1 /*
2 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
3 * Use is subject to license terms.
4 */
5
6 /* LzFind.c -- Match finder for LZ algorithms
7 2008-10-04 : Igor Pavlov : Public domain */
8
9 #include <string.h>
10
11 #include "LzFind.h"
12 #include "LzHash.h"
13
14 #define kEmptyHashValue 0
15 #define kMaxValForNormalize ((UInt32)0xFFFFFFFF)
16 #define kNormalizeStepMin (1 << 10) /* it must be power of 2 */
17 #define kNormalizeMask (~(kNormalizeStepMin - 1))
18 #define kMaxHistorySize ((UInt32)3 << 30)
19
20 #define kStartMaxLen 3
21
LzInWindow_Free(CMatchFinder * p,ISzAlloc * alloc)22 static void LzInWindow_Free(CMatchFinder *p, ISzAlloc *alloc)
23 {
24 if (!p->directInput)
25 {
26 alloc->Free(alloc, p->bufferBase, 0);
27 p->bufferBase = 0;
28 }
29 }
30
31 /* keepSizeBefore + keepSizeAfter + keepSizeReserv must be < 4G) */
32
LzInWindow_Create(CMatchFinder * p,UInt32 keepSizeReserv,ISzAlloc * alloc)33 static int LzInWindow_Create(CMatchFinder *p, UInt32 keepSizeReserv, ISzAlloc *alloc)
34 {
35 UInt32 blockSize = p->keepSizeBefore + p->keepSizeAfter + keepSizeReserv;
36 if (p->directInput)
37 {
38 p->blockSize = blockSize;
39 return 1;
40 }
41 if (p->bufferBase == 0 || p->blockSize != blockSize)
42 {
43 LzInWindow_Free(p, alloc);
44 p->blockSize = blockSize;
45 p->bufferBase = (Byte *)alloc->Alloc(alloc, (size_t)blockSize);
46 }
47 return (p->bufferBase != 0);
48 }
49
MatchFinder_GetPointerToCurrentPos(CMatchFinder * p)50 Byte *MatchFinder_GetPointerToCurrentPos(CMatchFinder *p) { return p->buffer; }
MatchFinder_GetIndexByte(CMatchFinder * p,Int32 index)51 Byte MatchFinder_GetIndexByte(CMatchFinder *p, Int32 index) { return p->buffer[index]; }
52
MatchFinder_GetNumAvailableBytes(CMatchFinder * p)53 UInt32 MatchFinder_GetNumAvailableBytes(CMatchFinder *p) { return p->streamPos - p->pos; }
54
MatchFinder_ReduceOffsets(CMatchFinder * p,UInt32 subValue)55 void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue)
56 {
57 p->posLimit -= subValue;
58 p->pos -= subValue;
59 p->streamPos -= subValue;
60 }
61
MatchFinder_ReadBlock(CMatchFinder * p)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 = (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
MatchFinder_MoveBlock(CMatchFinder * p)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
MatchFinder_NeedMove(CMatchFinder * p)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
MatchFinder_ReadIfRequired(CMatchFinder * p)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
MatchFinder_CheckAndMoveAndRead(CMatchFinder * p)108 static void MatchFinder_CheckAndMoveAndRead(CMatchFinder *p)
109 {
110 if (MatchFinder_NeedMove(p))
111 MatchFinder_MoveBlock(p);
112 MatchFinder_ReadBlock(p);
113 }
114
MatchFinder_SetDefaultSettings(CMatchFinder * p)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
MatchFinder_Construct(CMatchFinder * p)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
MatchFinder_FreeThisClassMemory(CMatchFinder * p,ISzAlloc * alloc)145 static void MatchFinder_FreeThisClassMemory(CMatchFinder *p, ISzAlloc *alloc)
146 {
147 alloc->Free(alloc, p->hash, 0);
148 p->hash = 0;
149 }
150
MatchFinder_Free(CMatchFinder * p,ISzAlloc * alloc)151 void MatchFinder_Free(CMatchFinder *p, ISzAlloc *alloc)
152 {
153 MatchFinder_FreeThisClassMemory(p, alloc);
154 LzInWindow_Free(p, alloc);
155 }
156
AllocRefs(UInt32 num,ISzAlloc * alloc)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
