kesavand | c71914f | 2022-03-25 11:19:03 +0530 | [diff] [blame] | 1 | // Copyright 2019+ Klaus Post. All rights reserved. |
| 2 | // License information can be found in the LICENSE file. |
| 3 | // Based on work by Yann Collet, released under BSD License. |
| 4 | |
| 5 | package zstd |
| 6 | |
| 7 | import "fmt" |
| 8 | |
| 9 | const ( |
| 10 | dFastLongTableBits = 17 // Bits used in the long match table |
| 11 | dFastLongTableSize = 1 << dFastLongTableBits // Size of the table |
| 12 | dFastLongTableMask = dFastLongTableSize - 1 // Mask for table indices. Redundant, but can eliminate bounds checks. |
| 13 | dFastLongLen = 8 // Bytes used for table hash |
| 14 | |
| 15 | dLongTableShardCnt = 1 << (dFastLongTableBits - dictShardBits) // Number of shards in the table |
| 16 | dLongTableShardSize = dFastLongTableSize / tableShardCnt // Size of an individual shard |
| 17 | |
| 18 | dFastShortTableBits = tableBits // Bits used in the short match table |
| 19 | dFastShortTableSize = 1 << dFastShortTableBits // Size of the table |
| 20 | dFastShortTableMask = dFastShortTableSize - 1 // Mask for table indices. Redundant, but can eliminate bounds checks. |
| 21 | dFastShortLen = 5 // Bytes used for table hash |
| 22 | |
| 23 | ) |
| 24 | |
| 25 | type doubleFastEncoder struct { |
| 26 | fastEncoder |
| 27 | longTable [dFastLongTableSize]tableEntry |
| 28 | } |
| 29 | |
| 30 | type doubleFastEncoderDict struct { |
| 31 | fastEncoderDict |
| 32 | longTable [dFastLongTableSize]tableEntry |
| 33 | dictLongTable []tableEntry |
| 34 | longTableShardDirty [dLongTableShardCnt]bool |
| 35 | } |
| 36 | |
| 37 | // Encode mimmics functionality in zstd_dfast.c |
| 38 | func (e *doubleFastEncoder) Encode(blk *blockEnc, src []byte) { |
| 39 | const ( |
| 40 | // Input margin is the number of bytes we read (8) |
| 41 | // and the maximum we will read ahead (2) |
| 42 | inputMargin = 8 + 2 |
| 43 | minNonLiteralBlockSize = 16 |
| 44 | ) |
| 45 | |
| 46 | // Protect against e.cur wraparound. |
| 47 | for e.cur >= bufferReset { |
| 48 | if len(e.hist) == 0 { |
| 49 | for i := range e.table[:] { |
| 50 | e.table[i] = tableEntry{} |
| 51 | } |
| 52 | for i := range e.longTable[:] { |
| 53 | e.longTable[i] = tableEntry{} |
| 54 | } |
| 55 | e.cur = e.maxMatchOff |
| 56 | break |
| 57 | } |
| 58 | // Shift down everything in the table that isn't already too far away. |
| 59 | minOff := e.cur + int32(len(e.hist)) - e.maxMatchOff |
| 60 | for i := range e.table[:] { |
| 61 | v := e.table[i].offset |
| 62 | if v < minOff { |
| 63 | v = 0 |
| 64 | } else { |
| 65 | v = v - e.cur + e.maxMatchOff |
| 66 | } |
| 67 | e.table[i].offset = v |
| 68 | } |
| 69 | for i := range e.longTable[:] { |
| 70 | v := e.longTable[i].offset |
| 71 | if v < minOff { |
| 72 | v = 0 |
| 73 | } else { |
| 74 | v = v - e.cur + e.maxMatchOff |
| 75 | } |
| 76 | e.longTable[i].offset = v |
| 77 | } |
| 78 | e.cur = e.maxMatchOff |
| 79 | break |
| 80 | } |
| 81 | |
| 82 | s := e.addBlock(src) |
| 83 | blk.size = len(src) |
| 84 | if len(src) < minNonLiteralBlockSize { |
| 85 | blk.extraLits = len(src) |
| 86 | blk.literals = blk.literals[:len(src)] |
| 87 | copy(blk.literals, src) |
| 88 | return |
| 89 | } |
| 90 | |
| 91 | // Override src |
| 92 | src = e.hist |
| 93 | sLimit := int32(len(src)) - inputMargin |
| 94 | // stepSize is the number of bytes to skip on every main loop iteration. |
| 95 | // It should be >= 1. |
| 96 | const stepSize = 1 |
| 97 | |
| 98 | const kSearchStrength = 8 |
| 99 | |
| 100 | // nextEmit is where in src the next emitLiteral should start from. |
| 101 | nextEmit := s |
| 102 | cv := load6432(src, s) |
| 103 | |
| 104 | // Relative offsets |
| 105 | offset1 := int32(blk.recentOffsets[0]) |
| 106 | offset2 := int32(blk.recentOffsets[1]) |
| 107 | |
| 108 | addLiterals := func(s *seq, until int32) { |
| 109 | if until == nextEmit { |
| 110 | return |
| 111 | } |
| 112 | blk.literals = append(blk.literals, src[nextEmit:until]...) |
| 113 | s.litLen = uint32(until - nextEmit) |
| 114 | } |
| 115 | if debugEncoder { |
| 116 | println("recent offsets:", blk.recentOffsets) |
| 117 | } |
| 118 | |
| 119 | encodeLoop: |
| 120 | for { |
| 121 | var t int32 |
| 122 | // We allow the encoder to optionally turn off repeat offsets across blocks |
| 123 | canRepeat := len(blk.sequences) > 2 |
| 124 | |
| 125 | for { |
| 126 | if debugAsserts && canRepeat && offset1 == 0 { |
| 127 | panic("offset0 was 0") |
| 128 | } |
| 129 | |
| 130 | nextHashS := hashLen(cv, dFastShortTableBits, dFastShortLen) |
| 131 | nextHashL := hashLen(cv, dFastLongTableBits, dFastLongLen) |
| 132 | candidateL := e.longTable[nextHashL] |
| 133 | candidateS := e.table[nextHashS] |
| 134 | |
| 135 | const repOff = 1 |
| 136 | repIndex := s - offset1 + repOff |
| 137 | entry := tableEntry{offset: s + e.cur, val: uint32(cv)} |
