1 /* MatchFinder.c */

     2 /* Please call InitCrcTable before */

     3 

     4 #include <string.h>

     5 

     6 #include "MatchFinder.h"

     7 #include "LzHash.h"

     8 

     9 #include "../../7zCrc.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 void LzInWindow_Free(CMatchFinder *p, ISzAlloc *alloc)

    20 {

    21   if (!p->directInput)

    22   {

    23     alloc->Free(p->bufferBase);

    24     p->bufferBase = 0;

    25   }

    26 }

    27 

    28 /* keepSizeBefore + keepSizeAfter + keepSizeReserv must be < 4G) */

    29 

    30 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(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 void MatchFinder_ReadBlock(CMatchFinder *p)

    60 {

    61   if (p->streamEndWasReached || p->result != SZ_OK)

    62     return;

    63   for (;;)

    64   {

    65     Byte *dest = p->buffer + (p->streamPos - p->pos);

    66     UInt32 numReadBytes;

    67     UInt32 size = (UInt32)(p->bufferBase + p->blockSize - dest);

    68     if (size == 0)

    69       return;

    70     p->result = p->stream->Read(p->stream, dest, size, &numReadBytes);

    71     if (p->result != SZ_OK)

    72       return;

    73     if (numReadBytes == 0)

    74     {

    75       p->streamEndWasReached = 1;

    76       return;

    77     }

    78     p->streamPos += numReadBytes;

    79     if (p->streamPos - p->pos > p->keepSizeAfter)

    80       return;

    81   }

    82 }

    83 

    84 void MatchFinder_MoveBlock(CMatchFinder *p)

    85 {

    86   memmove(p->bufferBase, 

    87     p->buffer - p->keepSizeBefore, 

    88     p->streamPos - p->pos + p->keepSizeBefore);

    89   p->buffer = p->bufferBase + p->keepSizeBefore;

    90 }

    91 

    92 int MatchFinder_NeedMove(CMatchFinder *p)

    93 {

    94   /* if (p->streamEndWasReached) return 0; */

    95   return ((size_t)(p->bufferBase + p->blockSize - p->buffer) <= p->keepSizeAfter);

    96 }

    97 

    98 void MatchFinder_ReadIfRequired(CMatchFinder *p)

    99 {

   100   if (p->streamEndWasReached) 

   101     return;

   102   if (p->keepSizeAfter >= p->streamPos - p->pos)

   103     MatchFinder_ReadBlock(p);

   104 }

   105 

   106 void MatchFinder_CheckAndMoveAndRead(CMatchFinder *p)

   107 {

   108   if (MatchFinder_NeedMove(p))

   109     MatchFinder_MoveBlock(p);

   110   MatchFinder_ReadBlock(p);

   111 }

   112 

   113 void MatchFinder_SetDefaultSettings(CMatchFinder *p)

   114 {

   115   p->cutValue = 32;

   116   p->btMode = 1;

   117   p->numHashBytes = 4;

   118   /* p->skipModeBits = 0; */

   119   p->directInput = 0;

   120   p->bigHash = 0;

   121 }

   122 

   123 void MatchFinder_Construct(CMatchFinder *p)

   124 {

   125   p->bufferBase = 0;

   126   p->directInput = 0;

   127   p->hash = 0;

   128   MatchFinder_SetDefaultSettings(p);

   129 }

   130 

   131 void MatchFinder_FreeThisClassMemory(CMatchFinder *p, ISzAlloc *alloc)

   132 {

   133   alloc->Free(p->hash);

   134   p->hash = 0;

   135 }

   136 

   137 void MatchFinder_Free(CMatchFinder *p, ISzAlloc *alloc)

   138 {

   139   MatchFinder_FreeThisClassMemory(p, alloc);

   140   LzInWindow_Free(p, alloc);

   141 }

   142 

   143 CLzRef* AllocRefs(UInt32 num, ISzAlloc *alloc)

   144 {

   145   size_t sizeInBytes = (size_t)num * sizeof(CLzRef);

   146   if (sizeInBytes / sizeof(CLzRef) != num)

   147     return 0;

   148   return (CLzRef *)alloc->Alloc(sizeInBytes);

   149 }

   150 

   151 int MatchFinder_Create(CMatchFinder *p, UInt32 historySize, 

   152     UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter,

   153     ISzAlloc *alloc)

   154 {

   155   UInt32 sizeReserv;

   156   if (historySize > kMaxHistorySize)

