1/* LzFind.c -- Match finder for LZ algorithms 22009-04-22 : 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 17static 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 28static 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 45Byte *MatchFinder_GetPointerToCurrentPos(CMatchFinder *p) { return p->buffer; } 46Byte MatchFinder_GetIndexByte(CMatchFinder *p, Int32 index) { return p->buffer[index]; } 47 48UInt32 MatchFinder_GetNumAvailableBytes(CMatchFinder *p) { return p->streamPos - p->pos; } 49 50void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue) 51{ 52 p->posLimit -= subValue; 53 p->pos -= subValue; 54 p->streamPos -= subValue; 55} 56 57static void MatchFinder_ReadBlock(CMatchFinder *p) 58{ 59 if (p->streamEndWasReached || p->result != SZ_OK) 60 return; 61 if (p->directInput) 62 { 63 UInt32 curSize = 0xFFFFFFFF - p->streamPos; 64 if (curSize > p->directInputRem) 65 curSize = (UInt32)p->directInputRem; 66 p->directInputRem -= curSize; 67 p->streamPos += curSize; 68 if (p->directInputRem == 0) 69 p->streamEndWasReached = 1; 70 return; 71 } 72 for (;;) 73 { 74 Byte *dest = p->buffer + (p->streamPos - p->pos); 75 size_t size = (p->bufferBase + p->blockSize - dest); 76 if (size == 0) 77 return; 78 p->result = p->stream->Read(p->stream, dest, &size); 79 if (p->result != SZ_OK) 80 return; 81 if (size == 0) 82 { 83 p->streamEndWasReached = 1; 84 return; 85 } 86 p->streamPos += (UInt32)size; 87 if (p->streamPos - p->pos > p->keepSizeAfter) 88 return; 89 } 90} 91 92void MatchFinder_MoveBlock(CMatchFinder *p) 93{ 94 memmove(p->bufferBase, 95 p->buffer - p->keepSizeBefore, 96 (size_t)(p->streamPos - p->pos + p->keepSizeBefore)); 97 p->buffer = p->bufferBase + p->keepSizeBefore; 98} 99 100int MatchFinder_NeedMove(CMatchFinder *p) 101{ 102 if (p->directInput) 103 return 0; 104 /* if (p->streamEndWasReached) return 0; */ 105 return ((size_t)(p->bufferBase + p->blockSize - p->buffer) <= p->keepSizeAfter); 106} 107 108void MatchFinder_ReadIfRequired(CMatchFinder *p) 109{ 110 if (p->streamEndWasReached) 111 return; 112 if (p->keepSizeAfter >= p->streamPos - p->pos) 113 MatchFinder_ReadBlock(p); 114} 115 116static void MatchFinder_CheckAndMoveAndRead(CMatchFinder *p) 117{ 118 if (MatchFinder_NeedMove(p)) 119 MatchFinder_MoveBlock(p); 120 MatchFinder_ReadBlock(p); 121} 122 123static void MatchFinder_SetDefaultSettings(CMatchFinder *p) 124{ 125 p->cutValue = 32; 126 p->btMode = 1; 127 p->numHashBytes = 4; 128 p->bigHash = 0; 129} 130 131#define kCrcPoly 0xEDB88320 132 133void MatchFinder_Construct(CMatchFinder *p) 134{ 135 UInt32 i; 136 p->bufferBase = 0; 137 p->directInput = 0; 138 p->hash = 0; 139 MatchFinder_SetDefaultSettings(p); 140 141 for (i = 0; i < 256; i++) 142 { 143 UInt32 r = i; 144 int j; 145 for (j = 0; j < 8; j++) 146 r = (r >> 1) ^ (kCrcPoly & ~((r & 1) - 1)); 147 p->crc[i] = r; 148 } 149} 150 151static void MatchFinder_FreeThisClassMemory(CMatchFinder *p, ISzAlloc *alloc) 152{ 153 alloc->Free(alloc, p->hash); 154 p->hash = 0; 155} 156 157void MatchFinder_Free(CMatchFinder *p, ISzAlloc *alloc) 158{ 159 MatchFinder_FreeThisClassMemory(p, alloc); 160 