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comparison src/win32/7zip/7z/C/LzFind.c @ 1:f9f4f1b99eed

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importing src directory
author Robert McIntyre <rlm@mit.edu>
date Sat, 03 Mar 2012 10:31:27 -0600
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0:8ced16adf2e1 1:f9f4f1b99eed
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 (1 << 10) /* it must be power of 2 */
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 Byte MatchFinder_GetIndexByte(CMatchFinder *p, Int32 index) { return p->buffer[index]; }
47
48 UInt32 MatchFinder_GetNumAvailableBytes(CMatchFinder *p) { return p->streamPos - p->pos; }
49
50 void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue)
51 {
52 p->posLimit -= subValue;
53 p->pos -= subValue;
54 p->streamPos -= subValue;
55 }
56
57 static void MatchFinder_ReadBlock(CMatchFinder *p)
58 {
59 if (p->streamEndWasReached || p->result != SZ_OK)
60 return;
61 for (;;)
62 {
63 Byte *dest = p->buffer + (p->streamPos - p->pos);
64 size_t size = (p->bufferBase + p->blockSize - dest);
65 if (size == 0)
66 return;
67 p->result = p->stream->Read(p->stream, dest, &size);
68 if (p->result != SZ_OK)
69 return;
70 if (size == 0)
71 {
72 p->streamEndWasReached = 1;
73 return;
74 }
75 p->streamPos += (UInt32)size;
76 if (p->streamPos - p->pos > p->keepSizeAfter)
77 return;
78 }
79 }
80
81 void MatchFinder_MoveBlock(CMatchFinder *p)
82 {
83 memmove(p->bufferBase,
84 p->buffer - p->keepSizeBefore,
85 (size_t)(p->streamPos - p->pos + p->keepSizeBefore));
86 p->buffer = p->bufferBase + p->keepSizeBefore;
87 }
88
89 int MatchFinder_NeedMove(CMatchFinder *p)
90 {
91 /* if (p->streamEndWasReached) return 0; */
92 return ((size_t)(p->bufferBase + p->blockSize - p->buffer) <= p->keepSizeAfter);
93 }
94
95 void MatchFinder_ReadIfRequired(CMatchFinder *p)
96 {
97 if (p->streamEndWasReached)
98 return;
99 if (p->keepSizeAfter >= p->streamPos - p->pos)
100 MatchFinder_ReadBlock(p);
101 }
102
103 static void MatchFinder_CheckAndMoveAndRead(CMatchFinder *p)
104 {
105 if (MatchFinder_NeedMove(p))
106 MatchFinder_MoveBlock(p);
107 MatchFinder_ReadBlock(p);
108 }
109
110 static void MatchFinder_SetDefaultSettings(CMatchFinder *p)
111 {
112 p->cutValue = 32;
113 p->btMode = 1;
114 p->numHashBytes = 4;
115 /* p->skipModeBits = 0; */
116 p->directInput = 0;
117 p->bigHash = 0;
118 }
119
120 #define kCrcPoly 0xEDB88320
121
122 void MatchFinder_Construct(CMatchFinder *p)
123 {
124 UInt32 i;
125 p->bufferBase = 0;
126 p->directInput = 0;
127 p->hash = 0;
128 MatchFinder_SetDefaultSettings(p);
129
130 for (i = 0; i < 256; i++)
131 {
132 UInt32 r = i;
133 int j;
134 for (j = 0; j < 8; j++)
135 r = (r >> 1) ^ (kCrcPoly & ~((r & 1) - 1));
136 p->crc[i] = r;
137 }
138 }
139
140 static void MatchFinder_FreeThisClassMemory(CMatchFinder *p, ISzAlloc *alloc)
141 {
142 alloc->Free(alloc, p->hash);
143 p->hash = 0;
144 }
145
146 void MatchFinder_Free(CMatchFinder *p, ISzAlloc *alloc)
147 {
148 MatchFinder_FreeThisClassMemory(p, alloc);
149 LzInWindow_Free(p, alloc);
150 }
151
152 static CLzRef* AllocRefs(UInt32 num, ISzAlloc *alloc)
153 {
