1/*
2 * Copyright (c) Meta Platforms, Inc. and affiliates.
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_double_fast.h"
13
14static void ZSTD_fillDoubleHashTableForCDict(ZSTD_matchState_t* ms,
15 void const* end, ZSTD_dictTableLoadMethod_e dtlm)
16{
17 const ZSTD_compressionParameters* const cParams = &ms->cParams;
18 U32* const hashLarge = ms->hashTable;
19 U32 const hBitsL = cParams->hashLog + ZSTD_SHORT_CACHE_TAG_BITS;
20 U32 const mls = cParams->minMatch;
21 U32* const hashSmall = ms->chainTable;
22 U32 const hBitsS = cParams->chainLog + ZSTD_SHORT_CACHE_TAG_BITS;
23 const BYTE* const base = ms->window.base;
24 const BYTE* ip = base + ms->nextToUpdate;
25 const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
26 const U32 fastHashFillStep = 3;
27
28 /* Always insert every fastHashFillStep position into the hash tables.
29 * Insert the other positions into the large hash table if their entry
30 * is empty.
31 */
32 for (; ip + fastHashFillStep - 1 <= iend; ip += fastHashFillStep) {
33 U32 const curr = (U32)(ip - base);
34 U32 i;
35 for (i = 0; i < fastHashFillStep; ++i) {
36 size_t const smHashAndTag = ZSTD_hashPtr(ip + i, hBitsS, mls);
37 size_t const lgHashAndTag = ZSTD_hashPtr(ip + i, hBitsL, 8);
38 if (i == 0) {
39 ZSTD_writeTaggedIndex(hashSmall, smHashAndTag, curr + i);
40 }
41 if (i == 0 || hashLarge[lgHashAndTag >> ZSTD_SHORT_CACHE_TAG_BITS] == 0) {
42 ZSTD_writeTaggedIndex(hashLarge, lgHashAndTag, curr + i);
43 }
44 /* Only load extra positions for ZSTD_dtlm_full */
45 if (dtlm == ZSTD_dtlm_fast)
46 break;
47 } }
48}
49
50static void ZSTD_fillDoubleHashTableForCCtx(ZSTD_matchState_t* ms,
51 void const* end, ZSTD_dictTableLoadMethod_e dtlm)
52{
53 const ZSTD_compressionParameters* const cParams = &ms->cParams;
54 U32* const hashLarge = ms->hashTable;
55 U32 const hBitsL = cParams->hashLog;
56 U32 const mls = cParams->minMatch;
57 U32* const hashSmall = ms->chainTable;
58 U32 const hBitsS = cParams->chainLog;
59 const BYTE* const base = ms->window.base;
60 const BYTE* ip = base + ms->nextToUpdate;
61 const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
62 const U32 fastHashFillStep = 3;
63
64 /* Always insert every fastHashFillStep position into the hash tables.
65 * Insert the other positions into the large hash table if their entry
66 * is empty.
67 */
68 for (; ip + fastHashFillStep - 1 <= iend; ip += fastHashFillStep) {
69 U32 const curr = (U32)(ip - base);
70 U32 i;
71 for (i = 0; i < fastHashFillStep; ++i) {
72 size_t const smHash = ZSTD_hashPtr(ip + i, hBitsS, mls);
73 size_t const lgHash = ZSTD_hashPtr(ip + i, hBitsL, 8);
74 if (i == 0)
75 hashSmall[smHash] = curr + i;
76 if (i == 0 || hashLarge[lgHash] == 0)
77 hashLarge[lgHash] = curr + i;
78 /* Only load extra positions for ZSTD_dtlm_full */
79 if (dtlm == ZSTD_dtlm_fast)
80 break;
81 } }
82}
83
84void ZSTD_fillDoubleHashTable(ZSTD_matchState_t* ms,
85 const void* const end,
86 ZSTD_dictTableLoadMethod_e dtlm,
87 ZSTD_tableFillPurpose_e tfp)
88{
89 if (tfp == ZSTD_tfp_forCDict) {
90 ZSTD_fillDoubleHashTableForCDict(ms, end, dtlm);
91 } else {
92 ZSTD_fillDoubleHashTableForCCtx(ms, end, dtlm);
93 }
94}
95
96
97FORCE_INLINE_TEMPLATE
98size_t ZSTD_compressBlock_doubleFast_noDict_generic(
99 ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
100 void const* src, size_t srcSize, U32 const mls /* template */)
101{
102 ZSTD_compressionParameters const* cParams = &ms->cParams;
103 U32* const hashLong = ms->hashTable;
104 const U32 hBitsL = cParams->hashLog;
105 U32* const hashSmall = ms->chainTable;