| 138 | e.longTable[nextHashL] = entry |
| 139 | e.table[nextHashS] = entry |
| 140 | |
| 141 | if canRepeat { |
| 142 | if repIndex >= 0 && load3232(src, repIndex) == uint32(cv>>(repOff*8)) { |
| 143 | // Consider history as well. |
| 144 | var seq seq |
| 145 | lenght := 4 + e.matchlen(s+4+repOff, repIndex+4, src) |
| 146 | |
| 147 | seq.matchLen = uint32(lenght - zstdMinMatch) |
| 148 | |
| 149 | // We might be able to match backwards. |
| 150 | // Extend as long as we can. |
| 151 | start := s + repOff |
| 152 | // We end the search early, so we don't risk 0 literals |
| 153 | // and have to do special offset treatment. |
| 154 | startLimit := nextEmit + 1 |
| 155 | |
| 156 | tMin := s - e.maxMatchOff |
| 157 | if tMin < 0 { |
| 158 | tMin = 0 |
| 159 | } |
| 160 | for repIndex > tMin && start > startLimit && src[repIndex-1] == src[start-1] && seq.matchLen < maxMatchLength-zstdMinMatch-1 { |
| 161 | repIndex-- |
| 162 | start-- |
| 163 | seq.matchLen++ |
| 164 | } |
| 165 | addLiterals(&seq, start) |
| 166 | |
| 167 | // rep 0 |
| 168 | seq.offset = 1 |
| 169 | if debugSequences { |
| 170 | println("repeat sequence", seq, "next s:", s) |
| 171 | } |
| 172 | blk.sequences = append(blk.sequences, seq) |
| 173 | s += lenght + repOff |
| 174 | nextEmit = s |
| 175 | if s >= sLimit { |
| 176 | if debugEncoder { |
| 177 | println("repeat ended", s, lenght) |
| 178 | |
| 179 | } |
| 180 | break encodeLoop |
| 181 | } |
| 182 | cv = load6432(src, s) |
| 183 | continue |
| 184 | } |
| 185 | } |
| 186 | // Find the offsets of our two matches. |
| 187 | coffsetL := s - (candidateL.offset - e.cur) |
| 188 | coffsetS := s - (candidateS.offset - e.cur) |
| 189 | |
| 190 | // Check if we have a long match. |
| 191 | if coffsetL < e.maxMatchOff && uint32(cv) == candidateL.val { |
| 192 | // Found a long match, likely at least 8 bytes. |
| 193 | // Reference encoder checks all 8 bytes, we only check 4, |
| 194 | // but the likelihood of both the first 4 bytes and the hash matching should be enough. |
| 195 | t = candidateL.offset - e.cur |
| 196 | if debugAsserts && s <= t { |
| 197 | panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) |
| 198 | } |
| 199 | if debugAsserts && s-t > e.maxMatchOff { |
| 200 | panic("s - t >e.maxMatchOff") |
| 201 | } |
| 202 | if debugMatches { |
| 203 | println("long match") |
| 204 | } |
| 205 | break |
| 206 | } |
| 207 | |
| 208 | // Check if we have a short match. |
| 209 | if coffsetS < e.maxMatchOff && uint32(cv) == candidateS.val { |
| 210 | // found a regular match |
| 211 | // See if we can find a long match at s+1 |
| 212 | const checkAt = 1 |
| 213 | cv := load6432(src, s+checkAt) |
| 214 | nextHashL = hashLen(cv, dFastLongTableBits, dFastLongLen) |
| 215 | candidateL = e.longTable[nextHashL] |
| 216 | coffsetL = s - (candidateL.offset - e.cur) + checkAt |
| 217 | |
| 218 | // We can store it, since we have at least a 4 byte match. |
| 219 | e.longTable[nextHashL] = tableEntry{offset: s + checkAt + e.cur, val: uint32(cv)} |
| 220 | if coffsetL < e.maxMatchOff && uint32(cv) == candidateL.val { |
| 221 | // Found a long match, likely at least 8 bytes. |
| 222 | // Reference encoder checks all 8 bytes, we only check 4, |
| 223 | // but the likelihood of both the first 4 bytes and the hash matching should be enough. |
| 224 | t = candidateL.offset - e.cur |
| 225 | s += checkAt |
| 226 | if debugMatches { |
| 227 | println("long match (after short)") |
| 228 | } |
| 229 | break |
| 230 | } |
| 231 | |
| 232 | t = candidateS.offset - e.cur |
| 233 | if debugAsserts && s <= t { |
| 234 | panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) |
| 235 | } |
| 236 | if debugAsserts && s-t > e.maxMatchOff { |
| 237 | panic("s - t >e.maxMatchOff") |
| 238 | } |
| 239 | if debugAsserts && t < 0 { |
| 240 | panic("t<0") |
| 241 | } |
| 242 | if debugMatches { |
| 243 | println("short match") |
| 244 | } |
| 245 | break |
| 246 | } |
| 247 | |
| 248 | // No match found, move forward in input. |
| 249 | s += stepSize + ((s - nextEmit) >> (kSearchStrength - 1)) |
| 250 | if s >= sLimit { |
| 251 | break encodeLoop |
| 252 | } |
| 253 | cv = load6432(src, s) |
| 254 | } |
| 255 | |
| 256 | // A 4-byte match has been found. Update recent offsets. |
| 257 | // We'll later see if more than 4 bytes. |
| 258 | offset2 = offset1 |
| 259 | offset1 = s - t |
| 260 | |
| 261 | if debugAsserts && s <= t { |
| 262 | panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) |
| 263 | } |
| 264 | |
| 265 | if debugAsserts && canRepeat && int(offset1) > len(src) { |
| 266 | panic("invalid offset") |
| 267 | } |
| 268 | |
| 269 | // Extend the 4-byte match as long as possible. |
| 270 | l := e.matchlen(s+4, t+4, src) + 4 |
| 271 | |
| 272 | // Extend backwards |
| 273 | tMin := s - e.maxMatchOff |
| 274 | if tMin < 0 { |
| 275 | tMin = 0 |
| 276 | } |
