be unreachable")
}
Server/vendor/github.com/klauspost/compress/s2/encodeblock_amd64.go
Generated Vendored
+228
View File
@@ -0,0 +1,228 @@
// Code generated by command: go run gen.go -out ../encodeblock_amd64.s -stubs ../encodeblock_amd64.go -pkg=s2. DO NOT EDIT.
//go:build !appengine && !noasm && gc && !noasm
package s2
func _dummy_()
// encodeBlockAsm encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4294967295 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBlockAsm(dst []byte, src []byte, tmp *[65536]byte) int
// encodeBlockAsm4MB encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4194304 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBlockAsm4MB(dst []byte, src []byte, tmp *[65536]byte) int
// encodeBlockAsm12B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 16383 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBlockAsm12B(dst []byte, src []byte, tmp *[16384]byte) int
// encodeBlockAsm10B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4095 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBlockAsm10B(dst []byte, src []byte, tmp *[4096]byte) int
// encodeBlockAsm8B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 511 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBlockAsm8B(dst []byte, src []byte, tmp *[1024]byte) int
// encodeBetterBlockAsm encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4294967295 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBetterBlockAsm(dst []byte, src []byte, tmp *[589824]byte) int
// encodeBetterBlockAsm4MB encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4194304 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBetterBlockAsm4MB(dst []byte, src []byte, tmp *[589824]byte) int
// encodeBetterBlockAsm12B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 16383 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBetterBlockAsm12B(dst []byte, src []byte, tmp *[81920]byte) int
// encodeBetterBlockAsm10B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4095 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBetterBlockAsm10B(dst []byte, src []byte, tmp *[20480]byte) int
// encodeBetterBlockAsm8B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 511 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBetterBlockAsm8B(dst []byte, src []byte, tmp *[5120]byte) int
// encodeSnappyBlockAsm encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4294967295 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBlockAsm(dst []byte, src []byte, tmp *[65536]byte) int
// encodeSnappyBlockAsm64K encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 65535 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBlockAsm64K(dst []byte, src []byte, tmp *[65536]byte) int
// encodeSnappyBlockAsm12B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 16383 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBlockAsm12B(dst []byte, src []byte, tmp *[16384]byte) int
// encodeSnappyBlockAsm10B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4095 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBlockAsm10B(dst []byte, src []byte, tmp *[4096]byte) int
// encodeSnappyBlockAsm8B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 511 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBlockAsm8B(dst []byte, src []byte, tmp *[1024]byte) int
// encodeSnappyBetterBlockAsm encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4294967295 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBetterBlockAsm(dst []byte, src []byte, tmp *[589824]byte) int
// encodeSnappyBetterBlockAsm64K encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 65535 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBetterBlockAsm64K(dst []byte, src []byte, tmp *[294912]byte) int
// encodeSnappyBetterBlockAsm12B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 16383 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBetterBlockAsm12B(dst []byte, src []byte, tmp *[81920]byte) int
// encodeSnappyBetterBlockAsm10B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4095 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBetterBlockAsm10B(dst []byte, src []byte, tmp *[20480]byte) int
// encodeSnappyBetterBlockAsm8B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 511 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBetterBlockAsm8B(dst []byte, src []byte, tmp *[5120]byte) int
// calcBlockSize encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4294967295 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func calcBlockSize(src []byte, tmp *[32768]byte) int
// calcBlockSizeSmall encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 1024 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func calcBlockSizeSmall(src []byte, tmp *[2048]byte) int
// emitLiteral writes a literal chunk and returns the number of bytes written.
//
// It assumes that:
//
// dst is long enough to hold the encoded bytes with margin of 0 bytes
// 0 <= len(lit) && len(lit) <= math.MaxUint32
//
//go:noescape
func emitLiteral(dst []byte, lit []byte) int
// emitRepeat writes a repeat chunk and returns the number of bytes written.
// Length must be at least 4 and < 1<<32
//
//go:noescape
func emitRepeat(dst []byte, offset int, length int) int
// emitCopy writes a copy chunk and returns the number of bytes written.
//
// It assumes that:
//
// dst is long enough to hold the encoded bytes
// 1 <= offset && offset <= math.MaxUint32
// 4 <= length && length <= 1 << 24
//
//go:noescape
func emitCopy(dst []byte, offset int, length int) int
// emitCopyNoRepeat writes a copy chunk and returns the number of bytes written.
//
// It assumes that:
//
// dst is long enough to hold the encoded bytes
// 1 <= offset && offset <= math.MaxUint32
// 4 <= length && length <= 1 << 24
//
//go:noescape
func emitCopyNoRepeat(dst []byte, offset int, length int) int
// matchLen returns how many bytes match in a and b
//
// It assumes that:
//
// len(a) <= len(b)
//
//go:noescape
func matchLen(a []byte, b []byte) int
// cvtLZ4Block converts an LZ4 block to S2
//
//go:noescape
func cvtLZ4BlockAsm(dst []byte, src []byte) (uncompressed int, dstUsed int)
// cvtLZ4sBlock converts an LZ4s block to S2
//
//go:noescape
func cvtLZ4sBlockAsm(dst []byte, src []byte) (uncompressed int, dstUsed int)
// cvtLZ4Block converts an LZ4 block to Snappy
//
//go:noescape
func cvtLZ4BlockSnappyAsm(dst []byte, src []byte) (uncompressed int, dstUsed int)
// cvtLZ4sBlock converts an LZ4s block to Snappy
//
//go:noescape
func cvtLZ4sBlockSnappyAsm(dst []byte, src []byte) (uncompressed int, dstUsed int)
Server/vendor/github.com/klauspost/compress/s2/encodeblock_amd64.s
Generated Vendored
+21303
View File
File diff suppressed because it is too large Load Diff
Server/vendor/github.com/klauspost/compress/s2/index.go
Generated Vendored
+602
View File
@@ -0,0 +1,602 @@
// Copyright (c) 2022+ Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package s2
import (
"bytes"
"encoding/binary"
"encoding/json"
"fmt"
"io"
"sort"
)
const (
S2IndexHeader = "s2idx\x00"
S2IndexTrailer = "\x00xdi2s"
maxIndexEntries = 1 << 16
// If distance is less than this, we do not add the entry.
minIndexDist = 1 << 20
)
// Index represents an S2/Snappy index.
type Index struct {
TotalUncompressed int64 // Total Uncompressed size if known. Will be -1 if unknown.
TotalCompressed int64 // Total Compressed size if known. Will be -1 if unknown.
info []struct {
compressedOffset int64
uncompressedOffset int64
}
estBlockUncomp int64
}
func (i *Index) reset(maxBlock int) {
i.estBlockUncomp = int64(maxBlock)
i.TotalCompressed = -1
i.TotalUncompressed = -1
if len(i.info) > 0 {
i.info = i.info[:0]
}
}
// allocInfos will allocate an empty slice of infos.
func (i *Index) allocInfos(n int) {
if n > maxIndexEntries {
panic("n > maxIndexEntries")
}
i.info = make([]struct {
compressedOffset int64
uncompressedOffset int64
}, 0, n)
}
// add an uncompressed and compressed pair.
// Entries must be sent in order.
func (i *Index) add(compressedOffset, uncompressedOffset int64) error {
if i == nil {
return nil
}
lastIdx := len(i.info) - 1
if lastIdx >= 0 {
latest := i.info[lastIdx]
if latest.uncompressedOffset == uncompressedOffset {
// Uncompressed didn't change, don't add entry,
// but update start index.
latest.compressedOffset = compressedOffset
i.info[lastIdx] = latest
return nil
}
if latest.uncompressedOffset > uncompressedOffset {
return fmt.Errorf("internal error: Earlier uncompressed received (%d > %d)", latest.uncompressedOffset, uncompressedOffset)
}
if latest.compressedOffset > compressedOffset {
return fmt.Errorf("internal error: Earlier compressed received (%d > %d)", latest.compressedOffset, compressedOffset)
}
if latest.uncompressedOffset+minIndexDist > uncompressedOffset {
// Only add entry if distance is large enough.
return nil
}
}
i.info = append(i.info, struct {
compressedOffset int64
uncompressedOffset int64
}{compressedOffset: compressedOffset, uncompressedOffset: uncompressedOffset})
return nil
}
// Find the offset at or before the wanted (uncompressed) offset.
// If offset is 0 or positive it is the offset from the beginning of the file.
// If the uncompressed size is known, the offset must be within the file.
// If an offset outside the file is requested io.ErrUnexpectedEOF is returned.
// If the offset is negative, it is interpreted as the distance from the end of the file,
// where -1 represents the last byte.
// If offset from the end of the file is requested, but size is unknown,
// ErrUnsupported will be returned.
func (i *Index) Find(offset int64) (compressedOff, uncompressedOff int64, err error) {
if i.TotalUncompressed < 0 {
return 0, 0, ErrCorrupt
}
if offset < 0 {
offset = i.TotalUncompressed + offset
if offset < 0 {
return 0, 0, io.ErrUnexpectedEOF
}
}
if offset > i.TotalUncompressed {
return 0, 0, io.ErrUnexpectedEOF
}
if len(i.info) > 200 {
n := sort.Search(len(i.info), func(n int) bool {
return i.info[n].uncompressedOffset > offset
})
if n == 0 {
n = 1
}
return i.info[n-1].compressedOffset, i.info[n-1].uncompressedOffset, nil
}
for _, info := range i.info {
if info.uncompressedOffset > offset {
break
}
compressedOff = info.compressedOffset
uncompressedOff = info.uncompressedOffset
}
return compressedOff, uncompressedOff, nil
}
// reduce to stay below maxIndexEntries
func (i *Index) reduce() {
if len(i.info) < maxIndexEntries && i.estBlockUncomp >= minIndexDist {
return
}
// Algorithm, keep 1, remove removeN entries...
removeN := (len(i.info) + 1) / maxIndexEntries
src := i.info
j := 0
// Each block should be at least 1MB, but don't reduce below 1000 entries.
for i.estBlockUncomp*(int64(removeN)+1) < minIndexDist && len(i.info)/(removeN+1) > 1000 {
removeN++
}
for idx := 0; idx < len(src); idx++ {
i.info[j] = src[idx]
j++
idx += removeN
}
i.info = i.info[:j]
// Update maxblock estimate.
i.estBlockUncomp += i.estBlockUncomp * int64(removeN)
}
func (i *Index) appendTo(b []byte, uncompTotal, compTotal int64) []byte {
i.reduce()
var tmp [binary.MaxVarintLen64]byte
initSize := len(b)
// We make the start a skippable header+size.
b = append(b, ChunkTypeIndex, 0, 0, 0)
b = append(b, []byte(S2IndexHeader)...)
// Total Uncompressed size
n := binary.PutVarint(tmp[:], uncompTotal)
b = append(b, tmp[:n]...)
// Total Compressed size
n = binary.PutVarint(tmp[:], compTotal)
b = append(b, tmp[:n]...)
// Put EstBlockUncomp size
n = binary.PutVarint(tmp[:], i.estBlockUncomp)
b = append(b, tmp[:n]...)
// Put length
n = binary.PutVarint(tmp[:], int64(len(i.info)))
b = append(b, tmp[:n]...)
// Check if we should add uncompressed offsets
var hasUncompressed byte
for idx, info := range i.info {
if idx == 0 {
if info.uncompressedOffset != 0 {
hasUncompressed = 1
break
}
continue
}
if info.uncompressedOffset != i.info[idx-1].uncompressedOffset+i.estBlockUncomp {
hasUncompressed = 1
break
}
}
b = append(b, hasUncompressed)
// Add each entry
if hasUncompressed == 1 {
for idx, info := range i.info {
uOff := info.uncompressedOffset
if idx > 0 {
prev := i.info[idx-1]
uOff -= prev.uncompressedOffset + (i.estBlockUncomp)
}
n = binary.PutVarint(tmp[:], uOff)
b = append(b, tmp[:n]...)
}
}
// Initial compressed size estimate.
cPredict := i.estBlockUncomp / 2
for idx, info := range i.info {
cOff := info.compressedOffset
if idx > 0 {
prev := i.info[idx-1]
cOff -= prev.compressedOffset + cPredict
// Update compressed size prediction, with half the error.
cPredict += cOff / 2
}
n = binary.PutVarint(tmp[:], cOff)
b = append(b, tmp[:n]...)
}
// Add Total Size.
// Stored as fixed size for easier reading.
binary.LittleEndian.PutUint32(tmp[:], uint32(len(b)-initSize+4+len(S2IndexTrailer)))
b = append(b, tmp[:4]...)
// Trailer
b = append(b, []byte(S2IndexTrailer)...)
// Update size
chunkLen := len(b) - initSize - skippableFrameHeader
b[initSize+1] = uint8(chunkLen >> 0)
b[initSize+2] = uint8(chunkLen >> 8)
b[initSize+3] = uint8(chunkLen >> 16)
//fmt.Printf("chunklen: 0x%x Uncomp:%d, Comp:%d\n", chunkLen, uncompTotal, compTotal)
return b
}
// Load a binary index.
// A zero value Index can be used or a previous one can be reused.
func (i *Index) Load(b []byte) ([]byte, error) {
if len(b) <= 4+len(S2IndexHeader)+len(S2IndexTrailer) {
return b, io.ErrUnexpectedEOF
}
if b[0] != ChunkTypeIndex {
return b, ErrCorrupt
}
chunkLen := int(b[1]) | int(b[2])<<8 | int(b[3])<<16
b = b[4:]
// Validate we have enough...
if len(b) < chunkLen {
return b, io.ErrUnexpectedEOF
}
if !bytes.Equal(b[:len(S2IndexHeader)], []byte(S2IndexHeader)) {
return b, ErrUnsupported
}
b = b[len(S2IndexHeader):]
// Total Uncompressed
if v, n := binary.Varint(b); n <= 0 || v < 0 {
return b, ErrCorrupt
} else {
i.TotalUncompressed = v
b = b[n:]
}
// Total Compressed
if v, n := binary.Varint(b); n <= 0 {
return b, ErrCorrupt
} else {
i.TotalCompressed = v
b = b[n:]
}
// Read EstBlockUncomp
if v, n := binary.Varint(b); n <= 0 {
return b, ErrCorrupt
} else {
if v < 0 {
return b, ErrCorrupt
}
i.estBlockUncomp = v
b = b[n:]
}
var entries int
if v, n := binary.Varint(b); n <= 0 {
return b, ErrCorrupt
} else {
if v < 0 || v > maxIndexEntries {
return b, ErrCorrupt
}
entries = int(v)
b = b[n:]
}
if cap(i.info) < entries {
i.allocInfos(entries)
}
i.info = i.info[:entries]
if len(b) < 1 {
return b, io.ErrUnexpectedEOF
}
hasUncompressed := b[0]
b = b[1:]
if hasUncompressed&1 != hasUncompressed {
return b, ErrCorrupt
}
// Add each uncompressed entry
for idx := range i.info {
var uOff int64
if hasUncompressed != 0 {
// Load delta
if v, n := binary.Varint(b); n <= 0 {
return b, ErrCorrupt
} else {
uOff = v
b = b[n:]
}
}
if idx > 0 {
prev := i.info[idx-1].uncompressedOffset
uOff += prev + (i.estBlockUncomp)
if uOff <= prev {
return b, ErrCorrupt
}
}
if uOff < 0 {
return b, ErrCorrupt
}
i.info[idx].uncompressedOffset = uOff
}
// Initial compressed size estimate.
cPredict := i.estBlockUncomp / 2
// Add each compressed entry
for idx := range i.info {
var cOff int64
if v, n := binary.Varint(b); n <= 0 {
return b, ErrCorrupt
} else {
cOff = v
b = b[n:]
}
if idx > 0 {
// Update compressed size prediction, with half the error.
cPredictNew := cPredict + cOff/2
prev := i.info[idx-1].compressedOffset
cOff += prev + cPredict
if cOff <= prev {
return b, ErrCorrupt
}
cPredict = cPredictNew
}
if cOff < 0 {
return b, ErrCorrupt
}
i.info[idx].compressedOffset = cOff
}
if len(b) < 4+len(S2IndexTrailer) {
return b, io.ErrUnexpectedEOF
}
// Skip size...
b = b[4:]
// Check trailer...
if !bytes.Equal(b[:len(S2IndexTrailer)], []byte(S2IndexTrailer)) {
return b, ErrCorrupt
}
return b[len(S2IndexTrailer):], nil
}
// LoadStream will load an index from the end of the supplied stream.
// ErrUnsupported will be returned if the signature cannot be found.
// ErrCorrupt will be returned if unexpected values are found.
// io.ErrUnexpectedEOF is returned if there are too few bytes.
// IO errors are returned as-is.
func (i *Index) LoadStream(rs io.ReadSeeker) error {
// Go to end.
_, err := rs.Seek(-10, io.SeekEnd)
if err != nil {
return err
}
var tmp [10]byte
_, err = io.ReadFull(rs, tmp[:])
if err != nil {
return err
}
// Check trailer...
if !bytes.Equal(tmp[4:4+len(S2IndexTrailer)], []byte(S2IndexTrailer)) {
return ErrUnsupported
}
sz := binary.LittleEndian.Uint32(tmp[:4])
if sz > maxChunkSize+skippableFrameHeader {
return ErrCorrupt
}
_, err = rs.Seek(-int64(sz), io.SeekEnd)
if err != nil {
return err
}
// Read index.
buf := make([]byte, sz)
_, err = io.ReadFull(rs, buf)
if err != nil {
return err
}
_, err = i.Load(buf)
return err
}
// IndexStream will return an index for a stream.
// The stream structure will be checked, but
// data within blocks is not verified.
