ReactOS  0.4.15-dev-5500-g82cf6c2
zstd_lazy.c
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
3  * All rights reserved.
4  *
5  * This source code is licensed under both the BSD-style license (found in the
6  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7  * in the COPYING file in the root directory of this source tree).
8  * You may select, at your option, one of the above-listed licenses.
9  */
10 
11 #include "zstd_compress_internal.h"
12 #include "zstd_lazy.h"
13 
14 
15 /*-*************************************
16 * Binary Tree search
17 ***************************************/
18 
19 static void
21  const BYTE* ip, const BYTE* iend,
22  U32 mls)
23 {
24  const ZSTD_compressionParameters* const cParams = &ms->cParams;
25  U32* const hashTable = ms->hashTable;
26  U32 const hashLog = cParams->hashLog;
27 
28  U32* const bt = ms->chainTable;
29  U32 const btLog = cParams->chainLog - 1;
30  U32 const btMask = (1 << btLog) - 1;
31 
32  const BYTE* const base = ms->window.base;
33  U32 const target = (U32)(ip - base);
34  U32 idx = ms->nextToUpdate;
35 
36  if (idx != target)
37  DEBUGLOG(7, "ZSTD_updateDUBT, from %u to %u (dictLimit:%u)",
38  idx, target, ms->window.dictLimit);
39  assert(ip + 8 <= iend); /* condition for ZSTD_hashPtr */
40  (void)iend;
41 
42  assert(idx >= ms->window.dictLimit); /* condition for valid base+idx */
43  for ( ; idx < target ; idx++) {
44  size_t const h = ZSTD_hashPtr(base + idx, hashLog, mls); /* assumption : ip + 8 <= iend */
45  U32 const matchIndex = hashTable[h];
46 
47  U32* const nextCandidatePtr = bt + 2*(idx&btMask);
48  U32* const sortMarkPtr = nextCandidatePtr + 1;
49 
50  DEBUGLOG(8, "ZSTD_updateDUBT: insert %u", idx);
51  hashTable[h] = idx; /* Update Hash Table */
52  *nextCandidatePtr = matchIndex; /* update BT like a chain */
53  *sortMarkPtr = ZSTD_DUBT_UNSORTED_MARK;
54  }
55  ms->nextToUpdate = target;
56 }
57 
58 
63 static void
65  U32 current, const BYTE* inputEnd,
66  U32 nbCompares, U32 btLow,
67  const ZSTD_dictMode_e dictMode)
68 {
69  const ZSTD_compressionParameters* const cParams = &ms->cParams;
70  U32* const bt = ms->chainTable;
71  U32 const btLog = cParams->chainLog - 1;
72  U32 const btMask = (1 << btLog) - 1;
73  size_t commonLengthSmaller=0, commonLengthLarger=0;
74  const BYTE* const base = ms->window.base;
75  const BYTE* const dictBase = ms->window.dictBase;
76  const U32 dictLimit = ms->window.dictLimit;
77  const BYTE* const ip = (current>=dictLimit) ? base + current : dictBase + current;
78  const BYTE* const iend = (current>=dictLimit) ? inputEnd : dictBase + dictLimit;
79  const BYTE* const dictEnd = dictBase + dictLimit;
80  const BYTE* const prefixStart = base + dictLimit;
81  const BYTE* match;
82  U32* smallerPtr = bt + 2*(current&btMask);
83  U32* largerPtr = smallerPtr + 1;
84  U32 matchIndex = *smallerPtr; /* this candidate is unsorted : next sorted candidate is reached through *smallerPtr, while *largerPtr contains previous unsorted candidate (which is already saved and can be overwritten) */
85  U32 dummy32; /* to be nullified at the end */
86  U32 const windowValid = ms->window.lowLimit;
87  U32 const maxDistance = 1U << cParams->windowLog;
88  U32 const windowLow = (current - windowValid > maxDistance) ? current - maxDistance : windowValid;
89 
90 
91  DEBUGLOG(8, "ZSTD_insertDUBT1(%u) (dictLimit=%u, lowLimit=%u)",
92  current, dictLimit, windowLow);
93  assert(current >= btLow);
94  assert(ip < iend); /* condition for ZSTD_count */
95 
96  while (nbCompares-- && (matchIndex > windowLow)) {
97  U32* const nextPtr = bt + 2*(matchIndex & btMask);
98  size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
99  assert(matchIndex < current);
100  /* note : all candidates are now supposed sorted,
101  * but it's still possible to have nextPtr[1] == ZSTD_DUBT_UNSORTED_MARK
102  * when a real index has the same value as ZSTD_DUBT_UNSORTED_MARK */
103 
104  if ( (dictMode != ZSTD_extDict)
105  || (matchIndex+matchLength >= dictLimit) /* both in current segment*/
106  || (current < dictLimit) /* both in extDict */) {
107  const BYTE* const mBase = ( (dictMode != ZSTD_extDict)
108  || (matchIndex+matchLength >= dictLimit)) ?
