/* LzFindMt.c -- multithreaded Match finder for LZ algorithms

 2008-10-04 : Igor Pavlov : Public domain */

 

 #include "LzHash.h"

 

 #include "LzFindMt.h"

 

 void MtSync_Construct(CMtSync *p)

 {

   p->wasCreated = False;

   p->csWasInitialized = False;

   p->csWasEntered = False;

   Thread_Construct(&p->thread);

   Event_Construct(&p->canStart);

   Event_Construct(&p->wasStarted);

   Event_Construct(&p->wasStopped);

   Semaphore_Construct(&p->freeSemaphore);

   Semaphore_Construct(&p->filledSemaphore);

 }

 

 void MtSync_GetNextBlock(CMtSync *p)

 {

   if (p->needStart)

   {

     p->numProcessedBlocks = 1;

     p->needStart = False;

     p->stopWriting = False;

     p->exit = False;

     Event_Reset(&p->wasStarted);

     Event_Reset(&p->wasStopped);

 

     Event_Set(&p->canStart);

     Event_Wait(&p->wasStarted);

   }

   else

   {

     CriticalSection_Leave(&p->cs);

     p->csWasEntered = False;

     p->numProcessedBlocks++;

     Semaphore_Release1(&p->freeSemaphore);

   }

   Semaphore_Wait(&p->filledSemaphore);

   CriticalSection_Enter(&p->cs);

   p->csWasEntered = True;

 }

 

 /* MtSync_StopWriting must be called if Writing was started */

 

 void MtSync_StopWriting(CMtSync *p)

 {

   UInt32 myNumBlocks = p->numProcessedBlocks;

   if (!Thread_WasCreated(&p->thread) || p->needStart)

     return;

   p->stopWriting = True;

   if (p->csWasEntered)

   {

     CriticalSection_Leave(&p->cs);

     p->csWasEntered = False;

   }

   Semaphore_Release1(&p->freeSemaphore);

  

   Event_Wait(&p->wasStopped);

 

   while (myNumBlocks++ != p->numProcessedBlocks)

   {

     Semaphore_Wait(&p->filledSemaphore);

     Semaphore_Release1(&p->freeSemaphore);

   }

   p->needStart = True;

 }

 

 void MtSync_Destruct(CMtSync *p)

 {

   if (Thread_WasCreated(&p->thread))

   {

     MtSync_StopWriting(p);

     p->exit = True;

     if (p->needStart)

       Event_Set(&p->canStart);

     Thread_Wait(&p->thread);

     Thread_Close(&p->thread);

   }

   if (p->csWasInitialized)

   {

     CriticalSection_Delete(&p->cs);

     p->csWasInitialized = False;

   }

 

   Event_Close(&p->canStart);

   Event_Close(&p->wasStarted);

   Event_Close(&p->wasStopped);

   Semaphore_Close(&p->freeSemaphore);

   Semaphore_Close(&p->filledSemaphore);

 

   p->wasCreated = False;

 }

 

 #define RINOK_THREAD(x) { if ((x) != 0) return SZ_ERROR_THREAD; }

 

 static SRes MtSync_Create2(CMtSync *p, unsigned (MY_STD_CALL *startAddress)(void *), void *obj, UInt32 numBlocks)

 {

   if (p->wasCreated)

     return SZ_OK;

 

   RINOK_THREAD(CriticalSection_Init(&p->cs));

   p->csWasInitialized = True;

 

   RINOK_THREAD(AutoResetEvent_CreateNotSignaled(&p->canStart));

   RINOK_THREAD(AutoResetEvent_CreateNotSignaled(&p->wasStarted));

   RINOK_THREAD(AutoResetEvent_CreateNotSignaled(&p->wasStopped));

   

   RINOK_THREAD(Semaphore_Create(&p->freeSemaphore, numBlocks, numBlocks));

   RINOK_THREAD(Semaphore_Create(&p->filledSemaphore, 0, numBlocks));

 

   p->needStart = True;

   

   RINOK_THREAD(Thread_Create(&p->thread, startAddress, obj));

   p->wasCreated = True;

   return SZ_OK;

 }

 

 static SRes MtSync_Create(CMtSync *p, unsigned (MY_STD_CALL *startAddress)(void *), void *obj, UInt32 numBlocks)

 {

   SRes res = MtSync_Create2(p, startAddress, obj, numBlocks);

   if (res != SZ_OK)

