package mux import ( "github.com/xtls/xray-core/common" "github.com/xtls/xray-core/common/buf" "github.com/xtls/xray-core/common/net" "github.com/xtls/xray-core/common/protocol" "github.com/xtls/xray-core/common/serial" ) type Writer struct { dest net.Destination writer buf.Writer id uint16 followup bool hasError bool transferType protocol.TransferType } func NewWriter(id uint16, dest net.Destination, writer buf.Writer, transferType protocol.TransferType) *Writer { return &Writer{ id: id, dest: dest, writer: writer, followup: false, transferType: transferType, } } func NewResponseWriter(id uint16, writer buf.Writer, transferType protocol.TransferType) *Writer { return &Writer{ id: id, writer: writer, followup: true, transferType: transferType, } } func (w *Writer) getNextFrameMeta() FrameMetadata { meta := FrameMetadata{ SessionID: w.id, Target: w.dest, } if w.followup { meta.SessionStatus = SessionStatusKeep } else { w.followup = true meta.SessionStatus = SessionStatusNew } return meta } func (w *Writer) writeMetaOnly() error { meta := w.getNextFrameMeta() b := buf.New() if err := meta.WriteTo(b); err != nil { return err } return w.writer.WriteMultiBuffer(buf.MultiBuffer{b}) } func writeMetaWithFrame(writer buf.Writer, meta FrameMetadata, data buf.MultiBuffer) error { frame := buf.New() if len(data) == 1 { frame.UDP = data[0].UDP } if err := meta.WriteTo(frame); err != nil { return err } if _, err := serial.WriteUint16(frame, uint16(data.Len())); err != nil { return err } mb2 := make(buf.MultiBuffer, 0, len(data)+1) mb2 = append(mb2, frame) mb2 = append(mb2, data...) return writer.WriteMultiBuffer(mb2) } func (w *Writer) writeData(mb buf.MultiBuffer) error { meta := w.getNextFrameMeta() meta.Option.Set(OptionData) return writeMetaWithFrame(w.writer, meta, mb) } // WriteMultiBuffer implements buf.Writer. func (w *Writer) WriteMultiBuffer(mb buf.MultiBuffer) error { defer buf.ReleaseMulti(mb) if mb.IsEmpty() { return w.writeMetaOnly() } for !mb.IsEmpty() { var chunk buf.MultiBuffer if w.transferType == protocol.TransferTypeStream { mb, chunk = buf.SplitSize(mb, 8*1024) } else { mb2, b := buf.SplitFirst(mb) mb = mb2 chunk = buf.MultiBuffer{b} } if err := w.writeData(chunk); err != nil { return err } } return nil } // Close implements common.Closable. func (w *Writer) Close() error { meta := FrameMetadata{ SessionID: w.id, SessionStatus: SessionStatusEnd, } if w.hasError { meta.Option.Set(OptionError) } frame := buf.New() common.Must(meta.WriteTo(frame)) w.writer.WriteMultiBuffer(buf.MultiBuffer{frame}) return nil }