package io import ( "io" "sync" "v2ray.com/core/common/alloc" ) type BufferedWriter struct { sync.Mutex writer io.Writer buffer *alloc.Buffer cached bool } func NewBufferedWriter(rawWriter io.Writer) *BufferedWriter { return &BufferedWriter{ writer: rawWriter, buffer: alloc.NewBuffer().Clear(), cached: true, } } func (this *BufferedWriter) ReadFrom(reader io.Reader) (int64, error) { this.Lock() defer this.Unlock() if this.writer == nil { return 0, io.EOF } totalBytes := int64(0) for { nBytes, err := this.buffer.FillFrom(reader) totalBytes += int64(nBytes) if err != nil { if err == io.EOF { return totalBytes, nil } return totalBytes, err } this.FlushWithoutLock() } } func (this *BufferedWriter) Write(b []byte) (int, error) { this.Lock() defer this.Unlock() if this.writer == nil { return 0, io.EOF } if !this.cached { return this.writer.Write(b) } nBytes, _ := this.buffer.Write(b) if this.buffer.IsFull() { this.FlushWithoutLock() } return nBytes, nil } func (this *BufferedWriter) Flush() error { this.Lock() defer this.Unlock() if this.writer == nil { return io.EOF } return this.FlushWithoutLock() } func (this *BufferedWriter) FlushWithoutLock() error { defer this.buffer.Clear() for !this.buffer.IsEmpty() { nBytes, err := this.writer.Write(this.buffer.Value) if err != nil { return err } this.buffer.SliceFrom(nBytes) } return nil } func (this *BufferedWriter) Cached() bool { return this.cached } func (this *BufferedWriter) SetCached(cached bool) { this.cached = cached if !cached && !this.buffer.IsEmpty() { this.Flush() } } func (this *BufferedWriter) Release() { this.Flush() this.Lock() defer this.Unlock() this.buffer.Release() this.buffer = nil this.writer = nil }