104 lines
2.9 KiB
Go
104 lines
2.9 KiB
Go
// Adapted from gogo/protobuf to use multiformats/go-varint for
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// efficient, interoperable length-prefixing.
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//
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// # 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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//
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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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//
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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 pbio
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import (
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"fmt"
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"io"
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"os"
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"runtime/debug"
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"google.golang.org/protobuf/proto"
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"github.com/multiformats/go-varint"
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)
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type uvarintWriter 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 NewDelimitedWriter(w io.Writer) WriteCloser {
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return &uvarintWriter{w, make([]byte, varint.MaxLenUvarint63), nil}
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}
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func (uw *uvarintWriter) WriteMsg(msg proto.Message) (err error) {
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defer func() {
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if rerr := recover(); rerr != nil {
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fmt.Fprintf(os.Stderr, "caught panic: %s\n%s\n", rerr, debug.Stack())
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err = fmt.Errorf("panic reading message: %s", rerr)
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}
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}()
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var data []byte
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if m, ok := msg.(interface {
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MarshalTo(data []byte) (n int, err error)
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}); ok {
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n, ok := getSize(m)
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if ok {
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if n+varint.MaxLenUvarint63 >= len(uw.buffer) {
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uw.buffer = make([]byte, n+varint.MaxLenUvarint63)
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}
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lenOff := varint.PutUvarint(uw.buffer, uint64(n))
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_, err = m.MarshalTo(uw.buffer[lenOff:])
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if err != nil {
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return err
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}
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_, err = uw.w.Write(uw.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 := varint.PutUvarint(uw.lenBuf, length)
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_, err = uw.w.Write(uw.lenBuf[:n])
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if err != nil {
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return err
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}
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_, err = uw.w.Write(data)
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return err
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}
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func (uw *uvarintWriter) Close() error {
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if closer, ok := uw.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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