khenaidoo | ab1f7bd | 2019-11-14 14:00:27 -0500 | [diff] [blame] | 1 | // Copyright 2015 The etcd Authors |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | package rafthttp |
| 16 | |
| 17 | import ( |
| 18 | "encoding/binary" |
| 19 | "errors" |
| 20 | "io" |
| 21 | |
| 22 | "go.etcd.io/etcd/pkg/pbutil" |
| 23 | "go.etcd.io/etcd/raft/raftpb" |
| 24 | ) |
| 25 | |
| 26 | // messageEncoder is a encoder that can encode all kinds of messages. |
| 27 | // It MUST be used with a paired messageDecoder. |
| 28 | type messageEncoder struct { |
| 29 | w io.Writer |
| 30 | } |
| 31 | |
| 32 | func (enc *messageEncoder) encode(m *raftpb.Message) error { |
| 33 | if err := binary.Write(enc.w, binary.BigEndian, uint64(m.Size())); err != nil { |
| 34 | return err |
| 35 | } |
| 36 | _, err := enc.w.Write(pbutil.MustMarshal(m)) |
| 37 | return err |
| 38 | } |
| 39 | |
| 40 | // messageDecoder is a decoder that can decode all kinds of messages. |
| 41 | type messageDecoder struct { |
| 42 | r io.Reader |
| 43 | } |
| 44 | |
| 45 | var ( |
| 46 | readBytesLimit uint64 = 512 * 1024 * 1024 // 512 MB |
| 47 | ErrExceedSizeLimit = errors.New("rafthttp: error limit exceeded") |
| 48 | ) |
| 49 | |
| 50 | func (dec *messageDecoder) decode() (raftpb.Message, error) { |
| 51 | return dec.decodeLimit(readBytesLimit) |
| 52 | } |
| 53 | |
| 54 | func (dec *messageDecoder) decodeLimit(numBytes uint64) (raftpb.Message, error) { |
| 55 | var m raftpb.Message |
| 56 | var l uint64 |
| 57 | if err := binary.Read(dec.r, binary.BigEndian, &l); err != nil { |
| 58 | return m, err |
| 59 | } |
| 60 | if l > numBytes { |
| 61 | return m, ErrExceedSizeLimit |
| 62 | } |
| 63 | buf := make([]byte, int(l)) |
| 64 | if _, err := io.ReadFull(dec.r, buf); err != nil { |
| 65 | return m, err |
| 66 | } |
| 67 | return m, m.Unmarshal(buf) |
| 68 | } |