Scott Baker | e7144bc | 2019-10-01 14:16:47 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (c) 2016-present, Przemyslaw Skibinski, 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_opt.h" |
| 13 | |
| 14 | |
| 15 | #define ZSTD_LITFREQ_ADD 2 /* scaling factor for litFreq, so that frequencies adapt faster to new stats. Also used for matchSum (?) */ |
| 16 | #define ZSTD_FREQ_DIV 4 /* log factor when using previous stats to init next stats */ |
| 17 | #define ZSTD_MAX_PRICE (1<<30) |
| 18 | |
| 19 | |
| 20 | /*-************************************* |
| 21 | * Price functions for optimal parser |
| 22 | ***************************************/ |
| 23 | static void ZSTD_setLog2Prices(optState_t* optPtr) |
| 24 | { |
| 25 | optPtr->log2litSum = ZSTD_highbit32(optPtr->litSum+1); |
| 26 | optPtr->log2litLengthSum = ZSTD_highbit32(optPtr->litLengthSum+1); |
| 27 | optPtr->log2matchLengthSum = ZSTD_highbit32(optPtr->matchLengthSum+1); |
| 28 | optPtr->log2offCodeSum = ZSTD_highbit32(optPtr->offCodeSum+1); |
| 29 | } |
| 30 | |
| 31 | |
| 32 | static void ZSTD_rescaleFreqs(optState_t* const optPtr, |
| 33 | const BYTE* const src, size_t const srcSize) |
| 34 | { |
| 35 | optPtr->staticPrices = 0; |
| 36 | |
| 37 | if (optPtr->litLengthSum == 0) { /* first init */ |
| 38 | unsigned u; |
| 39 | if (srcSize <= 1024) optPtr->staticPrices = 1; |
| 40 | |
| 41 | assert(optPtr->litFreq!=NULL); |
| 42 | for (u=0; u<=MaxLit; u++) |
| 43 | optPtr->litFreq[u] = 0; |
| 44 | for (u=0; u<srcSize; u++) |
| 45 | optPtr->litFreq[src[u]]++; |
| 46 | optPtr->litSum = 0; |
| 47 | for (u=0; u<=MaxLit; u++) { |
| 48 | optPtr->litFreq[u] = 1 + (optPtr->litFreq[u] >> ZSTD_FREQ_DIV); |
| 49 | optPtr->litSum += optPtr->litFreq[u]; |
| 50 | } |
| 51 | |
| 52 | for (u=0; u<=MaxLL; u++) |
| 53 | optPtr->litLengthFreq[u] = 1; |
| 54 | optPtr->litLengthSum = MaxLL+1; |
| 55 | for (u=0; u<=MaxML; u++) |
| 56 | optPtr->matchLengthFreq[u] = 1; |
| 57 | optPtr->matchLengthSum = MaxML+1; |
| 58 | for (u=0; u<=MaxOff; u++) |
| 59 | optPtr->offCodeFreq[u] = 1; |
| 60 | optPtr->offCodeSum = (MaxOff+1); |
| 61 | |
| 62 | } else { |
| 63 | unsigned u; |
| 64 | |
| 65 | optPtr->litSum = 0; |
| 66 | for (u=0; u<=MaxLit; u++) { |
| 67 | optPtr->litFreq[u] = 1 + (optPtr->litFreq[u] >> (ZSTD_FREQ_DIV+1)); |
| 68 | optPtr->litSum += optPtr->litFreq[u]; |
| 69 | } |
| 70 | optPtr->litLengthSum = 0; |
| 71 | for (u=0; u<=MaxLL; u++) { |
| 72 | optPtr->litLengthFreq[u] = 1 + (optPtr->litLengthFreq[u]>>(ZSTD_FREQ_DIV+1)); |
| 73 | optPtr->litLengthSum += optPtr->litLengthFreq[u]; |
| 74 | } |
| 75 | optPtr->matchLengthSum = 0; |
| 76 | for (u=0; u<=MaxML; u++) { |
| 77 | optPtr->matchLengthFreq[u] = 1 + (optPtr->matchLengthFreq[u]>>ZSTD_FREQ_DIV); |
| 78 | optPtr->matchLengthSum += optPtr->matchLengthFreq[u]; |
| 79 | } |
| 80 | optPtr->offCodeSum = 0; |
| 81 | for (u=0; u<=MaxOff; u++) { |
| 82 | optPtr->offCodeFreq[u] = 1 + (optPtr->offCodeFreq[u]>>ZSTD_FREQ_DIV); |
| 83 | optPtr->offCodeSum += optPtr->offCodeFreq[u]; |
| 84 | } |
| 85 | } |
| 86 | |
| 87 | ZSTD_setLog2Prices(optPtr); |
| 88 | } |
| 89 | |
| 90 | |
| 91 | /* ZSTD_rawLiteralsCost() : |
| 92 | * cost of literals (only) in given segment (which length can be null) |
| 93 | * does not include cost of literalLength symbol */ |
| 94 | static U32 ZSTD_rawLiteralsCost(const BYTE* const literals, U32 const litLength, |
| 95 | const optState_t* const optPtr) |
| 96 | { |
| 97 | if (optPtr->staticPrices) return (litLength*6); /* 6 bit per literal - no statistic used */ |
| 98 | if (litLength == 0) return 0; |
| 99 | |
| 100 | /* literals */ |
| 101 | { U32 u; |
| 102 | U32 cost = litLength * optPtr->log2litSum; |
| 103 | for (u=0; u < litLength; u++) |
| 104 | cost -= ZSTD_highbit32(optPtr->litFreq[literals[u]]+1); |
| 105 | return cost; |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | /* ZSTD_litLengthPrice() : |
| 110 | * cost of literalLength symbol */ |
| 111 | static U32 ZSTD_litLengthPrice(U32 const litLength, const optState_t* const optPtr) |
| 112 | { |
| 113 | if (optPtr->staticPrices) return ZSTD_highbit32((U32)litLength+1); |
| 114 | |
| 115 | /* literal Length */ |
| 116 | { U32 const llCode = ZSTD_LLcode(litLength); |
| 117 | U32 const price = LL_bits[llCode] + optPtr->log2litLengthSum - ZSTD_highbit32(optPtr->litLengthFreq[llCode]+1); |
| 118 | return price; |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | /* ZSTD_litLengthPrice() : |
| 123 | * cost of the literal part of a sequence, |
| 124 | * including literals themselves, and literalLength symbol */ |
| 125 | static U32 ZSTD_fullLiteralsCost(const BYTE* const literals, U32 const litLength, |
| 126 | const optState_t* const optPtr) |
| 127 | { |
| 128 | return ZSTD_rawLiteralsCost(literals, litLength, optPtr) |
| 129 | + ZSTD_litLengthPrice(litLength, optPtr); |
| 130 | } |
| 131 | |
| 132 | /* ZSTD_litLengthContribution() : |
| 133 | * @return ( cost(litlength) - cost(0) ) |
