1/** 2 * Copyright (c) 2016-present, Przemyslaw Skibinski, Yann Collet, Facebook, Inc. 3 * All rights reserved. 4 * 5 * This source code is licensed under the BSD-style license found in the 6 * LICENSE file in the root directory of https://github.com/facebook/zstd. 7 * An additional grant of patent rights can be found in the PATENTS file in the 8 * same directory. 9 * 10 * This program is free software; you can redistribute it and/or modify it under 11 * the terms of the GNU General Public License version 2 as published by the 12 * Free Software Foundation. This program is dual-licensed; you may select 13 * either version 2 of the GNU General Public License ("GPL") or BSD license 14 * ("BSD"). 15 */ 16 17/* Note : this file is intended to be included within zstd_compress.c */ 18 19#ifndef ZSTD_OPT_H_91842398743 20#define ZSTD_OPT_H_91842398743 21 22#define ZSTD_LITFREQ_ADD 2 23#define ZSTD_FREQ_DIV 4 24#define ZSTD_MAX_PRICE (1 << 30) 25 26/*-************************************* 27* Price functions for optimal parser 28***************************************/ 29FORCE_INLINE void ZSTD_setLog2Prices(seqStore_t *ssPtr) 30{ 31 ssPtr->log2matchLengthSum = ZSTD_highbit32(ssPtr->matchLengthSum + 1); 32 ssPtr->log2litLengthSum = ZSTD_highbit32(ssPtr->litLengthSum + 1); 33 ssPtr->log2litSum = ZSTD_highbit32(ssPtr->litSum + 1); 34 ssPtr->log2offCodeSum = ZSTD_highbit32(ssPtr->offCodeSum + 1); 35 ssPtr->factor = 1 + ((ssPtr->litSum >> 5) / ssPtr->litLengthSum) + ((ssPtr->litSum << 1) / (ssPtr->litSum + ssPtr->matchSum)); 36} 37 38ZSTD_STATIC void ZSTD_rescaleFreqs(seqStore_t *ssPtr, const BYTE *src, size_t srcSize) 39{ 40 unsigned u; 41 42 ssPtr->cachedLiterals = NULL; 43 ssPtr->cachedPrice = ssPtr->cachedLitLength = 0; 44 ssPtr->staticPrices = 0; 45 46 if (ssPtr->litLengthSum == 0) { 47 if (srcSize <= 1024) 48 ssPtr->staticPrices = 1; 49 50 for (u = 0; u <= MaxLit; u++) 51 ssPtr->litFreq[u] = 0; 52 for (u = 0; u < srcSize; u++) 53 ssPtr->litFreq[src[u]]++; 54 55 ssPtr->litSum = 0; 56 ssPtr->litLengthSum = MaxLL + 1; 57 ssPtr->matchLengthSum = MaxML + 1; 58 ssPtr->offCodeSum = (MaxOff + 1); 59 ssPtr->matchSum = (ZSTD_LITFREQ_ADD << Litbits); 60 61 for (u = 0; u <= MaxLit; u++) { 62 ssPtr->litFreq[u] = 1 + (ssPtr->litFreq[u] >> ZSTD_FREQ_DIV); 63 ssPtr->litSum += ssPtr->litFreq[u]; 64 } 65 for (u = 0; u <= MaxLL; u++) 66 ssPtr->litLengthFreq[u] = 1; 67 for (u = 0; u <= MaxML; u++) 68 ssPtr->matchLengthFreq[u] = 1; 69 for (u = 0; u <= MaxOff; u++) 70 ssPtr->offCodeFreq[u] = 1; 71 } else { 72 ssPtr->matchLengthSum = 0; 73 ssPtr->litLengthSum = 0; 74 ssPtr->offCodeSum = 0; 75 ssPtr->matchSum = 0; 76 ssPtr->litSum = 0; 77 78 for (u = 0; u <= MaxLit; u++) { 79 ssPtr->litFreq[u] = 1 + (ssPtr->litFreq[u] >> (ZSTD_FREQ_DIV + 1)); 80 ssPtr->litSum += ssPtr->litFreq[u]; 81 } 82 for (u = 0; u <= MaxLL; u++) { 83 ssPtr->litLengthFreq[u] = 1 + (ssPtr->litLengthFreq[u] >> (ZSTD_FREQ_DIV + 1)); 84 ssPtr->litLengthSum += ssPtr->litLengthFreq[u]; 85 } 86 for (u = 0; u <= MaxML; u++) { 87 ssPtr->matchLengthFreq[u] = 1 + (ssPtr->matchLengthFreq[u] >> ZSTD_FREQ_DIV); 88 ssPtr->matchLengthSum += ssPtr->matchLengthFreq[u]; 89 ssPtr->matchSum += ssPtr->matchLengthFreq[u] * (u + 3); 90 } 91 ssPtr->matchSum *= ZSTD_LITFREQ_ADD; 92 for (u = 0; u <= MaxOff; u++) { 93 ssPtr->offCodeFreq[u] = 1 + (ssPtr->offCodeFreq[u] >> ZSTD_FREQ_DIV); 94 ssPtr->offCodeSum += ssPtr->offCodeFreq[u]; 95 } 96 } 97 98 ZSTD_setLog2Prices(ssPtr); 99} 100 101FORCE_INLINE U32 ZSTD_getLiteralPrice(seqStore_t *ssPtr, U32 litLength, const BYTE *literals) 102{ 103 U32 price, u; 104 105 if (ssPtr->staticPrices) 106 return ZSTD_highbit32((U32)litLength + 1) + (litLength * 6); 107 108 if (litLength == 0) 109 return ssPtr->log2litLengthSum - ZSTD_highbit32(ssPtr->litLengthFreq[0] + 1); 110 111 /* literals */ 112 if (ssPtr->cachedLiterals == literals) { 113 U32 const additional = litLength - ssPtr->cachedLitLength; 114 const BYTE *literals2 = ssPtr->cachedLiterals + ssPtr->cachedLitLength; 115 price = ssPtr->cachedPrice + additional * ssPtr->log2litSum; 116 for (u = 0; u < additional; u++) 117 price -= ZSTD_highbit32(ssPtr->litFreq[literals2[u]] + 1); 118 ssPtr->cachedPrice = price; 119 ssPtr->cachedLitLength = litLength; 120 } else { 121 price = litLength * ssPtr->log2litSum; 122 for (u = 0; u < litLength; u++) 