Initial QSfera import

Server/vendor/github.com/KimMachineGun/automemlimit/memlimit/cgroups.go

@@ -0,0 +1,441 @@
+package memlimit
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"math"
+	"os"
+	"path/filepath"
+	"slices"
+	"strconv"
+	"strings"
+)
+
+var (
+	// ErrNoCgroup is returned when the process is not in cgroup.
+	ErrNoCgroup = errors.New("process is not in cgroup")
+	// ErrCgroupsNotSupported is returned when the system does not support cgroups.
+	ErrCgroupsNotSupported = errors.New("cgroups is not supported on this system")
+)
+
+// fromCgroup retrieves the memory limit from the cgroup.
+// The versionDetector function is used to detect the cgroup version from the mountinfo.
+func fromCgroup(versionDetector func(mis []mountInfo) (bool, bool)) (uint64, error) {
+	mf, err := os.Open("/proc/self/mountinfo")
+	if err != nil {
+		return 0, fmt.Errorf("failed to open /proc/self/mountinfo: %w", err)
+	}
+	defer mf.Close()
+
+	mis, err := parseMountInfo(mf)
+	if err != nil {
+		return 0, fmt.Errorf("failed to parse mountinfo: %w", err)
+	}
+
+	v1, v2 := versionDetector(mis)
+	if !(v1 || v2) {
+		return 0, ErrNoCgroup
+	}
+
+	cf, err := os.Open("/proc/self/cgroup")
+	if err != nil {
+		return 0, fmt.Errorf("failed to open /proc/self/cgroup: %w", err)
+	}
+	defer cf.Close()
+
+	chs, err := parseCgroupFile(cf)
+	if err != nil {
+		return 0, fmt.Errorf("failed to parse cgroup file: %w", err)
+	}
+
+	if v2 {
+		limit, err := getMemoryLimitV2(chs, mis)
+		if err == nil {
+			return limit, nil
+		} else if !v1 {
+			return 0, err
+		}
+	}
+
+	return getMemoryLimitV1(chs, mis)
+}
+
+// detectCgroupVersion detects the cgroup version from the mountinfo.
+func detectCgroupVersion(mis []mountInfo) (bool, bool) {
+	var v1, v2 bool
+	for _, mi := range mis {
+		switch mi.FilesystemType {
+		case "cgroup":
+			v1 = true
+		case "cgroup2":
+			v2 = true
+		}
+	}
+	return v1, v2
+}
+
+// getMemoryLimitV2 retrieves the memory limit from the cgroup v2 controller.
+func getMemoryLimitV2(chs []cgroupHierarchy, mis []mountInfo) (uint64, error) {
+	// find the cgroup v2 path for the memory controller.
+	// in cgroup v2, the paths are unified and the controller list is empty.
+	idx := slices.IndexFunc(chs, func(ch cgroupHierarchy) bool {
+		return ch.HierarchyID == "0" && ch.ControllerList == ""
+	})
+	if idx == -1 {
+		return 0, errors.New("cgroup v2 path not found")
+	}
+	relPath := chs[idx].CgroupPath
+
+	// find the mountpoint for the cgroup v2 controller.
+	idx = slices.IndexFunc(mis, func(mi mountInfo) bool {
+		return mi.FilesystemType == "cgroup2"
+	})
+	if idx == -1 {
+		return 0, errors.New("cgroup v2 mountpoint not found")
+	}
+	root, mountPoint := mis[idx].Root, mis[idx].MountPoint
+
+	// resolve the actual cgroup path
+	cgroupPath, err := resolveCgroupPath(mountPoint, root, relPath)
+	if err != nil {
+		return 0, err
+	}
+
+	// retrieve the memory limit from the memory.max recursively.
+	return walkCgroupV2Hierarchy(cgroupPath, mountPoint)
+}
+
+// readMemoryLimitV2FromPath reads the memory limit for cgroup v2 from the given path.
+// this function expects the path to be memory.max file.
+func readMemoryLimitV2FromPath(path string) (uint64, error) {
+	b, err := os.ReadFile(path)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return 0, ErrNoLimit
+		}
+		return 0, fmt.Errorf("failed to read memory.max: %w", err)