| 134 | * this value can then be added to rawLiteralsCost() |
| 135 | * to provide a cost which is directly comparable to a match ending at same position */ |
| 136 | static int ZSTD_litLengthContribution(U32 const litLength, const optState_t* const optPtr) |
| 137 | { |
| 138 | if (optPtr->staticPrices) return ZSTD_highbit32(litLength+1); |
| 139 | |
| 140 | /* literal Length */ |
| 141 | { U32 const llCode = ZSTD_LLcode(litLength); |
| 142 | int const contribution = LL_bits[llCode] |
| 143 | + ZSTD_highbit32(optPtr->litLengthFreq[0]+1) |
| 144 | - ZSTD_highbit32(optPtr->litLengthFreq[llCode]+1); |
| 145 | #if 1 |
| 146 | return contribution; |
| 147 | #else |
| 148 | return MAX(0, contribution); /* sometimes better, sometimes not ... */ |
| 149 | #endif |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | /* ZSTD_literalsContribution() : |
| 154 | * creates a fake cost for the literals part of a sequence |
| 155 | * which can be compared to the ending cost of a match |
| 156 | * should a new match start at this position */ |
| 157 | static int ZSTD_literalsContribution(const BYTE* const literals, U32 const litLength, |
| 158 | const optState_t* const optPtr) |
| 159 | { |
| 160 | int const contribution = ZSTD_rawLiteralsCost(literals, litLength, optPtr) |
| 161 | + ZSTD_litLengthContribution(litLength, optPtr); |
| 162 | return contribution; |
| 163 | } |
| 164 | |
| 165 | /* ZSTD_getMatchPrice() : |
| 166 | * Provides the cost of the match part (offset + matchLength) of a sequence |
| 167 | * Must be combined with ZSTD_fullLiteralsCost() to get the full cost of a sequence. |
| 168 | * optLevel: when <2, favors small offset for decompression speed (improved cache efficiency) */ |
| 169 | FORCE_INLINE_TEMPLATE U32 ZSTD_getMatchPrice( |
| 170 | U32 const offset, U32 const matchLength, |
| 171 | const optState_t* const optPtr, |
| 172 | int const optLevel) |
| 173 | { |
| 174 | U32 price; |
| 175 | U32 const offCode = ZSTD_highbit32(offset+1); |
| 176 | U32 const mlBase = matchLength - MINMATCH; |
| 177 | assert(matchLength >= MINMATCH); |
| 178 | |
| 179 | if (optPtr->staticPrices) /* fixed scheme, do not use statistics */ |
| 180 | return ZSTD_highbit32((U32)mlBase+1) + 16 + offCode; |
| 181 | |
| 182 | price = offCode + optPtr->log2offCodeSum - ZSTD_highbit32(optPtr->offCodeFreq[offCode]+1); |
| 183 | if ((optLevel<2) /*static*/ && offCode >= 20) price += (offCode-19)*2; /* handicap for long distance offsets, favor decompression speed */ |
| 184 | |
| 185 | /* match Length */ |
| 186 | { U32 const mlCode = ZSTD_MLcode(mlBase); |
| 187 | price += ML_bits[mlCode] + optPtr->log2matchLengthSum - ZSTD_highbit32(optPtr->matchLengthFreq[mlCode]+1); |
| 188 | } |
| 189 | |
| 190 | DEBUGLOG(8, "ZSTD_getMatchPrice(ml:%u) = %u", matchLength, price); |
| 191 | return price; |
| 192 | } |
| 193 | |
| 194 | static void ZSTD_updateStats(optState_t* const optPtr, |
| 195 | U32 litLength, const BYTE* literals, |
| 196 | U32 offsetCode, U32 matchLength) |
| 197 | { |
| 198 | /* literals */ |
| 199 | { U32 u; |
| 200 | for (u=0; u < litLength; u++) |
| 201 | optPtr->litFreq[literals[u]] += ZSTD_LITFREQ_ADD; |
| 202 | optPtr->litSum += litLength*ZSTD_LITFREQ_ADD; |
| 203 | } |
| 204 | |
| 205 | /* literal Length */ |
| 206 | { U32 const llCode = ZSTD_LLcode(litLength); |
| 207 | optPtr->litLengthFreq[llCode]++; |
| 208 | optPtr->litLengthSum++; |
| 209 | } |
| 210 | |
| 211 | /* match offset code (0-2=>repCode; 3+=>offset+2) */ |
| 212 | { U32 const offCode = ZSTD_highbit32(offsetCode+1); |
| 213 | assert(offCode <= MaxOff); |
| 214 | optPtr->offCodeFreq[offCode]++; |
| 215 | optPtr->offCodeSum++; |
| 216 | } |
| 217 | |
| 218 | /* match Length */ |
| 219 | { U32 const mlBase = matchLength - MINMATCH; |
| 220 | U32 const mlCode = ZSTD_MLcode(mlBase); |
| 221 | optPtr->matchLengthFreq[mlCode]++; |
| 222 | optPtr->matchLengthSum++; |
| 223 | } |
| 224 | } |
| 225 | |
| 226 | |
| 227 | /* ZSTD_readMINMATCH() : |
| 228 | * function safe only for comparisons |
| 229 | * assumption : memPtr must be at least 4 bytes before end of buffer */ |
| 230 | MEM_STATIC U32 ZSTD_readMINMATCH(const void* memPtr, U32 length) |
| 231 | { |
| 232 | switch (length) |
| 233 | { |
| 234 | default : |
| 235 | case 4 : return MEM_read32(memPtr); |
| 236 | case 3 : if (MEM_isLittleEndian()) |
| 237 | return MEM_read32(memPtr)<<8; |
| 238 | else |
| 239 | return MEM_read32(memPtr)>>8; |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | |
| 244 | /* Update hashTable3 up to ip (excluded) |
| 245 | Assumption : always within prefix (i.e. not within extDict) */ |
| 246 | static U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_matchState_t* ms, const BYTE* const ip) |
| 247 | { |
| 248 | U32* const hashTable3 = ms->hashTable3; |
| 249 | U32 const hashLog3 = ms->hashLog3; |
| 250 | const BYTE* const base = ms->window.base; |
| 251 | U32 idx = ms->nextToUpdate3; |