123 price -= ZSTD_highbit32(ssPtr->litFreq[literals[u]] + 1); 124 125 if (litLength >= 12) { 126 ssPtr->cachedLiterals = literals; 127 ssPtr->cachedPrice = price; 128 ssPtr->cachedLitLength = litLength; 129 } 130 } 131 132 /* literal Length */ 133 { 134 const BYTE LL_deltaCode = 19; 135 const BYTE llCode = (litLength > 63) ? (BYTE)ZSTD_highbit32(litLength) + LL_deltaCode : LL_Code[litLength]; 136 price += LL_bits[llCode] + ssPtr->log2litLengthSum - ZSTD_highbit32(ssPtr->litLengthFreq[llCode] + 1); 137 } 138 139 return price; 140} 141 142FORCE_INLINE U32 ZSTD_getPrice(seqStore_t *seqStorePtr, U32 litLength, const BYTE *literals, U32 offset, U32 matchLength, const int ultra) 143{ 144 /* offset */ 145 U32 price; 146 BYTE const offCode = (BYTE)ZSTD_highbit32(offset + 1); 147 148 if (seqStorePtr->staticPrices) 149 return ZSTD_getLiteralPrice(seqStorePtr, litLength, literals) + ZSTD_highbit32((U32)matchLength + 1) + 16 + offCode; 150 151 price = offCode + seqStorePtr->log2offCodeSum - ZSTD_highbit32(seqStorePtr->offCodeFreq[offCode] + 1); 152 if (!ultra && offCode >= 20) 153 price += (offCode - 19) * 2; 154 155 /* match Length */ 156 { 157 const BYTE ML_deltaCode = 36; 158 const BYTE mlCode = (matchLength > 127) ? (BYTE)ZSTD_highbit32(matchLength) + ML_deltaCode : ML_Code[matchLength]; 159 price += ML_bits[mlCode] + seqStorePtr->log2matchLengthSum - ZSTD_highbit32(seqStorePtr->matchLengthFreq[mlCode] + 1); 160 } 161 162 return price + ZSTD_getLiteralPrice(seqStorePtr, litLength, literals) + seqStorePtr->factor; 163} 164 165ZSTD_STATIC void ZSTD_updatePrice(seqStore_t *seqStorePtr, U32 litLength, const BYTE *literals, U32 offset, U32 matchLength) 166{ 167 U32 u; 168 169 /* literals */ 170 seqStorePtr->litSum += litLength * ZSTD_LITFREQ_ADD; 171 for (u = 0; u < litLength; u++) 172 seqStorePtr->litFreq[literals[u]] += ZSTD_LITFREQ_ADD; 173 174 /* literal Length */ 175 { 176 const BYTE LL_deltaCode = 19; 177 const BYTE llCode = (litLength > 63) ? (BYTE)ZSTD_highbit32(litLength) + LL_deltaCode : LL_Code[litLength]; 178 seqStorePtr->litLengthFreq[llCode]++; 179 seqStorePtr->litLengthSum++; 180 } 181 182 /* match offset */ 183 { 184 BYTE const offCode = (BYTE)ZSTD_highbit32(offset + 1); 185 seqStorePtr->offCodeSum++; 186 seqStorePtr->offCodeFreq[offCode]++; 187 } 188 189 /* match Length */ 190 { 191 const BYTE ML_deltaCode = 36; 192 const BYTE mlCode = (matchLength > 127) ? (BYTE)ZSTD_highbit32(matchLength) + ML_deltaCode : ML_Code[matchLength]; 193 seqStorePtr->matchLengthFreq[mlCode]++; 194 seqStorePtr->matchLengthSum++; 195 } 196 197 ZSTD_setLog2Prices(seqStorePtr); 198} 199 200#define SET_PRICE(pos, mlen_, offset_, litlen_, price_) \ 201 { \ 202 while (last_pos < pos) { \ 203 opt[last_pos + 1].price = ZSTD_MAX_PRICE; \ 204 last_pos++; \ 205 } \ 206 opt[pos].mlen = mlen_; \ 207 opt[pos].off = offset_; \ 208 opt[pos].litlen = litlen_; \ 209 opt[pos].price = price_; \ 210 } 211 212/* Update hashTable3 up to ip (excluded) 213 Assumption : always within prefix (i.e. not within extDict) */ 214FORCE_INLINE 215U32 ZSTD_insertAndFindFirstIndexHash3(ZSTD_CCtx *zc, const BYTE *ip) 216{ 217 U32 *const hashTable3 = zc->hashTable3; 218 U32 const hashLog3 = zc->hashLog3; 219 const BYTE *const base = zc->base; 220 U32 idx = zc->nextToUpdate3; 221 const U32 target = zc->nextToUpdate3 = (U32)(ip - base); 222 const size_t hash3 = ZSTD_hash3Ptr(ip, hashLog3); 223 224 while (idx < target) { 225 hashTable3[ZSTD_hash3Ptr(base + idx, hashLog3)] = idx; 226 idx++; 227 } 228 229 return hashTable3[hash3]; 230} 231 232/*-************************************* 233* Binary Tree search 234***************************************/ 235static U32 ZSTD_insertBtAndGetAllMatches(ZSTD_CCtx *zc, const BYTE *const ip, const BYTE *const iLimit, U32 nbCompares, const U32 mls, U32 extDict, 236 ZSTD_match_t *matches, const U32 minMatchLen) 237{ 238 const BYTE *const base = zc->base; 239 const U32 curr = (U32)(ip - base); 240 const U32 hashLog = zc->params.cParams.hashLog; 241 const size_t h = ZSTD_hashPtr(ip, hashLog, mls); 242 U32 *const hashTable = zc->hashTable; 243 U32 matchIndex = hashTable[h]; 244 U32 *const bt = zc->chainTable; 245 const U32 btLog = zc->params.cParams.chainLog - 1; 246 const U32 btMask = (1U << btLog) - 1; 247 size_t commonLengthSmaller = 0, commonLengthLarger = 0; 248 const BYTE *const dictBase = zc->dictBase; 249 const U32 dictLimit = zc->dictLimit; 250 const BYTE *const dictEnd = dictBase + dictLimit; 251 const BYTE *const prefixStart = base + dictLimit; 252 const U32 btLow = btMask >= curr ? 