154 size_t sizeInBytes = (size_t)num * sizeof(CLzRef);
155 if (sizeInBytes / sizeof(CLzRef) != num)
156 return 0;
157 return (CLzRef *)alloc->Alloc(alloc, sizeInBytes);
158 }
159
160 int MatchFinder_Create(CMatchFinder *p, UInt32 historySize,
161 UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter,
162 ISzAlloc *alloc)
163 {
164 UInt32 sizeReserv;
165 if (historySize > kMaxHistorySize)
166 {
167 MatchFinder_Free(p, alloc);
168 return 0;
169 }
170 sizeReserv = historySize >> 1;
171 if (historySize > ((UInt32)2 << 30))
172 sizeReserv = historySize >> 2;
173 sizeReserv += (keepAddBufferBefore + matchMaxLen + keepAddBufferAfter) / 2 + (1 << 19);
174
175 p->keepSizeBefore = historySize + keepAddBufferBefore + 1;
176 p->keepSizeAfter = matchMaxLen + keepAddBufferAfter;
177 /* we need one additional byte, since we use MoveBlock after pos++ and before dictionary using */
178 if (LzInWindow_Create(p, sizeReserv, alloc))
179 {
180 UInt32 newCyclicBufferSize = (historySize /* >> p->skipModeBits */) + 1;
181 UInt32 hs;
182 p->matchMaxLen = matchMaxLen;
183 {
184 p->fixedHashSize = 0;
185 if (p->numHashBytes == 2)
186 hs = (1 << 16) - 1;
187 else
188 {
189 hs = historySize - 1;
190 hs |= (hs >> 1);
191 hs |= (hs >> 2);
192 hs |= (hs >> 4);
193 hs |= (hs >> 8);
194 hs >>= 1;
195 /* hs >>= p->skipModeBits; */
196 hs |= 0xFFFF; /* don't change it! It's required for Deflate */
197 if (hs > (1 << 24))
198 {
199 if (p->numHashBytes == 3)
200 hs = (1 << 24) - 1;
201 else
202 hs >>= 1;
203 }
204 }
205 p->hashMask = hs;
206 hs++;
207 if (p->numHashBytes > 2) p->fixedHashSize += kHash2Size;
208 if (p->numHashBytes > 3) p->fixedHashSize += kHash3Size;
209 if (p->numHashBytes > 4) p->fixedHashSize += kHash4Size;
210 hs += p->fixedHashSize;
211 }
212
213 {
214 UInt32 prevSize = p->hashSizeSum + p->numSons;
215 UInt32 newSize;
216 p->historySize = historySize;
217 p->hashSizeSum = hs;
218 p->cyclicBufferSize = newCyclicBufferSize;
219 p->numSons = (p->btMode ? newCyclicBufferSize * 2 : newCyclicBufferSize);
220 newSize = p->hashSizeSum + p->numSons;
221 if (p->hash != 0 && prevSize == newSize)
222 return 1;
223 MatchFinder_FreeThisClassMemory(p, alloc);
224 p->hash = AllocRefs(newSize, alloc);
225 if (p->hash != 0)
226 {
227 p->son = p->hash + p->hashSizeSum;
228 return 1;
229 }
230 }
231 }
232 MatchFinder_Free(p, alloc);
233 return 0;
234 }
235
236 static void MatchFinder_SetLimits(CMatchFinder *p)
237 {
238 UInt32 limit = kMaxValForNormalize - p->pos;
239 UInt32 limit2 = p->cyclicBufferSize - p->cyclicBufferPos;
240 if (limit2 < limit)
241 limit = limit2;
242 limit2 = p->streamPos - p->pos;
243 if (limit2 <= p->keepSizeAfter)
244 {
245 if (limit2 > 0)
246 limit2 = 1;
247 }
248 else
249 limit2 -= p->keepSizeAfter;
250 if (limit2 < limit)
251 limit = limit2;
252 {
253 UInt32 lenLimit = p->streamPos - p->pos;
254 if (lenLimit > p->matchMaxLen)
255 lenLimit = p->matchMaxLen;
256 p->lenLimit = lenLimit;
257 }
258 p->posLimit = p->pos + limit;
259 }
260
261 void MatchFinder_Init(CMatchFinder *p)
262 {
263 UInt32 i;
264 for (i = 0; i < p->hashSizeSum; i++)
265 p->hash[i] = kEmptyHashValue;
