diff options
Diffstat (limited to 'thirdparty/zstd/compress/zstd_opt.c')
| -rw-r--r-- | thirdparty/zstd/compress/zstd_opt.c | 1180 |
1 files changed, 504 insertions, 676 deletions
diff --git a/thirdparty/zstd/compress/zstd_opt.c b/thirdparty/zstd/compress/zstd_opt.c index c47ce23ad5..7171ff5373 100644 --- a/thirdparty/zstd/compress/zstd_opt.c +++ b/thirdparty/zstd/compress/zstd_opt.c @@ -8,36 +8,35 @@ * You may select, at your option, one of the above-listed licenses. */ +#include "zstd_compress_internal.h" #include "zstd_opt.h" -#include "zstd_lazy.h" +#include "zstd_lazy.h" /* ZSTD_updateTree, ZSTD_updateTree_extDict */ -#define ZSTD_LITFREQ_ADD 2 -#define ZSTD_FREQ_DIV 4 -#define ZSTD_MAX_PRICE (1<<30) +#define ZSTD_LITFREQ_ADD 2 /* scaling factor for litFreq, so that frequencies adapt faster to new stats. Also used for matchSum (?) */ +#define ZSTD_FREQ_DIV 4 /* log factor when using previous stats to init next stats */ +#define ZSTD_MAX_PRICE (1<<30) + /*-************************************* * Price functions for optimal parser ***************************************/ static void ZSTD_setLog2Prices(optState_t* optPtr) { - optPtr->log2matchLengthSum = ZSTD_highbit32(optPtr->matchLengthSum+1); - optPtr->log2litLengthSum = ZSTD_highbit32(optPtr->litLengthSum+1); optPtr->log2litSum = ZSTD_highbit32(optPtr->litSum+1); + optPtr->log2litLengthSum = ZSTD_highbit32(optPtr->litLengthSum+1); + optPtr->log2matchLengthSum = ZSTD_highbit32(optPtr->matchLengthSum+1); optPtr->log2offCodeSum = ZSTD_highbit32(optPtr->offCodeSum+1); - optPtr->factor = 1 + ((optPtr->litSum>>5) / optPtr->litLengthSum) + ((optPtr->litSum<<1) / (optPtr->litSum + optPtr->matchSum)); } -static void ZSTD_rescaleFreqs(optState_t* optPtr, const BYTE* src, size_t srcSize) +static void ZSTD_rescaleFreqs(optState_t* const optPtr, + const BYTE* const src, size_t const srcSize) { - unsigned u; - - optPtr->cachedLiterals = NULL; - optPtr->cachedPrice = optPtr->cachedLitLength = 0; optPtr->staticPrices = 0; - if (optPtr->litLengthSum == 0) { + if (optPtr->litLengthSum == 0) { /* first init */ + unsigned u; if (srcSize <= 1024) optPtr->staticPrices = 1; assert(optPtr->litFreq!=NULL); @@ -45,44 +44,41 @@ static void ZSTD_rescaleFreqs(optState_t* optPtr, const BYTE* src, size_t srcSiz optPtr->litFreq[u] = 0; for (u=0; u<srcSize; u++) optPtr->litFreq[src[u]]++; - optPtr->litSum = 0; - optPtr->litLengthSum = MaxLL+1; - optPtr->matchLengthSum = MaxML+1; - optPtr->offCodeSum = (MaxOff+1); - optPtr->matchSum = (ZSTD_LITFREQ_ADD<<Litbits); - for (u=0; u<=MaxLit; u++) { - optPtr->litFreq[u] = 1 + (optPtr->litFreq[u]>>ZSTD_FREQ_DIV); + optPtr->litFreq[u] = 1 + (optPtr->litFreq[u] >> ZSTD_FREQ_DIV); optPtr->litSum += optPtr->litFreq[u]; } + for (u=0; u<=MaxLL; u++) optPtr->litLengthFreq[u] = 1; + optPtr->litLengthSum = MaxLL+1; for (u=0; u<=MaxML; u++) optPtr->matchLengthFreq[u] = 1; + optPtr->matchLengthSum = MaxML+1; for (u=0; u<=MaxOff; u++) optPtr->offCodeFreq[u] = 1; + optPtr->offCodeSum = (MaxOff+1); + } else { - optPtr->matchLengthSum = 0; - optPtr->litLengthSum = 0; - optPtr->offCodeSum = 0; - optPtr->matchSum = 0; - optPtr->litSum = 0; + unsigned u; + optPtr->litSum = 0; for (u=0; u<=MaxLit; u++) { - optPtr->litFreq[u] = 1 + (optPtr->litFreq[u]>>(ZSTD_FREQ_DIV+1)); + optPtr->litFreq[u] = 1 + (optPtr->litFreq[u] >> (ZSTD_FREQ_DIV+1)); optPtr->litSum += optPtr->litFreq[u]; } + optPtr->litLengthSum = 0; for (u=0; u<=MaxLL; u++) { optPtr->litLengthFreq[u] = 1 + (optPtr->litLengthFreq[u]>>(ZSTD_FREQ_DIV+1)); optPtr->litLengthSum += optPtr->litLengthFreq[u]; } + optPtr->matchLengthSum = 0; for (u=0; u<=MaxML; u++) { optPtr->matchLengthFreq[u] = 1 + (optPtr->matchLengthFreq[u]>>ZSTD_FREQ_DIV); optPtr->matchLengthSum += optPtr->matchLengthFreq[u]; - optPtr->matchSum += optPtr->matchLengthFreq[u] * (u + 3); } - optPtr->matchSum *= ZSTD_LITFREQ_ADD; + optPtr->offCodeSum = 0; for (u=0; u<=MaxOff; u++) { optPtr->offCodeFreq[u] = 1 + (optPtr->offCodeFreq[u]>>ZSTD_FREQ_DIV); optPtr->offCodeSum += optPtr->offCodeFreq[u]; @@ -93,114 +89,146 @@ static void ZSTD_rescaleFreqs(optState_t* optPtr, const BYTE* src, size_t srcSiz } -static U32 ZSTD_getLiteralPrice(optState_t* optPtr, U32 litLength, const BYTE* literals) +/* ZSTD_rawLiteralsCost() : + * cost of literals (only) in given segment (which length can be null) + * does not include cost of literalLength symbol */ +static U32 ZSTD_rawLiteralsCost(const BYTE* const literals, U32 const litLength, + const optState_t* const optPtr) { - U32 price, u; - - if (optPtr->staticPrices) - return ZSTD_highbit32((U32)litLength+1) + (litLength*6); - - if (litLength == 0) - return optPtr->log2litLengthSum - ZSTD_highbit32(optPtr->litLengthFreq[0]+1); + if (optPtr->staticPrices) return (litLength*6); /* 6 bit per literal - no statistic used */ + if (litLength == 0) return 0; /* literals */ - if (optPtr->cachedLiterals == literals) { - U32 const additional = litLength - optPtr->cachedLitLength; - const BYTE* literals2 = optPtr->cachedLiterals + optPtr->cachedLitLength; - price = optPtr->cachedPrice + additional * optPtr->log2litSum; - for (u=0; u < additional; u++) - price -= ZSTD_highbit32(optPtr->litFreq[literals2[u]]+1); - optPtr->cachedPrice = price; - optPtr->cachedLitLength = litLength; - } else { - price = litLength * optPtr->log2litSum; + { U32 u; + U32 cost = litLength * optPtr->log2litSum; for (u=0; u < litLength; u++) - price -= ZSTD_highbit32(optPtr->litFreq[literals[u]]+1); - - if (litLength >= 12) { - optPtr->cachedLiterals = literals; - optPtr->cachedPrice = price; - optPtr->cachedLitLength = litLength; - } + cost -= ZSTD_highbit32(optPtr->litFreq[literals[u]]+1); + return cost; } +} + +/* ZSTD_litLengthPrice() : + * cost of literalLength symbol */ +static U32 ZSTD_litLengthPrice(U32 const litLength, const optState_t* const optPtr) +{ + if (optPtr->staticPrices) return ZSTD_highbit32((U32)litLength+1); /* literal Length */ - { const BYTE LL_deltaCode = 19; - const BYTE llCode = (litLength>63) ? (BYTE)ZSTD_highbit32(litLength) + LL_deltaCode : LL_Code[litLength]; - price += LL_bits[llCode] + optPtr->log2litLengthSum - ZSTD_highbit32(optPtr->litLengthFreq[llCode]+1); + { U32 const llCode = ZSTD_LLcode(litLength); + U32 const price = LL_bits[llCode] + optPtr->log2litLengthSum - ZSTD_highbit32(optPtr->litLengthFreq[llCode]+1); + return price; } +} - return price; +/* ZSTD_litLengthPrice() : + * cost of the literal part of a sequence, + * including literals themselves, and literalLength symbol */ +static U32 ZSTD_fullLiteralsCost(const BYTE* const literals, U32 const litLength, + const optState_t* const optPtr) +{ + return ZSTD_rawLiteralsCost(literals, litLength, optPtr) + + ZSTD_litLengthPrice(litLength, optPtr); +} + +/* 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) +{ + if (optPtr->staticPrices) return ZSTD_highbit32(litLength+1); + + /* literal