blob: ef59bc8883f616ec653dab5a74944c3a7800de90 [file] [log] [blame]
// Copyright 2015 The etcd Authors
//
// 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 rafthttp
import (
"encoding/binary"
"errors"
"io"
"github.com/coreos/etcd/pkg/pbutil"
"github.com/coreos/etcd/raft/raftpb"
)
// messageEncoder is a encoder that can encode all kinds of messages.
// It MUST be used with a paired messageDecoder.
type messageEncoder struct {
w io.Writer
}
func (enc *messageEncoder) encode(m *raftpb.Message) error {
if err := binary.Write(enc.w, binary.BigEndian, uint64(m.Size())); err != nil {
return err
}
_, err := enc.w.Write(pbutil.MustMarshal(m))
return err
}
// messageDecoder is a decoder that can decode all kinds of messages.
type messageDecoder struct {
r io.Reader
}
var (
readBytesLimit uint64 = 512 * 1024 * 1024 // 512 MB
ErrExceedSizeLimit = errors.New("rafthttp: error limit exceeded")
)
func (dec *messageDecoder) decode() (raftpb.Message, error) {
return dec.decodeLimit(readBytesLimit)
}
func (dec *messageDecoder) decodeLimit(numBytes uint64) (raftpb.Message, error) {
var m raftpb.Message
var l uint64
if err := binary.Read(dec.r, binary.BigEndian, &l); err != nil {
return m, err
}
if l > numBytes {
return m, ErrExceedSizeLimit
}
buf := make([]byte, int(l))
if _, err := io.ReadFull(dec.r, buf); err != nil {
return m, err
}
return m, m.Unmarshal(buf)
}