| 252 | U32 const target = ms->nextToUpdate3 = (U32)(ip - base); |
| 253 | size_t const hash3 = ZSTD_hash3Ptr(ip, hashLog3); |
| 254 | assert(hashLog3 > 0); |
| 255 | |
| 256 | while(idx < target) { |
| 257 | hashTable3[ZSTD_hash3Ptr(base+idx, hashLog3)] = idx; |
| 258 | idx++; |
| 259 | } |
| 260 | |
| 261 | return hashTable3[hash3]; |
| 262 | } |
| 263 | |
| 264 | |
| 265 | /*-************************************* |
| 266 | * Binary Tree search |
| 267 | ***************************************/ |
| 268 | /** ZSTD_insertBt1() : add one or multiple positions to tree. |
| 269 | * ip : assumed <= iend-8 . |
| 270 | * @return : nb of positions added */ |
| 271 | static U32 ZSTD_insertBt1( |
| 272 | ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams, |
| 273 | const BYTE* const ip, const BYTE* const iend, |
| 274 | U32 const mls, U32 const extDict) |
| 275 | { |
| 276 | U32* const hashTable = ms->hashTable; |
| 277 | U32 const hashLog = cParams->hashLog; |
| 278 | size_t const h = ZSTD_hashPtr(ip, hashLog, mls); |
| 279 | U32* const bt = ms->chainTable; |
| 280 | U32 const btLog = cParams->chainLog - 1; |
| 281 | U32 const btMask = (1 << btLog) - 1; |
| 282 | U32 matchIndex = hashTable[h]; |
| 283 | size_t commonLengthSmaller=0, commonLengthLarger=0; |
| 284 | const BYTE* const base = ms->window.base; |
| 285 | const BYTE* const dictBase = ms->window.dictBase; |
| 286 | const U32 dictLimit = ms->window.dictLimit; |
| 287 | const BYTE* const dictEnd = dictBase + dictLimit; |
| 288 | const BYTE* const prefixStart = base + dictLimit; |
| 289 | const BYTE* match; |
| 290 | const U32 current = (U32)(ip-base); |
| 291 | const U32 btLow = btMask >= current ? 0 : current - btMask; |
| 292 | U32* smallerPtr = bt + 2*(current&btMask); |
| 293 | U32* largerPtr = smallerPtr + 1; |
| 294 | U32 dummy32; /* to be nullified at the end */ |
| 295 | U32 const windowLow = ms->window.lowLimit; |
| 296 | U32 matchEndIdx = current+8+1; |
| 297 | size_t bestLength = 8; |
| 298 | U32 nbCompares = 1U << cParams->searchLog; |
| 299 | #ifdef ZSTD_C_PREDICT |
| 300 | U32 predictedSmall = *(bt + 2*((current-1)&btMask) + 0); |
| 301 | U32 predictedLarge = *(bt + 2*((current-1)&btMask) + 1); |
| 302 | predictedSmall += (predictedSmall>0); |
| 303 | predictedLarge += (predictedLarge>0); |
| 304 | #endif /* ZSTD_C_PREDICT */ |
| 305 | |
| 306 | DEBUGLOG(8, "ZSTD_insertBt1 (%u)", current); |
| 307 | |
| 308 | assert(ip <= iend-8); /* required for h calculation */ |
| 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 | assert(matchIndex < current); |
| 315 | |
| 316 | #ifdef ZSTD_C_PREDICT /* note : can create issues when hlog small <= 11 */ |
| 317 | const U32* predictPtr = bt + 2*((matchIndex-1) & btMask); /* written this way, as bt is a roll buffer */ |
| 318 | if (matchIndex == predictedSmall) { |
| 319 | /* no need to check length, result known */ |
| 320 | *smallerPtr = matchIndex; |
| 321 | if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */ |
| 322 | smallerPtr = nextPtr+1; /* new "smaller" => larger of match */ |
| 323 | matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */ |
| 324 | predictedSmall = predictPtr[1] + (predictPtr[1]>0); |
| 325 | continue; |
| 326 | } |
| 327 | if (matchIndex == predictedLarge) { |
| 328 | *largerPtr = matchIndex; |
| 329 | if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */ |
| 330 | largerPtr = nextPtr; |
| 331 | matchIndex = nextPtr[0]; |
| 332 | predictedLarge = predictPtr[0] + (predictPtr[0]>0); |
| 333 | continue; |
| 334 | } |
| 335 | #endif |
| 336 | |
| 337 | if ((!extDict) || (matchIndex+matchLength >= dictLimit)) { |
| 338 | assert(matchIndex+matchLength >= dictLimit); /* might be wrong if extDict is incorrectly set to 0 */ |
| 339 | match = base + matchIndex; |
| 340 | matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend); |
| 341 | } else { |
| 342 | match = dictBase + matchIndex; |
| 343 | matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart); |
| 344 | if (matchIndex+matchLength >= dictLimit) |
| 345 | match = base + matchIndex; /* to prepare for next usage of match[matchLength] */ |
| 346 | } |
| 347 | |
| 348 | if (matchLength > bestLength) { |
| 349 | bestLength = matchLength; |
| 350 | if (matchLength > matchEndIdx - matchIndex) |
| 351 | matchEndIdx = matchIndex + (U32)matchLength; |
| 352 | } |
| 353 | |
| 354 | if (ip+matchLength == iend) { /* equal : no way to know if inf or sup */ |
| 355 | break; /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt tree */ |
| 356 | } |
| 357 | |
| 358 | if (match[matchLength] < ip[matchLength]) { /* necessarily within buffer */ |
| 359 | /* match is smaller than current */ |
| 360 | *smallerPtr = matchIndex; /* update smaller idx */ |
| 361 | commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */ |
| 362 | if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop searching */ |
| 363 | smallerPtr = nextPtr+1; /* new "candidate" => larger than match, which was smaller than target */ |
