1 /* 2 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 3 * Use is subject to license terms. 4 */ 5 6 /* LzFind.c -- Match finder for LZ algorithms 7 2008-10-04 : Igor Pavlov : Public domain */ 8 9 #include <string.h> 10 11 #include "LzFind.h" 12 #include "LzHash.h" 13 14 #define kEmptyHashValue 0 15 #define kMaxValForNormalize ((UInt32)0xFFFFFFFF) 16 #define kNormalizeStepMin (1 << 10) /* it must be power of 2 */ 17 #define kNormalizeMask (~(kNormalizeStepMin - 1)) 18 #define kMaxHistorySize ((UInt32)3 << 30) 19 20 #define kStartMaxLen 3 21 22 static void LzInWindow_Free(CMatchFinder *p, ISzAlloc *alloc) 23 { 24 if (!p->directInput) 25 { 26 alloc->Free(alloc, p->bufferBase, 0); 27 p->bufferBase = 0; 28 } 29 } 30 31 /* keepSizeBefore + keepSizeAfter + keepSizeReserv must be < 4G) */ 32 33 static int LzInWindow_Create(CMatchFinder *p, UInt32 keepSizeReserv, ISzAlloc *alloc) 34 { 35 UInt32 blockSize = p->keepSizeBefore + p->keepSizeAfter + keepSizeReserv; 36 if (p->directInput) 37 { 38 p->blockSize = blockSize; 39 return 1; 40 } 41 if (p->bufferBase == 0 || p->blockSize != blockSize) 42 { 43 LzInWindow_Free(p, alloc); 44 p->blockSize = blockSize; 45 p->bufferBase = (Byte *)alloc->Alloc(alloc, (size_t)blockSize); 46 } 47 return (p->bufferBase != 0); 48 } 49 50 Byte *MatchFinder_GetPointerToCurrentPos(CMatchFinder *p) { return p->buffer; } 51 Byte MatchFinder_GetIndexByte(CMatchFinder *p, Int32 index) { return p->buffer[index]; } 52 53 UInt32 MatchFinder_GetNumAvailableBytes(CMatchFinder *p) { return p->streamPos - p->pos; } 54 55 void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue) 56 { 57 p->posLimit -= subValue; 58 p->pos -= subValue; 59 p->streamPos -= subValue; 60 } 61 62 static void MatchFinder_ReadBlock(CMatchFinder *p) 63 { 64 if (p->streamEndWasReached || p->result != SZ_OK) 65 return; 66 for (;;) 67 { 68 Byte *dest = p->buffer + (p->streamPos - p->pos); 69 size_t size = (p->bufferBase + p->blockSize - dest); 70 if (size == 0) 71 return; 72 p->result = p->stream->Read(p->stream, dest, &size); 73 if (p->result != SZ_OK) 74 return; 75 if (size == 0) 76 { 77 p->streamEndWasReached = 1; 78 return; 79 } 80 p->streamPos += (UInt32)size; 81 if (p->streamPos - p->pos > p->keepSizeAfter) 82 return; 83 } 84 } 85 86 void MatchFinder_MoveBlock(CMatchFinder *p) 87 { 88 memmove(p->bufferBase, 89 p->buffer - p->keepSizeBefore, 90 (size_t)(p->streamPos - p->pos + p->keepSizeBefore)); 91 p->buffer = p->bufferBase + p->keepSizeBefore; 92 } 93 94 int MatchFinder_NeedMove(CMatchFinder *p) 95 { 96 /* if (p->streamEndWasReached) return 0; */ 97 return ((size_t)(p->bufferBase + p->blockSize - p->buffer) <= p->keepSizeAfter); 98 } 99 100 void MatchFinder_ReadIfRequired(CMatchFinder *p) 101 { 102 if (p->streamEndWasReached) 103 return; 104 if (p->keepSizeAfter >= p->streamPos - p->pos) 105 MatchFinder_ReadBlock(p); 106 } 107 108 static void MatchFinder_CheckAndMoveAndRead(CMatchFinder *p) 109 { 110 if (MatchFinder_NeedMove(p)) 111 MatchFinder_MoveBlock(p); 112 MatchFinder_ReadBlock(p); 113 } 114 115 static void MatchFinder_SetDefaultSettings(CMatchFinder *p) 116 { 117 p->cutValue = 32; 118 p->btMode = 1; 119 p->numHashBytes = 4; 120 /* p->skipModeBits = 0; */ 121 p->directInput = 0; 122 p->bigHash = 0; 123 } 124 125 #define kCrcPoly 