+	}
+
+	slimit := strings.TrimSpace(string(b))
+	if slimit == "max" {
+		return 0, ErrNoLimit
+	}
+
+	limit, err := strconv.ParseUint(slimit, 10, 64)
+	if err != nil {
+		return 0, fmt.Errorf("failed to parse memory.max value: %w", err)
+	}
+
+	return limit, nil
+}
+
+// walkCgroupV2Hierarchy walks up the cgroup v2 hierarchy to find the most restrictive memory limit.
+func walkCgroupV2Hierarchy(cgroupPath, mountPoint string) (uint64, error) {
+	var (
+		found              = false
+		minLimit    uint64 = math.MaxUint64
+		currentPath        = cgroupPath
+	)
+	for {
+		limit, err := readMemoryLimitV2FromPath(filepath.Join(currentPath, "memory.max"))
+		if err != nil && !errors.Is(err, ErrNoLimit) {
+			return 0, err
+		} else if err == nil {
+			found = true
+			minLimit = min(minLimit, limit)
+		}
+
+		if currentPath == mountPoint {
+			break
+		}
+
+		parent := filepath.Dir(currentPath)
+		if parent == currentPath {
+			break
+		}
+		currentPath = parent
+	}
+	if !found {
+		return 0, ErrNoLimit
+	}
+
+	return minLimit, nil
+}
+
+// getMemoryLimitV1 retrieves the memory limit from the cgroup v1 controller.
+func getMemoryLimitV1(chs []cgroupHierarchy, mis []mountInfo) (uint64, error) {
+	// find the cgroup v1 path for the memory controller.
+	idx := slices.IndexFunc(chs, func(ch cgroupHierarchy) bool {
+		return slices.Contains(strings.Split(ch.ControllerList, ","), "memory")
+	})
+	if idx == -1 {
+		return 0, errors.New("cgroup v1 path for memory controller not found")
+	}
+	relPath := chs[idx].CgroupPath
+
+	// find the mountpoint for the cgroup v1 controller.
+	idx = slices.IndexFunc(mis, func(mi mountInfo) bool {
+		return mi.FilesystemType == "cgroup" && slices.Contains(strings.Split(mi.SuperOptions, ","), "memory")
+	})
+	if idx == -1 {
+		return 0, errors.New("cgroup v1 mountpoint for memory controller not found")
+	}
+	root, mountPoint := mis[idx].Root, mis[idx].MountPoint
+
+	// resolve the actual cgroup path
+	cgroupPath, err := resolveCgroupPath(mountPoint, root, relPath)
+	if err != nil {
+		return 0, err
+	}
+
+	// retrieve the memory limit from the memory.stat and memory.limit_in_bytes files.
+	return readMemoryLimitV1FromPath(cgroupPath)
+}
+
+// getCgroupV1NoLimit returns the maximum value that is used to represent no limit in cgroup v1.
+// the max memory limit is max int64, but it should be multiple of the page size.
+func getCgroupV1NoLimit() uint64 {
+	ps := uint64(os.Getpagesize())
+	return math.MaxInt64 / ps * ps
+}
+
+// readMemoryLimitV1FromPath reads the memory limit for cgroup v1 from the given path.
+// this function expects the path to be the cgroup directory.
+func readMemoryLimitV1FromPath(cgroupPath string) (uint64, error) {
+	// read hierarchical_memory_limit and memory.limit_in_bytes files.
+	// but if hierarchical_memory_limit is not available, then use the max value as a fallback.
+	hml, err := readHierarchicalMemoryLimit(filepath.Join(cgroupPath, "memory.stat"))
+	if err != nil && !errors.Is(err, os.ErrNotExist) {
+		return 0, fmt.Errorf("failed to read hierarchical_memory_limit: %w", err)
+	} else if hml == 0 {
+		hml = math.MaxUint64
+	}
+
+	// read memory.limit_in_bytes file.
+	b, err := os.ReadFile(filepath.Join(cgroupPath, "memory.limit_in_bytes"))
+	if err != nil && !errors.Is(err, os.ErrNotExist) {
