1 /* LzFindMt.c -- multithreaded Match finder for LZ algorithms
2 2009-09-20 : Igor Pavlov : Public domain */
3 
4 #include "LzHash.h"
5 
6 #include "LzFindMt.h"
7 
MtSync_Construct(CMtSync * p)8 void MtSync_Construct(CMtSync *p)
9 {
10   p->wasCreated = False;
11   p->csWasInitialized = False;
12   p->csWasEntered = False;
13   Thread_Construct(&p->thread);
14   Event_Construct(&p->canStart);
15   Event_Construct(&p->wasStarted);
16   Event_Construct(&p->wasStopped);
17   Semaphore_Construct(&p->freeSemaphore);
18   Semaphore_Construct(&p->filledSemaphore);
19 }
20 
MtSync_GetNextBlock(CMtSync * p)21 void MtSync_GetNextBlock(CMtSync *p)
22 {
23   if (p->needStart)
24   {
25     p->numProcessedBlocks = 1;
26     p->needStart = False;
27     p->stopWriting = False;
28     p->exit = False;
29     Event_Reset(&p->wasStarted);
30     Event_Reset(&p->wasStopped);
31 
32     Event_Set(&p->canStart);
33     Event_Wait(&p->wasStarted);
34   }
35   else
36   {
37     CriticalSection_Leave(&p->cs);
38     p->csWasEntered = False;
39     p->numProcessedBlocks++;
40     Semaphore_Release1(&p->freeSemaphore);
41   }
42   Semaphore_Wait(&p->filledSemaphore);
43   CriticalSection_Enter(&p->cs);
44   p->csWasEntered = True;
45 }
46 
47 /* MtSync_StopWriting must be called if Writing was started */
48 
MtSync_StopWriting(CMtSync * p)49 void MtSync_StopWriting(CMtSync *p)
50 {
51   UInt32 myNumBlocks = p->numProcessedBlocks;
52   if (!Thread_WasCreated(&p->thread) || p->needStart)
53     return;
54   p->stopWriting = True;
55   if (p->csWasEntered)
56   {
57     CriticalSection_Leave(&p->cs);
58     p->csWasEntered = False;
59   }
60   Semaphore_Release1(&p->freeSemaphore);
61 
62   Event_Wait(&p->wasStopped);
63 
64   while (myNumBlocks++ != p->numProcessedBlocks)
65   {
66     Semaphore_Wait(&p->filledSemaphore);
67     Semaphore_Release1(&p->freeSemaphore);
68   }
69   p->needStart = True;
70 }
71 
MtSync_Destruct(CMtSync * p)72 void MtSync_Destruct(CMtSync *p)
73 {
74   if (Thread_WasCreated(&p->thread))
75   {
76     MtSync_StopWriting(p);
77     p->exit = True;
78     if (p->needStart)
79       Event_Set(&p->canStart);
80     Thread_Wait(&p->thread);
81     Thread_Close(&p->thread);
82   }
83   if (p->csWasInitialized)
84   {
85     CriticalSection_Delete(&p->cs);
86     p->csWasInitialized = False;
87   }
88 
89   Event_Close(&p->canStart);
90   Event_Close(&p->wasStarted);
91   Event_Close(&p->wasStopped);
92   Semaphore_Close(&p->freeSemaphore);
93   Semaphore_Close(&p->filledSemaphore);
94 
95   p->wasCreated = False;
96 }
97 
98 #define RINOK_THREAD(x) { if ((x) != 0) return SZ_ERROR_THREAD; }
99 
MtSync_Create2(CMtSync * p,unsigned (MY_STD_CALL * startAddress)(void *),void * obj,UInt32 numBlocks)100 static SRes MtSync_Create2(CMtSync *p, unsigned (MY_STD_CALL *startAddress)(void *), void *obj, UInt32 numBlocks)
101 {
102   if (p->wasCreated)
103     return SZ_OK;
104 
105   RINOK_THREAD(CriticalSection_Init(&p->cs));
106   p->csWasInitialized = True;
107 
108   RINOK_THREAD(AutoResetEvent_CreateNotSignaled(&p->canStart));
109   RINOK_THREAD(AutoResetEvent_CreateNotSignaled(&p->wasStarted));
110   RINOK_THREAD(AutoResetEvent_CreateNotSignaled(&p->wasStopped));
111 
112   RINOK_THREAD(Semaphore_Create(&p->freeSemaphore, numBlocks, numBlocks));
113   RINOK_THREAD(Semaphore_Create(&p->filledSemaphore, 0, numBlocks));
