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99 pmbaty 1
/* LzFind.c -- Match finder for LZ algorithms
2
2008-10-04 : Igor Pavlov : Public domain */
3
 
4
#include <string.h>
5
 
6
#include "LzFind.h"
7
#include "LzHash.h"
8
 
9
#define kEmptyHashValue 0
10
#define kMaxValForNormalize ((UInt32)0xFFFFFFFF)
11
#define kNormalizeStepMin (1u << 10) /* it must be power of 2 */ /*MAB 1u */
12
#define kNormalizeMask (~(kNormalizeStepMin - 1))
13
#define kMaxHistorySize ((UInt32)3 << 30)
14
 
15
#define kStartMaxLen 3
16
 
17
static void LzInWindow_Free(CMatchFinder *p, ISzAlloc *alloc)
18
{
19
  if (!p->directInput)
20
  {
21
    alloc->Free(alloc, p->bufferBase);
22
    p->bufferBase = 0;
23
  }
24
}
25
 
26
/* keepSizeBefore + keepSizeAfter + keepSizeReserv must be < 4G) */
27
 
28
static int LzInWindow_Create(CMatchFinder *p, UInt32 keepSizeReserv, ISzAlloc *alloc)
29
{
30
  UInt32 blockSize = p->keepSizeBefore + p->keepSizeAfter + keepSizeReserv;
31
  if (p->directInput)
32
  {
33
    p->blockSize = blockSize;
34
    return 1;
35
  }
36
  if (p->bufferBase == 0 || p->blockSize != blockSize)
37
  {
38
    LzInWindow_Free(p, alloc);
39
    p->blockSize = blockSize;
40
    p->bufferBase = (Byte *)alloc->Alloc(alloc, (size_t)blockSize);
41
  }
42
  return (p->bufferBase != 0);
43
}
44
 
45
Byte *MatchFinder_GetPointerToCurrentPos(CMatchFinder *p) { return p->buffer; }
46
 
47
/*MAB: static added, index replaced by idx to avoid shadowing a global variable */
48
static
49
Byte MatchFinder_GetIndexByte(CMatchFinder *p, Int32 idx) { return p->buffer[idx]; }
50
 
51
/*MAB: static added */
52
static
53
UInt32 MatchFinder_GetNumAvailableBytes(CMatchFinder *p) { return p->streamPos - p->pos; }
54
 
55
void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue)
56
{
57
  p->posLimit -= subValue;
58
  p->pos -= subValue;
59
  p->streamPos -= subValue;
60
}
61
 
62
static void MatchFinder_ReadBlock(CMatchFinder *p)
63
{
64
  if (p->streamEndWasReached || p->result != SZ_OK)
65
    return;
66
  for (;;)
67
  {
68
    Byte *dest = p->buffer + (p->streamPos - p->pos);
69
    size_t size = (size_t)(p->bufferBase + p->blockSize - dest);
70
    if (size == 0)
71
      return;
72
    p->result = p->stream->Read(p->stream, dest, &size);
73
    if (p->result != SZ_OK)
74
      return;
75
    if (size == 0)
76
    {
77
      p->streamEndWasReached = 1;
78
      return;
79
    }
80
    p->streamPos += (UInt32)size;
81
    if (p->streamPos - p->pos > p->keepSizeAfter)
82
      return;
83
  }
84
}
85
 
86
void MatchFinder_MoveBlock(CMatchFinder *p)
87
{
88
  memmove(p->bufferBase,
89
    p->buffer - p->keepSizeBefore,
90
    (size_t)(p->streamPos - p->pos + p->keepSizeBefore));
91
  p->buffer = p->bufferBase + p->keepSizeBefore;
92
}
93
 
94
int MatchFinder_NeedMove(CMatchFinder *p)
95
{
96
  /* if (p->streamEndWasReached) return 0; */
97
  return ((size_t)(p->bufferBase + p->blockSize - p->buffer) <= p->keepSizeAfter);
98
}
99
 
