-
Notifications
You must be signed in to change notification settings - Fork 2
/
codec_decoder.go
114 lines (92 loc) · 2.47 KB
/
codec_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
104
105
106
107
108
109
110
111
112
113
114
package codec
import (
"bytes"
"errors"
"fmt"
"git.golaxy.org/core"
"git.golaxy.org/framework/net/gap"
"io"
)
var (
ErrDataNotEnough = io.ErrShortBuffer // 数据不足
)
// DefaultDecoder 默认消息包解码器
func DefaultDecoder() Decoder {
return MakeDecoder(gap.DefaultMsgCreator())
}
// MakeDecoder 创建消息包解码器
func MakeDecoder(mc gap.IMsgCreator) Decoder {
if mc == nil {
panic(fmt.Errorf("gap: %w: mc is nil", core.ErrArgs))
}
return Decoder{
MsgCreator: mc,
}
}
// Decoder 消息包解码器
type Decoder struct {
MsgCreator gap.IMsgCreator // 消息对象构建器
buffer bytes.Buffer // buffer
}
// Write implements io.Writer
func (d *Decoder) Write(p []byte) (int, error) {
return d.buffer.Write(p)
}
// ReadFrom implements io.ReaderFrom
func (d *Decoder) ReadFrom(r io.Reader) (int64, error) {
if r == nil {
return 0, fmt.Errorf("gap: %w: r is nil", core.ErrArgs)
}
var buff [bytes.MinRead]byte
n, err := r.Read(buff[:])
if n > 0 {
d.buffer.Write(buff[:n])
}
return int64(n), err
}
// Reset 重置缓存
func (d *Decoder) Reset() {
d.buffer.Reset()
}
// Decode 从缓存,解码消息包
func (d *Decoder) Decode() (gap.MsgPacket, error) {
return d.DecodeBuff(&d.buffer)
}
// DecodeBuff 从指定buff,解码消息包
func (d Decoder) DecodeBuff(buff *bytes.Buffer) (gap.MsgPacket, error) {
mp, n, err := d.decode(buff.Bytes())
buff.Next(n)
return mp, err
}
// DecodeBytes 从指定bytes,解码消息包
func (d Decoder) DecodeBytes(data []byte) (gap.MsgPacket, error) {
mp, _, err := d.decode(data)
return mp, err
}
// decode 解码消息包
func (d Decoder) decode(data []byte) (gap.MsgPacket, int, error) {
if d.MsgCreator == nil {
return gap.MsgPacket{}, 0, errors.New("gap: setting MsgCreator is nil")
}
mp := gap.MsgPacket{}
// 读取消息头
n, err := mp.Head.Write(data)
if err != nil {
return gap.MsgPacket{}, 0, fmt.Errorf("gap: read msg-packet-head failed, %w", err)
}
if len(data) < int(mp.Head.Len) {
return gap.MsgPacket{}, 0, fmt.Errorf("gap: %w (%d < %d)", ErrDataNotEnough, len(data), mp.Head.Len)
}
// 创建消息体
msg, err := d.MsgCreator.New(mp.Head.MsgId)
if err != nil {
return gap.MsgPacket{}, int(mp.Head.Len), fmt.Errorf("gap: new msg failed, %w (%d)", err, mp.Head.MsgId)
}
// 读取消息
_, err = msg.Write(data[n:])
if err != nil {
return gap.MsgPacket{}, int(mp.Head.Len), fmt.Errorf("gap: read msg failed, %w", err)
}
mp.Msg = msg
return mp, int(mp.Head.Len), nil
}