| 277 | for t > tMin && s > nextEmit && src[t-1] == src[s-1] && l < maxMatchLength { |
| 278 | s-- |
| 279 | t-- |
| 280 | l++ |
| 281 | } |
| 282 | |
| 283 | // Write our sequence |
| 284 | var seq seq |
| 285 | seq.litLen = uint32(s - nextEmit) |
| 286 | seq.matchLen = uint32(l - zstdMinMatch) |
| 287 | if seq.litLen > 0 { |
| 288 | blk.literals = append(blk.literals, src[nextEmit:s]...) |
| 289 | } |
| 290 | seq.offset = uint32(s-t) + 3 |
| 291 | s += l |
| 292 | if debugSequences { |
| 293 | println("sequence", seq, "next s:", s) |
| 294 | } |
| 295 | blk.sequences = append(blk.sequences, seq) |
| 296 | nextEmit = s |
| 297 | if s >= sLimit { |
| 298 | break encodeLoop |
| 299 | } |
| 300 | |
| 301 | // Index match start+1 (long) and start+2 (short) |
| 302 | index0 := s - l + 1 |
| 303 | // Index match end-2 (long) and end-1 (short) |
| 304 | index1 := s - 2 |
| 305 | |
| 306 | cv0 := load6432(src, index0) |
| 307 | cv1 := load6432(src, index1) |
| 308 | te0 := tableEntry{offset: index0 + e.cur, val: uint32(cv0)} |
| 309 | te1 := tableEntry{offset: index1 + e.cur, val: uint32(cv1)} |
| 310 | e.longTable[hashLen(cv0, dFastLongTableBits, dFastLongLen)] = te0 |
| 311 | e.longTable[hashLen(cv1, dFastLongTableBits, dFastLongLen)] = te1 |
| 312 | cv0 >>= 8 |
| 313 | cv1 >>= 8 |
| 314 | te0.offset++ |
| 315 | te1.offset++ |
| 316 | te0.val = uint32(cv0) |
| 317 | te1.val = uint32(cv1) |
| 318 | e.table[hashLen(cv0, dFastShortTableBits, dFastShortLen)] = te0 |
| 319 | e.table[hashLen(cv1, dFastShortTableBits, dFastShortLen)] = te1 |
| 320 | |
| 321 | cv = load6432(src, s) |
| 322 | |
| 323 | if !canRepeat { |
| 324 | continue |
| 325 | } |
| 326 | |
| 327 | // Check offset 2 |
| 328 | for { |
| 329 | o2 := s - offset2 |
| 330 | if load3232(src, o2) != uint32(cv) { |
| 331 | // Do regular search |
| 332 | break |
| 333 | } |
| 334 | |
| 335 | // Store this, since we have it. |
| 336 | nextHashS := hashLen(cv, dFastShortTableBits, dFastShortLen) |
| 337 | nextHashL := hashLen(cv, dFastLongTableBits, dFastLongLen) |
| 338 | |
| 339 | // We have at least 4 byte match. |
| 340 | // No need to check backwards. We come straight from a match |
| 341 | l := 4 + e.matchlen(s+4, o2+4, src) |
| 342 | |
| 343 | entry := tableEntry{offset: s + e.cur, val: uint32(cv)} |
| 344 | e.longTable[nextHashL] = entry |
| 345 | e.table[nextHashS] = entry |
| 346 | seq.matchLen = uint32(l) - zstdMinMatch |
| 347 | seq.litLen = 0 |
| 348 | |
| 349 | // Since litlen is always 0, this is offset 1. |
| 350 | seq.offset = 1 |
| 351 | s += l |
| 352 | nextEmit = s |
| 353 | if debugSequences { |
| 354 | println("sequence", seq, "next s:", s) |
| 355 | } |
| 356 | blk.sequences = append(blk.sequences, seq) |
| 357 | |
| 358 | // Swap offset 1 and 2. |
| 359 | offset1, offset2 = offset2, offset1 |
| 360 | if s >= sLimit { |
| 361 | // Finished |
| 362 | break encodeLoop |
| 363 | } |
| 364 | cv = load6432(src, s) |
| 365 | } |
| 366 | } |
| 367 | |
| 368 | if int(nextEmit) < len(src) { |
| 369 | blk.literals = append(blk.literals, src[nextEmit:]...) |
| 370 | blk.extraLits = len(src) - int(nextEmit) |
| 371 | } |
| 372 | blk.recentOffsets[0] = uint32(offset1) |
| 373 | blk.recentOffsets[1] = uint32(offset2) |
| 374 | if debugEncoder { |
| 375 | println("returning, recent offsets:", blk.recentOffsets, "extra literals:", blk.extraLits) |
| 376 | } |
| 377 | } |
| 378 | |
| 379 | // EncodeNoHist will encode a block with no history and no following blocks. |
| 380 | // Most notable difference is that src will not be copied for history and |
| 381 | // we do not need to check for max match length. |
| 382 | func (e *doubleFastEncoder) EncodeNoHist(blk *blockEnc, src []byte) { |
| 383 | const ( |
| 384 | // Input margin is the number of bytes we read (8) |
| 385 | // and the maximum we will read ahead (2) |
| 386 | inputMargin = 8 + 2 |
| 387 | minNonLiteralBlockSize = 16 |
| 388 | ) |
| 389 | |
| 390 | // Protect against e.cur wraparound. |
| 391 | if e.cur >= bufferReset { |
| 392 | for i := range e.table[:] { |
| 393 | e.table[i] = tableEntry{} |
| 394 | } |
| 395 | for i := range e.longTable[:] { |
| 396 | e.longTable[i] = tableEntry{} |
| 397 | } |
| 398 | e.cur = e.maxMatchOff |
| 399 | } |
| 400 | |
| 401 | s := int32(0) |
| 402 | blk.size = len(src) |
| 403 | if len(src) < minNonLiteralBlockSize { |
| 404 | blk.extraLits = len(src) |
| 405 | blk.literals = blk.literals[:len(src)] |
| 406 | copy(blk.literals, src) |
| 407 | return |
| 408 | } |
| 409 | |
| 410 | // Override src |
| 411 | sLimit := int32(len(src)) - inputMargin |
| 412 | // stepSize is the number of bytes to skip on every main loop iteration. |
| 413 | // It should be >= 1. |
| 414 | const stepSize = 1 |
| 415 | |
| 416 | const kSearchStrength = 8 |
| 417 | |
| 418 | // nextEmit is where in src the next emitLiteral should start from. |
| 419 | nextEmit := s |
