package kcp import ( "io" "sync" "v2ray.com/core/common/alloc" v2io "v2ray.com/core/common/io" "v2ray.com/core/transport/internet" ) type SegmentWriter interface { Write(seg Segment) } type BufferedSegmentWriter struct { sync.Mutex mtu uint32 buffer *alloc.Buffer writer v2io.Writer } func NewSegmentWriter(writer *AuthenticationWriter) *BufferedSegmentWriter { return &BufferedSegmentWriter{ mtu: writer.Mtu(), writer: writer, } } func (this *BufferedSegmentWriter) Write(seg Segment) { this.Lock() defer this.Unlock() nBytes := seg.ByteSize() if uint32(this.buffer.Len()+nBytes) > this.mtu { this.FlushWithoutLock() } if this.buffer == nil { this.buffer = alloc.NewLocalBuffer(2048).Clear() } this.buffer.Value = seg.Bytes(this.buffer.Value) } func (this *BufferedSegmentWriter) FlushWithoutLock() { go this.writer.Write(this.buffer) this.buffer = nil } func (this *BufferedSegmentWriter) Flush() { this.Lock() defer this.Unlock() if this.buffer.Len() == 0 { return } this.FlushWithoutLock() } type AuthenticationWriter struct { Authenticator internet.Authenticator Writer io.Writer Config *Config } func (this *AuthenticationWriter) Write(payload *alloc.Buffer) error { defer payload.Release() this.Authenticator.Seal(payload) _, err := this.Writer.Write(payload.Value) return err } func (this *AuthenticationWriter) Release() {} func (this *AuthenticationWriter) Mtu() uint32 { return this.Config.Mtu.GetValue() - uint32(this.Authenticator.Overhead()) }