114 
115   p->needStart = True;
116 
117   RINOK_THREAD(Thread_Create(&p->thread, startAddress, obj));
118   p->wasCreated = True;
119   return SZ_OK;
120 }
121 
MtSync_Create(CMtSync * p,unsigned (MY_STD_CALL * startAddress)(void *),void * obj,UInt32 numBlocks)122 static SRes MtSync_Create(CMtSync *p, unsigned (MY_STD_CALL *startAddress)(void *), void *obj, UInt32 numBlocks)
123 {
124   SRes res = MtSync_Create2(p, startAddress, obj, numBlocks);
125   if (res != SZ_OK)
126     MtSync_Destruct(p);
127   return res;
128 }
129 
MtSync_Init(CMtSync * p)130 void MtSync_Init(CMtSync *p) { p->needStart = True; }
131 
132 #define kMtMaxValForNormalize 0xFFFFFFFF
133 
134 #define DEF_GetHeads2(name, v, action) \
135 static void GetHeads ## name(const Byte *p, UInt32 pos, \
136 UInt32 *hash, UInt32 hashMask, UInt32 *heads, UInt32 numHeads, const UInt32 *crc) \
137 { action; for (; numHeads != 0; numHeads--) { \
138 const UInt32 value = (v); p++; *heads++ = pos - hash[value]; hash[value] = pos++;  } }
139 
140 #define DEF_GetHeads(name, v) DEF_GetHeads2(name, v, ;)
141 
142 DEF_GetHeads2(2,  (p[0] | ((UInt32)p[1] << 8)), hashMask = hashMask; crc = crc; )
143 DEF_GetHeads(3,  (crc[p[0]] ^ p[1] ^ ((UInt32)p[2] << 8)) & hashMask)
144 DEF_GetHeads(4,  (crc[p[0]] ^ p[1] ^ ((UInt32)p[2] << 8) ^ (crc[p[3]] << 5)) & hashMask)
145 DEF_GetHeads(4b, (crc[p[0]] ^ p[1] ^ ((UInt32)p[2] << 8) ^ ((UInt32)p[3] << 16)) & hashMask)
146 /* DEF_GetHeads(5,  (crc[p[0]] ^ p[1] ^ ((UInt32)p[2] << 8) ^ (crc[p[3]] << 5) ^ (crc[p[4]] << 3)) & hashMask) */
147 
HashThreadFunc(CMatchFinderMt * mt)148 void HashThreadFunc(CMatchFinderMt *mt)
149 {
150   CMtSync *p = &mt->hashSync;
151   for (;;)
152   {
153     UInt32 numProcessedBlocks = 0;
154     Event_Wait(&p->canStart);
155     Event_Set(&p->wasStarted);
156     for (;;)
157     {
158       if (p->exit)
159         return;
160       if (p->stopWriting)
161       {
162         p->numProcessedBlocks = numProcessedBlocks;
163         Event_Set(&p->wasStopped);
164         break;
165       }
166 
167       {
168         CMatchFinder *mf = mt->MatchFinder;
169         if (MatchFinder_NeedMove(mf))
170         {
171           CriticalSection_Enter(&mt->btSync.cs);
172           CriticalSection_Enter(&mt->hashSync.cs);
173           {
174             const Byte *beforePtr = MatchFinder_GetPointerToCurrentPos(mf);
175             const Byte *afterPtr;
176             MatchFinder_MoveBlock(mf);
177             afterPtr = MatchFinder_GetPointerToCurrentPos(mf);
178             mt->pointerToCurPos -= beforePtr - afterPtr;
179             mt->buffer -= beforePtr - afterPtr;
180           }
181           CriticalSection_Leave(&mt->btSync.cs);
182           CriticalSection_Leave(&mt->hashSync.cs);
183           continue;
184         }
185 
186         Semaphore_Wait(&p->freeSemaphore);
187 
188         MatchFinder_ReadIfRequired(mf);
189         if (mf->pos > (kMtMaxValForNormalize - kMtHashBlockSize))
190         {
191           UInt32 subValue = (mf->pos - mf->historySize - 1);
192           MatchFinder_ReduceOffsets(mf, subValue);
193           MatchFinder_Normalize3(subValue, mf->hash + mf->fixedHashSize, mf->hashMask + 1);
194         }
195         {
196           UInt32 *heads = mt->hashBuf + ((numProcessedBlocks++) & kMtHashNumBlocksMask) * kMtHashBlockSize;
