-
Notifications
You must be signed in to change notification settings - Fork 39.3k
/
decoder.go
103 lines (89 loc) · 2.19 KB
/
decoder.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
// Copyright 2015 CoreOS, Inc.
//
// 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 wal
import (
"bufio"
"encoding/binary"
"hash"
"io"
"sync"
"github.com/coreos/etcd/pkg/crc"
"github.com/coreos/etcd/pkg/pbutil"
"github.com/coreos/etcd/raft/raftpb"
"github.com/coreos/etcd/wal/walpb"
)
type decoder struct {
mu sync.Mutex
br *bufio.Reader
c io.Closer
crc hash.Hash32
}
func newDecoder(rc io.ReadCloser) *decoder {
return &decoder{
br: bufio.NewReader(rc),
c: rc,
crc: crc.New(0, crcTable),
}
}
func (d *decoder) decode(rec *walpb.Record) error {
d.mu.Lock()
defer d.mu.Unlock()
rec.Reset()
l, err := readInt64(d.br)
if err != nil {
return err
}
data := make([]byte, l)
if _, err = io.ReadFull(d.br, data); err != nil {
// ReadFull returns io.EOF only if no bytes were read
// the decoder should treat this as an ErrUnexpectedEOF instead.
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
return err
}
if err := rec.Unmarshal(data); err != nil {
return err
}
// skip crc checking if the record type is crcType
if rec.Type == crcType {
return nil
}
d.crc.Write(rec.Data)
return rec.Validate(d.crc.Sum32())
}
func (d *decoder) updateCRC(prevCrc uint32) {
d.crc = crc.New(prevCrc, crcTable)
}
func (d *decoder) lastCRC() uint32 {
return d.crc.Sum32()
}
func (d *decoder) close() error {
return d.c.Close()
}
func mustUnmarshalEntry(d []byte) raftpb.Entry {
var e raftpb.Entry
pbutil.MustUnmarshal(&e, d)
return e
}
func mustUnmarshalState(d []byte) raftpb.HardState {
var s raftpb.HardState
pbutil.MustUnmarshal(&s, d)
return s
}
func readInt64(r io.Reader) (int64, error) {
var n int64
err := binary.Read(r, binary.LittleEndian, &n)
return n, err
}