package buf import ( "io" "v2ray.com/core/common/errors" ) // BytesToBufferReader is a Reader that adjusts its reading speed automatically. type BytesToBufferReader struct { io.Reader buffer []byte } // NewBytesToBufferReader returns a new BytesToBufferReader. func NewBytesToBufferReader(reader io.Reader) Reader { return &BytesToBufferReader{ Reader: reader, } } const mediumSize = 8 * 1024 const largeSize = 64 * 1024 func (r *BytesToBufferReader) readSmall() (MultiBuffer, error) { b := New() err := b.Reset(ReadFrom(r.Reader)) if b.IsFull() { r.buffer = make([]byte, mediumSize) } if !b.IsEmpty() { return NewMultiBufferValue(b), nil } b.Release() return nil, err } // ReadMultiBuffer implements Reader. func (r *BytesToBufferReader) ReadMultiBuffer() (MultiBuffer, error) { if r.buffer == nil { return r.readSmall() } nBytes, err := r.Reader.Read(r.buffer) if nBytes > 0 { mb := NewMultiBufferCap(nBytes/Size + 1) mb.Write(r.buffer[:nBytes]) if nBytes == len(r.buffer) && len(r.buffer) == mediumSize { r.buffer = make([]byte, largeSize) } return mb, nil } return nil, err } // BufferedReader is a Reader that keeps its internal buffer. type BufferedReader struct { stream Reader leftOver MultiBuffer buffered bool } // NewBufferedReader returns a new BufferedReader. func NewBufferedReader(reader Reader) *BufferedReader { return &BufferedReader{ stream: reader, buffered: true, } } // SetBuffered sets whether to keep the interal buffer. func (r *BufferedReader) SetBuffered(f bool) { r.buffered = f } // IsBuffered returns true if internal buffer is used. func (r *BufferedReader) IsBuffered() bool { return r.buffered } // 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.leftOver != nil { nBytes, _ := r.leftOver.Read(b) if r.leftOver.IsEmpty() { r.leftOver.Release() r.leftOver = nil } return nBytes, nil } if !r.buffered { if reader, ok := r.stream.(io.Reader); ok { return reader.Read(b) } } mb, err := r.stream.ReadMultiBuffer() if mb != nil { nBytes, _ := mb.Read(b) if !mb.IsEmpty() { r.leftOver = mb } return nBytes, err } return 0, err } // ReadMultiBuffer implements Reader. func (r *BufferedReader) ReadMultiBuffer() (MultiBuffer, error) { if r.leftOver != nil { mb := r.leftOver r.leftOver = nil return mb, nil } return r.stream.ReadMultiBuffer() } // ReadAtMost returns a MultiBuffer with at most size. func (r *BufferedReader) ReadAtMost(size int) (MultiBuffer, error) { if r.leftOver == nil { mb, err := r.stream.ReadMultiBuffer() if mb.IsEmpty() && err != nil { return nil, err } r.leftOver = mb } mb := r.leftOver.SliceBySize(size) if r.leftOver.IsEmpty() { r.leftOver = nil } return mb, nil } func (r *BufferedReader) writeToInternal(writer io.Writer) (int64, error) { mbWriter := NewWriter(writer) totalBytes := int64(0) if r.leftOver != nil { totalBytes += int64(r.leftOver.Len()) if err := mbWriter.WriteMultiBuffer(r.leftOver); err != nil { return 0, err } } for { mb, err := r.stream.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 }