   157   {

   158     MatchFinder_Free(p, alloc);

   159     return 0;

   160   }

   161   sizeReserv = historySize >> 1;

   162   if (historySize > ((UInt32)2 << 30))

   163     sizeReserv = historySize >> 2;

   164   sizeReserv += (keepAddBufferBefore + matchMaxLen + keepAddBufferAfter) / 2 + (1 << 19);

   165 

   166   p->keepSizeBefore = historySize + keepAddBufferBefore + 1; 

   167   p->keepSizeAfter = matchMaxLen + keepAddBufferAfter;

   168   /* we need one additional byte, since we use MoveBlock after pos++ and before dictionary using */

   169   if (LzInWindow_Create(p, sizeReserv, alloc))

   170   {

   171     UInt32 newCyclicBufferSize = (historySize /* >> p->skipModeBits */) + 1;

   172     UInt32 hs;

   173     p->matchMaxLen = matchMaxLen;

   174     {

   175       p->fixedHashSize = 0;

   176       if (p->numHashBytes == 2)

   177         hs = (1 << 16) - 1;

   178       else

   179       {

   180         hs = historySize - 1;

   181         hs |= (hs >> 1);

   182         hs |= (hs >> 2);

   183         hs |= (hs >> 4);

   184         hs |= (hs >> 8);

   185         hs >>= 1;

   186         /* hs >>= p->skipModeBits; */

   187         hs |= 0xFFFF; /* don't change it! It's required for Deflate */

   188         if (hs > (1 << 24))

   189         {

   190           if (p->numHashBytes == 3)

   191             hs = (1 << 24) - 1;

   192           else

   193             hs >>= 1;

   194         }

   195       }

   196       p->hashMask = hs;

   197       hs++;

   198       if (p->numHashBytes > 2) p->fixedHashSize += kHash2Size;

   199       if (p->numHashBytes > 3) p->fixedHashSize += kHash3Size;

   200       if (p->numHashBytes > 4) p->fixedHashSize += kHash4Size;

   201       hs += p->fixedHashSize;

   202     }

   203 

   204     {

   205       UInt32 prevSize = p->hashSizeSum + p->numSons;

   206       UInt32 newSize;

   207       p->historySize = historySize;

   208       p->hashSizeSum = hs;

   209       p->cyclicBufferSize = newCyclicBufferSize;

   210       p->numSons = (p->btMode ? newCyclicBufferSize * 2 : newCyclicBufferSize);

   211       newSize = p->hashSizeSum + p->numSons;

   212       if (p->hash != 0 && prevSize == newSize)

   213         return 1;

   214       MatchFinder_FreeThisClassMemory(p, alloc);

   215       p->hash = AllocRefs(newSize, alloc);

   216       if (p->hash != 0)

   217       {

   218         p->son = p->hash + p->hashSizeSum;

   219         return 1;

   220       }

   221     }

   222   }

   223   MatchFinder_Free(p, alloc);

   224   return 0;

   225 }

   226 

   227 void MatchFinder_SetLimits(CMatchFinder *p)

   228 {

   229   UInt32 limit = kMaxValForNormalize - p->pos;

   230   UInt32 limit2 = p->cyclicBufferSize - p->cyclicBufferPos;

   231   if (limit2 < limit) 

   232     limit = limit2;

   233   limit2 = p->streamPos - p->pos;

   234   if (limit2 <= p->keepSizeAfter)

   235   {

   236     if (limit2 > 0)

   237       limit2 = 1;

   238   }

   239   else

   240     limit2 -= p->keepSizeAfter;

   241   if (limit2 < limit) 

   242     limit = limit2;

   243   {

   244     UInt32 lenLimit = p->streamPos - p->pos;

   245     if (lenLimit > p->matchMaxLen)

   246       lenLimit = p->matchMaxLen;

   247     p->lenLimit = lenLimit;

   248   }

   249   p->posLimit = p->pos + limit;

   250 }

   251 

   252 void MatchFinder_Init(CMatchFinder *p)

   253 {

   254   UInt32 i;

   255   for(i = 0; i < p->hashSizeSum; i++)

   256     p->hash[i] = kEmptyHashValue;

