diff options
Diffstat (limited to 'Utilities/cmzstd/lib/compress/zstd_opt.c')
| -rw-r--r-- | Utilities/cmzstd/lib/compress/zstd_opt.c | 233 |
1 files changed, 108 insertions, 125 deletions
diff --git a/Utilities/cmzstd/lib/compress/zstd_opt.c b/Utilities/cmzstd/lib/compress/zstd_opt.c index 44de6e97fd..36fff050cf 100644 --- a/Utilities/cmzstd/lib/compress/zstd_opt.c +++ b/Utilities/cmzstd/lib/compress/zstd_opt.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2016-present, Przemyslaw Skibinski, Yann Collet, Facebook, Inc. + * Copyright (c) 2016-2020, Przemyslaw Skibinski, Yann Collet, Facebook, Inc. * All rights reserved. * * This source code is licensed under both the BSD-style license (found in the @@ -64,9 +64,15 @@ MEM_STATIC double ZSTD_fCost(U32 price) } #endif +static int ZSTD_compressedLiterals(optState_t const* const optPtr) +{ + return optPtr->literalCompressionMode != ZSTD_lcm_uncompressed; +} + static void ZSTD_setBasePrices(optState_t* optPtr, int optLevel) { - optPtr->litSumBasePrice = WEIGHT(optPtr->litSum, optLevel); + if (ZSTD_compressedLiterals(optPtr)) + optPtr->litSumBasePrice = WEIGHT(optPtr->litSum, optLevel); optPtr->litLengthSumBasePrice = WEIGHT(optPtr->litLengthSum, optLevel); optPtr->matchLengthSumBasePrice = WEIGHT(optPtr->matchLengthSum, optLevel); optPtr->offCodeSumBasePrice = WEIGHT(optPtr->offCodeSum, optLevel); @@ -99,6 +105,7 @@ ZSTD_rescaleFreqs(optState_t* const optPtr, const BYTE* const src, size_t const srcSize, int const optLevel) { + int const compressedLiterals = ZSTD_compressedLiterals(optPtr); DEBUGLOG(5, "ZSTD_rescaleFreqs (srcSize=%u)", (unsigned)srcSize); optPtr->priceType = zop_dynamic; @@ -113,9 +120,10 @@ ZSTD_rescaleFreqs(optState_t* const optPtr, /* huffman table presumed generated by dictionary */ optPtr->priceType = zop_dynamic; - assert(optPtr->litFreq != NULL); - optPtr->litSum = 0; - { unsigned lit; + if (compressedLiterals) { + unsigned lit; + assert(optPtr->litFreq != NULL); + optPtr->litSum = 0; for (lit=0; lit<=MaxLit; lit++) { U32 const scaleLog = 11; /* scale to 2K */ U32 const bitCost = HUF_getNbBits(optPtr->symbolCosts->huf.CTable, lit); @@ -163,10 +171,11 @@ ZSTD_rescaleFreqs(optState_t* const optPtr, } else { /* not a dictionary */ assert(optPtr->litFreq != NULL); - { unsigned lit = MaxLit; + if (compressedLiterals) { + unsigned lit = MaxLit; HIST_count_simple(optPtr->litFreq, &lit, src, srcSize); /* use raw first block to init statistics */ + optPtr->litSum = ZSTD_downscaleStat(optPtr->litFreq, MaxLit, 1); } - optPtr->litSum = ZSTD_downscaleStat(optPtr->litFreq, MaxLit, 1); { unsigned ll; for (ll=0; ll<=MaxLL; ll++) @@ -190,7 +199,8 @@ ZSTD_rescaleFreqs(optState_t* const optPtr, } else { /* new block : re-use previous statistics, scaled down */ - optPtr->litSum = ZSTD_downscaleStat(optPtr->litFreq, MaxLit, 1); + if (compressedLiterals) + optPtr->litSum = ZSTD_downscaleStat(optPtr->litFreq, MaxLit, 1); optPtr->litLengthSum = ZSTD_downscaleStat(optPtr->litLengthFreq, MaxLL, 0); optPtr->matchLengthSum = ZSTD_downscaleStat(optPtr->matchLengthFreq, MaxML, 0); optPtr->offCodeSum = ZSTD_downscaleStat(optPtr->offCodeFreq, MaxOff, 0); @@ -207,6 +217,10 @@ static U32 ZSTD_rawLiteralsCost(const