| 364 | matchIndex = nextPtr[1]; /* new matchIndex, larger than previous and closer to current */ |
| 365 | } else { |
| 366 | /* match is larger than current */ |
| 367 | *largerPtr = matchIndex; |
| 368 | commonLengthLarger = matchLength; |
| 369 | if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop searching */ |
| 370 | largerPtr = nextPtr; |
| 371 | matchIndex = nextPtr[0]; |
| 372 | } } |
| 373 | |
| 374 | *smallerPtr = *largerPtr = 0; |
| 375 | if (bestLength > 384) return MIN(192, (U32)(bestLength - 384)); /* speed optimization */ |
| 376 | assert(matchEndIdx > current + 8); |
| 377 | return matchEndIdx - (current + 8); |
| 378 | } |
| 379 | |
| 380 | FORCE_INLINE_TEMPLATE |
| 381 | void ZSTD_updateTree_internal( |
| 382 | ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams, |
| 383 | const BYTE* const ip, const BYTE* const iend, |
| 384 | const U32 mls, const U32 extDict) |
| 385 | { |
| 386 | const BYTE* const base = ms->window.base; |
| 387 | U32 const target = (U32)(ip - base); |
| 388 | U32 idx = ms->nextToUpdate; |
| 389 | DEBUGLOG(7, "ZSTD_updateTree_internal, from %u to %u (extDict:%u)", |
| 390 | idx, target, extDict); |
| 391 | |
| 392 | while(idx < target) |
| 393 | idx += ZSTD_insertBt1(ms, cParams, base+idx, iend, mls, extDict); |
| 394 | ms->nextToUpdate = target; |
| 395 | } |
| 396 | |
| 397 | void ZSTD_updateTree( |
| 398 | ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams, |
| 399 | const BYTE* ip, const BYTE* iend) |
| 400 | { |
| 401 | ZSTD_updateTree_internal(ms, cParams, ip, iend, cParams->searchLength, 0 /*extDict*/); |
| 402 | } |
| 403 | |
| 404 | FORCE_INLINE_TEMPLATE |
| 405 | U32 ZSTD_insertBtAndGetAllMatches ( |
| 406 | ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams, |
| 407 | const BYTE* const ip, const BYTE* const iLimit, int const extDict, |
| 408 | U32 rep[ZSTD_REP_NUM], U32 const ll0, |
| 409 | ZSTD_match_t* matches, const U32 lengthToBeat, U32 const mls /* template */) |
| 410 | { |
| 411 | U32 const sufficient_len = MIN(cParams->targetLength, ZSTD_OPT_NUM -1); |
| 412 | const BYTE* const base = ms->window.base; |
| 413 | U32 const current = (U32)(ip-base); |
| 414 | U32 const hashLog = cParams->hashLog; |
| 415 | U32 const minMatch = (mls==3) ? 3 : 4; |
| 416 | U32* const hashTable = ms->hashTable; |
| 417 | size_t const h = ZSTD_hashPtr(ip, hashLog, mls); |
| 418 | U32 matchIndex = hashTable[h]; |
| 419 | U32* const bt = ms->chainTable; |
| 420 | U32 const btLog = cParams->chainLog - 1; |
| 421 | U32 const btMask= (1U << btLog) - 1; |
| 422 | size_t commonLengthSmaller=0, commonLengthLarger=0; |
| 423 | const BYTE* const dictBase = ms->window.dictBase; |
| 424 | U32 const dictLimit = ms->window.dictLimit; |
| 425 | const BYTE* const dictEnd = dictBase + dictLimit; |
| 426 | const BYTE* const prefixStart = base + dictLimit; |
| 427 | U32 const btLow = btMask >= current ? 0 : current - btMask; |
| 428 | U32 const windowLow = ms->window.lowLimit; |
| 429 | U32* smallerPtr = bt + 2*(current&btMask); |
| 430 | U32* largerPtr = bt + 2*(current&btMask) + 1; |
| 431 | U32 matchEndIdx = current+8+1; /* farthest referenced position of any match => detects repetitive patterns */ |
| 432 | U32 dummy32; /* to be nullified at the end */ |
| 433 | U32 mnum = 0; |
| 434 | U32 nbCompares = 1U << cParams->searchLog; |
| 435 | |
| 436 | size_t bestLength = lengthToBeat-1; |
| 437 | DEBUGLOG(7, "ZSTD_insertBtAndGetAllMatches"); |
| 438 | |
| 439 | /* check repCode */ |
| 440 | { U32 const lastR = ZSTD_REP_NUM + ll0; |
| 441 | U32 repCode; |
| 442 | for (repCode = ll0; repCode < lastR; repCode++) { |
| 443 | U32 const repOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode]; |
| 444 | U32 const repIndex = current - repOffset; |
| 445 | U32 repLen = 0; |
| 446 | assert(current >= dictLimit); |
| 447 | if (repOffset-1 /* intentional overflow, discards 0 and -1 */ < current-dictLimit) { /* equivalent to `current > repIndex >= dictLimit` */ |
| 448 | if (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(ip - repOffset, minMatch)) { |
| 449 | repLen = (U32)ZSTD_count(ip+minMatch, ip+minMatch-repOffset, iLimit) + minMatch; |
| 450 | } |
| 451 | } else { /* repIndex < dictLimit || repIndex >= current */ |
| 452 | const BYTE* const repMatch = dictBase + repIndex; |
| 453 | assert(current >= windowLow); |
| 454 | if ( extDict /* this case only valid in extDict mode */ |
| 455 | && ( ((repOffset-1) /*intentional overflow*/ < current - windowLow) /* equivalent to `current > repIndex >= windowLow` */ |
| 456 | & (((U32)((dictLimit-1) - repIndex) >= 3) ) /* intentional overflow : do not test positions overlapping 2 memory segments */) |
| 457 | && (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch)) ) { |
| 458 | repLen = (U32)ZSTD_count_2segments(ip+minMatch, repMatch+minMatch, iLimit, dictEnd, prefixStart) + minMatch; |
| 459 | } } |
| 460 | /* save longer solution */ |
| 461 | if (repLen > bestLength) { |