0xEDB88320 126 127 void MatchFinder_Construct(CMatchFinder *p) 128 { 129 UInt32 i; 130 p->bufferBase = 0; 131 p->directInput = 0; 132 p->hash = 0; 133 MatchFinder_SetDefaultSettings(p); 134 135 for (i = 0; i < 256; i++) 136 { 137 UInt32 r = i; 138 int j; 139 for (j = 0; j < 8; j++) 140 r = (r >> 1) ^ (kCrcPoly & ~((r & 1) - 1)); 141 p->crc[i] = r; 142 } 143 } 144 145 static void MatchFinder_FreeThisClassMemory(CMatchFinder *p, ISzAlloc *alloc) 146 { 147 alloc->Free(alloc, p->hash, 0); 148 p->hash = 0; 149 } 150 151 void MatchFinder_Free(CMatchFinder *p, ISzAlloc *alloc) 152 { 153 MatchFinder_FreeThisClassMemory(p, alloc); 154 LzInWindow_Free(p, alloc); 155 } 156 157 static CLzRef* AllocRefs(UInt32 num, ISzAlloc *alloc) 158 { 159 size_t sizeInBytes = (size_t)num * sizeof(CLzRef); 160 if (sizeInBytes / sizeof(CLzRef) != num) 161 return 0; 162 return (CLzRef *)alloc->Alloc(alloc, sizeInBytes); 163 } 164 165 int MatchFinder_Create(CMatchFinder *p, UInt32 historySize, 166 UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter, 167 ISzAlloc *alloc) 168 { 169 UInt32 sizeReserv; 170 if (historySize > kMaxHistorySize) 171 { 172 MatchFinder_Free(p, alloc); 173 return 0; 174 } 175 sizeReserv = historySize >> 1; 176 if (historySize > ((UInt32)2 << 30)) 177 sizeReserv = historySize >> 2; 178 sizeReserv += (keepAddBufferBefore + matchMaxLen + keepAddBufferAfter) / 2 + (1 << 19); 179 180 p->keepSizeBefore = historySize + keepAddBufferBefore + 1; 181 p->keepSizeAfter = matchMaxLen + keepAddBufferAfter; 182 /* we need one additional byte, since we use MoveBlock after pos++ and before dictionary using */ 183 if (LzInWindow_Create(p, sizeReserv, alloc)) 184 { 185 UInt32 newCyclicBufferSize = (historySize /* >> p->skipModeBits */) + 1; 186 UInt32 hs; 187 p->matchMaxLen = matchMaxLen; 188 { 189 p->fixedHashSize = 0; 190 if (p->numHashBytes == 2) 191 hs = (1 << 16) - 1; 192 else 193 { 194 hs = historySize - 1; 195 hs |= (hs >> 1); 196 hs |= (hs >> 2); 197 hs |= (hs >> 4); 198 hs |= (hs >> 8); 199 hs >>= 1; 200 /* hs >>= p->skipModeBits; */ 201 hs |= 0xFFFF; /* don't change it! It's required for Deflate */ 202 if (hs > (1 << 24)) 203 { 204 if (p->numHashBytes == 3) 205 hs = (1 << 24) - 1; 206 else 207 hs >>= 1; 208 } 209 } 210 p->hashMask = hs; 211 hs++; 212 if (p->numHashBytes > 2) p->fixedHashSize += kHash2Size; 213 if (p->numHashBytes > 3) p->fixedHashSize += kHash3Size; 214 if (p->numHashBytes > 4) p->fixedHashSize += kHash4Size; 215 hs += p->fixedHashSize; 216 } 217 218 { 219 UInt32 prevSize = p->hashSizeSum + p->numSons; 220 UInt32 newSize; 221 p->historySize = historySize; 222 p->hashSizeSum = hs; 223 p->cyclicBufferSize = newCyclicBufferSize; 224 p->numSons = (p->btMode ? newCyclicBufferSize * 2 : newCyclicBufferSize); 225 newSize = p->hashSizeSum + p->numSons; 226 if (p->hash != 0 && prevSize == newSize) 227 return 1; 228 MatchFinder_FreeThisClassMemory(p, alloc); 229 p->hash = AllocRefs(newSize, alloc); 230 if (p->hash != 0) 231 { 232 p->son = p->hash + p->hashSizeSum; 233 return 1; 234 } 235 } 236 } 237 MatchFinder_Free(p, alloc); 238 return 0; 239 } 240 241 static void MatchFinder_SetLimits(CMatchFinder *p) 242 { 243 UInt32 limit = kMaxValForNormalize - p->pos; 244 UInt32 limit2 = p->cyclicBufferSize - p->cyclicBufferPos; 245 if (limit2 < limit) 246 limit = limit2; 247 limit2 = p->streamPos - p->pos; 248 if (limit2 <= p->keepSizeAfter) 249 { 250 if (limit2 > 0) 251 limit2 = 1; 252 } 253 else 254 limit2 -= p->keepSizeAfter; 255 if (limit2 < limit) 256 limit = limit2; 257 { 258 UInt32 lenLimit = p->streamPos - p->pos; 259 if (lenLimit > p->matchMaxLen) 260 lenLimit = p->matchMaxLen; 261 p->lenLimit = lenLimit; 262 } 263 p->posLimit = p->pos + limit; 264 } 265 266 void MatchFinder_Init(CMatchFinder *p) 267 { 268 UInt32 i; 269 for (i = 0; i < p->hashSizeSum; i++) 270 p->hash[i] = kEmptyHashValue; 271 p->cyclicBufferPos = 0; 272 p->buffer = p->bufferBase; 273 p->pos = p->streamPos = p->cyclicBufferSize; 274 p->result = SZ_OK; 275 p->streamEndWasReached = 0; 276 MatchFinder_ReadBlock(p); 277 MatchFinder_SetLimits(p); 278 } 279 280 static UInt32 MatchFinder_GetSubValue(CMatchFinder *p) 281 { 282 return (p->pos - p->historySize - 1) & kNormalizeMask; 283 } 284 285 void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, UInt32 numItems) 286 { 287 UInt32 i; 288 for (i = 0; i < numItems; i++) 289 { 290 UInt32 value = items[i]; 291 if (value <= subValue) 292 value = kEmptyHashValue; 293 else 294 value -= subValue; 295 items[i] = value; 296 } 297 } 298 299 static void MatchFinder_Normalize(CMatchFinder *p) 300 { 301 UInt32 subValue = MatchFinder_GetSubValue(p); 302 MatchFinder_Normalize3(subValue, p->hash, p->hashSizeSum + p->numSons); 303 MatchFinder_ReduceOffsets(p, subValue); 304 } 305 306 static void MatchFinder_CheckLimits(CMatchFinder *p) 307 { 308 if (p->pos == kMaxValForNormalize) 309 MatchFinder_Normalize(p); 310 if (!p->streamEndWasReached && p->keepSizeAfter == p->streamPos - p->pos) 311 MatchFinder_CheckAndMoveAndRead(p); 312 if (p->cyclicBufferPos == p->cyclicBufferSize) 313 p->cyclicBufferPos = 0; 314 MatchFinder_SetLimits(p); 315 } 316 317 static UInt32 * Hc_GetMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, 318 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue, 319 UInt32 *distances, UInt32 maxLen) 320 { 321 son[_cyclicBufferPos] = curMatch; 322 for (;;) 323 { 324 UInt32 delta = pos - curMatch; 325 if (cutValue-- == 0 || delta >= _cyclicBufferSize) 326 return distances; 327 { 328 const Byte *pb = cur - delta; 329 curMatch = son[_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)]; 330 if (pb[maxLen] == cur[maxLen] && *pb == *cur) 331 { 332 UInt32 len = 0; 333 while (++len != lenLimit) 334 if (pb[len] != cur[len]) 335 break; 336 if (maxLen < len) 337 { 338 *distances++ = maxLen = len; 339 *distances++ = delta - 1; 340 if (len == lenLimit) 341 return distances; 342 } 343 } 344 } 345 } 346 } 347 348 UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, 349 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue, 350 UInt32 *distances, UInt32 maxLen) 351 { 352 CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1; 353 CLzRef *ptr1 = son + (_cyclicBufferPos << 1); 354 UInt32 len0 = 0, len1 = 0; 355 for (;;) 356 { 357 UInt32 delta = pos - curMatch; 358 if (cutValue-- == 0 || delta >= _cyclicBufferSize) 359 { 360 *ptr0 = *ptr1 = kEmptyHashValue; 361 return distances; 362 } 363 { 364 CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1); 365 const Byte *pb = cur - delta; 366 UInt32 len = (len0 < len1 ? len0 : len1); 367 if (pb[len] == cur[len]) 368 { 369 if (++len != lenLimit && pb[len] == cur[len]) 370 while (++len != lenLimit) 371 if (pb[len] != cur[len]) 372 break; 373 if (maxLen < len) 374 { 375 *distances++ = maxLen = len; 376 *distances++ = delta - 1; 377 if (len == lenLimit) 378 { 379 *ptr1 = pair[0]; 380 *ptr0 = pair[1]; 381 return distances; 382 } 383 } 384 } 385 if (pb[len] < cur[len]) 386 { 387 *ptr1 = curMatch; 388 ptr1 = pair + 1; 389 curMatch = *ptr1; 390 len1 = len; 391 } 392 else 393 { 394 *ptr0 = curMatch; 395 ptr0 = pair; 396 curMatch = *ptr0; 397 len0 = len; 398 } 399 } 400 } 401 } 402 403 static void SkipMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, 404 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue) 405 { 406 CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1; 407 CLzRef *ptr1 = son + (_cyclicBufferPos << 1); 408 UInt32 len0 = 0, len1 = 0; 409 for (;;) 410 { 411 UInt32 delta = pos - curMatch; 412 if (cutValue-- == 0 || delta >= _cyclicBufferSize) 413 { 414 *ptr0 = *ptr1 = kEmptyHashValue; 415 return; 416 } 417 { 418 CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1); 419 const Byte *pb = cur - delta; 420 UInt32 len = (len0 < len1 ? len0 : len1); 421 if (pb[len] == cur[len]) 422 { 423 while (++len != lenLimit) 424 if (pb[len] != cur[len]) 425 break; 426 { 427 if (len == lenLimit) 428 { 429 *ptr1 = pair[0]; 430 *ptr0 = pair[1]; 431 return; 432 } 433 } 434 } 435 if (pb[len] < cur[len]) 436 { 437 *ptr1 = curMatch; 438 ptr1 = pair + 1; 439 curMatch = *ptr1; 440 len1 = len; 441 } 442 else 443 { 444 *ptr0 = curMatch; 445 ptr0 = pair; 446 curMatch = *ptr0; 447 len0 = len; 448 } 449 } 450 } 451 } 452 453 #define MOVE_POS \ 454 ++p->cyclicBufferPos; \ 455 p->buffer++; \ 456 if (++p->pos == p->posLimit) MatchFinder_CheckLimits(p); 457 458 #define MOVE_POS_RET MOVE_POS return offset; 459 460 static void MatchFinder_MovePos(CMatchFinder *p) { MOVE_POS; } 461 462 #define GET_MATCHES_HEADER2(minLen, ret_op) \ 463 UInt32 lenLimit; UInt32 hashValue; const Byte *cur; UInt32 curMatch; \ 464 lenLimit = p->lenLimit; { if (lenLimit < minLen) { MatchFinder_MovePos(p); ret_op; }} \ 465 cur = p->buffer; 466 467 #define GET_MATCHES_HEADER(minLen) GET_MATCHES_HEADER2(minLen, return 0) 468 #define SKIP_HEADER(minLen) GET_MATCHES_HEADER2(minLen, continue) 469 470 #define MF_PARAMS(p) p->pos, p->buffer, p->son, p->cyclicBufferPos, p->cyclicBufferSize, p->cutValue 471 472 #define GET_MATCHES_FOOTER(offset, maxLen) \ 473 offset = (UInt32)(GetMatchesSpec1(lenLimit, curMatch, MF_PARAMS(p), \ 474 distances + offset, maxLen) - distances); MOVE_POS_RET; 475 476 #define SKIP_FOOTER \ 477 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); MOVE_POS; 478 479 static UInt32 Bt2_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 480 { 481 UInt32 offset; 482 GET_MATCHES_HEADER(2) 483 HASH2_CALC; 484 curMatch = p->hash[hashValue]; 485 p->hash[hashValue] = p->pos; 486 offset = 0; 487 GET_MATCHES_FOOTER(offset, 1) 488 } 489 490 UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 491 { 492 UInt32 offset; 493 GET_MATCHES_HEADER(3) 494 HASH_ZIP_CALC; 495 curMatch = p->hash[hashValue]; 496 p->hash[hashValue] = p->pos; 497 offset = 0; 498 GET_MATCHES_FOOTER(offset, 2) 499 } 500 501 static UInt32 Bt3_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 