106 const U32 hBitsS = cParams->chainLog;
107 const BYTE* const base = ms->window.base;
108 const BYTE* const istart = (const BYTE*)src;
109 const BYTE* anchor = istart;
110 const U32 endIndex = (U32)((size_t)(istart - base) + srcSize);
111 /* presumes that, if there is a dictionary, it must be using Attach mode */
112 const U32 prefixLowestIndex = ZSTD_getLowestPrefixIndex(ms, endIndex, cParams->windowLog);
113 const BYTE* const prefixLowest = base + prefixLowestIndex;
114 const BYTE* const iend = istart + srcSize;
115 const BYTE* const ilimit = iend - HASH_READ_SIZE;
116 U32 offset_1=rep[0], offset_2=rep[1];
117 U32 offsetSaved1 = 0, offsetSaved2 = 0;
118
119 size_t mLength;
120 U32 offset;
121 U32 curr;
122
123 /* how many positions to search before increasing step size */
124 const size_t kStepIncr = 1 << kSearchStrength;
125 /* the position at which to increment the step size if no match is found */
126 const BYTE* nextStep;
127 size_t step; /* the current step size */
128
129 size_t hl0; /* the long hash at ip */
130 size_t hl1; /* the long hash at ip1 */
131
132 U32 idxl0; /* the long match index for ip */
133 U32 idxl1; /* the long match index for ip1 */
134
135 const BYTE* matchl0; /* the long match for ip */
136 const BYTE* matchs0; /* the short match for ip */
137 const BYTE* matchl1; /* the long match for ip1 */
138
139 const BYTE* ip = istart; /* the current position */
140 const BYTE* ip1; /* the next position */
141
142 DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_noDict_generic");
143
144 /* init */
145 ip += ((ip - prefixLowest) == 0);
146 {
147 U32 const current = (U32)(ip - base);
148 U32 const windowLow = ZSTD_getLowestPrefixIndex(ms, current, cParams->windowLog);
149 U32 const maxRep = current - windowLow;
150 if (offset_2 > maxRep) offsetSaved2 = offset_2, offset_2 = 0;
151 if (offset_1 > maxRep) offsetSaved1 = offset_1, offset_1 = 0;
152 }
153
154 /* Outer Loop: one iteration per match found and stored */
155 while (1) {
156 step = 1;
157 nextStep = ip + kStepIncr;
158 ip1 = ip + step;
159
160 if (ip1 > ilimit) {
161 goto _cleanup;
162 }
163
164 hl0 = ZSTD_hashPtr(ip, hBitsL, 8);
165 idxl0 = hashLong[hl0];
166 matchl0 = base + idxl0;
167
168 /* Inner Loop: one iteration per search / position */
169 do {
170 const size_t hs0 = ZSTD_hashPtr(ip, hBitsS, mls);
171 const U32 idxs0 = hashSmall[hs0];
172 curr = (U32)(ip-base);
173 matchs0 = base + idxs0;
174
175 hashLong[hl0] = hashSmall[hs0] = curr; /* update hash tables */
176
177 /* check noDict repcode */
178 if ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1))) {
179 mLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
180 ip++;
181 ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, REPCODE1_TO_OFFBASE, mLength);
182 goto _match_stored;
183 }
184
185 hl1 = ZSTD_hashPtr(ip1, hBitsL, 8);
186
187 if (idxl0 > prefixLowestIndex) {
188 /* check prefix long match */
189 if (MEM_read64(matchl0) == MEM_read64(ip)) {
190 mLength = ZSTD_count(ip+8, matchl0+8, iend) + 8;
191 offset = (U32)(ip-matchl0);
192 while (((ip>anchor) & (matchl0>prefixLowest)) && (ip[-1] == matchl0[-1])) { ip--; matchl0--; mLength++; } /* catch up */
193 goto _match_found;
194 }
195 }
196
197 idxl1 = hashLong[hl1];
198 matchl1 = base + idxl1;
199
200 if (idxs0 > prefixLowestIndex) {
201 /* check prefix short match */
202 if (MEM_read32(matchs0) == MEM_read32(ip)) {
203 goto _search_next_long;
204 }
205 }
206
207 if (ip1 >= nextStep) {
208 PREFETCH_L1(ip1 + 64);
209 PREFETCH_L1(ip1 + 128);
210 step++;
211 nextStep += kStepIncr;
212 }
213 ip = ip1;