MatchFinder_Create(CMatchFinder * p,UInt32 historySize,UInt32 keepAddBufferBefore,UInt32 matchMaxLen,UInt32 keepAddBufferAfter,ISzAlloc * alloc)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
MatchFinder_SetLimits(CMatchFinder * p)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
MatchFinder_Init(CMatchFinder * p)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
MatchFinder_GetSubValue(CMatchFinder * p)280 static UInt32 MatchFinder_GetSubValue(CMatchFinder *p)
281 {
282 return (p->pos - p->historySize - 1) & kNormalizeMask;
283 }
284
MatchFinder_Normalize3(UInt32 subValue,CLzRef * items,UInt32 numItems)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
MatchFinder_Normalize(CMatchFinder * p)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
MatchFinder_CheckLimits(CMatchFinder * p)306 static void MatchFinder_CheckLimits(CMatchFinder *p)
307 {
308 if (p->pos == kMaxValForNormalize)
309 MatchFinder_Normalize(p);
310 if (!p->streamEndWasReached && p->keepSizeAfter == p->streamPos - p->pos)
311 MatchFinder_CheckAndMoveAndRead(p);
312 if (p->cyclicBufferPos == p->cyclicBufferSize)
313 p->cyclicBufferPos = 0;
314 MatchFinder_SetLimits(p);
315 }
316
Hc_GetMatchesSpec(UInt32 lenLimit,UInt32 curMatch,UInt32 pos,const Byte * cur,CLzRef * son,UInt32 _cyclicBufferPos,UInt32 _cyclicBufferSize,UInt32 cutValue,UInt32 * distances,UInt32 maxLen)317 static UInt32 * Hc_GetMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
318 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue,
319 UInt32 *distances, UInt32 maxLen)
320 {
321 son[_cyclicBufferPos] = curMatch;
322 for (;;)
323 {
324 UInt32 delta = pos - curMatch;
325 if (cutValue-- == 0 || delta >= _cyclicBufferSize)
326 return distances;
327 {
328 const Byte *pb = cur - delta;
329 curMatch = son[_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)];
330 if (pb[maxLen] == cur[maxLen] && *pb == *cur)
331 {
332 UInt32 len = 0;
333 while (++len != lenLimit)
334 if (pb[len] != cur[len])
335 break;
336 if (maxLen < len)
337 {
338 *distances++ = maxLen = len;
339 *distances++ = delta - 1;
340 if (len == lenLimit)
341 return distances;
342 }
343 }
344 }
345 }
346 }
347
GetMatchesSpec1(UInt32 lenLimit,UInt32 curMatch,UInt32 pos,const Byte * cur,CLzRef * son,UInt32 _cyclicBufferPos,UInt32 _cyclicBufferSize,UInt32 cutValue,UInt32 * distances,UInt32 maxLen)348 UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
349 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue,
350 UInt32 *distances, UInt32 maxLen)
351 {
352 CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;
353 CLzRef *ptr1 = son + (_cyclicBufferPos << 1);
354 UInt32 len0 = 0, len1 = 0;
355 for (;;)
356 {
357 UInt32 delta = pos - curMatch;
358 if (cutValue-- == 0 || delta >= _cyclicBufferSize)
359 {
360 *ptr0 = *ptr1 = kEmptyHashValue;
361 return distances;
362 }
363 {
364 CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);
365 const Byte *pb = cur - delta;
366 UInt32 len = (len0 < len1 ? len0 : len1);
367 if (pb[len] == cur[len])
368 {
369 if (++len != lenLimit && pb[len] == cur[len])
370 while (++len != lenLimit)
371 if (pb[len] != cur[len])
372 break;
373 if (maxLen < len)
374 {
375 *distances++ = maxLen = len;
376 *distances++ = delta - 1;
377 if (len == lenLimit)
378 {
379 *ptr1 = pair[0];
380 *ptr0 = pair[1];
381 return distances;
382 }
383 }
384 }
385 if (pb[len] < cur[len])
386 {
387 *ptr1 = curMatch;
388 ptr1 = pair + 1;
389 curMatch = *ptr1;
390 len1 = len;
391 }
392 else
