1 /* LzFind.c -- Match finder for LZ algorithms 2 2008-10-04 : Igor Pavlov : Public domain */ 3 4 #include <string.h> 5 6 #include "LzFind.h" 7 #include "LzHash.h" 8 9 #define kEmptyHashValue 0 10 #define kMaxValForNormalize ((UInt32)0xFFFFFFFF) 11 #define kNormalizeStepMin (1 << 10) /* it must be power of 2 */ 12 #define kNormalizeMask (~(kNormalizeStepMin - 1)) 13 #define kMaxHistorySize ((UInt32)3 << 30) 14 15 #define kStartMaxLen 3 16 17 static void LzInWindow_Free(CMatchFinder *p, ISzAlloc *alloc) 18 { 19 if (!p->directInput) 20 { 21 alloc->Free(alloc, p->bufferBase); 22 p->bufferBase = 0; 23 } 24 } 25 26 /* keepSizeBefore + keepSizeAfter + keepSizeReserv must be < 4G) */ 27 28 static int LzInWindow_Create(CMatchFinder *p, UInt32 keepSizeReserv, ISzAlloc *alloc) 29 { 30 UInt32 blockSize = p->keepSizeBefore + p->keepSizeAfter + keepSizeReserv; 31 if (p->directInput) 32 { 33 p->blockSize = blockSize; 34 return 1; 35 } 36 if (p->bufferBase == 0 || p->blockSize != blockSize) 37 { 38 LzInWindow_Free(p, alloc); 39 p->blockSize = blockSize; 40 p->bufferBase = (Byte *)alloc->Alloc(alloc, (size_t)blockSize); 41 } 42 return (p->bufferBase != 0); 43 } 44 45 Byte *MatchFinder_GetPointerToCurrentPos(CMatchFinder *p) { return p->buffer; } 46 Byte MatchFinder_GetIndexByte(CMatchFinder *p, Int32 index) { return p->buffer[index]; } 47 48 UInt32 MatchFinder_GetNumAvailableBytes(CMatchFinder *p) { return p->streamPos - p->pos; } 49 50 void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue) 51 { 52 p->posLimit -= subValue; 53 p->pos -= subValue; 54 p->streamPos -= subValue; 55 } 56 57 static void MatchFinder_ReadBlock(CMatchFinder *p) 58 { 59 if (p->streamEndWasReached || p->result != SZ_OK) 60 return; 61 for (;;) 62 { 63 Byte *dest = p->buffer + (p->streamPos - p->pos); 64 size_t size = (p->bufferBase + p->blockSize - dest); 65 if (size == 0) 66 return; 67 p->result = p->stream->Read(p->stream, dest, &size); 68 if (p->result != SZ_OK) 69 return; 70 if (size == 0) 71 { 72 p->streamEndWasReached = 1; 73 return; 74 } 75 p->streamPos += (UInt32)size; 76 if (p->streamPos - p->pos > p->keepSizeAfter) 77 return; 78 } 79 } 80 81 void MatchFinder_MoveBlock(CMatchFinder *p) 82 { 83 memmove(p->bufferBase, 84 p->buffer - p->keepSizeBefore, 85 (size_t)(p->streamPos - p->pos + p->keepSizeBefore)); 86 p->buffer = p->bufferBase + p->keepSizeBefore; 87 } 88 89 int MatchFinder_NeedMove(CMatchFinder *p) 90 { 91 /* if (p->streamEndWasReached) return 0; */ 92 return ((size_t)(p->bufferBase + p->blockSize - p->buffer) <= p->keepSizeAfter); 93 } 94 95 void MatchFinder_ReadIfRequired(CMatchFinder *p) 96 { 97 if (p->streamEndWasReached) 98 return; 99 if (p->keepSizeAfter >= p->streamPos - p->pos) 100 MatchFinder_ReadBlock(p); 101 } 102 103 static void MatchFinder_CheckAndMoveAndRead(CMatchFinder *p) 104 { 105 if (MatchFinder_NeedMove(p)) 106 MatchFinder_MoveBlock(p); 107 MatchFinder_ReadBlock(p); 108 } 109 110 static void MatchFinder_SetDefaultSettings(CMatchFinder *p) 111 { 112 p->cutValue = 32; 113 p->btMode = 1; 114 p->numHashBytes = 4; 115 /* p->skipModeBits = 0; */ 116 p->directInput = 0; 117 p->bigHash = 0; 118 } 119 120 #define kCrcPoly 0xEDB88320 121 122 void MatchFinder_Construct(CMatchFinder *p) 123 { 124 UInt32 i; 125 p->bufferBase = 0; 126 p->directInput = 0; 127 p->hash = 0; 128 MatchFinder_SetDefaultSettings(p); 129 130 for (i = 0; i < 256; i++) 131 { 132 UInt32 r = i; 133 int j; 134 for (j = 0; j < 8; j++) 135 r = (r >> 1) ^ (kCrcPoly & ~((r & 1) - 1)); 136 p->crc[i] = r; 137 } 138 } 139 140 static void MatchFinder_FreeThisClassMemory(CMatchFinder *p, ISzAlloc *alloc) 141 { 142 alloc->Free(alloc, p->hash); 143 p->hash = 0; 144 } 145 146 void MatchFinder_Free(CMatchFinder *p, ISzAlloc *alloc) 147 { 148 MatchFinder_FreeThisClassMemory(p, alloc); 149 LzInWindow_Free(p, alloc); 150 } 151 152 static CLzRef* AllocRefs(UInt32 num, ISzAlloc *alloc) 153 { 154 size_t sizeInBytes = (size_t)num * sizeof(CLzRef); 155 if (sizeInBytes / sizeof(CLzRef) != num) 156 return 0; 157 return (CLzRef *)alloc->Alloc(alloc, sizeInBytes); 158 } 159 160 int MatchFinder_Create(CMatchFinder *p, UInt32 historySize, 161 UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter, 162 ISzAlloc *alloc) 163 { 164 UInt32 sizeReserv; 165 if (historySize > kMaxHistorySize) 166 { 167 MatchFinder_Free(p, alloc); 168 return 0; 169 } 170 sizeReserv = historySize >> 1; 171 if (historySize > ((UInt32)2 << 30)) 172 sizeReserv = historySize >> 2; 173 sizeReserv += (keepAddBufferBefore + matchMaxLen + keepAddBufferAfter) / 2 + (1 << 19); 174 175 p->keepSizeBefore = historySize + keepAddBufferBefore + 1; 176 p->keepSizeAfter = matchMaxLen + keepAddBufferAfter; 177 /* we need one additional byte, since we use MoveBlock after pos++ and before dictionary using */ 178 if (LzInWindow_Create(p, sizeReserv, alloc)) 179 { 180 UInt32 newCyclicBufferSize = (historySize /* >> p->skipModeBits */) + 1; 181 UInt32 hs; 182 p->matchMaxLen = matchMaxLen; 183 { 184 p->fixedHashSize = 0; 185 if (p->numHashBytes == 2) 186 hs = (1 << 16) - 1; 187 else 188 { 189 hs = historySize - 1; 190 hs |= (hs >> 1); 191 hs |= (hs >> 2); 192 hs |= (hs >> 4); 193 hs |= (hs >> 8); 194 hs >>= 1; 195 /* hs >>= p->skipModeBits; */ 196 hs |= 0xFFFF; /* don't change it! It's required for Deflate */ 197 if (hs > (1 << 24)) 198 { 199 if (p->numHashBytes == 3) 200 hs = (1 << 24) - 1; 201 else 202 hs >>= 1; 203 } 204 } 205 p->hashMask = hs; 206 hs++; 207 if (p->numHashBytes > 2) p->fixedHashSize += kHash2Size; 208 if (p->numHashBytes > 3) p->fixedHashSize += kHash3Size; 209 if (p->numHashBytes > 4) p->fixedHashSize += kHash4Size; 210 hs += p->fixedHashSize; 211 } 212 213 { 214 UInt32 prevSize = p->hashSizeSum + p->numSons; 215 UInt32 newSize; 216 p->historySize = historySize; 217 p->hashSizeSum = hs; 218 p->cyclicBufferSize = newCyclicBufferSize; 219 p->numSons = (p->btMode ? newCyclicBufferSize * 2 : newCyclicBufferSize); 220 newSize = p->hashSizeSum + p->numSons; 221 if (p->hash != 0 && prevSize == newSize) 222 return 1; 223 MatchFinder_FreeThisClassMemory(p, alloc); 224 p->hash = AllocRefs(newSize, alloc); 225 if (p->hash != 0) 226 { 227 p->son = p->hash + p->hashSizeSum; 228 return 1; 229 } 230 } 231 } 232 MatchFinder_Free(p, alloc); 233 return 0; 234 } 235 236 static void MatchFinder_SetLimits(CMatchFinder *p) 237 { 238 UInt32 limit = kMaxValForNormalize - p->pos; 239 UInt32 limit2 = p->cyclicBufferSize - p->cyclicBufferPos; 240 if (limit2 < limit) 241 limit = limit2; 242 limit2 = p->streamPos - p->pos; 243 if (limit2 <= p->keepSizeAfter) 244 { 245 if (limit2 > 0) 246 limit2 = 1; 247 } 248 else 249 limit2 -= p->keepSizeAfter; 250 if (limit2 < limit) 251 limit = limit2; 252 { 253 UInt32 lenLimit = p->streamPos - p->pos; 254 if (lenLimit > p->matchMaxLen) 255 lenLimit = p->matchMaxLen; 256 p->lenLimit = lenLimit; 257 } 258 p->posLimit = p->pos + limit; 259 } 260 261 void MatchFinder_Init(CMatchFinder *p) 262 { 263 UInt32 i; 264 for (i = 0; i < p->hashSizeSum; i++) 265 p->hash[i] = kEmptyHashValue; 266 p->cyclicBufferPos = 0; 267 p->buffer = p->bufferBase; 268 p->pos = p->streamPos = p->cyclicBufferSize; 269 p->result = SZ_OK; 270 p->streamEndWasReached = 0; 271 MatchFinder_ReadBlock(p); 272 MatchFinder_SetLimits(p); 273 } 274 275 static UInt32 MatchFinder_GetSubValue(CMatchFinder *p) 276 { 277 return (p->pos - p->historySize - 1) & kNormalizeMask; 278 } 279 280 void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, UInt32 numItems) 281 { 282 UInt32 i; 283 for (i = 0; i < numItems; i++) 284 { 285 UInt32 value = items[i]; 286 if (value <= subValue) 287 value = kEmptyHashValue; 288 else 289 value -= subValue; 290 items[i] = value; 291 } 292 } 293 294 static void MatchFinder_Normalize(CMatchFinder *p) 295 { 296 UInt32 subValue = MatchFinder_GetSubValue(p); 297 MatchFinder_Normalize3(subValue, p->hash, p->hashSizeSum + p->numSons); 298 MatchFinder_ReduceOffsets(p, subValue); 299 } 300 301 static void MatchFinder_CheckLimits(CMatchFinder *p) 302 { 303 if (p->pos == kMaxValForNormalize) 304 MatchFinder_Normalize(p); 305 if (!p->streamEndWasReached && p->keepSizeAfter == p->streamPos - p->pos) 306 MatchFinder_CheckAndMoveAndRead(p); 307 if (p->cyclicBufferPos == p->cyclicBufferSize) 308 p->cyclicBufferPos = 0; 309 MatchFinder_SetLimits(p); 310 } 311 312 static UInt32 * Hc_GetMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, 313 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue, 314 UInt32 *distances, UInt32 maxLen) 315 { 316 son[_cyclicBufferPos] = curMatch; 317 for (;;) 318 { 319 UInt32 delta = pos - curMatch; 320 if (cutValue-- == 0 || delta >= _cyclicBufferSize) 321 return distances; 322 { 323 const Byte *pb = cur - delta; 324 curMatch = son[_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)]; 325 if (pb[maxLen] == cur[maxLen] && *pb == *cur) 326 { 327 UInt32 len = 0; 328 while (++len != lenLimit) 329 if (pb[len] != cur[len]) 330 break; 331 if (maxLen < len) 332 { 333 *distances++ = maxLen = len; 334 *distances++ = delta - 1; 335 if (len == lenLimit) 336 return distances; 337 } 338 } 339 } 340 } 341 } 342 343 UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, 344 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue, 345 UInt32 *distances, UInt32 maxLen) 346 { 347 CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1; 348 CLzRef *ptr1 = son + (_cyclicBufferPos << 1); 349 UInt32 len0 = 0, len1 = 0; 350 for (;;) 351 { 352 UInt32 delta = pos - curMatch; 353 if (cutValue-- == 0 || delta >= _cyclicBufferSize) 354 { 355 *ptr0 = *ptr1 = kEmptyHashValue; 356 return distances; 357 } 358 { 359 CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1); 360 const Byte *pb = cur - delta; 361 UInt32 len = (len0 < len1 ? len0 : len1); 362 if (pb[len] == cur[len]) 363 { 364 if (++len != lenLimit && pb[len] == cur[len]) 