214 ip1 += step;
215
216 hl0 = hl1;
217 idxl0 = idxl1;
218 matchl0 = matchl1;
219 #if defined(__aarch64__)
220 PREFETCH_L1(ip+256);
221 #endif
222 } while (ip1 <= ilimit);
223
224_cleanup:
225 /* If offset_1 started invalid (offsetSaved1 != 0) and became valid (offset_1 != 0),
226 * rotate saved offsets. See comment in ZSTD_compressBlock_fast_noDict for more context. */
227 offsetSaved2 = ((offsetSaved1 != 0) && (offset_1 != 0)) ? offsetSaved1 : offsetSaved2;
228
229 /* save reps for next block */
230 rep[0] = offset_1 ? offset_1 : offsetSaved1;
231 rep[1] = offset_2 ? offset_2 : offsetSaved2;
232
233 /* Return the last literals size */
234 return (size_t)(iend - anchor);
235
236_search_next_long:
237
238 /* check prefix long +1 match */
239 if (idxl1 > prefixLowestIndex) {
240 if (MEM_read64(matchl1) == MEM_read64(ip1)) {
241 ip = ip1;
242 mLength = ZSTD_count(ip+8, matchl1+8, iend) + 8;
243 offset = (U32)(ip-matchl1);
244 while (((ip>anchor) & (matchl1>prefixLowest)) && (ip[-1] == matchl1[-1])) { ip--; matchl1--; mLength++; } /* catch up */
245 goto _match_found;
246 }
247 }
248
249 /* if no long +1 match, explore the short match we found */
250 mLength = ZSTD_count(ip+4, matchs0+4, iend) + 4;
251 offset = (U32)(ip - matchs0);
252 while (((ip>anchor) & (matchs0>prefixLowest)) && (ip[-1] == matchs0[-1])) { ip--; matchs0--; mLength++; } /* catch up */
253
254 /* fall-through */
255
256_match_found: /* requires ip, offset, mLength */
257 offset_2 = offset_1;
258 offset_1 = offset;
259
260 if (step < 4) {
261 /* It is unsafe to write this value back to the hashtable when ip1 is
262 * greater than or equal to the new ip we will have after we're done
263 * processing this match. Rather than perform that test directly
264 * (ip1 >= ip + mLength), which costs speed in practice, we do a simpler
265 * more predictable test. The minmatch even if we take a short match is
266 * 4 bytes, so as long as step, the distance between ip and ip1
267 * (initially) is less than 4, we know ip1 < new ip. */
268 hashLong[hl1] = (U32)(ip1 - base);
269 }
270
271 ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, OFFSET_TO_OFFBASE(offset), mLength);
272
273_match_stored:
274 /* match found */
275 ip += mLength;
276 anchor = ip;
277
278 if (ip <= ilimit) {
279 /* Complementary insertion */
280 /* done after iLimit test, as candidates could be > iend-8 */
281 { U32 const indexToInsert = curr+2;
282 hashLong[ZSTD_hashPtr(base+indexToInsert, hBitsL, 8)] = indexToInsert;
283 hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base);
284 hashSmall[ZSTD_hashPtr(base+indexToInsert, hBitsS, mls)] = indexToInsert;
285 hashSmall[ZSTD_hashPtr(ip-1, hBitsS, mls)] = (U32)(ip-1-base);
286 }
287
288 /* check immediate repcode */
289 while ( (ip <= ilimit)
290 && ( (offset_2>0)
291 & (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) {
292 /* store sequence */
293 size_t const rLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
294 U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff; /* swap offset_2 <=> offset_1 */
295 hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = (U32)(ip-base);
296 hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = (U32)(ip-base);
297 ZSTD_storeSeq(seqStore, 0, anchor, iend, REPCODE1_TO_OFFBASE, rLength);
298 ip += rLength;
299 anchor = ip;
300 continue; /* faster when present ... (?) */
301 }
302 }
303 }
304}
305
306
307FORCE_INLINE_TEMPLATE
308size_t ZSTD_compressBlock_doubleFast_dictMatchState_generic(
309 ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
310 void const* src, size_t srcSize,