+		return 0, fmt.Errorf("failed to read memory.limit_in_bytes: %w", err)
+	}
+	lib, err := strconv.ParseUint(strings.TrimSpace(string(b)), 10, 64)
+	if err != nil {
+		return 0, fmt.Errorf("failed to parse memory.limit_in_bytes value: %w", err)
+	} else if lib == 0 {
+		hml = math.MaxUint64
+	}
+
+	// use the minimum value between hierarchical_memory_limit and memory.limit_in_bytes.
+	// if the limit is the maximum value, then it is considered as no limit.
+	limit := min(hml, lib)
+	if limit >= getCgroupV1NoLimit() {
+		return 0, ErrNoLimit
+	}
+
+	return limit, nil
+}
+
+// readHierarchicalMemoryLimit extracts hierarchical_memory_limit from memory.stat.
+// this function expects the path to be memory.stat file.
+func readHierarchicalMemoryLimit(path string) (uint64, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return 0, err
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := scanner.Text()
+
+		fields := strings.Split(line, " ")
+		if len(fields) < 2 {
+			return 0, fmt.Errorf("failed to parse memory.stat %q: not enough fields", line)
+		}
+
+		if fields[0] == "hierarchical_memory_limit" {
+			if len(fields) > 2 {
+				return 0, fmt.Errorf("failed to parse memory.stat %q: too many fields for hierarchical_memory_limit", line)
+			}
+			return strconv.ParseUint(fields[1], 10, 64)
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		return 0, err
+	}
+
+	return 0, nil
+}
+
+// https://www.man7.org/linux/man-pages/man5/proc_pid_mountinfo.5.html
+// 731 771 0:59 /sysrq-trigger /proc/sysrq-trigger ro,nosuid,nodev,noexec,relatime - proc proc rw
+//
+// 36 35 98:0 /mnt1 /mnt2 rw,noatime master:1 - ext3 /dev/root rw,errors=continue
+// (1)(2)(3)   (4)   (5)      (6)      (7)   (8) (9)   (10)         (11)
+//
+// (1)  mount ID: a unique ID for the mount (may be reused after umount(2)).
+// (2)  parent ID: the ID of the parent mount (or of self for the root of this mount namespace's mount tree).
+// (3)  major:minor: the value of st_dev for files on this filesystem (see stat(2)).
+// (4)  root: the pathname of the directory in the filesystem which forms the root of this mount.
+// (5)  mount point: the pathname of the mount point relative to the process's root directory.
+// (6)  mount options: per-mount options (see mount(2)).
+// (7)  optional fields: zero or more fields of the form "tag[:value]"; see below.
+// (8)  separator: the end of the optional fields is marked by a single hyphen.
+// (9)  filesystem type: the filesystem type in the form "type[.subtype]".
+// (10) mount source: filesystem-specific information or "none".
+// (11) super options: per-superblock options (see mount(2)).
+type mountInfo struct {
+	Root           string
+	MountPoint     string
+	FilesystemType string
+	SuperOptions   string
+}
+
+// parseMountInfoLine parses a line from the mountinfo file.
+func parseMountInfoLine(line string) (mountInfo, error) {
+	if line == "" {
+		return mountInfo{}, errors.New("empty line")
+	}
+
+	fieldss := strings.SplitN(line, " - ", 2)
+	if len(fieldss) != 2 {
+		return mountInfo{}, fmt.Errorf("invalid separator")
+	}
+
+	fields1 := strings.SplitN(fieldss[0], " ", 7)
+	if len(fields1) < 6 {
+		return mountInfo{}, fmt.Errorf("not enough fields before separator: %v", fields1)
+	} else if len(fields1) == 6 {
+		fields1 = append(fields1, "")
+	}
+
+	fields2 := strings.SplitN(fieldss[1], " ", 3)