LzInWindow_Free(p, alloc); 161} 162 163static CLzRef* AllocRefs(UInt32 num, ISzAlloc *alloc) 164{ 165 size_t sizeInBytes = (size_t)num * sizeof(CLzRef); 166 if (sizeInBytes / sizeof(CLzRef) != num) 167 return 0; 168 return (CLzRef *)alloc->Alloc(alloc, sizeInBytes); 169} 170 171int MatchFinder_Create(CMatchFinder *p, UInt32 historySize, 172 UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter, 173 ISzAlloc *alloc) 174{ 175 UInt32 sizeReserv; 176 if (historySize > kMaxHistorySize) 177 { 178 MatchFinder_Free(p, alloc); 179 return 0; 180 } 181 sizeReserv = historySize >> 1; 182 if (historySize > ((UInt32)2 << 30)) 183 sizeReserv = historySize >> 2; 184 sizeReserv += (keepAddBufferBefore + matchMaxLen + keepAddBufferAfter) / 2 + (1 << 19); 185 186 p->keepSizeBefore = historySize + keepAddBufferBefore + 1; 187 p->keepSizeAfter = matchMaxLen + keepAddBufferAfter; 188 /* we need one additional byte, since we use MoveBlock after pos++ and before dictionary using */ 189 if (LzInWindow_Create(p, sizeReserv, alloc)) 190 { 191 UInt32 newCyclicBufferSize = historySize + 1; 192 UInt32 hs; 193 p->matchMaxLen = matchMaxLen; 194 { 195 p->fixedHashSize = 0; 196 if (p->numHashBytes == 2) 197 hs = (1 << 16) - 1; 198 else 199 { 200 hs = historySize - 1; 201 hs |= (hs >> 1); 202 hs |= (hs >> 2); 203 hs |= (hs >> 4); 204 hs |= (hs >> 8); 205 hs >>= 1; 206 hs |= 0xFFFF; /* don't change it! It's required for Deflate */ 207 if (hs > (1 << 24)) 208 { 209 if (p->numHashBytes == 3) 210 hs = (1 << 24) - 1; 211 else 212 hs >>= 1; 213 } 214 } 215 p->hashMask = hs; 216 hs++; 217 if (p->numHashBytes > 2) p->fixedHashSize += kHash2Size; 218 if (p->numHashBytes > 3) p->fixedHashSize += kHash3Size; 219 if (p->numHashBytes > 4) p->fixedHashSize += kHash4Size; 220 hs += p->fixedHashSize; 221 } 222 223 { 224 UInt32 prevSize = p->hashSizeSum + p->numSons; 225 UInt32 newSize; 226 p->historySize = historySize; 227 p->hashSizeSum = hs; 228 p->cyclicBufferSize = newCyclicBufferSize; 229 p->numSons = (p->btMode ? newCyclicBufferSize * 2 : newCyclicBufferSize); 230 newSize = p->hashSizeSum + p->numSons; 231 if (p->hash != 0 && prevSize == newSize) 232 return 1; 233 MatchFinder_FreeThisClassMemory(p, alloc); 234 p->hash = AllocRefs(newSize, alloc); 235 if (p->hash != 0) 236 { 237 p->son = p->hash + p->hashSizeSum; 238 return 1; 239 } 240 } 241 } 242 MatchFinder_Free(p, alloc); 243 return 0; 244} 245 246static void MatchFinder_SetLimits(CMatchFinder *p) 247{ 248 UInt32 limit = kMaxValForNormalize - p->pos; 249 UInt32 limit2 = p->cyclicBufferSize - p->cyclicBufferPos; 250 if (limit2 < limit) 251 limit = limit2; 252 limit2 = p->streamPos - p->pos; 253 if (limit2 <= p->keepSizeAfter) 254 { 255 if (limit2 > 0) 256 limit2 = 1; 257 } 258 else 259 limit2 -= p->keepSizeAfter; 260 if (limit2 < limit) 261 limit = limit2; 262 { 263 UInt32 lenLimit = p->streamPos - p->pos; 264 if (lenLimit > p->matchMaxLen) 265 lenLimit = p->matchMaxLen; 266 p->lenLimit = lenLimit; 267 } 268 p->posLimit = p->pos + limit; 269} 270 271void MatchFinder_Init(CMatchFinder *p) 272{ 273 UInt32 i; 274 for (i = 0; i < p->hashSizeSum; i++) 275 