| 420 | cv := load6432(src, s) |
| 421 | |
| 422 | // Relative offsets |
| 423 | offset1 := int32(blk.recentOffsets[0]) |
| 424 | offset2 := int32(blk.recentOffsets[1]) |
| 425 | |
| 426 | addLiterals := func(s *seq, until int32) { |
| 427 | if until == nextEmit { |
| 428 | return |
| 429 | } |
| 430 | blk.literals = append(blk.literals, src[nextEmit:until]...) |
| 431 | s.litLen = uint32(until - nextEmit) |
| 432 | } |
| 433 | if debugEncoder { |
| 434 | println("recent offsets:", blk.recentOffsets) |
| 435 | } |
| 436 | |
| 437 | encodeLoop: |
| 438 | for { |
| 439 | var t int32 |
| 440 | for { |
| 441 | |
| 442 | nextHashS := hashLen(cv, dFastShortTableBits, dFastShortLen) |
| 443 | nextHashL := hashLen(cv, dFastLongTableBits, dFastLongLen) |
| 444 | candidateL := e.longTable[nextHashL] |
| 445 | candidateS := e.table[nextHashS] |
| 446 | |
| 447 | const repOff = 1 |
| 448 | repIndex := s - offset1 + repOff |
| 449 | entry := tableEntry{offset: s + e.cur, val: uint32(cv)} |
| 450 | e.longTable[nextHashL] = entry |
| 451 | e.table[nextHashS] = entry |
| 452 | |
| 453 | if len(blk.sequences) > 2 { |
| 454 | if load3232(src, repIndex) == uint32(cv>>(repOff*8)) { |
| 455 | // Consider history as well. |
| 456 | var seq seq |
| 457 | //length := 4 + e.matchlen(s+4+repOff, repIndex+4, src) |
| 458 | length := 4 + int32(matchLen(src[s+4+repOff:], src[repIndex+4:])) |
| 459 | |
| 460 | seq.matchLen = uint32(length - zstdMinMatch) |
| 461 | |
| 462 | // We might be able to match backwards. |
| 463 | // Extend as long as we can. |
| 464 | start := s + repOff |
| 465 | // We end the search early, so we don't risk 0 literals |
| 466 | // and have to do special offset treatment. |
| 467 | startLimit := nextEmit + 1 |
| 468 | |
| 469 | tMin := s - e.maxMatchOff |
| 470 | if tMin < 0 { |
| 471 | tMin = 0 |
| 472 | } |
| 473 | for repIndex > tMin && start > startLimit && src[repIndex-1] == src[start-1] { |
| 474 | repIndex-- |
| 475 | start-- |
| 476 | seq.matchLen++ |
| 477 | } |
| 478 | addLiterals(&seq, start) |
| 479 | |
| 480 | // rep 0 |
| 481 | seq.offset = 1 |
| 482 | if debugSequences { |
| 483 | println("repeat sequence", seq, "next s:", s) |
| 484 | } |
| 485 | blk.sequences = append(blk.sequences, seq) |
| 486 | s += length + repOff |
| 487 | nextEmit = s |
| 488 | if s >= sLimit { |
| 489 | if debugEncoder { |
| 490 | println("repeat ended", s, length) |
| 491 | |
| 492 | } |
| 493 | break encodeLoop |
| 494 | } |
| 495 | cv = load6432(src, s) |
| 496 | continue |
| 497 | } |
| 498 | } |
| 499 | // Find the offsets of our two matches. |
| 500 | coffsetL := s - (candidateL.offset - e.cur) |
| 501 | coffsetS := s - (candidateS.offset - e.cur) |
| 502 | |
| 503 | // Check if we have a long match. |
| 504 | if coffsetL < e.maxMatchOff && uint32(cv) == candidateL.val { |
| 505 | // Found a long match, likely at least 8 bytes. |
| 506 | // Reference encoder checks all 8 bytes, we only check 4, |
| 507 | // but the likelihood of both the first 4 bytes and the hash matching should be enough. |
| 508 | t = candidateL.offset - e.cur |
| 509 | if debugAsserts && s <= t { |
| 510 | panic(fmt.Sprintf("s (%d) <= t (%d). cur: %d", s, t, e.cur)) |
| 511 | } |
| 512 | if debugAsserts && s-t > e.maxMatchOff { |
| 513 | panic("s - t >e.maxMatchOff") |
| 514 | } |
| 515 | if debugMatches { |
| 516 | println("long match") |
| 517 | } |
| 518 | break |
| 519 | } |
| 520 | |
| 521 | // Check if we have a short match. |
| 522 | if coffsetS < e.maxMatchOff && uint32(cv) == candidateS.val { |
| 523 | // found a regular match |
| 524 | // See if we can find a long match at s+1 |
| 525 | const checkAt = 1 |
| 526 | cv := load6432(src, s+checkAt) |
| 527 | nextHashL = hashLen(cv, dFastLongTableBits, dFastLongLen) |
| 528 | candidateL = e.longTable[nextHashL] |
| 529 | coffsetL = s - (candidateL.offset - e.cur) + checkAt |
| 530 | |
| 531 | // We can store it, since we have at least a 4 byte match. |
| 532 | e.longTable[nextHashL] = tableEntry{offset: s + checkAt + e.cur, val: uint32(cv)} |
| 533 | if coffsetL < e.maxMatchOff && uint32(cv) == candidateL.val { |
| 534 | // Found a long match, likely at least 8 bytes. |
| 535 | // Reference encoder checks all 8 bytes, we only check 4, |
| 536 | // but the likelihood of both the first 4 bytes and the hash matching should be enough. |
| 537 | t = candidateL.offset - e.cur |
| 538 | s += checkAt |
| 539 | if debugMatches { |
| 540 | println("long match (after short)") |
| 541 | } |
| 542 | break |
| 543 | } |
| 544 | |
| 545 | t = candidateS.offset - e.cur |
| 546 | if debugAsserts && s <= t { |
| 547 | panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) |
| 548 | } |
| 549 | if debugAsserts && s-t > e.maxMatchOff { |
| 550 | panic("s - t >e.maxMatchOff") |
| 551 | } |
| 552 | if debugAsserts && t < 0 { |
| 553 | panic("t<0") |
| 554 | } |