| 462 | DEBUGLOG(8, "found rep-match %u of length %u", |
| 463 | repCode - ll0, (U32)repLen); |
| 464 | bestLength = repLen; |
| 465 | matches[mnum].off = repCode - ll0; |
| 466 | matches[mnum].len = (U32)repLen; |
| 467 | mnum++; |
| 468 | if ( (repLen > sufficient_len) |
| 469 | | (ip+repLen == iLimit) ) { /* best possible */ |
| 470 | return mnum; |
| 471 | } } } } |
| 472 | |
| 473 | /* HC3 match finder */ |
| 474 | if ((mls == 3) /*static*/ && (bestLength < mls)) { |
| 475 | U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3(ms, ip); |
| 476 | if ((matchIndex3 > windowLow) |
| 477 | & (current - matchIndex3 < (1<<18)) /*heuristic : longer distance likely too expensive*/ ) { |
| 478 | size_t mlen; |
| 479 | if ((!extDict) /*static*/ || (matchIndex3 >= dictLimit)) { |
| 480 | const BYTE* const match = base + matchIndex3; |
| 481 | mlen = ZSTD_count(ip, match, iLimit); |
| 482 | } else { |
| 483 | const BYTE* const match = dictBase + matchIndex3; |
| 484 | mlen = ZSTD_count_2segments(ip, match, iLimit, dictEnd, prefixStart); |
| 485 | } |
| 486 | |
| 487 | /* save best solution */ |
| 488 | if (mlen >= mls /* == 3 > bestLength */) { |
| 489 | DEBUGLOG(8, "found small match with hlog3, of length %u", |
| 490 | (U32)mlen); |
| 491 | bestLength = mlen; |
| 492 | assert(current > matchIndex3); |
| 493 | assert(mnum==0); /* no prior solution */ |
| 494 | matches[0].off = (current - matchIndex3) + ZSTD_REP_MOVE; |
| 495 | matches[0].len = (U32)mlen; |
| 496 | mnum = 1; |
| 497 | if ( (mlen > sufficient_len) | |
| 498 | (ip+mlen == iLimit) ) { /* best possible length */ |
| 499 | ms->nextToUpdate = current+1; /* skip insertion */ |
| 500 | return 1; |
| 501 | } } } } |
| 502 | |
| 503 | hashTable[h] = current; /* Update Hash Table */ |
| 504 | |
| 505 | while (nbCompares-- && (matchIndex > windowLow)) { |
| 506 | U32* const nextPtr = bt + 2*(matchIndex & btMask); |
| 507 | size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */ |
| 508 | const BYTE* match; |
| 509 | assert(current > matchIndex); |
| 510 | |
| 511 | if ((!extDict) || (matchIndex+matchLength >= dictLimit)) { |
| 512 | assert(matchIndex+matchLength >= dictLimit); /* ensure the condition is correct when !extDict */ |
| 513 | match = base + matchIndex; |
| 514 | matchLength += ZSTD_count(ip+matchLength, match+matchLength, iLimit); |
| 515 | } else { |
| 516 | match = dictBase + matchIndex; |
| 517 | matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iLimit, dictEnd, prefixStart); |
| 518 | if (matchIndex+matchLength >= dictLimit) |
| 519 | match = base + matchIndex; /* prepare for match[matchLength] */ |
| 520 | } |
| 521 | |
| 522 | if (matchLength > bestLength) { |
| 523 | DEBUGLOG(8, "found match of length %u at distance %u", |
| 524 | (U32)matchLength, current - matchIndex); |
| 525 | assert(matchEndIdx > matchIndex); |
| 526 | if (matchLength > matchEndIdx - matchIndex) |
| 527 | matchEndIdx = matchIndex + (U32)matchLength; |
| 528 | bestLength = matchLength; |
| 529 | matches[mnum].off = (current - matchIndex) + ZSTD_REP_MOVE; |
| 530 | matches[mnum].len = (U32)matchLength; |
| 531 | mnum++; |
| 532 | if (matchLength > ZSTD_OPT_NUM) break; |
| 533 | if (ip+matchLength == iLimit) { /* equal : no way to know if inf or sup */ |
| 534 | break; /* drop, to preserve bt consistency (miss a little bit of compression) */ |
| 535 | } |
| 536 | } |
| 537 | |
| 538 | if (match[matchLength] < ip[matchLength]) { |
| 539 | /* match smaller than current */ |
| 540 | *smallerPtr = matchIndex; /* update smaller idx */ |
| 541 | commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */ |
| 542 | if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */ |
| 543 | smallerPtr = nextPtr+1; /* new candidate => larger than match, which was smaller than current */ |
| 544 | matchIndex = nextPtr[1]; /* new matchIndex, larger than previous, closer to current */ |
| 545 | } else { |
| 546 | *largerPtr = matchIndex; |
| 547 | commonLengthLarger = matchLength; |
| 548 | if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */ |
| 549 | largerPtr = nextPtr; |
| 550 | matchIndex = nextPtr[0]; |
| 551 | } } |
| 552 | |
| 553 | *smallerPtr = *largerPtr = 0; |
| 554 | |
| 555 | assert(matchEndIdx > current+8); |
| 556 | ms->nextToUpdate = matchEndIdx - 8; /* skip repetitive patterns */ |
| 557 | return mnum; |
| 558 | } |
| 559 | |
| 560 | |
| 561 | FORCE_INLINE_TEMPLATE U32 ZSTD_BtGetAllMatches ( |
| 562 | ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams, |
| 563 | const BYTE* ip, const BYTE* const iHighLimit, int const extDict, |
| 564 | U32 rep[ZSTD_REP_NUM], U32 const ll0, |
| 565 | ZSTD_match_t* matches, U32 const lengthToBeat) |
| 566 | { |
| 567 | U32 const matchLengthSearch = cParams->searchLength; |
| 568 | DEBUGLOG(7, "ZSTD_BtGetAllMatches"); |
| 569 | if (ip < ms->window.base + ms->nextToUpdate) return 0; /* skipped area */ |
| 570 | ZSTD_updateTree_internal(ms, cParams, ip, iHighLimit, matchLengthSearch, extDict); |
