| // 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) |
| } |