p->hash[i] = kEmptyHashValue; 276 p->cyclicBufferPos = 0; 277 p->buffer = p->bufferBase; 278 p->pos = p->streamPos = p->cyclicBufferSize; 279 p->result = SZ_OK; 280 p->streamEndWasReached = 0; 281 MatchFinder_ReadBlock(p); 282 MatchFinder_SetLimits(p); 283} 284 285static UInt32 MatchFinder_GetSubValue(CMatchFinder *p) 286{ 287 return (p->pos - p->historySize - 1) & kNormalizeMask; 288} 289 290void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, UInt32 numItems) 291{ 292 UInt32 i; 293 for (i = 0; i < numItems; i++) 294 { 295 UInt32 value = items[i]; 296 if (value <= subValue) 297 value = kEmptyHashValue; 298 else 299 value -= subValue; 300 items[i] = value; 301 } 302} 303 304static void MatchFinder_Normalize(CMatchFinder *p) 305{ 306 UInt32 subValue = MatchFinder_GetSubValue(p); 307 MatchFinder_Normalize3(subValue, p->hash, p->hashSizeSum + p->numSons); 308 MatchFinder_ReduceOffsets(p, subValue); 309} 310 311static void MatchFinder_CheckLimits(CMatchFinder *p) 312{ 313 if (p->pos == kMaxValForNormalize) 314 MatchFinder_Normalize(p); 315 if (!p->streamEndWasReached && p->keepSizeAfter == p->streamPos - p->pos) 316 MatchFinder_CheckAndMoveAndRead(p); 317 if (p->cyclicBufferPos == p->cyclicBufferSize) 318 p->cyclicBufferPos = 0; 319 MatchFinder_SetLimits(p); 320} 321 322static UInt32 * Hc_GetMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, 323 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue, 324 UInt32 *distances, UInt32 maxLen) 325{ 326 son[_cyclicBufferPos] = curMatch; 327 for (;;) 328 { 329 UInt32 delta = pos - curMatch; 330 if (cutValue-- == 0 || delta >= _cyclicBufferSize) 331 return distances; 332 { 333 const Byte *pb = cur - delta; 334 curMatch = son[_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)]; 335 if (pb[maxLen] == cur[maxLen] && *pb == *cur) 336 { 337 UInt32 len = 0; 338 while (++len != lenLimit) 339 if (pb[len] != cur[len]) 340 break; 341 if (maxLen < len) 342 { 343 *distances++ = maxLen = len; 344 *distances++ = delta - 1; 345 if (len == lenLimit) 346 return distances; 347 } 348 } 349 } 350 } 351} 352 353UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, 354 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue, 355 UInt32 *distances, UInt32 maxLen) 356{ 357 CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1; 358 CLzRef *ptr1 = son + (_cyclicBufferPos << 1); 359 UInt32 len0 = 0, len1 = 0; 360 for (;;) 361 { 362 UInt32 delta = pos - curMatch; 363 if (cutValue-- == 0 || delta >= _cyclicBufferSize) 364 { 365 *ptr0 = *ptr1 = kEmptyHashValue; 366 return distances; 367 } 368 { 369 CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1); 370 const Byte *pb = cur - delta; 371 UInt32 len = (len0 < len1 ? len0 : len1); 372 if (pb[len] == cur[len]) 373 { 374 if (++len != lenLimit && pb[len] == cur[len]) 375 while (++len != lenLimit) 376 if (pb[len] != cur[len]) 377 break; 378 if (maxLen < len) 379 { 380 *distances++ = maxLen = len; 381 *distances++ = delta - 1; 382 if (len == lenLimit) 383 { 384 *ptr1 = pair[0]; 385 *ptr0 = pair[1]; 386 return distances; 387 } 388 } 389 } 390 if (pb[len] < cur[len]) 391 { 392 *ptr1 = curMatch; 393 ptr1 = pair + 