311 U32 const mls /* template */)
312{
313 ZSTD_compressionParameters const* cParams = &ms->cParams;
314 U32* const hashLong = ms->hashTable;
315 const U32 hBitsL = cParams->hashLog;
316 U32* const hashSmall = ms->chainTable;
317 const U32 hBitsS = cParams->chainLog;
318 const BYTE* const base = ms->window.base;
319 const BYTE* const istart = (const BYTE*)src;
320 const BYTE* ip = istart;
321 const BYTE* anchor = istart;
322 const U32 endIndex = (U32)((size_t)(istart - base) + srcSize);
323 /* presumes that, if there is a dictionary, it must be using Attach mode */
324 const U32 prefixLowestIndex = ZSTD_getLowestPrefixIndex(ms, endIndex, cParams->windowLog);
325 const BYTE* const prefixLowest = base + prefixLowestIndex;
326 const BYTE* const iend = istart + srcSize;
327 const BYTE* const ilimit = iend - HASH_READ_SIZE;
328 U32 offset_1=rep[0], offset_2=rep[1];
329
330 const ZSTD_matchState_t* const dms = ms->dictMatchState;
331 const ZSTD_compressionParameters* const dictCParams = &dms->cParams;
332 const U32* const dictHashLong = dms->hashTable;
333 const U32* const dictHashSmall = dms->chainTable;
334 const U32 dictStartIndex = dms->window.dictLimit;
335 const BYTE* const dictBase = dms->window.base;
336 const BYTE* const dictStart = dictBase + dictStartIndex;
337 const BYTE* const dictEnd = dms->window.nextSrc;
338 const U32 dictIndexDelta = prefixLowestIndex - (U32)(dictEnd - dictBase);
339 const U32 dictHBitsL = dictCParams->hashLog + ZSTD_SHORT_CACHE_TAG_BITS;
340 const U32 dictHBitsS = dictCParams->chainLog + ZSTD_SHORT_CACHE_TAG_BITS;
341 const U32 dictAndPrefixLength = (U32)((ip - prefixLowest) + (dictEnd - dictStart));
342
343 DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_dictMatchState_generic");
344
345 /* if a dictionary is attached, it must be within window range */
346 assert(ms->window.dictLimit + (1U << cParams->windowLog) >= endIndex);
347
348 if (ms->prefetchCDictTables) {
349 size_t const hashTableBytes = (((size_t)1) << dictCParams->hashLog) * sizeof(U32);
350 size_t const chainTableBytes = (((size_t)1) << dictCParams->chainLog) * sizeof(U32);
351 PREFETCH_AREA(dictHashLong, hashTableBytes)
352 PREFETCH_AREA(dictHashSmall, chainTableBytes)
353 }
354
355 /* init */
356 ip += (dictAndPrefixLength == 0);
357
358 /* dictMatchState repCode checks don't currently handle repCode == 0
359 * disabling. */
360 assert(offset_1 <= dictAndPrefixLength);
361 assert(offset_2 <= dictAndPrefixLength);
362
363 /* Main Search Loop */
364 while (ip < ilimit) { /* < instead of <=, because repcode check at (ip+1) */
365 size_t mLength;
366 U32 offset;
367 size_t const h2 = ZSTD_hashPtr(ip, hBitsL, 8);
368 size_t const h = ZSTD_hashPtr(ip, hBitsS, mls);
369 size_t const dictHashAndTagL = ZSTD_hashPtr(ip, dictHBitsL, 8);
370 size_t const dictHashAndTagS = ZSTD_hashPtr(ip, dictHBitsS, mls);
371 U32 const dictMatchIndexAndTagL = dictHashLong[dictHashAndTagL >> ZSTD_SHORT_CACHE_TAG_BITS];
372 U32 const dictMatchIndexAndTagS = dictHashSmall[dictHashAndTagS >> ZSTD_SHORT_CACHE_TAG_BITS];
373 int const dictTagsMatchL = ZSTD_comparePackedTags(dictMatchIndexAndTagL, dictHashAndTagL);
374 int const dictTagsMatchS = ZSTD_comparePackedTags(dictMatchIndexAndTagS, dictHashAndTagS);
375 U32 const curr = (U32)(ip-base);
376 U32 const matchIndexL = hashLong[h2];
377 U32 matchIndexS = hashSmall[h];
378 const BYTE* matchLong = base + matchIndexL;
379 const BYTE* match = base + matchIndexS;
380 const U32 repIndex = curr + 1 - offset_1;
381 const BYTE* repMatch = (repIndex < prefixLowestIndex) ?