197           UInt32 num = mf->streamPos - mf->pos;
198           heads[0] = 2;
199           heads[1] = num;
200           if (num >= mf->numHashBytes)
201           {
202             num = num - mf->numHashBytes + 1;
203             if (num > kMtHashBlockSize - 2)
204               num = kMtHashBlockSize - 2;
205             mt->GetHeadsFunc(mf->buffer, mf->pos, mf->hash + mf->fixedHashSize, mf->hashMask, heads + 2, num, mf->crc);
206             heads[0] += num;
207           }
208           mf->pos += num;
209           mf->buffer += num;
210         }
211       }
212 
213       Semaphore_Release1(&p->filledSemaphore);
214     }
215   }
216 }
217 
MatchFinderMt_GetNextBlock_Hash(CMatchFinderMt * p)218 void MatchFinderMt_GetNextBlock_Hash(CMatchFinderMt *p)
219 {
220   MtSync_GetNextBlock(&p->hashSync);
221   p->hashBufPosLimit = p->hashBufPos = ((p->hashSync.numProcessedBlocks - 1) & kMtHashNumBlocksMask) * kMtHashBlockSize;
222   p->hashBufPosLimit += p->hashBuf[p->hashBufPos++];
223   p->hashNumAvail = p->hashBuf[p->hashBufPos++];
224 }
225 
226 #define kEmptyHashValue 0
227 
228 /* #define MFMT_GM_INLINE */
229 
230 #ifdef MFMT_GM_INLINE
231 
232 #define NO_INLINE MY_FAST_CALL
233 
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)234 Int32 NO_INLINE GetMatchesSpecN(UInt32 lenLimit, UInt32 pos, const Byte *cur, CLzRef *son,
235     UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 _cutValue,
236     UInt32 *_distances, UInt32 _maxLen, const UInt32 *hash, Int32 limit, UInt32 size, UInt32 *posRes)
237 {
238   do
239   {
240   UInt32 *distances = _distances + 1;
241   UInt32 curMatch = pos - *hash++;
242 
243   CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;
244   CLzRef *ptr1 = son + (_cyclicBufferPos << 1);
245   UInt32 len0 = 0, len1 = 0;
246   UInt32 cutValue = _cutValue;
247   UInt32 maxLen = _maxLen;
248   for (;;)
249   {
250     UInt32 delta = pos - curMatch;
251     if (cutValue-- == 0 || delta >= _cyclicBufferSize)
252     {
253       *ptr0 = *ptr1 = kEmptyHashValue;
254       break;
255     }
256     {
257       CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);
258       const Byte *pb = cur - delta;
259       UInt32 len = (len0 < len1 ? len0 : len1);
260       if (pb[len] == cur[len])
261       {
262         if (++len != lenLimit && pb[len] == cur[len])
263           while (++len != lenLimit)
264             if (pb[len] != cur[len])
265               break;
266         if (maxLen < len)
267         {
268           *distances++ = maxLen = len;
269           *distances++ = delta - 1;
270           if (len == lenLimit)
271           {
272             *ptr1 = pair[0];
273             *ptr0 = pair[1];
274             break;
275           }
276         }
277       }
278       if (pb[len] < cur[len])
279       {
280         *ptr1 = curMatch;
281         ptr1 = pair + 1;
282         curMatch = *ptr1;
283         len1 = len;
284       }
285       else
286       {
287         *ptr0 = curMatch;
288         ptr0 = pair;
289         curMatch = *ptr0;
290         len0 = len;
291       }
292     }
293   }
294   pos++;
295   _cyclicBufferPos++;
296   cur++;
297   {
298     UInt32 num = (UInt32)(distances - _distances);
299     *_distances = num - 1;
300     _distances += num;
301     limit -= num;
302   }
303   }
304   while (limit > 0 && --size != 0);
305   *posRes = pos;