393 {
394 *ptr0 = curMatch;
395 ptr0 = pair;
396 curMatch = *ptr0;
397 len0 = len;
398 }
399 }
400 }
401 }
402
SkipMatchesSpec(UInt32 lenLimit,UInt32 curMatch,UInt32 pos,const Byte * cur,CLzRef * son,UInt32 _cyclicBufferPos,UInt32 _cyclicBufferSize,UInt32 cutValue)403 static void SkipMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
404 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue)
405 {
406 CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;
407 CLzRef *ptr1 = son + (_cyclicBufferPos << 1);
408 UInt32 len0 = 0, len1 = 0;
409 for (;;)
410 {
411 UInt32 delta = pos - curMatch;
412 if (cutValue-- == 0 || delta >= _cyclicBufferSize)
413 {
414 *ptr0 = *ptr1 = kEmptyHashValue;
415 return;
416 }
417 {
418 CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);
419 const Byte *pb = cur - delta;
420 UInt32 len = (len0 < len1 ? len0 : len1);
421 if (pb[len] == cur[len])
422 {
423 while (++len != lenLimit)
424 if (pb[len] != cur[len])
425 break;
426 {
427 if (len == lenLimit)
428 {
429 *ptr1 = pair[0];
430 *ptr0 = pair[1];
431 return;
432 }
433 }
434 }
435 if (pb[len] < cur[len])
436 {
437 *ptr1 = curMatch;
438 ptr1 = pair + 1;
439 curMatch = *ptr1;
440 len1 = len;
441 }
442 else
443 {
444 *ptr0 = curMatch;
445 ptr0 = pair;
446 curMatch = *ptr0;
447 len0 = len;
448 }
449 }
450 }
451 }
452
453 #define MOVE_POS \
454 ++p->cyclicBufferPos; \
455 p->buffer++; \
456 if (++p->pos == p->posLimit) MatchFinder_CheckLimits(p);
457
458 #define MOVE_POS_RET MOVE_POS return offset;
459
MatchFinder_MovePos(CMatchFinder * p)460 static void MatchFinder_MovePos(CMatchFinder *p) { MOVE_POS; }
461
462 #define GET_MATCHES_HEADER2(minLen, ret_op) \
463 UInt32 lenLimit; UInt32 hashValue; const Byte *cur; UInt32 curMatch; \
464 lenLimit = p->lenLimit; { if (lenLimit < minLen) { MatchFinder_MovePos(p); ret_op; }} \
465 cur = p->buffer;
466
467 #define GET_MATCHES_HEADER(minLen) GET_MATCHES_HEADER2(minLen, return 0)
468 #define SKIP_HEADER(minLen) GET_MATCHES_HEADER2(minLen, continue)
469
470 #define MF_PARAMS(p) p->pos, p->buffer, p->son, p->cyclicBufferPos, p->cyclicBufferSize, p->cutValue
471
472 #define GET_MATCHES_FOOTER(offset, maxLen) \
473 offset = (UInt32)(GetMatchesSpec1(lenLimit, curMatch, MF_PARAMS(p), \
474 distances + offset, maxLen) - distances); MOVE_POS_RET;
475
476 #define SKIP_FOOTER \
477 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); MOVE_POS;
478
Bt2_MatchFinder_GetMatches(CMatchFinder * p,UInt32 * distances)479 static UInt32 Bt2_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
480 {
481 UInt32 offset;
482 GET_MATCHES_HEADER(2)
483 HASH2_CALC;
484 curMatch = p->hash[hashValue];
485 p->hash[hashValue] = p->pos;
486 offset = 0;
487 GET_MATCHES_FOOTER(offset, 1)
488 }
489
Bt3Zip_MatchFinder_GetMatches(CMatchFinder * p,UInt32 * distances)490 UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
491 {
492 UInt32 offset;
493 GET_MATCHES_HEADER(3)
494 HASH_ZIP_CALC;
495 curMatch = p->hash[hashValue];
496 p->hash[hashValue] = p->pos;
497 offset = 0;
498 GET_MATCHES_FOOTER(offset, 2)
499 }
500
Bt3_MatchFinder_GetMatches(CMatchFinder * p,UInt32 * distances)501 static UInt32 Bt3_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
502 {
503 UInt32 hash2Value, delta2, maxLen, offset;
504 GET_MATCHES_HEADER(3)
505
506 HASH3_CALC;
507
508 delta2 = p->pos - p->hash[hash2Value];
509 curMatch = p->hash[kFix3HashSize + hashValue];
510
511 p->hash[hash2Value] =
