/usr/share/gocode/src/github.com/jwilder/encoding/simple9/encoding.go is in golang-github-jwilder-encoding-dev 0.0~git20170811.b4e1701-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 | package simple9
import "fmt"
type packing struct {
n, bit int
unpack func(uint32, []uint32)
pack func([]uint32) uint32
}
var selector [9]packing = [9]packing{
packing{28, 1, unpack28, pack28},
packing{14, 2, unpack14, pack14},
packing{9, 3, unpack9, pack9},
packing{7, 4, unpack7, pack7},
packing{5, 5, unpack5, pack5},
packing{4, 7, unpack4, pack4},
packing{3, 9, unpack3, pack3},
packing{2, 14, unpack2, pack2},
packing{1, 28, unpack1, pack1},
}
// EncodeAll returns a packed slice of the values from src. It a value is over
// 1 << 28, an error is returned.
func EncodeAll(src []uint32) ([]uint32, error) {
i := 0
dst := make([]uint32, len(src))
j := 0
for {
if i >= len(src) {
break
}
remaining := src[i:]
if canPack(remaining, 1, 28) {
dst[j] = pack28(src[i : i+28])
i += 28
} else if canPack(remaining, 2, 14) {
dst[j] = pack14(src[i : i+14])
i += 14
} else if canPack(remaining, 3, 9) {
dst[j] = pack9(src[i : i+9])
i += 9
} else if canPack(remaining, 4, 7) {
dst[j] = pack7(src[i : i+7])
i += 7
} else if canPack(remaining, 5, 5) {
dst[j] = pack5(src[i : i+5])
i += 5
} else if canPack(remaining, 7, 4) {
dst[j] = pack4(src[i : i+4])
i += 4
} else if canPack(remaining, 9, 3) {
dst[j] = pack3(src[i : i+3])
i += 3
} else if canPack(remaining, 14, 2) {
dst[j] = pack2(src[i : i+2])
i += 2
} else if canPack(remaining, 28, 1) {
dst[j] = pack1(src[i : i+1])
i += 1
} else {
return nil, fmt.Errorf("value out of bounds")
}
j += 1
}
return dst[:j], nil
}
// DecodeAll returns the uncompressed values from in
func DecodeAll(dst, src []uint32) error {
j := 0
for _, v := range src {
sel := v >> 28
if sel >= 9 {
return fmt.Errorf("invalid selector value: %b", sel)
}
selector[sel].unpack(v, dst[j:])
j += selector[sel].n
}
return nil
}
// returns true if the next n values in in can be packed using bits bits
// per value.
func canPack(src []uint32, bits, n int) bool {
if len(src) < n {
return false
}
end := len(src)
if n < end {
end = n
}
max := uint32((2 << uint32(bits-1)) - 1)
for i := 0; i < end; i++ {
if src[i] > max {
return false
}
}
return true
}
// pack28 packs 28 values from in using 1 bit each
func pack28(in []uint32) uint32 {
return in[0] |
in[1]<<1 |
in[2]<<2 |
in[3]<<3 |
in[4]<<4 |
in[5]<<5 |
in[6]<<6 |
in[7]<<7 |
in[8]<<8 |
in[9]<<9 |
in[10]<<10 |
in[11]<<11 |
in[12]<<12 |
in[13]<<13 |
in[14]<<14 |
in[15]<<15 |
in[16]<<16 |
in[17]<<17 |
in[18]<<18 |
in[19]<<19 |
in[20]<<20 |
in[21]<<21 |
in[22]<<22 |
in[23]<<23 |
in[24]<<24 |
in[25]<<25 |
in[26]<<26 |
in[27]<<27
}
// pack14 packs 14 values from in using 2 bits each
func pack14(in []uint32) uint32 {
return 1<<28 |
in[0] |
in[1]<<2 |
in[2]<<4 |
in[3]<<6 |
in[4]<<8 |
in[5]<<10 |
in[6]<<12 |
in[7]<<14 |
in[8]<<16 |
in[9]<<18 |
in[10]<<20 |
in[11]<<22 |
in[12]<<24 |
in[13]<<26
}
// pack9 packs 9 values from in using 3 bits each
func pack9(in []uint32) uint32 {
return 2<<28 |
in[0]<<1 |
in[1]<<4 |
in[2]<<7 |
