1 /* LzFind.c -- Match finder for LZ algorithms 2 2009-04-22 : Igor Pavlov : Public domain */ 3 4 #include "Precomp.h" 5 6 #include <string.h> 7 8 #include "LzFind.h" 9 #include "LzHash.h" 10 11 #define kEmptyHashValue 0 12 #define kMaxValForNormalize ((UInt32)0xFFFFFFFF) 13 #define kNormalizeStepMin (1 << 10) /* it must be power of 2 */ 14 #define kNormalizeMask (~(kNormalizeStepMin - 1)) 15 #define kMaxHistorySize ((UInt32)3 << 30) 16 17 #define kStartMaxLen 3 18 19 static void LzInWindow_Free(CMatchFinder *p, ISzAlloc *alloc) 20 { 21 if (!p->directInput) 22 { 23 alloc->Free(alloc, p->bufferBase); 24 p->bufferBase = 0; 25 } 26 } 27 28 /* keepSizeBefore + keepSizeAfter + keepSizeReserv must be < 4G) */ 29 30 static int LzInWindow_Create(CMatchFinder *p, UInt32 keepSizeReserv, ISzAlloc *alloc) 31 { 32 UInt32 blockSize = p->keepSizeBefore + p->keepSizeAfter + keepSizeReserv; 33 if (p->directInput) 34 { 35 p->blockSize = blockSize; 36 return 1; 37 } 38 if (p->bufferBase == 0 || p->blockSize != blockSize) 39 { 40 LzInWindow_Free(p, alloc); 41 p->blockSize = blockSize; 42 p->bufferBase = (Byte *)alloc->Alloc(alloc, (size_t)blockSize); 43 } 44 return (p->bufferBase != 0); 45 } 46 47 Byte *MatchFinder_GetPointerToCurrentPos(CMatchFinder *p) { return p->buffer; } 48 Byte MatchFinder_GetIndexByte(CMatchFinder *p, Int32 index) { return p->buffer[index]; } 49 50 UInt32 MatchFinder_GetNumAvailableBytes(CMatchFinder *p) { return p->streamPos - p->pos; } 51 52 void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue) 53 { 54 p->posLimit -= subValue; 55 p->pos -= subValue; 56 p->streamPos -= subValue; 57 } 58 59 static void MatchFinder_ReadBlock(CMatchFinder *p) 60 { 61 if (p->streamEndWasReached || p->result != SZ_OK) 62 return; 63 if (p->directInput) 64 { 65 UInt32 curSize = 0xFFFFFFFF - p->streamPos; 66 if (curSize > p->directInputRem) 67 curSize = (UInt32)p->directInputRem; 68 p->directInputRem -= curSize; 69 p->streamPos += curSize; 70 if (p->directInputRem == 0) 71 p->streamEndWasReached = 1; 72 return; 73 } 74 for (;;) 75 { 76 Byte *dest = p->buffer + (p->streamPos - p->pos); 77 size_t size = (p->bufferBase + p->blockSize - dest); 78 if (size == 0) 79 return; 80 p->result = p->stream->Read(p->stream, dest, &size); 81 if (p->result != SZ_OK) 82 return; 83 if (size == 0) 84 { 85 p->streamEndWasReached = 1; 86 return; 87 } 88 p->streamPos += (UInt32)size; 89 if (p->streamPos - p->pos > p->keepSizeAfter) 90 return; 91 } 92 } 93 94 void MatchFinder_MoveBlock(CMatchFinder *p) 95 { 96 memmove(p->bufferBase, 97 p->buffer - p->keepSizeBefore, 98 (size_t)(p->streamPos - p->pos + p->keepSizeBefore)); 99 p->buffer = p->bufferBase + p->keepSizeBefore; 100 } 101 102 int MatchFinder_NeedMove(CMatchFinder *p) 103 { 104 if (p->directInput) 105 return 0; 106 /* if (p->streamEndWasReached) return 0; */ 107 return ((size_t)(p->bufferBase + p->blockSize - p->buffer) <= p->keepSizeAfter); 108 } 109 110 void MatchFinder_ReadIfRequired(CMatchFinder *p) 111 { 112 if (p->streamEndWasReached) 113 return; 114 if (p->keepSizeAfter >= p->streamPos - p->pos) 115 MatchFinder_ReadBlock(p); 116 } 117 118 static void MatchFinder_CheckAndMoveAndRead(CMatchFinder *p) 119 { 120 if (MatchFinder_NeedMove(p)) 121 MatchFinder_MoveBlock(p); 122 MatchFinder_ReadBlock(p); 123 } 124 125 static