100
void MatchFinder_ReadIfRequired(CMatchFinder *p)
101
{
102
  if (p->streamEndWasReached)
103
    return;
104
  if (p->keepSizeAfter >= p->streamPos - p->pos)
105
    MatchFinder_ReadBlock(p);
106
}
107
 
108
static void MatchFinder_CheckAndMoveAndRead(CMatchFinder *p)
109
{
110
  if (MatchFinder_NeedMove(p))
111
    MatchFinder_MoveBlock(p);
112
  MatchFinder_ReadBlock(p);
113
}
114
 
115
static void MatchFinder_SetDefaultSettings(CMatchFinder *p)
116
{
117
  p->cutValue = 32;
118
  p->btMode = 1;
119
  p->numHashBytes = 4;
120
  /* p->skipModeBits = 0; */
121
  p->directInput = 0;
122
  p->bigHash = 0;
123
}
124
 
125
#define kCrcPoly 0xEDB88320
126
 
127
void MatchFinder_Construct(CMatchFinder *p)
128
{
129
  UInt32 i;
130
  p->bufferBase = 0;
131
  p->directInput = 0;
132
  p->hash = 0;
133
  MatchFinder_SetDefaultSettings(p);
134
 
135
  for (i = 0; i < 256; i++)
136
  {
137
    UInt32 r = i;
138
    int j;
139
    for (j = 0; j < 8; j++)
140
      r = (r >> 1) ^ (kCrcPoly & ~((r & 1) - 1));
141
    p->crc[i] = r;
142
  }
143
}
144
 
145
static void MatchFinder_FreeThisClassMemory(CMatchFinder *p, ISzAlloc *alloc)
146
{
147
  alloc->Free(alloc, p->hash);
148
  p->hash = 0;
149
}
150
 
151
void MatchFinder_Free(CMatchFinder *p, ISzAlloc *alloc)
152
{
153
  MatchFinder_FreeThisClassMemory(p, alloc);
154
  LzInWindow_Free(p, alloc);
155
}
156
 
157
static CLzRef* AllocRefs(UInt32 num, ISzAlloc *alloc)
158
{
159
  size_t sizeInBytes = (size_t)num * sizeof(CLzRef);
160
  if (sizeInBytes / sizeof(CLzRef) != num)
161
    return 0;
162
  return (CLzRef *)alloc->Alloc(alloc, sizeInBytes);
163
}
164
 
165
int MatchFinder_Create(CMatchFinder *p, UInt32 historySize,
166
    UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter,
167
    ISzAlloc *alloc)
168
{
169
  UInt32 sizeReserv;
170
  if (historySize > kMaxHistorySize)
171
  {
172
    MatchFinder_Free(p, alloc);
173
    return 0;
174
  }
175
  sizeReserv = historySize >> 1;
176
  if (historySize > ((UInt32)2 << 30))
177
    sizeReserv = historySize >> 2;
178
  sizeReserv += (keepAddBufferBefore + matchMaxLen + keepAddBufferAfter) / 2 + (1 << 19);
179
 
180
  p->keepSizeBefore = historySize + keepAddBufferBefore + 1;
181
  p->keepSizeAfter = matchMaxLen + keepAddBufferAfter;
182
  /* we need one additional byte, since we use MoveBlock after pos++ and before dictionary using */
183
  if (LzInWindow_Create(p, sizeReserv, alloc))
184
  {
185
    UInt32 newCyclicBufferSize = (historySize /* >> p->skipModeBits */) + 1;
186
    UInt32 hs;
187
    p->matchMaxLen = matchMaxLen;
188
    {
189
      p->fixedHashSize = 0;
190
      if (p->numHashBytes == 2)
191
        hs = (1 << 16) - 1;
192
      else
193
      {
194
        hs = historySize - 1;
195
        hs |= (hs >> 1);
196
        hs |= (hs >> 2);
197
        hs |= (hs >> 4);
198
        hs |= (hs >> 8);
199
        hs >>= 1;
200
        /* hs >>= p->skipModeBits; */
201
        hs |= 0xFFFF; /* don't change it! It's required for Deflate */
202
        if (hs > (1 << 24))
203
        {
204
          if (p->numHashBytes == 3)
205
            hs = (1 << 24) - 1;
206
          else
207
            hs >>= 1;
208
        }
209
      }
210
      p->hashMask = hs;
211
      hs++;
212
      if (p->numHashBytes > 2) p->fixedHashSize += kHash2Size;
213
      if (p->numHashBytes > 3) p->fixedHashSize += kHash3Size;
214
      if (p->numHashBytes > 4) p->fixedHashSize += kHash4Size;
215
      hs += p->fixedHashSize;
216
    }
217
 