// The returned index can either be appended to the end of the stream
// or stored separately.
func IndexStream(r io.Reader) ([]byte, error) {
var i Index
var buf [maxChunkSize]byte
var readHeader bool
for {
_, err := io.ReadFull(r, buf[:4])
if err != nil {
if err == io.EOF {
return i.appendTo(nil, i.TotalUncompressed, i.TotalCompressed), nil
}
return nil, err
}
// Start of this chunk.
startChunk := i.TotalCompressed
i.TotalCompressed += 4
chunkType := buf[0]
if !readHeader {
if chunkType != chunkTypeStreamIdentifier {
return nil, ErrCorrupt
}
readHeader = true
}
chunkLen := int(buf[1]) | int(buf[2])<<8 | int(buf[3])<<16
if chunkLen < checksumSize {
return nil, ErrCorrupt
}
i.TotalCompressed += int64(chunkLen)
_, err = io.ReadFull(r, buf[:chunkLen])
if err != nil {
return nil, io.ErrUnexpectedEOF
}
// The chunk types are specified at
// https://github.com/google/snappy/blob/master/framing_format.txt
switch chunkType {
case chunkTypeCompressedData:
// Section 4.2. Compressed data (chunk type 0x00).
// Skip checksum.
dLen, err := DecodedLen(buf[checksumSize:])
if err != nil {
return nil, err
}
if dLen > maxBlockSize {
return nil, ErrCorrupt
}
if i.estBlockUncomp == 0 {
// Use first block for estimate...
i.estBlockUncomp = int64(dLen)
}
err = i.add(startChunk, i.TotalUncompressed)
if err != nil {
return nil, err
}
i.TotalUncompressed += int64(dLen)
continue
case chunkTypeUncompressedData:
n2 := chunkLen - checksumSize
if n2 > maxBlockSize {
return nil, ErrCorrupt
}
if i.estBlockUncomp == 0 {
// Use first block for estimate...
i.estBlockUncomp = int64(n2)
}
err = i.add(startChunk, i.TotalUncompressed)
if err != nil {
return nil, err
}
i.TotalUncompressed += int64(n2)
continue
case chunkTypeStreamIdentifier:
// Section 4.1. Stream identifier (chunk type 0xff).
if chunkLen != len(magicBody) {
return nil, ErrCorrupt
}
if string(buf[:len(magicBody)]) != magicBody {
if string(buf[:len(magicBody)]) != magicBodySnappy {
return nil, ErrCorrupt
}
}
continue
}
if chunkType <= 0x7f {
// Section 4.5. Reserved unskippable chunks (chunk types 0x02-0x7f).
return nil, ErrUnsupported
}
if chunkLen > maxChunkSize {
return nil, ErrUnsupported
}
// Section 4.4 Padding (chunk type 0xfe).
// Section 4.6. Reserved skippable chunks (chunk types 0x80-0xfd).
}
}
// JSON returns the index as JSON text.
func (i *Index) JSON() []byte {
type offset struct {
CompressedOffset int64 `json:"compressed"`
UncompressedOffset int64 `json:"uncompressed"`
}
x := struct {
TotalUncompressed int64 `json:"total_uncompressed"` // Total Uncompressed size if known. Will be -1 if unknown.
TotalCompressed int64 `json:"total_compressed"` // Total Compressed size if known. Will be -1 if unknown.
Offsets []offset `json:"offsets"`
EstBlockUncomp int64 `json:"est_block_uncompressed"`
}{
TotalUncompressed: i.TotalUncompressed,
TotalCompressed: i.TotalCompressed,
EstBlockUncomp: i.estBlockUncomp,
}
for _, v := range i.info {
x.Offsets = append(x.Offsets, offset{CompressedOffset: v.compressedOffset, UncompressedOffset: v.uncompressedOffset})
}
b, _ := json.MarshalIndent(x, "", " ")
return b
}
// RemoveIndexHeaders will trim all headers and trailers from a given index.
// This is expected to save 20 bytes.
// These can be restored using RestoreIndexHeaders.
// This removes a layer of security, but is the most compact representation.
// Returns nil if headers contains errors.
// The returned slice references the provided slice.
func RemoveIndexHeaders(b []byte) []byte {
const save = 4 + len(S2IndexHeader) + len(S2IndexTrailer) + 4
if len(b) <= save {
return nil
}
if b[0] != ChunkTypeIndex {
return nil
}
chunkLen := int(b[1]) | int(b[2])<<8 | int(b[3])<<16
b = b[4:]
// Validate we have enough...
if len(b) < chunkLen {
return nil
}
b = b[:chunkLen]
if !bytes.Equal(b[:len(S2IndexHeader)], []byte(S2IndexHeader)) {
return nil
}
b = b[len(S2IndexHeader):]
if !bytes.HasSuffix(b, []byte(S2IndexTrailer)) {
return nil
}
b = bytes.TrimSuffix(b, []byte(S2IndexTrailer))
if len(b) < 4 {
return nil
}
return b[:len(b)-4]
}
// RestoreIndexHeaders will index restore headers removed by RemoveIndexHeaders.
// No error checking is performed on the input.
// If a 0 length slice is sent, it is returned without modification.
func RestoreIndexHeaders(in []byte) []byte {
if len(in) == 0 {
return in
}
b := make([]byte, 0, 4+len(S2IndexHeader)+len(in)+len(S2IndexTrailer)+4)
b = append(b, ChunkTypeIndex, 0, 0, 0)
b = append(b, []byte(S2IndexHeader)...)
b = append(b, in...)
var tmp [4]byte
binary.LittleEndian.PutUint32(tmp[:], uint32(len(b)+4+len(S2IndexTrailer)))
b = append(b, tmp[:4]...)
// Trailer
b = append(b, []byte(S2IndexTrailer)...)
chunkLen := len(b) - skippableFrameHeader
b[1] = uint8(chunkLen >> 0)
b[2] = uint8(chunkLen >> 8)
b[3] = uint8(chunkLen >> 16)
return b
}
Server/vendor/github.com/klauspost/compress/s2/lz4convert.go
Generated Vendored
+585
View File
@@ -0,0 +1,585 @@
// Copyright (c) 2022 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package s2
import (
"encoding/binary"
"errors"
"fmt"
)
// LZ4Converter provides conversion from LZ4 blocks as defined here:
// https://github.com/lz4/lz4/blob/dev/doc/lz4_Block_format.md
type LZ4Converter struct {
}
// ErrDstTooSmall is returned when provided destination is too small.
var ErrDstTooSmall = errors.New("s2: destination too small")
// ConvertBlock will convert an LZ4 block and append it as an S2
// block without block length to dst.
// The uncompressed size is returned as well.
// dst must have capacity to contain the entire compressed block.
func (l *LZ4Converter) ConvertBlock(dst, src []byte) ([]byte, int, error) {
if len(src) == 0 {
return dst, 0, nil
}
const debug = false
const inline = true
const lz4MinMatch = 4
s, d := 0, len(dst)
dst = dst[:cap(dst)]
if !debug && hasAmd64Asm {
res, sz := cvtLZ4BlockAsm(dst[d:], src)
if res < 0 {
const (
errCorrupt = -1
errDstTooSmall = -2
)
switch res {
case errCorrupt:
return nil, 0, ErrCorrupt
case errDstTooSmall:
return nil, 0, ErrDstTooSmall
default:
return nil, 0, fmt.Errorf("unexpected result: %d", res)
}
}
if d+sz > len(dst) {
return nil, 0, ErrDstTooSmall
}
return dst[:d+sz], res, nil
}
dLimit := len(dst) - 10
var lastOffset uint16
var uncompressed int
if debug {
fmt.Printf("convert block start: len(src): %d, len(dst):%d \n", len(src), len(dst))
}
for {
if s >= len(src) {
return dst[:d], 0, ErrCorrupt
}
// Read literal info
token := src[s]
ll := int(token >> 4)
ml := int(lz4MinMatch + (token & 0xf))
// If upper nibble is 15, literal length is extended
if token >= 0xf0 {
for {
s++
if s >= len(src) {
if debug {
fmt.Printf("error reading ll: s (%d) >= len(src) (%d)\n", s, len(src))
}
return dst[:d], 0, ErrCorrupt
}
val := src[s]
ll += int(val)
if val != 255 {
break
}
}
}
// Skip past token
if s+ll >= len(src) {
if debug {
fmt.Printf("error literals: s+ll (%d+%d) >= len(src) (%d)\n", s, ll, len(src))
}
return nil, 0, ErrCorrupt
}
s++
if ll > 0 {
if d+ll > dLimit {
return nil, 0, ErrDstTooSmall
}
if debug {
fmt.Printf("emit %d literals\n", ll)
}
d += emitLiteralGo(dst[d:], src[s:s+ll])
s += ll
uncompressed += ll
}
// Check if we are done...
if s == len(src) && ml == lz4MinMatch {
break
}
// 2 byte offset
if s >= len(src)-2 {
if debug {
fmt.Printf("s (%d) >= len(src)-2 (%d)", s, len(src)-2)
}
return nil, 0, ErrCorrupt
}
offset := binary.LittleEndian.Uint16(src[s:])
s += 2
if offset == 0 {
if debug {
fmt.Printf("error: offset 0, ml: %d, len(src)-s: %d\n", ml, len(src)-s)
}
return nil, 0, ErrCorrupt
}
if int(offset) > uncompressed {
if debug {
fmt.Printf("error: offset (%d)> uncompressed (%d)\n", offset, uncompressed)
}
return nil, 0, ErrCorrupt
}
if ml == lz4MinMatch+15 {
for {
if s >= len(src) {
if debug {
fmt.Printf("error reading ml: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
val := src[s]
s++
ml += int(val)
if val != 255 {
if s >= len(src) {
if debug {
fmt.Printf("error reading ml: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
break
}
}
}
if offset == lastOffset {
if debug {
fmt.Printf("emit repeat, length: %d, offset: %d\n", ml, offset)
}
if !inline {
d += emitRepeat16(dst[d:], offset, ml)
} else {
length := ml
dst := dst[d:]
for len(dst) > 5 {
// Repeat offset, make length cheaper
length -= 4
if length <= 4 {
dst[0] = uint8(length)<<2 | tagCopy1
dst[1] = 0
d += 2
break
}
if length < 8 && offset < 2048 {
// Encode WITH offset
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length)<<2 | tagCopy1
d += 2
break
}
if length < (1<<8)+4 {
length -= 4
dst[2] = uint8(length)
dst[1] = 0
dst[0] = 5<<2 | tagCopy1
d += 3
break
}
if length < (1<<16)+(1<<8) {
length -= 1 << 8
dst[3] = uint8(length >> 8)
dst[2] = uint8(length >> 0)
dst[1] = 0
dst[0] = 6<<2 | tagCopy1
d += 4
break
}
const maxRepeat = (1 << 24) - 1
length -= 1 << 16
left := 0
if length > maxRepeat {
left = length - maxRepeat + 4
length = maxRepeat - 4
}
dst[4] = uint8(length >> 16)
dst[3] = uint8(length >> 8)
dst[2] = uint8(length >> 0)
dst[1] = 0
dst[0] = 7<<2 | tagCopy1
if left > 0 {
d += 5 + emitRepeat16(dst[5:], offset, left)
break
}
d += 5
break
}
}
} else {
if debug {
fmt.Printf("emit copy, length: %d, offset: %d\n", ml, offset)
}
if !inline {
d += emitCopy16(dst[d:], offset, ml)
} else {
length := ml
dst := dst[d:]
for len(dst) > 5 {
// Offset no more than 2 bytes.
if length > 64 {
off := 3
if offset < 2048 {
// emit 8 bytes as tagCopy1, rest as repeats.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(8-4)<<2 | tagCopy1
length -= 8
off = 2
} else {
// Emit a length 60 copy, encoded as 3 bytes.
// Emit remaining as repeat value (minimum 4 bytes).
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = 59<<2 | tagCopy2
length -= 60
}
// Emit remaining as repeats, at least 4 bytes remain.
d += off + emitRepeat16(dst[off:], offset, length)
break
}
if length >= 12 || offset >= 2048 {
// Emit the remaining copy, encoded as 3 bytes.
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = uint8(length-1)<<2 | tagCopy2
d += 3
break
}
// Emit the remaining copy, encoded as 2 bytes.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
d += 2
break
}
}
lastOffset = offset
}
uncompressed += ml
if d > dLimit {
return nil, 0, ErrDstTooSmall
}
}
return dst[:d], uncompressed, nil
}
// ConvertBlockSnappy will convert an LZ4 block and append it
// as a Snappy block without block length to dst.
// The uncompressed size is returned as well.
// dst must have capacity to contain the entire compressed block.
func (l *LZ4Converter) ConvertBlockSnappy(dst, src []byte) ([]byte, int, error) {
if len(src) == 0 {
return dst, 0, nil
}
const debug = false
const lz4MinMatch = 4
s, d := 0, len(dst)
dst = dst[:cap(dst)]
// Use assembly when possible
if !debug && hasAmd64Asm {
res, sz := cvtLZ4BlockSnappyAsm(dst[d:], src)
if res < 0 {
const (
errCorrupt = -1
errDstTooSmall = -2
)
switch res {
case errCorrupt:
return nil, 0, ErrCorrupt
case errDstTooSmall:
return nil, 0, ErrDstTooSmall
default:
return nil, 0, fmt.Errorf("unexpected result: %d", res)
}
}
if d+sz > len(dst) {
return nil, 0, ErrDstTooSmall
}
return dst[:d+sz], res, nil
}
dLimit := len(dst) - 10
var uncompressed int
if debug {
fmt.Printf("convert block start: len(src): %d, len(dst):%d \n", len(src), len(dst))
}
for {
if s >= len(src) {
return nil, 0, ErrCorrupt
}
// Read literal info
token := src[s]
ll := int(token >> 4)
ml := int(lz4MinMatch + (token & 0xf))
// If upper nibble is 15, literal length is extended
if token >= 0xf0 {
for {
s++
if s >= len(src) {
if debug {
fmt.Printf("error reading ll: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
val := src[s]
ll += int(val)
if val != 255 {
break
}
}
}
// Skip past token
if s+ll >= len(src) {
if debug {
fmt.Printf("error literals: s+ll (%d+%d) >= len(src) (%d)\n", s, ll, len(src))
}
return nil, 0, ErrCorrupt
}
s++
if ll > 0 {
if d+ll > dLimit {
return nil, 0, ErrDstTooSmall
}
if debug {
fmt.Printf("emit %d literals\n", ll)
}
d += emitLiteralGo(dst[d:], src[s:s+ll])
s += ll
uncompressed += ll
}
// Check if we are done...
if s == len(src) && ml == lz4MinMatch {
break
}
// 2 byte offset
if s >= len(src)-2 {
if debug {
fmt.Printf("s (%d) >= len(src)-2 (%d)", s, len(src)-2)
}
return nil, 0, ErrCorrupt
}
offset := binary.LittleEndian.Uint16(src[s:])
s += 2
if offset == 0 {
if debug {
fmt.Printf("error: offset 0, ml: %d, len(src)-s: %d\n", ml, len(src)-s)
}
return nil, 0, ErrCorrupt
}
if int(offset) > uncompressed {
if debug {
fmt.Printf("error: offset (%d)> uncompressed (%d)\n", offset, uncompressed)
}
return nil, 0, ErrCorrupt
}
if ml == lz4MinMatch+15 {
for {
if s >= len(src) {
if debug {
fmt.Printf("error reading ml: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
val := src[s]
s++
ml += int(val)
if val != 255 {
if s >= len(src) {
if debug {
fmt.Printf("error reading ml: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
break
}
}
}
if debug {
fmt.Printf("emit copy, length: %d, offset: %d\n", ml, offset)
}
length := ml
// d += emitCopyNoRepeat(dst[d:], int(offset), ml)
for length > 0 {
if d >= dLimit {
return nil, 0, ErrDstTooSmall
}
// Offset no more than 2 bytes.
if length > 64 {
// Emit a length 64 copy, encoded as 3 bytes.
dst[d+2] = uint8(offset >> 8)
dst[d+1] = uint8(offset)
dst[d+0] = 63<<2 | tagCopy2
length -= 64
d += 3
continue
}
if length >= 12 || offset >= 2048 || length < 4 {
// Emit the remaining copy, encoded as 3 bytes.
dst[d+2] = uint8(offset >> 8)
dst[d+1] = uint8(offset)
dst[d+0] = uint8(length-1)<<2 | tagCopy2
d += 3
break
}
// Emit the remaining copy, encoded as 2 bytes.
dst[d+1] = uint8(offset)
dst[d+0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
d += 2
break
}
uncompressed += ml
if d > dLimit {
return nil, 0, ErrDstTooSmall
}
}
return dst[:d], uncompressed, nil
}
// emitRepeat writes a repeat chunk and returns the number of bytes written.
// Length must be at least 4 and < 1<<24
func emitRepeat16(dst []byte, offset uint16, length int) int {
// Repeat offset, make length cheaper
length -= 4
if length <= 4 {
dst[0] = uint8(length)<<2 | tagCopy1
dst[1] = 0
return 2
}
if length < 8 && offset < 2048 {
// Encode WITH offset
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length)<<2 | tagCopy1
return 2
}
if length < (1<<8)+4 {
length -= 4
dst[2] = uint8(length)
dst[1] = 0
dst[0] = 5<<2 | tagCopy1
return 3
}
if length < (1<<16)+(1<<8) {
length -= 1 << 8
dst[3] = uint8(length >> 8)
dst[2] = uint8(length >> 0)
dst[1] = 0
dst[0] = 6<<2 | tagCopy1
return 4
}
const maxRepeat = (1 << 24) - 1
length -= 1 << 16
left := 0
if length > maxRepeat {
left = length - maxRepeat + 4
length = maxRepeat - 4
}
dst[4] = uint8(length >> 16)
dst[3] = uint8(length >> 8)
dst[2] = uint8(length >> 0)
dst[1] = 0
dst[0] = 7<<2 | tagCopy1
if left > 0 {
return 5 + emitRepeat16(dst[5:], offset, left)
}
return 5
}
// emitCopy writes a copy chunk and returns the number of bytes written.