+	if len(fields2) < 3 {
+		return mountInfo{}, fmt.Errorf("not enough fields after separator: %v", fields2)
+	}
+
+	return mountInfo{
+		Root:           fields1[3],
+		MountPoint:     fields1[4],
+		FilesystemType: fields2[0],
+		SuperOptions:   fields2[2],
+	}, nil
+}
+
+// parseMountInfo parses the mountinfo file.
+func parseMountInfo(r io.Reader) ([]mountInfo, error) {
+	var (
+		s   = bufio.NewScanner(r)
+		mis []mountInfo
+	)
+	for s.Scan() {
+		line := s.Text()
+
+		mi, err := parseMountInfoLine(line)
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse mountinfo file %q: %w", line, err)
+		}
+
+		mis = append(mis, mi)
+	}
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+
+	return mis, nil
+}
+
+// https://www.man7.org/linux/man-pages/man7/cgroups.7.html
+//
+// 5:cpuacct,cpu,cpuset:/daemons
+// (1)       (2)           (3)
+//
+// (1) hierarchy ID:
+//
+//	cgroups version 1 hierarchies, this field
+//	contains a unique hierarchy ID number that can be
+//	matched to a hierarchy ID in /proc/cgroups.  For the
+//	cgroups version 2 hierarchy, this field contains the
+//	value 0.
+//
+// (2) controller list:
+//
+//	For cgroups version 1 hierarchies, this field
+//	contains a comma-separated list of the controllers
+//	bound to the hierarchy.  For the cgroups version 2
+//	hierarchy, this field is empty.
+//
+// (3) cgroup path:
+//
+//	This field contains the pathname of the control group
+//	in the hierarchy to which the process belongs.  This
+//	pathname is relative to the mount point of the
+//	hierarchy.
+type cgroupHierarchy struct {
+	HierarchyID    string
+	ControllerList string
+	CgroupPath     string
+}
+
+// parseCgroupHierarchyLine parses a line from the cgroup file.
+func parseCgroupHierarchyLine(line string) (cgroupHierarchy, error) {
+	if line == "" {
+		return cgroupHierarchy{}, errors.New("empty line")
+	}
+
+	fields := strings.Split(line, ":")
+	if len(fields) < 3 {
+		return cgroupHierarchy{}, fmt.Errorf("not enough fields: %v", fields)
+	} else if len(fields) > 3 {
+		return cgroupHierarchy{}, fmt.Errorf("too many fields: %v", fields)
+	}
+
+	return cgroupHierarchy{
+		HierarchyID:    fields[0],
+		ControllerList: fields[1],
+		CgroupPath:     fields[2],
+	}, nil
+}
+
+// parseCgroupFile parses the cgroup file.
+func parseCgroupFile(r io.Reader) ([]cgroupHierarchy, error) {
+	var (
+		s   = bufio.NewScanner(r)
+		chs []cgroupHierarchy
+	)
+	for s.Scan() {
+		line := s.Text()
+
+		ch, err := parseCgroupHierarchyLine(line)
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse cgroup file %q: %w", line, err)
+		}
+
+		chs = append(chs, ch)
+	}
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+
+	return chs, nil
+}
+
+// resolveCgroupPath resolves the actual cgroup path from the mountpoint, root, and cgroupRelPath.
+func resolveCgroupPath(mountpoint, root, cgroupRelPath string) (string, error) {
+	rel, err := filepath.Rel(root, cgroupRelPath)
+	if err != nil {
+		return "", err
+	}
+
+	// if the relative path is ".", then the cgroupRelPath is the root itself.
+	if rel == "." {
+		return mountpoint, nil
+	}
+
+	// if the relative path starts with "..", then it is outside the root.
+	if strings.HasPrefix(rel, "..") {
+		return "", fmt.Errorf("invalid cgroup path: %s is not under root %s", cgroupRelPath, root)
+	}
+
+	return filepath.Join(mountpoint, rel), nil
+}