218
    {
219
      UInt32 prevSize = p->hashSizeSum + p->numSons;
220
      UInt32 newSize;
221
      p->historySize = historySize;
222
      p->hashSizeSum = hs;
223
      p->cyclicBufferSize = newCyclicBufferSize;
224
      p->numSons = (p->btMode ? newCyclicBufferSize * 2 : newCyclicBufferSize);
225
      newSize = p->hashSizeSum + p->numSons;
226
      if (p->hash != 0 && prevSize == newSize)
227
        return 1;
228
      MatchFinder_FreeThisClassMemory(p, alloc);
229
      p->hash = AllocRefs(newSize, alloc);
230
      if (p->hash != 0)
231
      {
232
        p->son = p->hash + p->hashSizeSum;
233
        return 1;
234
      }
235
    }
236
  }
237
  MatchFinder_Free(p, alloc);
238
  return 0;
239
}
240
 
241
static void MatchFinder_SetLimits(CMatchFinder *p)
242
{
243
  UInt32 limit = kMaxValForNormalize - p->pos;
244
  UInt32 limit2 = p->cyclicBufferSize - p->cyclicBufferPos;
245
  if (limit2 < limit)
246
    limit = limit2;
247
  limit2 = p->streamPos - p->pos;
248
  if (limit2 <= p->keepSizeAfter)
249
  {
250
    if (limit2 > 0)
251
      limit2 = 1;
252
  }
253
  else
254
    limit2 -= p->keepSizeAfter;
255
  if (limit2 < limit)
256
    limit = limit2;
257
  {
258
    UInt32 lenLimit = p->streamPos - p->pos;
259
    if (lenLimit > p->matchMaxLen)
260
      lenLimit = p->matchMaxLen;
261
    p->lenLimit = lenLimit;
262
  }
263
  p->posLimit = p->pos + limit;
264
}
265
 
266
void MatchFinder_Init(CMatchFinder *p)
267
{
268
  UInt32 i;
269
  for (i = 0; i < p->hashSizeSum; i++)
270
    p->hash[i] = kEmptyHashValue;
271
  p->cyclicBufferPos = 0;
272
  p->buffer = p->bufferBase;
273
  p->pos = p->streamPos = p->cyclicBufferSize;
274
  p->result = SZ_OK;
275
  p->streamEndWasReached = 0;
276
  MatchFinder_ReadBlock(p);
277
  MatchFinder_SetLimits(p);
278
}
279
 
280
static UInt32 MatchFinder_GetSubValue(CMatchFinder *p)
281
{
282
  return (p->pos - p->historySize - 1) & kNormalizeMask;
283
}
284
 
285
void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, UInt32 numItems)
286
{
287
  UInt32 i;
288
  for (i = 0; i < numItems; i++)
289
  {
290
    UInt32 value = items[i];
291
    if (value <= subValue)
292
      value = kEmptyHashValue;
293
    else
294
      value -= subValue;
295
    items[i] = value;
296
  }
297
}
298
 
299
static void MatchFinder_Normalize(CMatchFinder *p)
300
{
301
  UInt32 subValue = MatchFinder_GetSubValue(p);
302
  MatchFinder_Normalize3(subValue, p->hash, p->hashSizeSum + p->numSons);
303
  MatchFinder_ReduceOffsets(p, subValue);
304
}
305
 