266 p->cyclicBufferPos = 0;
267 p->buffer = p->bufferBase;
268 p->pos = p->streamPos = p->cyclicBufferSize;
269 p->result = SZ_OK;
270 p->streamEndWasReached = 0;
271 MatchFinder_ReadBlock(p);
272 MatchFinder_SetLimits(p);
273 }
274
275 static UInt32 MatchFinder_GetSubValue(CMatchFinder *p)
276 {
277 return (p->pos - p->historySize - 1) & kNormalizeMask;
278 }
279
280 void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, UInt32 numItems)
281 {
282 UInt32 i;
283 for (i = 0; i < numItems; i++)
284 {
285 UInt32 value = items[i];
286 if (value <= subValue)
287 value = kEmptyHashValue;
288 else
289 value -= subValue;
290 items[i] = value;
291 }
292 }
293
294 static void MatchFinder_Normalize(CMatchFinder *p)
295 {
296 UInt32 subValue = MatchFinder_GetSubValue(p);
297 MatchFinder_Normalize3(subValue, p->hash, p->hashSizeSum + p->numSons);
298 MatchFinder_ReduceOffsets(p, subValue);
299 }
300
301 static void MatchFinder_CheckLimits(CMatchFinder *p)
302 {
303 if (p->pos == kMaxValForNormalize)
304 MatchFinder_Normalize(p);
305 if (!p->streamEndWasReached && p->keepSizeAfter == p->streamPos - p->pos)
306 MatchFinder_CheckAndMoveAndRead(p);
307 if (p->cyclicBufferPos == p->cyclicBufferSize)
308 p->cyclicBufferPos = 0;
309 MatchFinder_SetLimits(p);
310 }
311
312 static UInt32 * Hc_GetMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
313 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue,
314 UInt32 *distances, UInt32 maxLen)
315 {
316 son[_cyclicBufferPos] = curMatch;
317 for (;;)
318 {
319 UInt32 delta = pos - curMatch;
320 if (cutValue-- == 0 || delta >= _cyclicBufferSize)
321 return distances;
322 {
323 const Byte *pb = cur - delta;
324 curMatch = son[_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)];
325 if (pb[maxLen] == cur[maxLen] && *pb == *cur)
326 {
327 UInt32 len = 0;
328 while (++len != lenLimit)
329 if (pb[len] != cur[len])
330 break;
331 if (maxLen < len)
332 {
333 *distances++ = maxLen = len;
334 *distances++ = delta - 1;
335 if (len == lenLimit)
336 return distances;
337 }
338 }
339 }
340 }
341 }
342
343 UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
344 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue,
345 UInt32 *distances, UInt32 maxLen)
346 {
347 CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;
348 CLzRef *ptr1 = son + (_cyclicBufferPos << 1);
349 UInt32 len0 = 0, len1 = 0;
350 for (;;)
351 {
352 UInt32 delta = pos - curMatch;
353 if (cutValue-- == 0 || delta >= _cyclicBufferSize)
354 {
355 *ptr0 = *ptr1 = kEmptyHashValue;
356 return distances;
357 }
358 {
359 CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);
360 const Byte *pb = cur - delta;
361 UInt32 len = (len0 < len1 ? len0 : len1);
362 if (pb[len] == cur[len])
363 {
364 if (++len != lenLimit && pb[len] == cur[len])
365 while (++len != lenLimit)
366 if (pb[len] != cur[len])
367 break;
368 if (maxLen < len)
369 {
370 *distances++ = maxLen = len;
371 *distances++ = delta - 1;
372 if (len == lenLimit)
373 {
374 *ptr1 = pair[0];
375 *ptr0 = pair[1];
376 return distances;
377 }
378 }
379 }
380 if (pb[len] < cur[len])
381 {
382 *ptr1 = curMatch;
383 ptr1 = pair + 1;
384 curMatch = *ptr1;