     MtSync_Destruct(p);

   return res;

 }

 

 void MtSync_Init(CMtSync *p) { p->needStart = True; }

 

 #define kMtMaxValForNormalize 0xFFFFFFFF

 

 #define DEF_GetHeads2(name, v, action) \

 static void GetHeads ## name(const Byte *p, UInt32 pos, \

 UInt32 *hash, UInt32 hashMask, UInt32 *heads, UInt32 numHeads, const UInt32 *crc) \

 { action; for (; numHeads != 0; numHeads--) { \

 const UInt32 value = (v); p++; *heads++ = pos - hash[value]; hash[value] = pos++;  } }

 

 #define DEF_GetHeads(name, v) DEF_GetHeads2(name, v, ;)

 

 DEF_GetHeads2(2,  (p[0] | ((UInt32)p[1] << 8)), hashMask = hashMask; crc = crc; )

 DEF_GetHeads(3,  (crc[p[0]] ^ p[1] ^ ((UInt32)p[2] << 8)) & hashMask)

 DEF_GetHeads(4,  (crc[p[0]] ^ p[1] ^ ((UInt32)p[2] << 8) ^ (crc[p[3]] << 5)) & hashMask)

 DEF_GetHeads(4b, (crc[p[0]] ^ p[1] ^ ((UInt32)p[2] << 8) ^ ((UInt32)p[3] << 16)) & hashMask)

 DEF_GetHeads(5,  (crc[p[0]] ^ p[1] ^ ((UInt32)p[2] << 8) ^ (crc[p[3]] << 5) ^ (crc[p[4]] << 3)) & hashMask)

 

 void HashThreadFunc(CMatchFinderMt *mt)

 {

   CMtSync *p = &mt->hashSync;

   for (;;)

   {

     UInt32 numProcessedBlocks = 0;

     Event_Wait(&p->canStart);

     Event_Set(&p->wasStarted);

     for (;;)

     {

       if (p->exit)

         return;

       if (p->stopWriting)

       {

         p->numProcessedBlocks = numProcessedBlocks;

         Event_Set(&p->wasStopped);

         break;

       }

 

       {

         CMatchFinder *mf = mt->MatchFinder;

         if (MatchFinder_NeedMove(mf))

         {

           CriticalSection_Enter(&mt->btSync.cs);

           CriticalSection_Enter(&mt->hashSync.cs);

           {

             const Byte *beforePtr = MatchFinder_GetPointerToCurrentPos(mf);

             const Byte *afterPtr;

             MatchFinder_MoveBlock(mf);

             afterPtr = MatchFinder_GetPointerToCurrentPos(mf);

             mt->pointerToCurPos -= beforePtr - afterPtr;

             mt->buffer -= beforePtr - afterPtr;

           }

           CriticalSection_Leave(&mt->btSync.cs);

           CriticalSection_Leave(&mt->hashSync.cs);

           continue;

         }

 

         Semaphore_Wait(&p->freeSemaphore);

 

         MatchFinder_ReadIfRequired(mf);

         if (mf->pos > (kMtMaxValForNormalize - kMtHashBlockSize))

         {

           UInt32 subValue = (mf->pos - mf->historySize - 1);

           MatchFinder_ReduceOffsets(mf, subValue);

           MatchFinder_Normalize3(subValue, mf->hash + mf->fixedHashSize, mf->hashMask + 1);

         }

         {

           UInt32 *heads = mt->hashBuf + ((numProcessedBlocks++) & kMtHashNumBlocksMask) * kMtHashBlockSize;

           UInt32 num = mf->streamPos - mf->pos;

           heads[0] = 2;

           heads[1] = num;

           if (num >= mf->numHashBytes)

           {

             num = num - mf->numHashBytes + 1;

             if (num > kMtHashBlockSize - 2)

               num = kMtHashBlockSize - 2;

             mt->GetHeadsFunc(mf->buffer, mf->pos, mf->hash + mf->fixedHashSize, mf->hashMask, heads + 2, num, mf->crc);

             heads[0] += num;

           }

           mf->pos += num;

           mf->buffer += num;

         }

       }

 

       Semaphore_Release1(&p->filledSemaphore);

     }

   }

 }

 

 void MatchFinderMt_GetNextBlock_Hash(CMatchFinderMt *p)