0 : curr - btMask; 253 const U32 windowLow = zc->lowLimit; 254 U32 *smallerPtr = bt + 2 * (curr & btMask); 255 U32 *largerPtr = bt + 2 * (curr & btMask) + 1; 256 U32 matchEndIdx = curr + 8; 257 U32 dummy32; /* to be nullified at the end */ 258 U32 mnum = 0; 259 260 const U32 minMatch = (mls == 3) ? 3 : 4; 261 size_t bestLength = minMatchLen - 1; 262 263 if (minMatch == 3) { /* HC3 match finder */ 264 U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3(zc, ip); 265 if (matchIndex3 > windowLow && (curr - matchIndex3 < (1 << 18))) { 266 const BYTE *match; 267 size_t currMl = 0; 268 if ((!extDict) || matchIndex3 >= dictLimit) { 269 match = base + matchIndex3; 270 if (match[bestLength] == ip[bestLength]) 271 currMl = ZSTD_count(ip, match, iLimit); 272 } else { 273 match = dictBase + matchIndex3; 274 if (ZSTD_readMINMATCH(match, MINMATCH) == 275 ZSTD_readMINMATCH(ip, MINMATCH)) /* assumption : matchIndex3 <= dictLimit-4 (by table construction) */ 276 currMl = ZSTD_count_2segments(ip + MINMATCH, match + MINMATCH, iLimit, dictEnd, prefixStart) + MINMATCH; 277 } 278 279 /* save best solution */ 280 if (currMl > bestLength) { 281 bestLength = currMl; 282 matches[mnum].off = ZSTD_REP_MOVE_OPT + curr - matchIndex3; 283 matches[mnum].len = (U32)currMl; 284 mnum++; 285 if (currMl > ZSTD_OPT_NUM) 286 goto update; 287 if (ip + currMl == iLimit) 288 goto update; /* best possible, and avoid read overflow*/ 289 } 290 } 291 } 292 293 hashTable[h] = curr; /* Update Hash Table */ 294 295 while (nbCompares-- && (matchIndex > windowLow)) { 296 U32 *nextPtr = bt + 2 * (matchIndex & btMask); 297 size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */ 298 const BYTE *match; 299 300 if ((!extDict) || (matchIndex + matchLength >= dictLimit)) { 301 match = base + matchIndex; 302 if (match[matchLength] == ip[matchLength]) { 303 matchLength += ZSTD_count(ip + matchLength + 1, match + matchLength + 1, iLimit) + 1; 304 } 305 } else { 306 match = dictBase + matchIndex; 307 matchLength += ZSTD_count_2segments(ip + matchLength, match + matchLength, iLimit, dictEnd, prefixStart); 308 if (matchIndex + matchLength >= dictLimit) 309 match = base + matchIndex; /* to prepare for next usage of match[matchLength] */ 310 } 311 312 if (matchLength > bestLength) { 313 if (matchLength > matchEndIdx - matchIndex) 314 matchEndIdx = matchIndex + (U32)matchLength; 315 bestLength = matchLength; 316 matches[mnum].off = ZSTD_REP_MOVE_OPT + curr - matchIndex; 317 matches[mnum].len = (U32)matchLength; 318 mnum++; 319 if (matchLength > ZSTD_OPT_NUM) 320 break; 321 if (ip + matchLength == iLimit) /* equal : no way to know if inf or sup */ 322 break; /* drop, to guarantee consistency (miss a little bit of compression) */ 323 } 324 325 if (match[matchLength] < ip[matchLength]) { 326 /* match is smaller than curr */ 327 *smallerPtr = matchIndex; /* update smaller idx */ 328 commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */ 329 if (matchIndex <= btLow) { 330 smallerPtr = &dummy32; 331 break; 332 } /* beyond tree size, stop the search */ 333 smallerPtr = nextPtr + 1; /* new "smaller" => larger of match */ 334 matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to curr) */ 335 } else { 336 /* match is larger than curr */ 337 *largerPtr = matchIndex; 338 commonLengthLarger = matchLength; 339 if (matchIndex <= btLow) { 340 largerPtr = &dummy32; 341 break; 342 } /* beyond tree size, stop the search */ 343 largerPtr = nextPtr; 344 matchIndex = nextPtr[0]; 345 } 346 } 347 348 *smallerPtr = *largerPtr = 0; 349 350update: 351 zc->nextToUpdate = (matchEndIdx > curr + 8) ? matchEndIdx - 8 : curr + 1; 352 return mnum; 353} 354 355/** Tree updater, providing best match */ 356static U32 ZSTD_BtGetAllMatches(ZSTD_CCtx *zc, const BYTE *const ip, const BYTE *const iLimit, const U32 maxNbAttempts, const U32 mls, ZSTD_match_t *matches, 357 const U32 minMatchLen) 358{ 359 if (ip < zc->base + zc->nextToUpdate) 360 return 0; /* skipped area */ 361 ZSTD_updateTree(zc, ip, iLimit, maxNbAttempts, mls); 362 return ZSTD_insertBtAndGetAllMatches(zc, ip, iLimit, maxNbAttempts, mls, 