385 len1 = len;
386 }
387 else
388 {
389 *ptr0 = curMatch;
390 ptr0 = pair;
391 curMatch = *ptr0;
392 len0 = len;
393 }
394 }
395 }
396 }
397
398 static void SkipMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
399 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue)
400 {
401 CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;
402 CLzRef *ptr1 = son + (_cyclicBufferPos << 1);
403 UInt32 len0 = 0, len1 = 0;
404 for (;;)
405 {
406 UInt32 delta = pos - curMatch;
407 if (cutValue-- == 0 || delta >= _cyclicBufferSize)
408 {
409 *ptr0 = *ptr1 = kEmptyHashValue;
410 return;
411 }
412 {
413 CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);
414 const Byte *pb = cur - delta;
415 UInt32 len = (len0 < len1 ? len0 : len1);
416 if (pb[len] == cur[len])
417 {
418 while (++len != lenLimit)
419 if (pb[len] != cur[len])
420 break;
421 {
422 if (len == lenLimit)
423 {
424 *ptr1 = pair[0];
425 *ptr0 = pair[1];
426 return;
427 }
428 }
429 }
430 if (pb[len] < cur[len])
431 {
432 *ptr1 = curMatch;
433 ptr1 = pair + 1;
434 curMatch = *ptr1;
435 len1 = len;
436 }
437 else
438 {
439 *ptr0 = curMatch;
440 ptr0 = pair;
441 curMatch = *ptr0;
442 len0 = len;
443 }
444 }
445 }
446 }
447
448 #define MOVE_POS \
449 ++p->cyclicBufferPos; \
450 p->buffer++; \
451 if (++p->pos == p->posLimit) MatchFinder_CheckLimits(p);
452
453 #define MOVE_POS_RET MOVE_POS return offset;
454
455 static void MatchFinder_MovePos(CMatchFinder *p) { MOVE_POS; }
456
457 #define GET_MATCHES_HEADER2(minLen, ret_op) \
458 UInt32 lenLimit; UInt32 hashValue; const Byte *cur; UInt32 curMatch; \
459 lenLimit = p->lenLimit; { if (lenLimit < minLen) { MatchFinder_MovePos(p); ret_op; }} \
460 cur = p->buffer;
461
462 #define GET_MATCHES_HEADER(minLen) GET_MATCHES_HEADER2(minLen, return 0)
463 #define SKIP_HEADER(minLen) GET_MATCHES_HEADER2(minLen, continue)
464
465 #define MF_PARAMS(p) p->pos, p->buffer, p->son, p->cyclicBufferPos, p->cyclicBufferSize, p->cutValue
466
467 #define GET_MATCHES_FOOTER(offset, maxLen) \
468 offset = (UInt32)(GetMatchesSpec1(lenLimit, curMatch, MF_PARAMS(p), \
469 distances + offset, maxLen) - distances); MOVE_POS_RET;
470
471 #define SKIP_FOOTER \
472 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); MOVE_POS;
473
474 static UInt32 Bt2_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
475 {
476 UInt32 offset;
477 GET_MATCHES_HEADER(2)
478 HASH2_CALC;
479 curMatch = p->hash[hashValue];
480 p->hash[hashValue] = p->pos;
481 offset = 0;
482 GET_MATCHES_FOOTER(offset, 1)
483 }
484
485 UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
486 {
487 UInt32 offset;
488 GET_MATCHES_HEADER(3)
489 HASH_ZIP_CALC;
490 curMatch = p->hash[hashValue];
491 p->hash[hashValue] = p->pos;
492 offset = 0;
493 GET_MATCHES_FOOTER(offset, 2)
494 }
495
496 static UInt32 Bt3_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
497 {
498 UInt32 hash2Value, delta2, maxLen, offset;
499 GET_MATCHES_HEADER(3)
500
501 HASH3_CALC;
502
503 delta2 = p->pos - p->hash[hash2Value];
504 curMatch = p->hash[kFix3HashSize + hashValue];
505
506 p->hash[hash2Value] =
507 p->hash[kFix3HashSize + hashValue] = p->pos;
508
509