 {

   MtSync_GetNextBlock(&p->hashSync);

   p->hashBufPosLimit = p->hashBufPos = ((p->hashSync.numProcessedBlocks - 1) & kMtHashNumBlocksMask) * kMtHashBlockSize;

   p->hashBufPosLimit += p->hashBuf[p->hashBufPos++];

   p->hashNumAvail = p->hashBuf[p->hashBufPos++];

 }

 

 #define kEmptyHashValue 0

 

 /* #define MFMT_GM_INLINE */

 

 #ifdef MFMT_GM_INLINE

 

 #define NO_INLINE MY_FAST_CALL

 

 Int32 NO_INLINE GetMatchesSpecN(UInt32 lenLimit, UInt32 pos, const Byte *cur, CLzRef *son,

     UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 _cutValue,

     UInt32 *_distances, UInt32 _maxLen, const UInt32 *hash, Int32 limit, UInt32 size, UInt32 *posRes)

 {

   do

   {

   UInt32 *distances = _distances + 1;

   UInt32 curMatch = pos - *hash++;

 

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

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

   UInt32 len0 = 0, len1 = 0;

   UInt32 cutValue = _cutValue;

   UInt32 maxLen = _maxLen;

   for (;;)

   {

     UInt32 delta = pos - curMatch;

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

     {

       *ptr0 = *ptr1 = kEmptyHashValue;

       break;

     }

     {

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

       const Byte *pb = cur - delta;

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

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

       {

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

           while (++len != lenLimit)

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

               break;

         if (maxLen < len)

         {

           *distances++ = maxLen = len;

           *distances++ = delta - 1;

           if (len == lenLimit)

           {

             *ptr1 = pair[0];

             *ptr0 = pair[1];

             break;

           }

         }

       }

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

       {

         *ptr1 = curMatch;

         ptr1 = pair + 1;

         curMatch = *ptr1;

         len1 = len;

       }

       else

       {

         *ptr0 = curMatch;

         ptr0 = pair;

         curMatch = *ptr0;

         len0 = len;

       }

     }

   }

   pos++;

   _cyclicBufferPos++;

   cur++;

   {

     UInt32 num = (UInt32)(distances - _distances);

     *_distances = num - 1;

     _distances += num;

     limit -= num;

   }

   }

   while (limit > 0 && --size != 0);

   *posRes = pos;

   return limit;

 }

 

 #endif

 

 void BtGetMatches(CMatchFinderMt *p, UInt32 *distances)

 {

   UInt32 numProcessed = 0;

   UInt32 curPos = 2;

   UInt32 limit = kMtBtBlockSize - (p->matchMaxLen * 2);

   distances[1] = p->hashNumAvail;

   while (curPos < limit)

   {

     if (p->hashBufPos == p->hashBufPosLimit)

     {

       MatchFinderMt_GetNextBlock_Hash(p);

       distances[1] = numProcessed + p->hashNumAvail;

       if (p->hashNumAvail >= p->numHashBytes)

         continue;

       for (; p->hashNumAvail != 0; p->hashNumAvail--)

         distances[curPos++] = 0;

       break;

     }

     {

       UInt32 size = p->hashBufPosLimit - p->hashBufPos;

       UInt32 lenLimit = p->matchMaxLen;

       UInt32 pos = p->pos;

       UInt32 cyclicBufferPos = p->cyclicBufferPos;

       if (lenLimit >= p->hashNumAvail)

         lenLimit = p->hashNumAvail;

       {

         UInt32 size2 = p->hashNumAvail - lenLimit + 1;

         if (size2 < size)

           size = size2;

         size2 = p->cyclicBufferSize - cyclicBufferPos;

         if (size2 < size)

           size = size2;

       }

       #ifndef MFMT_GM_INLINE

       while (curPos < limit && size-- != 0)

       {

         UInt32 *startDistances = distances + curPos;

         UInt32 num = (UInt32)(GetMatchesSpec1(lenLimit, pos - p->hashBuf[p->hashBufPos++],

           pos, p->buffer, p->son, cyclicBufferPos, p->cyclicBufferSize, p->cutValue,

           startDistances + 1, p->numHashBytes - 1) - startDistances);

         *startDistances = num - 1;

         curPos += num;

         cyclicBufferPos++;

         pos++;

         p->buffer++;

