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