BYTE* const literals, U32 const litLength, int optLevel) { if (litLength == 0) return 0; + + if (!ZSTD_compressedLiterals(optPtr)) + return (litLength << 3) * BITCOST_MULTIPLIER; /* Uncompressed - 8 bytes per literal. */ + if (optPtr->priceType == zop_predef) return (litLength*6) * BITCOST_MULTIPLIER; /* 6 bit per literal - no statistic used */ @@ -235,40 +249,6 @@ static U32 ZSTD_litLengthPrice(U32 const litLength, const optState_t* const optP } } -/* ZSTD_litLengthContribution() : - * @return ( cost(litlength) - cost(0) ) - * this value can then be added to rawLiteralsCost() - * to provide a cost which is directly comparable to a match ending at same position */ -static int ZSTD_litLengthContribution(U32 const litLength, const optState_t* const optPtr, int optLevel) -{ - if (optPtr->priceType >= zop_predef) return WEIGHT(litLength, optLevel); - - /* dynamic statistics */ - { U32 const llCode = ZSTD_LLcode(litLength); - int const contribution = (LL_bits[llCode] * BITCOST_MULTIPLIER) - + WEIGHT(optPtr->litLengthFreq[0], optLevel) /* note: log2litLengthSum cancel out */ - - WEIGHT(optPtr->litLengthFreq[llCode], optLevel); -#if 1 - return contribution; -#else - return MAX(0, contribution); /* sometimes better, sometimes not ... */ -#endif - } -} - -/* ZSTD_literalsContribution() : - * creates a fake cost for the literals part of a sequence - * which can be compared to the ending cost of a match - * should a new match start at this position */ -static int ZSTD_literalsContribution(const BYTE* const literals, U32 const litLength, - const optState_t* const optPtr, - int optLevel) -{ - int const contribution = ZSTD_rawLiteralsCost(literals, litLength, optPtr, optLevel) - + ZSTD_litLengthContribution(litLength, optPtr, optLevel); - return contribution; -} - /* ZSTD_getMatchPrice() : * Provides the cost of the match part (offset + matchLength) of a sequence * Must be combined with ZSTD_fullLiteralsCost() to get the full cost of a sequence. @@ -310,7 +290,8 @@ static void ZSTD_updateStats(optState_t* const optPtr, U32 offsetCode, U32 matchLength) { /* literals */ - { U32 u; + if (ZSTD_compressedLiterals(optPtr)) { + U32 u; for (u=0; u < litLength; u++) optPtr->litFreq[literals[u]] += ZSTD_LITFREQ_ADD; optPtr->litSum += litLength*ZSTD_LITFREQ_ADD; @@ -357,13 +338,15 @@ MEM_STATIC U32 ZSTD_readMINMATCH(const void* memPtr, U32 length) /* Update hashTable3 up to ip (excluded) Assumption : always within prefix (i.e. not within extDict) */ -static U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_matchState_t* ms, const BYTE* const ip) +static U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_matchState_t* ms, + U32* nextToUpdate3, + const BYTE* const ip) { U32* const hashTable3 = ms->hashTable3; U32 const hashLog3 = ms->hashLog3; const BYTE* const base = ms->window.base; - U32 idx = ms->nextToUpdate3; - U32 const target = ms->nextToUpdate3 = (U32)(ip - base); + U32 idx = *nextToUpdate3; + U32 const target = (U32)(ip - base); size_t const hash3 = ZSTD_hash3Ptr(ip, hashLog3); assert(hashLog3 > 0); @@ -372,6 +355,7 @@ static U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_matchState_t* ms, const BYTE* idx++; } + *nextToUpdate3 = target; return hashTable3[hash3]; } @@ -488,9 +472,11 @@ static U32 ZSTD_insertBt1( } } *smallerPtr = *largerPtr = 0; - if (bestLength > 384) return MIN(192, (U32)(bestLength - 384)); /* speed optimization */ - assert(matchEndIdx > current + 8); - return matchEndIdx - (current + 8); + { U32 positions = 0; + if (bestLength > 384) positions = MIN(192, (U32)(bestLength - 384)); /* speed optimization */ + assert(matchEndIdx > current + 8); + return MAX(positions, matchEndIdx - (current + 8)); + } } FORCE_INLINE_TEMPLATE @@ -505,8 +491,13 @@ void ZSTD_updateTree_internal( DEBUGLOG(6, "ZSTD_updateTree_internal, from %u to %u (dictMode:%u)", idx, target, dictMode); - while(idx < target) - idx += ZSTD_insertBt1(ms, base+idx, iend, mls, dictMode == ZSTD_extDict); + while(idx < target) { + U32 const forward = ZSTD_insertBt1(ms, base+idx, iend, mls, dictMode == ZSTD_extDict); + assert(idx < (U32)(idx + forward)); + idx += forward; + } + assert((size_t)(ip - base) <= (size_t)(U32)(-1)); + assert((size_t)(iend - base) <= (size_t)(U32)(-1)); ms->nextToUpdate = target; } @@ -516,11 +507,12 @@ void ZSTD_updateTree(ZSTD_matchState_t* ms, const BYTE* ip, const BYTE* iend) { FORCE_INLINE_TEMPLATE U32 ZSTD_insertBtAndGetAllMatches ( + ZSTD_match_t* matches, /* store result (found matches) in this table (presumed large enough) */ ZSTD_matchState_t* ms, + U32* nextToUpdate3, const BYTE* const ip, const BYTE* const iLimit, const ZSTD_dictMode_e dictMode, - U32 rep[ZSTD_REP_NUM], + const U32 rep[ZSTD_REP_NUM], U32 const ll0, /* tells if associated literal length is 0 or not. This value must be 0 or 1 */ - ZSTD_match_t* matches, const U32 lengthToBeat, U32 const mls /* template */) { @@ -541,8 +533,8 @@ U32 ZSTD_insertBtAndGetAllMatches ( U32 const dictLimit = ms->window.dictLimit; const BYTE* const dictEnd = dictBase + dictLimit; const BYTE* const prefixStart = base + dictLimit; - U32 const btLow = btMask >= current ? 0 : current - btMask; - U32 const windowLow = ms->window.lowLimit; + U32 const btLow = (btMask >= current) ? 0 : current - btMask; + U32 const windowLow = ZSTD_getLowestMatchIndex(ms, current, cParams->windowLog); U32 const matchLow = windowLow ? windowLow : 1; U32* smallerPtr = bt + 2*(current&btMask); U32* largerPtr = bt + 2*(current&btMask) + 1; @@ -577,7 +569,10 @@ U32 ZSTD_insertBtAndGetAllMatches ( U32 repLen = 0; assert(current >= dictLimit); if (repOffset-1 /* intentional overflow, discards 0 and -1 */ < current-dictLimit) { /* equivalent to `current > repIndex >= dictLimit` */ - if (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(ip - repOffset, minMatch)) { + /* We must validate the repcode offset because when we're using a dictionary the + * valid offset range shrinks when the dictionary goes out of bounds. + */ + if ((repIndex >= windowLow) & (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(ip - repOffset, minMatch))) { repLen = (U32)ZSTD_count(ip+minMatch, ip+minMatch-repOffset, iLimit) + minMatch; } } else { /* repIndex < dictLimit || repIndex >= current */ @@ -612,7 +607,7 @@ U32 ZSTD_insertBtAndGetAllMatches ( /* HC3 match finder */ if ((mls == 3) /*static*/ && (bestLength < mls)) { - U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3(ms, ip); + U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3(ms, nextToUpdate3, ip); if ((matchIndex3 >= matchLow) & (current - matchIndex3 < (1<<18)) /*heuristic : longer distance likely too expensive*/ ) { size_t mlen; @@ -638,9 +633,7 @@ U32 ZSTD_insertBtAndGetAllMatches ( (ip+mlen == iLimit) ) { /* best possible length */ ms->nextToUpdate = current+1; /* skip insertion */ return 1; - } - } - } + } } } /* no dictMatchState lookup: dicts don't have a populated HC3 table */ } @@ -648,19 +641,21 @@ U32 ZSTD_insertBtAndGetAllMatches ( while (nbCompares-- && (matchIndex >= matchLow)) { U32* const nextPtr = bt + 2*(matchIndex & btMask); - size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */ const BYTE* match; + size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */ assert(current > matchIndex); if ((dictMode == ZSTD_noDict) || (dictMode == ZSTD_dictMatchState) || (matchIndex+matchLength >= dictLimit)) { assert(matchIndex+matchLength >= dictLimit); /* ensure the condition is correct when !extDict */ match = base + matchIndex; + if (matchIndex >= dictLimit) assert(memcmp(match, ip, matchLength) == 0); /* ensure early section of match is equal as expected */ matchLength += ZSTD_count(ip+matchLength, match+matchLength, iLimit); } else { match = dictBase + matchIndex; + assert(memcmp(match, ip, matchLength) == 0); /* ensure early section of match is equal as expected */ matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iLimit, dictEnd, prefixStart); if (matchIndex+matchLength >= dictLimit) - match = base + matchIndex; /* prepare for match[matchLength] */ + match = base + matchIndex; /* prepare for match[matchLength] read */ } if (matchLength > bestLength) { @@ -745,10 +740,13 @@ U32 ZSTD_insertBtAndGetAllMatches ( FORCE_INLINE_TEMPLATE U32 ZSTD_BtGetAllMatches ( + ZSTD_match_t* matches, /* store result (match found, increasing size) in this table */ ZSTD_matchState_t* ms, + U32* nextToUpdate3, const BYTE* ip, const BYTE* const iHighLimit, const ZSTD_dictMode_e dictMode, - U32 rep[ZSTD_REP_NUM], U32 const ll0, - ZSTD_match_t* matches, U32 const lengthToBeat) + const U32 rep[ZSTD_REP_NUM], + U32 const ll0, + U32 const lengthToBeat) { const ZSTD_compressionParameters* const cParams = &ms->cParams; U32 const matchLengthSearch = cParams->minMatch; @@ -757,12 +755,12 @@ FORCE_INLINE_TEMPLATE U32 ZSTD_BtGetAllMatches ( ZSTD_updateTree_internal(ms, ip, iHighLimit, matchLengthSearch, dictMode); switch(matchLengthSearch) { - case 3 : return ZSTD_insertBtAndGetAllMatches(ms, ip, iHighLimit, dictMode, rep, ll0, matches, lengthToBeat, 3); + case 3 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 3); default : - case 4 : return ZSTD_insertBtAndGetAllMatches(ms, ip, iHighLimit, dictMode, rep, ll0, matches, lengthToBeat, 4); - case 5 : return ZSTD_insertBtAndGetAllMatches(ms, ip, iHighLimit, dictMode, rep, ll0, matches, lengthToBeat, 5); + case 4 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 4); + case 5 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 5); case 7 : - case 6 : return ZSTD_insertBtAndGetAllMatches(ms, ip, iHighLimit, dictMode, rep, ll0, matches, lengthToBeat, 6); + case 6 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 6); } } @@ -770,30 +768,6 @@ FORCE_INLINE_TEMPLATE U32 ZSTD_BtGetAllMatches ( /*-******************************* * Optimal parser *********************************/ -typedef struct repcodes_s { - U32 rep[3]; -} repcodes_t; - -static repcodes_t ZSTD_updateRep(U32 const rep[3], U32 const offset, U32 const ll0) -{ - repcodes_t newReps; - if (offset >= ZSTD_REP_NUM) { /* full offset */ - newReps.rep[2] = rep[1]; - newReps.rep[1] = rep[0]; - newReps.rep[0] = offset - ZSTD_REP_MOVE; - } else { /* repcode */ - U32 const repCode = offset + ll0; - if (repCode > 0) { /* note : if repCode==0, no change */ - U32 const currentOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode]; - newReps.rep[2] = (repCode >= 2) ? rep[1] : rep[2]; - newReps.rep[1] = rep[0]; - newReps.rep[0] = currentOffset; - } else { /* repCode == 0 */ - memcpy(&newReps, rep, sizeof(newReps)); - } - } - return newReps; -} static U32 ZSTD_totalLen(ZSTD_optimal_t sol) @@ -810,7 +784,7 @@ listStats(const U32* table, int lastEltID) int enb; for (enb=0; enb < nbElts; enb++) { (void)table; - //RAWLOG(2, "%3i:%3i, ", enb, table[enb]); + /* RAWLOG(2, "%3i:%3i, ", enb, table[enb]); */ RAWLOG(2, "%4i,", table[enb]); } RAWLOG(2, " \n"); @@ -838,6 +812,7 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms, U32 const sufficient_len = MIN(cParams->targetLength, ZSTD_OPT_NUM -1); U32 const minMatch = (cParams->minMatch == 3) ? 3 : 4; + U32 nextToUpdate3 = ms->nextToUpdate; ZSTD_optimal_t* const opt = optStatePtr->priceTable; ZSTD_match_t* const matches = optStatePtr->matchTable; @@ -847,7 +822,6 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms, DEBUGLOG(5, "ZSTD_compressBlock_opt_generic: current=%u, prefix=%u, nextToUpdate=%u", (U32)(ip - base), ms->window.dictLimit, ms->nextToUpdate); assert(optLevel <= 2); - ms->nextToUpdate3 = ms->nextToUpdate; ZSTD_rescaleFreqs(optStatePtr, (const BYTE*)src, srcSize, optLevel); ip += (ip==prefixStart); @@ -858,19 +832,24 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms, /* find first match */ { U32 const litlen = (U32)(ip - anchor); U32 const ll0 = !litlen; - U32 const nbMatches = ZSTD_BtGetAllMatches(ms, ip, iend, dictMode, rep, ll0, matches, minMatch); + U32 const nbMatches = ZSTD_BtGetAllMatches(matches, ms, &nextToUpdate3, ip, iend, dictMode, rep, ll0, minMatch); if (!nbMatches) { ip++; continue; } /* initialize opt[0] */ { U32 i ; for (i=0; i<ZSTD_REP_NUM; i++) opt[0].rep[i] = rep[i]; } opt[0].mlen = 0; /* means is_a_literal */ opt[0].litlen = litlen; - opt[0].price = ZSTD_literalsContribution(anchor, litlen, optStatePtr, optLevel); + /* We don't need to include the actual price of the literals because + * it is static for the duration of the forward pass, and is included + * in every price. We include the literal length to avoid negative + * prices when we subtract the previous literal length. + */ + opt[0].price = ZSTD_litLengthPrice(litlen, optStatePtr, optLevel); /* large match -> immediate encoding */ { U32 const maxML = matches[nbMatches-1].len; U32 const maxOffset = matches[nbMatches-1].off; - DEBUGLOG(6, "found %u matches of maxLength=%u and maxOffCode=%u at cPos=%u => start new serie", + DEBUGLOG(6, "found %u matches of maxLength=%u and maxOffCode=%u at cPos=%u => start new