       }

       #else

       {

         UInt32 posRes;

         curPos = limit - GetMatchesSpecN(lenLimit, pos, p->buffer, p->son, cyclicBufferPos, p->cyclicBufferSize, p->cutValue,

           distances + curPos, p->numHashBytes - 1, p->hashBuf + p->hashBufPos, (Int32)(limit - curPos) , size, &posRes);

         p->hashBufPos += posRes - pos;

         cyclicBufferPos += posRes - pos;

         p->buffer += posRes - pos;

         pos = posRes;

       }

       #endif

 

       numProcessed += pos - p->pos;

       p->hashNumAvail -= pos - p->pos;

       p->pos = pos;

       if (cyclicBufferPos == p->cyclicBufferSize)

         cyclicBufferPos = 0;

       p->cyclicBufferPos = cyclicBufferPos;

     }

   }

   distances[0] = curPos;

 }

 

 void BtFillBlock(CMatchFinderMt *p, UInt32 globalBlockIndex)

 {

   CMtSync *sync = &p->hashSync;

   if (!sync->needStart)

   {

     CriticalSection_Enter(&sync->cs);

     sync->csWasEntered = True;

   }

   

   BtGetMatches(p, p->btBuf + (globalBlockIndex & kMtBtNumBlocksMask) * kMtBtBlockSize);

 

   if (p->pos > kMtMaxValForNormalize - kMtBtBlockSize)

   {

     UInt32 subValue = p->pos - p->cyclicBufferSize;

     MatchFinder_Normalize3(subValue, p->son, p->cyclicBufferSize * 2);

     p->pos -= subValue;

   }

 

   if (!sync->needStart)

   {

     CriticalSection_Leave(&sync->cs);

     sync->csWasEntered = False;

   }

 }

 

 void BtThreadFunc(CMatchFinderMt *mt)

 {

   CMtSync *p = &mt->btSync;

   for (;;)

   {

     UInt32 blockIndex = 0;

     Event_Wait(&p->canStart);

     Event_Set(&p->wasStarted);

     for (;;)

     {

       if (p->exit)

         return;

       if (p->stopWriting)

       {

         p->numProcessedBlocks = blockIndex;

         MtSync_StopWriting(&mt->hashSync);

         Event_Set(&p->wasStopped);

         break;

       }

       Semaphore_Wait(&p->freeSemaphore);

       BtFillBlock(mt, blockIndex++);

       Semaphore_Release1(&p->filledSemaphore);

     }

   }

 }

 

 void MatchFinderMt_Construct(CMatchFinderMt *p)

 {

   p->hashBuf = 0;

   MtSync_Construct(&p->hashSync);

   MtSync_Construct(&p->btSync);

 }

 

 void MatchFinderMt_FreeMem(CMatchFinderMt *p, ISzAlloc *alloc)

 {

   alloc->Free(alloc, p->hashBuf);

   p->hashBuf = 0;

 }

 

 void MatchFinderMt_Destruct(CMatchFinderMt *p, ISzAlloc *alloc)

 {

   MtSync_Destruct(&p->hashSync);

   MtSync_Destruct(&p->btSync);

   MatchFinderMt_FreeMem(p, alloc);

 }

 

 #define kHashBufferSize (kMtHashBlockSize * kMtHashNumBlocks)

 #define kBtBufferSize (kMtBtBlockSize * kMtBtNumBlocks)

 

 static unsigned MY_STD_CALL HashThreadFunc2(void *p) { HashThreadFunc((CMatchFinderMt *)p);  return 0; }

 static unsigned MY_STD_CALL BtThreadFunc2(void *p)

 {

   Byte allocaDummy[0x180];

   int i = 0;

   for (i = 0; i < 16; i++)

     allocaDummy[i] = (Byte)i;

   BtThreadFunc((CMatchFinderMt *)p);

   return 0;

 }

 

 SRes MatchFinderMt_Create(CMatchFinderMt *p, UInt32 historySize, UInt32 keepAddBufferBefore,

     UInt32 matchMaxLen, UInt32 keepAddBufferAfter, ISzAlloc *alloc)

 {

   CMatchFinder *mf = p->MatchFinder;

   p->historySize = historySize;

   if (kMtBtBlockSize <= matchMaxLen * 4)

     return SZ_ERROR_PARAM;

   if (p->hashBuf == 0)

   {

     p->hashBuf = (UInt32 *)alloc->Alloc(alloc, (kHashBufferSize + kBtBufferSize) * sizeof(UInt32));

     if (p->hashBuf == 0)

       return SZ_ERROR_MEM;

     p->btBuf = p->hashBuf + kHashBufferSize;