306
static void MatchFinder_CheckLimits(CMatchFinder *p)
307
{
308
  if (p->pos == kMaxValForNormalize)
309
    MatchFinder_Normalize(p);
310
 
311
  if (!p->streamEndWasReached && p->keepSizeAfter == p->streamPos - p->pos)
312
    MatchFinder_CheckAndMoveAndRead(p);
313
  if (p->cyclicBufferPos == p->cyclicBufferSize)
314
    p->cyclicBufferPos = 0;
315
  MatchFinder_SetLimits(p);
316
}
317
 
318
static UInt32 * Hc_GetMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
319
    UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue,
320
    UInt32 *distances, UInt32 maxLen)
321
{
322
  son[_cyclicBufferPos] = curMatch;
323
  for (;;)
324
  {
325
    UInt32 delta = pos - curMatch;
326
    if (cutValue-- == 0 || delta >= _cyclicBufferSize)
327
      return distances;
328
    {
329
      const Byte *pb = cur - delta;
330
      curMatch = son[_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)];
331
      if (pb[maxLen] == cur[maxLen] && *pb == *cur)
332
      {
333
        UInt32 len = 0;
334
        while (++len != lenLimit)
335
          if (pb[len] != cur[len])
336
            break;
337
        if (maxLen < len)
338
        {
339
          *distances++ = maxLen = len;
340
          *distances++ = delta - 1;
341
          if (len == lenLimit)
342
            return distances;
343
        }
344
      }
345
    }
346
  }
347
}
348
 
349
UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
350
    UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue,
351
    UInt32 *distances, UInt32 maxLen)
352
{
353
  CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;
354
  CLzRef *ptr1 = son + (_cyclicBufferPos << 1);
355
  UInt32 len0 = 0, len1 = 0;
356
  for (;;)
357
  {
358
    UInt32 delta = pos - curMatch;
359
    if (cutValue-- == 0 || delta >= _cyclicBufferSize)
360
    {
361
      *ptr0 = *ptr1 = kEmptyHashValue;
362
      return distances;
363
    }
364
    {
365
      CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);
366
      const Byte *pb = cur - delta;
367
      UInt32 len = (len0 < len1 ? len0 : len1);
368
      if (pb[len] == cur[len])
369
      {
370
        if (++len != lenLimit && pb[len] == cur[len])
371
          while (++len != lenLimit)
372
            if (pb[len] != cur[len])
373
              break;
374
        if (maxLen < len)
375
        {
376
          *distances++ = maxLen = len;
377
          *distances++ = delta - 1;
378
          if (len == lenLimit)
379
          {
380
            *ptr1 = pair[0];
381
            *ptr0 = pair[1];
382
            return distances;
383
          }
384
        }
385
      }
386
      if (pb[len] < cur[len])
387
      {
388
        *ptr1 = curMatch;
389
        ptr1 = pair + 1;
390
        curMatch = *ptr1;
391
        len1 = len;
392
      }
393
      else
394
      {
395
        *ptr0 = curMatch;
396
        ptr0 = pair;
397
        curMatch = *ptr0;
398
        len0 = len;
399
      }
400
    }
401
  }
402
}
403
 