109  base : dictBase;
110  assert( (matchIndex+matchLength >= dictLimit) /* might be wrong if extDict is incorrectly set to 0 */
111  || (current < dictLimit) );
112  match = mBase + matchIndex;
113  matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend);
114  } else {
115  match = dictBase + matchIndex;
116  matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart);
117  if (matchIndex+matchLength >= dictLimit)
118  match = base + matchIndex; /* preparation for next read of match[matchLength] */
119  }
120 
121  DEBUGLOG(8, "ZSTD_insertDUBT1: comparing %u with %u : found %u common bytes ",
122  current, matchIndex, (U32)matchLength);
123 
124  if (ip+matchLength == iend) { /* equal : no way to know if inf or sup */
125  break; /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt tree */
126  }
127 
128  if (match[matchLength] < ip[matchLength]) { /* necessarily within buffer */
129  /* match is smaller than current */
130  *smallerPtr = matchIndex; /* update smaller idx */
131  commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
132  if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop searching */
133  DEBUGLOG(8, "ZSTD_insertDUBT1: %u (>btLow=%u) is smaller : next => %u",
134  matchIndex, btLow, nextPtr[1]);
135  smallerPtr = nextPtr+1; /* new "candidate" => larger than match, which was smaller than target */
136  matchIndex = nextPtr[1]; /* new matchIndex, larger than previous and closer to current */
137  } else {
138  /* match is larger than current */
139  *largerPtr = matchIndex;
140  commonLengthLarger = matchLength;
141  if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop searching */
142  DEBUGLOG(8, "ZSTD_insertDUBT1: %u (>btLow=%u) is larger => %u",
143  matchIndex, btLow, nextPtr[0]);
144  largerPtr = nextPtr;
145  matchIndex = nextPtr[0];
146  } }
147 
148  *smallerPtr = *largerPtr = 0;
149 }
150 
151 
152 static size_t
154  ZSTD_matchState_t* ms,
155  const BYTE* const ip, const BYTE* const iend,
156  size_t* offsetPtr,
157  size_t bestLength,
158  U32 nbCompares,
159  U32 const mls,
160  const ZSTD_dictMode_e dictMode)
161 {
162  const ZSTD_matchState_t * const dms = ms->dictMatchState;
163  const ZSTD_compressionParameters* const dmsCParams = &dms->cParams;
164  const U32 * const dictHashTable = dms->hashTable;
165  U32 const hashLog = dmsCParams->hashLog;
166  size_t const h = ZSTD_hashPtr(ip, hashLog, mls);
167  U32 dictMatchIndex = dictHashTable[h];
168 
169  const BYTE* const base = ms->window.base;
170  const BYTE* const prefixStart = base + ms->window.dictLimit;
171  U32 const current = (U32)(ip-base);
172  const BYTE* const dictBase = dms->window.base;
173  const BYTE* const dictEnd = dms->window.nextSrc;
174  U32 const dictHighLimit = (U32)(dms->window.nextSrc - dms->window.base);
175  U32 const dictLowLimit = dms->window.lowLimit;
176  U32 const dictIndexDelta = ms->window.lowLimit - dictHighLimit;
177 
178  U32* const dictBt = dms->chainTable;
179  U32 const btLog = dmsCParams->chainLog - 1;
180  U32 const btMask = (1 << btLog) - 1;
181  U32 const btLow = (btMask >= dictHighLimit - dictLowLimit) ? dictLowLimit : dictHighLimit - btMask;
182 
183  size_t commonLengthSmaller=0, commonLengthLarger=0;
184 
185  (void)dictMode;
186  assert(dictMode == ZSTD_dictMatchState);
187 
188  while (nbCompares-- && (dictMatchIndex > dictLowLimit)) {
189  U32* const nextPtr = dictBt + 2*(dictMatchIndex & btMask);
190  size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
191  const BYTE* match = dictBase + dictMatchIndex;
192  matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart);
193  if (dictMatchIndex+matchLength >= dictHighLimit)
194  match = base + dictMatchIndex + dictIndexDelta; /* to prepare for next usage of match[matchLength] */
195 
196  if (matchLength > bestLength) {
197  U32 matchIndex = dictMatchIndex + dictIndexDelta;
198  if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit32(current-matchIndex+1) - ZSTD_highbit32((U32)offsetPtr[0]+1)) ) {
199  DEBUGLOG(9, "ZSTD_DUBT_findBetterDictMatch(%u) : found better match length %u -> %u and offsetCode %u -> %u (dictMatchIndex %u, matchIndex %u)",
200  current, (U32)bestLength, (U32)matchLength, (U32)*offsetPtr, ZSTD_REP_MOVE + current - matchIndex, dictMatchIndex, matchIndex);
201  bestLength = matchLength, *offsetPtr = ZSTD_REP_MOVE + current - matchIndex;
202  }
203  if (ip+matchLength == iend) { /* reached end of input : ip[matchLength] is not valid, no way to know if it's larger or smaller than match */
204  break; /* drop, to guarantee consistency (miss a little bit of compression) */
205  }
206  }
207 
208  if (match[matchLength] < ip[matchLength]) {
209  if (dictMatchIndex <= btLow) { break; } /* beyond tree size, stop the search */
210  commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
211  dictMatchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */
212  } else {
213  /* match is larger than current */
214  if (dictMatchIndex <= btLow) { break; } /* beyond tree size, stop the search */
215  commonLengthLarger = matchLength;
216  dictMatchIndex = nextPtr[0];
217  }
218  }
219 
220  if (bestLength >= MINMATCH) {
221  U32 const mIndex = current - ((U32)*offsetPtr - ZSTD_REP_MOVE); (void)mIndex;
222  DEBUGLOG(8, "ZSTD_DUBT_findBetterDictMatch(%u) : found match of length %u and offsetCode %u (pos %u)",
223  current, (U32)bestLength, (U32)*offsetPtr, mIndex);
224  }
225  return bestLength;
226 
227 }
228 
229 
230 static size_t
232  const BYTE* const ip, const BYTE* const iend,
233  size_t* offsetPtr,
234  U32 const mls,
235  const ZSTD_dictMode_e dictMode)
236 {
237  const ZSTD_compressionParameters* const cParams = &ms->cParams;
238  U32* const hashTable = ms->hashTable;
239  U32 const hashLog = cParams->hashLog;
240  size_t const h = ZSTD_hashPtr(ip, hashLog, mls);
241  U32 matchIndex = hashTable[h];
242 
243  const BYTE* const base = ms->window.base;
244  U32 const current = (U32)(ip-base);
245  U32 const windowLow = ZSTD_getLowestMatchIndex(ms, current, cParams->windowLog);
246 
247  U32* const bt = ms->chainTable;
248  U32 const btLog = cParams->chainLog - 1;
249  U32 const btMask = (1 << btLog) - 1;
250  U32 const btLow = (btMask >= current) ? 0 : current - btMask;
251  U32 const unsortLimit = MAX(btLow, windowLow);
252 
253  U32* nextCandidate = bt + 2*(matchIndex&btMask);
254  U32* unsortedMark = bt + 2*(matchIndex&btMask) + 1;
255  U32 nbCompares = 1U << cParams->searchLog;
256  U32 nbCandidates = nbCompares;
257  U32 previousCandidate = 0;
258 
259  DEBUGLOG(7, "ZSTD_DUBT_findBestMatch (%u) ", current);
260  assert(ip <= iend-8); /* required for h calculation */
261 
262  /* reach end of unsorted candidates list */
263  while ( (matchIndex > unsortLimit)
264  && (*unsortedMark == ZSTD_DUBT_UNSORTED_MARK)
265  && (nbCandidates > 1) ) {
266  DEBUGLOG(8, "ZSTD_DUBT_findBestMatch: candidate %u is unsorted",