382 dictBase + (repIndex - dictIndexDelta) :
383 base + repIndex;
384 hashLong[h2] = hashSmall[h] = curr; /* update hash tables */
385
386 /* check repcode */
387 if (((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
388 && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
389 const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
390 mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
391 ip++;
392 ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, REPCODE1_TO_OFFBASE, mLength);
393 goto _match_stored;
394 }
395
396 if (matchIndexL > prefixLowestIndex) {
397 /* check prefix long match */
398 if (MEM_read64(matchLong) == MEM_read64(ip)) {
399 mLength = ZSTD_count(ip+8, matchLong+8, iend) + 8;
400 offset = (U32)(ip-matchLong);
401 while (((ip>anchor) & (matchLong>prefixLowest)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */
402 goto _match_found;
403 }
404 } else if (dictTagsMatchL) {
405 /* check dictMatchState long match */
406 U32 const dictMatchIndexL = dictMatchIndexAndTagL >> ZSTD_SHORT_CACHE_TAG_BITS;
407 const BYTE* dictMatchL = dictBase + dictMatchIndexL;
408 assert(dictMatchL < dictEnd);
409
410 if (dictMatchL > dictStart && MEM_read64(dictMatchL) == MEM_read64(ip)) {
411 mLength = ZSTD_count_2segments(ip+8, dictMatchL+8, iend, dictEnd, prefixLowest) + 8;
412 offset = (U32)(curr - dictMatchIndexL - dictIndexDelta);
413 while (((ip>anchor) & (dictMatchL>dictStart)) && (ip[-1] == dictMatchL[-1])) { ip--; dictMatchL--; mLength++; } /* catch up */
414 goto _match_found;
415 } }
416
417 if (matchIndexS > prefixLowestIndex) {
418 /* check prefix short match */
419 if (MEM_read32(match) == MEM_read32(ip)) {
420 goto _search_next_long;
421 }
422 } else if (dictTagsMatchS) {
423 /* check dictMatchState short match */
424 U32 const dictMatchIndexS = dictMatchIndexAndTagS >> ZSTD_SHORT_CACHE_TAG_BITS;
425 match = dictBase + dictMatchIndexS;
426 matchIndexS = dictMatchIndexS + dictIndexDelta;
427
428 if (match > dictStart && MEM_read32(match) == MEM_read32(ip)) {
429 goto _search_next_long;
430 } }
431
432 ip += ((ip-anchor) >> kSearchStrength) + 1;
433#if defined(__aarch64__)
434 PREFETCH_L1(ip+256);
435#endif
436 continue;
437
438_search_next_long:
439 { size_t const hl3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
440 size_t const dictHashAndTagL3 = ZSTD_hashPtr(ip+1, dictHBitsL, 8);
441 U32 const matchIndexL3 = hashLong[hl3];
442 U32 const dictMatchIndexAndTagL3 = dictHashLong[dictHashAndTagL3 >> ZSTD_SHORT_CACHE_TAG_BITS];
443 int const dictTagsMatchL3 = ZSTD_comparePackedTags(dictMatchIndexAndTagL3, dictHashAndTagL3);
444 const BYTE* matchL3 = base + matchIndexL3;
445 hashLong[hl3] = curr + 1;
446
447 /* check prefix long +1 match */
448 if (matchIndexL3 > prefixLowestIndex) {
449 if (MEM_read64(matchL3) == MEM_read64(ip+1)) {
450 mLength = ZSTD_count(ip+9, matchL3+8, iend) + 8;
451 ip++;
452 offset = (U32)(ip-matchL3);
453 while (((ip>anchor) & (matchL3>prefixLowest)) && (ip[-1] == matchL3[-1])) { ip--; matchL3--; mLength++; } /* catch up */
454 goto _match_found;
455 }
456 } else if (dictTagsMatchL3) {
457 /* check dict long +1 match */
458 U32 const dictMatchIndexL3 = dictMatchIndexAndTagL3 >> ZSTD_SHORT_CACHE_TAG_BITS;
459 const BYTE* dictMatchL3 = dictBase + dictMatchIndexL3;
460 assert(dictMatchL3 < dictEnd);
461 if (dictMatchL3 > dictStart && MEM_read64(dictMatchL3) == MEM_read64(ip+1)) {
462 mLength = ZSTD_count_2segments(ip+1+8, dictMatchL3+8, iend, dictEnd, prefixLowest) + 8;
463 ip++;
464 offset = (U32)(curr + 1 - dictMatchIndexL3 - dictIndexDelta);
465 while (((ip>anchor) & (dictMatchL3>dictStart)) && (ip[-1] == dictMatchL3[-1])) { ip--; dictMatchL3--; mLength++; } /* catch up */
466 goto _match_found;
467 } } }
468
469 /* if no long +1 match, explore the short match we found */
470 if (matchIndexS < prefixLowestIndex) {
471 mLength = ZSTD_count_2segments(ip+4, match+4, iend, dictEnd, prefixLowest) + 4;
472 offset = (U32)(curr - matchIndexS);
473 while (((ip>anchor) & (match>dictStart)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
474 } else {
475 mLength = ZSTD_count(ip+4, match+4, iend) + 4;
476 offset = (U32)(ip - match);
477 while (((ip>anchor) & (match>prefixLowest)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
478 }
479
480_match_found:
481 offset_2 = offset_1;
482 offset_1 = offset;
483
484 ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, OFFSET_TO_OFFBASE(offset), mLength);
485
486_match_stored:
487 /* match found */
488 ip += mLength;
489 anchor = ip;
490
491 if (ip <= ilimit) {
492 /* Complementary insertion */
493 /* done after iLimit test, as candidates could be > iend-8 */
494 { U32 const indexToInsert = curr+2;
495 hashLong[ZSTD_hashPtr(base+indexToInsert, hBitsL, 8)] = indexToInsert;
496 hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base);
497 hashSmall[ZSTD_hashPtr(base+indexToInsert, hBitsS, mls)] = indexToInsert;
498 hashSmall[ZSTD_hashPtr(ip-1, hBitsS, mls)] = (U32)(ip-1-base);
499 }
500
501 /* check immediate repcode */
502 while (ip <= ilimit) {
503 U32 const current2 = (U32)(ip-base);
504 U32 const repIndex2 = current2 - offset_2;
505 const BYTE* repMatch2 = repIndex2 < prefixLowestIndex ?