//
// It assumes that:
//
// dst is long enough to hold the encoded bytes
// 1 <= offset && offset <= math.MaxUint16
// 4 <= length && length <= math.MaxUint32
func emitCopy16(dst []byte, offset uint16, length int) int {
// Offset no more than 2 bytes.
if length > 64 {
off := 3
if offset < 2048 {
// emit 8 bytes as tagCopy1, rest as repeats.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(8-4)<<2 | tagCopy1
length -= 8
off = 2
} else {
// Emit a length 60 copy, encoded as 3 bytes.
// Emit remaining as repeat value (minimum 4 bytes).
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = 59<<2 | tagCopy2
length -= 60
}
// Emit remaining as repeats, at least 4 bytes remain.
return off + emitRepeat16(dst[off:], offset, length)
}
if length >= 12 || offset >= 2048 {
// Emit the remaining copy, encoded as 3 bytes.
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = uint8(length-1)<<2 | tagCopy2
return 3
}
// Emit the remaining copy, encoded as 2 bytes.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
return 2
}
// emitLiteral writes a literal chunk and returns the number of bytes written.
//
// It assumes that:
//
// dst is long enough to hold the encoded bytes
// 0 <= len(lit) && len(lit) <= math.MaxUint32
func emitLiteralGo(dst, lit []byte) int {
if len(lit) == 0 {
return 0
}
i, n := 0, uint(len(lit)-1)
switch {
case n < 60:
dst[0] = uint8(n)<<2 | tagLiteral
i = 1
case n < 1<<8:
dst[1] = uint8(n)
dst[0] = 60<<2 | tagLiteral
i = 2
case n < 1<<16:
dst[2] = uint8(n >> 8)
dst[1] = uint8(n)
dst[0] = 61<<2 | tagLiteral
i = 3
case n < 1<<24:
dst[3] = uint8(n >> 16)
dst[2] = uint8(n >> 8)
dst[1] = uint8(n)
dst[0] = 62<<2 | tagLiteral
i = 4
default:
dst[4] = uint8(n >> 24)
dst[3] = uint8(n >> 16)
dst[2] = uint8(n >> 8)
dst[1] = uint8(n)
dst[0] = 63<<2 | tagLiteral
i = 5
}
return i + copy(dst[i:], lit)
}
Server/vendor/github.com/klauspost/compress/s2/lz4sconvert.go
Generated Vendored
+467
View File
@@ -0,0 +1,467 @@
// Copyright (c) 2022 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package s2
import (
"encoding/binary"
"fmt"
)
// LZ4sConverter provides conversion from LZ4s.
// (Intel modified LZ4 Blocks)
// https://cdrdv2-public.intel.com/743912/743912-qat-programmers-guide-v2.0.pdf
// LZ4s is a variant of LZ4 block format. LZ4s should be considered as an intermediate compressed block format.
// The LZ4s format is selected when the application sets the compType to CPA_DC_LZ4S in CpaDcSessionSetupData.
// The LZ4s block returned by the Intel® QAT hardware can be used by an external
// software post-processing to generate other compressed data formats.
// The following table lists the differences between LZ4 and LZ4s block format. LZ4s block format uses
// the same high-level formatting as LZ4 block format with the following encoding changes:
// For Min Match of 4 bytes, Copy length value 1-15 means length 4-18 with 18 bytes adding an extra byte.
// ONLY "Min match of 4 bytes" is supported.
type LZ4sConverter struct {
}
// ConvertBlock will convert an LZ4s block and append it as an S2
// block without block length to dst.
// The uncompressed size is returned as well.
// dst must have capacity to contain the entire compressed block.
func (l *LZ4sConverter) ConvertBlock(dst, src []byte) ([]byte, int, error) {
if len(src) == 0 {
return dst, 0, nil
}
const debug = false
const inline = true
const lz4MinMatch = 3
s, d := 0, len(dst)
dst = dst[:cap(dst)]
if !debug && hasAmd64Asm {
res, sz := cvtLZ4sBlockAsm(dst[d:], src)
if res < 0 {
const (
errCorrupt = -1
errDstTooSmall = -2
)
switch res {
case errCorrupt:
return nil, 0, ErrCorrupt
case errDstTooSmall:
return nil, 0, ErrDstTooSmall
default:
return nil, 0, fmt.Errorf("unexpected result: %d", res)
}
}
if d+sz > len(dst) {
return nil, 0, ErrDstTooSmall
}
return dst[:d+sz], res, nil
}
dLimit := len(dst) - 10
var lastOffset uint16
var uncompressed int
if debug {
fmt.Printf("convert block start: len(src): %d, len(dst):%d \n", len(src), len(dst))
}
for {
if s >= len(src) {
return dst[:d], 0, ErrCorrupt
}
// Read literal info
token := src[s]
ll := int(token >> 4)
ml := int(lz4MinMatch + (token & 0xf))
// If upper nibble is 15, literal length is extended
if token >= 0xf0 {
for {
s++
if s >= len(src) {
if debug {
fmt.Printf("error reading ll: s (%d) >= len(src) (%d)\n", s, len(src))
}
return dst[:d], 0, ErrCorrupt
}
val := src[s]
ll += int(val)
if val != 255 {
break
}
}
}
// Skip past token
if s+ll >= len(src) {
if debug {
fmt.Printf("error literals: s+ll (%d+%d) >= len(src) (%d)\n", s, ll, len(src))
}
return nil, 0, ErrCorrupt
}
s++
if ll > 0 {
if d+ll > dLimit {
return nil, 0, ErrDstTooSmall
}
if debug {
fmt.Printf("emit %d literals\n", ll)
}
d += emitLiteralGo(dst[d:], src[s:s+ll])
s += ll
uncompressed += ll
}
// Check if we are done...
if ml == lz4MinMatch {
if s == len(src) {
break
}
// 0 bytes.
continue
}
// 2 byte offset
if s >= len(src)-2 {
if debug {
fmt.Printf("s (%d) >= len(src)-2 (%d)", s, len(src)-2)
}
return nil, 0, ErrCorrupt
}
offset := binary.LittleEndian.Uint16(src[s:])
s += 2
if offset == 0 {
if debug {
fmt.Printf("error: offset 0, ml: %d, len(src)-s: %d\n", ml, len(src)-s)
}
return nil, 0, ErrCorrupt
}
if int(offset) > uncompressed {
if debug {
fmt.Printf("error: offset (%d)> uncompressed (%d)\n", offset, uncompressed)
}
return nil, 0, ErrCorrupt
}
if ml == lz4MinMatch+15 {
for {
if s >= len(src) {
if debug {
fmt.Printf("error reading ml: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
val := src[s]
s++
ml += int(val)
if val != 255 {
if s >= len(src) {
if debug {
fmt.Printf("error reading ml: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
break
}
}
}
if offset == lastOffset {
if debug {
fmt.Printf("emit repeat, length: %d, offset: %d\n", ml, offset)
}
if !inline {
d += emitRepeat16(dst[d:], offset, ml)
} else {
length := ml
dst := dst[d:]
for len(dst) > 5 {
// Repeat offset, make length cheaper
length -= 4
if length <= 4 {
dst[0] = uint8(length)<<2 | tagCopy1
dst[1] = 0
d += 2
break
}
if length < 8 && offset < 2048 {
// Encode WITH offset
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length)<<2 | tagCopy1
d += 2
break
}
if length < (1<<8)+4 {
length -= 4
dst[2] = uint8(length)
dst[1] = 0
dst[0] = 5<<2 | tagCopy1
d += 3
break
}
if length < (1<<16)+(1<<8) {
length -= 1 << 8
dst[3] = uint8(length >> 8)
dst[2] = uint8(length >> 0)
dst[1] = 0
dst[0] = 6<<2 | tagCopy1
d += 4
break
}
const maxRepeat = (1 << 24) - 1
length -= 1 << 16
left := 0
if length > maxRepeat {
left = length - maxRepeat + 4
length = maxRepeat - 4
}
dst[4] = uint8(length >> 16)
dst[3] = uint8(length >> 8)
dst[2] = uint8(length >> 0)
dst[1] = 0
dst[0] = 7<<2 | tagCopy1
if left > 0 {
d += 5 + emitRepeat16(dst[5:], offset, left)
break
}
d += 5
break
}
}
} else {
if debug {
fmt.Printf("emit copy, length: %d, offset: %d\n", ml, offset)
}
if !inline {
d += emitCopy16(dst[d:], offset, ml)
} else {
length := ml
dst := dst[d:]
for len(dst) > 5 {
// Offset no more than 2 bytes.
if length > 64 {
off := 3
if offset < 2048 {
// emit 8 bytes as tagCopy1, rest as repeats.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(8-4)<<2 | tagCopy1
length -= 8
off = 2
} else {
// Emit a length 60 copy, encoded as 3 bytes.
// Emit remaining as repeat value (minimum 4 bytes).
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = 59<<2 | tagCopy2
length -= 60
}
// Emit remaining as repeats, at least 4 bytes remain.
d += off + emitRepeat16(dst[off:], offset, length)
break
}
if length >= 12 || offset >= 2048 {
// Emit the remaining copy, encoded as 3 bytes.
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = uint8(length-1)<<2 | tagCopy2
d += 3
break
}
// Emit the remaining copy, encoded as 2 bytes.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
d += 2
break
}
}
lastOffset = offset
}
uncompressed += ml
if d > dLimit {
return nil, 0, ErrDstTooSmall
}
}
return dst[:d], uncompressed, nil
}
// ConvertBlockSnappy will convert an LZ4s block and append it
// as a Snappy block without block length to dst.
// The uncompressed size is returned as well.
// dst must have capacity to contain the entire compressed block.
func (l *LZ4sConverter) ConvertBlockSnappy(dst, src []byte) ([]byte, int, error) {
if len(src) == 0 {
return dst, 0, nil
}
const debug = false
const lz4MinMatch = 3
s, d := 0, len(dst)
dst = dst[:cap(dst)]
// Use assembly when possible
if !debug && hasAmd64Asm {
res, sz := cvtLZ4sBlockSnappyAsm(dst[d:], src)
if res < 0 {
const (
errCorrupt = -1
errDstTooSmall = -2
)
switch res {
case errCorrupt:
return nil, 0, ErrCorrupt
case errDstTooSmall:
return nil, 0, ErrDstTooSmall
default:
return nil, 0, fmt.Errorf("unexpected result: %d", res)
}
}
if d+sz > len(dst) {
return nil, 0, ErrDstTooSmall
}
return dst[:d+sz], res, nil
}
dLimit := len(dst) - 10
var uncompressed int
if debug {
fmt.Printf("convert block start: len(src): %d, len(dst):%d \n", len(src), len(dst))
}
for {
if s >= len(src) {
return nil, 0, ErrCorrupt
}
// Read literal info
token := src[s]
ll := int(token >> 4)
ml := int(lz4MinMatch + (token & 0xf))
// If upper nibble is 15, literal length is extended
if token >= 0xf0 {
for {
s++
if s >= len(src) {
if debug {
fmt.Printf("error reading ll: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
val := src[s]
ll += int(val)
if val != 255 {
break
}
}
}
// Skip past token
if s+ll >= len(src) {
if debug {
fmt.Printf("error literals: s+ll (%d+%d) >= len(src) (%d)\n", s, ll, len(src))
}
return nil, 0, ErrCorrupt
}
s++
if ll > 0 {
if d+ll > dLimit {
return nil, 0, ErrDstTooSmall
}
if debug {
fmt.Printf("emit %d literals\n", ll)
}
d += emitLiteralGo(dst[d:], src[s:s+ll])
s += ll
uncompressed += ll
}
// Check if we are done...
if ml == lz4MinMatch {
if s == len(src) {
break
}
// 0 bytes.
continue
}
// 2 byte offset
if s >= len(src)-2 {
if debug {
fmt.Printf("s (%d) >= len(src)-2 (%d)", s, len(src)-2)
}
return nil, 0, ErrCorrupt
}
offset := binary.LittleEndian.Uint16(src[s:])
s += 2
if offset == 0 {
if debug {
fmt.Printf("error: offset 0, ml: %d, len(src)-s: %d\n", ml, len(src)-s)
}
return nil, 0, ErrCorrupt
}
if int(offset) > uncompressed {
if debug {
fmt.Printf("error: offset (%d)> uncompressed (%d)\n", offset, uncompressed)
}
return nil, 0, ErrCorrupt
}
if ml == lz4MinMatch+15 {
for {
if s >= len(src) {
if debug {
fmt.Printf("error reading ml: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
val := src[s]
s++
ml += int(val)
if val != 255 {
if s >= len(src) {
if debug {
fmt.Printf("error reading ml: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
break
}
}
}
if debug {
fmt.Printf("emit copy, length: %d, offset: %d\n", ml, offset)
}
length := ml
// d += emitCopyNoRepeat(dst[d:], int(offset), ml)
for length > 0 {
if d >= dLimit {
return nil, 0, ErrDstTooSmall
}
// Offset no more than 2 bytes.
if length > 64 {
// Emit a length 64 copy, encoded as 3 bytes.
dst[d+2] = uint8(offset >> 8)
dst[d+1] = uint8(offset)
dst[d+0] = 63<<2 | tagCopy2
length -= 64
d += 3
continue
}
if length >= 12 || offset >= 2048 || length < 4 {
// Emit the remaining copy, encoded as 3 bytes.
dst[d+2] = uint8(offset >> 8)
dst[d+1] = uint8(offset)
dst[d+0] = uint8(length-1)<<2 | tagCopy2
d += 3
break
}
// Emit the remaining copy, encoded as 2 bytes.
dst[d+1] = uint8(offset)
dst[d+0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
d += 2
break
}
uncompressed += ml
if d > dLimit {
return nil, 0, ErrDstTooSmall
}
}
return dst[:d], uncompressed, nil
}
Server/vendor/github.com/klauspost/compress/s2/reader.go
Generated Vendored
+1075
View File
File diff suppressed because it is too large Load Diff
Server/vendor/github.com/klauspost/compress/s2/s2.go
Generated Vendored
+151
View File
@@ -0,0 +1,151 @@
// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package s2 implements the S2 compression format.
//
// S2 is an extension of Snappy. Similar to Snappy S2 is aimed for high throughput,
// which is why it features concurrent compression for bigger payloads.
//
// Decoding is compatible with Snappy compressed content,
// but content compressed with S2 cannot be decompressed by Snappy.
//
// For more information on Snappy/S2 differences see README in: https://github.com/klauspost/compress/tree/master/s2
//
// There are actually two S2 formats: block and stream. They are related,
// but different: trying to decompress block-compressed data as a S2 stream
// will fail, and vice versa. The block format is the Decode and Encode
// functions and the stream format is the Reader and Writer types.
//
// A "better" compression option is available. This will trade some compression
// speed
//
// The block format, the more common case, is used when the complete size (the
// number of bytes) of the original data is known upfront, at the time
// compression starts. The stream format, also known as the framing format, is
// for when that isn't always true.
//
// Blocks to not offer much data protection, so it is up to you to
// add data validation of decompressed blocks.
//
// Streams perform CRC validation of the decompressed data.
// Stream compression will also be performed on multiple CPU cores concurrently
// significantly improving throughput.
package s2
import (
"bytes"
"hash/crc32"
"github.com/klauspost/compress/internal/race"
)
/*
Each encoded block begins with the varint-encoded length of the decoded data,
followed by a sequence of chunks. Chunks begin and end on byte boundaries. The
first byte of each chunk is broken into its 2 least and 6 most significant bits
called l and m: l ranges in [0, 4) and m ranges in [0, 64). l is the chunk tag.
Zero means a literal tag. All other values mean a copy tag.
For literal tags:
- If m < 60, the next 1 + m bytes are literal bytes.
- Otherwise, let n be the little-endian unsigned integer denoted by the next
m - 59 bytes. The next 1 + n bytes after that are literal bytes.
For copy tags, length bytes are copied from offset bytes ago, in the style of
Lempel-Ziv compression algorithms. In particular:
- For l == 1, the offset ranges in [0, 1<<11) and the length in [4, 12).
The length is 4 + the low 3 bits of m. The high 3 bits of m form bits 8-10
of the offset. The next byte is bits 0-7 of the offset.
- For l == 2, the offset ranges in [0, 1<<16) and the length in [1, 65).
The length is 1 + m. The offset is the little-endian unsigned integer
denoted by the next 2 bytes.
- For l == 3, the offset ranges in [0, 1<<32) and the length in
[1, 65). The length is 1 + m. The offset is the little-endian unsigned
integer denoted by the next 4 bytes.
*/
const (
tagLiteral = 0x00
tagCopy1 = 0x01
tagCopy2 = 0x02
tagCopy4 = 0x03
)
const (
checksumSize = 4
chunkHeaderSize = 4
magicChunk = "\xff\x06\x00\x00" + magicBody
magicChunkSnappy = "\xff\x06\x00\x00" + magicBodySnappy
magicBodySnappy = "sNaPpY"
magicBody = "S2sTwO"
// maxBlockSize is the maximum size of the input to encodeBlock.
//
// For the framing format (Writer type instead of Encode function),
// this is the maximum uncompressed size of a block.
maxBlockSize = 4 << 20
// minBlockSize is the minimum size of block setting when creating a writer.
minBlockSize = 4 << 10
skippableFrameHeader = 4
maxChunkSize = 1<<24 - 1 // 16777215
// Default block size
defaultBlockSize = 1 << 20
// maxSnappyBlockSize is the maximum snappy block size.
maxSnappyBlockSize = 1 << 16
obufHeaderLen = checksumSize + chunkHeaderSize
)
const (
chunkTypeCompressedData = 0x00
chunkTypeUncompressedData = 0x01
ChunkTypeIndex = 0x99
chunkTypePadding = 0xfe
chunkTypeStreamIdentifier = 0xff
)
var (
crcTable = crc32.MakeTable(crc32.Castagnoli)
magicChunkSnappyBytes = []byte(magicChunkSnappy) // Can be passed to functions where it escapes.
magicChunkBytes = []byte(magicChunk) // Can be passed to functions where it escapes.