512 p->hash[kFix3HashSize + hashValue] = p->pos;
513
514
515 maxLen = 2;
516 offset = 0;
517 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
518 {
519 for (; maxLen != lenLimit; maxLen++)
520 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
521 break;
522 distances[0] = maxLen;
523 distances[1] = delta2 - 1;
524 offset = 2;
525 if (maxLen == lenLimit)
526 {
527 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p));
528 MOVE_POS_RET;
529 }
530 }
531 GET_MATCHES_FOOTER(offset, maxLen)
532 }
533
Bt4_MatchFinder_GetMatches(CMatchFinder * p,UInt32 * distances)534 static UInt32 Bt4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
535 {
536 UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset;
537 GET_MATCHES_HEADER(4)
538
539 HASH4_CALC;
540
541 delta2 = p->pos - p->hash[ hash2Value];
542 delta3 = p->pos - p->hash[kFix3HashSize + hash3Value];
543 curMatch = p->hash[kFix4HashSize + hashValue];
544
545 p->hash[ hash2Value] =
546 p->hash[kFix3HashSize + hash3Value] =
547 p->hash[kFix4HashSize + hashValue] = p->pos;
548
549 maxLen = 1;
550 offset = 0;
551 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
552 {
553 distances[0] = maxLen = 2;
554 distances[1] = delta2 - 1;
555 offset = 2;
556 }
557 if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur)
558 {
559 maxLen = 3;
560 distances[offset + 1] = delta3 - 1;
561 offset += 2;
562 delta2 = delta3;
563 }
564 if (offset != 0)
565 {
566 for (; maxLen != lenLimit; maxLen++)
567 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
568 break;
569 distances[offset - 2] = maxLen;
570 if (maxLen == lenLimit)
571 {
572 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p));
573 MOVE_POS_RET;
574 }
575 }
576 if (maxLen < 3)
577 maxLen = 3;
578 GET_MATCHES_FOOTER(offset, maxLen)
579 }
580
Hc4_MatchFinder_GetMatches(CMatchFinder * p,UInt32 * distances)581 static UInt32 Hc4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
582 {
583 UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset;
584 GET_MATCHES_HEADER(4)
585
586 HASH4_CALC;
587
588 delta2 = p->pos - p->hash[ hash2Value];
589 delta3 = p->pos - p->hash[kFix3HashSize + hash3Value];
590 curMatch = p->hash[kFix4HashSize + hashValue];
591
592 p->hash[ hash2Value] =
593 p->hash[kFix3HashSize + hash3Value] =
594 p->hash[kFix4HashSize + hashValue] = p->pos;
595
596 maxLen = 1;
597 offset = 0;
598 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
599 {
600 distances[0] = maxLen = 2;
601 distances[1] = delta2 - 1;
602 offset = 2;
603 }
604 if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur)
605 {
606 maxLen = 3;
607 distances[offset + 1] = delta3 - 1;
608 offset += 2;
609 delta2 = delta3;
610 }
611 if (offset != 0)
612 {
613 for (; maxLen != lenLimit; maxLen++)
614 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
615 break;
616 distances[offset - 2] = maxLen;
617 if (maxLen == lenLimit)
618 {
619 p->son[p->cyclicBufferPos] = curMatch;
620 MOVE_POS_RET;
621 }
622 }
623 if (maxLen < 3)
624 maxLen = 3;
625 offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p),
626 distances + offset, maxLen) - (distances));
627 MOVE_POS_RET
628 }
629
Hc3Zip_MatchFinder_GetMatches(CMatchFinder * p,UInt32 * distances)630 UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
631 {
632 UInt32 offset;
633 GET_MATCHES_HEADER(3)
634 HASH_ZIP_CALC;
635 curMatch = p->hash[hashValue];
636 p->hash[hashValue] = p->pos;
637 offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p),