365 while (++len != lenLimit) 366 if (pb[len] != cur[len]) 367 break; 368 if (maxLen < len) 369 { 370 *distances++ = maxLen = len; 371 *distances++ = delta - 1; 372 if (len == lenLimit) 373 { 374 *ptr1 = pair[0]; 375 *ptr0 = pair[1]; 376 return distances; 377 } 378 } 379 } 380 if (pb[len] < cur[len]) 381 { 382 *ptr1 = curMatch; 383 ptr1 = pair + 1; 384 curMatch = *ptr1; 385 len1 = len; 386 } 387 else 388 { 389 *ptr0 = curMatch; 390 ptr0 = pair; 391 curMatch = *ptr0; 392 len0 = len; 393 } 394 } 395 } 396 } 397 398 static void SkipMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, 399 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue) 400 { 401 CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1; 402 CLzRef *ptr1 = son + (_cyclicBufferPos << 1); 403 UInt32 len0 = 0, len1 = 0; 404 for (;;) 405 { 406 UInt32 delta = pos - curMatch; 407 if (cutValue-- == 0 || delta >= _cyclicBufferSize) 408 { 409 *ptr0 = *ptr1 = kEmptyHashValue; 410 return; 411 } 412 { 413 CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1); 414 const Byte *pb = cur - delta; 415 UInt32 len = (len0 < len1 ? len0 : len1); 416 if (pb[len] == cur[len]) 417 { 418 while (++len != lenLimit) 419 if (pb[len] != cur[len]) 420 break; 421 { 422 if (len == lenLimit) 423 { 424 *ptr1 = pair[0]; 425 *ptr0 = pair[1]; 426 return; 427 } 428 } 429 } 430 if (pb[len] < cur[len]) 431 { 432 *ptr1 = curMatch; 433 ptr1 = pair + 1; 434 curMatch = *ptr1; 435 len1 = len; 436 } 437 else 438 { 439 *ptr0 = curMatch; 440 ptr0 = pair; 441 curMatch = *ptr0; 442 len0 = len; 443 } 444 } 445 } 446 } 447 448 #define MOVE_POS \ 449 ++p->cyclicBufferPos; \ 450 p->buffer++; \ 451 if (++p->pos == p->posLimit) MatchFinder_CheckLimits(p); 452 453 #define MOVE_POS_RET MOVE_POS return offset; 454 455 static void MatchFinder_MovePos(CMatchFinder *p) { MOVE_POS; } 456 457 #define GET_MATCHES_HEADER2(minLen, ret_op) \ 458 UInt32 lenLimit; UInt32 hashValue; const Byte *cur; UInt32 curMatch; \ 459 lenLimit = p->lenLimit; { if (lenLimit < minLen) { MatchFinder_MovePos(p); ret_op; }} \ 460 cur = p->buffer; 461 462 #define GET_MATCHES_HEADER(minLen) GET_MATCHES_HEADER2(minLen, return 0) 463 #define SKIP_HEADER(minLen) GET_MATCHES_HEADER2(minLen, continue) 464 465 #define MF_PARAMS(p) p->pos, p->buffer, p->son, p->cyclicBufferPos, p->cyclicBufferSize, p->cutValue 466 467 #define GET_MATCHES_FOOTER(offset, maxLen) \ 468 offset = (UInt32)(GetMatchesSpec1(lenLimit, curMatch, MF_PARAMS(p), \ 469 distances + offset, maxLen) - distances); MOVE_POS_RET; 470 471 #define SKIP_FOOTER \ 472 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); MOVE_POS; 473 474 static UInt32 Bt2_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 475 { 476 UInt32 offset; 477 GET_MATCHES_HEADER(2) 478 HASH2_CALC; 479 curMatch = p->hash[hashValue]; 480 p->hash[hashValue] = p->pos; 481 offset = 0; 482 GET_MATCHES_FOOTER(offset, 1) 483 } 484 485 UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 486 { 487 UInt32 offset; 488 GET_MATCHES_HEADER(3) 489 HASH_ZIP_CALC; 490 curMatch = p->hash[hashValue]; 491 p->hash[hashValue] = p->pos; 492 offset = 0; 493 GET_MATCHES_FOOTER(offset, 2) 494 } 495 496 static UInt32 Bt3_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 497 { 498 UInt32 