| 555 | if debugMatches { |
| 556 | println("short match") |
| 557 | } |
| 558 | break |
| 559 | } |
| 560 | |
| 561 | // No match found, move forward in input. |
| 562 | s += stepSize + ((s - nextEmit) >> (kSearchStrength - 1)) |
| 563 | if s >= sLimit { |
| 564 | break encodeLoop |
| 565 | } |
| 566 | cv = load6432(src, s) |
| 567 | } |
| 568 | |
| 569 | // A 4-byte match has been found. Update recent offsets. |
| 570 | // We'll later see if more than 4 bytes. |
| 571 | offset2 = offset1 |
| 572 | offset1 = s - t |
| 573 | |
| 574 | if debugAsserts && s <= t { |
| 575 | panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) |
| 576 | } |
| 577 | |
| 578 | // Extend the 4-byte match as long as possible. |
| 579 | //l := e.matchlen(s+4, t+4, src) + 4 |
| 580 | l := int32(matchLen(src[s+4:], src[t+4:])) + 4 |
| 581 | |
| 582 | // Extend backwards |
| 583 | tMin := s - e.maxMatchOff |
| 584 | if tMin < 0 { |
| 585 | tMin = 0 |
| 586 | } |
| 587 | for t > tMin && s > nextEmit && src[t-1] == src[s-1] { |
| 588 | s-- |
| 589 | t-- |
| 590 | l++ |
| 591 | } |
| 592 | |
| 593 | // Write our sequence |
| 594 | var seq seq |
| 595 | seq.litLen = uint32(s - nextEmit) |
| 596 | seq.matchLen = uint32(l - zstdMinMatch) |
| 597 | if seq.litLen > 0 { |
| 598 | blk.literals = append(blk.literals, src[nextEmit:s]...) |
| 599 | } |
| 600 | seq.offset = uint32(s-t) + 3 |
| 601 | s += l |
| 602 | if debugSequences { |
| 603 | println("sequence", seq, "next s:", s) |
| 604 | } |
| 605 | blk.sequences = append(blk.sequences, seq) |
| 606 | nextEmit = s |
| 607 | if s >= sLimit { |
| 608 | break encodeLoop |
| 609 | } |
| 610 | |
| 611 | // Index match start+1 (long) and start+2 (short) |
| 612 | index0 := s - l + 1 |
| 613 | // Index match end-2 (long) and end-1 (short) |
| 614 | index1 := s - 2 |
| 615 | |
| 616 | cv0 := load6432(src, index0) |
| 617 | cv1 := load6432(src, index1) |
| 618 | te0 := tableEntry{offset: index0 + e.cur, val: uint32(cv0)} |
| 619 | te1 := tableEntry{offset: index1 + e.cur, val: uint32(cv1)} |
| 620 | e.longTable[hashLen(cv0, dFastLongTableBits, dFastLongLen)] = te0 |
| 621 | e.longTable[hashLen(cv1, dFastLongTableBits, dFastLongLen)] = te1 |
| 622 | cv0 >>= 8 |
| 623 | cv1 >>= 8 |
| 624 | te0.offset++ |
| 625 | te1.offset++ |
| 626 | te0.val = uint32(cv0) |
| 627 | te1.val = uint32(cv1) |
| 628 | e.table[hashLen(cv0, dFastShortTableBits, dFastShortLen)] = te0 |
| 629 | e.table[hashLen(cv1, dFastShortTableBits, dFastShortLen)] = te1 |
| 630 | |
| 631 | cv = load6432(src, s) |
| 632 | |
| 633 | if len(blk.sequences) <= 2 { |
| 634 | continue |
| 635 | } |
| 636 | |
| 637 | // Check offset 2 |
| 638 | for { |
| 639 | o2 := s - offset2 |
| 640 | if load3232(src, o2) != uint32(cv) { |
| 641 | // Do regular search |
| 642 | break |
| 643 | } |
| 644 | |
| 645 | // Store this, since we have it. |
| 646 | nextHashS := hashLen(cv1>>8, dFastShortTableBits, dFastShortLen) |
| 647 | nextHashL := hashLen(cv, dFastLongTableBits, dFastLongLen) |
| 648 | |
| 649 | // We have at least 4 byte match. |
| 650 | // No need to check backwards. We come straight from a match |
| 651 | //l := 4 + e.matchlen(s+4, o2+4, src) |
| 652 | l := 4 + int32(matchLen(src[s+4:], src[o2+4:])) |
| 653 | |
| 654 | entry := tableEntry{offset: s + e.cur, val: uint32(cv)} |
| 655 | e.longTable[nextHashL] = entry |
| 656 | e.table[nextHashS] = entry |
| 657 | seq.matchLen = uint32(l) - zstdMinMatch |
| 658 | seq.litLen = 0 |
| 659 | |
| 660 | // Since litlen is always 0, this is offset 1. |
| 661 | seq.offset = 1 |
| 662 | s += l |
| 663 | nextEmit = s |
| 664 | if debugSequences { |
| 665 | println("sequence", seq, "next s:", s) |
| 666 | } |
| 667 | blk.sequences = append(blk.sequences, seq) |
| 668 | |
| 669 | // Swap offset 1 and 2. |
| 670 | offset1, offset2 = offset2, offset1 |
| 671 | if s >= sLimit { |
| 672 | // Finished |
| 673 | break encodeLoop |
| 674 | } |
| 675 | cv = load6432(src, s) |
| 676 | } |
| 677 | } |
| 678 | |
| 679 | if int(nextEmit) < len(src) { |
| 680 | blk.literals = append(blk.literals, src[nextEmit:]...) |
| 681 | blk.extraLits = len(src) - int(nextEmit) |
| 682 | } |
| 683 | if debugEncoder { |
| 684 | println("returning, recent offsets:", blk.recentOffsets, "extra literals:", blk.extraLits) |
| 685 | } |
| 686 | |
| 687 | // We do not store history, so we must offset e.cur to avoid false matches for next user. |
| 688 | if e.cur < bufferReset { |
| 689 | e.cur += int32(len(src)) |
| 690 | } |
| 691 | } |
| 692 | |
| 693 | // Encode will encode the content, with a dictionary if initialized for it. |
| 694 | func (e *doubleFastEncoderDict) Encode(blk *blockEnc, src []byte) { |
| 695 | const ( |
| 696 | // Input margin is the number of bytes we read (8) |
| 697 | // and the maximum we will read ahead (2) |
| 698 | inputMargin = 8 + 2 |
| 699 | minNonLiteralBlockSize = 16 |