| 571 | switch(matchLengthSearch) |
| 572 | { |
| 573 | case 3 : return ZSTD_insertBtAndGetAllMatches(ms, cParams, ip, iHighLimit, extDict, rep, ll0, matches, lengthToBeat, 3); |
| 574 | default : |
| 575 | case 4 : return ZSTD_insertBtAndGetAllMatches(ms, cParams, ip, iHighLimit, extDict, rep, ll0, matches, lengthToBeat, 4); |
| 576 | case 5 : return ZSTD_insertBtAndGetAllMatches(ms, cParams, ip, iHighLimit, extDict, rep, ll0, matches, lengthToBeat, 5); |
| 577 | case 7 : |
| 578 | case 6 : return ZSTD_insertBtAndGetAllMatches(ms, cParams, ip, iHighLimit, extDict, rep, ll0, matches, lengthToBeat, 6); |
| 579 | } |
| 580 | } |
| 581 | |
| 582 | |
| 583 | /*-******************************* |
| 584 | * Optimal parser |
| 585 | *********************************/ |
| 586 | typedef struct repcodes_s { |
| 587 | U32 rep[3]; |
| 588 | } repcodes_t; |
| 589 | |
| 590 | repcodes_t ZSTD_updateRep(U32 const rep[3], U32 const offset, U32 const ll0) |
| 591 | { |
| 592 | repcodes_t newReps; |
| 593 | if (offset >= ZSTD_REP_NUM) { /* full offset */ |
| 594 | newReps.rep[2] = rep[1]; |
| 595 | newReps.rep[1] = rep[0]; |
| 596 | newReps.rep[0] = offset - ZSTD_REP_MOVE; |
| 597 | } else { /* repcode */ |
| 598 | U32 const repCode = offset + ll0; |
| 599 | if (repCode > 0) { /* note : if repCode==0, no change */ |
| 600 | U32 const currentOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode]; |
| 601 | newReps.rep[2] = (repCode >= 2) ? rep[1] : rep[2]; |
| 602 | newReps.rep[1] = rep[0]; |
| 603 | newReps.rep[0] = currentOffset; |
| 604 | } else { /* repCode == 0 */ |
| 605 | memcpy(&newReps, rep, sizeof(newReps)); |
| 606 | } |
| 607 | } |
| 608 | return newReps; |
| 609 | } |
| 610 | |
| 611 | |
| 612 | typedef struct { |
| 613 | const BYTE* anchor; |
| 614 | U32 litlen; |
| 615 | U32 rawLitCost; |
| 616 | } cachedLiteralPrice_t; |
| 617 | |
| 618 | static U32 ZSTD_rawLiteralsCost_cached( |
| 619 | cachedLiteralPrice_t* const cachedLitPrice, |
| 620 | const BYTE* const anchor, U32 const litlen, |
| 621 | const optState_t* const optStatePtr) |
| 622 | { |
| 623 | U32 startCost; |
| 624 | U32 remainingLength; |
| 625 | const BYTE* startPosition; |
| 626 | |
| 627 | if (anchor == cachedLitPrice->anchor) { |
| 628 | startCost = cachedLitPrice->rawLitCost; |
| 629 | startPosition = anchor + cachedLitPrice->litlen; |
| 630 | assert(litlen >= cachedLitPrice->litlen); |
| 631 | remainingLength = litlen - cachedLitPrice->litlen; |
| 632 | } else { |
| 633 | startCost = 0; |
| 634 | startPosition = anchor; |
| 635 | remainingLength = litlen; |
| 636 | } |
| 637 | |
| 638 | { U32 const rawLitCost = startCost + ZSTD_rawLiteralsCost(startPosition, remainingLength, optStatePtr); |
| 639 | cachedLitPrice->anchor = anchor; |
| 640 | cachedLitPrice->litlen = litlen; |
| 641 | cachedLitPrice->rawLitCost = rawLitCost; |
| 642 | return rawLitCost; |
| 643 | } |
| 644 | } |
| 645 | |
| 646 | static U32 ZSTD_fullLiteralsCost_cached( |
| 647 | cachedLiteralPrice_t* const cachedLitPrice, |
| 648 | const BYTE* const anchor, U32 const litlen, |
| 649 | const optState_t* const optStatePtr) |
| 650 | { |
| 651 | return ZSTD_rawLiteralsCost_cached(cachedLitPrice, anchor, litlen, optStatePtr) |
| 652 | + ZSTD_litLengthPrice(litlen, optStatePtr); |
| 653 | } |
| 654 | |
| 655 | static int ZSTD_literalsContribution_cached( |
| 656 | cachedLiteralPrice_t* const cachedLitPrice, |
| 657 | const BYTE* const anchor, U32 const litlen, |
| 658 | const optState_t* const optStatePtr) |
| 659 | { |
| 660 | int const contribution = ZSTD_rawLiteralsCost_cached(cachedLitPrice, anchor, litlen, optStatePtr) |
| 661 | + ZSTD_litLengthContribution(litlen, optStatePtr); |
| 662 | return contribution; |
| 663 | } |
| 664 | |
| 665 | FORCE_INLINE_TEMPLATE |
| 666 | size_t ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,seqStore_t* seqStore, |
| 667 | U32 rep[ZSTD_REP_NUM], |
| 668 | ZSTD_compressionParameters const* cParams, |
| 669 | const void* src, size_t srcSize, |
| 670 | const int optLevel, const int extDict) |
| 671 | { |
| 672 | optState_t* const optStatePtr = &ms->opt; |
| 673 | const BYTE* const istart = (const BYTE*)src; |
| 674 | const BYTE* ip = istart; |
| 675 | const BYTE* anchor = istart; |
| 676 | const BYTE* const iend = istart + srcSize; |
| 677 | const BYTE* const ilimit = iend - 8; |
| 678 | const BYTE* const base = ms->window.base; |
| 679 | const BYTE* const prefixStart = base + ms->window.dictLimit; |
| 680 | |
| 681 | U32 const sufficient_len = MIN(cParams->targetLength, ZSTD_OPT_NUM -1); |
| 682 | U32 const minMatch = (cParams->searchLength == 3) ? 3 : 4; |
| 683 | |
| 684 | ZSTD_optimal_t* const opt = optStatePtr->priceTable; |
| 685 | ZSTD_match_t* const matches = optStatePtr->matchTable; |
| 686 | cachedLiteralPrice_t cachedLitPrice; |
| 687 | |
| 688 | /* init */ |
| 689 | DEBUGLOG(5, "ZSTD_compressBlock_opt_generic"); |
| 690 | ms->nextToUpdate3 = ms->nextToUpdate; |