506 dictBase + repIndex2 - dictIndexDelta :
507 base + repIndex2;
508 if ( ((U32)((prefixLowestIndex-1) - (U32)repIndex2) >= 3 /* intentional overflow */)
509 && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
510 const BYTE* const repEnd2 = repIndex2 < prefixLowestIndex ? dictEnd : iend;
511 size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixLowest) + 4;
512 U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset; /* swap offset_2 <=> offset_1 */
513 ZSTD_storeSeq(seqStore, 0, anchor, iend, REPCODE1_TO_OFFBASE, repLength2);
514 hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = current2;
515 hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = current2;
516 ip += repLength2;
517 anchor = ip;
518 continue;
519 }
520 break;
521 }
522 }
523 } /* while (ip < ilimit) */
524
525 /* save reps for next block */
526 rep[0] = offset_1;
527 rep[1] = offset_2;
528
529 /* Return the last literals size */
530 return (size_t)(iend - anchor);
531}
532
533#define ZSTD_GEN_DFAST_FN(dictMode, mls) \
534 static size_t ZSTD_compressBlock_doubleFast_##dictMode##_##mls( \
535 ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], \
536 void const* src, size_t srcSize) \
537 { \
538 return ZSTD_compressBlock_doubleFast_##dictMode##_generic(ms, seqStore, rep, src, srcSize, mls); \
539 }
540
541ZSTD_GEN_DFAST_FN(noDict, 4)
542ZSTD_GEN_DFAST_FN(noDict, 5)
543ZSTD_GEN_DFAST_FN(noDict, 6)
544ZSTD_GEN_DFAST_FN(noDict, 7)
545
546ZSTD_GEN_DFAST_FN(dictMatchState, 4)
547ZSTD_GEN_DFAST_FN(dictMatchState, 5)
548ZSTD_GEN_DFAST_FN(dictMatchState, 6)
549ZSTD_GEN_DFAST_FN(dictMatchState, 7)
550
551
552size_t ZSTD_compressBlock_doubleFast(
553 ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
554 void const* src, size_t srcSize)
555{
556 const U32 mls = ms->cParams.minMatch;
557 switch(mls)
558 {
559 default: /* includes case 3 */
560 case 4 :
561 return ZSTD_compressBlock_doubleFast_noDict_4(ms, seqStore, rep, src, srcSize);
562 case 5 :
563 return ZSTD_compressBlock_doubleFast_noDict_5(ms, seqStore, rep, src, srcSize);
564 case 6 :
565 return ZSTD_compressBlock_doubleFast_noDict_6(ms, seqStore, rep, src, srcSize);
566 case 7 :
567 return ZSTD_compressBlock_doubleFast_noDict_7(ms, seqStore, rep, src, srcSize);
568 }
569}
570
571
572size_t ZSTD_compressBlock_doubleFast_dictMatchState(
573 ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
574 void const* src, size_t srcSize)
575{
576 const U32 mls = ms->cParams.minMatch;
577 switch(mls)
578 {
579 default: /* includes case 3 */
580 case 4 :
581 return ZSTD_compressBlock_doubleFast_dictMatchState_4(ms, seqStore, rep, src, srcSize);
582 case 5 :
583 return ZSTD_compressBlock_doubleFast_dictMatchState_5(ms, seqStore, rep, src, srcSize);
584 case 6 :
585 return ZSTD_compressBlock_doubleFast_dictMatchState_6(ms, seqStore, rep, src, srcSize);
586 case 7 :
587 return ZSTD_compressBlock_doubleFast_dictMatchState_7(ms, seqStore, rep, src, srcSize);
588 }
589}
590
591
592static size_t ZSTD_compressBlock_doubleFast_extDict_generic(
593 ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
594 void const* src, size_t srcSize,
595 U32 const mls /* template */)
596{
597 ZSTD_compressionParameters const* cParams = &ms->cParams;
598 U32* const hashLong = ms->hashTable;
599 U32 const hBitsL = cParams->hashLog;
600 U32* const hashSmall = ms->chainTable;
601 U32 const hBitsS = cParams->chainLog;
602 const BYTE* const istart = (const BYTE*)src;
603 const BYTE* ip = istart;
604 const BYTE* anchor = istart;
605 const BYTE* const iend = istart + srcSize;
606 const BYTE* const ilimit = iend - 8;