306   return limit;
307 }
308 
309 #endif
310 
BtGetMatches(CMatchFinderMt * p,UInt32 * distances)311 void BtGetMatches(CMatchFinderMt *p, UInt32 *distances)
312 {
313   UInt32 numProcessed = 0;
314   UInt32 curPos = 2;
315   UInt32 limit = kMtBtBlockSize - (p->matchMaxLen * 2);
316   distances[1] = p->hashNumAvail;
317   while (curPos < limit)
318   {
319     if (p->hashBufPos == p->hashBufPosLimit)
320     {
321       MatchFinderMt_GetNextBlock_Hash(p);
322       distances[1] = numProcessed + p->hashNumAvail;
323       if (p->hashNumAvail >= p->numHashBytes)
324         continue;
325       for (; p->hashNumAvail != 0; p->hashNumAvail--)
326         distances[curPos++] = 0;
327       break;
328     }
329     {
330       UInt32 size = p->hashBufPosLimit - p->hashBufPos;
331       UInt32 lenLimit = p->matchMaxLen;
332       UInt32 pos = p->pos;
333       UInt32 cyclicBufferPos = p->cyclicBufferPos;
334       if (lenLimit >= p->hashNumAvail)
335         lenLimit = p->hashNumAvail;
336       {
337         UInt32 size2 = p->hashNumAvail - lenLimit + 1;
338         if (size2 < size)
339           size = size2;
340         size2 = p->cyclicBufferSize - cyclicBufferPos;
341         if (size2 < size)
342           size = size2;
343       }
344       #ifndef MFMT_GM_INLINE
345       while (curPos < limit && size-- != 0)
346       {
347         UInt32 *startDistances = distances + curPos;
348         UInt32 num = (UInt32)(GetMatchesSpec1(lenLimit, pos - p->hashBuf[p->hashBufPos++],
349           pos, p->buffer, p->son, cyclicBufferPos, p->cyclicBufferSize, p->cutValue,
350           startDistances + 1, p->numHashBytes - 1) - startDistances);
351         *startDistances = num - 1;
352         curPos += num;
353         cyclicBufferPos++;
354         pos++;
355         p->buffer++;
356       }
357       #else
358       {
359         UInt32 posRes;
360         curPos = limit - GetMatchesSpecN(lenLimit, pos, p->buffer, p->son, cyclicBufferPos, p->cyclicBufferSize, p->cutValue,
361           distances + curPos, p->numHashBytes - 1, p->hashBuf + p->hashBufPos, (Int32)(limit - curPos) , size, &posRes);
362         p->hashBufPos += posRes - pos;
363         cyclicBufferPos += posRes - pos;
364         p->buffer += posRes - pos;
365         pos = posRes;
366       }
367       #endif
368 
369       numProcessed += pos - p->pos;
370       p->hashNumAvail -= pos - p->pos;
371       p->pos = pos;
372       if (cyclicBufferPos == p->cyclicBufferSize)
373         cyclicBufferPos = 0;
374       p->cyclicBufferPos = cyclicBufferPos;
375     }
376   }
377   distances[0] = curPos;
378 }
379 
BtFillBlock(CMatchFinderMt * p,UInt32 globalBlockIndex)380 void BtFillBlock(CMatchFinderMt *p, UInt32 globalBlockIndex)
381 {
382   CMtSync *sync = &p->hashSync;
383   if (!sync->needStart)
384   {
385     CriticalSection_Enter(&sync->cs);
386     sync->csWasEntered = True;
387   }
388 
389   BtGetMatches(p, p->btBuf + (globalBlockIndex & kMtBtNumBlocksMask) * kMtBtBlockSize);
390 
391   if (p->pos > kMtMaxValForNormalize - kMtBtBlockSize)
392   {
393     UInt32 subValue = p->pos - p->cyclicBufferSize;
394     MatchFinder_Normalize3(subValue, p->son, p->cyclicBufferSize * 2);
395     p->pos -= subValue;
396   }
397 
398   if (!sync->needStart)
399   {
400     CriticalSection_Leave(&sync->cs);
401     sync->csWasEntered = False;