1; 394 curMatch = *ptr1; 395 len1 = len; 396 } 397 else 398 { 399 *ptr0 = curMatch; 400 ptr0 = pair; 401 curMatch = *ptr0; 402 len0 = len; 403 } 404 } 405 } 406} 407 408static void SkipMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, 409 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue) 410{ 411 CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1; 412 CLzRef *ptr1 = son + (_cyclicBufferPos << 1); 413 UInt32 len0 = 0, len1 = 0; 414 for (;;) 415 { 416 UInt32 delta = pos - curMatch; 417 if (cutValue-- == 0 || delta >= _cyclicBufferSize) 418 { 419 *ptr0 = *ptr1 = kEmptyHashValue; 420 return; 421 } 422 { 423 CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1); 424 const Byte *pb = cur - delta; 425 UInt32 len = (len0 < len1 ? len0 : len1); 426 if (pb[len] == cur[len]) 427 { 428 while (++len != lenLimit) 429 if (pb[len] != cur[len]) 430 break; 431 { 432 if (len == lenLimit) 433 { 434 *ptr1 = pair[0]; 435 *ptr0 = pair[1]; 436 return; 437 } 438 } 439 } 440 if (pb[len] < cur[len]) 441 { 442 *ptr1 = curMatch; 443 ptr1 = pair + 1; 444 curMatch = *ptr1; 445 len1 = len; 446 } 447 else 448 { 449 *ptr0 = curMatch; 450 ptr0 = pair; 451 curMatch = *ptr0; 452 len0 = len; 453 } 454 } 455 } 456} 457 458#define MOVE_POS \ 459 ++p->cyclicBufferPos; \ 460 p->buffer++; \ 461 if (++p->pos == p->posLimit) MatchFinder_CheckLimits(p); 462 463#define MOVE_POS_RET MOVE_POS return offset; 464 465static void MatchFinder_MovePos(CMatchFinder *p) { MOVE_POS; } 466 467#define GET_MATCHES_HEADER2(minLen, ret_op) \ 468 UInt32 lenLimit; UInt32 hashValue; const Byte *cur; UInt32 curMatch; \ 469 lenLimit = p->lenLimit; { if (lenLimit < minLen) { MatchFinder_MovePos(p); ret_op; }} \ 470 cur = p->buffer; 471 472#define GET_MATCHES_HEADER(minLen) GET_MATCHES_HEADER2(minLen, return 0) 473#define SKIP_HEADER(minLen) GET_MATCHES_HEADER2(minLen, continue) 474 475#define MF_PARAMS(p) p->pos, p->buffer, p->son, p->cyclicBufferPos, p->cyclicBufferSize, p->cutValue 476 477#define GET_MATCHES_FOOTER(offset, maxLen) \ 478 offset = (UInt32)(GetMatchesSpec1(lenLimit, curMatch, MF_PARAMS(p), \ 479 distances + offset, maxLen) - distances); MOVE_POS_RET; 480 481#define SKIP_FOOTER \ 482 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); MOVE_POS; 483 484static UInt32 Bt2_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 485{ 486 UInt32 offset; 487 GET_MATCHES_HEADER(2) 488 HASH2_CALC; 489 curMatch = p->hash[hashValue]; 490 p->hash[hashValue] = p->pos; 491 offset = 0; 492 GET_MATCHES_FOOTER(offset, 1) 493} 494 495UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 496{ 497 UInt32 offset; 498 GET_MATCHES_HEADER(3) 499 HASH_ZIP_CALC; 500 curMatch = p->hash[hashValue]; 501 p->hash[hashValue] = p->pos; 502 offset = 0; 503 GET_MATCHES_FOOTER(offset, 2) 504} 505 506static UInt32 Bt3_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 507{ 508 UInt32 hash2Value, delta2, maxLen, offset; 509 GET_MATCHES_HEADER(3) 510 511 HASH3_CALC; 512 513 delta2 = p->pos - p->hash[hash2Value]; 514 curMatch = p->hash[kFix3HashSize + hashValue]; 515 516 p->hash[hash2Value] = 517 p->hash[kFix3HashSize + hashValue] = p->pos; 