0, matches, minMatchLen); 363} 364 365static U32 ZSTD_BtGetAllMatches_selectMLS(ZSTD_CCtx *zc, /* Index table will be updated */ 366 const BYTE *ip, const BYTE *const iHighLimit, const U32 maxNbAttempts, const U32 matchLengthSearch, 367 ZSTD_match_t *matches, const U32 minMatchLen) 368{ 369 switch (matchLengthSearch) { 370 case 3: return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 3, matches, minMatchLen); 371 default: 372 case 4: return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 4, matches, minMatchLen); 373 case 5: return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 5, matches, minMatchLen); 374 case 7: 375 case 6: return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 6, matches, minMatchLen); 376 } 377} 378 379/** Tree updater, providing best match */ 380static U32 ZSTD_BtGetAllMatches_extDict(ZSTD_CCtx *zc, const BYTE *const ip, const BYTE *const iLimit, const U32 maxNbAttempts, const U32 mls, 381 ZSTD_match_t *matches, const U32 minMatchLen) 382{ 383 if (ip < zc->base + zc->nextToUpdate) 384 return 0; /* skipped area */ 385 ZSTD_updateTree_extDict(zc, ip, iLimit, maxNbAttempts, mls); 386 return ZSTD_insertBtAndGetAllMatches(zc, ip, iLimit, maxNbAttempts, mls, 1, matches, minMatchLen); 387} 388 389static U32 ZSTD_BtGetAllMatches_selectMLS_extDict(ZSTD_CCtx *zc, /* Index table will be updated */ 390 const BYTE *ip, const BYTE *const iHighLimit, const U32 maxNbAttempts, const U32 matchLengthSearch, 391 ZSTD_match_t *matches, const U32 minMatchLen) 392{ 393 switch (matchLengthSearch) { 394 case 3: return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 3, matches, minMatchLen); 395 default: 396 case 4: return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 4, matches, minMatchLen); 397 case 5: return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 5, matches, minMatchLen); 398 case 7: 399 case 6: return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 6, matches, minMatchLen); 400 } 401} 402 403/*-******************************* 404* Optimal parser 405*********************************/ 406FORCE_INLINE 407void ZSTD_compressBlock_opt_generic(ZSTD_CCtx *ctx, const void *src, size_t srcSize, const int ultra) 408{ 409 seqStore_t *seqStorePtr = &(ctx->seqStore); 410 const BYTE *const istart = (const BYTE *)src; 411 const BYTE *ip = istart; 412 const BYTE *anchor = istart; 413 const BYTE *const iend = istart + srcSize; 414 const BYTE *const ilimit = iend - 8; 415 const BYTE *const base = ctx->base; 416 const BYTE *const prefixStart = base + ctx->dictLimit; 417 418 const U32 maxSearches = 1U << ctx->params.cParams.searchLog; 419 const U32 sufficient_len = ctx->params.cParams.targetLength; 420 const U32 mls = ctx->params.cParams.searchLength; 421 const U32 minMatch = (ctx->params.cParams.searchLength == 3) ? 3 : 4; 422 423 ZSTD_optimal_t *opt = seqStorePtr->priceTable; 424 ZSTD_match_t *matches = seqStorePtr->matchTable; 425 const BYTE *inr; 426 U32 offset, rep[ZSTD_REP_NUM]; 427 428 /* init */ 429 ctx->nextToUpdate3 = ctx->nextToUpdate; 430 ZSTD_rescaleFreqs(seqStorePtr, (const BYTE *)src, srcSize); 431 ip += (ip == prefixStart); 432 { 433 U32 i; 434 for (i = 0; i < ZSTD_REP_NUM; i++) 435 rep[i] = ctx->rep[i]; 436 } 437 438 /* Match Loop */ 439 while (ip < ilimit) { 440 U32 cur, match_num, last_pos, litlen, price; 441 U32 u, mlen, best_mlen, best_off, litLength; 442 memset(opt, 0, sizeof(ZSTD_optimal_t)); 443 last_pos = 0; 444 litlen = (U32)(ip - anchor); 445 446 /* check repCode */ 447 { 448 U32 i, last_i = ZSTD_REP_CHECK + (ip == anchor); 449 for (i = (ip == anchor); i < last_i; i++) { 450 const S32 repCur = (i == ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : rep[i]; 451 if ((repCur > 0) && (repCur < (S32)(ip - prefixStart)) && 452 (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(ip - repCur, minMatch))) { 453 mlen = (U32)ZSTD_count(ip + minMatch, ip + minMatch - repCur, iend) + minMatch; 454 if (mlen > sufficient_len || mlen >= ZSTD_OPT_NUM) { 455 best_mlen = mlen; 456 best_off = i; 457 cur = 0; 458 last_pos = 1; 459 goto _storeSequence; 460 } 461 best_off = i - (ip == anchor); 462 do { 463 price = ZSTD_getPrice(seqStorePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra); 464 if (mlen > last_pos || price < opt[mlen].price) 465 SET_PRICE(mlen, mlen, i, litlen, price); /* note : macro modifies last_pos */ 466 mlen--; 467 } while (mlen >= minMatch); 468 } 469 } 470 } 471 472 match_num = ZSTD_BtGetAllMatches_selectMLS(ctx, ip, iend, maxSearches, mls, matches, minMatch); 473 474 if (!last_pos && !match_num) { 475 ip++; 476 continue; 477 } 478 479 if (match_num && (matches[match_num - 1].len > sufficient_len || matches[match_num - 1].len >= ZSTD_OPT_NUM)) { 480 best_mlen = matches[match_num - 1].len; 481 best_off = matches[match_num - 1].off; 482 cur = 0; 483 last_pos = 1; 484 goto _storeSequence; 485 } 486 487 /* set prices using matches at position = 0 */ 488 best_mlen = (last_pos) ? last_pos : minMatch; 489 for (u = 0; u < match_num; u++) { 490 mlen = (u > 0) ? matches[u - 1].len + 1 : best_mlen; 491 best_mlen = matches[u].len; 492 while (mlen <= best_mlen) { 493 price = ZSTD_getPrice(seqStorePtr, litlen, anchor, matches[u].off - 1, mlen - MINMATCH, ultra); 494 if (mlen > last_pos || price < opt[mlen].price) 495 SET_PRICE(mlen, mlen, matches[u].off, litlen, price); /* note : macro modifies last_pos */ 496 mlen++; 497 } 498 } 499 500 if (last_pos < minMatch) { 501 ip++; 502 continue; 503 } 504 505 /* initialize opt[0] */ 506 { 507 U32 i; 508 for (i = 0; i < ZSTD_REP_NUM; i++) 509 opt[0].rep[i] = rep[i]; 510 } 511 opt[0].mlen = 1; 512 opt[0].litlen = litlen; 513 514 /* check further positions */ 515 for (cur = 1; cur <= last_pos; cur++) { 516 inr = ip + cur; 517 518 if (opt[cur - 1].mlen == 1) { 519 litlen = opt[cur - 1].litlen + 1; 520 if (cur > litlen) { 521 price = opt[cur - litlen].price + ZSTD_getLiteralPrice(seqStorePtr, litlen, inr - litlen); 522 } else 523 price = ZSTD_getLiteralPrice(seqStorePtr, litlen, anchor); 524 } else { 525 litlen = 1; 526 price = opt[cur - 1].price + ZSTD_getLiteralPrice(seqStorePtr, litlen, inr - 1); 527 } 528 529 if (cur > last_pos || price <= opt[cur].price) 530 SET_PRICE(cur, 1, 0, litlen, price); 531 532 if (cur == last_pos) 533 break; 534 535 if (inr > ilimit) /* last match must start at a minimum distance of 8 from oend */ 536 continue; 537 538 mlen = opt[cur].mlen; 539 if (opt[cur].off > ZSTD_REP_MOVE_OPT) { 540 opt[cur].rep[2] = opt[cur - mlen].rep[1]; 541 opt[cur].rep[1] = opt[cur - mlen].rep[0]; 542 opt[cur].rep[0] = opt[cur].off - ZSTD_REP_MOVE_OPT; 543 } else { 544 opt[cur].rep[2] = (opt[cur].off > 1) ? opt[cur - mlen].rep[1] : opt[cur - mlen].rep[2]; 545 opt[cur].rep[1] = (opt[cur].off > 0) ? opt[cur - mlen].rep[0] : opt[cur - mlen].rep[1]; 546 opt[cur].rep[0] = 547 ((opt[cur].off == ZSTD_REP_MOVE_OPT) && (mlen != 1)) ? (opt[cur - mlen].rep[0] - 1) : (opt[cur - mlen].rep[opt[cur].off]); 548 } 549 550 best_mlen = minMatch; 551 { 552 U32 i, last_i = ZSTD_REP_CHECK + (mlen != 1); 553 for (i = (opt[cur].mlen != 1); i < last_i; i++) { /* check rep */ 554 const S32 repCur = (i == ZSTD_REP_MOVE_OPT) ? (opt[cur].rep[0] - 1) : opt[cur].rep[i]; 555 if ((repCur > 0) && (repCur < (S32)(inr - prefixStart)) && 556 (ZSTD_readMINMATCH(inr, minMatch) == ZSTD_readMINMATCH(inr - repCur, minMatch))) { 557 mlen = (U32)ZSTD_count(inr + minMatch, inr + minMatch - repCur, iend) + minMatch; 558 559 if (mlen > sufficient_len || cur + mlen >= ZSTD_OPT_NUM) { 560 best_mlen = mlen; 561 best_off = i; 562 last_pos = cur + 1; 563 goto _storeSequence; 564 } 565 566 best_off = i - (opt[cur].mlen != 1); 567 if (mlen > best_mlen) 568 best_mlen = mlen; 569 570 do { 571 if (opt[cur].mlen == 1) { 572 litlen = opt[cur].litlen; 573 if (cur > litlen) { 574 price = opt[cur - litlen].price + ZSTD_getPrice(seqStorePtr, litlen, inr - litlen, 575 best_off, mlen - MINMATCH, ultra); 576 } else 577 price = ZSTD_getPrice(seqStorePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra); 578 } else { 579 litlen = 0; 580 price = opt[cur].price + ZSTD_getPrice(seqStorePtr, 0, NULL, best_off, mlen - MINMATCH, ultra); 581 } 582 583 if (cur + mlen > last_pos || price <= opt[cur + mlen].price) 584 SET_PRICE(cur + mlen, mlen, i, litlen, price); 585 mlen--; 586 } while (mlen >= minMatch); 587 } 588 } 589 } 590 591 match_num = ZSTD_BtGetAllMatches_selectMLS(ctx, inr, iend, maxSearches, mls, matches, best_mlen); 592 593 if (match_num > 0 && (matches[match_num - 1].len > sufficient_len || cur + matches[match_num - 1].len >= ZSTD_OPT_NUM)) { 594 best_mlen = matches[match_num - 1].len; 595 best_off = matches[match_num - 1].off; 596 last_pos = cur + 1; 597 goto _storeSequence; 598 } 599 600 /* set prices using matches at position = cur */ 601 for (u = 0; u < match_num; u++) { 602 mlen = (u > 0) ? matches[u - 1].len + 1 : best_mlen; 603 best_mlen = matches[u].len; 604 605 while (mlen <= best_mlen) { 606 if (opt[cur].mlen == 1) { 607 litlen = opt[cur].litlen; 608 if (cur > litlen) 609 price = opt[cur - litlen].price + ZSTD_getPrice(seqStorePtr, litlen, ip + cur - litlen, 610 matches[u].off - 1, mlen - MINMATCH, ultra); 611 else 612 price = ZSTD_getPrice(seqStorePtr, litlen, anchor, matches[u].off - 1, mlen - MINMATCH, ultra); 613 } else { 614 litlen = 0; 615 price = opt[cur].price + ZSTD_getPrice(seqStorePtr, 0, NULL, matches[u].off - 1, mlen - MINMATCH, ultra); 616 } 617 618 if (cur + mlen > last_pos || (price < opt[cur + mlen].price)) 619 SET_PRICE(cur + mlen, mlen, matches[u].off, litlen, price); 620 621 mlen++; 622 } 623 } 624 } 625 626 best_mlen = opt[last_pos].mlen; 627 best_off = opt[last_pos].off; 628 cur = last_pos - best_mlen; 629 630 /* store sequence */ 631_storeSequence: /* cur, last_pos, best_mlen, best_off have to be set */ 632 opt[0].mlen = 1; 633 634 while (1) { 635 mlen = opt[cur].mlen; 636 offset = opt[cur].off; 637 opt[cur].mlen = best_mlen; 638 opt[cur].off = best_off; 639 best_mlen = mlen; 640 best_off = offset; 641 if (mlen > cur) 642 break; 643 cur -= mlen; 644 } 645 646 for (u = 0; u <= last_pos;) { 647 u += opt[u].mlen; 648 } 649 650 for (cur = 0; cur < last_pos;) { 651 mlen = opt[cur].mlen; 652 if (mlen == 1) { 653 ip++; 654 cur++; 655 continue; 656 } 657 offset = opt[cur].off; 658 cur += mlen; 659 litLength = (U32)(ip - anchor); 660 661 if (offset > ZSTD_REP_MOVE_OPT) { 662 rep[2] = rep[1]; 663 rep[1] = rep[0]; 664 rep[0] = offset - ZSTD_REP_MOVE_OPT; 665 offset--; 666 } else { 667 if (offset != 0) { 668 best_off = (offset == ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : (rep[offset]); 669 if (offset != 1) 670 rep[2] = rep[1]; 671 rep[1] = rep[0]; 672 rep[0] = best_off; 673 } 674 if (litLength == 0) 675 offset--; 676 } 677 678 ZSTD_updatePrice(seqStorePtr, litLength, anchor, offset, mlen - MINMATCH); 679 ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, mlen - MINMATCH); 680 anchor = ip = ip + mlen; 681 } 682 } /* for (cur=0; cur < last_pos; ) */ 683 684 /* Save reps for next block */ 685 { 686 int i; 687 for (i = 0; i < ZSTD_REP_NUM; i++) 688 ctx->repToConfirm[i] = rep[i]; 689 } 690 691 /* Last Literals */ 692 { 693 size_t const lastLLSize = iend - anchor; 694 memcpy(seqStorePtr->lit, anchor, lastLLSize); 695 seqStorePtr->lit += lastLLSize; 696 } 697} 698 699FORCE_INLINE 700void ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx *ctx, const void *src, size_t srcSize, const int ultra) 701{ 702 seqStore_t *seqStorePtr = &(ctx->seqStore); 703 const BYTE *const istart = (const BYTE *)src; 704 const BYTE *ip = istart; 705 const BYTE *anchor = istart; 706 const BYTE *const iend = istart + srcSize; 707 const BYTE *const ilimit = iend - 8; 708 const BYTE *const base = ctx->base; 709 const U32 lowestIndex = ctx->lowLimit; 710 const U32 dictLimit = ctx->dictLimit; 711 const BYTE *const prefixStart = base + dictLimit; 712 const BYTE *const dictBase = ctx->dictBase; 713 const BYTE *const dictEnd = dictBase + dictLimit; 714 715 const U32 maxSearches = 1U << ctx->params.cParams.searchLog; 716 const U32 sufficient_len = ctx->params.cParams.targetLength; 717 const U32 mls = ctx->params.cParams.searchLength; 718 const U32 minMatch = (ctx->params.cParams.searchLength == 3) ? 3 : 4; 719 720 ZSTD_optimal_t *opt = seqStorePtr->priceTable; 721 ZSTD_match_t *matches = seqStorePtr->matchTable; 722 const BYTE *inr; 723 724 /* init */ 725 U32 offset, rep[ZSTD_REP_NUM]; 726 { 727 U32 i; 728 for (i = 0; i < ZSTD_REP_NUM; i++) 729 rep[i] = ctx->rep[i]; 730 } 731 732 ctx->nextToUpdate3 = ctx->nextToUpdate; 733 ZSTD_rescaleFreqs(seqStorePtr, (const BYTE *)src, srcSize); 734 ip += (ip == prefixStart); 735 736 /* Match Loop */ 737 while (ip < ilimit) { 738 U32 cur, match_num, last_pos, litlen, price; 739 U32 u, mlen, best_mlen, best_off, litLength; 740 U32 curr = (U32)(ip - base); 741 memset(opt, 0, sizeof(ZSTD_optimal_t)); 742 last_pos = 0; 743 opt[0].litlen = (U32)(ip - anchor); 744 745 /* check repCode */ 746 { 747 U32 i, last_i = ZSTD_REP_CHECK + (ip == anchor); 748 for (i = (ip == anchor); i < last_i; i++) { 749 const S32 repCur = (i == ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : rep[i]; 750 const U32 repIndex = (U32)(curr - repCur); 751 const BYTE *const repBase = repIndex < dictLimit ? dictBase : base; 752 const BYTE *const repMatch = repBase + repIndex; 753 if ((repCur > 0 && repCur <= (S32)curr) && 754 (((U32)((dictLimit - 1) - repIndex) >= 3) & (repIndex > lowestIndex)) /* intentional overflow */ 755 && (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch))) { 756 /* repcode detected we should take it */ 757 const BYTE *const repEnd = repIndex < dictLimit ? dictEnd : iend; 758 mlen = (U32)ZSTD_count_2segments(ip + minMatch, repMatch + minMatch, iend, repEnd, prefixStart) + minMatch; 759 760 if (mlen > sufficient_len || mlen >= ZSTD_OPT_NUM) { 761 best_mlen = mlen; 762 best_off = i; 763 cur = 0; 764 last_pos = 1; 765 goto _storeSequence; 766 } 767 768 best_off = i - (ip == anchor); 769 litlen = opt[0].litlen; 770 do { 771 price = ZSTD_getPrice(seqStorePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra); 772 if (mlen > last_pos || price < opt[mlen].price) 773 SET_PRICE(mlen, mlen, i, litlen, price); /* note : macro modifies last_pos */ 774 mlen--; 775 } while (mlen >= minMatch); 776 } 777 } 778 } 779 780 match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, ip, iend, maxSearches, mls, matches, minMatch); /* first search (depth 0) */ 781 782 if (!last_pos && !match_num) { 783 ip++; 784 continue; 785 } 786 787 { 788 U32 i; 789 for (i = 0; i < ZSTD_REP_NUM; i++) 790 opt[0].rep[i] = rep[i]; 791 } 792 opt[0].mlen = 1; 793 794 if (match_num && (matches[match_num - 1].len > sufficient_len || matches[match_num - 1].len >= ZSTD_OPT_NUM)) { 795 best_mlen = matches[match_num - 1].len; 796 best_off = matches[match_num - 1].off; 797 cur = 0; 798 last_pos = 1; 799 goto _storeSequence; 800 } 801 802 best_mlen = (last_pos) ? last_pos : minMatch; 803 804 /* set prices using matches at position = 0 */ 805 for (u = 0; u < match_num; u++) { 806 mlen = (u > 0) ? matches[u - 1].len + 1 : best_mlen; 807 best_mlen = matches[u].len; 808 litlen = opt[0].litlen; 809 while (mlen <= best_mlen) { 810 price = ZSTD_getPrice(seqStorePtr, litlen, anchor, matches[u].off - 1, mlen - MINMATCH, ultra); 811 if (mlen > last_pos || price < opt[mlen].price) 812 SET_PRICE(mlen, mlen, matches[u].off, litlen, price); 813 mlen++; 814 } 815 } 816 817 if (last_pos < minMatch) { 818 ip++; 819 continue; 820 } 821 822 /* check further positions */ 823 for (cur = 1; cur <= last_pos; cur++) { 824 inr = ip + cur; 825 826 if (opt[cur - 1].mlen == 1) { 827 litlen = opt[cur - 1].litlen + 1; 828 if (cur > litlen) { 829 price = opt[cur - litlen].price + ZSTD_getLiteralPrice(seqStorePtr, litlen, inr - litlen); 830 } else 831 price = ZSTD_getLiteralPrice(seqStorePtr, litlen, anchor); 832 } else { 833 litlen = 1; 834 price = opt[cur - 1].price + ZSTD_getLiteralPrice(seqStorePtr, litlen, inr - 1); 835 } 836 837 if (cur > last_pos || price <= opt[cur].price) 838 SET_PRICE(cur, 1, 0, litlen, price); 839 840 if (cur == last_pos) 841 break; 842 843 if (inr > ilimit) /* last match must start at a minimum distance of 8 from oend */ 844 continue; 845 846 mlen = opt[cur].mlen; 847 if (opt[cur].off > ZSTD_REP_MOVE_OPT) { 848 opt[cur].rep[2] = opt[cur - mlen].rep[1]; 849 opt[cur].rep[1] = opt[cur - mlen].rep[0]; 850 opt[cur].rep[0] = opt[cur].off - ZSTD_REP_MOVE_OPT; 851 } else { 852 opt[cur].rep[2] = (opt[cur].off > 1) ? opt[cur - mlen].rep[1] : opt[cur - mlen].rep[2]; 853 opt[cur].rep[1] = (opt[cur].off > 0) ? opt[cur - mlen].rep[0] : opt[cur - mlen].rep[1]; 854 opt[cur].rep[0] = 855 ((opt[cur].off == ZSTD_REP_MOVE_OPT) && (mlen != 1)) ? (opt[cur - mlen].rep[0] - 1) : (opt[cur - mlen].rep[opt[cur].off]); 856 } 857 858 best_mlen = minMatch; 859 { 860 U32 i, last_i = ZSTD_REP_CHECK + (mlen != 1); 861 for (i = (mlen != 1); i < last_i; i++) { 862 const S32 repCur = (i == ZSTD_REP_MOVE_OPT) ? (opt[cur].rep[0] - 1) : opt[cur].rep[i]; 863 const U32 repIndex = (U32)(curr + cur - repCur); 864 const BYTE *const repBase = repIndex < dictLimit ? dictBase : base; 865 const BYTE *const repMatch = repBase + repIndex; 866 if ((repCur > 0 && repCur <= (S32)(curr + cur)) && 867 (((U32)((dictLimit - 1) - repIndex) >= 