void MatchFinder_SetDefaultSettings(CMatchFinder *p) 126 { 127 p->cutValue = 32; 128 p->btMode = 1; 129 p->numHashBytes = 4; 130 p->bigHash = 0; 131 } 132 133 #define kCrcPoly 0xEDB88320 134 135 void MatchFinder_Construct(CMatchFinder *p) 136 { 137 UInt32 i; 138 p->bufferBase = 0; 139 p->directInput = 0; 140 p->hash = 0; 141 MatchFinder_SetDefaultSettings(p); 142 143 for (i = 0; i < 256; i++) 144 { 145 UInt32 r = i; 146 int j; 147 for (j = 0; j < 8; j++) 148 r = (r >> 1) ^ (kCrcPoly & ~((r & 1) - 1)); 149 p->crc[i] = r; 150 } 151 } 152 153 static void MatchFinder_FreeThisClassMemory(CMatchFinder *p, ISzAlloc *alloc) 154 { 155 alloc->Free(alloc, p->hash); 156 p->hash = 0; 157 } 158 159 void MatchFinder_Free(CMatchFinder *p, ISzAlloc *alloc) 160 { 161 MatchFinder_FreeThisClassMemory(p, alloc); 162 LzInWindow_Free(p, alloc); 163 } 164 165 static CLzRef* AllocRefs(UInt32 num, ISzAlloc *alloc) 166 { 167 size_t sizeInBytes = (size_t)num * sizeof(CLzRef); 168 if (sizeInBytes / sizeof(CLzRef) != num) 169 return 0; 170 return (CLzRef *)alloc->Alloc(alloc, sizeInBytes); 171 } 172 173 int MatchFinder_Create(CMatchFinder *p, UInt32 historySize, 174 UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter, 175 ISzAlloc *alloc) 176 { 177 UInt32 sizeReserv; 178 if (historySize > kMaxHistorySize) 179 { 180 MatchFinder_Free(p, alloc); 181 return 0; 182 } 183 sizeReserv = historySize >> 1; 184 if (historySize > ((UInt32)2 << 30)) 185 sizeReserv = historySize >> 2; 186 sizeReserv += (keepAddBufferBefore + matchMaxLen + keepAddBufferAfter) / 2 + (1 << 19); 187 188 p->keepSizeBefore = historySize + keepAddBufferBefore + 1; 189 p->keepSizeAfter = matchMaxLen + keepAddBufferAfter; 190 /* we need one additional byte, since we use MoveBlock after pos++ and before dictionary using */ 191 if (LzInWindow_Create(p, sizeReserv, alloc)) 192 { 193 UInt32 newCyclicBufferSize = historySize + 1; 194 UInt32 hs; 195 p->matchMaxLen = matchMaxLen; 196 { 197 p->fixedHashSize = 0; 198 if (p->numHashBytes == 2) 199 hs = (1 << 16) - 1; 200 else 201 { 202 hs = historySize - 1; 203 hs |= (hs >> 1); 204 hs |= (hs >> 2); 205 hs |= (hs >> 4); 206 hs |= (hs >> 8); 207 hs >>= 1; 208 hs |= 0xFFFF; /* don't change it! It's required for Deflate */ 209 if (hs > (1 << 24)) 210 { 211 if (p->numHashBytes == 3) 212 hs = (1 << 24) - 1; 213 else 214 hs >>= 1; 215 } 216 } 217 p->hashMask = hs; 218 hs++; 219 if (p->numHashBytes > 2) p->fixedHashSize += kHash2Size; 220 if (p->numHashBytes > 3) p->fixedHashSize += kHash3Size; 221 if (p->numHashBytes > 4) p->fixedHashSize += kHash4Size; 222 hs += p->fixedHashSize; 223 } 224 225 { 226 UInt32 prevSize = p->hashSizeSum + p->numSons; 227 UInt32 newSize; 228 p->historySize = historySize; 229 p->hashSizeSum = hs; 230 p->cyclicBufferSize = newCyclicBufferSize; 231 p->numSons = (p->btMode ? newCyclicBufferSize * 2 : newCyclicBufferSize); 232 newSize = p->hashSizeSum + p->numSons; 233 if (p->hash != 0 && prevSize == newSize) 234 return 1; 235 MatchFinder_FreeThisClassMemory(p, alloc); 236 p->hash = AllocRefs(newSize, alloc); 237 if (p->hash != 0) 238 { 239 p->son = p->hash + p->hashSizeSum; 240 return 1; 241 } 242 } 243 } 244 MatchFinder_Free(p, alloc); 245 return 0; 246 } 247 248 static void MatchFinder_SetLimits(CMatchFinder *p) 249 { 250 UInt32 limit = kMaxValForNormalize - p->pos; 251 UInt32 limit2 = p->cyclicBufferSize - p->cyclicBufferPos; 252 if (limit2 < limit) 253 limit = limit2; 254 limit2 = p->streamPos - p->pos; 255 if (limit2 <= p->keepSizeAfter) 256 { 257 if (limit2 > 0) 258 limit2 = 1; 259 } 260 else 261 limit2 -= p->keepSizeAfter; 262 if (limit2 < limit) 263 limit = limit2; 264 { 265 UInt32 lenLimit = p->streamPos - p->pos; 266 if (lenLimit > p->matchMaxLen) 267 lenLimit = p->matchMaxLen; 268 p->lenLimit = lenLimit; 269 } 270 p->posLimit = p->pos + limit; 271 } 272 273 void MatchFinder_Init(CMatchFinder *p) 274 { 275 UInt32 i; 276 for (i = 0; i < p->hashSizeSum; i++) 277 p->hash[i] = kEmptyHashValue; 278 p->cyclicBufferPos = 0; 279 p->buffer = p->bufferBase; 280 p->pos = p->streamPos = p->cyclicBufferSize; 281 p->result = SZ_OK; 282 p->streamEndWasReached = 0; 283 MatchFinder_ReadBlock(p); 284 MatchFinder_SetLimits(p); 285 } 286 287 static UInt32 MatchFinder_GetSubValue(CMatchFinder *p) 288 { 289 return (p->pos - p->historySize - 1) & kNormalizeMask; 290 } 291 292 void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, UInt32 numItems) 293 { 294 UInt32 i; 295 for (i = 0; i < numItems; i++) 296 { 297 UInt32 value = items[i]; 298 if (value <= subValue) 299 value = kEmptyHashValue; 300 else 301 value -= subValue; 302 items[i] = value; 303 } 304 } 305 306 static void MatchFinder_Normalize(CMatchFinder *p) 307 { 308 UInt32 subValue = MatchFinder_GetSubValue(p); 309 MatchFinder_Normalize3(subValue, p->hash, p->hashSizeSum + p->numSons); 310 MatchFinder_ReduceOffsets(p, subValue); 311 } 312 313 static void MatchFinder_CheckLimits(CMatchFinder *p) 314 { 315 if (p->pos == kMaxValForNormalize) 316 MatchFinder_Normalize(p); 317 if (!p->streamEndWasReached && p->keepSizeAfter == p->streamPos - p->pos) 318 MatchFinder_CheckAndMoveAndRead(p); 319 if (p->cyclicBufferPos == p->cyclicBufferSize) 320 p->cyclicBufferPos = 0; 321 MatchFinder_SetLimits(p); 322 } 323 324 static UInt32 * Hc_GetMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, 325 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue, 326 UInt32 *distances, UInt32 maxLen) 327 { 328 son[_cyclicBufferPos] = curMatch; 329 for (;;) 330 { 331 UInt32 delta = pos - curMatch; 332 if (cutValue-- == 0 || delta >= _cyclicBufferSize) 333 return distances; 334 { 335 const Byte *pb = cur - delta; 336 curMatch = son[_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)]; 337 if (pb[maxLen] == cur[maxLen] && *pb == *cur) 338 { 339 UInt32 len = 0; 340 while (++len != lenLimit) 341 if (pb[len] != cur[len]) 342 break; 343 if (maxLen < len) 344 { 345 *distances++ = maxLen = len; 346 *distances++ = delta - 1; 347 if (len == lenLimit) 348 return distances; 349 } 350 } 351 } 352 } 353 } 354 355 UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, 356 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue, 357 UInt32 *distances, UInt32 maxLen) 358 { 359 CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1; 360 CLzRef *ptr1 = son + (_cyclicBufferPos << 1); 361 UInt32 len0 = 0, len1 = 0; 362 for (;;) 363 { 364 UInt32 delta = pos - curMatch; 365 if (cutValue-- == 0 || delta >= _cyclicBufferSize) 366 { 367 *ptr0 = *ptr1 = kEmptyHashValue; 368 return distances; 369 } 370 { 371 CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1); 372 const Byte *pb = cur - delta; 