in[3]<<10 |
in[4]<<13 |
in[5]<<16 |
in[6]<<19 |
in[7]<<22 |
in[8]<<25
}
// pack7 packs 7 values from in using 4 bits each
func pack7(in []uint32) uint32 {
return 3<<28 |
in[0] |
in[1]<<4 |
in[2]<<8 |
in[3]<<12 |
in[4]<<16 |
in[5]<<20 |
in[6]<<24
}
// pack5 packs 5 values from in using 5 bits each
func pack5(in []uint32) uint32 {
return 4<<28 |
in[0]<<3 |
in[1]<<8 |
in[2]<<13 |
in[3]<<18 |
in[4]<<23
}
// pack4 packs 4 values from in using 7 bits each
func pack4(in []uint32) uint32 {
return 5<<28 |
in[0] |
in[1]<<7 |
in[2]<<14 |
in[3]<<21
}
// pack3 packs 3 values from in using 9 bits each
func pack3(in []uint32) uint32 {
return 6<<28 |
in[0]<<1 |
in[1]<<10 |
in[2]<<19
}
// pack2 packs 2 values from in using 14 bits each
func pack2(in []uint32) uint32 {
return 7<<28 |
in[0] |
in[1]<<14
}
// pack1 packs 1 value from in using 28 bits
func pack1(in []uint32) uint32 {
return 8<<28 |
in[0]
}
func unpack28(in uint32, out []uint32) {
out[0] = (in >> 27) & 1
out[1] = (in >> 26) & 1
out[2] = (in >> 25) & 1
out[3] = (in >> 24) & 1
out[4] = (in >> 23) & 1
out[5] = (in >> 22) & 1
out[6] = (in >> 21) & 1
out[7] = (in >> 20) & 1
out[8] = (in >> 19) & 1
out[9] = (in >> 18) & 1
out[10] = (in >> 17) & 1
out[11] = (in >> 16) & 1
out[12] = (in >> 15) & 1
out[13] = (in >> 14) & 1
out[14] = (in >> 13) & 1
out[15] = (in >> 12) & 1
out[16] = (in >> 11) & 1
out[17] = (in >> 10) & 1
out[18] = (in >> 9) & 1
out[19] = (in >> 8) & 1
out[20] = (in >> 7) & 1
out[21] = (in >> 6) & 1
out[22] = (in >> 5) & 1
out[23] = (in >> 4) & 1
out[24] = (in >> 3) & 1
out[25] = (in >> 2) & 1
out[26] = (in >> 1) & 1
out[27] = in & 1
}
func unpack14(in uint32, out []uint32) {
out[0] = (in >> 26) & 3
out[1] = (in >> 24) & 3
out[2] = (in >> 22) & 3
out[3] = (in >> 20) & 3
out[4] = (in >> 18) & 3
out[5] = (in >> 16) & 3
out[6] = (in >> 14) & 3
out[7] = (in >> 12) & 3
out[8] = (in >> 10) & 3
out[9] = (in >> 8) & 3
out[10] = (in >> 6) & 3
out[11] = (in >> 4) & 3
out[12] = (in >> 2) & 3
out[13] = in & 3
}
func unpack9(in uint32, out []uint32) {
out[0] = (in >> 25) & 7
out[1] = (in >> 22) & 7
out[2] = (in >> 19) & 7
out[3] = (in >> 16) & 7
out[4] = (in >> 13) & 7
out[5] = (in >> 10) & 7
out[6] = (in >> 7) & 7
out[7] = (in >> 4) & 7
out[8] = (in >> 1) & 7
}
func unpack7(in uint32, out []uint32) {
out[0] = (in >> 24) & 15
out[1] = (in >> 20) & 15
out[2] = (in >> 16) & 15
out[3] = (in >> 12) & 15
out[4] = (in >> 8) & 15
out[5] = (in >> 4) & 15
out[6] = in & 15
}
func unpack5(in uint32, out []uint32) {
out[0] = (in >> 23) & 31
out[1] = (in >> 18) & 31
out[2] = (in >> 13) & 31
out[3] = (in >> 8) & 31
out[4] = (in >> 3) & 31
}
func unpack4(in uint32, out []uint32) {
out[0] = (in >> 21) & 63
out[1] = (in >> 14) & 63
out[2] = (in >> 7) & 63
out[3] = in & 63
}
func unpack3(in uint32, out []uint32) {
out[0] = (in >> 19) & 511
out[1] = (in >> 10) & 511
out[2] = (in >> 1) & 511
}
func unpack2(in uint32, out []uint32) {
out[0] = (in >> 14) & 16383
out[1] = in & 16383
}
func unpack1(in uint32, out []uint32) {
out[0] = in & 268435455
}
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