3) & (repIndex > lowestIndex)) /* intentional overflow */ 868 && (ZSTD_readMINMATCH(inr, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch))) { 869 /* repcode detected */ 870 const BYTE *const repEnd = repIndex < dictLimit ? dictEnd : iend; 871 mlen = (U32)ZSTD_count_2segments(inr + minMatch, repMatch + minMatch, iend, repEnd, prefixStart) + minMatch; 872 873 if (mlen > sufficient_len || cur + mlen >= ZSTD_OPT_NUM) { 874 best_mlen = mlen; 875 best_off = i; 876 last_pos = cur + 1; 877 goto _storeSequence; 878 } 879 880 best_off = i - (opt[cur].mlen != 1); 881 if (mlen > best_mlen) 882 best_mlen = mlen; 883 884 do { 885 if (opt[cur].mlen == 1) { 886 litlen = opt[cur].litlen; 887 if (cur > litlen) { 888 price = opt[cur - litlen].price + ZSTD_getPrice(seqStorePtr, litlen, inr - litlen, 889 best_off, mlen - MINMATCH, ultra); 890 } else 891 price = ZSTD_getPrice(seqStorePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra); 892 } else { 893 litlen = 0; 894 price = opt[cur].price + ZSTD_getPrice(seqStorePtr, 0, NULL, best_off, mlen - MINMATCH, ultra); 895 } 896 897 if (cur + mlen > last_pos || price <= opt[cur + mlen].price) 898 SET_PRICE(cur + mlen, mlen, i, litlen, price); 899 mlen--; 900 } while (mlen >= minMatch); 901 } 902 } 903 } 904 905 match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, inr, iend, maxSearches, mls, matches, minMatch); 906 907 if (match_num > 0 && (matches[match_num - 1].len > sufficient_len || cur + matches[match_num - 1].len >= ZSTD_OPT_NUM)) { 908 best_mlen = matches[match_num - 1].len; 909 best_off = matches[match_num - 1].off; 910 last_pos = cur + 1; 911 goto _storeSequence; 912 } 913 914 /* set prices using matches at position = cur */ 915 for (u = 0; u < match_num; u++) { 916 mlen = (u > 0) ? matches[u - 1].len + 1 : best_mlen; 917 best_mlen = matches[u].len; 918 919 while (mlen <= best_mlen) { 920 if (opt[cur].mlen == 1) { 921 litlen = opt[cur].litlen; 922 if (cur > litlen) 923 price = opt[cur - litlen].price + ZSTD_getPrice(seqStorePtr, litlen, ip + cur - litlen, 924 matches[u].off - 1, mlen - MINMATCH, ultra); 925 else 926 price = ZSTD_getPrice(seqStorePtr, litlen, anchor, matches[u].off - 1, mlen - MINMATCH, ultra); 927 } else { 928 litlen = 0; 929 price = opt[cur].price + ZSTD_getPrice(seqStorePtr, 0, NULL, matches[u].off - 1, mlen - MINMATCH, ultra); 930 } 931 932 if (cur + mlen > last_pos || (price < opt[cur + mlen].price)) 933 SET_PRICE(cur + mlen, mlen, matches[u].off, litlen, price); 934 935 mlen++; 936 } 937 } 938 } /* for (cur = 1; cur <= last_pos; cur++) */ 939 940 best_mlen = opt[last_pos].mlen; 941 best_off = opt[last_pos].off; 942 cur = last_pos - best_mlen; 943 944 /* store sequence */ 945_storeSequence: /* cur, last_pos, best_mlen, best_off have to be set */ 946 opt[0].mlen = 1; 947 948 while (1) { 949 mlen = opt[cur].mlen; 950 offset = opt[cur].off; 951 opt[cur].mlen = best_mlen; 952 opt[cur].off = best_off; 953 best_mlen = mlen; 954 best_off = offset; 955 if (mlen > cur) 956 break; 957 cur -= mlen; 958 } 959 960 for (u = 0; u <= last_pos;) { 961 u += opt[u].mlen; 962 } 963 964 for (cur = 0; cur < last_pos;) { 965 mlen = opt[cur].mlen; 966 if (mlen == 1) { 967 ip++; 968 cur++; 969 continue; 970 } 971 offset = opt[cur].off; 972 cur += mlen; 973 litLength = (U32)(ip - anchor); 974 975 if (offset > ZSTD_REP_MOVE_OPT) { 976 rep[2] = rep[1]; 977 rep[1] = rep[0]; 978 rep[0] = offset - ZSTD_REP_MOVE_OPT; 979 offset--; 980 } else { 981 if (offset != 0) { 982 best_off = (offset == ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : (rep[offset]); 983 if (offset != 1) 984 rep[2] = rep[1]; 985 rep[1] = rep[0]; 986 rep[0] = best_off; 987 } 988 989 if (litLength == 0) 990 offset--; 991 } 992 993 ZSTD_updatePrice(seqStorePtr, litLength, anchor, offset, mlen - MINMATCH); 994 ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, mlen - MINMATCH); 995 anchor = ip = ip + mlen; 996 } 997 } /* for (cur=0; cur < last_pos; ) */ 998 999 /* Save reps for next block */ 1000 { 1001 int i; 1002 for (i = 0; i < ZSTD_REP_NUM; i++) 1003 ctx->repToConfirm[i] = rep[i]; 1004 } 1005 1006 /* Last Literals */ 1007 { 1008 size_t lastLLSize = iend - anchor; 1009 memcpy(seqStorePtr->lit, anchor, lastLLSize); 1010 seqStorePtr->lit += lastLLSize; 1011 } 1012} 1013 1014#endif /* ZSTD_OPT_H_91842398743 */ 1015