package buf import ( "io" "v2ray.com/core/common" "v2ray.com/core/common/errors" ) func readOne(r io.Reader) (*Buffer, error) { b := New() for i := 0; i < 64; i++ { err := b.Reset(ReadFrom(r)) if !b.IsEmpty() { return b, nil } if err != nil { b.Release() return nil, err } } return nil, newError("Reader returns too many empty payloads.") } // BufferedReader is a Reader that keeps its internal buffer. type BufferedReader struct { // Reader is the underlying reader to be read from Reader Reader // Buffer is the internal buffer to be read from first Buffer MultiBuffer } // BufferedBytes returns the number of bytes that is cached in this reader. func (r *BufferedReader) BufferedBytes() int32 { return r.Buffer.Len() } // ReadByte implements io.ByteReader. func (r *BufferedReader) ReadByte() (byte, error) { var b [1]byte _, err := r.Read(b[:]) return b[0], err } // Read implements io.Reader. It reads from internal buffer first (if available) and then reads from the underlying reader. func (r *BufferedReader) Read(b []byte) (int, error) { if !r.Buffer.IsEmpty() { nBytes, err := r.Buffer.Read(b) common.Must(err) if r.Buffer.IsEmpty() { r.Buffer.Release() r.Buffer = nil } return nBytes, nil } mb, err := r.Reader.ReadMultiBuffer() if err != nil { return 0, err } nBytes, err := mb.Read(b) common.Must(err) if !mb.IsEmpty() { r.Buffer = mb } return nBytes, err } // ReadMultiBuffer implements Reader. func (r *BufferedReader) ReadMultiBuffer() (MultiBuffer, error) { if !r.Buffer.IsEmpty() { mb := r.Buffer r.Buffer = nil return mb, nil } return r.Reader.ReadMultiBuffer() } // ReadAtMost returns a MultiBuffer with at most size. func (r *BufferedReader) ReadAtMost(size int32) (MultiBuffer, error) { if r.Buffer.IsEmpty() { mb, err := r.Reader.ReadMultiBuffer() if mb.IsEmpty() && err != nil { return nil, err } r.Buffer = mb } mb := r.Buffer.SliceBySize(size) if r.Buffer.IsEmpty() { r.Buffer = nil } return mb, nil } func (r *BufferedReader) writeToInternal(writer io.Writer) (int64, error) { mbWriter := NewWriter(writer) totalBytes := int64(0) if r.Buffer != nil { totalBytes += int64(r.Buffer.Len()) if err := mbWriter.WriteMultiBuffer(r.Buffer); err != nil { return 0, err } r.Buffer = nil } for { mb, err := r.Reader.ReadMultiBuffer() if mb != nil { totalBytes += int64(mb.Len()) if werr := mbWriter.WriteMultiBuffer(mb); werr != nil { return totalBytes, err } } if err != nil { return totalBytes, err } } } // WriteTo implements io.WriterTo. func (r *BufferedReader) WriteTo(writer io.Writer) (int64, error) { nBytes, err := r.writeToInternal(writer) if errors.Cause(err) == io.EOF { return nBytes, nil } return nBytes, err } // Close implements io.Closer. func (r *BufferedReader) Close() error { if !r.Buffer.IsEmpty() { r.Buffer.Release() } return common.Close(r.Reader) } type SingleReader struct { io.Reader } func (r *SingleReader) ReadMultiBuffer() (MultiBuffer, error) { b, err := readOne(r.Reader) if err != nil { return nil, err } return NewMultiBufferValue(b), nil }