518 519 520 maxLen = 2; 521 offset = 0; 522 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) 523 { 524 for (; maxLen != lenLimit; maxLen++) 525 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) 526 break; 527 distances[0] = maxLen; 528 distances[1] = delta2 - 1; 529 offset = 2; 530 if (maxLen == lenLimit) 531 { 532 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); 533 MOVE_POS_RET; 534 } 535 } 536 GET_MATCHES_FOOTER(offset, maxLen) 537} 538 539static UInt32 Bt4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 540{ 541 UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset; 542 GET_MATCHES_HEADER(4) 543 544 HASH4_CALC; 545 546 delta2 = p->pos - p->hash[ hash2Value]; 547 delta3 = p->pos - p->hash[kFix3HashSize + hash3Value]; 548 curMatch = p->hash[kFix4HashSize + hashValue]; 549 550 p->hash[ hash2Value] = 551 p->hash[kFix3HashSize + hash3Value] = 552 p->hash[kFix4HashSize + hashValue] = p->pos; 553 554 maxLen = 1; 555 offset = 0; 556 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) 557 { 558 distances[0] = maxLen = 2; 559 distances[1] = delta2 - 1; 560 offset = 2; 561 } 562 if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur) 563 { 564 maxLen = 3; 565 distances[offset + 1] = delta3 - 1; 566 offset += 2; 567 delta2 = delta3; 568 } 569 if (offset != 0) 570 { 571 for (; maxLen != lenLimit; maxLen++) 572 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) 573 break; 574 distances[offset - 2] = maxLen; 575 if (maxLen == lenLimit) 576 { 577 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); 578 MOVE_POS_RET; 579 } 580 } 581 if (maxLen < 3) 582 maxLen = 3; 583 GET_MATCHES_FOOTER(offset, maxLen) 584} 585 586static UInt32 Hc4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 587{ 588 UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset; 589 GET_MATCHES_HEADER(4) 590 591 HASH4_CALC; 592 593 delta2 = p->pos - p->hash[ hash2Value]; 594 delta3 = p->pos - p->hash[kFix3HashSize + hash3Value]; 595 curMatch = p->hash[kFix4HashSize + hashValue]; 596 597 p->hash[ hash2Value] = 598 p->hash[kFix3HashSize + hash3Value] = 599 p->hash[kFix4HashSize + hashValue] = p->pos; 600 601 maxLen = 1; 602 offset = 0; 603 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) 604 { 605 distances[0] = maxLen = 2; 606 distances[1] = delta2 - 1; 607 offset = 2; 608 } 609 if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur) 610 { 611 maxLen = 3; 612 distances[offset + 1] = delta3 - 1; 613 offset += 2; 614 delta2 = delta3; 615 } 616 if (offset != 0) 617 { 618 for (; maxLen != lenLimit; maxLen++) 619 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) 620 break; 621 distances[offset - 2] = maxLen; 622 if (maxLen == lenLimit) 623 { 624 p->son[p->cyclicBufferPos] = curMatch; 625 MOVE_POS_RET; 626 } 627 } 628 if (maxLen < 3) 629 maxLen = 3; 630 offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p), 631 distances + offset, maxLen) - (distances)); 632 MOVE_POS_RET 633} 634 635UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 636{ 637 UInt32 offset; 638 GET_MATCHES_HEADER(3) 639 HASH_ZIP_CALC; 640 curMatch = p->hash[hashValue]; 641 p->hash[hashValue] = p->pos; 