1/* LzFind.c -- Match finder for LZ algorithms
22009-04-22 : Igor Pavlov : Public domain
3in the public domain */
4
5#include <string.h>
6
7#include "LzFind.h"
8#include "LzHash.h"
9
10#define kEmptyHashValue 0
11#define kMaxValForNormalize ((UInt32)0xFFFFFFFF)
12#define kNormalizeStepMin (1 << 10) /* it must be power of 2 */
13#define kNormalizeMask (~(kNormalizeStepMin - 1))
14#define kMaxHistorySize ((UInt32)3 << 30)
15
16#define kStartMaxLen 3
17
18static void LzInWindow_Free(CMatchFinder *p, ISzAlloc *alloc)
19{
20  if (!p->directInput)
21  {
22    alloc->Free(alloc, p->bufferBase);
23    p->bufferBase = 0;
24  }
25}
26
27/* keepSizeBefore + keepSizeAfter + keepSizeReserv must be < 4G) */
28
29static int LzInWindow_Create(CMatchFinder *p, UInt32 keepSizeReserv, ISzAlloc *alloc)
30{
31  UInt32 blockSize = p->keepSizeBefore + p->keepSizeAfter + keepSizeReserv;
32  if (p->directInput)
33  {
34    p->blockSize = blockSize;
35    return 1;
36  }
37  if (p->bufferBase == 0 || p->blockSize != blockSize)
38  {
39    LzInWindow_Free(p, alloc);
40    p->blockSize = blockSize;
41    p->bufferBase = (Byte *)alloc->Alloc(alloc, (size_t)blockSize);
42  }
43  return (p->bufferBase != 0);
44}
45
46Byte *MatchFinder_GetPointerToCurrentPos(CMatchFinder *p) { return p->buffer; }
47Byte MatchFinder_GetIndexByte(CMatchFinder *p, Int32 index) { return p->buffer[index]; }
48
49UInt32 MatchFinder_GetNumAvailableBytes(CMatchFinder *p) { return p->streamPos - p->pos; }
50
51void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue)
52{
53  p->posLimit -= subValue;
54  p->pos -= subValue;
55  p->streamPos -= subValue;
56}
57
58static void MatchFinder_ReadBlock(CMatchFinder *p)
59{
60  if (p->streamEndWasReached || p->result != SZ_OK)
61    return;
62  if (p->directInput)
63  {
64    UInt32 curSize = 0xFFFFFFFF - p->streamPos;
65    if (curSize > p->directInputRem)
66      curSize = (UInt32)p->directInputRem;
67    p->directInputRem -= curSize;
68    p->streamPos += curSize;
69    if (p->directInputRem == 0)
70      p->streamEndWasReached = 1;
71    return;
72  }
73  for (;;)
74  {
75    Byte *dest = p->buffer + (p->streamPos - p->pos);
76    size_t size = (p->bufferBase + p->blockSize - dest);
77    if (size == 0)
78      return;
79    p->result = p->stream->Read(p->stream, dest, &size);
80    if (p->result != SZ_OK)
81      return;
82    if (size == 0)
83    {
84      p->streamEndWasReached = 1;
85      return;
86    }
87    p->streamPos += (UInt32)size;
88    if (p->streamPos - p->pos > p->keepSizeAfter)
89      return;
90  }
91}
92
93void MatchFinder_MoveBlock(CMatchFinder *p)
94{
95  memmove(p->bufferBase,
96    p->buffer - p->keepSizeBefore,
97    (size_t)(p->streamPos - p->pos + p->keepSizeBefore));
98  p->buffer = p->bufferBase + p->keepSizeBefore;
99}
100
101int MatchFinder_NeedMove(CMatchFinder *p)
102{
103  if (p->directInput)
104    return 0;
105  /* if (p->streamEndWasReached) return 0; */
106  return ((size_t)(p->bufferBase + p->blockSize - p->buffer) <= p->keepSizeAfter);
107}
108
109void MatchFinder_ReadIfRequired(CMatchFinder *p)
110{
111  if (p->streamEndWasReached)
112    return;
113  if (p->keepSizeAfter >= p->streamPos - p->pos)
114    MatchFinder_ReadBlock(p);
115}
116
117static void MatchFinder_CheckAndMoveAndRead(CMatchFinder *p)
118{
119  if (MatchFinder_NeedMove(p))
120    MatchFinder_MoveBlock(p);
121  MatchFinder_ReadBlock(p);
122}
123
124static void MatchFinder_SetDefaultSettings(CMatchFinder *p)
125{
126  p->cutValue = 32;
127  p->btMode = 1;
128  p->numHashBytes = 4;
129  p->bigHash = 0;
130}
131
132#define kCrcPoly 0xEDB88320
