reorg chan reader

common/io/chan_reader.go

@@ -0,0 +1,66 @@
+package io
+
+import (
+	"io"
+	"sync"
+
+	"github.com/v2ray/v2ray-core/common/alloc"
+)
+
+type ChanReader struct {
+	sync.Mutex
+	stream  Reader
+	current *alloc.Buffer
+	eof     bool
+}
+
+func NewChanReader(stream Reader) *ChanReader {
+	this := &ChanReader{
+		stream: stream,
+	}
+	this.Fill()
+	return this
+}
+
+// @Private
+func (this *ChanReader) Fill() {
+	b, err := this.stream.Read()
+	this.current = b
+	if err != nil {
+		this.eof = true
+		this.current = nil
+	}
+}
+
+func (this *ChanReader) Read(b []byte) (int, error) {
+	if this.eof {
+		return 0, io.EOF
+	}
+
+	this.Lock()
+	defer this.Unlock()
+	if this.current == nil {
+		this.Fill()
+		if this.eof {
+			return 0, io.EOF
+		}
+	}
+	nBytes := copy(b, this.current.Value)
+	if nBytes == this.current.Len() {
+		this.current.Release()
+		this.current = nil
+	} else {
+		this.current.SliceFrom(nBytes)
+	}
+	return nBytes, nil
+}
+
+func (this *ChanReader) Release() {
+	this.Lock()
+	defer this.Unlock()
+
+	this.eof = true
+	this.current.Release()
+	this.current = nil
+	this.stream = nil
+}