-
Notifications
You must be signed in to change notification settings - Fork 4.6k
/
chunk.go
executable file
·160 lines (132 loc) · 3.57 KB
/
chunk.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
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
package crypto
import (
"encoding/binary"
"io"
"v2ray.com/core/common"
"v2ray.com/core/common/buf"
)
// ChunkSizeDecoder is a utility class to decode size value from bytes.
type ChunkSizeDecoder interface {
SizeBytes() int32
Decode([]byte) (uint16, error)
}
// ChunkSizeEncoder is a utility class to encode size value into bytes.
type ChunkSizeEncoder interface {
SizeBytes() int32
Encode(uint16, []byte) []byte
}
type PaddingLengthGenerator interface {
MaxPaddingLen() uint16
NextPaddingLen() uint16
}
type PlainChunkSizeParser struct{}
func (PlainChunkSizeParser) SizeBytes() int32 {
return 2
}
func (PlainChunkSizeParser) Encode(size uint16, b []byte) []byte {
binary.BigEndian.PutUint16(b, size)
return b[:2]
}
func (PlainChunkSizeParser) Decode(b []byte) (uint16, error) {
return binary.BigEndian.Uint16(b), nil
}
type AEADChunkSizeParser struct {
Auth *AEADAuthenticator
}
func (p *AEADChunkSizeParser) SizeBytes() int32 {
return 2 + int32(p.Auth.Overhead())
}
func (p *AEADChunkSizeParser) Encode(size uint16, b []byte) []byte {
binary.BigEndian.PutUint16(b, size-uint16(p.Auth.Overhead()))
b, err := p.Auth.Seal(b[:0], b[:2])
common.Must(err)
return b
}
func (p *AEADChunkSizeParser) Decode(b []byte) (uint16, error) {
b, err := p.Auth.Open(b[:0], b)
if err != nil {
return 0, err
}
return binary.BigEndian.Uint16(b) + uint16(p.Auth.Overhead()), nil
}
type ChunkStreamReader struct {
sizeDecoder ChunkSizeDecoder
reader *buf.BufferedReader
buffer []byte
leftOverSize int32
maxNumChunk uint32
numChunk uint32
}
func NewChunkStreamReader(sizeDecoder ChunkSizeDecoder, reader io.Reader) *ChunkStreamReader {
return NewChunkStreamReaderWithChunkCount(sizeDecoder, reader, 0)
}
func NewChunkStreamReaderWithChunkCount(sizeDecoder ChunkSizeDecoder, reader io.Reader, maxNumChunk uint32) *ChunkStreamReader {
r := &ChunkStreamReader{
sizeDecoder: sizeDecoder,
buffer: make([]byte, sizeDecoder.SizeBytes()),
maxNumChunk: maxNumChunk,
}
if breader, ok := reader.(*buf.BufferedReader); ok {
r.reader = breader
} else {
r.reader = &buf.BufferedReader{Reader: buf.NewReader(reader)}
}
return r
}
func (r *ChunkStreamReader) readSize() (uint16, error) {
if _, err := io.ReadFull(r.reader, r.buffer); err != nil {
return 0, err
}
return r.sizeDecoder.Decode(r.buffer)
}
func (r *ChunkStreamReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
size := r.leftOverSize
if size == 0 {
r.numChunk++
if r.maxNumChunk > 0 && r.numChunk > r.maxNumChunk {
return nil, io.EOF
}
nextSize, err := r.readSize()
if err != nil {
return nil, err
}
if nextSize == 0 {
return nil, io.EOF
}
size = int32(nextSize)
}
r.leftOverSize = size
mb, err := r.reader.ReadAtMost(size)
if !mb.IsEmpty() {
r.leftOverSize -= mb.Len()
return mb, nil
}
return nil, err
}
type ChunkStreamWriter struct {
sizeEncoder ChunkSizeEncoder
writer buf.Writer
}
func NewChunkStreamWriter(sizeEncoder ChunkSizeEncoder, writer io.Writer) *ChunkStreamWriter {
return &ChunkStreamWriter{
sizeEncoder: sizeEncoder,
writer: buf.NewWriter(writer),
}
}
func (w *ChunkStreamWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
const sliceSize = 8192
mbLen := mb.Len()
mb2Write := make(buf.MultiBuffer, 0, mbLen/buf.Size+mbLen/sliceSize+2)
for {
mb2, slice := buf.SplitSize(mb, sliceSize)
mb = mb2
b := buf.New()
w.sizeEncoder.Encode(uint16(slice.Len()), b.Extend(w.sizeEncoder.SizeBytes()))
mb2Write = append(mb2Write, b)
mb2Write = append(mb2Write, slice...)
if mb.IsEmpty() {
break
}
}
return w.writer.WriteMultiBuffer(mb2Write)
}