267  matchIndex);
268  *unsortedMark = previousCandidate; /* the unsortedMark becomes a reversed chain, to move up back to original position */
269  previousCandidate = matchIndex;
270  matchIndex = *nextCandidate;
271  nextCandidate = bt + 2*(matchIndex&btMask);
272  unsortedMark = bt + 2*(matchIndex&btMask) + 1;
273  nbCandidates --;
274  }
275 
276  /* nullify last candidate if it's still unsorted
277  * simplification, detrimental to compression ratio, beneficial for speed */
278  if ( (matchIndex > unsortLimit)
279  && (*unsortedMark==ZSTD_DUBT_UNSORTED_MARK) ) {
280  DEBUGLOG(7, "ZSTD_DUBT_findBestMatch: nullify last unsorted candidate %u",
281  matchIndex);
282  *nextCandidate = *unsortedMark = 0;
283  }
284 
285  /* batch sort stacked candidates */
286  matchIndex = previousCandidate;
287  while (matchIndex) { /* will end on matchIndex == 0 */
288  U32* const nextCandidateIdxPtr = bt + 2*(matchIndex&btMask) + 1;
289  U32 const nextCandidateIdx = *nextCandidateIdxPtr;
290  ZSTD_insertDUBT1(ms, matchIndex, iend,
291  nbCandidates, unsortLimit, dictMode);
292  matchIndex = nextCandidateIdx;
293  nbCandidates++;
294  }
295 
296  /* find longest match */
297  { size_t commonLengthSmaller = 0, commonLengthLarger = 0;
298  const BYTE* const dictBase = ms->window.dictBase;
299  const U32 dictLimit = ms->window.dictLimit;
300  const BYTE* const dictEnd = dictBase + dictLimit;
301  const BYTE* const prefixStart = base + dictLimit;
302  U32* smallerPtr = bt + 2*(current&btMask);
303  U32* largerPtr = bt + 2*(current&btMask) + 1;
304  U32 matchEndIdx = current + 8 + 1;
305  U32 dummy32; /* to be nullified at the end */
306  size_t bestLength = 0;
307 
308  matchIndex = hashTable[h];
309  hashTable[h] = current; /* Update Hash Table */
310 
311  while (nbCompares-- && (matchIndex > windowLow)) {
312  U32* const nextPtr = bt + 2*(matchIndex & btMask);
313  size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
314  const BYTE* match;
315 
316  if ((dictMode != ZSTD_extDict) || (matchIndex+matchLength >= dictLimit)) {
317  match = base + matchIndex;
318  matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend);
319  } else {
320  match = dictBase + matchIndex;
321  matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart);
322  if (matchIndex+matchLength >= dictLimit)
323  match = base + matchIndex; /* to prepare for next usage of match[matchLength] */
324  }
325 
326  if (matchLength > bestLength) {
327  if (matchLength > matchEndIdx - matchIndex)
328  matchEndIdx = matchIndex + (U32)matchLength;
329  if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit32(current-matchIndex+1) - ZSTD_highbit32((U32)offsetPtr[0]+1)) )
330  bestLength = matchLength, *offsetPtr = ZSTD_REP_MOVE + current - matchIndex;
331  if (ip+matchLength == iend) { /* equal : no way to know if inf or sup */
332  if (dictMode == ZSTD_dictMatchState) {
333  nbCompares = 0; /* in addition to avoiding checking any
334  * further in this loop, make sure we
335  * skip checking in the dictionary. */
336  }
337  break; /* drop, to guarantee consistency (miss a little bit of compression) */
338  }
339  }
340 
341  if (match[matchLength] < ip[matchLength]) {
342  /* match is smaller than current */
343  *smallerPtr = matchIndex; /* update smaller idx */
344  commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
345  if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */
346  smallerPtr = nextPtr+1; /* new "smaller" => larger of match */
347  matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */
348  } else {
349  /* match is larger than current */
350  *largerPtr = matchIndex;
351  commonLengthLarger = matchLength;
352  if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */
353  largerPtr = nextPtr;
354  matchIndex = nextPtr[0];
355  } }
356 
357  *smallerPtr = *largerPtr = 0;
358 
359  if (dictMode == ZSTD_dictMatchState && nbCompares) {
360  bestLength = ZSTD_DUBT_findBetterDictMatch(
361  ms, ip, iend,
362  offsetPtr, bestLength, nbCompares,
363  mls, dictMode);
364  }
365 
366  assert(matchEndIdx > current+8); /* ensure nextToUpdate is increased */
367  ms->nextToUpdate = matchEndIdx - 8; /* skip repetitive patterns */
368  if (bestLength >= MINMATCH) {
369  U32 const mIndex = current - ((U32)*offsetPtr - ZSTD_REP_MOVE); (void)mIndex;
370  DEBUGLOG(8, "ZSTD_DUBT_findBestMatch(%u) : found match of length %u and offsetCode %u (pos %u)",
371  current, (U32)bestLength, (U32)*offsetPtr, mIndex);
372  }
373  return bestLength;
374  }
375 }
376 
377 
381  const BYTE* const ip, const BYTE* const iLimit,
382  size_t* offsetPtr,
383  const U32 mls /* template */,
384  const ZSTD_dictMode_e dictMode)
385 {
386  DEBUGLOG(7, "ZSTD_BtFindBestMatch");
387  if (ip < ms->window.base + ms->nextToUpdate) return 0; /* skipped area */
388  ZSTD_updateDUBT(ms, ip, iLimit, mls);
389  return ZSTD_DUBT_findBestMatch(ms, ip, iLimit, offsetPtr, mls, dictMode);
390 }
391 
392 
393 static size_t
395  const BYTE* ip, const BYTE* const iLimit,
396  size_t* offsetPtr)
397 {
398  switch(ms->cParams.minMatch)
399  {
400  default : /* includes case 3 */
401  case 4 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 4, ZSTD_noDict);
402  case 5 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 5, ZSTD_noDict);
403  case 7 :
404  case 6 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 6, ZSTD_noDict);
405  }
406 }
407 
408 
410  ZSTD_matchState_t* ms,
411  const BYTE* ip, const BYTE* const iLimit,
412  size_t* offsetPtr)
413 {
414  switch(ms->cParams.minMatch)
415  {
416  default : /* includes case 3 */
417  case 4 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 4, ZSTD_dictMatchState);
418  case 5 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 5, ZSTD_dictMatchState);
419  case 7 :
420  case 6 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 6, ZSTD_dictMatchState);
421  }
422 }
423 
424 
426  ZSTD_matchState_t* ms,
427  const BYTE* ip, const BYTE* const iLimit,
428  size_t* offsetPtr)
429 {
430  switch(ms->cParams.minMatch)
431  {
432  default : /* includes case 3 */
433  case 4 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 4, ZSTD_extDict);
434  case 5 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 5, ZSTD_extDict);
435  case 7 :
436  case 6 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 6, ZSTD_extDict);
437  }
438 }
439 
440 
441 
442 /* *********************************
443 * Hash Chain
444 ***********************************/
445 #define NEXT_IN_CHAIN(d, mask) chainTable[(d) & (mask)]
446 
447 /* Update chains up to ip (excluded)
448  Assumption : always within prefix (i.e. not within extDict) */
450  ZSTD_matchState_t* ms,
451  const ZSTD_compressionParameters* const cParams,
452  const BYTE* ip, U32 const mls)
453 {
454  U32* const hashTable = ms->hashTable;
455  const U32 hashLog = cParams->hashLog;
456  U32* const chainTable = ms->chainTable;