   }

   keepAddBufferBefore += (kHashBufferSize + kBtBufferSize);

   keepAddBufferAfter += kMtHashBlockSize;

   if (!MatchFinder_Create(mf, historySize, keepAddBufferBefore, matchMaxLen, keepAddBufferAfter, alloc))

     return SZ_ERROR_MEM;

 

   RINOK(MtSync_Create(&p->hashSync, HashThreadFunc2, p, kMtHashNumBlocks));

   RINOK(MtSync_Create(&p->btSync, BtThreadFunc2, p, kMtBtNumBlocks));

   return SZ_OK;

 }

 

 /* Call it after ReleaseStream / SetStream */

 void MatchFinderMt_Init(CMatchFinderMt *p)

 {

   CMatchFinder *mf = p->MatchFinder;

   p->btBufPos = p->btBufPosLimit = 0;

   p->hashBufPos = p->hashBufPosLimit = 0;

   MatchFinder_Init(mf);

   p->pointerToCurPos = MatchFinder_GetPointerToCurrentPos(mf);

   p->btNumAvailBytes = 0;

   p->lzPos = p->historySize + 1;

 

   p->hash = mf->hash;

   p->fixedHashSize = mf->fixedHashSize;

   p->crc = mf->crc;

 

   p->son = mf->son;

   p->matchMaxLen = mf->matchMaxLen;

   p->numHashBytes = mf->numHashBytes;

   p->pos = mf->pos;

   p->buffer = mf->buffer;

   p->cyclicBufferPos = mf->cyclicBufferPos;

   p->cyclicBufferSize = mf->cyclicBufferSize;

   p->cutValue = mf->cutValue;

 }

 

 /* ReleaseStream is required to finish multithreading */

 void MatchFinderMt_ReleaseStream(CMatchFinderMt *p)

 {

   MtSync_StopWriting(&p->btSync);

   /* p->MatchFinder->ReleaseStream(); */

 }

 

 void MatchFinderMt_Normalize(CMatchFinderMt *p)

 {

   MatchFinder_Normalize3(p->lzPos - p->historySize - 1, p->hash, p->fixedHashSize);

   p->lzPos = p->historySize + 1;

 }

 

 void MatchFinderMt_GetNextBlock_Bt(CMatchFinderMt *p)

 {

   UInt32 blockIndex;

   MtSync_GetNextBlock(&p->btSync);

   blockIndex = ((p->btSync.numProcessedBlocks - 1) & kMtBtNumBlocksMask);

   p->btBufPosLimit = p->btBufPos = blockIndex * kMtBtBlockSize;

   p->btBufPosLimit += p->btBuf[p->btBufPos++];

   p->btNumAvailBytes = p->btBuf[p->btBufPos++];

   if (p->lzPos >= kMtMaxValForNormalize - kMtBtBlockSize)

     MatchFinderMt_Normalize(p);

 }

 

 const Byte * MatchFinderMt_GetPointerToCurrentPos(CMatchFinderMt *p)

 {

   return p->pointerToCurPos;

 }

 

 #define GET_NEXT_BLOCK_IF_REQUIRED if (p->btBufPos == p->btBufPosLimit) MatchFinderMt_GetNextBlock_Bt(p);

 

 UInt32 MatchFinderMt_GetNumAvailableBytes(CMatchFinderMt *p)

 {

   GET_NEXT_BLOCK_IF_REQUIRED;

   return p->btNumAvailBytes;

 }

 

 Byte MatchFinderMt_GetIndexByte(CMatchFinderMt *p, Int32 index)

 {

   return p->pointerToCurPos[index];

 }

 

 UInt32 * MixMatches2(CMatchFinderMt *p, UInt32 matchMinPos, UInt32 *distances)

 {

   UInt32 hash2Value, curMatch2;

   UInt32 *hash = p->hash;

   const Byte *cur = p->pointerToCurPos;

   UInt32 lzPos = p->lzPos;

   MT_HASH2_CALC

       

   curMatch2 = hash[hash2Value];

   hash[hash2Value] = lzPos;

 

   if (curMatch2 >= matchMinPos)

     if (cur[(ptrdiff_t)curMatch2 - lzPos] == cur[0])

     {

       *distances++ = 2;

       *distances++ = lzPos - curMatch2 - 1;

     }

   return distances;

 }

 