402   }
403 }
404 
BtThreadFunc(CMatchFinderMt * mt)405 void BtThreadFunc(CMatchFinderMt *mt)
406 {
407   CMtSync *p = &mt->btSync;
408   for (;;)
409   {
410     UInt32 blockIndex = 0;
411     Event_Wait(&p->canStart);
412     Event_Set(&p->wasStarted);
413     for (;;)
414     {
415       if (p->exit)
416         return;
417       if (p->stopWriting)
418       {
419         p->numProcessedBlocks = blockIndex;
420         MtSync_StopWriting(&mt->hashSync);
421         Event_Set(&p->wasStopped);
422         break;
423       }
424       Semaphore_Wait(&p->freeSemaphore);
425       BtFillBlock(mt, blockIndex++);
426       Semaphore_Release1(&p->filledSemaphore);
427     }
428   }
429 }
430 
MatchFinderMt_Construct(CMatchFinderMt * p)431 void MatchFinderMt_Construct(CMatchFinderMt *p)
432 {
433   p->hashBuf = 0;
434   MtSync_Construct(&p->hashSync);
435   MtSync_Construct(&p->btSync);
436 }
437 
MatchFinderMt_FreeMem(CMatchFinderMt * p,ISzAlloc * alloc)438 void MatchFinderMt_FreeMem(CMatchFinderMt *p, ISzAlloc *alloc)
439 {
440   alloc->Free(alloc, p->hashBuf);
441   p->hashBuf = 0;
442 }
443 
MatchFinderMt_Destruct(CMatchFinderMt * p,ISzAlloc * alloc)444 void MatchFinderMt_Destruct(CMatchFinderMt *p, ISzAlloc *alloc)
445 {
446   MtSync_Destruct(&p->hashSync);
447   MtSync_Destruct(&p->btSync);
448   MatchFinderMt_FreeMem(p, alloc);
449 }
450 
451 #define kHashBufferSize (kMtHashBlockSize * kMtHashNumBlocks)
452 #define kBtBufferSize (kMtBtBlockSize * kMtBtNumBlocks)
453 
HashThreadFunc2(void * p)454 static unsigned MY_STD_CALL HashThreadFunc2(void *p) { HashThreadFunc((CMatchFinderMt *)p);  return 0; }
BtThreadFunc2(void * p)455 static unsigned MY_STD_CALL BtThreadFunc2(void *p)
456 {
457   Byte allocaDummy[0x180];
458   int i = 0;
459   for (i = 0; i < 16; i++)
460     allocaDummy[i] = (Byte)i;
461   BtThreadFunc((CMatchFinderMt *)p);
462   return 0;
463 }
464 
MatchFinderMt_Create(CMatchFinderMt * p,UInt32 historySize,UInt32 keepAddBufferBefore,UInt32 matchMaxLen,UInt32 keepAddBufferAfter,ISzAlloc * alloc)465 SRes MatchFinderMt_Create(CMatchFinderMt *p, UInt32 historySize, UInt32 keepAddBufferBefore,
466     UInt32 matchMaxLen, UInt32 keepAddBufferAfter, ISzAlloc *alloc)
467 {
468   CMatchFinder *mf = p->MatchFinder;
469   p->historySize = historySize;
470   if (kMtBtBlockSize <= matchMaxLen * 4)
471     return SZ_ERROR_PARAM;
472   if (p->hashBuf == 0)
473   {
474     p->hashBuf = (UInt32 *)alloc->Alloc(alloc, (kHashBufferSize + kBtBufferSize) * sizeof(UInt32));
475     if (p->hashBuf == 0)
476       return SZ_ERROR_MEM;
477     p->btBuf = p->hashBuf + kHashBufferSize;
478   }
479   keepAddBufferBefore += (kHashBufferSize + kBtBufferSize);
480   keepAddBufferAfter += kMtHashBlockSize;
481   if (!MatchFinder_Create(mf, historySize, keepAddBufferBefore, matchMaxLen, keepAddBufferAfter, alloc))
482     return SZ_ERROR_MEM;
483 
484   RINOK(MtSync_Create(&p->hashSync, HashThreadFunc2, p, kMtHashNumBlocks));
485   RINOK(MtSync_Create(&p->btSync, BtThreadFunc2, p, kMtBtNumBlocks));
486   return SZ_OK;
487 }
488 
489 /* Call it after ReleaseStream / SetStream */
MatchFinderMt_Init(CMatchFinderMt * p)490 void MatchFinderMt_Init(CMatchFinderMt *p)
491 {
492   CMatchFinder *mf = p->MatchFinder;
493   p->btBufPos = p->btBufPosLimit = 0;
494   p->hashBufPos = p->hashBufPosLimit = 0;
495   MatchFinder_Init(mf);