)
// crc implements the checksum specified in section 3 of
// https://github.com/google/snappy/blob/master/framing_format.txt
func crc(b []byte) uint32 {
race.ReadSlice(b)
c := crc32.Update(0, crcTable, b)
return c>>15 | c<<17 + 0xa282ead8
}
// literalExtraSize returns the extra size of encoding n literals.
// n should be >= 0 and <= math.MaxUint32.
func literalExtraSize(n int64) int64 {
if n == 0 {
return 0
}
switch {
case n < 60:
return 1
case n < 1<<8:
return 2
case n < 1<<16:
return 3
case n < 1<<24:
return 4
default:
return 5
}
}
type byter interface {
Bytes() []byte
}
var _ byter = &bytes.Buffer{}
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module github.com/klauspost/compress
go 1.22
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cmd/snappytool/snappytool
testdata/bench
# These explicitly listed benchmark data files are for an obsolete version of
# snappy_test.go.
testdata/alice29.txt
testdata/asyoulik.txt
testdata/fireworks.jpeg
testdata/geo.protodata
testdata/html
testdata/html_x_4
testdata/kppkn.gtb
testdata/lcet10.txt
testdata/paper-100k.pdf
testdata/plrabn12.txt
testdata/urls.10K
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# This is the official list of Snappy-Go authors for copyright purposes.
# This file is distinct from the CONTRIBUTORS files.
# See the latter for an explanation.
# Names should be added to this file as
# Name or Organization <email address>
# The email address is not required for organizations.
# Please keep the list sorted.
Amazon.com, Inc
Damian Gryski <dgryski@gmail.com>
Eric Buth <eric@topos.com>
Google Inc.
Jan Mercl <0xjnml@gmail.com>
Klaus Post <klauspost@gmail.com>
Rodolfo Carvalho <rhcarvalho@gmail.com>
Sebastien Binet <seb.binet@gmail.com>
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# This is the official list of people who can contribute
# (and typically have contributed) code to the Snappy-Go repository.
# The AUTHORS file lists the copyright holders; this file
# lists people. For example, Google employees are listed here
# but not in AUTHORS, because Google holds the copyright.
#
# The submission process automatically checks to make sure
# that people submitting code are listed in this file (by email address).
#
# Names should be added to this file only after verifying that
# the individual or the individual's organization has agreed to
# the appropriate Contributor License Agreement, found here:
#
# http://code.google.com/legal/individual-cla-v1.0.html
# http://code.google.com/legal/corporate-cla-v1.0.html
#
# The agreement for individuals can be filled out on the web.
#
# When adding J Random Contributor's name to this file,
# either J's name or J's organization's name should be
# added to the AUTHORS file, depending on whether the
# individual or corporate CLA was used.
# Names should be added to this file like so:
# Name <email address>
# Please keep the list sorted.
Alex Legg <alexlegg@google.com>
Damian Gryski <dgryski@gmail.com>
Eric Buth <eric@topos.com>
Jan Mercl <0xjnml@gmail.com>
Jonathan Swinney <jswinney@amazon.com>
Kai Backman <kaib@golang.org>
Klaus Post <klauspost@gmail.com>
Marc-Antoine Ruel <maruel@chromium.org>
Nigel Tao <nigeltao@golang.org>
Rob Pike <r@golang.org>
Rodolfo Carvalho <rhcarvalho@gmail.com>
Russ Cox <rsc@golang.org>
Sebastien Binet <seb.binet@gmail.com>
Server/vendor/github.com/klauspost/compress/snappy/LICENSE
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Copyright (c) 2011 The Snappy-Go Authors. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Server/vendor/github.com/klauspost/compress/snappy/README.md
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# snappy
The Snappy compression format in the Go programming language.
This is a drop-in replacement for `github.com/golang/snappy`.
It provides a full, compatible replacement of the Snappy package by simply changing imports.
See [Snappy Compatibility](https://github.com/klauspost/compress/tree/master/s2#snappy-compatibility) in the S2 documentation.
"Better" compression mode is used. For buffered streams concurrent compression is used.
For more options use the [s2 package](https://pkg.go.dev/github.com/klauspost/compress/s2).
# usage
Replace imports `github.com/golang/snappy` with `github.com/klauspost/compress/snappy`.
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// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package snappy
import (
"io"
"github.com/klauspost/compress/s2"
)
var (
// ErrCorrupt reports that the input is invalid.
ErrCorrupt = s2.ErrCorrupt
// ErrTooLarge reports that the uncompressed length is too large.
ErrTooLarge = s2.ErrTooLarge
// ErrUnsupported reports that the input isn't supported.
ErrUnsupported = s2.ErrUnsupported
)
const (
// maxBlockSize is the maximum size of the input to encodeBlock. It is not
// part of the wire format per se, but some parts of the encoder assume
// that an offset fits into a uint16.
//
// Also, for the framing format (Writer type instead of Encode function),
// https://github.com/google/snappy/blob/master/framing_format.txt says
// that "the uncompressed data in a chunk must be no longer than 65536
// bytes".
maxBlockSize = 65536
)
// DecodedLen returns the length of the decoded block.
func DecodedLen(src []byte) (int, error) {
return s2.DecodedLen(src)
}
// Decode returns the decoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire decoded block.
// Otherwise, a newly allocated slice will be returned.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// Decode handles the Snappy block format, not the Snappy stream format.
func Decode(dst, src []byte) ([]byte, error) {
return s2.Decode(dst, src)
}
// NewReader returns a new Reader that decompresses from r, using the framing
// format described at
// https://github.com/google/snappy/blob/master/framing_format.txt
func NewReader(r io.Reader) *Reader {
return s2.NewReader(r, s2.ReaderMaxBlockSize(maxBlockSize))
}
// Reader is an io.Reader that can read Snappy-compressed bytes.
//
// Reader handles the Snappy stream format, not the Snappy block format.
type Reader = s2.Reader
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// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package snappy
import (
"io"
"github.com/klauspost/compress/s2"
)
// Encode returns the encoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire encoded block.
// Otherwise, a newly allocated slice will be returned.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// Encode handles the Snappy block format, not the Snappy stream format.
func Encode(dst, src []byte) []byte {
return s2.EncodeSnappyBetter(dst, src)
}
// MaxEncodedLen returns the maximum length of a snappy block, given its
// uncompressed length.
//
// It will return a negative value if srcLen is too large to encode.
func MaxEncodedLen(srcLen int) int {
return s2.MaxEncodedLen(srcLen)
}
// NewWriter returns a new Writer that compresses to w.
//
// The Writer returned does not buffer writes. There is no need to Flush or
// Close such a Writer.
//
// Deprecated: the Writer returned is not suitable for many small writes, only
// for few large writes. Use NewBufferedWriter instead, which is efficient
// regardless of the frequency and shape of the writes, and remember to Close
// that Writer when done.
func NewWriter(w io.Writer) *Writer {
return s2.NewWriter(w, s2.WriterSnappyCompat(), s2.WriterBetterCompression(), s2.WriterFlushOnWrite(), s2.WriterConcurrency(1))
}
// NewBufferedWriter returns a new Writer that compresses to w, using the
// framing format described at
// https://github.com/google/snappy/blob/master/framing_format.txt
//
// The Writer returned buffers writes. Users must call Close to guarantee all
// data has been forwarded to the underlying io.Writer. They may also call
// Flush zero or more times before calling Close.
func NewBufferedWriter(w io.Writer) *Writer {
return s2.NewWriter(w, s2.WriterSnappyCompat(), s2.WriterBetterCompression())
}
// Writer is an io.Writer that can write Snappy-compressed bytes.
//
// Writer handles the Snappy stream format, not the Snappy block format.
type Writer = s2.Writer
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// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package snappy implements the Snappy compression format. It aims for very
// high speeds and reasonable compression.
//
// There are actually two Snappy formats: block and stream. They are related,
// but different: trying to decompress block-compressed data as a Snappy stream
// will fail, and vice versa. The block format is the Decode and Encode
// functions and the stream format is the Reader and Writer types.
//
// The block format, the more common case, is used when the complete size (the
// number of bytes) of the original data is known upfront, at the time
// compression starts. The stream format, also known as the framing format, is
// for when that isn't always true.
//
// The canonical, C++ implementation is at https://github.com/google/snappy and
// it only implements the block format.
package snappy
/*
Each encoded block begins with the varint-encoded length of the decoded data,
followed by a sequence of chunks. Chunks begin and end on byte boundaries. The
first byte of each chunk is broken into its 2 least and 6 most significant bits
called l and m: l ranges in [0, 4) and m ranges in [0, 64). l is the chunk tag.
Zero means a literal tag. All other values mean a copy tag.
For literal tags:
- If m < 60, the next 1 + m bytes are literal bytes.
- Otherwise, let n be the little-endian unsigned integer denoted by the next
m - 59 bytes. The next 1 + n bytes after that are literal bytes.
For copy tags, length bytes are copied from offset bytes ago, in the style of
Lempel-Ziv compression algorithms. In particular:
- For l == 1, the offset ranges in [0, 1<<11) and the length in [4, 12).
The length is 4 + the low 3 bits of m. The high 3 bits of m form bits 8-10
of the offset. The next byte is bits 0-7 of the offset.
- For l == 2, the offset ranges in [0, 1<<16) and the length in [1, 65).
The length is 1 + m. The offset is the little-endian unsigned integer
denoted by the next 2 bytes.
- For l == 3, this tag is a legacy format that is no longer issued by most
encoders. Nonetheless, the offset ranges in [0, 1<<32) and the length in
[1, 65). The length is 1 + m. The offset is the little-endian unsigned
integer denoted by the next 4 bytes.
*/
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# zstd
[Zstandard](https://facebook.github.io/zstd/) is a real-time compression algorithm, providing high compression ratios.
It offers a very wide range of compression / speed trade-off, while being backed by a very fast decoder.
A high performance compression algorithm is implemented. For now focused on speed.
This package provides [compression](#Compressor) to and [decompression](#Decompressor) of Zstandard content.
This package is pure Go. Use `noasm` and `nounsafe` to disable relevant features.
The `zstd` package is provided as open source software using a Go standard license.
Currently the package is heavily optimized for 64 bit processors and will be significantly slower on 32 bit processors.
For seekable zstd streams, see [this excellent package](https://github.com/SaveTheRbtz/zstd-seekable-format-go).
## Installation
Install using `go get -u github.com/klauspost/compress`. The package is located in `github.com/klauspost/compress/zstd`.
[![Go Reference](https://pkg.go.dev/badge/github.com/klauspost/compress/zstd.svg)](https://pkg.go.dev/github.com/klauspost/compress/zstd)
## Compressor
### Status:
STABLE - there may always be subtle bugs, a wide variety of content has been tested and the library is actively
used by several projects. This library is being [fuzz-tested](https://github.com/klauspost/compress-fuzz) for all updates.
There may still be specific combinations of data types/size/settings that could lead to edge cases,
so as always, testing is recommended.
For now, a high speed (fastest) and medium-fast (default) compressor has been implemented.
* The "Fastest" compression ratio is roughly equivalent to zstd level 1.
* The "Default" compression ratio is roughly equivalent to zstd level 3 (default).
* The "Better" compression ratio is roughly equivalent to zstd level 7.
* The "Best" compression ratio is roughly equivalent to zstd level 11.
In terms of speed, it is typically 2x as fast as the stdlib deflate/gzip in its fastest mode.
The compression ratio compared to stdlib is around level 3, but usually 3x as fast.
### Usage
An Encoder can be used for either compressing a stream via the
`io.WriteCloser` interface supported by the Encoder or as multiple independent
tasks via the `EncodeAll` function.
Smaller encodes are encouraged to use the EncodeAll function.
Use `NewWriter` to create a new instance that can be used for both.
To create a writer with default options, do like this:
```Go
// Compress input to output.
func Compress(in io.Reader, out io.Writer) error {
enc, err := zstd.NewWriter(out)
if err != nil {
return err
}
_, err = io.Copy(enc, in)
if err != nil {
enc.Close()
return err
}
return enc.Close()
}
```
Now you can encode by writing data to `enc`. The output will be finished writing when `Close()` is called.
Even if your encode fails, you should still call `Close()` to release any resources that may be held up.
The above is fine for big encodes. However, whenever possible try to *reuse* the writer.
To reuse the encoder, you can use the `Reset(io.Writer)` function to change to another output.
This will allow the encoder to reuse all resources and avoid wasteful allocations.
Currently stream encoding has 'light' concurrency, meaning up to 2 goroutines can be working on part
of a stream. This is independent of the `WithEncoderConcurrency(n)`, but that is likely to change
in the future. So if you want to limit concurrency for future updates, specify the concurrency
you would like.
If you would like stream encoding to be done without spawning async goroutines, use `WithEncoderConcurrency(1)`
which will compress input as each block is completed, blocking on writes until each has completed.
You can specify your desired compression level using `WithEncoderLevel()` option. Currently only pre-defined
compression settings can be specified.
#### Future Compatibility Guarantees
This will be an evolving project. When using this package it is important to note that both the compression efficiency and speed may change.
The goal will be to keep the default efficiency at the default zstd (level 3).
However the encoding should never be assumed to remain the same,
and you should not use hashes of compressed output for similarity checks.
The Encoder can be assumed to produce the same output from the exact same code version.
However, the may be modes in the future that break this,
although they will not be enabled without an explicit option.
This encoder is not designed to (and will probably never) output the exact same bitstream as the reference encoder.
Also note, that the cgo decompressor currently does not [report all errors on invalid input](https://github.com/DataDog/zstd/issues/59),
[omits error checks](https://github.com/DataDog/zstd/issues/61), [ignores checksums](https://github.com/DataDog/zstd/issues/43)
and seems to ignore concatenated streams, even though [it is part of the spec](https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#frames).
#### Blocks
For compressing small blocks, the returned encoder has a function called `EncodeAll(src, dst []byte) []byte`.
`EncodeAll` will encode all input in src and append it to dst.
This function can be called concurrently.
Each call will only run on a same goroutine as the caller.
Encoded blocks can be concatenated and the result will be the combined input stream.
Data compressed with EncodeAll can be decoded with the Decoder, using either a stream or `DecodeAll`.
Especially when encoding blocks you should take special care to reuse the encoder.
This will effectively make it run without allocations after a warmup period.
To make it run completely without allocations, supply a destination buffer with space for all content.
```Go
import "github.com/klauspost/compress/zstd"
// Create a writer that caches compressors.
// For this operation type we supply a nil Reader.
var encoder, _ = zstd.NewWriter(nil)
// Compress a buffer.
// If you have a destination buffer, the allocation in the call can also be eliminated.
func Compress(src []byte) []byte {
return encoder.EncodeAll(src, make([]byte, 0, len(src)))
}
```
You can control the maximum number of concurrent encodes using the `WithEncoderConcurrency(n)`
option when creating the writer.
Using the Encoder for both a stream and individual blocks concurrently is safe.
### Performance
I have collected some speed examples to compare speed and compression against other compressors.
* `file` is the input file.
* `out` is the compressor used. `zskp` is this package. `zstd` is the Datadog cgo library. `gzstd/gzkp` is gzip standard and this library.
* `level` is the compression level used. For `zskp` level 1 is "fastest", level 2 is "default"; 3 is "better", 4 is "best".
* `insize`/`outsize` is the input/output size.
* `millis` is the number of milliseconds used for compression.
* `mb/s` is megabytes (2^20 bytes) per second.