| 691 | ZSTD_rescaleFreqs(optStatePtr, (const BYTE*)src, srcSize); |
| 692 | ip += (ip==prefixStart); |
| 693 | memset(&cachedLitPrice, 0, sizeof(cachedLitPrice)); |
| 694 | |
| 695 | /* Match Loop */ |
| 696 | while (ip < ilimit) { |
| 697 | U32 cur, last_pos = 0; |
| 698 | U32 best_mlen, best_off; |
| 699 | |
| 700 | /* find first match */ |
| 701 | { U32 const litlen = (U32)(ip - anchor); |
| 702 | U32 const ll0 = !litlen; |
| 703 | U32 const nbMatches = ZSTD_BtGetAllMatches(ms, cParams, ip, iend, extDict, rep, ll0, matches, minMatch); |
| 704 | if (!nbMatches) { ip++; continue; } |
| 705 | |
| 706 | /* initialize opt[0] */ |
| 707 | { U32 i ; for (i=0; i<ZSTD_REP_NUM; i++) opt[0].rep[i] = rep[i]; } |
| 708 | opt[0].mlen = 1; |
| 709 | opt[0].litlen = litlen; |
| 710 | |
| 711 | /* large match -> immediate encoding */ |
| 712 | { U32 const maxML = matches[nbMatches-1].len; |
| 713 | DEBUGLOG(7, "found %u matches of maxLength=%u and offset=%u at cPos=%u => start new serie", |
| 714 | nbMatches, maxML, matches[nbMatches-1].off, (U32)(ip-prefixStart)); |
| 715 | |
| 716 | if (maxML > sufficient_len) { |
| 717 | best_mlen = maxML; |
| 718 | best_off = matches[nbMatches-1].off; |
| 719 | DEBUGLOG(7, "large match (%u>%u), immediate encoding", |
| 720 | best_mlen, sufficient_len); |
| 721 | cur = 0; |
| 722 | last_pos = 1; |
| 723 | goto _shortestPath; |
| 724 | } } |
| 725 | |
| 726 | /* set prices for first matches starting position == 0 */ |
| 727 | { U32 const literalsPrice = ZSTD_fullLiteralsCost_cached(&cachedLitPrice, anchor, litlen, optStatePtr); |
| 728 | U32 pos; |
| 729 | U32 matchNb; |
| 730 | for (pos = 0; pos < minMatch; pos++) { |
| 731 | opt[pos].mlen = 1; |
| 732 | opt[pos].price = ZSTD_MAX_PRICE; |
| 733 | } |
| 734 | for (matchNb = 0; matchNb < nbMatches; matchNb++) { |
| 735 | U32 const offset = matches[matchNb].off; |
| 736 | U32 const end = matches[matchNb].len; |
| 737 | repcodes_t const repHistory = ZSTD_updateRep(rep, offset, ll0); |
| 738 | for ( ; pos <= end ; pos++ ) { |
| 739 | U32 const matchPrice = literalsPrice + ZSTD_getMatchPrice(offset, pos, optStatePtr, optLevel); |
| 740 | DEBUGLOG(7, "rPos:%u => set initial price : %u", |
| 741 | pos, matchPrice); |
| 742 | opt[pos].mlen = pos; |
| 743 | opt[pos].off = offset; |
| 744 | opt[pos].litlen = litlen; |
| 745 | opt[pos].price = matchPrice; |
| 746 | memcpy(opt[pos].rep, &repHistory, sizeof(repHistory)); |
| 747 | } } |
| 748 | last_pos = pos-1; |
| 749 | } |
| 750 | } |
| 751 | |
| 752 | /* check further positions */ |
| 753 | for (cur = 1; cur <= last_pos; cur++) { |
| 754 | const BYTE* const inr = ip + cur; |
| 755 | assert(cur < ZSTD_OPT_NUM); |
| 756 | |
| 757 | /* Fix current position with one literal if cheaper */ |
| 758 | { U32 const litlen = (opt[cur-1].mlen == 1) ? opt[cur-1].litlen + 1 : 1; |
| 759 | int price; /* note : contribution can be negative */ |
| 760 | if (cur > litlen) { |
| 761 | price = opt[cur - litlen].price + ZSTD_literalsContribution(inr-litlen, litlen, optStatePtr); |
| 762 | } else { |
| 763 | price = ZSTD_literalsContribution_cached(&cachedLitPrice, anchor, litlen, optStatePtr); |
| 764 | } |
| 765 | assert(price < 1000000000); /* overflow check */ |
| 766 | if (price <= opt[cur].price) { |
| 767 | DEBUGLOG(7, "rPos:%u : better price (%u<%u) using literal", |
| 768 | cur, price, opt[cur].price); |
| 769 | opt[cur].mlen = 1; |
| 770 | opt[cur].off = 0; |
| 771 | opt[cur].litlen = litlen; |
| 772 | opt[cur].price = price; |
| 773 | memcpy(opt[cur].rep, opt[cur-1].rep, sizeof(opt[cur].rep)); |
| 774 | } } |
| 775 | |
| 776 | /* last match must start at a minimum distance of 8 from oend */ |
| 777 | if (inr > ilimit) continue; |
| 778 | |
| 779 | if (cur == last_pos) break; |
| 780 | |
| 781 | if ( (optLevel==0) /*static*/ |
| 782 | && (opt[cur+1].price <= opt[cur].price) ) |
| 783 | continue; /* skip unpromising positions; about ~+6% speed, -0.01 ratio */ |
| 784 | |
| 785 | { U32 const ll0 = (opt[cur].mlen != 1); |
| 786 | U32 const litlen = (opt[cur].mlen == 1) ? opt[cur].litlen : 0; |
| 787 | U32 const previousPrice = (cur > litlen) ? opt[cur-litlen].price : 0; |
| 788 | U32 const basePrice = previousPrice + ZSTD_fullLiteralsCost(inr-litlen, litlen, optStatePtr); |
| 789 | U32 const nbMatches = ZSTD_BtGetAllMatches(ms, cParams, inr, iend, extDict, opt[cur].rep, ll0, matches, minMatch); |
| 790 | U32 matchNb; |
| 791 | if (!nbMatches) continue; |
| 792 | |
| 793 | { U32 const maxML = matches[nbMatches-1].len; |
| 794 | DEBUGLOG(7, "rPos:%u, found %u matches, of maxLength=%u", |
| 795 | cur, nbMatches, maxML); |
| 796 | |
| 797 | if ( (maxML > sufficient_len) |
| 798 | | (cur + maxML >= ZSTD_OPT_NUM) ) { |
| 799 | best_mlen = maxML; |
| 800 | best_off = matches[nbMatches-1].off; |
| 801 | last_pos = cur + 1; |
| 802 | goto _shortestPath; |
| 803 | } |
| 804 | } |
| 805 | |
| 806 | /* set prices using matches found at position == cur */ |