   257   p->cyclicBufferPos = 0;

   258   p->buffer = p->bufferBase;

   259   p->pos = p->streamPos = p->cyclicBufferSize;

   260   p->result = SZ_OK;

   261   p->streamEndWasReached = 0;

   262   MatchFinder_ReadBlock(p);

   263   MatchFinder_SetLimits(p);

   264 }

   265 

   266 UInt32 MatchFinder_GetSubValue(CMatchFinder *p) 

   267 { 

   268   return (p->pos - p->historySize - 1) & kNormalizeMask; 

   269 }

   270 

   271 void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, UInt32 numItems)

   272 {

   273   UInt32 i;

   274   for (i = 0; i < numItems; i++)

   275   {

   276     UInt32 value = items[i];

   277     if (value <= subValue)

   278       value = kEmptyHashValue;

   279     else

   280       value -= subValue;

   281     items[i] = value;

   282   }

   283 }

   284 

   285 void MatchFinder_Normalize(CMatchFinder *p)

   286 {

   287   UInt32 subValue = MatchFinder_GetSubValue(p);

   288   MatchFinder_Normalize3(subValue, p->hash, p->hashSizeSum + p->numSons);

   289   MatchFinder_ReduceOffsets(p, subValue);

   290 }

   291 

   292 void MatchFinder_CheckLimits(CMatchFinder *p)

   293 {

   294   if (p->pos == kMaxValForNormalize)

   295     MatchFinder_Normalize(p);

   296   if (!p->streamEndWasReached && p->keepSizeAfter == p->streamPos - p->pos)

   297     MatchFinder_CheckAndMoveAndRead(p);

   298   if (p->cyclicBufferPos == p->cyclicBufferSize)

   299     p->cyclicBufferPos = 0;

   300   MatchFinder_SetLimits(p);

   301 }

   302 

   303 UInt32 * Hc_GetMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, 

   304     UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue, 

   305     UInt32 *distances, UInt32 maxLen)

   306 {

   307   son[_cyclicBufferPos] = curMatch;

   308   for (;;)

   309   {

   310     UInt32 delta = pos - curMatch;

   311     if (cutValue-- == 0 || delta >= _cyclicBufferSize)

   312       return distances;

   313     {

   314       const Byte *pb = cur - delta;

   315       curMatch = son[_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)];

   316       if (pb[maxLen] == cur[maxLen] && *pb == *cur)

   317       {

   318         UInt32 len = 0;

   319         while(++len != lenLimit)

   320           if (pb[len] != cur[len])

   321             break;

   322         if (maxLen < len)

   323         {

   324           *distances++ = maxLen = len;

   325           *distances++ = delta - 1;

   326           if (len == lenLimit)

   327             return distances;

   328         }

   329       }

   330     }

   331   }

   332 }

   333 

   334 UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, 

   335     UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue, 

   336     UInt32 *distances, UInt32 maxLen)

   337 {

   338   CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;

   339   CLzRef *ptr1 = son + (_cyclicBufferPos << 1);

   340   UInt32 len0 = 0, len1 = 0;

   341   for (;;)

   342   {

   343     UInt32 delta = pos - curMatch;

   344     if (cutValue-- == 0 || delta >= _cyclicBufferSize)

   345     {

   346       *ptr0 = *ptr1 = kEmptyHashValue;

   347       return distances;

   348     }

   349     {

   350       CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);

   351       const Byte *pb = cur - delta;

   352       UInt32 len = (len0 < len1 ? len0 : len1);

   353       if (pb[len] == cur[len])

   354       {

   355         if (++len != lenLimit && pb[len] == cur[len])

   356           while(++len != lenLimit)

   357             if (pb[len] != cur[len])

   358               break;

   359         if (maxLen < len)

   360         {

   361           *distances++ = maxLen = len;

   362           *distances++ = delta - 1;

   363           if (len == lenLimit)

   364           {

   365             *ptr1 = pair[0];

   366             *ptr0 = pair[1];

   367             return distances;

   368           }

   369         }

   370       }

   371       if (pb[len] < cur[len])

   372       {

   373         *ptr1 = curMatch;

   374         ptr1 = pair + 1;

   375         curMatch = *ptr1;

   376         len1 = len;

   377       }

   378       else

   379       {

   380         *ptr0 = curMatch;

