release/src-rt/tools/misc/lzma_src/C/LzFind.c

   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 }