| 700 | ) |
| 701 | |
| 702 | // Protect against e.cur wraparound. |
| 703 | for e.cur >= bufferReset { |
| 704 | if len(e.hist) == 0 { |
| 705 | for i := range e.table[:] { |
| 706 | e.table[i] = tableEntry{} |
| 707 | } |
| 708 | for i := range e.longTable[:] { |
| 709 | e.longTable[i] = tableEntry{} |
| 710 | } |
| 711 | e.markAllShardsDirty() |
| 712 | e.cur = e.maxMatchOff |
| 713 | break |
| 714 | } |
| 715 | // Shift down everything in the table that isn't already too far away. |
| 716 | minOff := e.cur + int32(len(e.hist)) - e.maxMatchOff |
| 717 | for i := range e.table[:] { |
| 718 | v := e.table[i].offset |
| 719 | if v < minOff { |
| 720 | v = 0 |
| 721 | } else { |
| 722 | v = v - e.cur + e.maxMatchOff |
| 723 | } |
| 724 | e.table[i].offset = v |
| 725 | } |
| 726 | for i := range e.longTable[:] { |
| 727 | v := e.longTable[i].offset |
| 728 | if v < minOff { |
| 729 | v = 0 |
| 730 | } else { |
| 731 | v = v - e.cur + e.maxMatchOff |
| 732 | } |
| 733 | e.longTable[i].offset = v |
| 734 | } |
| 735 | e.markAllShardsDirty() |
| 736 | e.cur = e.maxMatchOff |
| 737 | break |
| 738 | } |
| 739 | |
| 740 | s := e.addBlock(src) |
| 741 | blk.size = len(src) |
| 742 | if len(src) < minNonLiteralBlockSize { |
| 743 | blk.extraLits = len(src) |
| 744 | blk.literals = blk.literals[:len(src)] |
| 745 | copy(blk.literals, src) |
| 746 | return |
| 747 | } |
| 748 | |
| 749 | // Override src |
| 750 | src = e.hist |
| 751 | sLimit := int32(len(src)) - inputMargin |
| 752 | // stepSize is the number of bytes to skip on every main loop iteration. |
| 753 | // It should be >= 1. |
| 754 | const stepSize = 1 |
| 755 | |
| 756 | const kSearchStrength = 8 |
| 757 | |
| 758 | // nextEmit is where in src the next emitLiteral should start from. |
| 759 | nextEmit := s |
| 760 | cv := load6432(src, s) |
| 761 | |
| 762 | // Relative offsets |
| 763 | offset1 := int32(blk.recentOffsets[0]) |
| 764 | offset2 := int32(blk.recentOffsets[1]) |
| 765 | |
| 766 | addLiterals := func(s *seq, until int32) { |
| 767 | if until == nextEmit { |
| 768 | return |
| 769 | } |
| 770 | blk.literals = append(blk.literals, src[nextEmit:until]...) |
| 771 | s.litLen = uint32(until - nextEmit) |
| 772 | } |
| 773 | if debugEncoder { |
| 774 | println("recent offsets:", blk.recentOffsets) |
| 775 | } |
| 776 | |
| 777 | encodeLoop: |
| 778 | for { |
| 779 | var t int32 |
| 780 | // We allow the encoder to optionally turn off repeat offsets across blocks |
| 781 | canRepeat := len(blk.sequences) > 2 |
| 782 | |
| 783 | for { |
| 784 | if debugAsserts && canRepeat && offset1 == 0 { |
| 785 | panic("offset0 was 0") |
| 786 | } |
| 787 | |
| 788 | nextHashS := hashLen(cv, dFastShortTableBits, dFastShortLen) |
| 789 | nextHashL := hashLen(cv, dFastLongTableBits, dFastLongLen) |
| 790 | candidateL := e.longTable[nextHashL] |
| 791 | candidateS := e.table[nextHashS] |
| 792 | |
| 793 | const repOff = 1 |
| 794 | repIndex := s - offset1 + repOff |
| 795 | entry := tableEntry{offset: s + e.cur, val: uint32(cv)} |
| 796 | e.longTable[nextHashL] = entry |
| 797 | e.markLongShardDirty(nextHashL) |
| 798 | e.table[nextHashS] = entry |
| 799 | e.markShardDirty(nextHashS) |
| 800 | |
| 801 | if canRepeat { |
| 802 | if repIndex >= 0 && load3232(src, repIndex) == uint32(cv>>(repOff*8)) { |
| 803 | // Consider history as well. |
| 804 | var seq seq |
| 805 | lenght := 4 + e.matchlen(s+4+repOff, repIndex+4, src) |
| 806 | |
| 807 | seq.matchLen = uint32(lenght - zstdMinMatch) |
| 808 | |
| 809 | // We might be able to match backwards. |
| 810 | // Extend as long as we can. |
| 811 | start := s + repOff |
| 812 | // We end the search early, so we don't risk 0 literals |
| 813 | // and have to do special offset treatment. |
| 814 | startLimit := nextEmit + 1 |
| 815 | |
| 816 | tMin := s - e.maxMatchOff |
| 817 | if tMin < 0 { |
| 818 | tMin = 0 |
| 819 | } |
| 820 | for repIndex > tMin && start > startLimit && src[repIndex-1] == src[start-1] && seq.matchLen < maxMatchLength-zstdMinMatch-1 { |
| 821 | repIndex-- |
| 822 | start-- |
| 823 | seq.matchLen++ |
| 824 | } |
| 825 | addLiterals(&seq, start) |
| 826 | |
| 827 | // rep 0 |
| 828 | seq.offset = 1 |
| 829 | if debugSequences { |
| 830 | println("repeat sequence", seq, "next s:", s) |
| 831 | } |
| 832 | blk.sequences = append(blk.sequences, seq) |
| 833 | s += lenght + repOff |
| 834 | nextEmit = s |
| 835 | if s >= sLimit { |
| 836 | if debugEncoder { |
| 837 | println("repeat ended", s, lenght) |
| 838 | |
| 839 | } |
| 840 | break encodeLoop |
| 841 | } |
| 842 | cv = load6432(src, s) |
| 843 | continue |
| 844 | } |
| 845 | } |
| 846 | // Find the offsets of our two matches. |
| 847 | coffsetL := s - (candidateL.offset - e.cur) |
| 848 | coffsetS := s - (candidateS.offset - e.cur) |
| 849 | |
| 850 | // Check if we have a long match. |