   381         ptr0 = pair;

   382         curMatch = *ptr0;

   383         len0 = len;

   384       }

   385     }

   386   }

   387 }

   388 

   389 void SkipMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, 

   390     UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue)

   391 {

   392   CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;

   393   CLzRef *ptr1 = son + (_cyclicBufferPos << 1);

   394   UInt32 len0 = 0, len1 = 0;

   395   for (;;)

   396   {

   397     UInt32 delta = pos - curMatch;

   398     if (cutValue-- == 0 || delta >= _cyclicBufferSize)

   399     {

   400       *ptr0 = *ptr1 = kEmptyHashValue;

   401       return;

   402     }

   403     {

   404       CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);

   405       const Byte *pb = cur - delta;

   406       UInt32 len = (len0 < len1 ? len0 : len1);

   407       if (pb[len] == cur[len])

   408       {

   409         while(++len != lenLimit)

   410           if (pb[len] != cur[len])

   411             break;

   412         {

   413           if (len == lenLimit)

   414           {

   415             *ptr1 = pair[0];

   416             *ptr0 = pair[1];

   417             return;

   418           }

   419         }

   420       }

   421       if (pb[len] < cur[len])

   422       {

   423         *ptr1 = curMatch;

   424         ptr1 = pair + 1;

   425         curMatch = *ptr1;

   426         len1 = len;

   427       }

   428       else

   429       {

   430         *ptr0 = curMatch;

   431         ptr0 = pair;

   432         curMatch = *ptr0;

   433         len0 = len;

   434       }

   435     }

   436   }

   437 }

   438 

   439 #define MOVE_POS \

   440   ++p->cyclicBufferPos; \

   441   p->buffer++; \

   442   if (++p->pos == p->posLimit) MatchFinder_CheckLimits(p);

   443 

   444 #define MOVE_POS_RET MOVE_POS return offset;

   445 

   446 void MatchFinder_MovePos(CMatchFinder *p) { MOVE_POS; }

   447 

   448 #define GET_MATCHES_HEADER2(minLen, ret_op) \

   449   UInt32 lenLimit; UInt32 hashValue; const Byte *cur; UInt32 curMatch; \

   450   lenLimit = p->lenLimit; { if (lenLimit < minLen) { MatchFinder_MovePos(p); ret_op; }} \

   451   cur = p->buffer;

   452 

   453 #define GET_MATCHES_HEADER(minLen) GET_MATCHES_HEADER2(minLen, return 0)

   454 #define SKIP_HEADER(minLen)        GET_MATCHES_HEADER2(minLen, continue)

   455 

   456 #define MF_PARAMS(p) p->pos, p->buffer, p->son, p->cyclicBufferPos, p->cyclicBufferSize, p->cutValue

   457 

   458 #define GET_MATCHES_FOOTER(offset, maxLen) \

   459   offset = (UInt32)(GetMatchesSpec1(lenLimit, curMatch, MF_PARAMS(p), \

   460   distances + offset, maxLen) - distances); MOVE_POS_RET;

   461 

   462 #define SKIP_FOOTER \

   463   SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); MOVE_POS;

   464 

   465 UInt32 Bt2_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)

   466 {

   467   UInt32 offset;

   468   GET_MATCHES_HEADER(2)

   469   HASH2_CALC;

   470   curMatch = p->hash[hashValue];

   471   p->hash[hashValue] = p->pos;

   472   offset = 0;

   473   GET_MATCHES_FOOTER(offset, 1)

   474 }

   475 

   476 UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)

   477 {

   478   UInt32 offset;

   479   GET_MATCHES_HEADER(3)

   480   HASH_ZIP_CALC;

   481   curMatch = p->hash[hashValue];

   482   p->hash[hashValue] = p->pos;

   483   offset = 0;

   484   GET_MATCHES_FOOTER(offset, 2)

   485 }

   486 

   487 UInt32 Bt3_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)

   488 {

   489   UInt32 hash2Value, delta2, maxLen, offset;

   490   GET_MATCHES_HEADER(3)

   491 

   492   HASH3_CALC;

   493 

   494   delta2 = p->pos - p->hash[hash2Value];

   495   curMatch = p->hash[kFix3HashSize + hashValue];

   496   

   497   p->hash[hash2Value] = 

   498   p->hash[kFix3HashSize + hashValue] = p->pos;