607 const BYTE* const base = ms->window.base;
608 const U32 endIndex = (U32)((size_t)(istart - base) + srcSize);
609 const U32 lowLimit = ZSTD_getLowestMatchIndex(ms, endIndex, cParams->windowLog);
610 const U32 dictStartIndex = lowLimit;
611 const U32 dictLimit = ms->window.dictLimit;
612 const U32 prefixStartIndex = (dictLimit > lowLimit) ? dictLimit : lowLimit;
613 const BYTE* const prefixStart = base + prefixStartIndex;
614 const BYTE* const dictBase = ms->window.dictBase;
615 const BYTE* const dictStart = dictBase + dictStartIndex;
616 const BYTE* const dictEnd = dictBase + prefixStartIndex;
617 U32 offset_1=rep[0], offset_2=rep[1];
618
619 DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_extDict_generic (srcSize=%zu)", srcSize);
620
621 /* if extDict is invalidated due to maxDistance, switch to "regular" variant */
622 if (prefixStartIndex == dictStartIndex)
623 return ZSTD_compressBlock_doubleFast(ms, seqStore, rep, src, srcSize);
624
625 /* Search Loop */
626 while (ip < ilimit) { /* < instead of <=, because (ip+1) */
627 const size_t hSmall = ZSTD_hashPtr(ip, hBitsS, mls);
628 const U32 matchIndex = hashSmall[hSmall];
629 const BYTE* const matchBase = matchIndex < prefixStartIndex ? dictBase : base;
630 const BYTE* match = matchBase + matchIndex;
631
632 const size_t hLong = ZSTD_hashPtr(ip, hBitsL, 8);
633 const U32 matchLongIndex = hashLong[hLong];
634 const BYTE* const matchLongBase = matchLongIndex < prefixStartIndex ? dictBase : base;
635 const BYTE* matchLong = matchLongBase + matchLongIndex;
636
637 const U32 curr = (U32)(ip-base);
638 const U32 repIndex = curr + 1 - offset_1; /* offset_1 expected <= curr +1 */
639 const BYTE* const repBase = repIndex < prefixStartIndex ? dictBase : base;
640 const BYTE* const repMatch = repBase + repIndex;
641 size_t mLength;
642 hashSmall[hSmall] = hashLong[hLong] = curr; /* update hash table */
643
644 if ((((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow : ensure repIndex doesn't overlap dict + prefix */
645 & (offset_1 <= curr+1 - dictStartIndex)) /* note: we are searching at curr+1 */
646 && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
647 const BYTE* repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
648 mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixStart) + 4;
649 ip++;
650 ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, REPCODE1_TO_OFFBASE, mLength);
651 } else {
652 if ((matchLongIndex > dictStartIndex) && (MEM_read64(matchLong) == MEM_read64(ip))) {
653 const BYTE* const matchEnd = matchLongIndex < prefixStartIndex ? dictEnd : iend;
654 const BYTE* const lowMatchPtr = matchLongIndex < prefixStartIndex ? dictStart : prefixStart;
655 U32 offset;
656 mLength = ZSTD_count_2segments(ip+8, matchLong+8, iend, matchEnd, prefixStart) + 8;
657 offset = curr - matchLongIndex;
658 while (((ip>anchor) & (matchLong>lowMatchPtr)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */
659 offset_2 = offset_1;
660 offset_1 = offset;
661 ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, OFFSET_TO_OFFBASE(offset), mLength);
662
663 } else if ((matchIndex > dictStartIndex) && (MEM_read32(match) == MEM_read32(ip))) {
664 size_t const h3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
665 U32 const matchIndex3 = hashLong[h3];
666 const BYTE* const match3Base = matchIndex3 < prefixStartIndex ? dictBase : base;
667 const BYTE* match3 = match3Base + matchIndex3;
668 U32 offset;
669 hashLong[h3] = curr + 1;
670 if ( (matchIndex3 > dictStartIndex) && (MEM_read64(match3) == MEM_read64(ip+1)) ) {