Length */ + { U32 const llCode = ZSTD_LLcode(litLength); + int const contribution = LL_bits[llCode] + + ZSTD_highbit32(optPtr->litLengthFreq[0]+1) + - ZSTD_highbit32(optPtr->litLengthFreq[llCode]+1); +#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 const contribution = ZSTD_rawLiteralsCost(literals, litLength, optPtr) + + ZSTD_litLengthContribution(litLength, optPtr); + return contribution; +} -FORCE_INLINE_TEMPLATE U32 ZSTD_getPrice(optState_t* optPtr, U32 litLength, const BYTE* literals, U32 offset, U32 matchLength, const int ultra) +/* 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. + * optLevel: when <2, favors small offset for decompression speed (improved cache efficiency) */ +FORCE_INLINE_TEMPLATE U32 ZSTD_getMatchPrice( + U32 const offset, U32 const matchLength, + const optState_t* const optPtr, + int const optLevel) { - /* offset */ U32 price; - BYTE const offCode = (BYTE)ZSTD_highbit32(offset+1); + U32 const offCode = ZSTD_highbit32(offset+1); + U32 const mlBase = matchLength - MINMATCH; + assert(matchLength >= MINMATCH); - if (optPtr->staticPrices) - return ZSTD_getLiteralPrice(optPtr, litLength, literals) + ZSTD_highbit32((U32)matchLength+1) + 16 + offCode; + if (optPtr->staticPrices) /* fixed scheme, do not use statistics */ + return ZSTD_highbit32((U32)mlBase+1) + 16 + offCode; price = offCode + optPtr->log2offCodeSum - ZSTD_highbit32(optPtr->offCodeFreq[offCode]+1); - if (!ultra && offCode >= 20) price += (offCode-19)*2; + if ((optLevel<2) /*static*/ && offCode >= 20) price += (offCode-19)*2; /* handicap for long distance offsets, favor decompression speed */ /* match Length */ - { const BYTE ML_deltaCode = 36; - const BYTE mlCode = (matchLength>127) ? (BYTE)ZSTD_highbit32(matchLength) + ML_deltaCode : ML_Code[matchLength]; + { U32 const mlCode = ZSTD_MLcode(mlBase); price += ML_bits[mlCode] + optPtr->log2matchLengthSum - ZSTD_highbit32(optPtr->matchLengthFreq[mlCode]+1); } - return price + ZSTD_getLiteralPrice(optPtr, litLength, literals) + optPtr->factor; + DEBUGLOG(8, "ZSTD_getMatchPrice(ml:%u) = %u", matchLength, price); + return price; } - -static void ZSTD_updatePrice(optState_t* optPtr, U32 litLength, const BYTE* literals, U32 offset, U32 matchLength) +static void ZSTD_updateStats(optState_t* const optPtr, + U32 litLength, const BYTE* literals, + U32 offsetCode, U32 matchLength) { - U32 u; - /* literals */ - optPtr->litSum += litLength*ZSTD_LITFREQ_ADD; - for (u=0; u < litLength; u++) - optPtr->litFreq[literals[u]] += ZSTD_LITFREQ_ADD; + { U32 u; + for (u=0; u < litLength; u++) + optPtr->litFreq[literals[u]] += ZSTD_LITFREQ_ADD; + optPtr->litSum += litLength*ZSTD_LITFREQ_ADD; + } /* literal Length */ - { const BYTE LL_deltaCode = 19; - const BYTE llCode = (litLength>63) ? (BYTE)ZSTD_highbit32(litLength) + LL_deltaCode : LL_Code[litLength]; + { U32 const llCode = ZSTD_LLcode(litLength); optPtr->litLengthFreq[llCode]++; optPtr->litLengthSum++; } - /* match offset */ - { BYTE const offCode = (BYTE)ZSTD_highbit32(offset+1); - optPtr->offCodeSum++; + /* match offset code (0-2=>repCode; 3+=>offset+2) */ + { U32 const offCode = ZSTD_highbit32(offsetCode+1); + assert(offCode <= MaxOff); optPtr->offCodeFreq[offCode]++; + optPtr->offCodeSum++; } /* match Length */ - { const BYTE ML_deltaCode = 36; - const BYTE mlCode = (matchLength>127) ? (BYTE)ZSTD_highbit32(matchLength) + ML_deltaCode : ML_Code[matchLength]; + { U32 