133
134void MatchFinder_Construct(CMatchFinder *p)
135{
136  UInt32 i;
137  p->bufferBase = 0;
138  p->directInput = 0;
139  p->hash = 0;
140  MatchFinder_SetDefaultSettings(p);
141
142  for (i = 0; i < 256; i++)
143  {
144    UInt32 r = i;
145    int j;
146    for (j = 0; j < 8; j++)
147      r = (r >> 1) ^ (kCrcPoly & ~((r & 1) - 1));
148    p->crc[i] = r;
149  }
150}
151
152static void MatchFinder_FreeThisClassMemory(CMatchFinder *p, ISzAlloc *alloc)
153{
154  alloc->Free(alloc, p->hash);
155  p->hash = 0;
156}
157
158void MatchFinder_Free(CMatchFinder *p, ISzAlloc *alloc)
159{
160  MatchFinder_FreeThisClassMemory(p, alloc);
161  LzInWindow_Free(p, alloc);
162}
163
164static CLzRef* AllocRefs(UInt32 num, ISzAlloc *alloc)
165{
166  size_t sizeInBytes = (size_t)num * sizeof(CLzRef);
167  if (sizeInBytes / sizeof(CLzRef) != num)
168    return 0;
169  return (CLzRef *)alloc->Alloc(alloc, sizeInBytes);
170}
171
172int MatchFinder_Create(CMatchFinder *p, UInt32 historySize,
173    UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter,
174    ISzAlloc *alloc)
175{
176  UInt32 sizeReserv;
177  if (historySize > kMaxHistorySize)
178  {
179    MatchFinder_Free(p, alloc);
180    return 0;
181  }
182  sizeReserv = historySize >> 1;
183  if (historySize > ((UInt32)2 << 30))
184    sizeReserv = historySize >> 2;
185  sizeReserv += (keepAddBufferBefore + matchMaxLen + keepAddBufferAfter) / 2 + (1 << 19);
186
187  p->keepSizeBefore = historySize + keepAddBufferBefore + 1;
188  p->keepSizeAfter = matchMaxLen + keepAddBufferAfter;
189  /* we need one additional byte, since we use MoveBlock after pos++ and before dictionary using */
190  if (LzInWindow_Create(p, sizeReserv, alloc))
191  {
192    UInt32 newCyclicBufferSize = historySize + 1;
193    UInt32 hs;
194    p->matchMaxLen = matchMaxLen;
195    {
196      p->fixedHashSize = 0;
197      if (p->numHashBytes == 2)
198        hs = (1 << 16) - 1;
199      else
200      {
201        hs = historySize - 1;
202        hs |= (hs >> 1);
203        hs |= (hs >> 2);
204        hs |= (hs >> 4);
205        hs |= (hs >> 8);
206        hs >>= 1;
207        hs |= 0xFFFF; /* don't change it! It's required for Deflate */
208        if (hs > (1 << 24))
209        {
210          if (p->numHashBytes == 3)
211            hs = (1 << 24) - 1;
212          else
213            hs >>= 1;
214        }
215      }
216      p->hashMask = hs;
217      hs++;
218      if (p->numHashBytes > 2) p->fixedHashSize += kHash2Size;
219      if (p->numHashBytes > 3) p->fixedHashSize += kHash3Size;
220      if (p->numHashBytes > 4) p->fixedHashSize += kHash4Size;
221      hs += p->fixedHashSize;
222    }
223
224    {
225      UInt32 prevSize = p->hashSizeSum + p->numSons;
226      UInt32 newSize;
227      p->historySize = historySize;
228      p->hashSizeSum = hs;
229      p->cyclicBufferSize = newCyclicBufferSize;
230      p->numSons = (p->btMode ? newCyclicBufferSize * 2 : newCyclicBufferSize);
231      newSize = p->hashSizeSum + p->numSons;
232      if (p->hash != 0 && prevSize == newSize)
233        return 1;
234      MatchFinder_FreeThisClassMemory(p, alloc);
235      p->hash = AllocRefs(newSize, alloc);
236      if (p->hash != 0)
237      {
238        p->son = p->hash + p->hashSizeSum;
239        return 1;
240      }
241    }
242  }
243  MatchFinder_Free(p, alloc);
244  return 0;
245}
246
247static void MatchFinder_SetLimits(CMatchFinder *p)
248{
249  UInt32 limit = kMaxValForNormalize - p->pos;
250  UInt32 limit2 = p->cyclicBufferSize - p->cyclicBufferPos;
251  if (limit2 < limit)
252    limit = limit2;