 UInt32 * MixMatches3(CMatchFinderMt *p, UInt32 matchMinPos, UInt32 *distances)

 {

   UInt32 hash2Value, hash3Value, curMatch2, curMatch3;

   UInt32 *hash = p->hash;

   const Byte *cur = p->pointerToCurPos;

   UInt32 lzPos = p->lzPos;

   MT_HASH3_CALC

 

   curMatch2 = hash[                hash2Value];

   curMatch3 = hash[kFix3HashSize + hash3Value];

   

   hash[                hash2Value] =

   hash[kFix3HashSize + hash3Value] =

     lzPos;

 

   if (curMatch2 >= matchMinPos && cur[(ptrdiff_t)curMatch2 - lzPos] == cur[0])

   {

     distances[1] = lzPos - curMatch2 - 1;

     if (cur[(ptrdiff_t)curMatch2 - lzPos + 2] == cur[2])

     {

       distances[0] = 3;

       return distances + 2;

     }

     distances[0] = 2;

     distances += 2;

   }

   if (curMatch3 >= matchMinPos && cur[(ptrdiff_t)curMatch3 - lzPos] == cur[0])

   {

     *distances++ = 3;

     *distances++ = lzPos - curMatch3 - 1;

   }

   return distances;

 }

 

 /*

 UInt32 *MixMatches4(CMatchFinderMt *p, UInt32 matchMinPos, UInt32 *distances)

 {

   UInt32 hash2Value, hash3Value, hash4Value, curMatch2, curMatch3, curMatch4;

   UInt32 *hash = p->hash;

   const Byte *cur = p->pointerToCurPos;

   UInt32 lzPos = p->lzPos;

   MT_HASH4_CALC

       

   curMatch2 = hash[                hash2Value];

   curMatch3 = hash[kFix3HashSize + hash3Value];

   curMatch4 = hash[kFix4HashSize + hash4Value];

   

   hash[                hash2Value] =

   hash[kFix3HashSize + hash3Value] =

   hash[kFix4HashSize + hash4Value] =

     lzPos;

 

   if (curMatch2 >= matchMinPos && cur[(ptrdiff_t)curMatch2 - lzPos] == cur[0])

   {

     distances[1] = lzPos - curMatch2 - 1;

     if (cur[(ptrdiff_t)curMatch2 - lzPos + 2] == cur[2])

     {

       distances[0] =  (cur[(ptrdiff_t)curMatch2 - lzPos + 3] == cur[3]) ? 4 : 3;

       return distances + 2;

     }

     distances[0] = 2;

     distances += 2;

   }

   if (curMatch3 >= matchMinPos && cur[(ptrdiff_t)curMatch3 - lzPos] == cur[0])

   {

     distances[1] = lzPos - curMatch3 - 1;

     if (cur[(ptrdiff_t)curMatch3 - lzPos + 3] == cur[3])

     {

       distances[0] = 4;

       return distances + 2;

     }

     distances[0] = 3;

     distances += 2;

   }

 

   if (curMatch4 >= matchMinPos)

     if (

       cur[(ptrdiff_t)curMatch4 - lzPos] == cur[0] &&

       cur[(ptrdiff_t)curMatch4 - lzPos + 3] == cur[3]

       )

     {

       *distances++ = 4;

       *distances++ = lzPos - curMatch4 - 1;

     }

   return distances;

 }

 */

 

 #define INCREASE_LZ_POS p->lzPos++; p->pointerToCurPos++;

 

 UInt32 MatchFinderMt2_GetMatches(CMatchFinderMt *p, UInt32 *distances)

 {

   const UInt32 *btBuf = p->btBuf + p->btBufPos;

   UInt32 len = *btBuf++;

   p->btBufPos += 1 + len;

   p->btNumAvailBytes--;

   {

     UInt32 i;

     for (i = 0; i < len; i += 2)

     {

       *distances++ = *btBuf++;

       *distances++ = *btBuf++;

     }

   }

   INCREASE_LZ_POS

   return len;

 }

 

 UInt32 MatchFinderMt_GetMatches(CMatchFinderMt *p, UInt32 *distances)

 {

   const UInt32 *btBuf = p->btBuf + p->btBufPos;

   UInt32 len = *btBuf++;

   p->btBufPos += 1 + len;

 

   if (len == 0)

   {

     if (p->btNumAvailBytes-- >= 4)

       len = (UInt32)(p->MixMatchesFunc(p, p->lzPos - p->historySize, distances) - (distances));