const mlBase = matchLength - MINMATCH; + U32 const mlCode = ZSTD_MLcode(mlBase); optPtr->matchLengthFreq[mlCode]++; optPtr->matchLengthSum++; } - - ZSTD_setLog2Prices(optPtr); } -#define SET_PRICE(pos, mlen_, offset_, litlen_, price_) \ - { \ - while (last_pos < pos) { opt[last_pos+1].price = ZSTD_MAX_PRICE; last_pos++; } \ - opt[pos].mlen = mlen_; \ - opt[pos].off = offset_; \ - opt[pos].litlen = litlen_; \ - opt[pos].price = price_; \ - } - - -/* function safe only for comparisons */ -static U32 ZSTD_readMINMATCH(const void* memPtr, U32 length) +/* ZSTD_readMINMATCH() : + * function safe only for comparisons + * assumption : memPtr must be at least 4 bytes before end of buffer */ +MEM_STATIC U32 ZSTD_readMINMATCH(const void* memPtr, U32 length) { switch (length) { @@ -216,15 +244,14 @@ 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_CCtx* zc, const BYTE* ip) +static U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_CCtx* const cctx, const BYTE* const ip) { - U32* const hashTable3 = zc->hashTable3; - U32 const hashLog3 = zc->hashLog3; - const BYTE* const base = zc->base; - U32 idx = zc->nextToUpdate3; - const U32 target = zc->nextToUpdate3 = (U32)(ip - base); - const size_t hash3 = ZSTD_hash3Ptr(ip, hashLog3); + U32* const hashTable3 = cctx->hashTable3; + U32 const hashLog3 = cctx->hashLog3; + const BYTE* const base = cctx->base; + U32 idx = cctx->nextToUpdate3; + U32 const target = cctx->nextToUpdate3 = (U32)(ip - base); + size_t const hash3 = ZSTD_hash3Ptr(ip, hashLog3); while(idx < target) { hashTable3[ZSTD_hash3Ptr(base+idx, hashLog3)] = idx; @@ -238,102 +265,147 @@ U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_CCtx* zc, const BYTE* ip) /*-************************************* * Binary Tree search ***************************************/ -static U32 ZSTD_insertBtAndGetAllMatches ( - ZSTD_CCtx* zc, - const BYTE* const ip, const BYTE* const iLimit, - U32 nbCompares, const U32 mls, - U32 extDict, ZSTD_match_t* matches, const U32 minMatchLen) +FORCE_INLINE_TEMPLATE +U32 ZSTD_insertBtAndGetAllMatches ( + ZSTD_CCtx* zc, + const BYTE* const ip, const BYTE* const iLimit, int const extDict, + U32 nbCompares, U32 const mls, U32 const sufficient_len, + U32 rep[ZSTD_REP_NUM], U32 const ll0, + ZSTD_match_t* matches, const U32 lengthToBeat) { const BYTE* const base = zc->base; - const U32 current = (U32)(ip-base); - const U32 hashLog = zc->appliedParams.cParams.hashLog; - const size_t h = ZSTD_hashPtr(ip, hashLog, mls); + U32 const current = (U32)(ip-base); + U32 const hashLog = zc->appliedParams.cParams.hashLog; + U32 const minMatch = (mls==3) ? 3 : 4; U32* const hashTable = zc->hashTable; + size_t const h = ZSTD_hashPtr(ip, hashLog, mls); U32 matchIndex = hashTable[h]; U32* const bt = zc->chainTable; - const U32 btLog = zc->appliedParams.cParams.chainLog - 1; - const U32 btMask= (1U << btLog) - 1; + U32 const btLog = zc->appliedParams.cParams.chainLog - 1; + U32 const btMask= (1U << btLog) - 1; size_t commonLengthSmaller=0, commonLengthLarger=0; const BYTE* const dictBase = zc->dictBase; - const U32 dictLimit = zc->dictLimit; + U32 const dictLimit = zc->dictLimit; const BYTE* const dictEnd = dictBase + dictLimit; const BYTE* const prefixStart = base + dictLimit; - const U32 btLow = btMask >= current ? 0 : current - btMask; - const U32 windowLow = zc->lowLimit; + U32 const btLow = btMask >= current ? 