457  const U32 chainMask = (1 << cParams->chainLog) - 1;
458  const BYTE* const base = ms->window.base;
459  const U32 target = (U32)(ip - base);
460  U32 idx = ms->nextToUpdate;
461 
462  while(idx < target) { /* catch up */
463  size_t const h = ZSTD_hashPtr(base+idx, hashLog, mls);
464  NEXT_IN_CHAIN(idx, chainMask) = hashTable[h];
465  hashTable[h] = idx;
466  idx++;
467  }
468 
469  ms->nextToUpdate = target;
470  return hashTable[ZSTD_hashPtr(ip, hashLog, mls)];
471 }
472 
474  const ZSTD_compressionParameters* const cParams = &ms->cParams;
475  return ZSTD_insertAndFindFirstIndex_internal(ms, cParams, ip, ms->cParams.minMatch);
476 }
477 
478 
479 /* inlining is important to hardwire a hot branch (template emulation) */
482  ZSTD_matchState_t* ms,
483  const BYTE* const ip, const BYTE* const iLimit,
484  size_t* offsetPtr,
485  const U32 mls, const ZSTD_dictMode_e dictMode)
486 {
487  const ZSTD_compressionParameters* const cParams = &ms->cParams;
488  U32* const chainTable = ms->chainTable;
489  const U32 chainSize = (1 << cParams->chainLog);
490  const U32 chainMask = chainSize-1;
491  const BYTE* const base = ms->window.base;
492  const BYTE* const dictBase = ms->window.dictBase;
493  const U32 dictLimit = ms->window.dictLimit;
494  const BYTE* const prefixStart = base + dictLimit;
495  const BYTE* const dictEnd = dictBase + dictLimit;
496  const U32 current = (U32)(ip-base);
497  const U32 maxDistance = 1U << cParams->windowLog;
498  const U32 lowestValid = ms->window.lowLimit;
499  const U32 withinMaxDistance = (current - lowestValid > maxDistance) ? current - maxDistance : lowestValid;
500  const U32 isDictionary = (ms->loadedDictEnd != 0);
501  const U32 lowLimit = isDictionary ? lowestValid : withinMaxDistance;
502  const U32 minChain = current > chainSize ? current - chainSize : 0;
503  U32 nbAttempts = 1U << cParams->searchLog;
504  size_t ml=4-1;
505 
506  /* HC4 match finder */
507  U32 matchIndex = ZSTD_insertAndFindFirstIndex_internal(ms, cParams, ip, mls);
508 
509  for ( ; (matchIndex>lowLimit) & (nbAttempts>0) ; nbAttempts--) {
510  size_t currentMl=0;
511  if ((dictMode != ZSTD_extDict) || matchIndex >= dictLimit) {
512  const BYTE* const match = base + matchIndex;
513  assert(matchIndex >= dictLimit); /* ensures this is true if dictMode != ZSTD_extDict */
514  if (match[ml] == ip[ml]) /* potentially better */
515  currentMl = ZSTD_count(ip, match, iLimit);
516  } else {
517  const BYTE* const match = dictBase + matchIndex;
518  assert(match+4 <= dictEnd);
519  if (MEM_read32(match) == MEM_read32(ip)) /* assumption : matchIndex <= dictLimit-4 (by table construction) */
520  currentMl = ZSTD_count_2segments(ip+4, match+4, iLimit, dictEnd, prefixStart) + 4;
521  }
522 
523  /* save best solution */
524  if (currentMl > ml) {
525  ml = currentMl;
526  *offsetPtr = current - matchIndex + ZSTD_REP_MOVE;
527  if (ip+currentMl == iLimit) break; /* best possible, avoids read overflow on next attempt */
528  }
529 
530  if (matchIndex <= minChain) break;
531  matchIndex = NEXT_IN_CHAIN(matchIndex, chainMask);
532  }
533 
534  if (dictMode == ZSTD_dictMatchState) {
535  const ZSTD_matchState_t* const dms = ms->dictMatchState;
536  const U32* const dmsChainTable = dms->chainTable;
537  const U32 dmsChainSize = (1 << dms->cParams.chainLog);
538  const U32 dmsChainMask = dmsChainSize - 1;
539  const U32 dmsLowestIndex = dms->window.dictLimit;
540  const BYTE* const dmsBase = dms->window.base;
541  const BYTE* const dmsEnd = dms->window.nextSrc;
542  const U32 dmsSize = (U32)(dmsEnd - dmsBase);
543  const U32 dmsIndexDelta = dictLimit - dmsSize;
544  const U32 dmsMinChain = dmsSize > dmsChainSize ? dmsSize - dmsChainSize : 0;
545 
546  matchIndex = dms->hashTable[ZSTD_hashPtr(ip, dms->cParams.hashLog, mls)];
547 
548  for ( ; (matchIndex>dmsLowestIndex) & (nbAttempts>0) ; nbAttempts--) {
549  size_t currentMl=0;
550  const BYTE* const match = dmsBase + matchIndex;
551  assert(match+4 <= dmsEnd);
552  if (MEM_read32(match) == MEM_read32(ip)) /* assumption : matchIndex <= dictLimit-4 (by table construction) */
553  currentMl = ZSTD_count_2segments(ip+4, match+4, iLimit, dmsEnd, prefixStart) + 4;
554 
555  /* save best solution */
556  if (currentMl > ml) {
557  ml = currentMl;
558  *offsetPtr = current - (matchIndex + dmsIndexDelta) + ZSTD_REP_MOVE;
559  if (ip+currentMl == iLimit) break; /* best possible, avoids read overflow on next attempt */
560  }
561 
562  if (matchIndex <= dmsMinChain) break;
563  matchIndex = dmsChainTable[matchIndex & dmsChainMask];
564  }
565  }
566 
567  return ml;
568 }
569 
570 
572  ZSTD_matchState_t* ms,
573  const BYTE* ip, const BYTE* const iLimit,
574  size_t* offsetPtr)
575 {
576  switch(ms->cParams.minMatch)
577  {
578  default : /* includes case 3 */
579  case 4 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, ZSTD_noDict);
580  case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_noDict);
581  case 7 :
582  case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_noDict);
583  }
584 }
585 
586 
588  ZSTD_matchState_t* ms,
589  const BYTE* ip, const BYTE* const iLimit,
590  size_t* offsetPtr)
591 {
592  switch(ms->cParams.minMatch)
593  {
594  default : /* includes case 3 */
595  case 4 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, ZSTD_dictMatchState);
596  case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_dictMatchState);
597  case 7 :
598  case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_dictMatchState);
599  }
600 }
601 
602 
604  ZSTD_matchState_t* ms,
605  const BYTE* ip, const BYTE* const iLimit,
606  size_t* offsetPtr)
607 {
608  switch(ms->cParams.minMatch)
609  {
610  default : /* includes case 3 */
611  case 4 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, ZSTD_extDict);
612  case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_extDict);
613  case 7 :
614  case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_extDict);
615  }
616 }
617 
618 
619 /* *******************************
620 * Common parser - lazy strategy
621 *********************************/
623 
624 size_t
626  ZSTD_matchState_t* ms, seqStore_t* seqStore,
627  U32 rep[ZSTD_REP_NUM],
628  const void* src, size_t srcSize,
629  const searchMethod_e searchMethod, const U32 depth,
630  ZSTD_dictMode_e const dictMode)
631 {
632  const BYTE* const istart = (const BYTE*)src;
633  const BYTE* ip = istart;
634  const BYTE* anchor = istart;
635  const BYTE* const iend = istart + srcSize;
636  const BYTE* const ilimit = iend - 8;
637  const BYTE* const base = ms->window.base;
638  const U32 prefixLowestIndex = ms->window.dictLimit;
639  const BYTE* const prefixLowest = base + prefixLowestIndex;
640 
641  typedef size_t (*searchMax_f)(
642  ZSTD_matchState_t* ms,
643  const BYTE* ip, const BYTE* iLimit, size_t* offsetPtr);
644  searchMax_f const searchMax = dictMode == ZSTD_dictMatchState ?