496   p->pointerToCurPos = MatchFinder_GetPointerToCurrentPos(mf);
497   p->btNumAvailBytes = 0;
498   p->lzPos = p->historySize + 1;
499 
500   p->hash = mf->hash;
501   p->fixedHashSize = mf->fixedHashSize;
502   p->crc = mf->crc;
503 
504   p->son = mf->son;
505   p->matchMaxLen = mf->matchMaxLen;
506   p->numHashBytes = mf->numHashBytes;
507   p->pos = mf->pos;
508   p->buffer = mf->buffer;
509   p->cyclicBufferPos = mf->cyclicBufferPos;
510   p->cyclicBufferSize = mf->cyclicBufferSize;
511   p->cutValue = mf->cutValue;
512 }
513 
514 /* ReleaseStream is required to finish multithreading */
MatchFinderMt_ReleaseStream(CMatchFinderMt * p)515 void MatchFinderMt_ReleaseStream(CMatchFinderMt *p)
516 {
517   MtSync_StopWriting(&p->btSync);
518   /* p->MatchFinder->ReleaseStream(); */
519 }
520 
MatchFinderMt_Normalize(CMatchFinderMt * p)521 void MatchFinderMt_Normalize(CMatchFinderMt *p)
522 {
523   MatchFinder_Normalize3(p->lzPos - p->historySize - 1, p->hash, p->fixedHashSize);
524   p->lzPos = p->historySize + 1;
525 }
526 
MatchFinderMt_GetNextBlock_Bt(CMatchFinderMt * p)527 void MatchFinderMt_GetNextBlock_Bt(CMatchFinderMt *p)
528 {
529   UInt32 blockIndex;
530   MtSync_GetNextBlock(&p->btSync);
531   blockIndex = ((p->btSync.numProcessedBlocks - 1) & kMtBtNumBlocksMask);
532   p->btBufPosLimit = p->btBufPos = blockIndex * kMtBtBlockSize;
533   p->btBufPosLimit += p->btBuf[p->btBufPos++];
534   p->btNumAvailBytes = p->btBuf[p->btBufPos++];
535   if (p->lzPos >= kMtMaxValForNormalize - kMtBtBlockSize)
536     MatchFinderMt_Normalize(p);
537 }
538 
MatchFinderMt_GetPointerToCurrentPos(CMatchFinderMt * p)539 const Byte * MatchFinderMt_GetPointerToCurrentPos(CMatchFinderMt *p)
540 {
541   return p->pointerToCurPos;
542 }
543 
544 #define GET_NEXT_BLOCK_IF_REQUIRED if (p->btBufPos == p->btBufPosLimit) MatchFinderMt_GetNextBlock_Bt(p);
545 
MatchFinderMt_GetNumAvailableBytes(CMatchFinderMt * p)546 UInt32 MatchFinderMt_GetNumAvailableBytes(CMatchFinderMt *p)
547 {
548   GET_NEXT_BLOCK_IF_REQUIRED;
549   return p->btNumAvailBytes;
550 }
551 
MatchFinderMt_GetIndexByte(CMatchFinderMt * p,Int32 index)552 Byte MatchFinderMt_GetIndexByte(CMatchFinderMt *p, Int32 index)
553 {
554   return p->pointerToCurPos[index];
555 }
556 
MixMatches2(CMatchFinderMt * p,UInt32 matchMinPos,UInt32 * distances)557 UInt32 * MixMatches2(CMatchFinderMt *p, UInt32 matchMinPos, UInt32 *distances)
558 {
559   UInt32 hash2Value, curMatch2;
560   UInt32 *hash = p->hash;
561   const Byte *cur = p->pointerToCurPos;
562   UInt32 lzPos = p->lzPos;
563   MT_HASH2_CALC
564 
565   curMatch2 = hash[hash2Value];
566   hash[hash2Value] = lzPos;
567 
568   if (curMatch2 >= matchMinPos)
569     if (cur[(ptrdiff_t)curMatch2 - lzPos] == cur[0])
570     {
571       *distances++ = 2;
572       *distances++ = lzPos - curMatch2 - 1;
573     }
574   return distances;
575 }
576 
MixMatches3(CMatchFinderMt * p,UInt32 matchMinPos,UInt32 * distances)577 UInt32 * MixMatches3(CMatchFinderMt *p, UInt32 matchMinPos, UInt32 *distances)
578 {
579   UInt32 hash2Value, hash3Value, curMatch2, curMatch3;
580   UInt32 *hash = p->hash;
581   const Byte *cur = p->pointerToCurPos;
582   UInt32 lzPos = p->lzPos;
583   MT_HASH3_CALC
584 
585   curMatch2 = hash[                hash2Value];
586   curMatch3 = hash[kFix3HashSize + hash3Value];
587 