Server/vendor/github.com/KimMachineGun/automemlimit/memlimit/cgroups_linux.go

@@ -0,0 +1,32 @@
+//go:build linux
+// +build linux
+
+package memlimit
+
+// FromCgroup retrieves the memory limit from the cgroup.
+func FromCgroup() (uint64, error) {
+	return fromCgroup(detectCgroupVersion)
+}
+
+// FromCgroupV1 retrieves the memory limit from the cgroup v1 controller.
+// After v1.0.0, this function could be removed and FromCgroup should be used instead.
+func FromCgroupV1() (uint64, error) {
+	return fromCgroup(func(_ []mountInfo) (bool, bool) {
+		return true, false
+	})
+}
+
+// FromCgroupHybrid retrieves the memory limit from the cgroup v2 and v1 controller sequentially,
+// basically, it is equivalent to FromCgroup.
+// After v1.0.0, this function could be removed and FromCgroup should be used instead.
+func FromCgroupHybrid() (uint64, error) {
+	return FromCgroup()
+}
+
+// FromCgroupV2 retrieves the memory limit from the cgroup v2 controller.
+// After v1.0.0, this function could be removed and FromCgroup should be used instead.
+func FromCgroupV2() (uint64, error) {
+	return fromCgroup(func(_ []mountInfo) (bool, bool) {
+		return false, true
+	})
+}

Server/vendor/github.com/KimMachineGun/automemlimit/memlimit/cgroups_unsupported.go

@@ -0,0 +1,20 @@
+//go:build !linux
+// +build !linux
+
+package memlimit
+
+func FromCgroup() (uint64, error) {
+	return 0, ErrCgroupsNotSupported
+}
+
+func FromCgroupV1() (uint64, error) {
+	return 0, ErrCgroupsNotSupported
+}
+
+func FromCgroupHybrid() (uint64, error) {
+	return 0, ErrCgroupsNotSupported
+}
+
+func FromCgroupV2() (uint64, error) {
+	return 0, ErrCgroupsNotSupported
+}

Server/vendor/github.com/KimMachineGun/automemlimit/memlimit/exp_system.go

@@ -0,0 +1,14 @@
+package memlimit
+
+import (
+	"github.com/pbnjay/memory"
+)
+
+// FromSystem returns the total memory of the system.
+func FromSystem() (uint64, error) {
+	limit := memory.TotalMemory()
+	if limit == 0 {
+		return 0, ErrNoLimit
+	}
+	return limit, nil
+}

Server/vendor/github.com/KimMachineGun/automemlimit/memlimit/experiment.go

@@ -0,0 +1,59 @@
+package memlimit
+
+import (
+	"fmt"
+	"os"
+	"reflect"
+	"strings"
+)
+
+const (
+	envAUTOMEMLIMIT_EXPERIMENT = "AUTOMEMLIMIT_EXPERIMENT"
+)
+
+// Experiments is a set of experiment flags.
+// It is used to enable experimental features.
+//
+// You can set the flags by setting the environment variable AUTOMEMLIMIT_EXPERIMENT.
+// The value of the environment variable is a comma-separated list of experiment names.
+//
+// The following experiment names are known:
+//
+//   - none: disable all experiments
+//   - system: enable fallback to system memory limit
+type Experiments struct {
+	// System enables fallback to system memory limit.
+	System bool
+}
+
+func parseExperiments() (Experiments, error) {
+	var exp Experiments
+
+	// Create a map of known experiment names.
+	names := make(map[string]func(bool))
+	rv := reflect.ValueOf(&exp).Elem()
+	rt := rv.Type()
+	for i := 0; i < rt.NumField(); i++ {
+		field := rv.Field(i)
+		names[strings.ToLower(rt.Field(i).Name)] = field.SetBool
+	}
+
+	// Parse names.
+	for _, f := range strings.Split(os.Getenv(envAUTOMEMLIMIT_EXPERIMENT), ",") {
+		if f == "" {
+			continue
+		}
+		if f == "none" {
+			exp = Experiments{}
+			continue
+		}
+		val := true
+		set, ok := names[f]
+		if !ok {
+			return Experiments{}, fmt.Errorf("unknown AUTOMEMLIMIT_EXPERIMENT %s", f)
+		}
+		set(val)
+	}
+
+	return exp, nil
+}