| 851 | if coffsetL < e.maxMatchOff && uint32(cv) == candidateL.val { |
| 852 | // Found a long match, likely at least 8 bytes. |
| 853 | // Reference encoder checks all 8 bytes, we only check 4, |
| 854 | // but the likelihood of both the first 4 bytes and the hash matching should be enough. |
| 855 | t = candidateL.offset - e.cur |
| 856 | if debugAsserts && s <= t { |
| 857 | panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) |
| 858 | } |
| 859 | if debugAsserts && s-t > e.maxMatchOff { |
| 860 | panic("s - t >e.maxMatchOff") |
| 861 | } |
| 862 | if debugMatches { |
| 863 | println("long match") |
| 864 | } |
| 865 | break |
| 866 | } |
| 867 | |
| 868 | // Check if we have a short match. |
| 869 | if coffsetS < e.maxMatchOff && uint32(cv) == candidateS.val { |
| 870 | // found a regular match |
| 871 | // See if we can find a long match at s+1 |
| 872 | const checkAt = 1 |
| 873 | cv := load6432(src, s+checkAt) |
| 874 | nextHashL = hashLen(cv, dFastLongTableBits, dFastLongLen) |
| 875 | candidateL = e.longTable[nextHashL] |
| 876 | coffsetL = s - (candidateL.offset - e.cur) + checkAt |
| 877 | |
| 878 | // We can store it, since we have at least a 4 byte match. |
| 879 | e.longTable[nextHashL] = tableEntry{offset: s + checkAt + e.cur, val: uint32(cv)} |
| 880 | e.markLongShardDirty(nextHashL) |
| 881 | if coffsetL < e.maxMatchOff && uint32(cv) == candidateL.val { |
| 882 | // Found a long match, likely at least 8 bytes. |
| 883 | // Reference encoder checks all 8 bytes, we only check 4, |
| 884 | // but the likelihood of both the first 4 bytes and the hash matching should be enough. |
| 885 | t = candidateL.offset - e.cur |
| 886 | s += checkAt |
| 887 | if debugMatches { |
| 888 | println("long match (after short)") |
| 889 | } |
| 890 | break |
| 891 | } |
| 892 | |
| 893 | t = candidateS.offset - e.cur |
| 894 | if debugAsserts && s <= t { |
| 895 | panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) |
| 896 | } |
| 897 | if debugAsserts && s-t > e.maxMatchOff { |
| 898 | panic("s - t >e.maxMatchOff") |
| 899 | } |
| 900 | if debugAsserts && t < 0 { |
| 901 | panic("t<0") |
| 902 | } |
| 903 | if debugMatches { |
| 904 | println("short match") |
| 905 | } |
| 906 | break |
| 907 | } |
| 908 | |
| 909 | // No match found, move forward in input. |
| 910 | s += stepSize + ((s - nextEmit) >> (kSearchStrength - 1)) |
| 911 | if s >= sLimit { |
| 912 | break encodeLoop |
| 913 | } |
| 914 | cv = load6432(src, s) |
| 915 | } |
| 916 | |
| 917 | // A 4-byte match has been found. Update recent offsets. |
| 918 | // We'll later see if more than 4 bytes. |
| 919 | offset2 = offset1 |
| 920 | offset1 = s - t |
| 921 | |
| 922 | if debugAsserts && s <= t { |
| 923 | panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) |
| 924 | } |
| 925 | |
| 926 | if debugAsserts && canRepeat && int(offset1) > len(src) { |
| 927 | panic("invalid offset") |
| 928 | } |
| 929 | |
| 930 | // Extend the 4-byte match as long as possible. |
| 931 | l := e.matchlen(s+4, t+4, src) + 4 |
| 932 | |
| 933 | // Extend backwards |
| 934 | tMin := s - e.maxMatchOff |
| 935 | if tMin < 0 { |
| 936 | tMin = 0 |
| 937 | } |
| 938 | for t > tMin && s > nextEmit && src[t-1] == src[s-1] && l < maxMatchLength { |
| 939 | s-- |
| 940 | t-- |
| 941 | l++ |
| 942 | } |
| 943 | |
| 944 | // Write our sequence |
| 945 | var seq seq |
| 946 | seq.litLen = uint32(s - nextEmit) |
| 947 | seq.matchLen = uint32(l - zstdMinMatch) |
| 948 | if seq.litLen > 0 { |
| 949 | blk.literals = append(blk.literals, src[nextEmit:s]...) |
| 950 | } |
| 951 | seq.offset = uint32(s-t) + 3 |
| 952 | s += l |
| 953 | if debugSequences { |
| 954 | println("sequence", seq, "next s:", s) |
| 955 | } |
| 956 | blk.sequences = append(blk.sequences, seq) |
| 957 | nextEmit = s |
| 958 | if s >= sLimit { |
| 959 | break encodeLoop |
| 960 | } |
| 961 | |
| 962 | // Index match start+1 (long) and start+2 (short) |
| 963 | index0 := s - l + 1 |
| 964 | // Index match end-2 (long) and end-1 (short) |
| 965 | index1 := s - 2 |
| 966 | |
| 967 | cv0 := load6432(src, index0) |
| 968 | cv1 := load6432(src, index1) |
| 969 | te0 := tableEntry{offset: index0 + e.cur, val: uint32(cv0)} |
| 970 | te1 := tableEntry{offset: index1 + e.cur, val: uint32(cv1)} |
| 971 | longHash1 := hashLen(cv0, dFastLongTableBits, dFastLongLen) |
| 972 | longHash2 := hashLen(cv0, dFastLongTableBits, dFastLongLen) |
| 973 | e.longTable[longHash1] = te0 |
| 974 | e.longTable[longHash2] = te1 |
| 975 | e.markLongShardDirty(longHash1) |
| 976 | e.markLongShardDirty(longHash2) |
| 977 | cv0 >>= 8 |
| 978 | cv1 >>= 8 |
| 979 | te0.offset++ |
| 980 | te1.offset++ |
| 981 | te0.val = uint32(cv0) |
| 982 | te1.val = uint32(cv1) |
| 983 | hashVal1 := hashLen(cv0, dFastShortTableBits, dFastShortLen) |
| 984 | hashVal2 := hashLen(cv1, dFastShortTableBits, dFastShortLen) |
| 985 | e.table[hashVal1] = te0 |