hash2Value, delta2, maxLen, offset; 499 GET_MATCHES_HEADER(3) 500 501 HASH3_CALC; 502 503 delta2 = p->pos - p->hash[hash2Value]; 504 curMatch = p->hash[kFix3HashSize + hashValue]; 505 506 p->hash[hash2Value] = 507 p->hash[kFix3HashSize + hashValue] = p->pos; 508 509 510 maxLen = 2; 511 offset = 0; 512 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) 513 { 514 for (; maxLen != lenLimit; maxLen++) 515 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) 516 break; 517 distances[0] = maxLen; 518 distances[1] = delta2 - 1; 519 offset = 2; 520 if (maxLen == lenLimit) 521 { 522 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); 523 MOVE_POS_RET; 524 } 525 } 526 GET_MATCHES_FOOTER(offset, maxLen) 527 } 528 529 static UInt32 Bt4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 530 { 531 UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset; 532 GET_MATCHES_HEADER(4) 533 534 HASH4_CALC; 535 536 delta2 = p->pos - p->hash[ hash2Value]; 537 delta3 = p->pos - p->hash[kFix3HashSize + hash3Value]; 538 curMatch = p->hash[kFix4HashSize + hashValue]; 539 540 p->hash[ hash2Value] = 541 p->hash[kFix3HashSize + hash3Value] = 542 p->hash[kFix4HashSize + hashValue] = p->pos; 543 544 maxLen = 1; 545 offset = 0; 546 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) 547 { 548 distances[0] = maxLen = 2; 549 distances[1] = delta2 - 1; 550 offset = 2; 551 } 552 if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur) 553 { 554 maxLen = 3; 555 distances[offset + 1] = delta3 - 1; 556 offset += 2; 557 delta2 = delta3; 558 } 559 if (offset != 0) 560 { 561 for (; maxLen != lenLimit; maxLen++) 562 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) 563 break; 564 distances[offset - 2] = maxLen; 565 if (maxLen == lenLimit) 566 { 567 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); 568 MOVE_POS_RET; 569 } 570 } 571 if (maxLen < 3) 572 maxLen = 3; 573 GET_MATCHES_FOOTER(offset, maxLen) 574 } 575 576 static UInt32 Hc4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 577 { 578 UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset; 579 GET_MATCHES_HEADER(4) 580 581 HASH4_CALC; 582 583 delta2 = p->pos - p->hash[ hash2Value]; 584 delta3 = p->pos - p->hash[kFix3HashSize + hash3Value]; 585 curMatch = p->hash[kFix4HashSize + hashValue]; 586 587 p->hash[ hash2Value] = 588 p->hash[kFix3HashSize + hash3Value] = 589 p->hash[kFix4HashSize + hashValue] = p->pos; 590 591 maxLen = 1; 592 offset = 0; 593 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) 594 { 595 distances[0] = maxLen = 2; 596 distances[1] = delta2 - 1; 597 offset = 2; 598 } 599 if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur) 600 { 601 maxLen = 3; 602 distances[offset + 1] = delta3 - 1; 603 offset += 2; 604 delta2 = delta3; 605 } 606 if (offset != 0) 607 { 608 for (; maxLen != lenLimit; maxLen++) 609 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) 610 break; 611 distances[offset - 2] = maxLen; 612 if (maxLen == lenLimit) 613 { 614 p->son[p->cyclicBufferPos] = curMatch; 615 MOVE_POS_RET; 616 } 617 } 618 if (maxLen < 3) 619 maxLen = 3; 620 offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p), 621 distances + offset, maxLen) - (distances)); 622 MOVE_POS_RET 623 } 624 625 UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 626 { 627 