253  limit2 = p->streamPos - p->pos;
254  if (limit2 <= p->keepSizeAfter)
255  {
256    if (limit2 > 0)
257      limit2 = 1;
258  }
259  else
260    limit2 -= p->keepSizeAfter;
261  if (limit2 < limit)
262    limit = limit2;
263  {
264    UInt32 lenLimit = p->streamPos - p->pos;
265    if (lenLimit > p->matchMaxLen)
266      lenLimit = p->matchMaxLen;
267    p->lenLimit = lenLimit;
268  }
269  p->posLimit = p->pos + limit;
270}
271
272void MatchFinder_Init(CMatchFinder *p)
273{
274  UInt32 i;
275  for (i = 0; i < p->hashSizeSum; i++)
276    p->hash[i] = kEmptyHashValue;
277  p->cyclicBufferPos = 0;
278  p->buffer = p->bufferBase;
279  p->pos = p->streamPos = p->cyclicBufferSize;
280  p->result = SZ_OK;
281  p->streamEndWasReached = 0;
282  MatchFinder_ReadBlock(p);
283  MatchFinder_SetLimits(p);
284}
285
286static UInt32 MatchFinder_GetSubValue(CMatchFinder *p)
287{
288  return (p->pos - p->historySize - 1) & kNormalizeMask;
289}
290
291void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, UInt32 numItems)
292{
293  UInt32 i;
294  for (i = 0; i < numItems; i++)
295  {
296    UInt32 value = items[i];
297    if (value <= subValue)
298      value = kEmptyHashValue;
299    else
300      value -= subValue;
301    items[i] = value;
302  }
303}
304
305static void MatchFinder_Normalize(CMatchFinder *p)
306{
307  UInt32 subValue = MatchFinder_GetSubValue(p);
308  MatchFinder_Normalize3(subValue, p->hash, p->hashSizeSum + p->numSons);
309  MatchFinder_ReduceOffsets(p, subValue);
310}
311
312static void MatchFinder_CheckLimits(CMatchFinder *p)
313{
314  if (p->pos == kMaxValForNormalize)
315    MatchFinder_Normalize(p);
316  if (!p->streamEndWasReached && p->keepSizeAfter == p->streamPos - p->pos)
317    MatchFinder_CheckAndMoveAndRead(p);
318  if (p->cyclicBufferPos == p->cyclicBufferSize)
319    p->cyclicBufferPos = 0;
320  MatchFinder_SetLimits(p);
321}
322
323static UInt32 * Hc_GetMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
324    UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue,
325    UInt32 *distances, UInt32 maxLen)
326{
327  son[_cyclicBufferPos] = curMatch;
328  for (;;)
329  {
330    UInt32 delta = pos - curMatch;
331    if (cutValue-- == 0 || delta >= _cyclicBufferSize)
332      return distances;
333    {
334      const Byte *pb = cur - delta;
335      curMatch = son[_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)];
336      if (pb[maxLen] == cur[maxLen] && *pb == *cur)
337      {
338        UInt32 len = 0;
339        while (++len != lenLimit)
340          if (pb[len] != cur[len])
341            break;
342        if (maxLen < len)
343        {
344          *distances++ = maxLen = len;
345          *distances++ = delta - 1;
346          if (len == lenLimit)
347            return distances;
348        }
349      }
350    }
351  }
352}
353
354UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
355    UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue,
356    UInt32 *distances, UInt32 maxLen)
357{
358  CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;
359  CLzRef *ptr1 = son + (_cyclicBufferPos << 1);
360  UInt32 len0 = 0, len1 = 0;
361  for (;;)
362  {
363    UInt32 delta = pos - curMatch;
364    if (cutValue-- == 0 || delta >= _cyclicBufferSize)
365    {
366      *ptr0 = *ptr1 = kEmptyHashValue;
367      return distances;
368    }
369    {
370      CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);
371      const Byte *pb = cur - delta;
372      UInt32 len = (len0 < len1 ? len0 : len1);
373      if (pb[len] == cur[len])
374      {
375        if (++len != lenLimit && pb[len] == cur[len])