Server/vendor/github.com/KimMachineGun/automemlimit/memlimit/logger.go

@@ -0,0 +1,13 @@
+package memlimit
+
+import (
+	"context"
+	"log/slog"
+)
+
+type noopLogger struct{}
+
+func (noopLogger) Enabled(context.Context, slog.Level) bool  { return false }
+func (noopLogger) Handle(context.Context, slog.Record) error { return nil }
+func (d noopLogger) WithAttrs([]slog.Attr) slog.Handler      { return d }
+func (d noopLogger) WithGroup(string) slog.Handler           { return d }

Server/vendor/github.com/KimMachineGun/automemlimit/memlimit/memlimit.go

@@ -0,0 +1,285 @@
+package memlimit
+
+import (
+	"errors"
+	"fmt"
+	"log/slog"
+	"math"
+	"os"
+	"runtime/debug"
+	"strconv"
+	"time"
+)
+
+const (
+	envGOMEMLIMIT   = "GOMEMLIMIT"
+	envAUTOMEMLIMIT = "AUTOMEMLIMIT"
+	// Deprecated: use memlimit.WithLogger instead
+	envAUTOMEMLIMIT_DEBUG = "AUTOMEMLIMIT_DEBUG"
+
+	defaultAUTOMEMLIMIT = 0.9
+)
+
+// ErrNoLimit is returned when the memory limit is not set.
+var ErrNoLimit = errors.New("memory is not limited")
+
+type config struct {
+	logger   *slog.Logger
+	ratio    float64
+	provider Provider
+	refresh  time.Duration
+}
+
+// Option is a function that configures the behavior of SetGoMemLimitWithOptions.
+type Option func(cfg *config)
+
+// WithRatio configures the ratio of the memory limit to set as GOMEMLIMIT.
+//
+// Default: 0.9
+func WithRatio(ratio float64) Option {
+	return func(cfg *config) {
+		cfg.ratio = ratio
+	}
+}
+
+// WithProvider configures the provider.
+//
+// Default: FromCgroup
+func WithProvider(provider Provider) Option {
+	return func(cfg *config) {
+		cfg.provider = provider
+	}
+}
+
+// WithLogger configures the logger.
+// It automatically attaches the "package" attribute to the logs.
+//
+// Default: slog.New(noopLogger{})
+func WithLogger(logger *slog.Logger) Option {
+	return func(cfg *config) {
+		cfg.logger = memlimitLogger(logger)
+	}
+}
+
+// WithRefreshInterval configures the refresh interval for automemlimit.
+// If a refresh interval is greater than 0, automemlimit periodically fetches
+// the memory limit from the provider and reapplies it if it has changed.
+// If the provider returns an error, it logs the error and continues.
+// ErrNoLimit is treated as math.MaxInt64.
+//
+// Default: 0 (no refresh)
+func WithRefreshInterval(refresh time.Duration) Option {
+	return func(cfg *config) {
+		cfg.refresh = refresh
+	}
+}
+
+// WithEnv configures whether to use environment variables.
+//
+// Default: false
+//
+// Deprecated: currently this does nothing.
+func WithEnv() Option {
+	return func(cfg *config) {}
+}
+
+func memlimitLogger(logger *slog.Logger) *slog.Logger {
+	if logger == nil {
+		return slog.New(noopLogger{})
+	}
+	return logger.With(slog.String("package", "github.com/KimMachineGun/automemlimit/memlimit"))
+}
+
+// SetGoMemLimitWithOpts sets GOMEMLIMIT with options and environment variables.
+//
+// You can configure how much memory of the cgroup's memory limit to set as GOMEMLIMIT
+// through AUTOMEMLIMIT environment variable in the half-open range (0.0,1.0].
+//
+// If AUTOMEMLIMIT is not set, it defaults to 0.9. (10% is the headroom for memory sources the Go runtime is unaware of.)
+// If GOMEMLIMIT is already set or AUTOMEMLIMIT=off, this function does nothing.
+//
+// If AUTOMEMLIMIT_EXPERIMENT is set, it enables experimental features.
+// Please see the documentation of Experiments for more details.
+//
+// Options:
+//   - WithRatio
+//   - WithProvider
+//   - WithLogger
+func SetGoMemLimitWithOpts(opts ...Option) (_ int64, _err error) {
+	// init config
+	cfg := &config{
+		logger:   slog.New(noopLogger{}),
+		ratio:    defaultAUTOMEMLIMIT,
+		provider: FromCgroup,
+	}
+	// TODO: remove this
+	if debug, ok := os.LookupEnv(envAUTOMEMLIMIT_DEBUG); ok {
+		defaultLogger := memlimitLogger(slog.Default())
+		defaultLogger.Warn("AUTOMEMLIMIT_DEBUG is deprecated, use memlimit.WithLogger instead")
+		if debug == "true" {
+			cfg.logger = defaultLogger
+		}
+	}
+	for _, opt := range opts {
+		opt(cfg)
+	}
+
+	// log error if any on return
+	defer func() {
+		if _err != nil {
+			cfg.logger.Error("failed to set GOMEMLIMIT", slog.Any("error", _err))
+		}
+	}()
+
+	// parse experiments
+	exps, err := parseExperiments()
+	if err != nil {
+		return 0, fmt.Errorf("failed to parse experiments: %w", err)
+	}
+	if exps.System {
+		cfg.logger.Info("system experiment is enabled: using system memory limit as a fallback")