588   hash[                hash2Value] =
589   hash[kFix3HashSize + hash3Value] =
590     lzPos;
591 
592   if (curMatch2 >= matchMinPos && cur[(ptrdiff_t)curMatch2 - lzPos] == cur[0])
593   {
594     distances[1] = lzPos - curMatch2 - 1;
595     if (cur[(ptrdiff_t)curMatch2 - lzPos + 2] == cur[2])
596     {
597       distances[0] = 3;
598       return distances + 2;
599     }
600     distances[0] = 2;
601     distances += 2;
602   }
603   if (curMatch3 >= matchMinPos && cur[(ptrdiff_t)curMatch3 - lzPos] == cur[0])
604   {
605     *distances++ = 3;
606     *distances++ = lzPos - curMatch3 - 1;
607   }
608   return distances;
609 }
610 
611 /*
612 UInt32 *MixMatches4(CMatchFinderMt *p, UInt32 matchMinPos, UInt32 *distances)
613 {
614   UInt32 hash2Value, hash3Value, hash4Value, curMatch2, curMatch3, curMatch4;
615   UInt32 *hash = p->hash;
616   const Byte *cur = p->pointerToCurPos;
617   UInt32 lzPos = p->lzPos;
618   MT_HASH4_CALC
619 
620   curMatch2 = hash[                hash2Value];
621   curMatch3 = hash[kFix3HashSize + hash3Value];
622   curMatch4 = hash[kFix4HashSize + hash4Value];
623 
624   hash[                hash2Value] =
625   hash[kFix3HashSize + hash3Value] =
626   hash[kFix4HashSize + hash4Value] =
627     lzPos;
628 
629   if (curMatch2 >= matchMinPos && cur[(ptrdiff_t)curMatch2 - lzPos] == cur[0])
630   {
631     distances[1] = lzPos - curMatch2 - 1;
632     if (cur[(ptrdiff_t)curMatch2 - lzPos + 2] == cur[2])
633     {
634       distances[0] =  (cur[(ptrdiff_t)curMatch2 - lzPos + 3] == cur[3]) ? 4 : 3;
635       return distances + 2;
636     }
637     distances[0] = 2;
638     distances += 2;
639   }
640   if (curMatch3 >= matchMinPos && cur[(ptrdiff_t)curMatch3 - lzPos] == cur[0])
641   {
642     distances[1] = lzPos - curMatch3 - 1;
643     if (cur[(ptrdiff_t)curMatch3 - lzPos + 3] == cur[3])
644     {
645       distances[0] = 4;
646       return distances + 2;
647     }
648     distances[0] = 3;
649     distances += 2;
650   }
651 
652   if (curMatch4 >= matchMinPos)
653     if (
654       cur[(ptrdiff_t)curMatch4 - lzPos] == cur[0] &&
655       cur[(ptrdiff_t)curMatch4 - lzPos + 3] == cur[3]
656       )
657     {
658       *distances++ = 4;
659       *distances++ = lzPos - curMatch4 - 1;
660     }
661   return distances;
662 }
663 */
664 
665 #define INCREASE_LZ_POS p->lzPos++; p->pointerToCurPos++;
666 
MatchFinderMt2_GetMatches(CMatchFinderMt * p,UInt32 * distances)667 UInt32 MatchFinderMt2_GetMatches(CMatchFinderMt *p, UInt32 *distances)
668 {
669   const UInt32 *btBuf = p->btBuf + p->btBufPos;
670   UInt32 len = *btBuf++;
671   p->btBufPos += 1 + len;
672   p->btNumAvailBytes--;
673   {
674     UInt32 i;
675     for (i = 0; i < len; i += 2)
676     {
677       *distances++ = *btBuf++;
678       *distances++ = *btBuf++;
679     }
680   }
681   INCREASE_LZ_POS
682   return len;
683 }
684 
MatchFinderMt_GetMatches(CMatchFinderMt * p,UInt32 * distances)685 UInt32 MatchFinderMt_GetMatches(CMatchFinderMt *p, UInt32 *distances)
686 {
687   const UInt32 *btBuf = p->btBuf + p->btBufPos;
688   UInt32 len = *btBuf++;
689   p->btBufPos += 1 + len;
690 
691   if (len == 0)
692   {
693     if (p->btNumAvailBytes-- >= 4)
694       len = (UInt32)(p->MixMatchesFunc(p, p->lzPos - p->historySize, distances) - (distances));
695   }
696   else
697   {