```
Silesia Corpus:
http://sun.aei.polsl.pl/~sdeor/corpus/silesia.zip
This package:
file out level insize outsize millis mb/s
silesia.tar zskp 1 211947520 73821326 634 318.47
silesia.tar zskp 2 211947520 67655404 1508 133.96
silesia.tar zskp 3 211947520 64746933 3000 67.37
silesia.tar zskp 4 211947520 60073508 16926 11.94
cgo zstd:
silesia.tar zstd 1 211947520 73605392 543 371.56
silesia.tar zstd 3 211947520 66793289 864 233.68
silesia.tar zstd 6 211947520 62916450 1913 105.66
silesia.tar zstd 9 211947520 60212393 5063 39.92
gzip, stdlib/this package:
silesia.tar gzstd 1 211947520 80007735 1498 134.87
silesia.tar gzkp 1 211947520 80088272 1009 200.31
GOB stream of binary data. Highly compressible.
https://files.klauspost.com/compress/gob-stream.7z
file out level insize outsize millis mb/s
gob-stream zskp 1 1911399616 233948096 3230 564.34
gob-stream zskp 2 1911399616 203997694 4997 364.73
gob-stream zskp 3 1911399616 173526523 13435 135.68
gob-stream zskp 4 1911399616 162195235 47559 38.33
gob-stream zstd 1 1911399616 249810424 2637 691.26
gob-stream zstd 3 1911399616 208192146 3490 522.31
gob-stream zstd 6 1911399616 193632038 6687 272.56
gob-stream zstd 9 1911399616 177620386 16175 112.70
gob-stream gzstd 1 1911399616 357382013 9046 201.49
gob-stream gzkp 1 1911399616 359136669 4885 373.08
The test data for the Large Text Compression Benchmark is the first
10^9 bytes of the English Wikipedia dump on Mar. 3, 2006.
http://mattmahoney.net/dc/textdata.html
file out level insize outsize millis mb/s
enwik9 zskp 1 1000000000 343833605 3687 258.64
enwik9 zskp 2 1000000000 317001237 7672 124.29
enwik9 zskp 3 1000000000 291915823 15923 59.89
enwik9 zskp 4 1000000000 261710291 77697 12.27
enwik9 zstd 1 1000000000 358072021 3110 306.65
enwik9 zstd 3 1000000000 313734672 4784 199.35
enwik9 zstd 6 1000000000 295138875 10290 92.68
enwik9 zstd 9 1000000000 278348700 28549 33.40
enwik9 gzstd 1 1000000000 382578136 8608 110.78
enwik9 gzkp 1 1000000000 382781160 5628 169.45
Highly compressible JSON file.
https://files.klauspost.com/compress/github-june-2days-2019.json.zst
file out level insize outsize millis mb/s
github-june-2days-2019.json zskp 1 6273951764 697439532 9789 611.17
github-june-2days-2019.json zskp 2 6273951764 610876538 18553 322.49
github-june-2days-2019.json zskp 3 6273951764 517662858 44186 135.41
github-june-2days-2019.json zskp 4 6273951764 464617114 165373 36.18
github-june-2days-2019.json zstd 1 6273951764 766284037 8450 708.00
github-june-2days-2019.json zstd 3 6273951764 661889476 10927 547.57
github-june-2days-2019.json zstd 6 6273951764 642756859 22996 260.18
github-june-2days-2019.json zstd 9 6273951764 601974523 52413 114.16
github-june-2days-2019.json gzstd 1 6273951764 1164397768 26793 223.32
github-june-2days-2019.json gzkp 1 6273951764 1120631856 17693 338.16
VM Image, Linux mint with a few installed applications:
https://files.klauspost.com/compress/rawstudio-mint14.7z
file out level insize outsize millis mb/s
rawstudio-mint14.tar zskp 1 8558382592 3718400221 18206 448.29
rawstudio-mint14.tar zskp 2 8558382592 3326118337 37074 220.15
rawstudio-mint14.tar zskp 3 8558382592 3163842361 87306 93.49
rawstudio-mint14.tar zskp 4 8558382592 2970480650 783862 10.41
rawstudio-mint14.tar zstd 1 8558382592 3609250104 17136 476.27
rawstudio-mint14.tar zstd 3 8558382592 3341679997 29262 278.92
rawstudio-mint14.tar zstd 6 8558382592 3235846406 77904 104.77
rawstudio-mint14.tar zstd 9 8558382592 3160778861 140946 57.91
rawstudio-mint14.tar gzstd 1 8558382592 3926234992 51345 158.96
rawstudio-mint14.tar gzkp 1 8558382592 3960117298 36722 222.26
CSV data:
https://files.klauspost.com/compress/nyc-taxi-data-10M.csv.zst
file out level insize outsize millis mb/s
nyc-taxi-data-10M.csv zskp 1 3325605752 641319332 9462 335.17
nyc-taxi-data-10M.csv zskp 2 3325605752 588976126 17570 180.50
nyc-taxi-data-10M.csv zskp 3 3325605752 529329260 32432 97.79
nyc-taxi-data-10M.csv zskp 4 3325605752 474949772 138025 22.98
nyc-taxi-data-10M.csv zstd 1 3325605752 687399637 8233 385.18
nyc-taxi-data-10M.csv zstd 3 3325605752 598514411 10065 315.07
nyc-taxi-data-10M.csv zstd 6 3325605752 570522953 20038 158.27
nyc-taxi-data-10M.csv zstd 9 3325605752 517554797 64565 49.12
nyc-taxi-data-10M.csv gzstd 1 3325605752 928654908 21270 149.11
nyc-taxi-data-10M.csv gzkp 1 3325605752 922273214 13929 227.68
```
## Decompressor
Status: STABLE - there may still be subtle bugs, but a wide variety of content has been tested.
This library is being continuously [fuzz-tested](https://github.com/klauspost/compress-fuzz),
kindly supplied by [fuzzit.dev](https://fuzzit.dev/).
The main purpose of the fuzz testing is to ensure that it is not possible to crash the decoder,
or run it past its limits with ANY input provided.
### Usage
The package has been designed for two main usages, big streams of data and smaller in-memory buffers.
There are two main usages of the package for these. Both of them are accessed by creating a `Decoder`.
For streaming use a simple setup could look like this:
```Go
import "github.com/klauspost/compress/zstd"
func Decompress(in io.Reader, out io.Writer) error {
d, err := zstd.NewReader(in)
if err != nil {
return err
}
defer d.Close()
// Copy content...
_, err = io.Copy(out, d)
return err
}
```
It is important to use the "Close" function when you no longer need the Reader to stop running goroutines,
when running with default settings.
Goroutines will exit once an error has been returned, including `io.EOF` at the end of a stream.
Streams are decoded concurrently in 4 asynchronous stages to give the best possible throughput.
However, if you prefer synchronous decompression, use `WithDecoderConcurrency(1)` which will decompress data
as it is being requested only.
For decoding buffers, it could look something like this:
```Go
import "github.com/klauspost/compress/zstd"
// Create a reader that caches decompressors.
// For this operation type we supply a nil Reader.
var decoder, _ = zstd.NewReader(nil, zstd.WithDecoderConcurrency(0))
// Decompress a buffer. We don't supply a destination buffer,
// so it will be allocated by the decoder.
func Decompress(src []byte) ([]byte, error) {
return decoder.DecodeAll(src, nil)
}
```
Both of these cases should provide the functionality needed.
The decoder can be used for *concurrent* decompression of multiple buffers.
By default 4 decompressors will be created.
It will only allow a certain number of concurrent operations to run.
To tweak that yourself use the `WithDecoderConcurrency(n)` option when creating the decoder.
It is possible to use `WithDecoderConcurrency(0)` to create GOMAXPROCS decoders.
### Dictionaries
Data compressed with [dictionaries](https://github.com/facebook/zstd#the-case-for-small-data-compression) can be decompressed.
Dictionaries are added individually to Decoders.
Dictionaries are generated by the `zstd --train` command and contains an initial state for the decoder.
To add a dictionary use the `WithDecoderDicts(dicts ...[]byte)` option with the dictionary data.
Several dictionaries can be added at once.
The dictionary will be used automatically for the data that specifies them.
A re-used Decoder will still contain the dictionaries registered.
When registering multiple dictionaries with the same ID, the last one will be used.
It is possible to use dictionaries when compressing data.
To enable a dictionary use `WithEncoderDict(dict []byte)`. Here only one dictionary will be used
and it will likely be used even if it doesn't improve compression.
The used dictionary must be used to decompress the content.
For any real gains, the dictionary should be built with similar data.
If an unsuitable dictionary is used the output may be slightly larger than using no dictionary.
Use the [zstd commandline tool](https://github.com/facebook/zstd/releases) to build a dictionary from sample data.
For information see [zstd dictionary information](https://github.com/facebook/zstd#the-case-for-small-data-compression).
For now there is a fixed startup performance penalty for compressing content with dictionaries.
This will likely be improved over time. Just be aware to test performance when implementing.
### Allocation-less operation
The decoder has been designed to operate without allocations after a warmup.
This means that you should *store* the decoder for best performance.
To re-use a stream decoder, use the `Reset(r io.Reader) error` to switch to another stream.
A decoder can safely be re-used even if the previous stream failed.
To release the resources, you must call the `Close()` function on a decoder.
After this it can *no longer be reused*, but all running goroutines will be stopped.
So you *must* use this if you will no longer need the Reader.
For decompressing smaller buffers a single decoder can be used.
When decoding buffers, you can supply a destination slice with length 0 and your expected capacity.
In this case no unneeded allocations should be made.
### Concurrency
The buffer decoder does everything on the same goroutine and does nothing concurrently.
It can however decode several buffers concurrently. Use `WithDecoderConcurrency(n)` to limit that.
The stream decoder will create goroutines that:
1) Reads input and splits the input into blocks.
2) Decompression of literals.
3) Decompression of sequences.
4) Reconstruction of output stream.
So effectively this also means the decoder will "read ahead" and prepare data to always be available for output.
The concurrency level will, for streams, determine how many blocks ahead the compression will start.
Since "blocks" are quite dependent on the output of the previous block stream decoding will only have limited concurrency.
In practice this means that concurrency is often limited to utilizing about 3 cores effectively.
### Benchmarks
The first two are streaming decodes and the last are smaller inputs.
Running on AMD Ryzen 9 3950X 16-Core Processor. AMD64 assembly used.
```
BenchmarkDecoderSilesia-32 5 206878840 ns/op 1024.50 MB/s 49808 B/op 43 allocs/op
BenchmarkDecoderEnwik9-32 1 1271809000 ns/op 786.28 MB/s 72048 B/op 52 allocs/op
Concurrent blocks, performance:
BenchmarkDecoder_DecodeAllParallel/kppkn.gtb.zst-32 67356 17857 ns/op 10321.96 MB/s 22.48 pct 102 B/op 0 allocs/op
BenchmarkDecoder_DecodeAllParallel/geo.protodata.zst-32 266656 4421 ns/op 26823.21 MB/s 11.89 pct 19 B/op 0 allocs/op
BenchmarkDecoder_DecodeAllParallel/plrabn12.txt.zst-32 20992 56842 ns/op 8477.17 MB/s 39.90 pct 754 B/op 0 allocs/op
BenchmarkDecoder_DecodeAllParallel/lcet10.txt.zst-32 27456 43932 ns/op 9714.01 MB/s 33.27 pct 524 B/op 0 allocs/op
BenchmarkDecoder_DecodeAllParallel/asyoulik.txt.zst-32 78432 15047 ns/op 8319.15 MB/s 40.34 pct 66 B/op 0 allocs/op
BenchmarkDecoder_DecodeAllParallel/alice29.txt.zst-32 65800 18436 ns/op 8249.63 MB/s 37.75 pct 88 B/op 0 allocs/op
BenchmarkDecoder_DecodeAllParallel/html_x_4.zst-32 102993 11523 ns/op 35546.09 MB/s 3.637 pct 143 B/op 0 allocs/op
BenchmarkDecoder_DecodeAllParallel/paper-100k.pdf.zst-32 1000000 1070 ns/op 95720.98 MB/s 80.53 pct 3 B/op 0 allocs/op
BenchmarkDecoder_DecodeAllParallel/fireworks.jpeg.zst-32 749802 1752 ns/op 70272.35 MB/s 100.0 pct 5 B/op 0 allocs/op
BenchmarkDecoder_DecodeAllParallel/urls.10K.zst-32 22640 52934 ns/op 13263.37 MB/s 26.25 pct 1014 B/op 0 allocs/op
BenchmarkDecoder_DecodeAllParallel/html.zst-32 226412 5232 ns/op 19572.27 MB/s 14.49 pct 20 B/op 0 allocs/op
BenchmarkDecoder_DecodeAllParallel/comp-data.bin.zst-32 923041 1276 ns/op 3194.71 MB/s 31.26 pct 0 B/op 0 allocs/op
```
This reflects the performance around May 2022, but this may be out of date.
## Zstd inside ZIP files
It is possible to use zstandard to compress individual files inside zip archives.
While this isn't widely supported it can be useful for internal files.
To support the compression and decompression of these files you must register a compressor and decompressor.
It is highly recommended registering the (de)compressors on individual zip Reader/Writer and NOT
use the global registration functions. The main reason for this is that 2 registrations from
different packages will result in a panic.
It is a good idea to only have a single compressor and decompressor, since they can be used for multiple zip
files concurrently, and using a single instance will allow reusing some resources.
See [this example](https://pkg.go.dev/github.com/klauspost/compress/zstd#example-ZipCompressor) for
how to compress and decompress files inside zip archives.
# Contributions
Contributions are always welcome.
For new features/fixes, remember to add tests and for performance enhancements include benchmarks.
For general feedback and experience reports, feel free to open an issue or write me on [Twitter](https://twitter.com/sh0dan).
This package includes the excellent [`github.com/cespare/xxhash`](https://github.com/cespare/xxhash) package Copyright (c) 2016 Caleb Spare.
Server/vendor/github.com/klauspost/compress/zstd/bitreader.go
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+135
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@@ -0,0 +1,135 @@
// Copyright 2019+ Klaus Post. All rights reserved.
// License information can be found in the LICENSE file.
// Based on work by Yann Collet, released under BSD License.
package zstd
import (
"errors"
"fmt"
"io"
"math/bits"
"github.com/klauspost/compress/internal/le"
)
// bitReader reads a bitstream in reverse.
// The last set bit indicates the start of the stream and is used
// for aligning the input.
type bitReader struct {
in []byte
value uint64 // Maybe use [16]byte, but shifting is awkward.
cursor int // offset where next read should end
bitsRead uint8
}
// init initializes and resets the bit reader.
func (b *bitReader) init(in []byte) error {
if len(in) < 1 {
return errors.New("corrupt stream: too short")
}
b.in = in
// The highest bit of the last byte indicates where to start
v := in[len(in)-1]
if v == 0 {
return errors.New("corrupt stream, did not find end of stream")
}
b.cursor = len(in)
b.bitsRead = 64
b.value = 0
if len(in) >= 8 {
b.fillFastStart()
} else {
b.fill()
b.fill()
}
b.bitsRead += 8 - uint8(highBits(uint32(v)))
return nil
}
// getBits will return n bits. n can be 0.
func (b *bitReader) getBits(n uint8) int {
if n == 0 /*|| b.bitsRead >= 64 */ {
return 0
}
return int(b.get32BitsFast(n))
}
// get32BitsFast requires that at least one bit is requested every time.
// There are no checks if the buffer is filled.
func (b *bitReader) get32BitsFast(n uint8) uint32 {
const regMask = 64 - 1
v := uint32((b.value << (b.bitsRead & regMask)) >> ((regMask + 1 - n) & regMask))
b.bitsRead += n
return v
}
// fillFast() will make sure at least 32 bits are available.
// There must be at least 4 bytes available.
func (b *bitReader) fillFast() {
if b.bitsRead < 32 {
return
}
b.cursor -= 4
b.value = (b.value << 32) | uint64(le.Load32(b.in, b.cursor))
b.bitsRead -= 32
}
// fillFastStart() assumes the bitreader is empty and there is at least 8 bytes to read.
func (b *bitReader) fillFastStart() {
b.cursor -= 8
b.value = le.Load64(b.in, b.cursor)
b.bitsRead = 0
}
// fill() will make sure at least 32 bits are available.
func (b *bitReader) fill() {
if b.bitsRead < 32 {
return
}
if b.cursor >= 4 {
b.cursor -= 4
b.value = (b.value << 32) | uint64(le.Load32(b.in, b.cursor))
b.bitsRead -= 32
return
}
b.bitsRead -= uint8(8 * b.cursor)
for b.cursor > 0 {
b.cursor -= 1
b.value = (b.value << 8) | uint64(b.in[b.cursor])
}
}
// finished returns true if all bits have been read from the bit stream.
func (b *bitReader) finished() bool {
return b.cursor == 0 && b.bitsRead >= 64
}
// overread returns true if more bits have been requested than is on the stream.
func (b *bitReader) overread() bool {
return b.bitsRead > 64
}
// remain returns the number of bits remaining.
func (b *bitReader) remain() uint {
return 8*uint(b.cursor) + 64 - uint(b.bitsRead)
}
// close the bitstream and returns an error if out-of-buffer reads occurred.
func (b *bitReader) close() error {
// Release reference.
b.in = nil
b.cursor = 0
if !b.finished() {
return fmt.Errorf("%d extra bits on block, should be 0", b.remain())
}
if b.bitsRead > 64 {
return io.ErrUnexpectedEOF
}
return nil
}
func highBits(val uint32) (n uint32) {
return uint32(bits.Len32(val) - 1)
}
Server/vendor/github.com/klauspost/compress/zstd/bitwriter.go
Generated Vendored
+112
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@@ -0,0 +1,112 @@
// Copyright 2018 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
package zstd
// bitWriter will write bits.
// First bit will be LSB of the first byte of output.
type bitWriter struct {
bitContainer uint64
nBits uint8
out []byte
}
// bitMask16 is bitmasks. Has extra to avoid bounds check.
var bitMask16 = [32]uint16{
0, 1, 3, 7, 0xF, 0x1F,
0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF,
0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF, 0xFFFF,
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
0xFFFF, 0xFFFF} /* up to 16 bits */
var bitMask32 = [32]uint32{
0, 1, 3, 7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF,
0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF,
0x1ffff, 0x3ffff, 0x7FFFF, 0xfFFFF, 0x1fFFFF, 0x3fFFFF, 0x7fFFFF, 0xffFFFF,
0x1ffFFFF, 0x3ffFFFF, 0x7ffFFFF, 0xfffFFFF, 0x1fffFFFF, 0x3fffFFFF, 0x7fffFFFF,
} // up to 32 bits
// addBits16NC will add up to 16 bits.
// It will not check if there is space for them,
// so the caller must ensure that it has flushed recently.
func (b *bitWriter) addBits16NC(value uint16, bits uint8) {
b.bitContainer |= uint64(value&bitMask16[bits&31]) << (b.nBits & 63)
b.nBits += bits
}
// addBits32NC will add up to 31 bits.
// It will not check if there is space for them,
// so the caller must ensure that it has flushed recently.
func (b *bitWriter) addBits32NC(value uint32, bits uint8) {
b.bitContainer |= uint64(value&bitMask32[bits&31]) << (b.nBits & 63)
b.nBits += bits
}
// addBits64NC will add up to 64 bits.
// There must be space for 32 bits.
func (b *bitWriter) addBits64NC(value uint64, bits uint8) {
if bits <= 31 {
b.addBits32Clean(uint32(value), bits)
return
}
b.addBits32Clean(uint32(value), 32)
b.flush32()
b.addBits32Clean(uint32(value>>32), bits-32)
}
// addBits32Clean will add up to 32 bits.
// It will not check if there is space for them.
// The input must not contain more bits than specified.
func (b *bitWriter) addBits32Clean(value uint32, bits uint8) {
b.bitContainer |= uint64(value) << (b.nBits & 63)
b.nBits += bits
}
// addBits16Clean will add up to 16 bits. value may not contain more set bits than indicated.