376          while (++len != lenLimit)
377            if (pb[len] != cur[len])
378              break;
379        if (maxLen < len)
380        {
381          *distances++ = maxLen = len;
382          *distances++ = delta - 1;
383          if (len == lenLimit)
384          {
385            *ptr1 = pair[0];
386            *ptr0 = pair[1];
387            return distances;
388          }
389        }
390      }
391      if (pb[len] < cur[len])
392      {
393        *ptr1 = curMatch;
394        ptr1 = pair + 1;
395        curMatch = *ptr1;
396        len1 = len;
397      }
398      else
399      {
400        *ptr0 = curMatch;
401        ptr0 = pair;
402        curMatch = *ptr0;
403        len0 = len;
404      }
405    }
406  }
407}
408
409static void SkipMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
410    UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue)
411{
412  CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;
413  CLzRef *ptr1 = son + (_cyclicBufferPos << 1);
414  UInt32 len0 = 0, len1 = 0;
415  for (;;)
416  {
417    UInt32 delta = pos - curMatch;
418    if (cutValue-- == 0 || delta >= _cyclicBufferSize)
419    {
420      *ptr0 = *ptr1 = kEmptyHashValue;
421      return;
422    }
423    {
424      CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);
425      const Byte *pb = cur - delta;
426      UInt32 len = (len0 < len1 ? len0 : len1);
427      if (pb[len] == cur[len])
428      {
429        while (++len != lenLimit)
430          if (pb[len] != cur[len])
431            break;
432        {
433          if (len == lenLimit)
434          {
435            *ptr1 = pair[0];
436            *ptr0 = pair[1];
437            return;
438          }
439        }
440      }
441      if (pb[len] < cur[len])
442      {
443        *ptr1 = curMatch;
444        ptr1 = pair + 1;
445        curMatch = *ptr1;
446        len1 = len;
447      }
448      else
449      {
450        *ptr0 = curMatch;
451        ptr0 = pair;
452        curMatch = *ptr0;
453        len0 = len;
454      }
455    }
456  }
457}
458
459#define MOVE_POS \
460  ++p->cyclicBufferPos; \
461  p->buffer++; \
462  if (++p->pos == p->posLimit) MatchFinder_CheckLimits(p);
463
464#define MOVE_POS_RET MOVE_POS return offset;
465
466static void MatchFinder_MovePos(CMatchFinder *p) { MOVE_POS; }
467
468#define GET_MATCHES_HEADER2(minLen, ret_op) \
469  UInt32 lenLimit; UInt32 hashValue; const Byte *cur; UInt32 curMatch; \
470  lenLimit = p->lenLimit; { if (lenLimit < minLen) { MatchFinder_MovePos(p); ret_op; }} \
471  cur = p->buffer;
472
473#define GET_MATCHES_HEADER(minLen) GET_MATCHES_HEADER2(minLen, return 0)
474#define SKIP_HEADER(minLen)        GET_MATCHES_HEADER2(minLen, continue)
475
476#define MF_PARAMS(p) p->pos, p->buffer, p->son, p->cyclicBufferPos, p->cyclicBufferSize, p->cutValue
477
478#define GET_MATCHES_FOOTER(offset, maxLen) \
479  offset = (UInt32)(GetMatchesSpec1(lenLimit, curMatch, MF_PARAMS(p), \
480  distances + offset, maxLen) - distances); MOVE_POS_RET;
481
482#define SKIP_FOOTER \
483  SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); MOVE_POS;
484
485static UInt32 Bt2_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
486{
487  UInt32 offset;
488  GET_MATCHES_HEADER(2)
489  HASH2_CALC;
490  curMatch = p->hash[hashValue];
491  p->hash[hashValue] = p->pos;
492  offset = 0;
493  GET_MATCHES_FOOTER(offset, 1)
494}
495
496UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
497{
498  UInt32 offset;
499  GET_MATCHES_HEADER(3)
500  HASH_ZIP_CALC;
501  curMatch = p->hash[hashValue];
502  p->hash[hashValue] = p->pos;