502 { 503 UInt32 hash2Value, delta2, maxLen, offset; 504 GET_MATCHES_HEADER(3) 505 506 HASH3_CALC; 507 508 delta2 = p->pos - p->hash[hash2Value]; 509 curMatch = p->hash[kFix3HashSize + hashValue]; 510 511 p->hash[hash2Value] = 512 p->hash[kFix3HashSize + hashValue] = p->pos; 513 514 515 maxLen = 2; 516 offset = 0; 517 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) 518 { 519 for (; maxLen != lenLimit; maxLen++) 520 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) 521 break; 522 distances[0] = maxLen; 523 distances[1] = delta2 - 1; 524 offset = 2; 525 if (maxLen == lenLimit) 526 { 527 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); 528 MOVE_POS_RET; 529 } 530 } 531 GET_MATCHES_FOOTER(offset, maxLen) 532 } 533 534 static UInt32 Bt4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 535 { 536 UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset; 537 GET_MATCHES_HEADER(4) 538 539 HASH4_CALC; 540 541 delta2 = p->pos - p->hash[ hash2Value]; 542 delta3 = p->pos - p->hash[kFix3HashSize + hash3Value]; 543 curMatch = p->hash[kFix4HashSize + hashValue]; 544 545 p->hash[ hash2Value] = 546 p->hash[kFix3HashSize + hash3Value] = 547 p->hash[kFix4HashSize + hashValue] = p->pos; 548 549 maxLen = 1; 550 offset = 0; 551 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) 552 { 553 distances[0] = maxLen = 2; 554 distances[1] = delta2 - 1; 555 offset = 2; 556 } 557 if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur) 558 { 559 maxLen = 3; 560 distances[offset + 1] = delta3 - 1; 561 offset += 2; 562 delta2 = delta3; 563 } 564 if (offset != 0) 565 { 566 for (; maxLen != lenLimit; maxLen++) 567 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) 568 break; 569 distances[offset - 2] = maxLen; 570 if (maxLen == lenLimit) 571 { 572 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); 573 MOVE_POS_RET; 574 } 575 } 576 if (maxLen < 3) 577 maxLen = 3; 578 GET_MATCHES_FOOTER(offset, maxLen) 579 } 580 581 static UInt32 Hc4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 582 { 583 UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset; 584 GET_MATCHES_HEADER(4) 585 586 HASH4_CALC; 587 588 delta2 = p->pos - p->hash[ hash2Value]; 589 delta3 = p->pos - p->hash[kFix3HashSize + hash3Value]; 590 curMatch = p->hash[kFix4HashSize + hashValue]; 591 592 p->hash[ hash2Value] = 593 p->hash[kFix3HashSize + hash3Value] = 594 p->hash[kFix4HashSize + hashValue] = p->pos; 595 596 maxLen = 1; 597 offset = 0; 598 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) 599 { 600 distances[0] = maxLen = 2; 601 distances[1] = delta2 - 1; 602 offset = 2; 603 } 604 if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur) 605 { 606 maxLen = 3; 607 distances[offset + 1] = delta3 - 1; 608 offset += 2; 609 delta2 = delta3; 610 } 611 if (offset != 0) 612 { 613 for (; maxLen != lenLimit; maxLen++) 614 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) 615 break; 616 distances[offset - 2] = maxLen; 617 if (maxLen == lenLimit) 618 { 619 p->son[p->cyclicBufferPos] = curMatch; 620 MOVE_POS_RET; 621 } 622 } 623 if (maxLen < 3) 624 maxLen = 3; 625 offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p), 626 distances + offset, maxLen) - (distances)); 627 MOVE_POS_RET 628 } 629 630 UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) 