649  U32 offset_1 = rep[0], offset_2 = rep[1], savedOffset=0;
650 
651  const ZSTD_matchState_t* const dms = ms->dictMatchState;
652  const U32 dictLowestIndex = dictMode == ZSTD_dictMatchState ?
653  dms->window.dictLimit : 0;
654  const BYTE* const dictBase = dictMode == ZSTD_dictMatchState ?
655  dms->window.base : NULL;
656  const BYTE* const dictLowest = dictMode == ZSTD_dictMatchState ?
657  dictBase + dictLowestIndex : NULL;
658  const BYTE* const dictEnd = dictMode == ZSTD_dictMatchState ?
659  dms->window.nextSrc : NULL;
660  const U32 dictIndexDelta = dictMode == ZSTD_dictMatchState ?
661  prefixLowestIndex - (U32)(dictEnd - dictBase) :
662  0;
663  const U32 dictAndPrefixLength = (U32)((ip - prefixLowest) + (dictEnd - dictLowest));
664 
665  DEBUGLOG(5, "ZSTD_compressBlock_lazy_generic (dictMode=%u)", (U32)dictMode);
666 
667  /* init */
668  ip += (dictAndPrefixLength == 0);
669  if (dictMode == ZSTD_noDict) {
670  U32 const current = (U32)(ip - base);
671  U32 const windowLow = ZSTD_getLowestPrefixIndex(ms, current, ms->cParams.windowLog);
672  U32 const maxRep = current - windowLow;
673  if (offset_2 > maxRep) savedOffset = offset_2, offset_2 = 0;
674  if (offset_1 > maxRep) savedOffset = offset_1, offset_1 = 0;
675  }
676  if (dictMode == ZSTD_dictMatchState) {
677  /* dictMatchState repCode checks don't currently handle repCode == 0
678  * disabling. */
679  assert(offset_1 <= dictAndPrefixLength);
680  assert(offset_2 <= dictAndPrefixLength);
681  }
682 
683  /* Match Loop */
684 #if defined(__GNUC__) && defined(__x86_64__)
685  /* I've measured random a 5% speed loss on levels 5 & 6 (greedy) when the
686  * code alignment is perturbed. To fix the instability align the loop on 32-bytes.
687  */
688  __asm__(".p2align 5");
689 #endif
690  while (ip < ilimit) {
691  size_t matchLength=0;
692  size_t offset=0;
693  const BYTE* start=ip+1;
694 
695  /* check repCode */
696  if (dictMode == ZSTD_dictMatchState) {
697  const U32 repIndex = (U32)(ip - base) + 1 - offset_1;
698  const BYTE* repMatch = (dictMode == ZSTD_dictMatchState
699  && repIndex < prefixLowestIndex) ?
700  dictBase + (repIndex - dictIndexDelta) :
701  base + repIndex;
702  if (((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
703  && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
704  const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
705  matchLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
706  if (depth==0) goto _storeSequence;
707  }
708  }
709  if ( dictMode == ZSTD_noDict
710  && ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1)))) {
711  matchLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
712  if (depth==0) goto _storeSequence;
713  }
714 
715  /* first search (depth 0) */
716  { size_t offsetFound = 999999999;
717  size_t const ml2 = searchMax(ms, ip, iend, &offsetFound);
718  if (ml2 > matchLength)
719  matchLength = ml2, start = ip, offset=offsetFound;
720  }
721 
722  if (matchLength < 4) {
723  ip += ((ip-anchor) >> kSearchStrength) + 1; /* jump faster over incompressible sections */
724  continue;
725  }
726 
727  /* let's try to find a better solution */
728  if (depth>=1)
729  while (ip<ilimit) {
730  ip ++;
731  if ( (dictMode == ZSTD_noDict)
732  && (offset) && ((offset_1>0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
733  size_t const mlRep = ZSTD_count(ip+4, ip+4-offset_1, iend) + 4;
734  int const gain2 = (int)(mlRep * 3);
735  int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
736  if ((mlRep >= 4) && (gain2 > gain1))
737  matchLength = mlRep, offset = 0, start = ip;
738  }
739  if (dictMode == ZSTD_dictMatchState) {
740  const U32 repIndex = (U32)(ip - base) - offset_1;
741  const BYTE* repMatch = repIndex < prefixLowestIndex ?
742  dictBase + (repIndex - dictIndexDelta) :
743  base + repIndex;
744  if (((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
745  && (MEM_read32(repMatch) == MEM_read32(ip)) ) {
746  const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
747  size_t const mlRep = ZSTD_count_2segments(ip+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
748  int const gain2 = (int)(mlRep * 3);
749  int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
750  if ((mlRep >= 4) && (gain2 > gain1))
751  matchLength = mlRep, offset = 0, start = ip;
752  }
753  }
754  { size_t offset2=999999999;
755  size_t const ml2 = searchMax(ms, ip, iend, &offset2);
756  int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
757  int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 4);
758  if ((ml2 >= 4) && (gain2 > gain1)) {
759  matchLength = ml2, offset = offset2, start = ip;
760  continue; /* search a better one */
761  } }
762 
763  /* let's find an even better one */
764  if ((depth==2) && (ip<ilimit)) {
765  ip ++;
766  if ( (dictMode == ZSTD_noDict)
767  && (offset) && ((offset_1>0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
768  size_t const mlRep = ZSTD_count(ip+4, ip+4-offset_1, iend) + 4;
769  int const gain2 = (int)(mlRep * 4);
770  int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
771  if ((mlRep >= 4) && (gain2 > gain1))
772  matchLength = mlRep, offset = 0, start = ip;
773  }
774  if (dictMode == ZSTD_dictMatchState) {
775  const U32 repIndex = (U32)(ip - base) - offset_1;
776  const BYTE* repMatch = repIndex < prefixLowestIndex ?
777  dictBase + (repIndex - dictIndexDelta) :
778  base + repIndex;
779  if (((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
780  && (MEM_read32(repMatch) == MEM_read32(ip)) ) {
781  const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
782  size_t const mlRep = ZSTD_count_2segments(ip+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
783  int const gain2 = (int)(mlRep * 4);
784  int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
785  if ((mlRep >= 4) && (gain2 > gain1))
786  matchLength = mlRep, offset = 0, start = ip;
787  }
788  }
789  { size_t offset2=999999999;
790  size_t const ml2 = searchMax(ms, ip, iend, &offset2);
791  int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
792  int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 7);
793  if ((ml2 >= 4) && (gain2 > gain1)) {
794  matchLength = ml2, offset = offset2, start = ip;
795  continue;
796  } } }
797  break; /* nothing found : store previous solution */
798  }
799 
800  /* NOTE:
801  * start[-offset+ZSTD_REP_MOVE-1] is undefined behavior.