   }

   else

   {

     /* Condition: there are matches in btBuf with length < p->numHashBytes */

     UInt32 *distances2;

     p->btNumAvailBytes--;

     distances2 = p->MixMatchesFunc(p, p->lzPos - btBuf[1], distances);

     do

     {

       *distances2++ = *btBuf++;

       *distances2++ = *btBuf++;

     }

     while ((len -= 2) != 0);

     len  = (UInt32)(distances2 - (distances));

   }

   INCREASE_LZ_POS

   return len;

 }

 

 #define SKIP_HEADER2  do { GET_NEXT_BLOCK_IF_REQUIRED

 #define SKIP_HEADER(n) SKIP_HEADER2 if (p->btNumAvailBytes-- >= (n)) { const Byte *cur = p->pointerToCurPos; UInt32 *hash = p->hash;

 #define SKIP_FOOTER } INCREASE_LZ_POS p->btBufPos += p->btBuf[p->btBufPos] + 1; } while (--num != 0);

 

 void MatchFinderMt0_Skip(CMatchFinderMt *p, UInt32 num)

 {

   SKIP_HEADER2 { p->btNumAvailBytes--;

   SKIP_FOOTER

 }

 

 void MatchFinderMt2_Skip(CMatchFinderMt *p, UInt32 num)

 {

   SKIP_HEADER(2)

       UInt32 hash2Value;

       MT_HASH2_CALC

       hash[hash2Value] = p->lzPos;

   SKIP_FOOTER

 }

 

 void MatchFinderMt3_Skip(CMatchFinderMt *p, UInt32 num)

 {

   SKIP_HEADER(3)

       UInt32 hash2Value, hash3Value;

       MT_HASH3_CALC

       hash[kFix3HashSize + hash3Value] =

       hash[                hash2Value] =

         p->lzPos;

   SKIP_FOOTER

 }

 

 /*

 void MatchFinderMt4_Skip(CMatchFinderMt *p, UInt32 num)

 {

   SKIP_HEADER(4)

       UInt32 hash2Value, hash3Value, hash4Value;

       MT_HASH4_CALC

       hash[kFix4HashSize + hash4Value] =

       hash[kFix3HashSize + hash3Value] =

       hash[                hash2Value] =

         p->lzPos;

   SKIP_FOOTER

 }

 */

 

 void MatchFinderMt_CreateVTable(CMatchFinderMt *p, IMatchFinder *vTable)

 {

   vTable->Init = (Mf_Init_Func)MatchFinderMt_Init;

   vTable->GetIndexByte = (Mf_GetIndexByte_Func)MatchFinderMt_GetIndexByte;

   vTable->GetNumAvailableBytes = (Mf_GetNumAvailableBytes_Func)MatchFinderMt_GetNumAvailableBytes;

   vTable->GetPointerToCurrentPos = (Mf_GetPointerToCurrentPos_Func)MatchFinderMt_GetPointerToCurrentPos;

   vTable->GetMatches = (Mf_GetMatches_Func)MatchFinderMt_GetMatches;

   switch(p->MatchFinder->numHashBytes)

   {

     case 2:

       p->GetHeadsFunc = GetHeads2;

       p->MixMatchesFunc = (Mf_Mix_Matches)0;

       vTable->Skip = (Mf_Skip_Func)MatchFinderMt0_Skip;

       vTable->GetMatches = (Mf_GetMatches_Func)MatchFinderMt2_GetMatches;

       break;

     case 3:

       p->GetHeadsFunc = GetHeads3;

       p->MixMatchesFunc = (Mf_Mix_Matches)MixMatches2;

       vTable->Skip = (Mf_Skip_Func)MatchFinderMt2_Skip;

       break;

     default:

     /* case 4: */

       p->GetHeadsFunc = p->MatchFinder->bigHash ? GetHeads4b : GetHeads4;

       /* p->GetHeadsFunc = GetHeads4; */

       p->MixMatchesFunc = (Mf_Mix_Matches)MixMatches3;

       vTable->Skip = (Mf_Skip_Func)MatchFinderMt3_Skip;

       break;

     /*

     default:

       p->GetHeadsFunc = GetHeads5;

       p->MixMatchesFunc = (Mf_Mix_Matches)MixMatches4;

       vTable->Skip = (Mf_Skip_Func)MatchFinderMt4_Skip;

       break;

     */

   }

 }