638 distances, 2) - (distances));
639 MOVE_POS_RET
640 }
641
Bt2_MatchFinder_Skip(CMatchFinder * p,UInt32 num)642 static void Bt2_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
643 {
644 do
645 {
646 SKIP_HEADER(2)
647 HASH2_CALC;
648 curMatch = p->hash[hashValue];
649 p->hash[hashValue] = p->pos;
650 SKIP_FOOTER
651 }
652 while (--num != 0);
653 }
654
Bt3Zip_MatchFinder_Skip(CMatchFinder * p,UInt32 num)655 void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
656 {
657 do
658 {
659 SKIP_HEADER(3)
660 HASH_ZIP_CALC;
661 curMatch = p->hash[hashValue];
662 p->hash[hashValue] = p->pos;
663 SKIP_FOOTER
664 }
665 while (--num != 0);
666 }
667
Bt3_MatchFinder_Skip(CMatchFinder * p,UInt32 num)668 static void Bt3_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
669 {
670 do
671 {
672 UInt32 hash2Value;
673 SKIP_HEADER(3)
674 HASH3_CALC;
675 curMatch = p->hash[kFix3HashSize + hashValue];
676 p->hash[hash2Value] =
677 p->hash[kFix3HashSize + hashValue] = p->pos;
678 SKIP_FOOTER
679 }
680 while (--num != 0);
681 }
682
Bt4_MatchFinder_Skip(CMatchFinder * p,UInt32 num)683 static void Bt4_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
684 {
685 do
686 {
687 UInt32 hash2Value, hash3Value;
688 SKIP_HEADER(4)
689 HASH4_CALC;
690 curMatch = p->hash[kFix4HashSize + hashValue];
691 p->hash[ hash2Value] =
692 p->hash[kFix3HashSize + hash3Value] = p->pos;
693 p->hash[kFix4HashSize + hashValue] = p->pos;
694 SKIP_FOOTER
695 }
696 while (--num != 0);
697 }
698
Hc4_MatchFinder_Skip(CMatchFinder * p,UInt32 num)699 static void Hc4_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
700 {
701 do
702 {
703 UInt32 hash2Value, hash3Value;
704 SKIP_HEADER(4)
705 HASH4_CALC;
706 curMatch = p->hash[kFix4HashSize + hashValue];
707 p->hash[ hash2Value] =
708 p->hash[kFix3HashSize + hash3Value] =
709 p->hash[kFix4HashSize + hashValue] = p->pos;
710 p->son[p->cyclicBufferPos] = curMatch;
711 MOVE_POS
712 }
713 while (--num != 0);
714 }
715
Hc3Zip_MatchFinder_Skip(CMatchFinder * p,UInt32 num)716 void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
717 {
718 do
719 {
720 SKIP_HEADER(3)
721 HASH_ZIP_CALC;
722 curMatch = p->hash[hashValue];
723 p->hash[hashValue] = p->pos;
724 p->son[p->cyclicBufferPos] = curMatch;
725 MOVE_POS
726 }
727 while (--num != 0);
728 }
729
MatchFinder_CreateVTable(CMatchFinder * p,IMatchFinder * vTable)730 void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder *vTable)
731 {
732 vTable->Init = (Mf_Init_Func)MatchFinder_Init;
733 vTable->GetIndexByte = (Mf_GetIndexByte_Func)MatchFinder_GetIndexByte;
734 vTable->GetNumAvailableBytes = (Mf_GetNumAvailableBytes_Func)MatchFinder_GetNumAvailableBytes;
735 vTable->GetPointerToCurrentPos = (Mf_GetPointerToCurrentPos_Func)MatchFinder_GetPointerToCurrentPos;
736 if (!p->btMode)
737 {
738 vTable->GetMatches = (Mf_GetMatches_Func)Hc4_MatchFinder_GetMatches;
739 vTable->Skip = (Mf_Skip_Func)Hc4_MatchFinder_Skip;
740 }
741 else if (p->numHashBytes == 2)
742 {
743 vTable->GetMatches = (Mf_GetMatches_Func)Bt2_MatchFinder_GetMatches;
744 vTable->Skip = (Mf_Skip_Func)Bt2_MatchFinder_Skip;
745 }
746 else if (p->numHashBytes == 3)
747 {
748 vTable->GetMatches = (Mf_GetMatches_Func)Bt3_MatchFinder_GetMatches;
749 vTable->Skip = (Mf_Skip_Func)Bt3_MatchFinder_Skip;
750 }
751 else
752 {
753 vTable->GetMatches = (Mf_GetMatches_Func)Bt4_MatchFinder_GetMatches;
754 vTable->Skip = (Mf_Skip_Func)Bt4_MatchFinder_Skip;
755 }
756 }
757