+		cfg.provider = ApplyFallback(cfg.provider, FromSystem)
+	}
+
+	// rollback to previous memory limit on panic
+	snapshot := debug.SetMemoryLimit(-1)
+	defer rollbackOnPanic(cfg.logger, snapshot, &_err)
+
+	// check if GOMEMLIMIT is already set
+	if val, ok := os.LookupEnv(envGOMEMLIMIT); ok {
+		cfg.logger.Info("GOMEMLIMIT is already set, skipping", slog.String(envGOMEMLIMIT, val))
+		return 0, nil
+	}
+
+	// parse AUTOMEMLIMIT
+	ratio := cfg.ratio
+	if val, ok := os.LookupEnv(envAUTOMEMLIMIT); ok {
+		if val == "off" {
+			cfg.logger.Info("AUTOMEMLIMIT is set to off, skipping")
+			return 0, nil
+		}
+		ratio, err = strconv.ParseFloat(val, 64)
+		if err != nil {
+			return 0, fmt.Errorf("cannot parse AUTOMEMLIMIT: %s", val)
+		}
+	}
+
+	// apply ratio to the provider
+	provider := capProvider(ApplyRatio(cfg.provider, ratio))
+
+	// set the memory limit and start refresh
+	limit, err := updateGoMemLimit(uint64(snapshot), provider, cfg.logger)
+	refresh(provider, cfg.logger, cfg.refresh)
+	if err != nil {
+		if errors.Is(err, ErrNoLimit) {
+			cfg.logger.Info("memory is not limited, skipping")
+			// TODO: consider returning the snapshot
+			return 0, nil
+		}
+		return 0, fmt.Errorf("failed to set GOMEMLIMIT: %w", err)
+	}
+
+	return int64(limit), nil
+}
+
+// updateGoMemLimit updates the Go's memory limit, if it has changed.
+func updateGoMemLimit(currLimit uint64, provider Provider, logger *slog.Logger) (uint64, error) {
+	newLimit, err := provider()
+	if err != nil {
+		return 0, err
+	}
+
+	if newLimit == currLimit {
+		logger.Debug("GOMEMLIMIT is not changed, skipping", slog.Uint64(envGOMEMLIMIT, newLimit))
+		return newLimit, nil
+	}
+
+	debug.SetMemoryLimit(int64(newLimit))
+	logger.Info("GOMEMLIMIT is updated", slog.Uint64(envGOMEMLIMIT, newLimit), slog.Uint64("previous", currLimit))
+
+	return newLimit, nil
+}
+
+// refresh spawns a goroutine that runs every refresh duration and updates the GOMEMLIMIT if it has changed.
+// See more details in the documentation of WithRefreshInterval.
+func refresh(provider Provider, logger *slog.Logger, refresh time.Duration) {
+	if refresh == 0 {
+		return
+	}
+
+	provider = noErrNoLimitProvider(provider)
+
+	t := time.NewTicker(refresh)
+	go func() {
+		for range t.C {
+			err := func() (_err error) {
+				snapshot := debug.SetMemoryLimit(-1)
+				defer rollbackOnPanic(logger, snapshot, &_err)
+
+				_, err := updateGoMemLimit(uint64(snapshot), provider, logger)
+				if err != nil {
+					return err
+				}
+
+				return nil
+			}()
+			if err != nil {
+				logger.Error("failed to refresh GOMEMLIMIT", slog.Any("error", err))
+			}
+		}
+	}()
+}
+
+// rollbackOnPanic rollbacks to the snapshot on panic.
+// Since it uses recover, it should be called in a deferred function.
+func rollbackOnPanic(logger *slog.Logger, snapshot int64, err *error) {
+	panicErr := recover()
+	if panicErr != nil {
+		if *err != nil {
+			logger.Error("failed to set GOMEMLIMIT", slog.Any("error", *err))
+		}
+		*err = fmt.Errorf("panic during setting the Go's memory limit, rolling back to previous limit %d: %v",
+			snapshot, panicErr,
+		)
+		debug.SetMemoryLimit(snapshot)
+	}
+}
+
+// SetGoMemLimitWithEnv sets GOMEMLIMIT with the value from the environment variables.
+// Since WithEnv is deprecated, this function is equivalent to SetGoMemLimitWithOpts().
+// Deprecated: use SetGoMemLimitWithOpts instead.
+func SetGoMemLimitWithEnv() {
+	_, _ = SetGoMemLimitWithOpts()
+}
+
+// SetGoMemLimit sets GOMEMLIMIT with the value from the cgroup's memory limit and given ratio.
+func SetGoMemLimit(ratio float64) (int64, error) {
+	return SetGoMemLimitWithOpts(WithRatio(ratio))
+}
+
+// SetGoMemLimitWithProvider sets GOMEMLIMIT with the value from the given provider and ratio.
+func SetGoMemLimitWithProvider(provider Provider, ratio float64) (int64, error) {
+	return SetGoMemLimitWithOpts(WithProvider(provider), WithRatio(ratio))
+}
+
+func noErrNoLimitProvider(provider Provider) Provider {
+	return func() (uint64, error) {
+		limit, err := provider()
+		if errors.Is(err, ErrNoLimit) {
+			return math.MaxInt64, nil
+		}
+		return limit, err
+	}
+}
+
+func capProvider(provider Provider) Provider {
+	return func() (uint64, error) {
+		limit, err := provider()
+		if err != nil {
+			return 0, err
+		} else if limit > math.MaxInt64 {
+			return math.MaxInt64, nil
+		}
+		return limit, nil
+	}
+}