// It will not check if there is space for them, so the caller must ensure that it has flushed recently.
func (b *bitWriter) addBits16Clean(value uint16, bits uint8) {
b.bitContainer |= uint64(value) << (b.nBits & 63)
b.nBits += bits
}
// flush32 will flush out, so there are at least 32 bits available for writing.
func (b *bitWriter) flush32() {
if b.nBits < 32 {
return
}
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
byte(b.bitContainer>>24))
b.nBits -= 32
b.bitContainer >>= 32
}
// flushAlign will flush remaining full bytes and align to next byte boundary.
func (b *bitWriter) flushAlign() {
nbBytes := (b.nBits + 7) >> 3
for i := range nbBytes {
b.out = append(b.out, byte(b.bitContainer>>(i*8)))
}
b.nBits = 0
b.bitContainer = 0
}
// close will write the alignment bit and write the final byte(s)
// to the output.
func (b *bitWriter) close() {
// End mark
b.addBits16Clean(1, 1)
// flush until next byte.
b.flushAlign()
}
// reset and continue writing by appending to out.
func (b *bitWriter) reset(out []byte) {
b.bitContainer = 0
b.nBits = 0
b.out = out
}
Server/vendor/github.com/klauspost/compress/zstd/blockdec.go
Generated Vendored
+712
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@@ -0,0 +1,712 @@
// Copyright 2019+ Klaus Post. All rights reserved.
// License information can be found in the LICENSE file.
// Based on work by Yann Collet, released under BSD License.
package zstd
import (
"errors"
"fmt"
"hash/crc32"
"io"
"sync"
"github.com/klauspost/compress/huff0"
"github.com/klauspost/compress/zstd/internal/xxhash"
)
type blockType uint8
//go:generate stringer -type=blockType,literalsBlockType,seqCompMode,tableIndex
const (
blockTypeRaw blockType = iota
blockTypeRLE
blockTypeCompressed
blockTypeReserved
)
type literalsBlockType uint8
const (
literalsBlockRaw literalsBlockType = iota
literalsBlockRLE
literalsBlockCompressed
literalsBlockTreeless
)
const (
// maxCompressedBlockSize is the biggest allowed compressed block size (128KB)
maxCompressedBlockSize = 128 << 10
compressedBlockOverAlloc = 16
maxCompressedBlockSizeAlloc = 128<<10 + compressedBlockOverAlloc
// Maximum possible block size (all Raw+Uncompressed).
maxBlockSize = (1 << 21) - 1
maxMatchLen = 131074
maxSequences = 0x7f00 + 0xffff
// We support slightly less than the reference decoder to be able to
// use ints on 32 bit archs.
maxOffsetBits = 30
)
var (
huffDecoderPool = sync.Pool{New: func() any {
return &huff0.Scratch{}
}}
fseDecoderPool = sync.Pool{New: func() any {
return &fseDecoder{}
}}
)
type blockDec struct {
// Raw source data of the block.
data []byte
dataStorage []byte
// Destination of the decoded data.
dst []byte
// Buffer for literals data.
literalBuf []byte
// Window size of the block.
WindowSize uint64
err error
// Check against this crc, if hasCRC is true.
checkCRC uint32
hasCRC bool
// Frame to use for singlethreaded decoding.
// Should not be used by the decoder itself since parent may be another frame.
localFrame *frameDec
sequence []seqVals
async struct {
newHist *history
literals []byte
seqData []byte
seqSize int // Size of uncompressed sequences
fcs uint64
}
// Block is RLE, this is the size.
RLESize uint32
Type blockType
// Is this the last block of a frame?
Last bool
// Use less memory
lowMem bool
}
func (b *blockDec) String() string {
if b == nil {
return "<nil>"
}
return fmt.Sprintf("Steam Size: %d, Type: %v, Last: %t, Window: %d", len(b.data), b.Type, b.Last, b.WindowSize)
}
func newBlockDec(lowMem bool) *blockDec {
b := blockDec{
lowMem: lowMem,
}
return &b
}
// reset will reset the block.
// Input must be a start of a block and will be at the end of the block when returned.
func (b *blockDec) reset(br byteBuffer, windowSize uint64) error {
b.WindowSize = windowSize
tmp, err := br.readSmall(3)
if err != nil {
println("Reading block header:", err)
return err
}
bh := uint32(tmp[0]) | (uint32(tmp[1]) << 8) | (uint32(tmp[2]) << 16)
b.Last = bh&1 != 0
b.Type = blockType((bh >> 1) & 3)
// find size.
cSize := int(bh >> 3)
maxSize := maxCompressedBlockSizeAlloc
switch b.Type {
case blockTypeReserved:
return ErrReservedBlockType
case blockTypeRLE:
if cSize > maxCompressedBlockSize || cSize > int(b.WindowSize) {
if debugDecoder {
printf("rle block too big: csize:%d block: %+v\n", uint64(cSize), b)
}
return ErrWindowSizeExceeded
}
b.RLESize = uint32(cSize)
if b.lowMem {
maxSize = cSize
}
cSize = 1
case blockTypeCompressed:
if debugDecoder {
println("Data size on stream:", cSize)
}
b.RLESize = 0
maxSize = maxCompressedBlockSizeAlloc
if windowSize < maxCompressedBlockSize && b.lowMem {
maxSize = int(windowSize) + compressedBlockOverAlloc
}
if cSize > maxCompressedBlockSize || uint64(cSize) > b.WindowSize {
if debugDecoder {
printf("compressed block too big: csize:%d block: %+v\n", uint64(cSize), b)
}
return ErrCompressedSizeTooBig
}
// Empty compressed blocks must at least be 2 bytes
// for Literals_Block_Type and one for Sequences_Section_Header.
if cSize < 2 {
return ErrBlockTooSmall
}
case blockTypeRaw:
if cSize > maxCompressedBlockSize || cSize > int(b.WindowSize) {
if debugDecoder {
printf("rle block too big: csize:%d block: %+v\n", uint64(cSize), b)
}
return ErrWindowSizeExceeded
}
b.RLESize = 0
// We do not need a destination for raw blocks.
maxSize = -1
default:
panic("Invalid block type")
}
// Read block data.
if _, ok := br.(*byteBuf); !ok && cap(b.dataStorage) < cSize {
// byteBuf doesn't need a destination buffer.
if b.lowMem || cSize > maxCompressedBlockSize {
b.dataStorage = make([]byte, 0, cSize+compressedBlockOverAlloc)
} else {
b.dataStorage = make([]byte, 0, maxCompressedBlockSizeAlloc)
}
}
b.data, err = br.readBig(cSize, b.dataStorage)
if err != nil {
if debugDecoder {
println("Reading block:", err, "(", cSize, ")", len(b.data))
printf("%T", br)
}
return err
}
if cap(b.dst) <= maxSize {
b.dst = make([]byte, 0, maxSize+1)
}
return nil
}
// sendEOF will make the decoder send EOF on this frame.
func (b *blockDec) sendErr(err error) {
b.Last = true
b.Type = blockTypeReserved
b.err = err
}
// Close will release resources.
// Closed blockDec cannot be reset.
func (b *blockDec) Close() {
}
// decodeBuf
func (b *blockDec) decodeBuf(hist *history) error {
switch b.Type {
case blockTypeRLE:
if cap(b.dst) < int(b.RLESize) {
if b.lowMem {
b.dst = make([]byte, b.RLESize)
} else {
b.dst = make([]byte, maxCompressedBlockSize)
}
}
b.dst = b.dst[:b.RLESize]
v := b.data[0]
for i := range b.dst {
b.dst[i] = v
}
hist.appendKeep(b.dst)
return nil
case blockTypeRaw:
hist.appendKeep(b.data)
return nil
case blockTypeCompressed:
saved := b.dst
// Append directly to history
if hist.ignoreBuffer == 0 {
b.dst = hist.b
hist.b = nil
} else {
b.dst = b.dst[:0]
}
err := b.decodeCompressed(hist)
if debugDecoder {
println("Decompressed to total", len(b.dst), "bytes, hash:", xxhash.Sum64(b.dst), "error:", err)
}
if hist.ignoreBuffer == 0 {
hist.b = b.dst
b.dst = saved
} else {
hist.appendKeep(b.dst)
}
return err
case blockTypeReserved:
// Used for returning errors.
return b.err
default:
panic("Invalid block type")
}
}
func (b *blockDec) decodeLiterals(in []byte, hist *history) (remain []byte, err error) {
// There must be at least one byte for Literals_Block_Type and one for Sequences_Section_Header
if len(in) < 2 {
return in, ErrBlockTooSmall
}
litType := literalsBlockType(in[0] & 3)
var litRegenSize int
var litCompSize int
sizeFormat := (in[0] >> 2) & 3
var fourStreams bool
var literals []byte
switch litType {
case literalsBlockRaw, literalsBlockRLE:
switch sizeFormat {
case 0, 2:
// Regenerated_Size uses 5 bits (0-31). Literals_Section_Header uses 1 byte.
litRegenSize = int(in[0] >> 3)
in = in[1:]
case 1:
// Regenerated_Size uses 12 bits (0-4095). Literals_Section_Header uses 2 bytes.
litRegenSize = int(in[0]>>4) + (int(in[1]) << 4)
in = in[2:]
case 3:
// Regenerated_Size uses 20 bits (0-1048575). Literals_Section_Header uses 3 bytes.
if len(in) < 3 {
println("too small: litType:", litType, " sizeFormat", sizeFormat, len(in))
return in, ErrBlockTooSmall
}
litRegenSize = int(in[0]>>4) + (int(in[1]) << 4) + (int(in[2]) << 12)
in = in[3:]
}
case literalsBlockCompressed, literalsBlockTreeless:
switch sizeFormat {
case 0, 1:
// Both Regenerated_Size and Compressed_Size use 10 bits (0-1023).
if len(in) < 3 {
println("too small: litType:", litType, " sizeFormat", sizeFormat, len(in))
return in, ErrBlockTooSmall
}
n := uint64(in[0]>>4) + (uint64(in[1]) << 4) + (uint64(in[2]) << 12)
litRegenSize = int(n & 1023)
litCompSize = int(n >> 10)
fourStreams = sizeFormat == 1
in = in[3:]
case 2:
fourStreams = true
if len(in) < 4 {
println("too small: litType:", litType, " sizeFormat", sizeFormat, len(in))
return in, ErrBlockTooSmall
}
n := uint64(in[0]>>4) + (uint64(in[1]) << 4) + (uint64(in[2]) << 12) + (uint64(in[3]) << 20)
litRegenSize = int(n & 16383)
litCompSize = int(n >> 14)
in = in[4:]
case 3:
fourStreams = true
if len(in) < 5 {
println("too small: litType:", litType, " sizeFormat", sizeFormat, len(in))
return in, ErrBlockTooSmall
}
n := uint64(in[0]>>4) + (uint64(in[1]) << 4) + (uint64(in[2]) << 12) + (uint64(in[3]) << 20) + (uint64(in[4]) << 28)
litRegenSize = int(n & 262143)
litCompSize = int(n >> 18)
in = in[5:]
}
}
if debugDecoder {
println("literals type:", litType, "litRegenSize:", litRegenSize, "litCompSize:", litCompSize, "sizeFormat:", sizeFormat, "4X:", fourStreams)
}
if litRegenSize > int(b.WindowSize) || litRegenSize > maxCompressedBlockSize {
return in, ErrWindowSizeExceeded
}
switch litType {
case literalsBlockRaw:
if len(in) < litRegenSize {
println("too small: litType:", litType, " sizeFormat", sizeFormat, "remain:", len(in), "want:", litRegenSize)
return in, ErrBlockTooSmall
}
literals = in[:litRegenSize]
in = in[litRegenSize:]
//printf("Found %d uncompressed literals\n", litRegenSize)
case literalsBlockRLE:
if len(in) < 1 {
println("too small: litType:", litType, " sizeFormat", sizeFormat, "remain:", len(in), "want:", 1)
return in, ErrBlockTooSmall
}
if cap(b.literalBuf) < litRegenSize {
if b.lowMem {
b.literalBuf = make([]byte, litRegenSize, litRegenSize+compressedBlockOverAlloc)
} else {
b.literalBuf = make([]byte, litRegenSize, maxCompressedBlockSize+compressedBlockOverAlloc)
}
}
literals = b.literalBuf[:litRegenSize]
v := in[0]
for i := range literals {
literals[i] = v
}
in = in[1:]
if debugDecoder {
printf("Found %d RLE compressed literals\n", litRegenSize)
}
case literalsBlockTreeless:
if len(in) < litCompSize {
println("too small: litType:", litType, " sizeFormat", sizeFormat, "remain:", len(in), "want:", litCompSize)
return in, ErrBlockTooSmall
}
// Store compressed literals, so we defer decoding until we get history.
literals = in[:litCompSize]
in = in[litCompSize:]
if debugDecoder {
printf("Found %d compressed literals\n", litCompSize)
}
huff := hist.huffTree
if huff == nil {
return in, errors.New("literal block was treeless, but no history was defined")
}
// Ensure we have space to store it.
if cap(b.literalBuf) < litRegenSize {
if b.lowMem {
b.literalBuf = make([]byte, 0, litRegenSize+compressedBlockOverAlloc)
} else {
b.literalBuf = make([]byte, 0, maxCompressedBlockSize+compressedBlockOverAlloc)
}
}
var err error
// Use our out buffer.
huff.MaxDecodedSize = litRegenSize
if fourStreams {
literals, err = huff.Decoder().Decompress4X(b.literalBuf[:0:litRegenSize], literals)
} else {
literals, err = huff.Decoder().Decompress1X(b.literalBuf[:0:litRegenSize], literals)
}
// Make sure we don't leak our literals buffer
if err != nil {
println("decompressing literals:", err)
return in, err
}
if len(literals) != litRegenSize {
return in, fmt.Errorf("literal output size mismatch want %d, got %d", litRegenSize, len(literals))
}
case literalsBlockCompressed:
if len(in) < litCompSize {
println("too small: litType:", litType, " sizeFormat", sizeFormat, "remain:", len(in), "want:", litCompSize)
return in, ErrBlockTooSmall
}
literals = in[:litCompSize]
in = in[litCompSize:]
// Ensure we have space to store it.
if cap(b.literalBuf) < litRegenSize {
if b.lowMem {
b.literalBuf = make([]byte, 0, litRegenSize+compressedBlockOverAlloc)
} else {
b.literalBuf = make([]byte, 0, maxCompressedBlockSize+compressedBlockOverAlloc)
}
}
huff := hist.huffTree
if huff == nil || (hist.dict != nil && huff == hist.dict.litEnc) {
huff = huffDecoderPool.Get().(*huff0.Scratch)
if huff == nil {
huff = &huff0.Scratch{}
}
}
var err error
if debugDecoder {
println("huff table input:", len(literals), "CRC:", crc32.ChecksumIEEE(literals))
}
huff, literals, err = huff0.ReadTable(literals, huff)
if err != nil {
println("reading huffman table:", err)
return in, err
}
hist.huffTree = huff
huff.MaxDecodedSize = litRegenSize
// Use our out buffer.
if fourStreams {
literals, err = huff.Decoder().Decompress4X(b.literalBuf[:0:litRegenSize], literals)
} else {
literals, err = huff.Decoder().Decompress1X(b.literalBuf[:0:litRegenSize], literals)
}
if err != nil {
println("decoding compressed literals:", err)
return in, err
}
// Make sure we don't leak our literals buffer
if len(literals) != litRegenSize {
return in, fmt.Errorf("literal output size mismatch want %d, got %d", litRegenSize, len(literals))
}
// Re-cap to get extra size.
literals = b.literalBuf[:len(literals)]
if debugDecoder {
printf("Decompressed %d literals into %d bytes\n", litCompSize, litRegenSize)
}
}
hist.decoders.literals = literals
return in, nil
}
// decodeCompressed will start decompressing a block.
func (b *blockDec) decodeCompressed(hist *history) error {
in := b.data
in, err := b.decodeLiterals(in, hist)
if err != nil {
return err
}
err = b.prepareSequences(in, hist)
if err != nil {
return err
}
if hist.decoders.nSeqs == 0 {
b.dst = append(b.dst, hist.decoders.literals...)
return nil
}
before := len(hist.decoders.out)
err = hist.decoders.decodeSync(hist.b[hist.ignoreBuffer:])
if err != nil {
return err
}
if hist.decoders.maxSyncLen > 0 {
hist.decoders.maxSyncLen += uint64(before)
hist.decoders.maxSyncLen -= uint64(len(hist.decoders.out))
}
b.dst = hist.decoders.out
hist.recentOffsets = hist.decoders.prevOffset
return nil
}
func (b *blockDec) prepareSequences(in []byte, hist *history) (err error) {
if debugDecoder {
printf("prepareSequences: %d byte(s) input\n", len(in))
}
// Decode Sequences
// https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#sequences-section
if len(in) < 1 {
return ErrBlockTooSmall
}
var nSeqs int
seqHeader := in[0]
switch {
case seqHeader < 128:
nSeqs = int(seqHeader)
in = in[1:]
case seqHeader < 255:
if len(in) < 2 {
return ErrBlockTooSmall
}
nSeqs = int(seqHeader-128)<<8 | int(in[1])
in = in[2:]
case seqHeader == 255:
if len(in) < 3 {
return ErrBlockTooSmall
}
nSeqs = 0x7f00 + int(in[1]) + (int(in[2]) << 8)
in = in[3:]
}
if nSeqs == 0 && len(in) != 0 {
// When no sequences, there should not be any more data...
if debugDecoder {
printf("prepareSequences: 0 sequences, but %d byte(s) left on stream\n", len(in))
}
return ErrUnexpectedBlockSize
}
var seqs = &hist.decoders
seqs.nSeqs = nSeqs
if nSeqs > 0 {
if len(in) < 1 {
return ErrBlockTooSmall
}
br := byteReader{b: in, off: 0}
compMode := br.Uint8()
br.advance(1)
if debugDecoder {
printf("Compression modes: 0b%b", compMode)
}
if compMode&3 != 0 {
return errors.New("corrupt block: reserved bits not zero")
}
for i := range uint(3) {
mode := seqCompMode((compMode >> (6 - i*2)) & 3)
if debugDecoder {
println("Table", tableIndex(i), "is", mode)
}
var seq *sequenceDec
switch tableIndex(i) {
case tableLiteralLengths:
seq = &seqs.litLengths
case tableOffsets:
seq = &seqs.offsets
case tableMatchLengths:
seq = &seqs.matchLengths
default:
panic("unknown table")
}
switch mode {
case compModePredefined:
if seq.fse != nil && !seq.fse.preDefined {
fseDecoderPool.Put(seq.fse)
}
seq.fse = &fsePredef[i]
case compModeRLE:
if br.remain() < 1 {
return ErrBlockTooSmall
}
v := br.Uint8()
br.advance(1)
if seq.fse == nil || seq.fse.preDefined {
seq.fse = fseDecoderPool.Get().(*fseDecoder)
}
symb, err := decSymbolValue(v, symbolTableX[i])
if err != nil {
printf("RLE Transform table (%v) error: %v", tableIndex(i), err)
return err
}
seq.fse.setRLE(symb)
if debugDecoder {
printf("RLE set to 0x%x, code: %v", symb, v)
}
case compModeFSE:
if debugDecoder {
println("Reading table for", tableIndex(i))
}
if seq.fse == nil || seq.fse.preDefined {
seq.fse = fseDecoderPool.Get().(*fseDecoder)
}
err := seq.fse.readNCount(&br, uint16(maxTableSymbol[i]))
if err != nil {
println("Read table error:", err)
return err
}
err = seq.fse.transform(symbolTableX[i])
if err != nil {
println("Transform table error:", err)
return err
}
if debugDecoder {
println("Read table ok", "symbolLen:", seq.fse.symbolLen)
}
case compModeRepeat:
seq.repeat = true
}
if br.overread() {
return io.ErrUnexpectedEOF
}
}
in = br.unread()
}
if debugDecoder {
println("Literals:", len(seqs.literals), "hash:", xxhash.Sum64(seqs.literals), "and", seqs.nSeqs, "sequences.")