698     /* Condition: there are matches in btBuf with length < p->numHashBytes */
699     UInt32 *distances2;
700     p->btNumAvailBytes--;
701     distances2 = p->MixMatchesFunc(p, p->lzPos - btBuf[1], distances);
702     do
703     {
704       *distances2++ = *btBuf++;
705       *distances2++ = *btBuf++;
706     }
707     while ((len -= 2) != 0);
708     len  = (UInt32)(distances2 - (distances));
709   }
710   INCREASE_LZ_POS
711   return len;
712 }
713 
714 #define SKIP_HEADER2_MT  do { GET_NEXT_BLOCK_IF_REQUIRED
715 #define SKIP_HEADER_MT(n) SKIP_HEADER2_MT if (p->btNumAvailBytes-- >= (n)) { const Byte *cur = p->pointerToCurPos; UInt32 *hash = p->hash;
716 #define SKIP_FOOTER_MT } INCREASE_LZ_POS p->btBufPos += p->btBuf[p->btBufPos] + 1; } while (--num != 0);
717 
MatchFinderMt0_Skip(CMatchFinderMt * p,UInt32 num)718 void MatchFinderMt0_Skip(CMatchFinderMt *p, UInt32 num)
719 {
720   SKIP_HEADER2_MT { p->btNumAvailBytes--;
721   SKIP_FOOTER_MT
722 }
723 
724 void MatchFinderMt2_Skip(CMatchFinderMt *p, UInt32 num)
725 {
726   SKIP_HEADER_MT(2)
727       UInt32 hash2Value;
728       MT_HASH2_CALC
729       hash[hash2Value] = p->lzPos;
730   SKIP_FOOTER_MT
731 }
732 
733 void MatchFinderMt3_Skip(CMatchFinderMt *p, UInt32 num)
734 {
735   SKIP_HEADER_MT(3)
736       UInt32 hash2Value, hash3Value;
737       MT_HASH3_CALC
738       hash[kFix3HashSize + hash3Value] =
739       hash[                hash2Value] =
740         p->lzPos;
741   SKIP_FOOTER_MT
742 }
743 
744 /*
745 void MatchFinderMt4_Skip(CMatchFinderMt *p, UInt32 num)
746 {
747   SKIP_HEADER_MT(4)
748       UInt32 hash2Value, hash3Value, hash4Value;
749       MT_HASH4_CALC
750       hash[kFix4HashSize + hash4Value] =
751       hash[kFix3HashSize + hash3Value] =
752       hash[                hash2Value] =
753         p->lzPos;
754   SKIP_FOOTER_MT
755 }
756 */
757 
758 void MatchFinderMt_CreateVTable(CMatchFinderMt *p, IMatchFinder *vTable)
759 {
760   vTable->Init = (Mf_Init_Func)MatchFinderMt_Init;
761   vTable->GetIndexByte = (Mf_GetIndexByte_Func)MatchFinderMt_GetIndexByte;
762   vTable->GetNumAvailableBytes = (Mf_GetNumAvailableBytes_Func)MatchFinderMt_GetNumAvailableBytes;
763   vTable->GetPointerToCurrentPos = (Mf_GetPointerToCurrentPos_Func)MatchFinderMt_GetPointerToCurrentPos;
764   vTable->GetMatches = (Mf_GetMatches_Func)MatchFinderMt_GetMatches;
765   switch(p->MatchFinder->numHashBytes)
766   {
767     case 2:
768       p->GetHeadsFunc = GetHeads2;
769       p->MixMatchesFunc = (Mf_Mix_Matches)0;
770       vTable->Skip = (Mf_Skip_Func)MatchFinderMt0_Skip;
771       vTable->GetMatches = (Mf_GetMatches_Func)MatchFinderMt2_GetMatches;
772       break;
773     case 3:
774       p->GetHeadsFunc = GetHeads3;
775       p->MixMatchesFunc = (Mf_Mix_Matches)MixMatches2;
776       vTable->Skip = (Mf_Skip_Func)MatchFinderMt2_Skip;
777       break;
778     default:
779     /* case 4: */
780       p->GetHeadsFunc = p->MatchFinder->bigHash ? GetHeads4b : GetHeads4;
781       /* p->GetHeadsFunc = GetHeads4; */
782       p->MixMatchesFunc = (Mf_Mix_Matches)MixMatches3;
783       vTable->Skip = (Mf_Skip_Func)MatchFinderMt3_Skip;
784       break;
785     /*
786     default:
787       p->GetHeadsFunc = GetHeads5;
788       p->MixMatchesFunc = (Mf_Mix_Matches)MixMatches4;
789       vTable->Skip = (Mf_Skip_Func)MatchFinderMt4_Skip;
790       break;
791     */
792   }
793 }
794