   499 

   500 

   501   maxLen = 2;

   502   offset = 0;

   503   if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)

   504   {

   505     for (; maxLen != lenLimit; maxLen++)

   506       if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])

   507         break;

   508     distances[0] = maxLen;

   509     distances[1] = delta2 - 1;

   510     offset = 2;

   511     if (maxLen == lenLimit)

   512     {

   513       SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p));

   514       MOVE_POS_RET; 

   515     }

   516   }

   517   GET_MATCHES_FOOTER(offset, maxLen)

   518 }

   519 

   520 UInt32 Bt4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)

   521 {

   522   UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset;

   523   GET_MATCHES_HEADER(4)

   524 

   525   HASH4_CALC;

   526 

   527   delta2 = p->pos - p->hash[                hash2Value];

   528   delta3 = p->pos - p->hash[kFix3HashSize + hash3Value];

   529   curMatch = p->hash[kFix4HashSize + hashValue];

   530   

   531   p->hash[                hash2Value] =

   532   p->hash[kFix3HashSize + hash3Value] =

   533   p->hash[kFix4HashSize + hashValue] = p->pos;

   534 

   535   maxLen = 1;

   536   offset = 0;

   537   if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)

   538   {

   539     distances[0] = maxLen = 2;

   540     distances[1] = delta2 - 1;

   541     offset = 2;

   542   }

   543   if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur)

   544   {

   545     maxLen = 3;

   546     distances[offset + 1] = delta3 - 1;

   547     offset += 2;

   548     delta2 = delta3;

   549   }

   550   if (offset != 0)

   551   {

   552     for (; maxLen != lenLimit; maxLen++)

   553       if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])

   554         break;

   555     distances[offset - 2] = maxLen;

   556     if (maxLen == lenLimit)

   557     {

   558       SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p));

   559       MOVE_POS_RET; 

   560     }

   561   }

   562   if (maxLen < 3)

   563     maxLen = 3;

   564   GET_MATCHES_FOOTER(offset, maxLen)

   565 }

   566 

   567 UInt32 Hc4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)

   568 {

   569   UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset;

   570   GET_MATCHES_HEADER(4)

   571 

   572   HASH4_CALC;

   573 

   574   delta2 = p->pos - p->hash[                hash2Value];

   575   delta3 = p->pos - p->hash[kFix3HashSize + hash3Value];

   576   curMatch = p->hash[kFix4HashSize + hashValue];

   577 

   578   p->hash[                hash2Value] =

   579   p->hash[kFix3HashSize + hash3Value] =

   580   p->hash[kFix4HashSize + hashValue] = p->pos;

   581 

   582   maxLen = 1;

   583   offset = 0;

   584   if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)

   585   {

   586     distances[0] = maxLen = 2;

   587     distances[1] = delta2 - 1;

   588     offset = 2;

   589   }

   590   if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur)

   591   {

   592     maxLen = 3;

   593     distances[offset + 1] = delta3 - 1;

   594     offset += 2;

   595     delta2 = delta3;

   596   }

   597   if (offset != 0)

   598   {

   599     for (; maxLen != lenLimit; maxLen++)

   600       if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])

   601         break;

   602     distances[offset - 2] = maxLen;

   603     if (maxLen == lenLimit)

   604     {

   605       p->son[p->cyclicBufferPos] = curMatch;

   606       MOVE_POS_RET; 

   607     }

   608   }

   609   if (maxLen < 3)

   610     maxLen = 3;

   611   offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p),

   612     distances + offset, maxLen) - (distances));

   613   MOVE_POS_RET

   614 }

   615 

   616 UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)

   617 {

   618   UInt32 offset;

   619   GET_MATCHES_HEADER(3)

   620   HASH_ZIP_CALC;

   621   curMatch = p->hash[hashValue];

   622   p->hash[hashValue] = p->pos;

   623   offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p),

   624     distances, 2) - (distances));

   625   MOVE_POS_RET

   626 }

   627 

   628 void Bt2_MatchFinder_Skip(CMatchFinder *p, UInt32 num)

   629 {

   630   do

   631   {

   632     SKIP_HEADER(2) 

   633     HASH2_CALC;

   634     curMatch = p->hash[hashValue];

   635     p->hash[hashValue] = p->pos;