404
static void SkipMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
405
    UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue)
406
{
407
  CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;
408
  CLzRef *ptr1 = son + (_cyclicBufferPos << 1);
409
  UInt32 len0 = 0, len1 = 0;
410
  for (;;)
411
  {
412
    UInt32 delta = pos - curMatch;
413
    if (cutValue-- == 0 || delta >= _cyclicBufferSize)
414
    {
415
      *ptr0 = *ptr1 = kEmptyHashValue;
416
      return;
417
    }
418
    {
419
      CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);
420
      const Byte *pb = cur - delta;
421
      UInt32 len = (len0 < len1 ? len0 : len1);
422
      if (pb[len] == cur[len])
423
      {
424
        while (++len != lenLimit)
425
          if (pb[len] != cur[len])
426
            break;
427
        {
428
          if (len == lenLimit)
429
          {
430
            *ptr1 = pair[0];
431
            *ptr0 = pair[1];
432
            return;
433
          }
434
        }
435
      }
436
      if (pb[len] < cur[len])
437
      {
438
        *ptr1 = curMatch;
439
        ptr1 = pair + 1;
440
        curMatch = *ptr1;
441
        len1 = len;
442
      }
443
      else
444
      {
445
        *ptr0 = curMatch;
446
        ptr0 = pair;
447
        curMatch = *ptr0;
448
        len0 = len;
449
      }
450
    }
451
  }
452
}
453
 
454
#define MOVE_POS \
455
  ++p->cyclicBufferPos; \
456
  p->buffer++; \
457
  if (++p->pos == p->posLimit) MatchFinder_CheckLimits(p);
458
 
459
#define MOVE_POS_RET MOVE_POS return offset;
460
 
461
static void MatchFinder_MovePos(CMatchFinder *p) { MOVE_POS; }
462
 
463
#define GET_MATCHES_HEADER2(minLen, ret_op) \
464
  UInt32 lenLimit; UInt32 hashValue; const Byte *cur; UInt32 curMatch; \
465
  lenLimit = p->lenLimit; { if (lenLimit < minLen) { MatchFinder_MovePos(p); ret_op; }} \
466
  cur = p->buffer;
467
 
468
#define GET_MATCHES_HEADER(minLen) GET_MATCHES_HEADER2(minLen, return 0)
469
#define SKIP_HEADER(minLen)        GET_MATCHES_HEADER2(minLen, continue)
470
 
471
#define MF_PARAMS(p) p->pos, p->buffer, p->son, p->cyclicBufferPos, p->cyclicBufferSize, p->cutValue
472
 
473
#define GET_MATCHES_FOOTER(offset, maxLen) \
474
  offset = (UInt32)(GetMatchesSpec1(lenLimit, curMatch, MF_PARAMS(p), \
475
  distances + offset, maxLen) - distances); MOVE_POS_RET;
476
 
477
#define SKIP_FOOTER \
478
  SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); MOVE_POS;
479
 
480
static UInt32 Bt2_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
481
{
482
  UInt32 offset;
483
  GET_MATCHES_HEADER(2)
484
  HASH2_CALC;
485
  curMatch = p->hash[hashValue];
486
  p->hash[hashValue] = p->pos;
487
  offset = 0;
488
  GET_MATCHES_FOOTER(offset, 1)
489
}
490
 
491
UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
492
{
493
  UInt32 offset;
494
  GET_MATCHES_HEADER(3)
495
  HASH_ZIP_CALC;
496
  curMatch = p->hash[hashValue];
497
  p->hash[hashValue] = p->pos;
498
  offset = 0;
499
  GET_MATCHES_FOOTER(offset, 2)
500
}
501
 
502
static UInt32 Bt3_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
503
{
504
  UInt32 hash2Value, delta2, maxLen, offset;
505
  GET_MATCHES_HEADER(3)
506
 
507
  HASH3_CALC;
508
 
509
  delta2 = p->pos - p->hash[hash2Value];
510
  curMatch = p->hash[kFix3HashSize + hashValue];
511
 
512
  p->hash[hash2Value] =
513
  p->hash[kFix3HashSize + hashValue] = p->pos;
514
 
515
 
516
  maxLen = 2;
517
  offset = 0;
518
  if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
519
  {
520
    for (; maxLen != lenLimit; maxLen++)
521
      if (cur[(ptrdiff_t)maxLen - (ptrdiff_t)delta2] != cur[maxLen]) /*MAB second casts (ptrdiff_t)*/
522
        break;
523
    distances[0] = maxLen;
524
    distances[1] = delta2 - 1;
525
    offset = 2;
526
    if (maxLen == lenLimit)
527
    {
528
      SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p));
529
      MOVE_POS_RET;
530
    }
531
  }
532
  GET_MATCHES_FOOTER(offset, maxLen)
533
}
534
 