510 maxLen = 2;
511 offset = 0;
512 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
513 {
514 for (; maxLen != lenLimit; maxLen++)
515 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
516 break;
517 distances[0] = maxLen;
518 distances[1] = delta2 - 1;
519 offset = 2;
520 if (maxLen == lenLimit)
521 {
522 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p));
523 MOVE_POS_RET;
524 }
525 }
526 GET_MATCHES_FOOTER(offset, maxLen)
527 }
528
529 static UInt32 Bt4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
530 {
531 UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset;
532 GET_MATCHES_HEADER(4)
533
534 HASH4_CALC;
535
536 delta2 = p->pos - p->hash[ hash2Value];
537 delta3 = p->pos - p->hash[kFix3HashSize + hash3Value];
538 curMatch = p->hash[kFix4HashSize + hashValue];
539
540 p->hash[ hash2Value] =
541 p->hash[kFix3HashSize + hash3Value] =
542 p->hash[kFix4HashSize + hashValue] = p->pos;
543
544 maxLen = 1;
545 offset = 0;
546 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
547 {
548 distances[0] = maxLen = 2;
549 distances[1] = delta2 - 1;
550 offset = 2;
551 }
552 if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur)
553 {
554 maxLen = 3;
555 distances[offset + 1] = delta3 - 1;
556 offset += 2;
557 delta2 = delta3;
558 }
559 if (offset != 0)
560 {
561 for (; maxLen != lenLimit; maxLen++)
562 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
563 break;
564 distances[offset - 2] = maxLen;
565 if (maxLen == lenLimit)
566 {
567 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p));
568 MOVE_POS_RET;
569 }
570 }
571 if (maxLen < 3)
572 maxLen = 3;
573 GET_MATCHES_FOOTER(offset, maxLen)
574 }
575
576 static UInt32 Hc4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
577 {
578 UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset;
579 GET_MATCHES_HEADER(4)
580
581 HASH4_CALC;
582
583 delta2 = p->pos - p->hash[ hash2Value];
584 delta3 = p->pos - p->hash[kFix3HashSize + hash3Value];
585 curMatch = p->hash[kFix4HashSize + hashValue];
586
587 p->hash[ hash2Value] =
588 p->hash[kFix3HashSize + hash3Value] =
589 p->hash[kFix4HashSize + hashValue] = p->pos;
590
591 maxLen = 1;
592 offset = 0;
593 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
594 {
595 distances[0] = maxLen = 2;
596 distances[1] = delta2 - 1;
597 offset = 2;
598 }
599 if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur)
600 {
601 maxLen = 3;
602 distances[offset + 1] = delta3 - 1;
603 offset += 2;
604 delta2 = delta3;
605 }
606 if (offset != 0)
607 {
608 for (; maxLen != lenLimit; maxLen++)
609 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
610 break;
611 distances[offset - 2] = maxLen;
612 if (maxLen == lenLimit)
613 {
614 p->son[p->cyclicBufferPos] = curMatch;
615 MOVE_POS_RET;
616 }
617 }
618 if (maxLen < 3)
619 maxLen = 3;
620 offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p),
621 distances + offset, maxLen) - (distances));
622 MOVE_POS_RET
623 }
624
625 UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
626 {
627 UInt32 offset;
628 GET_MATCHES_HEADER(3)
629 HASH_ZIP_CALC;
630 curMatch = p->hash[hashValue];
631 p->hash[hashValue] = p->pos;