   636     SKIP_FOOTER

   637   }

   638   while (--num != 0);

   639 }

   640 

   641 void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num)

   642 {

   643   do

   644   {

   645     SKIP_HEADER(3)

   646     HASH_ZIP_CALC;

   647     curMatch = p->hash[hashValue];

   648     p->hash[hashValue] = p->pos;

   649     SKIP_FOOTER

   650   }

   651   while (--num != 0);

   652 }

   653 

   654 void Bt3_MatchFinder_Skip(CMatchFinder *p, UInt32 num)

   655 {

   656   do

   657   {

   658     UInt32 hash2Value;

   659     SKIP_HEADER(3)

   660     HASH3_CALC;

   661     curMatch = p->hash[kFix3HashSize + hashValue];

   662     p->hash[hash2Value] =

   663     p->hash[kFix3HashSize + hashValue] = p->pos;

   664     SKIP_FOOTER

   665   }

   666   while (--num != 0);

   667 }

   668 

   669 void Bt4_MatchFinder_Skip(CMatchFinder *p, UInt32 num)

   670 {

   671   do

   672   {

   673     UInt32 hash2Value, hash3Value;

   674     SKIP_HEADER(4) 

   675     HASH4_CALC;

   676     curMatch = p->hash[kFix4HashSize + hashValue];

   677     p->hash[                hash2Value] =

   678     p->hash[kFix3HashSize + hash3Value] = p->pos;

   679     p->hash[kFix4HashSize + hashValue] = p->pos;

   680     SKIP_FOOTER

   681   }

   682   while (--num != 0);

   683 }

   684 

   685 void Hc4_MatchFinder_Skip(CMatchFinder *p, UInt32 num)

   686 {

   687   do

   688   {

   689     UInt32 hash2Value, hash3Value;

   690     SKIP_HEADER(4)

   691     HASH4_CALC;

   692     curMatch = p->hash[kFix4HashSize + hashValue];

   693     p->hash[                hash2Value] =

   694     p->hash[kFix3HashSize + hash3Value] =

   695     p->hash[kFix4HashSize + hashValue] = p->pos;

   696     p->son[p->cyclicBufferPos] = curMatch;

   697     MOVE_POS

   698   }

   699   while (--num != 0);

   700 }

   701 

   702 void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num)

   703 {

   704   do

   705   {

   706     SKIP_HEADER(3)

   707     HASH_ZIP_CALC;

   708     curMatch = p->hash[hashValue];

   709     p->hash[hashValue] = p->pos;

   710     p->son[p->cyclicBufferPos] = curMatch;

   711     MOVE_POS

   712   }

   713   while (--num != 0);

   714 }

   715 

   716 void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder *vTable)

   717 {

   718   vTable->Init = (Mf_Init_Func)MatchFinder_Init;

   719   vTable->GetIndexByte = (Mf_GetIndexByte_Func)MatchFinder_GetIndexByte;

   720   vTable->GetNumAvailableBytes = (Mf_GetNumAvailableBytes_Func)MatchFinder_GetNumAvailableBytes;

   721   vTable->GetPointerToCurrentPos = (Mf_GetPointerToCurrentPos_Func)MatchFinder_GetPointerToCurrentPos;

   722   if (!p->btMode)

   723   {

   724     vTable->GetMatches = (Mf_GetMatches_Func)Hc4_MatchFinder_GetMatches;

   725     vTable->Skip = (Mf_Skip_Func)Hc4_MatchFinder_Skip;

   726   }

   727   else if (p->numHashBytes == 2)

   728   {

   729     vTable->GetMatches = (Mf_GetMatches_Func)Bt2_MatchFinder_GetMatches;

   730     vTable->Skip = (Mf_Skip_Func)Bt2_MatchFinder_Skip;

   731   }

   732   else if (p->numHashBytes == 3)

   733   {

   734     vTable->GetMatches = (Mf_GetMatches_Func)Bt3_MatchFinder_GetMatches;

   735     vTable->Skip = (Mf_Skip_Func)Bt3_MatchFinder_Skip;

   736   }

   737   else

   738   {

   739     vTable->GetMatches = (Mf_GetMatches_Func)Bt4_MatchFinder_GetMatches;

   740     vTable->Skip = (Mf_Skip_Func)Bt4_MatchFinder_Skip;

   741   }

   742 }