}
if nSeqs == 0 {
if len(b.sequence) > 0 {
b.sequence = b.sequence[:0]
}
return nil
}
br := seqs.br
if br == nil {
br = &bitReader{}
}
if err := br.init(in); err != nil {
return err
}
if err := seqs.initialize(br, hist, b.dst); err != nil {
println("initializing sequences:", err)
return err
}
return nil
}
func (b *blockDec) decodeSequences(hist *history) error {
if cap(b.sequence) < hist.decoders.nSeqs {
if b.lowMem {
b.sequence = make([]seqVals, 0, hist.decoders.nSeqs)
} else {
b.sequence = make([]seqVals, 0, 0x7F00+0xffff)
}
}
b.sequence = b.sequence[:hist.decoders.nSeqs]
if hist.decoders.nSeqs == 0 {
hist.decoders.seqSize = len(hist.decoders.literals)
return nil
}
hist.decoders.windowSize = hist.windowSize
hist.decoders.prevOffset = hist.recentOffsets
err := hist.decoders.decode(b.sequence)
hist.recentOffsets = hist.decoders.prevOffset
return err
}
func (b *blockDec) executeSequences(hist *history) error {
hbytes := hist.b
if len(hbytes) > hist.windowSize {
hbytes = hbytes[len(hbytes)-hist.windowSize:]
// We do not need history anymore.
if hist.dict != nil {
hist.dict.content = nil
}
}
hist.decoders.windowSize = hist.windowSize
hist.decoders.out = b.dst[:0]
err := hist.decoders.execute(b.sequence, hbytes)
if err != nil {
return err
}
return b.updateHistory(hist)
}
func (b *blockDec) updateHistory(hist *history) error {
if len(b.data) > maxCompressedBlockSize {
return fmt.Errorf("compressed block size too large (%d)", len(b.data))
}
// Set output and release references.
b.dst = hist.decoders.out
hist.recentOffsets = hist.decoders.prevOffset
if b.Last {
// if last block we don't care about history.
println("Last block, no history returned")
hist.b = hist.b[:0]
return nil
} else {
hist.append(b.dst)
if debugDecoder {
println("Finished block with ", len(b.sequence), "sequences. Added", len(b.dst), "to history, now length", len(hist.b))
}
}
hist.decoders.out, hist.decoders.literals = nil, nil
return nil
}
Server/vendor/github.com/klauspost/compress/zstd/blockenc.go
Generated Vendored
+893
View File
@@ -0,0 +1,893 @@
// Copyright 2019+ Klaus Post. All rights reserved.
// License information can be found in the LICENSE file.
// Based on work by Yann Collet, released under BSD License.
package zstd
import (
"errors"
"fmt"
"math"
"math/bits"
"slices"
"github.com/klauspost/compress/huff0"
)
type blockEnc struct {
size int
literals []byte
sequences []seq
coders seqCoders
litEnc *huff0.Scratch
dictLitEnc *huff0.Scratch
wr bitWriter
extraLits int
output []byte
recentOffsets [3]uint32
prevRecentOffsets [3]uint32
last bool
lowMem bool
}
// init should be used once the block has been created.
// If called more than once, the effect is the same as calling reset.
func (b *blockEnc) init() {
if b.lowMem {
// 1K literals
if cap(b.literals) < 1<<10 {
b.literals = make([]byte, 0, 1<<10)
}
const defSeqs = 20
if cap(b.sequences) < defSeqs {
b.sequences = make([]seq, 0, defSeqs)
}
// 1K
if cap(b.output) < 1<<10 {
b.output = make([]byte, 0, 1<<10)
}
} else {
if cap(b.literals) < maxCompressedBlockSize {
b.literals = make([]byte, 0, maxCompressedBlockSize)
}
const defSeqs = 2000
if cap(b.sequences) < defSeqs {
b.sequences = make([]seq, 0, defSeqs)
}
if cap(b.output) < maxCompressedBlockSize {
b.output = make([]byte, 0, maxCompressedBlockSize)
}
}
if b.coders.mlEnc == nil {
b.coders.mlEnc = &fseEncoder{}
b.coders.mlPrev = &fseEncoder{}
b.coders.ofEnc = &fseEncoder{}
b.coders.ofPrev = &fseEncoder{}
b.coders.llEnc = &fseEncoder{}
b.coders.llPrev = &fseEncoder{}
}
b.litEnc = &huff0.Scratch{WantLogLess: 4}
b.reset(nil)
}
// initNewEncode can be used to reset offsets and encoders to the initial state.
func (b *blockEnc) initNewEncode() {
b.recentOffsets = [3]uint32{1, 4, 8}
b.litEnc.Reuse = huff0.ReusePolicyNone
b.coders.setPrev(nil, nil, nil)
b.dictLitEnc = nil
}
// reset will reset the block for a new encode, but in the same stream,
// meaning that state will be carried over, but the block content is reset.
// If a previous block is provided, the recent offsets are carried over.
func (b *blockEnc) reset(prev *blockEnc) {
b.extraLits = 0
b.literals = b.literals[:0]
b.size = 0
b.sequences = b.sequences[:0]
b.output = b.output[:0]
b.last = false
if prev != nil {
b.recentOffsets = prev.prevRecentOffsets
}
b.dictLitEnc = nil
}
// reset will reset the block for a new encode, but in the same stream,
// meaning that state will be carried over, but the block content is reset.
// If a previous block is provided, the recent offsets are carried over.
func (b *blockEnc) swapEncoders(prev *blockEnc) {
b.coders.swap(&prev.coders)
b.litEnc, prev.litEnc = prev.litEnc, b.litEnc
}
// blockHeader contains the information for a block header.
type blockHeader uint32
// setLast sets the 'last' indicator on a block.
func (h *blockHeader) setLast(b bool) {
if b {
*h = *h | 1
} else {
const mask = (1 << 24) - 2
*h = *h & mask
}
}
// setSize will store the compressed size of a block.
func (h *blockHeader) setSize(v uint32) {
const mask = 7
*h = (*h)&mask | blockHeader(v<<3)
}
// setType sets the block type.
func (h *blockHeader) setType(t blockType) {
const mask = 1 | (((1 << 24) - 1) ^ 7)
*h = (*h & mask) | blockHeader(t<<1)
}
// appendTo will append the block header to a slice.
func (h blockHeader) appendTo(b []byte) []byte {
return append(b, uint8(h), uint8(h>>8), uint8(h>>16))
}
// String returns a string representation of the block.
func (h blockHeader) String() string {
return fmt.Sprintf("Type: %d, Size: %d, Last:%t", (h>>1)&3, h>>3, h&1 == 1)
}
// literalsHeader contains literals header information.
type literalsHeader uint64
// setType can be used to set the type of literal block.
func (h *literalsHeader) setType(t literalsBlockType) {
const mask = math.MaxUint64 - 3
*h = (*h & mask) | literalsHeader(t)
}
// setSize can be used to set a single size, for uncompressed and RLE content.
func (h *literalsHeader) setSize(regenLen int) {
inBits := bits.Len32(uint32(regenLen))
// Only retain 2 bits
const mask = 3
lh := uint64(*h & mask)
switch {
case inBits < 5:
lh |= (uint64(regenLen) << 3) | (1 << 60)
if debugEncoder {
got := int(lh>>3) & 0xff
if got != regenLen {
panic(fmt.Sprint("litRegenSize = ", regenLen, "(want) != ", got, "(got)"))
}
}
case inBits < 12:
lh |= (1 << 2) | (uint64(regenLen) << 4) | (2 << 60)
case inBits < 20:
lh |= (3 << 2) | (uint64(regenLen) << 4) | (3 << 60)
default:
panic(fmt.Errorf("internal error: block too big (%d)", regenLen))
}
*h = literalsHeader(lh)
}
// setSizes will set the size of a compressed literals section and the input length.
func (h *literalsHeader) setSizes(compLen, inLen int, single bool) {
compBits, inBits := bits.Len32(uint32(compLen)), bits.Len32(uint32(inLen))
// Only retain 2 bits
const mask = 3
lh := uint64(*h & mask)
switch {
case compBits <= 10 && inBits <= 10:
if !single {
lh |= 1 << 2
}
lh |= (uint64(inLen) << 4) | (uint64(compLen) << (10 + 4)) | (3 << 60)
if debugEncoder {
const mmask = (1 << 24) - 1
n := (lh >> 4) & mmask
if int(n&1023) != inLen {
panic(fmt.Sprint("regensize:", int(n&1023), "!=", inLen, inBits))
}
if int(n>>10) != compLen {
panic(fmt.Sprint("compsize:", int(n>>10), "!=", compLen, compBits))
}
}
case compBits <= 14 && inBits <= 14:
lh |= (2 << 2) | (uint64(inLen) << 4) | (uint64(compLen) << (14 + 4)) | (4 << 60)
if single {
panic("single stream used with more than 10 bits length.")
}
case compBits <= 18 && inBits <= 18:
lh |= (3 << 2) | (uint64(inLen) << 4) | (uint64(compLen) << (18 + 4)) | (5 << 60)
if single {
panic("single stream used with more than 10 bits length.")
}
default:
panic("internal error: block too big")
}
*h = literalsHeader(lh)
}
// appendTo will append the literals header to a byte slice.
func (h literalsHeader) appendTo(b []byte) []byte {
size := uint8(h >> 60)
switch size {
case 1:
b = append(b, uint8(h))
case 2:
b = append(b, uint8(h), uint8(h>>8))
case 3:
b = append(b, uint8(h), uint8(h>>8), uint8(h>>16))
case 4:
b = append(b, uint8(h), uint8(h>>8), uint8(h>>16), uint8(h>>24))
case 5:
b = append(b, uint8(h), uint8(h>>8), uint8(h>>16), uint8(h>>24), uint8(h>>32))
default:
panic(fmt.Errorf("internal error: literalsHeader has invalid size (%d)", size))
}
return b
}
// size returns the output size with currently set values.
func (h literalsHeader) size() int {
return int(h >> 60)
}
func (h literalsHeader) String() string {
return fmt.Sprintf("Type: %d, SizeFormat: %d, Size: 0x%d, Bytes:%d", literalsBlockType(h&3), (h>>2)&3, h&((1<<60)-1)>>4, h>>60)
}
// pushOffsets will push the recent offsets to the backup store.
func (b *blockEnc) pushOffsets() {
b.prevRecentOffsets = b.recentOffsets
}
// pushOffsets will push the recent offsets to the backup store.
func (b *blockEnc) popOffsets() {
b.recentOffsets = b.prevRecentOffsets
}
// matchOffset will adjust recent offsets and return the adjusted one,
// if it matches a previous offset.
func (b *blockEnc) matchOffset(offset, lits uint32) uint32 {
// Check if offset is one of the recent offsets.
// Adjusts the output offset accordingly.
// Gives a tiny bit of compression, typically around 1%.
if true {
if lits > 0 {
switch offset {
case b.recentOffsets[0]:
offset = 1
case b.recentOffsets[1]:
b.recentOffsets[1] = b.recentOffsets[0]
b.recentOffsets[0] = offset
offset = 2
case b.recentOffsets[2]:
b.recentOffsets[2] = b.recentOffsets[1]
b.recentOffsets[1] = b.recentOffsets[0]
b.recentOffsets[0] = offset
offset = 3
default:
b.recentOffsets[2] = b.recentOffsets[1]
b.recentOffsets[1] = b.recentOffsets[0]
b.recentOffsets[0] = offset
offset += 3
}
} else {
switch offset {
case b.recentOffsets[1]:
b.recentOffsets[1] = b.recentOffsets[0]
b.recentOffsets[0] = offset
offset = 1
case b.recentOffsets[2]:
b.recentOffsets[2] = b.recentOffsets[1]
b.recentOffsets[1] = b.recentOffsets[0]
b.recentOffsets[0] = offset
offset = 2
case b.recentOffsets[0] - 1:
b.recentOffsets[2] = b.recentOffsets[1]
b.recentOffsets[1] = b.recentOffsets[0]
b.recentOffsets[0] = offset
offset = 3
default:
b.recentOffsets[2] = b.recentOffsets[1]
b.recentOffsets[1] = b.recentOffsets[0]
b.recentOffsets[0] = offset
offset += 3
}
}
} else {
offset += 3
}
return offset
}
// encodeRaw can be used to set the output to a raw representation of supplied bytes.
func (b *blockEnc) encodeRaw(a []byte) {
var bh blockHeader
bh.setLast(b.last)
bh.setSize(uint32(len(a)))
bh.setType(blockTypeRaw)
b.output = bh.appendTo(b.output[:0])
b.output = append(b.output, a...)
if debugEncoder {
println("Adding RAW block, length", len(a), "last:", b.last)
}
}
// encodeRaw can be used to set the output to a raw representation of supplied bytes.
func (b *blockEnc) encodeRawTo(dst, src []byte) []byte {
var bh blockHeader
bh.setLast(b.last)
bh.setSize(uint32(len(src)))
bh.setType(blockTypeRaw)
dst = bh.appendTo(dst)
dst = append(dst, src...)
if debugEncoder {
println("Adding RAW block, length", len(src), "last:", b.last)
}
return dst
}
// encodeLits can be used if the block is only litLen.
func (b *blockEnc) encodeLits(lits []byte, raw bool) error {
var bh blockHeader
bh.setLast(b.last)
bh.setSize(uint32(len(lits)))
// Don't compress extremely small blocks
if len(lits) < 8 || (len(lits) < 32 && b.dictLitEnc == nil) || raw {
if debugEncoder {
println("Adding RAW block, length", len(lits), "last:", b.last)
}
bh.setType(blockTypeRaw)
b.output = bh.appendTo(b.output)
b.output = append(b.output, lits...)
return nil
}
var (
out []byte
reUsed, single bool
err error
)
if b.dictLitEnc != nil {
b.litEnc.TransferCTable(b.dictLitEnc)
b.litEnc.Reuse = huff0.ReusePolicyAllow
b.dictLitEnc = nil
}
if len(lits) >= 1024 {
// Use 4 Streams.
out, reUsed, err = huff0.Compress4X(lits, b.litEnc)
} else if len(lits) > 16 {
// Use 1 stream
single = true
out, reUsed, err = huff0.Compress1X(lits, b.litEnc)
} else {
err = huff0.ErrIncompressible
}
if err == nil && len(out)+5 > len(lits) {
// If we are close, we may still be worse or equal to raw.
var lh literalsHeader
lh.setSizes(len(out), len(lits), single)
if len(out)+lh.size() >= len(lits) {
err = huff0.ErrIncompressible
}
}
switch err {
case huff0.ErrIncompressible:
if debugEncoder {
println("Adding RAW block, length", len(lits), "last:", b.last)
}
bh.setType(blockTypeRaw)
b.output = bh.appendTo(b.output)
b.output = append(b.output, lits...)
return nil
case huff0.ErrUseRLE:
if debugEncoder {
println("Adding RLE block, length", len(lits))
}
bh.setType(blockTypeRLE)
b.output = bh.appendTo(b.output)
b.output = append(b.output, lits[0])
return nil
case nil:
default:
return err
}
// Compressed...
// Now, allow reuse
b.litEnc.Reuse = huff0.ReusePolicyAllow
bh.setType(blockTypeCompressed)
var lh literalsHeader
if reUsed {
if debugEncoder {
println("Reused tree, compressed to", len(out))
}
lh.setType(literalsBlockTreeless)
} else {
if debugEncoder {
println("New tree, compressed to", len(out), "tree size:", len(b.litEnc.OutTable))
}
lh.setType(literalsBlockCompressed)
}
// Set sizes
lh.setSizes(len(out), len(lits), single)
bh.setSize(uint32(len(out) + lh.size() + 1))
// Write block headers.
b.output = bh.appendTo(b.output)
b.output = lh.appendTo(b.output)
// Add compressed data.
b.output = append(b.output, out...)