802  * (-offset+ZSTD_REP_MOVE-1) is unsigned, and is added to start, which
803  * overflows the pointer, which is undefined behavior.
804  */
805  /* catch up */
806  if (offset) {
807  if (dictMode == ZSTD_noDict) {
808  while ( ((start > anchor) & (start - (offset-ZSTD_REP_MOVE) > prefixLowest))
809  && (start[-1] == (start-(offset-ZSTD_REP_MOVE))[-1]) ) /* only search for offset within prefix */
810  { start--; matchLength++; }
811  }
812  if (dictMode == ZSTD_dictMatchState) {
813  U32 const matchIndex = (U32)((start-base) - (offset - ZSTD_REP_MOVE));
814  const BYTE* match = (matchIndex < prefixLowestIndex) ? dictBase + matchIndex - dictIndexDelta : base + matchIndex;
815  const BYTE* const mStart = (matchIndex < prefixLowestIndex) ? dictLowest : prefixLowest;
816  while ((start>anchor) && (match>mStart) && (start[-1] == match[-1])) { start--; match--; matchLength++; } /* catch up */
817  }
818  offset_2 = offset_1; offset_1 = (U32)(offset - ZSTD_REP_MOVE);
819  }
820  /* store sequence */
821 _storeSequence:
822  { size_t const litLength = start - anchor;
823  ZSTD_storeSeq(seqStore, litLength, anchor, iend, (U32)offset, matchLength-MINMATCH);
824  anchor = ip = start + matchLength;
825  }
826 
827  /* check immediate repcode */
828  if (dictMode == ZSTD_dictMatchState) {
829  while (ip <= ilimit) {
830  U32 const current2 = (U32)(ip-base);
831  U32 const repIndex = current2 - offset_2;
832  const BYTE* repMatch = dictMode == ZSTD_dictMatchState
833  && repIndex < prefixLowestIndex ?
834  dictBase - dictIndexDelta + repIndex :
835  base + repIndex;
836  if ( ((U32)((prefixLowestIndex-1) - (U32)repIndex) >= 3 /* intentional overflow */)
837  && (MEM_read32(repMatch) == MEM_read32(ip)) ) {
838  const BYTE* const repEnd2 = repIndex < prefixLowestIndex ? dictEnd : iend;
839  matchLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd2, prefixLowest) + 4;
840  offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap offset_2 <=> offset_1 */
841  ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, matchLength-MINMATCH);
842  ip += matchLength;
843  anchor = ip;
844  continue;
845  }
846  break;
847  }
848  }
849 
850  if (dictMode == ZSTD_noDict) {
851  while ( ((ip <= ilimit) & (offset_2>0))
852  && (MEM_read32(ip) == MEM_read32(ip - offset_2)) ) {
853  /* store sequence */
854  matchLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
855  offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap repcodes */
856  ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, matchLength-MINMATCH);
857  ip += matchLength;
858  anchor = ip;
859  continue; /* faster when present ... (?) */
860  } } }
861 
862  /* Save reps for next block */
863  rep[0] = offset_1 ? offset_1 : savedOffset;
864  rep[1] = offset_2 ? offset_2 : savedOffset;
865 
866  /* Return the last literals size */
867  return (size_t)(iend - anchor);
868 }
869 
870 
872  ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
873  void const* src, size_t srcSize)
874 {
875  return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, search_binaryTree, 2, ZSTD_noDict);
876 }
877 
879  ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
880  void const* src, size_t srcSize)
881 {
882  return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 2, ZSTD_noDict);
883 }
884 
886  ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
887  void const* src, size_t srcSize)
888 {
889  return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 1, ZSTD_noDict);
890 }
891 
893  ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
894  void const* src, size_t srcSize)
895 {
896  return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 0, ZSTD_noDict);
897 }
898 
900  ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
901  void const* src, size_t srcSize)
902 {
903  return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, search_binaryTree, 2, ZSTD_dictMatchState);
904 }
905 
907  ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
908  void const* src, size_t srcSize)
909 {
910  return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 2, ZSTD_dictMatchState);
911 }
912 
914  ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
915  void const* src, size_t srcSize)
916 {
917  return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 1, ZSTD_dictMatchState);
918 }
919 
921  ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
922  void const* src, size_t srcSize)
923 {
924  return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 0, ZSTD_dictMatchState);
925 }
926 
927 
930  ZSTD_matchState_t* ms, seqStore_t* seqStore,
931  U32 rep[ZSTD_REP_NUM],
932  const void* src, size_t srcSize,
933  const searchMethod_e searchMethod, const U32 depth)
934 {
935  const BYTE* const istart = (const BYTE*)src;
936  const BYTE* ip = istart;
937  const BYTE* anchor = istart;
938  const BYTE* const iend = istart + srcSize;
939  const BYTE* const ilimit = iend - 8;
940  const BYTE* const base = ms->window.base;
941  const U32 dictLimit = ms->window.dictLimit;
942  const BYTE* const prefixStart = base + dictLimit;
943  const BYTE* const dictBase = ms->window.dictBase;
944  const BYTE* const dictEnd = dictBase + dictLimit;
945  const BYTE* const dictStart = dictBase + ms->window.lowLimit;
946  const U32 windowLog = ms->cParams.windowLog;
947 
948  typedef size_t (*searchMax_f)(
949  ZSTD_matchState_t* ms,
950  const BYTE* ip, const BYTE* iLimit, size_t* offsetPtr);
952 
953  U32 offset_1 = rep[0], offset_2 = rep[1];
954 
955  DEBUGLOG(5, "ZSTD_compressBlock_lazy_extDict_generic");
956 
957  /* init */
958  ip += (ip == prefixStart);
959 
960  /* Match Loop */
961 #if defined(__GNUC__) && defined(__x86_64__)
962  /* I've measured random a 5% speed loss on levels 5 & 6 (greedy) when the
963  * code alignment is perturbed. To fix the instability align the loop on 32-bytes.