373 UInt32 len = (len0 < len1 ? len0 : len1); 374 if (pb[len] == cur[len]) 375 { 376 if (++len != lenLimit && pb[len] == cur[len]) 377 while (++len != lenLimit) 378 if (pb[len] != cur[len]) 379 break; 380 if (maxLen < len) 381 { 382 *distances++ = maxLen = len; 383 *distances++ = delta - 1; 384 if (len == lenLimit) 385 { 386 *ptr1 = pair[0]; 387 *ptr0 = pair[1]; 388 return distances; 389 } 390 } 391 } 392 if (pb[len] < cur[len]) 393 { 394 *ptr1 = curMatch; 395 ptr1 = pair + 1; 396 curMatch = *ptr1; 397 len1 = len; 398 } 399 else 400 { 401 *ptr0 = curMatch; 402 ptr0 = pair; 403 curMatch = *ptr0; 404 len0 = len; 405 } 406 } 407 } 408 } 409 410 static void SkipMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, 411 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue) 412 { 413 CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1; 414 CLzRef *ptr1 = son + (_cyclicBufferPos << 1); 415 UInt32 len0 = 0, len1 = 0; 416 for (;;) 417 { 418 UInt32 delta = pos - curMatch; 419 if (cutValue-- == 0 || delta >= _cyclicBufferSize) 420 { 421 *ptr0 = *ptr1 = kEmptyHashValue; 422 return; 423 } 424 { 425 CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1); 426 const Byte *pb = cur - delta; 427 UInt32 len = (len0 < len1 ? len0 : len1); 428 if (pb[len] == cur[len]) 429 { 430 while (++len != lenLimit) 431 if (pb[len] != cur[len]) 432 break; 433 { 434 if (len == lenLimit) 435 { 436 *ptr1 = pair[0]; 437 *ptr0 = pair[1]; 438 return; 439 } 440 } 441 } 442 if (pb[len] < cur[len]) 443 { 444 *ptr1 = curMatch; 445 ptr1 = pair + 1; 446 curMatch = *ptr1; 447 len1 = len; 448 } 449 else 450 { 451 *ptr0 = curMatch; 452 ptr0 = pair; 453 curMatch = *ptr0; 454 len0 = len; 455 } 456 } 457 } 458 } 459 460 #define MOVE_POS \ 461 ++p->cyclicBufferPos; \ 462 p->buffer++; \ 463 if (++p->pos == p->posLimit) MatchFinder_CheckLimits(p); 464 465 #define MOVE_POS_RET MOVE_POS return offset; 466 467 static void MatchFinder_MovePos(CMatchFinder *p) { MOVE_POS; } 468 469 #define GET_MATCHES_HEADER2(minLen, ret_op) \ 470 UInt32 lenLimit; UInt32 hashValue; const Byte *cur; UInt32 curMatch; \ 471 lenLimit = p->lenLimit; { if (lenLimit < minLen) { MatchFinder_MovePos(p); ret_op; }} \ 472 cur = p->buffer; 473 474 #define GET_MATCHES_HEADER(minLen) GET_MATCHES_HEADER2(minLen, return 0) 475 #define SKIP_HEADER(minLen) GET_MATCHES_HEADER2(minLen, continue) 476 477 #define MF_PARAMS(p) p->pos, p->buffer, p->son, p->cyclicBufferPos, p->cyclicBufferSize, p->cutValue 478 479 #define GET_MATCHES_FOOTER(offset, maxLen) \ 480 offset = (UInt32)(GetMatchesSpec1(lenLimit, curMatch, MF_PARAMS(p), \ 481 distances + offset, maxLen) - distances); MOVE_POS_RET; 482 483 #define SKIP_FOOTER \ 484 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); MOVE_POS; 485 486 static UInt32 Bt2_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 487 { 488 UInt32 offset; 489 GET_MATCHES_HEADER(2) 490 HASH2_CALC; 491 curMatch = p->hash[hashValue]; 492 p->hash[hashValue] = p->pos; 493 offset = 0; 494 GET_MATCHES_FOOTER(offset, 1) 495 } 496 497 UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 498 { 499 UInt32 offset; 500 GET_MATCHES_HEADER(3) 501 HASH_ZIP_CALC; 502 curMatch = p->hash[hashValue]; 503 p->hash[hashValue] = p->pos; 504 offset = 0; 505 GET_MATCHES_FOOTER(offset, 2) 506 } 507 508 static UInt32 