// No sequences.
b.output = append(b.output, 0)
return nil
}
// encodeRLE will encode an RLE block.
func (b *blockEnc) encodeRLE(val byte, length uint32) {
var bh blockHeader
bh.setLast(b.last)
bh.setSize(length)
bh.setType(blockTypeRLE)
b.output = bh.appendTo(b.output)
b.output = append(b.output, val)
}
// fuzzFseEncoder can be used to fuzz the FSE encoder.
func fuzzFseEncoder(data []byte) int {
if len(data) > maxSequences || len(data) < 2 {
return 0
}
enc := fseEncoder{}
hist := enc.Histogram()
maxSym := uint8(0)
for i, v := range data {
v = v & 63
data[i] = v
hist[v]++
if v > maxSym {
maxSym = v
}
}
if maxSym == 0 {
// All 0
return 0
}
cnt := int(slices.Max(hist[:maxSym]))
if cnt == len(data) {
// RLE
return 0
}
enc.HistogramFinished(maxSym, cnt)
err := enc.normalizeCount(len(data))
if err != nil {
return 0
}
_, err = enc.writeCount(nil)
if err != nil {
panic(err)
}
return 1
}
// encode will encode the block and append the output in b.output.
// Previous offset codes must be pushed if more blocks are expected.
func (b *blockEnc) encode(org []byte, raw, rawAllLits bool) error {
if len(b.sequences) == 0 {
return b.encodeLits(b.literals, rawAllLits)
}
if len(b.sequences) == 1 && len(org) > 0 && len(b.literals) <= 1 {
// Check common RLE cases.
seq := b.sequences[0]
if seq.litLen == uint32(len(b.literals)) && seq.offset-3 == 1 {
// Offset == 1 and 0 or 1 literals.
b.encodeRLE(org[0], b.sequences[0].matchLen+zstdMinMatch+seq.litLen)
return nil
}
}
// We want some difference to at least account for the headers.
saved := b.size - len(b.literals) - (b.size >> 6)
if saved < 16 {
if org == nil {
return errIncompressible
}
b.popOffsets()
return b.encodeLits(org, rawAllLits)
}
var bh blockHeader
var lh literalsHeader
bh.setLast(b.last)
bh.setType(blockTypeCompressed)
// Store offset of the block header. Needed when we know the size.
bhOffset := len(b.output)
b.output = bh.appendTo(b.output)
var (
out []byte
reUsed, single bool
err error
)
if b.dictLitEnc != nil {
b.litEnc.TransferCTable(b.dictLitEnc)
b.litEnc.Reuse = huff0.ReusePolicyAllow
b.dictLitEnc = nil
}
if len(b.literals) >= 1024 && !raw {
// Use 4 Streams.
out, reUsed, err = huff0.Compress4X(b.literals, b.litEnc)
} else if len(b.literals) > 16 && !raw {
// Use 1 stream
single = true
out, reUsed, err = huff0.Compress1X(b.literals, b.litEnc)
} else {
err = huff0.ErrIncompressible
}
if err == nil && len(out)+5 > len(b.literals) {
// If we are close, we may still be worse or equal to raw.
var lh literalsHeader
lh.setSize(len(b.literals))
szRaw := lh.size()
lh.setSizes(len(out), len(b.literals), single)
szComp := lh.size()
if len(out)+szComp >= len(b.literals)+szRaw {
err = huff0.ErrIncompressible
}
}
switch err {
case huff0.ErrIncompressible:
lh.setType(literalsBlockRaw)
lh.setSize(len(b.literals))
b.output = lh.appendTo(b.output)
b.output = append(b.output, b.literals...)
if debugEncoder {
println("Adding literals RAW, length", len(b.literals))
}
case huff0.ErrUseRLE:
lh.setType(literalsBlockRLE)
lh.setSize(len(b.literals))
b.output = lh.appendTo(b.output)
b.output = append(b.output, b.literals[0])
if debugEncoder {
println("Adding literals RLE")
}
case nil:
// Compressed litLen...
if reUsed {
if debugEncoder {
println("reused tree")
}
lh.setType(literalsBlockTreeless)
} else {
if debugEncoder {
println("new tree, size:", len(b.litEnc.OutTable))
}
lh.setType(literalsBlockCompressed)
if debugEncoder {
_, _, err := huff0.ReadTable(out, nil)
if err != nil {
panic(err)
}
}
}
lh.setSizes(len(out), len(b.literals), single)
if debugEncoder {
printf("Compressed %d literals to %d bytes", len(b.literals), len(out))
println("Adding literal header:", lh)
}
b.output = lh.appendTo(b.output)
b.output = append(b.output, out...)
b.litEnc.Reuse = huff0.ReusePolicyAllow
if debugEncoder {
println("Adding literals compressed")
}
default:
if debugEncoder {
println("Adding literals ERROR:", err)
}
return err
}
// Sequence compression
// Write the number of sequences
switch {
case len(b.sequences) < 128:
b.output = append(b.output, uint8(len(b.sequences)))
case len(b.sequences) < 0x7f00: // TODO: this could be wrong
n := len(b.sequences)
b.output = append(b.output, 128+uint8(n>>8), uint8(n))
default:
n := len(b.sequences) - 0x7f00
b.output = append(b.output, 255, uint8(n), uint8(n>>8))
}
if debugEncoder {
println("Encoding", len(b.sequences), "sequences")
}
b.genCodes()
llEnc := b.coders.llEnc
ofEnc := b.coders.ofEnc
mlEnc := b.coders.mlEnc
err = llEnc.normalizeCount(len(b.sequences))
if err != nil {
return err
}
err = ofEnc.normalizeCount(len(b.sequences))
if err != nil {
return err
}
err = mlEnc.normalizeCount(len(b.sequences))
if err != nil {
return err
}
// Choose the best compression mode for each type.
// Will evaluate the new vs predefined and previous.
chooseComp := func(cur, prev, preDef *fseEncoder) (*fseEncoder, seqCompMode) {
// See if predefined/previous is better
hist := cur.count[:cur.symbolLen]
nSize := cur.approxSize(hist) + cur.maxHeaderSize()
predefSize := preDef.approxSize(hist)
prevSize := prev.approxSize(hist)
// Add a small penalty for new encoders.
// Don't bother with extremely small (<2 byte gains).
nSize = nSize + (nSize+2*8*16)>>4
switch {
case predefSize <= prevSize && predefSize <= nSize || forcePreDef:
if debugEncoder {
println("Using predefined", predefSize>>3, "<=", nSize>>3)
}
return preDef, compModePredefined
case prevSize <= nSize:
if debugEncoder {
println("Using previous", prevSize>>3, "<=", nSize>>3)
}
return prev, compModeRepeat
default:
if debugEncoder {
println("Using new, predef", predefSize>>3, ". previous:", prevSize>>3, ">", nSize>>3, "header max:", cur.maxHeaderSize()>>3, "bytes")
println("tl:", cur.actualTableLog, "symbolLen:", cur.symbolLen, "norm:", cur.norm[:cur.symbolLen], "hist", cur.count[:cur.symbolLen])
}
return cur, compModeFSE
}
}
// Write compression mode
var mode uint8
if llEnc.useRLE {
mode |= uint8(compModeRLE) << 6
llEnc.setRLE(b.sequences[0].llCode)
if debugEncoder {
println("llEnc.useRLE")
}
} else {
var m seqCompMode
llEnc, m = chooseComp(llEnc, b.coders.llPrev, &fsePredefEnc[tableLiteralLengths])
mode |= uint8(m) << 6
}
if ofEnc.useRLE {
mode |= uint8(compModeRLE) << 4
ofEnc.setRLE(b.sequences[0].ofCode)
if debugEncoder {
println("ofEnc.useRLE")
}
} else {
var m seqCompMode
ofEnc, m = chooseComp(ofEnc, b.coders.ofPrev, &fsePredefEnc[tableOffsets])
mode |= uint8(m) << 4
}
if mlEnc.useRLE {
mode |= uint8(compModeRLE) << 2
mlEnc.setRLE(b.sequences[0].mlCode)
if debugEncoder {
println("mlEnc.useRLE, code: ", b.sequences[0].mlCode, "value", b.sequences[0].matchLen)
}
} else {
var m seqCompMode
mlEnc, m = chooseComp(mlEnc, b.coders.mlPrev, &fsePredefEnc[tableMatchLengths])
mode |= uint8(m) << 2
}
b.output = append(b.output, mode)
if debugEncoder {
printf("Compression modes: 0b%b", mode)
}
b.output, err = llEnc.writeCount(b.output)
if err != nil {
return err
}
start := len(b.output)
b.output, err = ofEnc.writeCount(b.output)
if err != nil {
return err
}
if false {
println("block:", b.output[start:], "tablelog", ofEnc.actualTableLog, "maxcount:", ofEnc.maxCount)
fmt.Printf("selected TableLog: %d, Symbol length: %d\n", ofEnc.actualTableLog, ofEnc.symbolLen)
for i, v := range ofEnc.norm[:ofEnc.symbolLen] {
fmt.Printf("%3d: %5d -> %4d \n", i, ofEnc.count[i], v)
}
}
b.output, err = mlEnc.writeCount(b.output)
if err != nil {
return err
}
// Maybe in block?
wr := &b.wr
wr.reset(b.output)
var ll, of, ml cState
// Current sequence
seq := len(b.sequences) - 1
s := b.sequences[seq]
llEnc.setBits(llBitsTable[:])
mlEnc.setBits(mlBitsTable[:])
ofEnc.setBits(nil)
llTT, ofTT, mlTT := llEnc.ct.symbolTT[:256], ofEnc.ct.symbolTT[:256], mlEnc.ct.symbolTT[:256]
// We have 3 bounds checks here (and in the loop).
// Since we are iterating backwards it is kinda hard to avoid.
llB, ofB, mlB := llTT[s.llCode], ofTT[s.ofCode], mlTT[s.mlCode]
ll.init(wr, &llEnc.ct, llB)
of.init(wr, &ofEnc.ct, ofB)
wr.flush32()
ml.init(wr, &mlEnc.ct, mlB)
// Each of these lookups also generates a bounds check.
wr.addBits32NC(s.litLen, llB.outBits)
wr.addBits32NC(s.matchLen, mlB.outBits)
wr.flush32()
wr.addBits32NC(s.offset, ofB.outBits)
if debugSequences {
println("Encoded seq", seq, s, "codes:", s.llCode, s.mlCode, s.ofCode, "states:", ll.state, ml.state, of.state, "bits:", llB, mlB, ofB)
}
seq--
// Store sequences in reverse...
for seq >= 0 {
s = b.sequences[seq]
ofB := ofTT[s.ofCode]
wr.flush32() // tablelog max is below 8 for each, so it will fill max 24 bits.
//of.encode(ofB)
nbBitsOut := (uint32(of.state) + ofB.deltaNbBits) >> 16
dstState := int32(of.state>>(nbBitsOut&15)) + int32(ofB.deltaFindState)
wr.addBits16NC(of.state, uint8(nbBitsOut))
of.state = of.stateTable[dstState]
// Accumulate extra bits.
outBits := ofB.outBits & 31
extraBits := uint64(s.offset & bitMask32[outBits])
extraBitsN := outBits
mlB := mlTT[s.mlCode]
//ml.encode(mlB)
nbBitsOut = (uint32(ml.state) + mlB.deltaNbBits) >> 16
dstState = int32(ml.state>>(nbBitsOut&15)) + int32(mlB.deltaFindState)
wr.addBits16NC(ml.state, uint8(nbBitsOut))
ml.state = ml.stateTable[dstState]
outBits = mlB.outBits & 31
extraBits = extraBits<<outBits | uint64(s.matchLen&bitMask32[outBits])
extraBitsN += outBits
llB := llTT[s.llCode]
//ll.encode(llB)
nbBitsOut = (uint32(ll.state) + llB.deltaNbBits) >> 16
dstState = int32(ll.state>>(nbBitsOut&15)) + int32(llB.deltaFindState)
wr.addBits16NC(ll.state, uint8(nbBitsOut))
ll.state = ll.stateTable[dstState]
outBits = llB.outBits & 31
extraBits = extraBits<<outBits | uint64(s.litLen&bitMask32[outBits])
extraBitsN += outBits
wr.flush32()
wr.addBits64NC(extraBits, extraBitsN)
if debugSequences {
println("Encoded seq", seq, s)
}
seq--
}
ml.flush(mlEnc.actualTableLog)
of.flush(ofEnc.actualTableLog)
ll.flush(llEnc.actualTableLog)
wr.close()
b.output = wr.out
// Maybe even add a bigger margin.
if len(b.output)-3-bhOffset >= b.size {
// Discard and encode as raw block.
b.output = b.encodeRawTo(b.output[:bhOffset], org)
b.popOffsets()
b.litEnc.Reuse = huff0.ReusePolicyNone
return nil
}
// Size is output minus block header.
bh.setSize(uint32(len(b.output)-bhOffset) - 3)
if debugEncoder {
println("Rewriting block header", bh)
}
_ = bh.appendTo(b.output[bhOffset:bhOffset])
b.coders.setPrev(llEnc, mlEnc, ofEnc)
return nil
}
var errIncompressible = errors.New("incompressible")
func (b *blockEnc) genCodes() {
if len(b.sequences) == 0 {
// nothing to do
return
}
if len(b.sequences) > math.MaxUint16 {
panic("can only encode up to 64K sequences")
}
// No bounds checks after here:
llH := b.coders.llEnc.Histogram()
ofH := b.coders.ofEnc.Histogram()
mlH := b.coders.mlEnc.Histogram()
for i := range llH {
llH[i] = 0
}
for i := range ofH {
ofH[i] = 0
}
for i := range mlH {
mlH[i] = 0
}
var llMax, ofMax, mlMax uint8
for i := range b.sequences {
seq := &b.sequences[i]
v := llCode(seq.litLen)
seq.llCode = v
llH[v]++
if v > llMax {
llMax = v
}
v = ofCode(seq.offset)
seq.ofCode = v
ofH[v]++
if v > ofMax {
ofMax = v
}
v = mlCode(seq.matchLen)
seq.mlCode = v
mlH[v]++
if v > mlMax {
mlMax = v
if debugAsserts && mlMax > maxMatchLengthSymbol {
panic(fmt.Errorf("mlMax > maxMatchLengthSymbol (%d), matchlen: %d", mlMax, seq.matchLen))
}
}
}
if debugAsserts && mlMax > maxMatchLengthSymbol {
panic(fmt.Errorf("mlMax > maxMatchLengthSymbol (%d)", mlMax))
}
if debugAsserts && ofMax > maxOffsetBits {
panic(fmt.Errorf("ofMax > maxOffsetBits (%d)", ofMax))
}
if debugAsserts && llMax > maxLiteralLengthSymbol {
panic(fmt.Errorf("llMax > maxLiteralLengthSymbol (%d)", llMax))
}
b.coders.mlEnc.HistogramFinished(mlMax, int(slices.Max(mlH[:mlMax+1])))
b.coders.ofEnc.HistogramFinished(ofMax, int(slices.Max(ofH[:ofMax+1])))
b.coders.llEnc.HistogramFinished(llMax, int(slices.Max(llH[:llMax+1])))
}
Server/vendor/github.com/klauspost/compress/zstd/blocktype_string.go
Generated Vendored
+85
View File
@@ -0,0 +1,85 @@
// Code generated by "stringer -type=blockType,literalsBlockType,seqCompMode,tableIndex"; DO NOT EDIT.
package zstd
import "strconv"
func _() {
// An "invalid array index" compiler error signifies that the constant values have changed.
// Re-run the stringer command to generate them again.
var x [1]struct{}
_ = x[blockTypeRaw-0]
_ = x[blockTypeRLE-1]
_ = x[blockTypeCompressed-2]
_ = x[blockTypeReserved-3]
}
const _blockType_name = "blockTypeRawblockTypeRLEblockTypeCompressedblockTypeReserved"
var _blockType_index = [...]uint8{0, 12, 24, 43, 60}
func (i blockType) String() string {
if i >= blockType(len(_blockType_index)-1) {
return "blockType(" + strconv.FormatInt(int64(i), 10) + ")"
}
return _blockType_name[_blockType_index[i]:_blockType_index[i+1]]
}
func _() {
// An "invalid array index" compiler error signifies that the constant values have changed.
// Re-run the stringer command to generate them again.
var x [1]struct{}
_ = x[literalsBlockRaw-0]
_ = x[literalsBlockRLE-1]
_ = x[literalsBlockCompressed-2]
_ = x[literalsBlockTreeless-3]
}
const _literalsBlockType_name = "literalsBlockRawliteralsBlockRLEliteralsBlockCompressedliteralsBlockTreeless"
var _literalsBlockType_index = [...]uint8{0, 16, 32, 55, 76}
func (i literalsBlockType) String() string {
if i >= literalsBlockType(len(_literalsBlockType_index)-1) {
return "literalsBlockType(" + strconv.FormatInt(int64(i), 10) + ")"
}
return _literalsBlockType_name[_literalsBlockType_index[i]:_literalsBlockType_index[i+1]]
}
func _() {
// An "invalid array index" compiler error signifies that the constant values have changed.
// Re-run the stringer command to generate them again.
var x [1]struct{}
_ = x[compModePredefined-0]
_ = x[compModeRLE-1]
_ = x[compModeFSE-2]
_ = x[compModeRepeat-3]
}
const _seqCompMode_name = "compModePredefinedcompModeRLEcompModeFSEcompModeRepeat"
var _seqCompMode_index = [...]uint8{0, 18, 29, 40, 54}
func (i seqCompMode) String() string {
if i >= seqCompMode(len(_seqCompMode_index)-1) {
return "seqCompMode(" + strconv.FormatInt(int64(i), 10) + ")"
}
return _seqCompMode_name[_seqCompMode_index[i]:_seqCompMode_index[i+1]]
}
func _() {
// An "invalid array index" compiler error signifies that the constant values have changed.
// Re-run the stringer command to generate them again.
var x [1]struct{}
_ = x[tableLiteralLengths-0]
_ = x[tableOffsets-1]
_ = x[tableMatchLengths-2]
}
const _tableIndex_name = "tableLiteralLengthstableOffsetstableMatchLengths"
var _tableIndex_index = [...]uint8{0, 19, 31, 48}
func (i tableIndex) String() string {
if i >= tableIndex(len(_tableIndex_index)-1) {
return "tableIndex(" + strconv.FormatInt(int64(i), 10) + ")"
}
return _tableIndex_name[_tableIndex_index[i]:_tableIndex_index[i+1]]
}

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