631 { 632 UInt32 offset; 633 GET_MATCHES_HEADER(3) 634 HASH_ZIP_CALC; 635 curMatch = p->hash[hashValue]; 636 p->hash[hashValue] = p->pos; 637 offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p), 638 distances, 2) - (distances)); 639 MOVE_POS_RET 640 } 641 642 static void Bt2_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 643 { 644 do 645 { 646 SKIP_HEADER(2) 647 HASH2_CALC; 648 curMatch = p->hash[hashValue]; 649 p->hash[hashValue] = p->pos; 650 SKIP_FOOTER 651 } 652 while (--num != 0); 653 } 654 655 void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 656 { 657 do 658 { 659 SKIP_HEADER(3) 660 HASH_ZIP_CALC; 661 curMatch = p->hash[hashValue]; 662 p->hash[hashValue] = p->pos; 663 SKIP_FOOTER 664 } 665 while (--num != 0); 666 } 667 668 static void Bt3_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 669 { 670 do 671 { 672 UInt32 hash2Value; 673 SKIP_HEADER(3) 674 HASH3_CALC; 675 curMatch = p->hash[kFix3HashSize + hashValue]; 676 p->hash[hash2Value] = 677 p->hash[kFix3HashSize + hashValue] = p->pos; 678 SKIP_FOOTER 679 } 680 while (--num != 0); 681 } 682 683 static void Bt4_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 684 { 685 do 686 { 687 UInt32 hash2Value, hash3Value; 688 SKIP_HEADER(4) 689 HASH4_CALC; 690 curMatch = p->hash[kFix4HashSize + hashValue]; 691 p->hash[ hash2Value] = 692 p->hash[kFix3HashSize + hash3Value] = p->pos; 693 p->hash[kFix4HashSize + hashValue] = p->pos; 694 SKIP_FOOTER 695 } 696 while (--num != 0); 697 } 698 699 static void Hc4_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 700 { 701 do 702 { 703 UInt32 hash2Value, hash3Value; 704 SKIP_HEADER(4) 705 HASH4_CALC; 706 curMatch = p->hash[kFix4HashSize + hashValue]; 707 p->hash[ hash2Value] = 708 p->hash[kFix3HashSize + hash3Value] = 709 p->hash[kFix4HashSize + hashValue] = p->pos; 710 p->son[p->cyclicBufferPos] = curMatch; 711 MOVE_POS 712 } 713 while (--num != 0); 714 } 715 716 void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num) 717 { 718 do 719 { 720 SKIP_HEADER(3) 721 HASH_ZIP_CALC; 722 curMatch = p->hash[hashValue]; 723 p->hash[hashValue] = p->pos; 724 p->son[p->cyclicBufferPos] = curMatch; 725 MOVE_POS 726 } 727 while (--num != 0); 728 } 729 730 void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder *vTable) 731 { 732 vTable->Init = (Mf_Init_Func)MatchFinder_Init; 733 vTable->GetIndexByte = (Mf_GetIndexByte_Func)MatchFinder_GetIndexByte; 734 vTable->GetNumAvailableBytes = (Mf_GetNumAvailableBytes_Func)MatchFinder_GetNumAvailableBytes; 735 vTable->GetPointerToCurrentPos = (Mf_GetPointerToCurrentPos_Func)MatchFinder_GetPointerToCurrentPos; 736 if (!p->btMode) 737 { 738 vTable->GetMatches = (Mf_GetMatches_Func)Hc4_MatchFinder_GetMatches; 739 vTable->Skip = (Mf_Skip_Func)Hc4_MatchFinder_Skip; 740 } 741 else if (p->numHashBytes == 2) 742 { 743 vTable->GetMatches = (Mf_GetMatches_Func)Bt2_MatchFinder_GetMatches; 744 vTable->Skip = (Mf_Skip_Func)Bt2_MatchFinder_Skip; 745 } 746 else if (p->numHashBytes == 3) 747 { 748 vTable->GetMatches = (Mf_GetMatches_Func)Bt3_MatchFinder_GetMatches; 749 vTable->Skip = (Mf_Skip_Func)Bt3_MatchFinder_Skip; 750 } 751 else 752 { 753 vTable->GetMatches = (Mf_GetMatches_Func)Bt4_MatchFinder_GetMatches; 754 vTable->Skip = (Mf_Skip_Func)Bt4_MatchFinder_Skip; 755 } 756 } 757