| // Protocol Buffers for Go with Gadgets |
| // |
| // Copyright (c) 2013, The GoGo Authors. All rights reserved. |
| // http://github.com/gogo/protobuf |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| package io |
| |
| import ( |
| "bufio" |
| "encoding/binary" |
| "errors" |
| "github.com/gogo/protobuf/proto" |
| "io" |
| ) |
| |
| var ( |
| errSmallBuffer = errors.New("Buffer Too Small") |
| errLargeValue = errors.New("Value is Larger than 64 bits") |
| ) |
| |
| func NewDelimitedWriter(w io.Writer) WriteCloser { |
| return &varintWriter{w, make([]byte, 10), nil} |
| } |
| |
| type varintWriter struct { |
| w io.Writer |
| lenBuf []byte |
| buffer []byte |
| } |
| |
| func (this *varintWriter) WriteMsg(msg proto.Message) (err error) { |
| var data []byte |
| if m, ok := msg.(marshaler); ok { |
| n, ok := getSize(m) |
| if !ok { |
| data, err = proto.Marshal(msg) |
| if err != nil { |
| return err |
| } |
| } |
| if n >= len(this.buffer) { |
| this.buffer = make([]byte, n) |
| } |
| _, err = m.MarshalTo(this.buffer) |
| if err != nil { |
| return err |
| } |
| data = this.buffer[:n] |
| } else { |
| data, err = proto.Marshal(msg) |
| if err != nil { |
| return err |
| } |
| } |
| length := uint64(len(data)) |
| n := binary.PutUvarint(this.lenBuf, length) |
| _, err = this.w.Write(this.lenBuf[:n]) |
| if err != nil { |
| return err |
| } |
| _, err = this.w.Write(data) |
| return err |
| } |
| |
| func (this *varintWriter) Close() error { |
| if closer, ok := this.w.(io.Closer); ok { |
| return closer.Close() |
| } |
| return nil |
| } |
| |
| func NewDelimitedReader(r io.Reader, maxSize int) ReadCloser { |
| var closer io.Closer |
| if c, ok := r.(io.Closer); ok { |
| closer = c |
| } |
| return &varintReader{bufio.NewReader(r), nil, maxSize, closer} |
| } |
| |
| type varintReader struct { |
| r *bufio.Reader |
| buf []byte |
| maxSize int |
| closer io.Closer |
| } |
| |
| func (this *varintReader) ReadMsg(msg proto.Message) error { |
| length64, err := binary.ReadUvarint(this.r) |
| if err != nil { |
| return err |
| } |
| length := int(length64) |
| if length < 0 || length > this.maxSize { |
| return io.ErrShortBuffer |
| } |
| if len(this.buf) < length { |
| this.buf = make([]byte, length) |
| } |
| buf := this.buf[:length] |
| if _, err := io.ReadFull(this.r, buf); err != nil { |
| return err |
| } |
| return proto.Unmarshal(buf, msg) |
| } |
| |
| func (this *varintReader) Close() error { |
| if this.closer != nil { |
| return this.closer.Close() |
| } |
| return nil |
| } |