671 const BYTE* const matchEnd = matchIndex3 < prefixStartIndex ? dictEnd : iend;
672 const BYTE* const lowMatchPtr = matchIndex3 < prefixStartIndex ? dictStart : prefixStart;
673 mLength = ZSTD_count_2segments(ip+9, match3+8, iend, matchEnd, prefixStart) + 8;
674 ip++;
675 offset = curr+1 - matchIndex3;
676 while (((ip>anchor) & (match3>lowMatchPtr)) && (ip[-1] == match3[-1])) { ip--; match3--; mLength++; } /* catch up */
677 } else {
678 const BYTE* const matchEnd = matchIndex < prefixStartIndex ? dictEnd : iend;
679 const BYTE* const lowMatchPtr = matchIndex < prefixStartIndex ? dictStart : prefixStart;
680 mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, prefixStart) + 4;
681 offset = curr - matchIndex;
682 while (((ip>anchor) & (match>lowMatchPtr)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
683 }
684 offset_2 = offset_1;
685 offset_1 = offset;
686 ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, OFFSET_TO_OFFBASE(offset), mLength);
687
688 } else {
689 ip += ((ip-anchor) >> kSearchStrength) + 1;
690 continue;
691 } }
692
693 /* move to next sequence start */
694 ip += mLength;
695 anchor = ip;
696
697 if (ip <= ilimit) {
698 /* Complementary insertion */
699 /* done after iLimit test, as candidates could be > iend-8 */
700 { U32 const indexToInsert = curr+2;
701 hashLong[ZSTD_hashPtr(base+indexToInsert, hBitsL, 8)] = indexToInsert;
702 hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base);
703 hashSmall[ZSTD_hashPtr(base+indexToInsert, hBitsS, mls)] = indexToInsert;
704 hashSmall[ZSTD_hashPtr(ip-1, hBitsS, mls)] = (U32)(ip-1-base);
705 }
706
707 /* check immediate repcode */
708 while (ip <= ilimit) {
709 U32 const current2 = (U32)(ip-base);
710 U32 const repIndex2 = current2 - offset_2;
711 const BYTE* repMatch2 = repIndex2 < prefixStartIndex ? dictBase + repIndex2 : base + repIndex2;
712 if ( (((U32)((prefixStartIndex-1) - repIndex2) >= 3) /* intentional overflow : ensure repIndex2 doesn't overlap dict + prefix */
713 & (offset_2 <= current2 - dictStartIndex))
714 && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
715 const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend;
716 size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixStart) + 4;
717 U32 const tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset; /* swap offset_2 <=> offset_1 */
718 ZSTD_storeSeq(seqStore, 0, anchor, iend, REPCODE1_TO_OFFBASE, repLength2);
719 hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = current2;
720 hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = current2;
721 ip += repLength2;
722 anchor = ip;
723 continue;
724 }
725 break;
726 } } }
727
728 /* save reps for next block */
729 rep[0] = offset_1;
730 rep[1] = offset_2;
731
732 /* Return the last literals size */
733 return (size_t)(iend - anchor);
734}
735
736ZSTD_GEN_DFAST_FN(extDict, 4)
737ZSTD_GEN_DFAST_FN(extDict, 5)
738ZSTD_GEN_DFAST_FN(extDict, 6)
739ZSTD_GEN_DFAST_FN(extDict, 7)
740
741size_t ZSTD_compressBlock_doubleFast_extDict(
742 ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
743 void const* src, size_t srcSize)
744{
745 U32 const mls = ms->cParams.minMatch;
746 switch(mls)
747 {
748 default: /* includes case 3 */
749 case 4 :
750 return ZSTD_compressBlock_doubleFast_extDict_4(ms, seqStore, rep, src, srcSize);
751 case 5 :
752 return ZSTD_compressBlock_doubleFast_extDict_5(ms, seqStore, rep, src, srcSize);
753 case 6 :
754 return ZSTD_compressBlock_doubleFast_extDict_6(ms, seqStore, rep, src, srcSize);
755 case 7 :
756 return ZSTD_compressBlock_doubleFast_extDict_7(ms, seqStore, rep, src, srcSize);
757 }
758}
759