| 807 | for (matchNb = 0; matchNb < nbMatches; matchNb++) { |
| 808 | U32 const offset = matches[matchNb].off; |
| 809 | repcodes_t const repHistory = ZSTD_updateRep(opt[cur].rep, offset, ll0); |
| 810 | U32 const lastML = matches[matchNb].len; |
| 811 | U32 const startML = (matchNb>0) ? matches[matchNb-1].len+1 : minMatch; |
| 812 | U32 mlen; |
| 813 | |
| 814 | DEBUGLOG(7, "testing match %u => offCode=%u, mlen=%u, llen=%u", |
| 815 | matchNb, matches[matchNb].off, lastML, litlen); |
| 816 | |
| 817 | for (mlen = lastML; mlen >= startML; mlen--) { |
| 818 | U32 const pos = cur + mlen; |
| 819 | int const price = basePrice + ZSTD_getMatchPrice(offset, mlen, optStatePtr, optLevel); |
| 820 | |
| 821 | if ((pos > last_pos) || (price < opt[pos].price)) { |
| 822 | DEBUGLOG(7, "rPos:%u => new better price (%u<%u)", |
| 823 | pos, price, opt[pos].price); |
| 824 | while (last_pos < pos) { opt[last_pos+1].price = ZSTD_MAX_PRICE; last_pos++; } |
| 825 | opt[pos].mlen = mlen; |
| 826 | opt[pos].off = offset; |
| 827 | opt[pos].litlen = litlen; |
| 828 | opt[pos].price = price; |
| 829 | memcpy(opt[pos].rep, &repHistory, sizeof(repHistory)); |
| 830 | } else { |
| 831 | if (optLevel==0) break; /* gets ~+10% speed for about -0.01 ratio loss */ |
| 832 | } |
| 833 | } } } |
| 834 | } /* for (cur = 1; cur <= last_pos; cur++) */ |
| 835 | |
| 836 | best_mlen = opt[last_pos].mlen; |
| 837 | best_off = opt[last_pos].off; |
| 838 | cur = last_pos - best_mlen; |
| 839 | |
| 840 | _shortestPath: /* cur, last_pos, best_mlen, best_off have to be set */ |
| 841 | assert(opt[0].mlen == 1); |
| 842 | |
| 843 | /* reverse traversal */ |
| 844 | DEBUGLOG(7, "start reverse traversal (last_pos:%u, cur:%u)", |
| 845 | last_pos, cur); |
| 846 | { U32 selectedMatchLength = best_mlen; |
| 847 | U32 selectedOffset = best_off; |
| 848 | U32 pos = cur; |
| 849 | while (1) { |
| 850 | U32 const mlen = opt[pos].mlen; |
| 851 | U32 const off = opt[pos].off; |
| 852 | opt[pos].mlen = selectedMatchLength; |
| 853 | opt[pos].off = selectedOffset; |
| 854 | selectedMatchLength = mlen; |
| 855 | selectedOffset = off; |
| 856 | if (mlen > pos) break; |
| 857 | pos -= mlen; |
| 858 | } } |
| 859 | |
| 860 | /* save sequences */ |
| 861 | { U32 pos; |
| 862 | for (pos=0; pos < last_pos; ) { |
| 863 | U32 const llen = (U32)(ip - anchor); |
| 864 | U32 const mlen = opt[pos].mlen; |
| 865 | U32 const offset = opt[pos].off; |
| 866 | if (mlen == 1) { ip++; pos++; continue; } /* literal position => move on */ |
| 867 | pos += mlen; ip += mlen; |
| 868 | |
| 869 | /* repcodes update : like ZSTD_updateRep(), but update in place */ |
| 870 | if (offset >= ZSTD_REP_NUM) { /* full offset */ |
| 871 | rep[2] = rep[1]; |
| 872 | rep[1] = rep[0]; |
| 873 | rep[0] = offset - ZSTD_REP_MOVE; |
| 874 | } else { /* repcode */ |
| 875 | U32 const repCode = offset + (llen==0); |
| 876 | if (repCode) { /* note : if repCode==0, no change */ |
| 877 | U32 const currentOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode]; |
| 878 | if (repCode >= 2) rep[2] = rep[1]; |
| 879 | rep[1] = rep[0]; |
| 880 | rep[0] = currentOffset; |
| 881 | } |
| 882 | } |
| 883 | |
| 884 | ZSTD_updateStats(optStatePtr, llen, anchor, offset, mlen); |
| 885 | ZSTD_storeSeq(seqStore, llen, anchor, offset, mlen-MINMATCH); |
| 886 | anchor = ip; |
| 887 | } } |
| 888 | ZSTD_setLog2Prices(optStatePtr); |
| 889 | } /* while (ip < ilimit) */ |
| 890 | |
| 891 | /* Return the last literals size */ |
| 892 | return iend - anchor; |
| 893 | } |
| 894 | |
| 895 | |
| 896 | size_t ZSTD_compressBlock_btopt( |
| 897 | ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], |
| 898 | ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize) |
| 899 | { |
| 900 | DEBUGLOG(5, "ZSTD_compressBlock_btopt"); |
| 901 | return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, cParams, src, srcSize, 0 /*optLevel*/, 0 /*extDict*/); |
| 902 | } |
| 903 | |
| 904 | size_t ZSTD_compressBlock_btultra( |
| 905 | ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], |
| 906 | ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize) |
| 907 | { |
| 908 | return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, cParams, src, srcSize, 2 /*optLevel*/, 0 /*extDict*/); |
| 909 | } |
| 910 | |
| 911 | size_t ZSTD_compressBlock_btopt_extDict( |
| 912 | ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], |
| 913 | ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize) |
| 914 | { |
| 915 | return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, cParams, src, srcSize, 0 /*optLevel*/, 1 /*extDict*/); |
| 916 | } |
| 917 | |
| 918 | size_t ZSTD_compressBlock_btultra_extDict( |
| 919 | ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], |
| 920 | ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize) |
| 921 | { |
| 922 | return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, cParams, src, srcSize, 2 /*optLevel*/, 1 /*extDict*/); |
| 923 | } |