| 986 | e.markShardDirty(hashVal1) |
| 987 | e.table[hashVal2] = te1 |
| 988 | e.markShardDirty(hashVal2) |
| 989 | |
| 990 | cv = load6432(src, s) |
| 991 | |
| 992 | if !canRepeat { |
| 993 | continue |
| 994 | } |
| 995 | |
| 996 | // Check offset 2 |
| 997 | for { |
| 998 | o2 := s - offset2 |
| 999 | if load3232(src, o2) != uint32(cv) { |
| 1000 | // Do regular search |
| 1001 | break |
| 1002 | } |
| 1003 | |
| 1004 | // Store this, since we have it. |
| 1005 | nextHashS := hashLen(cv, dFastShortTableBits, dFastShortLen) |
| 1006 | nextHashL := hashLen(cv, dFastLongTableBits, dFastLongLen) |
| 1007 | |
| 1008 | // We have at least 4 byte match. |
| 1009 | // No need to check backwards. We come straight from a match |
| 1010 | l := 4 + e.matchlen(s+4, o2+4, src) |
| 1011 | |
| 1012 | entry := tableEntry{offset: s + e.cur, val: uint32(cv)} |
| 1013 | e.longTable[nextHashL] = entry |
| 1014 | e.markLongShardDirty(nextHashL) |
| 1015 | e.table[nextHashS] = entry |
| 1016 | e.markShardDirty(nextHashS) |
| 1017 | seq.matchLen = uint32(l) - zstdMinMatch |
| 1018 | seq.litLen = 0 |
| 1019 | |
| 1020 | // Since litlen is always 0, this is offset 1. |
| 1021 | seq.offset = 1 |
| 1022 | s += l |
| 1023 | nextEmit = s |
| 1024 | if debugSequences { |
| 1025 | println("sequence", seq, "next s:", s) |
| 1026 | } |
| 1027 | blk.sequences = append(blk.sequences, seq) |
| 1028 | |
| 1029 | // Swap offset 1 and 2. |
| 1030 | offset1, offset2 = offset2, offset1 |
| 1031 | if s >= sLimit { |
| 1032 | // Finished |
| 1033 | break encodeLoop |
| 1034 | } |
| 1035 | cv = load6432(src, s) |
| 1036 | } |
| 1037 | } |
| 1038 | |
| 1039 | if int(nextEmit) < len(src) { |
| 1040 | blk.literals = append(blk.literals, src[nextEmit:]...) |
| 1041 | blk.extraLits = len(src) - int(nextEmit) |
| 1042 | } |
| 1043 | blk.recentOffsets[0] = uint32(offset1) |
| 1044 | blk.recentOffsets[1] = uint32(offset2) |
| 1045 | if debugEncoder { |
| 1046 | println("returning, recent offsets:", blk.recentOffsets, "extra literals:", blk.extraLits) |
| 1047 | } |
| 1048 | // If we encoded more than 64K mark all dirty. |
| 1049 | if len(src) > 64<<10 { |
| 1050 | e.markAllShardsDirty() |
| 1051 | } |
| 1052 | } |
| 1053 | |
| 1054 | // ResetDict will reset and set a dictionary if not nil |
| 1055 | func (e *doubleFastEncoder) Reset(d *dict, singleBlock bool) { |
| 1056 | e.fastEncoder.Reset(d, singleBlock) |
| 1057 | if d != nil { |
| 1058 | panic("doubleFastEncoder: Reset with dict not supported") |
| 1059 | } |
| 1060 | } |
| 1061 | |
| 1062 | // ResetDict will reset and set a dictionary if not nil |
| 1063 | func (e *doubleFastEncoderDict) Reset(d *dict, singleBlock bool) { |
| 1064 | allDirty := e.allDirty |
| 1065 | e.fastEncoderDict.Reset(d, singleBlock) |
| 1066 | if d == nil { |
| 1067 | return |
| 1068 | } |
| 1069 | |
| 1070 | // Init or copy dict table |
| 1071 | if len(e.dictLongTable) != len(e.longTable) || d.id != e.lastDictID { |
| 1072 | if len(e.dictLongTable) != len(e.longTable) { |
| 1073 | e.dictLongTable = make([]tableEntry, len(e.longTable)) |
| 1074 | } |
| 1075 | if len(d.content) >= 8 { |
| 1076 | cv := load6432(d.content, 0) |
| 1077 | e.dictLongTable[hashLen(cv, dFastLongTableBits, dFastLongLen)] = tableEntry{ |
| 1078 | val: uint32(cv), |
| 1079 | offset: e.maxMatchOff, |
| 1080 | } |
| 1081 | end := int32(len(d.content)) - 8 + e.maxMatchOff |
| 1082 | for i := e.maxMatchOff + 1; i < end; i++ { |
| 1083 | cv = cv>>8 | (uint64(d.content[i-e.maxMatchOff+7]) << 56) |
| 1084 | e.dictLongTable[hashLen(cv, dFastLongTableBits, dFastLongLen)] = tableEntry{ |
| 1085 | val: uint32(cv), |
| 1086 | offset: i, |
| 1087 | } |
| 1088 | } |
| 1089 | } |
| 1090 | e.lastDictID = d.id |
| 1091 | e.allDirty = true |
| 1092 | } |
| 1093 | // Reset table to initial state |
| 1094 | e.cur = e.maxMatchOff |
| 1095 | |
| 1096 | dirtyShardCnt := 0 |
| 1097 | if !allDirty { |
| 1098 | for i := range e.longTableShardDirty { |
| 1099 | if e.longTableShardDirty[i] { |
| 1100 | dirtyShardCnt++ |
| 1101 | } |
| 1102 | } |
| 1103 | } |
| 1104 | |
| 1105 | if allDirty || dirtyShardCnt > dLongTableShardCnt/2 { |
| 1106 | copy(e.longTable[:], e.dictLongTable) |
| 1107 | for i := range e.longTableShardDirty { |
| 1108 | e.longTableShardDirty[i] = false |
| 1109 | } |
| 1110 | return |
| 1111 | } |
| 1112 | for i := range e.longTableShardDirty { |
| 1113 | if !e.longTableShardDirty[i] { |
| 1114 | continue |
| 1115 | } |
| 1116 | |
| 1117 | copy(e.longTable[i*dLongTableShardSize:(i+1)*dLongTableShardSize], e.dictLongTable[i*dLongTableShardSize:(i+1)*dLongTableShardSize]) |
| 1118 | e.longTableShardDirty[i] = false |
| 1119 | } |
| 1120 | } |
| 1121 | |
| 1122 | func (e *doubleFastEncoderDict) markLongShardDirty(entryNum uint32) { |
| 1123 | e.longTableShardDirty[entryNum/dLongTableShardSize] = true |
| 1124 | } |