0 : current - btMask; + U32 const windowLow = zc->lowLimit; U32* smallerPtr = bt + 2*(current&btMask); U32* largerPtr = bt + 2*(current&btMask) + 1; - U32 matchEndIdx = current+8; + U32 matchEndIdx = current+8+1; /* farthest referenced position of any match => detects repetitive patterns */ U32 dummy32; /* to be nullified at the end */ U32 mnum = 0; - const U32 minMatch = (mls == 3) ? 3 : 4; - size_t bestLength = minMatchLen-1; + size_t bestLength = lengthToBeat-1; + DEBUGLOG(7, "ZSTD_insertBtAndGetAllMatches"); + + /* check repCode */ + { U32 const lastR = ZSTD_REP_NUM + ll0; + U32 repCode; + for (repCode = ll0; repCode < lastR; repCode++) { + U32 const repOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode]; + U32 const repIndex = current - repOffset; + 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)) { + repLen = (U32)ZSTD_count(ip+minMatch, ip+minMatch-repOffset, iLimit) + minMatch; + } + } else { /* repIndex < dictLimit || repIndex >= current */ + const BYTE* const repMatch = dictBase + repIndex; + assert(current >= windowLow); + if ( extDict /* this case only valid in extDict mode */ + && ( ((repOffset-1) /*intentional overflow*/ < current - windowLow) /* equivalent to `current > repIndex >= windowLow` */ + & (((U32)((dictLimit-1) - repIndex) >= 3) ) /* intentional overflow : do not test positions overlapping 2 memory segments */) + && (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch)) ) { + repLen = (U32)ZSTD_count_2segments(ip+minMatch, repMatch+minMatch, iLimit, dictEnd, prefixStart) + minMatch; + } } + /* save longer solution */ + if (repLen > bestLength) { + DEBUGLOG(8, "found rep-match %u of length %u", + repCode - ll0, (U32)repLen); + bestLength = repLen; + matches[mnum].off = repCode - ll0; + matches[mnum].len = (U32)repLen; + mnum++; + if ( (repLen > sufficient_len) + | (ip+repLen == iLimit) ) { /* best possible */ + return mnum; + } } } } - if (minMatch == 3) { /* HC3 match finder */ + /* HC3 match finder */ + if ((mls == 3) /*static*/ && (bestLength < mls)) { U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3 (zc, ip); - if (matchIndex3>windowLow && (current - matchIndex3 < (1<<18))) { - const BYTE* match; - size_t currentMl=0; - if ((!extDict) || matchIndex3 >= dictLimit) { - match = base + matchIndex3; - if (match[bestLength] == ip[bestLength]) currentMl = ZSTD_count(ip, match, iLimit); + if ((matchIndex3 > windowLow) + & (current - matchIndex3 < (1<<18)) /*heuristic : longer distance likely too expensive*/ ) { + size_t mlen; + if ((!extDict) /*static*/ || (matchIndex3 >= dictLimit)) { + const BYTE* const match = base + matchIndex3; + mlen = ZSTD_count(ip, match, iLimit); } else { - match = dictBase + matchIndex3; - if (ZSTD_readMINMATCH(match, MINMATCH) == ZSTD_readMINMATCH(ip, MINMATCH)) /* assumption : matchIndex3 <= dictLimit-4 (by table construction) */ - currentMl = ZSTD_count_2segments(ip+MINMATCH, match+MINMATCH, iLimit, dictEnd, prefixStart) + MINMATCH; + const BYTE* const match = dictBase + matchIndex3; + mlen = ZSTD_count_2segments(ip, match, iLimit, dictEnd, prefixStart); } /* save best solution */ - if (currentMl > bestLength) { - bestLength = currentMl; - matches[mnum].off = ZSTD_REP_MOVE_OPT + current - matchIndex3; - matches[mnum].len = (U32)currentMl; - mnum++; - if (currentMl > ZSTD_OPT_NUM) goto update; - if (ip+currentMl == iLimit) goto update; /* best possible, and avoid read overflow*/ - } - } - } + if (mlen >= mls /* == 3 > bestLength */) { + DEBUGLOG(8, "found small match with hlog3, of length %u", + (U32)mlen); + bestLength = mlen; + assert(current > matchIndex3); + assert(mnum==0); /* no prior solution */ + matches[0].off = (current - matchIndex3) + ZSTD_REP_MOVE; + matches[0].len = (U32)mlen; + mnum = 1; + if ( (mlen > sufficient_len) | + (ip+mlen == iLimit) ) { /* best possible length */ + zc->nextToUpdate = current+1; /* skip insertion */ + return 1; + } } } } hashTable[h] = current; /* Update Hash Table */ while (nbCompares-- && (matchIndex > windowLow)) { - U32* nextPtr = bt + 2*(matchIndex & btMask); + U32* const nextPtr = bt + 2*(matchIndex & btMask); size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */ const BYTE* match; + assert(current > matchIndex); if ((!extDict) || (matchIndex+matchLength >= dictLimit)) { + assert(matchIndex+matchLength >= dictLimit); /* ensure the condition is correct when !extDict */ match = base + matchIndex; - if (match[matchLength] == ip[matchLength]) { - matchLength += ZSTD_count(ip+matchLength+1, match+matchLength+1, iLimit) +1; - } + matchLength += ZSTD_count(ip+matchLength, match+matchLength, iLimit); } else { match = dictBase + matchIndex; matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iLimit, dictEnd, prefixStart); if (matchIndex+matchLength >= dictLimit) - match = base + matchIndex; /* to prepare for next usage of match[matchLength] */ + match = base + matchIndex; /* prepare for match[matchLength] */ } if (matchLength > bestLength) { - if (matchLength > matchEndIdx - matchIndex) matchEndIdx = matchIndex + (U32)matchLength; + DEBUGLOG(8, "found match of length %u at distance %u", + (U32)matchLength, current - matchIndex); + assert(matchEndIdx > matchIndex); + if (matchLength > matchEndIdx - matchIndex) + matchEndIdx = matchIndex + (U32)matchLength; bestLength = matchLength; - matches[mnum].off = ZSTD_REP_MOVE_OPT + current - matchIndex; + matches[mnum].off = (current - matchIndex) + ZSTD_REP_MOVE; matches[mnum].len = (U32)matchLength; mnum++; if (matchLength > ZSTD_OPT_NUM) break; - if (ip+matchLength == iLimit) /* equal : no way to know if inf or sup */ - break; /* drop, to guarantee consistency (miss a little bit of compression) */ + if (ip+matchLength == iLimit) { /* equal : no way to know if inf or sup */ + break; /* drop, to preserve bt consistency (miss a little bit of compression) */ + } } if (match[matchLength] < ip[matchLength]) { - /* match is smaller than current */ + /* match smaller than current */ *smallerPtr = matchIndex; /* update smaller idx */ commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */ if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */ - smallerPtr = nextPtr+1; /* new "smaller" => larger of match */ - matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */ + smallerPtr = nextPtr+1; /* new candidate => larger than match, which was smaller than current */ + matchIndex = nextPtr[1]; /* new matchIndex, larger than previous, closer to current */ } else { - /* match is larger than current */ *largerPtr = matchIndex; commonLengthLarger = matchLength; if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */ @@ -343,65 +415,31 @@ static U32 ZSTD_insertBtAndGetAllMatches ( *smallerPtr = *largerPtr = 0; -update: - zc->nextToUpdate = (matchEndIdx > current + 8) ? matchEndIdx - 8 : current+1; + assert(matchEndIdx > current+8); + zc->nextToUpdate = matchEndIdx - 8; /* skip repetitive patterns */ return mnum; } -/** Tree