-
Notifications
You must be signed in to change notification settings - Fork 0
/
bitslice.go
226 lines (204 loc) · 4.58 KB
/
bitslice.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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
package bitslice
import (
"bytes"
"encoding/binary"
"io"
)
//BitSlice slice with bits
type BitSlice struct {
Slice []bool
ByteOrder binary.ByteOrder
}
//NewEmptyBitSlice returns empty BitSlice
func NewEmptyBitSlice(bo binary.ByteOrder) *BitSlice {
return &BitSlice{
ByteOrder: bo,
}
}
//NewBitSliceFromAllReader returns BitSlice exported from all io.Reader
func NewBitSliceFromAllReader(r io.Reader, bo binary.ByteOrder) (*BitSlice, error) {
bs := &BitSlice{
ByteOrder: bo,
}
var b byte
cnt := 0
for {
err := binary.Read(r, bo, &b)
if err != nil {
if err == io.EOF {
break
}
return nil, err
}
newByte := make([]bool, 8)
bs.Slice = append(bs.Slice, newByte...)
for j := range [8]struct{}{} {
bs.Slice[8*cnt+j] = (b<<7)>>7 == 1
b = b >> 1
}
cnt++
}
return bs, nil
}
//NewBitSliceFromBool returns BitSlice exported from []bool
func NewBitSliceFromBool(b []bool, bo binary.ByteOrder) *BitSlice {
return &BitSlice{
b, bo,
}
}
//NewBitSliceFromBytes returns BitSlice exported from []byte
func NewBitSliceFromBytes(b []byte, bo binary.ByteOrder) (*BitSlice, error) {
buf := bytes.NewBuffer(b)
return NewBitSliceFromReader(buf, bo, uint(len(b)))
}
//NewBitSliceFromReader returns BitSlice exported from io.Reader
func NewBitSliceFromReader(r io.Reader, bo binary.ByteOrder, bytesSize uint) (*BitSlice, error) {
var inBytes = make([]byte, bytesSize)
err := binary.Read(r, bo, &inBytes)
if err != nil {
return nil, err
}
bs := &BitSlice{
Slice: make([]bool, bytesSize*8),
ByteOrder: bo,
}
lFunc := func(bPtr *byte, index int) {
bs.Slice[index] = (*bPtr<<7)>>7 == 1
*bPtr = *bPtr >> 1
}
bFunc := func(bPtr *byte, index int) {
bs.Slice[index] = *bPtr>>7 == 1
*bPtr = *bPtr << 1
}
nowFunc := lFunc
if bo.String() == binary.BigEndian.String() {
nowFunc = bFunc
}
for i, b := range inBytes {
for j := range [8]struct{}{} {
nowFunc(&b, 8*i+j)
}
}
return bs, nil
}
//ToBytes returns []byte from BitSlice
func (s BitSlice) ToBytes() []byte {
var packed []byte
var flagTrue byte
var flagTrueDefault byte = 1
lFunc := func() {
flagTrue = flagTrue << 1
}
bFunc := func() {
flagTrue = flagTrue >> 1
}
nowFunc := lFunc
if s.ByteOrder.String() == binary.BigEndian.String() {
nowFunc = bFunc
flagTrueDefault = flagTrueDefault << 7
}
flagTrue = flagTrueDefault
for i, flag := range s.Slice {
if i%8 == 0 {
packed = append(packed, 0)
flagTrue = flagTrueDefault
}
if flag {
packed[i/8] |= flagTrue
}
nowFunc()
}
return packed
}
//ToBuffer write bytes from BitSlice to io.Writer
func (s BitSlice) ToBuffer(w io.Writer) error {
err := binary.Write(w, s.ByteOrder, s.ToBytes())
if err != nil {
return err
}
return nil
}
//Len return length of slice
func (s BitSlice) Len() int {
return len(s.Slice)
}
//LenBytes return length of slice
func (s BitSlice) LenBytes() int {
lenBits := s.Len()
lenBytes := lenBits / 8
if lenBits%8 > 0 {
lenBytes += 1
}
return lenBytes
}
//ShiftLeft returns shifted BitSlice, like << operation
func (s BitSlice) ShiftLeft(val int) BitSlice {
if val == 0 {
return s
}
if val < 0 {
return s.ShiftRight(-val)
}
newSlice := s
newSlice.Slice = make([]bool, s.Len())
for i, bit := range s.Slice[val:] {
newSlice.Slice[i] = bit
}
return newSlice
}
//ShiftRight returns shifted BitSlice, like >> operation
func (s BitSlice) ShiftRight(val int) BitSlice {
if val == 0 {
return s
}
if val < 0 {
return s.ShiftLeft(-val)
}
newSlice := s
sLen := s.Len()
newSlice.Slice = make([]bool, sLen)
ns := s.Slice[:sLen-val]
nsLen := len(ns)
for i, bit := range ns {
newSlice.Slice[sLen-nsLen+i] = bit
}
return newSlice
}
//Inverse returns inverted BitSlice
func (s BitSlice) Inverse() BitSlice {
newSlice := s
for i, bit := range newSlice.Slice {
newSlice.Slice[i] = !bit
}
return newSlice
}
//Or returns combine of 2 BitSlice, like | operation
func (s BitSlice) Or(bs BitSlice) BitSlice {
smallSlice := bs
bigSlice := s
if bsLen := bs.Len(); bsLen > s.Len() {
smallSlice = s
bigSlice = bs
}
for i := range smallSlice.Slice {
smallSlice.Slice[i] = smallSlice.Slice[i] || bigSlice.Slice[i]
}
smallSlice.ByteOrder = s.ByteOrder
return smallSlice
}
//And returns combine of 2 BitSlice, like & operation
func (s BitSlice) And(bs BitSlice) BitSlice {
sliceLen := s.Len()
smallSlice := bs
bigSlice := s
if bsLen := bs.Len(); bsLen > s.Len() {
sliceLen = bsLen
smallSlice = s
bigSlice = bs
}
newSlice := BitSlice{make([]bool, sliceLen), s.ByteOrder}
for i := range smallSlice.Slice {
newSlice.Slice[i] = smallSlice.Slice[i] && bigSlice.Slice[i]
}
return newSlice
}