series", nbMatches, maxML, maxOffset, (U32)(ip-prefixStart)); if (maxML > sufficient_len) { @@ -894,7 +873,6 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms, for (matchNb = 0; matchNb < nbMatches; matchNb++) { U32 const offset = matches[matchNb].off; U32 const end = matches[matchNb].len; - repcodes_t const repHistory = ZSTD_updateRep(rep, offset, ll0); for ( ; pos <= end ; pos++ ) { U32 const matchPrice = ZSTD_getMatchPrice(offset, pos, optStatePtr, optLevel); U32 const sequencePrice = literalsPrice + matchPrice; @@ -904,8 +882,6 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms, opt[pos].off = offset; opt[pos].litlen = litlen; opt[pos].price = sequencePrice; - ZSTD_STATIC_ASSERT(sizeof(opt[pos].rep) == sizeof(repHistory)); - memcpy(opt[pos].rep, &repHistory, sizeof(repHistory)); } } last_pos = pos-1; } @@ -932,7 +908,6 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms, opt[cur].off = 0; opt[cur].litlen = litlen; opt[cur].price = price; - memcpy(opt[cur].rep, opt[cur-1].rep, sizeof(opt[cur].rep)); } else { DEBUGLOG(7, "cPos:%zi==rPos:%u : literal would cost more (%.2f>%.2f) (hist:%u,%u,%u)", inr-istart, cur, ZSTD_fCost(price), ZSTD_fCost(opt[cur].price), @@ -940,6 +915,21 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms, } } + /* Set the repcodes of the current position. We must do it here + * because we rely on the repcodes of the 2nd to last sequence being + * correct to set the next chunks repcodes during the backward + * traversal. + */ + ZSTD_STATIC_ASSERT(sizeof(opt[cur].rep) == sizeof(repcodes_t)); + assert(cur >= opt[cur].mlen); + if (opt[cur].mlen != 0) { + U32 const prev = cur - opt[cur].mlen; + repcodes_t newReps = ZSTD_updateRep(opt[prev].rep, opt[cur].off, opt[cur].litlen==0); + memcpy(opt[cur].rep, &newReps, sizeof(repcodes_t)); + } else { + memcpy(opt[cur].rep, opt[cur - 1].rep, sizeof(repcodes_t)); + } + /* last match must start at a minimum distance of 8 from oend */ if (inr > ilimit) continue; @@ -955,7 +945,7 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms, U32 const litlen = (opt[cur].mlen == 0) ? opt[cur].litlen : 0; U32 const previousPrice = opt[cur].price; U32 const basePrice = previousPrice + ZSTD_litLengthPrice(0, optStatePtr, optLevel); - U32 const nbMatches = ZSTD_BtGetAllMatches(ms, inr, iend, dictMode, opt[cur].rep, ll0, matches, minMatch); + U32 const nbMatches = ZSTD_BtGetAllMatches(matches, ms, &nextToUpdate3, inr, iend, dictMode, opt[cur].rep, ll0, minMatch); U32 matchNb; if (!nbMatches) { DEBUGLOG(7, "rPos:%u : no match found", cur); @@ -980,7 +970,6 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms, /* set prices using matches found at position == cur */ for (matchNb = 0; matchNb < nbMatches; matchNb++) { U32 const offset = matches[matchNb].off; - repcodes_t const repHistory = ZSTD_updateRep(opt[cur].rep, offset, ll0); U32 const lastML = matches[matchNb].len; U32 const startML = (matchNb>0) ? matches[matchNb-1].len+1 : minMatch; U32 mlen; @@ -1000,8 +989,6 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms, opt[pos].off = offset; opt[pos].litlen = litlen; opt[pos].price = price; - ZSTD_STATIC_ASSERT(sizeof(opt[pos].rep) == sizeof(repHistory)); - memcpy(opt[pos].rep, &repHistory, sizeof(repHistory)); } else { DEBUGLOG(7, "rPos:%u (ml=%2u) => new price is worse (%.2f>=%.2f)", pos, mlen, ZSTD_fCost(price), ZSTD_fCost(opt[pos].price)); @@ -1017,6 +1004,17 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms, _shortestPath: /* cur, last_pos, best_mlen, best_off have to be set */ assert(opt[0].mlen == 0); + /* Set the next chunk's repcodes based on the repcodes of the beginning + * of the last match, and the last sequence. This avoids us having to + * update them while traversing the sequences. + */ + if (lastSequence.mlen != 0) { + repcodes_t reps = ZSTD_updateRep(opt[cur].rep, lastSequence.off, lastSequence.litlen==0); + memcpy(rep, &reps, sizeof(reps)); + } else { + memcpy(rep, opt[cur].rep, sizeof(repcodes_t)); + } + { U32 const storeEnd = cur + 1; U32 storeStart = storeEnd; U32 seqPos = cur; @@ -1053,33 +1051,18 @@ _shortestPath: /* cur, last_pos, best_mlen, best_off have to be set */ continue; /* will finish */ } - /* repcodes update : like ZSTD_updateRep(), but update in place */ - if (offCode >= ZSTD_REP_NUM) { /* full offset */ - rep[2] = rep[1]; - rep[1] = rep[0]; - rep[0] = offCode - ZSTD_REP_MOVE; - } else { /* repcode */ - U32 const repCode = offCode + (llen==0); - if (repCode) { /* note : if repCode==0, no change */ - U32 const currentOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode]; - if (repCode >= 2) rep[2] = rep[1]; - rep[1] = rep[0]; - rep[0] = currentOffset; - } } - assert(anchor + llen <= iend); ZSTD_updateStats(optStatePtr, llen, anchor, offCode, mlen); - ZSTD_storeSeq(seqStore, llen, anchor, offCode, mlen-MINMATCH); + ZSTD_storeSeq(seqStore, llen, anchor, iend, offCode, mlen-MINMATCH); anchor += advance; ip = anchor; } } ZSTD_setBasePrices(optStatePtr, optLevel); } - } /* while (ip < ilimit) */ /* Return the last literals size */ - return iend - anchor; + return (size_t)(iend - anchor); } @@ -1108,7 +1091,8 @@ static U32 ZSTD_upscaleStat(unsigned* table, U32 lastEltIndex, int bonus) /* used in 2-pass strategy */ MEM_STATIC void ZSTD_upscaleStats(optState_t* optPtr) { - optPtr->litSum = ZSTD_upscaleStat(optPtr->litFreq, MaxLit, 0); + if (ZSTD_compressedLiterals(optPtr)) + optPtr->litSum = ZSTD_upscaleStat(optPtr->litFreq, MaxLit, 0); optPtr->litLengthSum = ZSTD_upscaleStat(optPtr->litLengthFreq, MaxLL, 0); optPtr->matchLengthSum = ZSTD_upscaleStat(optPtr->matchLengthFreq, MaxML, 0); optPtr->offCodeSum = ZSTD_upscaleStat(optPtr->offCodeFreq, MaxOff, 0); @@ -1117,7 +1101,7 @@ MEM_STATIC void ZSTD_upscaleStats(optState_t* optPtr) /* ZSTD_initStats_ultra(): * make a first compression pass, just to seed stats with more accurate starting values. * only works on first block, with no dictionary and no ldm. - * this function cannot error, hence its constract must be respected. + * this function cannot error, hence its contract must be respected. */ static void ZSTD_initStats_ultra(ZSTD_matchState_t* ms, @@ -1142,7 +1126,6 @@ ZSTD_initStats_ultra(ZSTD_matchState_t* ms, ms->window.dictLimit += (U32)srcSize; ms->window.lowLimit = ms->window.dictLimit; ms->nextToUpdate = ms->window.dictLimit; - ms->nextToUpdate3 = ms->window.dictLimit; /* re-inforce weight of collected statistics */ ZSTD_upscaleStats(&ms->opt); |