Bt3_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 509 { 510 UInt32 hash2Value, delta2, maxLen, offset; 511 GET_MATCHES_HEADER(3) 512 513 HASH3_CALC; 514 515 delta2 = p->pos - p->hash[hash2Value]; 516 curMatch = p->hash[kFix3HashSize + hashValue]; 517 518 p->hash[hash2Value] = 519 p->hash[kFix3HashSize + hashValue] = p->pos; 520 521 522 maxLen = 2; 523 offset = 0; 524 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) 525 { 526 for (; maxLen != lenLimit; maxLen++) 527 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) 528 break; 529 distances[0] = maxLen; 530 distances[1] = delta2 - 1; 531 offset = 2; 532 if (maxLen == lenLimit) 533 { 534 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); 535 MOVE_POS_RET; 536 } 537 } 538 GET_MATCHES_FOOTER(offset, maxLen) 539 } 540 541 static UInt32 Bt4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 542 { 543 UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset; 544 GET_MATCHES_HEADER(4) 545 546 HASH4_CALC; 547 548 delta2 = p->pos - p->hash[ hash2Value]; 549 delta3 = p->pos - p->hash[kFix3HashSize + hash3Value]; 550 curMatch = p->hash[kFix4HashSize + hashValue]; 551 552 p->hash[ hash2Value] = 553 p->hash[kFix3HashSize + hash3Value] = 554 p->hash[kFix4HashSize + hashValue] = p->pos; 555 556 maxLen = 1; 557 offset = 0; 558 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) 559 { 560 distances[0] = maxLen = 2; 561 distances[1] = delta2 - 1; 562 offset = 2; 563 } 564 if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur) 565 { 566 maxLen = 3; 567 distances[offset + 1] = delta3 - 1; 568 offset += 2; 569 delta2 = delta3; 570 } 571 if (offset != 0) 572 { 573 for (; maxLen != lenLimit; maxLen++) 574 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) 575 break; 576 distances[offset - 2] = maxLen; 577 if (maxLen == lenLimit) 578 { 579 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); 580 MOVE_POS_RET; 581 } 582 } 583 if (maxLen < 3) 584 maxLen = 3; 585 GET_MATCHES_FOOTER(offset, maxLen) 586 } 587 588 static UInt32 Hc4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 589 { 590 UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset; 591 GET_MATCHES_HEADER(4) 592 593 HASH4_CALC; 594 595 delta2 = p->pos - p->hash[ hash2Value]; 596 delta3 = p->pos - p->hash[kFix3HashSize + hash3Value]; 597 curMatch = p->hash[kFix4HashSize + hashValue]; 598 599 p->hash[ hash2Value] = 600 p->hash[kFix3HashSize + hash3Value] = 601 p->hash[kFix4HashSize + hashValue] = p->pos; 602 603 maxLen = 1; 604 offset = 0; 605 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) 606 { 607 distances[0] = maxLen = 2; 608 distances[1] = delta2 - 1; 609 offset = 2; 610 } 611 if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur) 612 { 613 maxLen = 3; 614 distances[offset + 1] = delta3 - 1; 615 offset += 2; 616 delta2 = delta3; 617 } 618 if (offset != 0) 619 { 620 for (; maxLen != lenLimit; maxLen++) 621 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) 622 break; 623 distances[offset - 2] = maxLen; 624 if (maxLen == lenLimit) 625 { 626 p->son[p->cyclicBufferPos] = curMatch; 627 MOVE_POS_RET; 628 } 629 } 630 if (maxLen < 3) 631 maxLen = 3; 632 offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p), 633 distances + offset, maxLen) - (distances)); 634 MOVE_POS_RET 635 } 636 637 UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 638 { 639 UInt32 offset; 640 GET_MATCHES_HEADER(3) 641 HASH_ZIP_CALC; 642 curMatch = p->hash[hashValue]; 643 p->hash[hashValue] = p->pos; 644 offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p), 645 distances, 2) - (distances)); 646 MOVE_POS_RET 647 } 648 649 static void Bt2_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 650 { 651 do 652 { 653 SKIP_HEADER(2) 654 HASH2_CALC; 655 curMatch = p->hash[hashValue]; 656 p->hash[hashValue] = p->pos; 657 SKIP_FOOTER 658 } 659 while (--num != 0); 660 } 661 662 void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 663 { 664 do 665 { 666 SKIP_HEADER(3) 667 HASH_ZIP_CALC; 668 curMatch = p->hash[hashValue]; 669 p->hash[hashValue] = p->pos; 670 SKIP_FOOTER 671 } 672 while (--num != 0); 673 } 674 675 static void Bt3_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 676 { 677 do 678 { 679 UInt32 hash2Value; 680 SKIP_HEADER(3) 681 HASH3_CALC; 682 curMatch = p->hash[kFix3HashSize + hashValue]; 683 p->hash[hash2Value] = 684 p->hash[kFix3HashSize + hashValue] = p->pos; 685 SKIP_FOOTER 686 } 687 while (--num != 0); 688 } 689 690 static void Bt4_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 691 { 692 do 693 { 694 UInt32 hash2Value, hash3Value; 695 SKIP_HEADER(4) 696 HASH4_CALC; 697 curMatch = p->hash[kFix4HashSize + hashValue]; 698 p->hash[ hash2Value] = 699 p->hash[kFix3HashSize + hash3Value] = p->pos; 700 p->hash[kFix4HashSize + hashValue] = p->pos; 701 SKIP_FOOTER 702 } 703 while (--num != 0); 704 } 705 706 static void Hc4_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 707 { 708 do 709 { 710 UInt32 hash2Value, hash3Value; 711 SKIP_HEADER(4) 712 HASH4_CALC; 713 curMatch = p->hash[kFix4HashSize + hashValue]; 714 p->hash[ hash2Value] = 715 p->hash[kFix3HashSize + hash3Value] = 716 p->hash[kFix4HashSize + hashValue] = p->pos; 717 p->son[p->cyclicBufferPos] = curMatch; 718 MOVE_POS 719 } 720 while (--num != 0); 721 } 722 723 void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 724 { 725 do 726 { 727 SKIP_HEADER(3) 728 HASH_ZIP_CALC; 729 curMatch = p->hash[hashValue]; 730 p->hash[hashValue] = p->pos; 731 p->son[p->cyclicBufferPos] = curMatch; 732 MOVE_POS 733 } 734 while (--num != 0); 735 } 736 737 void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder *vTable) 738 { 739 vTable->Init = (Mf_Init_Func)MatchFinder_Init; 740 vTable->GetIndexByte = (Mf_GetIndexByte_Func)MatchFinder_GetIndexByte; 741 vTable->GetNumAvailableBytes = (Mf_GetNumAvailableBytes_Func)MatchFinder_GetNumAvailableBytes; 742 vTable->GetPointerToCurrentPos = (Mf_GetPointerToCurrentPos_Func)MatchFinder_GetPointerToCurrentPos; 743 if (!p->btMode) 744 { 745 vTable->GetMatches = (Mf_GetMatches_Func)Hc4_MatchFinder_GetMatches; 746 vTable->Skip = (Mf_Skip_Func)Hc4_MatchFinder_Skip; 747 } 748 else if (p->numHashBytes == 2) 749 { 750 vTable->GetMatches = (Mf_GetMatches_Func)Bt2_MatchFinder_GetMatches; 751 vTable->Skip = (Mf_Skip_Func)Bt2_MatchFinder_Skip; 752 } 753 else if (p->numHashBytes == 3) 754 { 755 vTable->GetMatches = (Mf_GetMatches_Func)Bt3_MatchFinder_GetMatches; 756 vTable->Skip = (Mf_Skip_Func)Bt3_MatchFinder_Skip; 757 } 758 else 759 { 760 vTable->GetMatches = (Mf_GetMatches_Func)Bt4_MatchFinder_GetMatches; 761 vTable->Skip = (Mf_Skip_Func)Bt4_MatchFinder_Skip; 762 } 763 } 764