503  offset = 0;
504  GET_MATCHES_FOOTER(offset, 2)
505}
506
507static UInt32 Bt3_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
508{
509  UInt32 hash2Value, delta2, maxLen, offset;
510  GET_MATCHES_HEADER(3)
511
512  HASH3_CALC;
513
514  delta2 = p->pos - p->hash[hash2Value];
515  curMatch = p->hash[kFix3HashSize + hashValue];
516
517  p->hash[hash2Value] =
518  p->hash[kFix3HashSize + hashValue] = p->pos;
519
520
521  maxLen = 2;
522  offset = 0;
523  if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
524  {
525    for (; maxLen != lenLimit; maxLen++)
526      if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
527        break;
528    distances[0] = maxLen;
529    distances[1] = delta2 - 1;
530    offset = 2;
531    if (maxLen == lenLimit)
532    {
533      SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p));
534      MOVE_POS_RET;
535    }
536  }
537  GET_MATCHES_FOOTER(offset, maxLen)
538}
539
540static UInt32 Bt4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
541{
542  UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset;
543  GET_MATCHES_HEADER(4)
544
545  HASH4_CALC;
546
547  delta2 = p->pos - p->hash[                hash2Value];
548  delta3 = p->pos - p->hash[kFix3HashSize + hash3Value];
549  curMatch = p->hash[kFix4HashSize + hashValue];
550
551  p->hash[                hash2Value] =
552  p->hash[kFix3HashSize + hash3Value] =
553  p->hash[kFix4HashSize + hashValue] = p->pos;
554
555  maxLen = 1;
556  offset = 0;
557  if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
558  {
559    distances[0] = maxLen = 2;
560    distances[1] = delta2 - 1;
561    offset = 2;
562  }
563  if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur)
564  {
565    maxLen = 3;
566    distances[offset + 1] = delta3 - 1;
567    offset += 2;
568    delta2 = delta3;
569  }
570  if (offset != 0)
571  {
572    for (; maxLen != lenLimit; maxLen++)
573      if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
574        break;
575    distances[offset - 2] = maxLen;
576    if (maxLen == lenLimit)
577    {
578      SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p));
579      MOVE_POS_RET;
580    }
581  }
582  if (maxLen < 3)
583    maxLen = 3;
584  GET_MATCHES_FOOTER(offset, maxLen)
585}
586
587static UInt32 Hc4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
588{
589  UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset;
590  GET_MATCHES_HEADER(4)
591
592  HASH4_CALC;
593
594  delta2 = p->pos - p->hash[                hash2Value];
595  delta3 = p->pos - p->hash[kFix3HashSize + hash3Value];
596  curMatch = p->hash[kFix4HashSize + hashValue];
597
598  p->hash[                hash2Value] =
599  p->hash[kFix3HashSize + hash3Value] =
600  p->hash[kFix4HashSize + hashValue] = p->pos;
601
602  maxLen = 1;
603  offset = 0;
604  if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
605  {
606    distances[0] = maxLen = 2;
607    distances[1] = delta2 - 1;
608    offset = 2;
609  }
610  if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur)
611  {
612    maxLen = 3;
613    distances[offset + 1] = delta3 - 1;
614    offset += 2;
615    delta2 = delta3;
616  }
617  if (offset != 0)
618  {
619    for (; maxLen != lenLimit; maxLen++)
620      if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
621        break;
622    distances[offset - 2] = maxLen;
623    if (maxLen == lenLimit)
624    {
625      p->son[p->cyclicBufferPos] = curMatch;
626      MOVE_POS_RET;
627    }
628  }
629  if (maxLen < 3)
630    maxLen = 3;
631  offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p),
