47 lines
1.5 KiB
Go
47 lines
1.5 KiB
Go
|
// Copyright 2013 Matt T. Proud
|
||
|
|
//
|
||
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
|
// you may not use this file except in compliance with the License.
|
||
|
|
// You may obtain a copy of the License at
|
||
|
|
//
|
||
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
//
|
||
|
|
// Unless required by applicable law or agreed to in writing, software
|
||
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
|
// See the License for the specific language governing permissions and
|
||
|
|
// limitations under the License.
|
||
|
|
|
||
|
|
package pbutil
|
||
|
|
|
||
|
|
import (
|
||
|
|
"encoding/binary"
|
||
|
|
"io"
|
||
|
|
|
||
|
|
"github.com/golang/protobuf/proto"
|
||
|
|
)
|
||
|
|
|
||
|
|
// WriteDelimited encodes and dumps a message to the provided writer prefixed
|
||
|
|
// with a 32-bit varint indicating the length of the encoded message, producing
|
||
|
|
// a length-delimited record stream, which can be used to chain together
|
||
|
|
// encoded messages of the same type together in a file. It returns the total
|
||
|
|
// number of bytes written and any applicable error. This is roughly
|
||
|
|
// equivalent to the companion Java API's MessageLite#writeDelimitedTo.
|
||
|
|
func WriteDelimited(w io.Writer, m proto.Message) (n int, err error) {
|
||
|
|
buffer, err := proto.Marshal(m)
|
||
|
|
if err != nil {
|
||
|
|
return 0, err
|
||
|
|
}
|
||
|
|
|
||
|
|
var buf [binary.MaxVarintLen32]byte
|
||
|
|
encodedLength := binary.PutUvarint(buf[:], uint64(len(buffer)))
|
||
|
|
|
||
|
|
sync, err := w.Write(buf[:encodedLength])
|
||
|
|
if err != nil {
|
||
|
|
return sync, err
|
||
|
|
}
|
||
|
|
|
||
|
|
n, err = w.Write(buffer)
|
||
|
|
return n + sync, err
|
||
|
|
}
|