964  */
965  __asm__(".p2align 5");
966 #endif
967  while (ip < ilimit) {
968  size_t matchLength=0;
969  size_t offset=0;
970  const BYTE* start=ip+1;
971  U32 current = (U32)(ip-base);
972 
973  /* check repCode */
974  { const U32 windowLow = ZSTD_getLowestMatchIndex(ms, current+1, windowLog);
975  const U32 repIndex = (U32)(current+1 - offset_1);
976  const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
977  const BYTE* const repMatch = repBase + repIndex;
978  if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > windowLow)) /* intentional overflow */
979  if (MEM_read32(ip+1) == MEM_read32(repMatch)) {
980  /* repcode detected we should take it */
981  const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
982  matchLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repEnd, prefixStart) + 4;
983  if (depth==0) goto _storeSequence;
984  } }
985 
986  /* first search (depth 0) */
987  { size_t offsetFound = 999999999;
988  size_t const ml2 = searchMax(ms, ip, iend, &offsetFound);
989  if (ml2 > matchLength)
990  matchLength = ml2, start = ip, offset=offsetFound;
991  }
992 
993  if (matchLength < 4) {
994  ip += ((ip-anchor) >> kSearchStrength) + 1; /* jump faster over incompressible sections */
995  continue;
996  }
997 
998  /* let's try to find a better solution */
999  if (depth>=1)
1000  while (ip<ilimit) {
1001  ip ++;
1002  current++;
1003  /* check repCode */
1004  if (offset) {
1005  const U32 windowLow = ZSTD_getLowestMatchIndex(ms, current, windowLog);
1006  const U32 repIndex = (U32)(current - offset_1);
1007  const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
1008  const BYTE* const repMatch = repBase + repIndex;
1009  if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > windowLow)) /* intentional overflow */
1010  if (MEM_read32(ip) == MEM_read32(repMatch)) {
1011  /* repcode detected */
1012  const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
1013  size_t const repLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4;
1014  int const gain2 = (int)(repLength * 3);
1015  int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
1016  if ((repLength >= 4) && (gain2 > gain1))
1017  matchLength = repLength, offset = 0, start = ip;
1018  } }
1019 
1020  /* search match, depth 1 */
1021  { size_t offset2=999999999;
1022  size_t const ml2 = searchMax(ms, ip, iend, &offset2);
1023  int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
1024  int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 4);
1025  if ((ml2 >= 4) && (gain2 > gain1)) {
1026  matchLength = ml2, offset = offset2, start = ip;
1027  continue; /* search a better one */
1028  } }
1029 
1030  /* let's find an even better one */
1031  if ((depth==2) && (ip<ilimit)) {
1032  ip ++;
1033  current++;
1034  /* check repCode */
1035  if (offset) {
1036  const U32 windowLow = ZSTD_getLowestMatchIndex(ms, current, windowLog);
1037  const U32 repIndex = (U32)(current - offset_1);
1038  const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
1039  const BYTE* const repMatch = repBase + repIndex;
1040  if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > windowLow)) /* intentional overflow */
1041  if (MEM_read32(ip) == MEM_read32(repMatch)) {
1042  /* repcode detected */
1043  const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
1044  size_t const repLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4;
1045  int const gain2 = (int)(repLength * 4);
1046  int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
1047  if ((repLength >= 4) && (gain2 > gain1))
1048  matchLength = repLength, offset = 0, start = ip;
1049  } }
1050 
1051  /* search match, depth 2 */
1052  { size_t offset2=999999999;
1053  size_t const ml2 = searchMax(ms, ip, iend, &offset2);
1054  int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
1055  int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 7);
1056  if ((ml2 >= 4) && (gain2 > gain1)) {
1057  matchLength = ml2, offset = offset2, start = ip;
1058  continue;
1059  } } }
1060  break; /* nothing found : store previous solution */
1061  }
1062 
1063  /* catch up */
1064  if (offset) {
1065  U32 const matchIndex = (U32)((start-base) - (offset - ZSTD_REP_MOVE));
1066  const BYTE* match = (matchIndex < dictLimit) ? dictBase + matchIndex : base + matchIndex;
1067  const BYTE* const mStart = (matchIndex < dictLimit) ? dictStart : prefixStart;
1068  while ((start>anchor) && (match>mStart) && (start[-1] == match[-1])) { start--; match--; matchLength++; } /* catch up */
1069  offset_2 = offset_1; offset_1 = (U32)(offset - ZSTD_REP_MOVE);
1070  }
1071 
1072  /* store sequence */
1073 _storeSequence:
1074  { size_t const litLength = start - anchor;
1075  ZSTD_storeSeq(seqStore, litLength, anchor, iend, (U32)offset, matchLength-MINMATCH);
1076  anchor = ip = start + matchLength;
1077  }
1078 
1079  /* check immediate repcode */
1080  while (ip <= ilimit) {
1081  const U32 repCurrent = (U32)(ip-base);
1082  const U32 windowLow = ZSTD_getLowestMatchIndex(ms, repCurrent, windowLog);
1083  const U32 repIndex = repCurrent - offset_2;
1084  const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
1085  const BYTE* const repMatch = repBase + repIndex;
1086  if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > windowLow)) /* intentional overflow */
1087  if (MEM_read32(ip) == MEM_read32(repMatch)) {
1088  /* repcode detected we should take it */
1089  const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
1090  matchLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4;
1091  offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap offset history */
1092  ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, matchLength-MINMATCH);
1093  ip += matchLength;
1094  anchor = ip;
1095  continue; /* faster when present ... (?) */
1096  }
1097  break;
1098  } }
1099 
1100  /* Save reps for next block */
1101  rep[0] = offset_1;
1102  rep[1] = offset_2;
1103 
1104  /* Return the last literals size */
1105  return (size_t)(iend - anchor);
1106 }
1107 
1108 
1110  ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
1111  void const* src, size_t srcSize)
1112 {
1113  return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 0);
1114 }
1115 
1117  ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
1118  void const* src, size_t srcSize)
1119 
1120 {
1121  return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 1);
1122 }
1123 
1125  ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
1126  void const* src, size_t srcSize)
1127 
1128 {
1129  return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 2);
1130 }
1131 
1133  ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
1134  void const* src, size_t srcSize)
1135 
1136 {
1137  return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, search_binaryTree, 2);
1138 }
#define kSearchStrength
size_t ZSTD_compressBlock_lazy_dictMatchState(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)
Definition: zstd_lazy.c:913
struct png_info_def **typedef void(__cdecl typeof(png_destroy_read_struct))(struct png_struct_def **
Definition: typeof.h:49
Definition: match.c:28
static size_t ZSTD_HcFindBestMatch_dictMatchState_selectMLS(ZSTD_matchState_t *ms, const BYTE *ip, const BYTE *const iLimit, size_t *offsetPtr)
Definition: zstd_lazy.c:587
U32 ZSTD_insertAndFindFirstIndex(ZSTD_matchState_t *ms, const BYTE *ip)
Definition: zstd_lazy.c:473
HINT_INLINE UNUSED_ATTR void ZSTD_storeSeq(seqStore_t *seqStorePtr, size_t litLength, const BYTE *literals, const BYTE *litLimit, U32 offCode, size_t mlBase)
#define U(x)
Definition: wordpad.c:45
#define assert(x)
Definition: debug.h:53
size_t ZSTD_compressBlock_lazy2_dictMatchState(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)
Definition: zstd_lazy.c:906
__asm__("\n\t \ NewInt3Handler:\n\t \ pushl $" STR(REASON_INT3) "\n\t \ // call debugger loop\n\t \ jmp NewInt31Handler\n\t \ ")
searchMethod_e
Definition: zstd_lazy.c:622
static U32 ZSTD_insertAndFindFirstIndex_internal(ZSTD_matchState_t *ms, const ZSTD_compressionParameters *const cParams, const BYTE *ip, U32 const mls)
Definition: zstd_lazy.c:449
void mls(int argc, const char *argv[])
Definition: cmds.c:1168
GLfloat GLfloat GLfloat GLfloat h
Definition: glext.h:7723
T MIN(T a, T b)
Definition: polytest.cpp:79
#define DEBUGLOG(l,...)