UInt32 offset; 628 GET_MATCHES_HEADER(3) 629 HASH_ZIP_CALC; 630 curMatch = p->hash[hashValue]; 631 p->hash[hashValue] = p->pos; 632 offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p), 633 distances, 2) - (distances)); 634 MOVE_POS_RET 635 } 636 637 static void Bt2_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 638 { 639 do 640 { 641 SKIP_HEADER(2) 642 HASH2_CALC; 643 curMatch = p->hash[hashValue]; 644 p->hash[hashValue] = p->pos; 645 SKIP_FOOTER 646 } 647 while (--num != 0); 648 } 649 650 void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 651 { 652 do 653 { 654 SKIP_HEADER(3) 655 HASH_ZIP_CALC; 656 curMatch = p->hash[hashValue]; 657 p->hash[hashValue] = p->pos; 658 SKIP_FOOTER 659 } 660 while (--num != 0); 661 } 662 663 static void Bt3_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 664 { 665 do 666 { 667 UInt32 hash2Value; 668 SKIP_HEADER(3) 669 HASH3_CALC; 670 curMatch = p->hash[kFix3HashSize + hashValue]; 671 p->hash[hash2Value] = 672 p->hash[kFix3HashSize + hashValue] = p->pos; 673 SKIP_FOOTER 674 } 675 while (--num != 0); 676 } 677 678 static void Bt4_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 679 { 680 do 681 { 682 UInt32 hash2Value, hash3Value; 683 SKIP_HEADER(4) 684 HASH4_CALC; 685 curMatch = p->hash[kFix4HashSize + hashValue]; 686 p->hash[ hash2Value] = 687 p->hash[kFix3HashSize + hash3Value] = p->pos; 688 p->hash[kFix4HashSize + hashValue] = p->pos; 689 SKIP_FOOTER 690 } 691 while (--num != 0); 692 } 693 694 static void Hc4_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 695 { 696 do 697 { 698 UInt32 hash2Value, hash3Value; 699 SKIP_HEADER(4) 700 HASH4_CALC; 701 curMatch = p->hash[kFix4HashSize + hashValue]; 702 p->hash[ hash2Value] = 703 p->hash[kFix3HashSize + hash3Value] = 704 p->hash[kFix4HashSize + hashValue] = p->pos; 705 p->son[p->cyclicBufferPos] = curMatch; 706 MOVE_POS 707 } 708 while (--num != 0); 709 } 710 711 void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 712 { 713 do 714 { 715 SKIP_HEADER(3) 716 HASH_ZIP_CALC; 717 curMatch = p->hash[hashValue]; 718 p->hash[hashValue] = p->pos; 719 p->son[p->cyclicBufferPos] = curMatch; 720 MOVE_POS 721 } 722 while (--num != 0); 723 } 724 725 void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder *vTable) 726 { 727 vTable->Init = (Mf_Init_Func)MatchFinder_Init; 728 vTable->GetIndexByte = (Mf_GetIndexByte_Func)MatchFinder_GetIndexByte; 729 vTable->GetNumAvailableBytes = (Mf_GetNumAvailableBytes_Func)MatchFinder_GetNumAvailableBytes; 730 vTable->GetPointerToCurrentPos = (Mf_GetPointerToCurrentPos_Func)MatchFinder_GetPointerToCurrentPos; 731 if (!p->btMode) 732 { 733 vTable->GetMatches = (Mf_GetMatches_Func)Hc4_MatchFinder_GetMatches; 734 vTable->Skip = (Mf_Skip_Func)Hc4_MatchFinder_Skip; 735 } 736 else if (p->numHashBytes == 2) 737 { 738 vTable->GetMatches = (Mf_GetMatches_Func)Bt2_MatchFinder_GetMatches; 739 vTable->Skip = (Mf_Skip_Func)Bt2_MatchFinder_Skip; 740 } 741 else if (p->numHashBytes == 3) 742 { 743 vTable->GetMatches = (Mf_GetMatches_Func)Bt3_MatchFinder_GetMatches; 744 vTable->Skip = (Mf_Skip_Func)Bt3_MatchFinder_Skip; 745 } 746 else 747 { 748 vTable->GetMatches = (Mf_GetMatches_Func)Bt4_MatchFinder_GetMatches; 749 vTable->Skip = (Mf_Skip_Func)Bt4_MatchFinder_Skip; 750 } 751 } 752
