134 lines
3.5 KiB
Go
134 lines
3.5 KiB
Go
// Protocol Buffers for Go with Gadgets
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//
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// Copyright (c) 2013, The GoGo Authors. All rights reserved.
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// http://github.com/gogo/protobuf
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following disclaimer
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// in the documentation and/or other materials provided with the
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// distribution.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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package io
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import (
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"bufio"
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"encoding/binary"
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"errors"
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"github.com/gogo/protobuf/proto"
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"io"
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)
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var (
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errSmallBuffer = errors.New("Buffer Too Small")
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errLargeValue = errors.New("Value is Larger than 64 bits")
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)
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func NewDelimitedWriter(w io.Writer) WriteCloser {
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return &varintWriter{w, make([]byte, binary.MaxVarintLen64), nil}
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}
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type varintWriter struct {
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w io.Writer
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lenBuf []byte
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buffer []byte
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}
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func (this *varintWriter) WriteMsg(msg proto.Message) (err error) {
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var data []byte
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if m, ok := msg.(marshaler); ok {
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n, ok := getSize(m)
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if ok {
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if n+binary.MaxVarintLen64 >= len(this.buffer) {
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this.buffer = make([]byte, n+binary.MaxVarintLen64)
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}
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lenOff := binary.PutUvarint(this.buffer, uint64(n))
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_, err = m.MarshalTo(this.buffer[lenOff:])
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if err != nil {
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return err
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}
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_, err = this.w.Write(this.buffer[:lenOff+n])
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return err
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}
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}
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// fallback
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data, err = proto.Marshal(msg)
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if err != nil {
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return err
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}
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length := uint64(len(data))
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n := binary.PutUvarint(this.lenBuf, length)
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_, err = this.w.Write(this.lenBuf[:n])
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if err != nil {
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return err
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}
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_, err = this.w.Write(data)
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return err
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}
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func (this *varintWriter) Close() error {
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if closer, ok := this.w.(io.Closer); ok {
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return closer.Close()
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}
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return nil
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}
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func NewDelimitedReader(r io.Reader, maxSize int) ReadCloser {
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var closer io.Closer
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if c, ok := r.(io.Closer); ok {
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closer = c
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}
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return &varintReader{bufio.NewReader(r), nil, maxSize, closer}
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}
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type varintReader struct {
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r *bufio.Reader
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buf []byte
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maxSize int
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closer io.Closer
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}
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func (this *varintReader) ReadMsg(msg proto.Message) error {
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length64, err := binary.ReadUvarint(this.r)
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if err != nil {
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return err
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}
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length := int(length64)
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if length < 0 || length > this.maxSize {
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return io.ErrShortBuffer
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}
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if len(this.buf) < length {
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this.buf = make([]byte, length)
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}
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buf := this.buf[:length]
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if _, err := io.ReadFull(this.r, buf); err != nil {
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return err
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}
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return proto.Unmarshal(buf, msg)
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}
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func (this *varintReader) Close() error {
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if this.closer != nil {
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return this.closer.Close()
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}
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return nil
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}
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