Курнат Андрей
74 lines
1.1 KiB
Go
74 lines
1.1 KiB
Go
package topdown
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import (
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"bytes"
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"io"
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)
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var _ io.Writer = (*sinkW)(nil)
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type sinkWriter interface {
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io.Writer
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String() string
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Grow(int)
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WriteByte(byte) error
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WriteString(string) (int, error)
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}
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type sinkW struct {
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buf *bytes.Buffer
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cancel Cancel
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err error
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}
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func newSink(name string, hint int, c Cancel) sinkWriter {
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b := &bytes.Buffer{}
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if hint > 0 {
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b.Grow(hint)
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}
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if c == nil {
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return b
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}
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return &sinkW{
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cancel: c,
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buf: b,
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err: Halt{
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Err: &Error{
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Code: CancelErr,
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Message: name + ": timed out before finishing",
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},
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},
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}
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}
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func (sw *sinkW) Grow(n int) {
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sw.buf.Grow(n)
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}
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func (sw *sinkW) Write(bs []byte) (int, error) {
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if sw.cancel.Cancelled() {
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return 0, sw.err
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}
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return sw.buf.Write(bs)
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}
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func (sw *sinkW) WriteByte(b byte) error {
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if sw.cancel.Cancelled() {
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return sw.err
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}
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return sw.buf.WriteByte(b)
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}
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func (sw *sinkW) WriteString(s string) (int, error) {
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if sw.cancel.Cancelled() {
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return 0, sw.err
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}
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return sw.buf.WriteString(s)
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}
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func (sw *sinkW) String() string {
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return sw.buf.String()
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}
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