632 offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p),
633 distances, 2) - (distances));
634 MOVE_POS_RET
635 }
636
637 static void Bt2_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
638 {
639 do
640 {
641 SKIP_HEADER(2)
642 HASH2_CALC;
643 curMatch = p->hash[hashValue];
644 p->hash[hashValue] = p->pos;
645 SKIP_FOOTER
646 }
647 while (--num != 0);
648 }
649
650 void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
651 {
652 do
653 {
654 SKIP_HEADER(3)
655 HASH_ZIP_CALC;
656 curMatch = p->hash[hashValue];
657 p->hash[hashValue] = p->pos;
658 SKIP_FOOTER
659 }
660 while (--num != 0);
661 }
662
663 static void Bt3_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
664 {
665 do
666 {
667 UInt32 hash2Value;
668 SKIP_HEADER(3)
669 HASH3_CALC;
670 curMatch = p->hash[kFix3HashSize + hashValue];
671 p->hash[hash2Value] =
672 p->hash[kFix3HashSize + hashValue] = p->pos;
673 SKIP_FOOTER
674 }
675 while (--num != 0);
676 }
677
678 static void Bt4_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
679 {
680 do
681 {
682 UInt32 hash2Value, hash3Value;
683 SKIP_HEADER(4)
684 HASH4_CALC;
685 curMatch = p->hash[kFix4HashSize + hashValue];
686 p->hash[ hash2Value] =
687 p->hash[kFix3HashSize + hash3Value] = p->pos;
688 p->hash[kFix4HashSize + hashValue] = p->pos;
689 SKIP_FOOTER
690 }
691 while (--num != 0);
692 }
693
694 static void Hc4_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
695 {
696 do
697 {
698 UInt32 hash2Value, hash3Value;
699 SKIP_HEADER(4)
700 HASH4_CALC;
701 curMatch = p->hash[kFix4HashSize + hashValue];
702 p->hash[ hash2Value] =
703 p->hash[kFix3HashSize + hash3Value] =
704 p->hash[kFix4HashSize + hashValue] = p->pos;
705 p->son[p->cyclicBufferPos] = curMatch;
706 MOVE_POS
707 }
708 while (--num != 0);
709 }
710
711 void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
712 {
713 do
714 {
715 SKIP_HEADER(3)
716 HASH_ZIP_CALC;
717 curMatch = p->hash[hashValue];
718 p->hash[hashValue] = p->pos;
719 p->son[p->cyclicBufferPos] = curMatch;
720 MOVE_POS
721 }
722 while (--num != 0);
723 }
724
725 void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder *vTable)
726 {
727 vTable->Init = (Mf_Init_Func)MatchFinder_Init;
728 vTable->GetIndexByte = (Mf_GetIndexByte_Func)MatchFinder_GetIndexByte;
729 vTable->GetNumAvailableBytes = (Mf_GetNumAvailableBytes_Func)MatchFinder_GetNumAvailableBytes;
730 vTable->GetPointerToCurrentPos = (Mf_GetPointerToCurrentPos_Func)MatchFinder_GetPointerToCurrentPos;
731 if (!p->btMode)
732 {
733 vTable->GetMatches = (Mf_GetMatches_Func)Hc4_MatchFinder_GetMatches;
734 vTable->Skip = (Mf_Skip_Func)Hc4_MatchFinder_Skip;
735 }
736 else if (p->numHashBytes == 2)
737 {
738 vTable->GetMatches = (Mf_GetMatches_Func)Bt2_MatchFinder_GetMatches;
739 vTable->Skip = (Mf_Skip_Func)Bt2_MatchFinder_Skip;
740 }
741 else if (p->numHashBytes == 3)
742 {
743 vTable->GetMatches = (Mf_GetMatches_Func)Bt3_MatchFinder_GetMatches;
744 vTable->Skip = (Mf_Skip_Func)Bt3_MatchFinder_Skip;
745 }
746 else
747 {
748 vTable->GetMatches = (Mf_GetMatches_Func)Bt4_MatchFinder_GetMatches;
749 vTable->Skip = (Mf_Skip_Func)Bt4_MatchFinder_Skip;
750 }
751 }