632    distances + offset, maxLen) - (distances));
633  MOVE_POS_RET
634}
635
636UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
637{
638  UInt32 offset;
639  GET_MATCHES_HEADER(3)
640  HASH_ZIP_CALC;
641  curMatch = p->hash[hashValue];
642  p->hash[hashValue] = p->pos;
643  offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p),
644    distances, 2) - (distances));
645  MOVE_POS_RET
646}
647
648static void Bt2_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
649{
650  do
651  {
652    SKIP_HEADER(2)
653    HASH2_CALC;
654    curMatch = p->hash[hashValue];
655    p->hash[hashValue] = p->pos;
656    SKIP_FOOTER
657  }
658  while (--num != 0);
659}
660
661void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
662{
663  do
664  {
665    SKIP_HEADER(3)
666    HASH_ZIP_CALC;
667    curMatch = p->hash[hashValue];
668    p->hash[hashValue] = p->pos;
669    SKIP_FOOTER
670  }
671  while (--num != 0);
672}
673
674static void Bt3_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
675{
676  do
677  {
678    UInt32 hash2Value;
679    SKIP_HEADER(3)
680    HASH3_CALC;
681    curMatch = p->hash[kFix3HashSize + hashValue];
682    p->hash[hash2Value] =
683    p->hash[kFix3HashSize + hashValue] = p->pos;
684    SKIP_FOOTER
685  }
686  while (--num != 0);
687}
688
689static void Bt4_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
690{
691  do
692  {
693    UInt32 hash2Value, hash3Value;
694    SKIP_HEADER(4)
695    HASH4_CALC;
696    curMatch = p->hash[kFix4HashSize + hashValue];
697    p->hash[                hash2Value] =
698    p->hash[kFix3HashSize + hash3Value] = p->pos;
699    p->hash[kFix4HashSize + hashValue] = p->pos;
700    SKIP_FOOTER
701  }
702  while (--num != 0);
703}
704
705static void Hc4_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
706{
707  do
708  {
709    UInt32 hash2Value, hash3Value;
710    SKIP_HEADER(4)
711    HASH4_CALC;
712    curMatch = p->hash[kFix4HashSize + hashValue];
713    p->hash[                hash2Value] =
714    p->hash[kFix3HashSize + hash3Value] =
715    p->hash[kFix4HashSize + hashValue] = p->pos;
716    p->son[p->cyclicBufferPos] = curMatch;
717    MOVE_POS
718  }
719  while (--num != 0);
720}
721
722void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
723{
724  do
725  {
726    SKIP_HEADER(3)
727    HASH_ZIP_CALC;
728    curMatch = p->hash[hashValue];
729    p->hash[hashValue] = p->pos;
730    p->son[p->cyclicBufferPos] = curMatch;
731    MOVE_POS
732  }
733  while (--num != 0);
734}
735
736void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder *vTable)
737{
738  vTable->Init = (Mf_Init_Func)MatchFinder_Init;
739  vTable->GetIndexByte = (Mf_GetIndexByte_Func)MatchFinder_GetIndexByte;
740  vTable->GetNumAvailableBytes = (Mf_GetNumAvailableBytes_Func)MatchFinder_GetNumAvailableBytes;
741  vTable->GetPointerToCurrentPos = (Mf_GetPointerToCurrentPos_Func)MatchFinder_GetPointerToCurrentPos;
742  if (!p->btMode)
743  {
744    vTable->GetMatches = (Mf_GetMatches_Func)Hc4_MatchFinder_GetMatches;
745    vTable->Skip = (Mf_Skip_Func)Hc4_MatchFinder_Skip;
746  }
747  else if (p->numHashBytes == 2)
748  {
749    vTable->GetMatches = (Mf_GetMatches_Func)Bt2_MatchFinder_GetMatches;
750    vTable->Skip = (Mf_Skip_Func)Bt2_MatchFinder_Skip;
751  }
752  else if (p->numHashBytes == 3)
753  {
754    vTable->GetMatches = (Mf_GetMatches_Func)Bt3_MatchFinder_GetMatches;
755    vTable->Skip = (Mf_Skip_Func)Bt3_MatchFinder_Skip;
756  }
757  else
758  {
759    vTable->GetMatches = (Mf_GetMatches_Func)Bt4_MatchFinder_GetMatches;
760    vTable->Skip = (Mf_Skip_Func)Bt4_MatchFinder_Skip;
761  }
762}
763