Definition: debug.h:106
MEM_STATIC U32 ZSTD_getLowestMatchIndex(const ZSTD_matchState_t *ms, U32 current, unsigned windowLog)
size_t ZSTD_compressBlock_btlazy2_extDict(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)
Definition: zstd_lazy.c:1132
GLuint base
Definition: 3dtext.c:35
size_t ZSTD_compressBlock_lazy(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)
Definition: zstd_lazy.c:885
size_t ZSTD_compressBlock_lazy2(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)
Definition: zstd_lazy.c:878
int ip[4]
Definition: rtl.c:1176
unsigned int idx
Definition: utils.c:41
ZSTD_compressionParameters cParams
#define NEXT_IN_CHAIN(d, mask)
Definition: zstd_lazy.c:445
static size_t ZSTD_BtFindBestMatch_extDict_selectMLS(ZSTD_matchState_t *ms, const BYTE *ip, const BYTE *const iLimit, size_t *offsetPtr)
Definition: zstd_lazy.c:425
struct match match
Definition: match.c:33
MEM_STATIC size_t ZSTD_count(const BYTE *pIn, const BYTE *pMatch, const BYTE *const pInLimit)
MEM_STATIC size_t ZSTD_count_2segments(const BYTE *ip, const BYTE *match, const BYTE *iEnd, const BYTE *mEnd, const BYTE *iStart)
#define ZSTD_REP_MOVE
MEM_STATIC U32 ZSTD_getLowestPrefixIndex(const ZSTD_matchState_t *ms, U32 current, unsigned windowLog)
__kernel_size_t size_t
Definition: linux.h:237
FORCE_INLINE_TEMPLATE size_t ZSTD_HcFindBestMatch_selectMLS(ZSTD_matchState_t *ms, const BYTE *ip, const BYTE *const iLimit, size_t *offsetPtr)
Definition: zstd_lazy.c:571
static void ZSTD_insertDUBT1(ZSTD_matchState_t *ms, U32 current, const BYTE *inputEnd, U32 nbCompares, U32 btLow, const ZSTD_dictMode_e dictMode)
Definition: zstd_lazy.c:64
Definition: dhcpd.h:61
size_t ZSTD_compressBlock_btlazy2_dictMatchState(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)
Definition: zstd_lazy.c:899
const ZSTD_matchState_t * dictMatchState
#define ZSTD_DUBT_UNSORTED_MARK
GLintptr offset
Definition: glext.h:5920
struct task_struct * current
Definition: linux.c:32
static void ZSTD_updateDUBT(ZSTD_matchState_t *ms, const BYTE *ip, const BYTE *iend, U32 mls)
Definition: zstd_lazy.c:20
GLint GLint GLsizei GLsizei GLsizei depth
Definition: gl.h:1546
MEM_STATIC U32 MEM_read32(const void *memPtr)
Definition: mem.h:242
static size_t ZSTD_DUBT_findBetterDictMatch(ZSTD_matchState_t *ms, const BYTE *const ip, const BYTE *const iend, size_t *offsetPtr, size_t bestLength, U32 nbCompares, U32 const mls, const ZSTD_dictMode_e dictMode)
Definition: zstd_lazy.c:153
size_t ZSTD_compressBlock_greedy(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)
Definition: zstd_lazy.c:892
static size_t ZSTD_DUBT_findBestMatch(ZSTD_matchState_t *ms, const BYTE *const ip, const BYTE *const iend, size_t *offsetPtr, U32 const mls, const ZSTD_dictMode_e dictMode)
Definition: zstd_lazy.c:231
GLenum src
Definition: glext.h:6340
static IHTMLWindow2 * window
Definition: events.c:77
unsigned char BYTE
Definition: xxhash.c:193
FORCE_INLINE_TEMPLATE size_t ZSTD_compressBlock_lazy_extDict_generic(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], const void *src, size_t srcSize, const searchMethod_e searchMethod, const U32 depth)
Definition: zstd_lazy.c:929
T MAX(T a, T b)
Definition: polytest.cpp:85
MEM_STATIC size_t ZSTD_hashPtr(const void *p, U32 hBits, U32 mls)
size_t ZSTD_compressBlock_greedy_dictMatchState(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)
Definition: zstd_lazy.c:920
FORCE_INLINE_TEMPLATE size_t ZSTD_HcFindBestMatch_generic(ZSTD_matchState_t *ms, const BYTE *const ip, const BYTE *const iLimit, size_t *offsetPtr, const U32 mls, const ZSTD_dictMode_e dictMode)
Definition: zstd_lazy.c:481
size_t ZSTD_compressBlock_lazy_generic(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], const void *src, size_t srcSize, const searchMethod_e searchMethod, const U32 depth, ZSTD_dictMode_e const dictMode)
Definition: zstd_lazy.c:625
GLuint start
Definition: gl.h:1545
size_t ZSTD_compressBlock_btlazy2(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)
Definition: zstd_lazy.c:871
#define NULL
Definition: types.h:112
MEM_STATIC U32 ZSTD_highbit32(U32 val)
#define MINMATCH
GLenum target
Definition: glext.h:7315
static size_t ZSTD_BtFindBestMatch_dictMatchState_selectMLS(ZSTD_matchState_t *ms, const BYTE *ip, const BYTE *const iLimit, size_t *offsetPtr)
Definition: zstd_lazy.c:409
static size_t ZSTD_BtFindBestMatch_selectMLS(ZSTD_matchState_t *ms, const BYTE *ip, const BYTE *const iLimit, size_t *offsetPtr)
Definition: zstd_lazy.c:394
size_t ZSTD_compressBlock_greedy_extDict(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)
Definition: zstd_lazy.c:1109
FORCE_INLINE_TEMPLATE size_t ZSTD_HcFindBestMatch_extDict_selectMLS(ZSTD_matchState_t *ms, const BYTE *ip, const BYTE *const iLimit, size_t *offsetPtr)
Definition: zstd_lazy.c:603
unsigned int U32
Definition: xxhash.c:195
FORCE_INLINE_TEMPLATE size_t ZSTD_BtFindBestMatch(ZSTD_matchState_t *ms, const BYTE *const ip, const BYTE *const iLimit, size_t *offsetPtr, const U32 mls, const ZSTD_dictMode_e dictMode)
Definition: zstd_lazy.c:380
#define ZSTD_REP_NUM
size_t ZSTD_compressBlock_lazy_extDict(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)
Definition: zstd_lazy.c:1116
#define FORCE_INLINE_TEMPLATE
Definition: xxhash.c:172
unsigned int(__cdecl typeof(jpeg_read_scanlines))(struct jpeg_decompress_struct *
Definition: typeof.h:31
size_t ZSTD_compressBlock_lazy2_extDict(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)
Definition: zstd_lazy.c:1124