642 offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p), 643 distances, 2) - (distances)); 644 MOVE_POS_RET 645} 646 647static void Bt2_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 648{ 649 do 650 { 651 SKIP_HEADER(2) 652 HASH2_CALC; 653 curMatch = p->hash[hashValue]; 654 p->hash[hashValue] = p->pos; 655 SKIP_FOOTER 656 } 657 while (--num != 0); 658} 659 660void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 661{ 662 do 663 { 664 SKIP_HEADER(3) 665 HASH_ZIP_CALC; 666 curMatch = p->hash[hashValue]; 667 p->hash[hashValue] = p->pos; 668 SKIP_FOOTER 669 } 670 while (--num != 0); 671} 672 673static void Bt3_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 674{ 675 do 676 { 677 UInt32 hash2Value; 678 SKIP_HEADER(3) 679 HASH3_CALC; 680 curMatch = p->hash[kFix3HashSize + hashValue]; 681 p->hash[hash2Value] = 682 p->hash[kFix3HashSize + hashValue] = p->pos; 683 SKIP_FOOTER 684 } 685 while (--num != 0); 686} 687 688static void Bt4_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 689{ 690 do 691 { 692 UInt32 hash2Value, hash3Value; 693 SKIP_HEADER(4) 694 HASH4_CALC; 695 curMatch = p->hash[kFix4HashSize + hashValue]; 696 p->hash[ hash2Value] = 697 p->hash[kFix3HashSize + hash3Value] = p->pos; 698 p->hash[kFix4HashSize + hashValue] = p->pos; 699 SKIP_FOOTER 700 } 701 while (--num != 0); 702} 703 704static void Hc4_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 705{ 706 do 707 { 708 UInt32 hash2Value, hash3Value; 709 SKIP_HEADER(4) 710 HASH4_CALC; 711 curMatch = p->hash[kFix4HashSize + hashValue]; 712 p->hash[ hash2Value] = 713 p->hash[kFix3HashSize + hash3Value] = 714 p->hash[kFix4HashSize + hashValue] = p->pos; 715 p->son[p->cyclicBufferPos] = curMatch; 716 MOVE_POS 717 } 718 while (--num != 0); 719} 720 721void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 722{ 723 do 724 { 725 SKIP_HEADER(3) 726 HASH_ZIP_CALC; 727 curMatch = p->hash[hashValue]; 728 p->hash[hashValue] = p->pos; 729 p->son[p->cyclicBufferPos] = curMatch; 730 MOVE_POS 731 } 732 while (--num != 0); 733} 734 735void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder *vTable) 736{ 737 vTable->Init = (Mf_Init_Func)MatchFinder_Init; 738 vTable->GetIndexByte = (Mf_GetIndexByte_Func)MatchFinder_GetIndexByte; 739 vTable->GetNumAvailableBytes = (Mf_GetNumAvailableBytes_Func)MatchFinder_GetNumAvailableBytes; 740 vTable->GetPointerToCurrentPos = (Mf_GetPointerToCurrentPos_Func)MatchFinder_GetPointerToCurrentPos; 741 if (!p->btMode) 742 { 743 vTable->GetMatches = (Mf_GetMatches_Func)Hc4_MatchFinder_GetMatches; 744 vTable->Skip = (Mf_Skip_Func)Hc4_MatchFinder_Skip; 745 } 746 else if (p->numHashBytes == 2) 747 { 748 vTable->GetMatches = (Mf_GetMatches_Func)Bt2_MatchFinder_GetMatches; 749 vTable->Skip = (Mf_Skip_Func)Bt2_MatchFinder_Skip; 750 } 751 else if (p->numHashBytes == 3) 752 { 753 vTable->GetMatches = (Mf_GetMatches_Func)Bt3_MatchFinder_GetMatches; 754 vTable->Skip = (Mf_Skip_Func)Bt3_MatchFinder_Skip; 755 } 756 else 757 { 758 vTable->GetMatches = (Mf_GetMatches_Func)Bt4_MatchFinder_GetMatches; 759 vTable->Skip = (Mf_Skip_Func)Bt4_MatchFinder_Skip; 760 } 761} 762