535
static UInt32 Bt4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
536
{
537
  UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset;
538
  GET_MATCHES_HEADER(4)
539
 
540
  HASH4_CALC;
541
 
542
  delta2 = p->pos - p->hash[                hash2Value];
543
  delta3 = p->pos - p->hash[kFix3HashSize + hash3Value];
544
  curMatch = p->hash[kFix4HashSize + hashValue];
545
 
546
  p->hash[                hash2Value] =
547
  p->hash[kFix3HashSize + hash3Value] =
548
  p->hash[kFix4HashSize + hashValue] = p->pos;
549
 
550
  maxLen = 1;
551
  offset = 0;
552
  if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
553
  {
554
    distances[0] = maxLen = 2;
555
    distances[1] = delta2 - 1;
556
    offset = 2;
557
  }
558
  if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur)
559
  {
560
    maxLen = 3;
561
    distances[offset + 1] = delta3 - 1;
562
    offset += 2;
563
    delta2 = delta3;
564
  }
565
  if (offset != 0)
566
  {
567
    for (; maxLen != lenLimit; maxLen++)
568
      if (cur[(ptrdiff_t)maxLen - (ptrdiff_t)delta2] != cur[maxLen]) /*MAB casts second (ptrdiff_t)*/
569
        break;
570
    distances[offset - 2] = maxLen;
571
    if (maxLen == lenLimit)
572
    {
573
      SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p));
574
      MOVE_POS_RET;
575
    }
576
  }
577
  if (maxLen < 3)
578
    maxLen = 3;
579
  GET_MATCHES_FOOTER(offset, maxLen)
580
}
581
 
582
static UInt32 Hc4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
583
{
584
  UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset;
585
  GET_MATCHES_HEADER(4)
586
 
587
  HASH4_CALC;
588
 
589
  delta2 = p->pos - p->hash[                hash2Value];
590
  delta3 = p->pos - p->hash[kFix3HashSize + hash3Value];
591
  curMatch = p->hash[kFix4HashSize + hashValue];
592
 
593
  p->hash[                hash2Value] =
594
  p->hash[kFix3HashSize + hash3Value] =
595
  p->hash[kFix4HashSize + hashValue] = p->pos;
596
 
597
  maxLen = 1;
598
  offset = 0;
599
  if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
600
  {
601
    distances[0] = maxLen = 2;
602
    distances[1] = delta2 - 1;
603
    offset = 2;
604
  }
605
  if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur)
606
  {
607
    maxLen = 3;
608
    distances[offset + 1] = delta3 - 1;
609
    offset += 2;
610
    delta2 = delta3;
611
  }
612
  if (offset != 0)
613
  {
614
    for (; maxLen != lenLimit; maxLen++)
615
      if (cur[(ptrdiff_t)maxLen - (ptrdiff_t)delta2] != cur[maxLen]) /*MAB casts second (ptrdiff_t) */
616
        break;
617
 
618
    distances[offset - 2] = maxLen;
619
    if (maxLen == lenLimit)
620
    {
621
      p->son[p->cyclicBufferPos] = curMatch;
622
      MOVE_POS_RET;
623
    }
624
  }
625
  if (maxLen < 3)
626
    maxLen = 3;
627
  offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p),
628
    distances + offset, maxLen) - (distances));
629
  MOVE_POS_RET
630
}
631
 
632
UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
633
{
634
  UInt32 offset;
635
  GET_MATCHES_HEADER(3)
636
  HASH_ZIP_CALC;
637
  curMatch = p->hash[hashValue];
638
  p->hash[hashValue] = p->pos;
639
  offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p),
640
    distances, 2) - (distances));
641
  MOVE_POS_RET
642
}
643
 
