status-go/vendor/github.com/libp2p/go-msgio/protoio/uvarint_writer.go

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//
// 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 (
"io"
"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) {
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
}