Server/vendor/github.com/KimMachineGun/automemlimit/memlimit/provider.go

@@ -0,0 +1,43 @@
+package memlimit
+
+import (
+	"fmt"
+)
+
+// Provider is a function that returns the memory limit.
+type Provider func() (uint64, error)
+
+// Limit is a helper Provider function that returns the given limit.
+func Limit(limit uint64) func() (uint64, error) {
+	return func() (uint64, error) {
+		return limit, nil
+	}
+}
+
+// ApplyRationA is a helper Provider function that applies the given ratio to the given provider.
+func ApplyRatio(provider Provider, ratio float64) Provider {
+	if ratio == 1 {
+		return provider
+	}
+	return func() (uint64, error) {
+		if ratio <= 0 || ratio > 1 {
+			return 0, fmt.Errorf("invalid ratio: %f, ratio should be in the range (0.0,1.0]", ratio)
+		}
+		limit, err := provider()
+		if err != nil {
+			return 0, err
+		}
+		return uint64(float64(limit) * ratio), nil
+	}
+}
+
+// ApplyFallback is a helper Provider function that sets the fallback provider.
+func ApplyFallback(provider Provider, fallback Provider) Provider {
+	return func() (uint64, error) {
+		limit, err := provider()
+		if err != nil {
+			return fallback()
+		}
+		return limit, nil
+	}
+}