644
static void Bt2_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
645
{
646
  do
647
  {
648
    SKIP_HEADER(2)
649
    HASH2_CALC;
650
    curMatch = p->hash[hashValue];
651
    p->hash[hashValue] = p->pos;
652
    SKIP_FOOTER
653
  }
654
  while (--num != 0);
655
}
656
 
657
void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
658
{
659
  do
660
  {
661
    SKIP_HEADER(3)
662
    HASH_ZIP_CALC;
663
    curMatch = p->hash[hashValue];
664
    p->hash[hashValue] = p->pos;
665
    SKIP_FOOTER
666
  }
667
  while (--num != 0);
668
}
669
 
670
static void Bt3_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
671
{
672
  do
673
  {
674
    UInt32 hash2Value;
675
    SKIP_HEADER(3)
676
    HASH3_CALC;
677
    curMatch = p->hash[kFix3HashSize + hashValue];
678
    p->hash[hash2Value] =
679
    p->hash[kFix3HashSize + hashValue] = p->pos;
680
    SKIP_FOOTER
681
  }
682
  while (--num != 0);
683
}
684
 
685
static void Bt4_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] = p->pos;
695
    p->hash[kFix4HashSize + hashValue] = p->pos;
696
    SKIP_FOOTER
697
  }
698
  while (--num != 0);
699
}
700
 
701
static void Hc4_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
702
{
703
  do
704
  {
705
    UInt32 hash2Value, hash3Value;
706
    SKIP_HEADER(4)
707
    HASH4_CALC;
708
    curMatch = p->hash[kFix4HashSize + hashValue];
709
    p->hash[                hash2Value] =
710
    p->hash[kFix3HashSize + hash3Value] =
711
    p->hash[kFix4HashSize + hashValue] = p->pos;
712
    p->son[p->cyclicBufferPos] = curMatch;
713
    MOVE_POS
714
  }
715
  while (--num != 0);
716
}
717
 
718
void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
719
{
720
  do
721
  {
722
    SKIP_HEADER(3)
723
    HASH_ZIP_CALC;
724
    curMatch = p->hash[hashValue];
725
    p->hash[hashValue] = p->pos;
726
    p->son[p->cyclicBufferPos] = curMatch;
727
    MOVE_POS
728
  }
729
  while (--num != 0);
730
}
731
 
732
void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder *vTable)
733
{
734
  vTable->Init = (Mf_Init_Func)MatchFinder_Init;
735
  vTable->GetIndexByte = (Mf_GetIndexByte_Func)MatchFinder_GetIndexByte;
736
  vTable->GetNumAvailableBytes = (Mf_GetNumAvailableBytes_Func)MatchFinder_GetNumAvailableBytes;
737
  vTable->GetPointerToCurrentPos = (Mf_GetPointerToCurrentPos_Func)MatchFinder_GetPointerToCurrentPos;
738
  if (!p->btMode)
739
  {
740
    vTable->GetMatches = (Mf_GetMatches_Func)Hc4_MatchFinder_GetMatches;
741
    vTable->Skip = (Mf_Skip_Func)Hc4_MatchFinder_Skip;
742
  }
743
  else if (p->numHashBytes == 2)
744
  {
745
    vTable->GetMatches = (Mf_GetMatches_Func)Bt2_MatchFinder_GetMatches;
746
    vTable->Skip = (Mf_Skip_Func)Bt2_MatchFinder_Skip;
747
  }
748
  else if (p->numHashBytes == 3)
749
  {
750
    vTable->GetMatches = (Mf_GetMatches_Func)Bt3_MatchFinder_GetMatches;
751
    vTable->Skip = (Mf_Skip_Func)Bt3_MatchFinder_Skip;
752
  }
753
  else
754
  {
755
    vTable->GetMatches = (Mf_GetMatches_Func)Bt4_MatchFinder_GetMatches;
756
    vTable->Skip = (Mf_Skip_Func)Bt4_MatchFinder_Skip;
757
  }
758
}