updater, providing best match */ -static U32 ZSTD_BtGetAllMatches ( - ZSTD_CCtx* zc, - const BYTE* const ip, const BYTE* const iLimit, - const U32 maxNbAttempts, const U32 mls, ZSTD_match_t* matches, const U32 minMatchLen) -{ - if (ip < zc->base + zc->nextToUpdate) return 0; /* skipped area */ - ZSTD_updateTree(zc, ip, iLimit, maxNbAttempts, mls); - return ZSTD_insertBtAndGetAllMatches(zc, ip, iLimit, maxNbAttempts, mls, 0, matches, minMatchLen); -} - - -static U32 ZSTD_BtGetAllMatches_selectMLS ( +FORCE_INLINE_TEMPLATE U32 ZSTD_BtGetAllMatches ( ZSTD_CCtx* zc, /* Index table will be updated */ - const BYTE* ip, const BYTE* const iHighLimit, - const U32 maxNbAttempts, const U32 matchLengthSearch, ZSTD_match_t* matches, const U32 minMatchLen) -{ - switch(matchLengthSearch) - { - case 3 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 3, matches, minMatchLen); - default : - case 4 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 4, matches, minMatchLen); - case 5 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 5, matches, minMatchLen); - case 7 : - case 6 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 6, matches, minMatchLen); - } -} - -/** Tree updater, providing best match */ -static U32 ZSTD_BtGetAllMatches_extDict ( - ZSTD_CCtx* zc, - const BYTE* const ip, const BYTE* const iLimit, - const U32 maxNbAttempts, const U32 mls, ZSTD_match_t* matches, const U32 minMatchLen) + const BYTE* ip, const BYTE* const iHighLimit, int const extDict, + U32 const maxNbAttempts, U32 const matchLengthSearch, U32 const sufficient_len, + U32 rep[ZSTD_REP_NUM], U32 const ll0, + ZSTD_match_t* matches, U32 const lengthToBeat) { + DEBUGLOG(7, "ZSTD_BtGetAllMatches"); if (ip < zc->base + zc->nextToUpdate) return 0; /* skipped area */ - ZSTD_updateTree_extDict(zc, ip, iLimit, maxNbAttempts, mls); - return ZSTD_insertBtAndGetAllMatches(zc, ip, iLimit, maxNbAttempts, mls, 1, matches, minMatchLen); -} - - -static U32 ZSTD_BtGetAllMatches_selectMLS_extDict ( - ZSTD_CCtx* zc, /* Index table will be updated */ - const BYTE* ip, const BYTE* const iHighLimit, - const U32 maxNbAttempts, const U32 matchLengthSearch, ZSTD_match_t* matches, const U32 minMatchLen) -{ + if (extDict) ZSTD_updateTree_extDict(zc, ip, iHighLimit, maxNbAttempts, matchLengthSearch); + else ZSTD_updateTree(zc, ip, iHighLimit, maxNbAttempts, matchLengthSearch); switch(matchLengthSearch) { - case 3 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 3, matches, minMatchLen); + case 3 : return ZSTD_insertBtAndGetAllMatches(zc, ip, iHighLimit, extDict, maxNbAttempts, 3, sufficient_len, rep, ll0, matches, lengthToBeat); default : - case 4 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 4, matches, minMatchLen); - case 5 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 5, matches, minMatchLen); + case 4 : return ZSTD_insertBtAndGetAllMatches(zc, ip, iHighLimit, extDict, maxNbAttempts, 4, sufficient_len, rep, ll0, matches, lengthToBeat); + case 5 : return ZSTD_insertBtAndGetAllMatches(zc, ip, iHighLimit, extDict, maxNbAttempts, 5, sufficient_len, rep, ll0, matches, lengthToBeat); case 7 : - case 6 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 6, matches, minMatchLen); + case 6 : return ZSTD_insertBtAndGetAllMatches(zc, ip, iHighLimit, extDict, maxNbAttempts, 6, sufficient_len, rep, ll0, matches, lengthToBeat); } } @@ -409,534 +447,313 @@ static U32 ZSTD_BtGetAllMatches_selectMLS_extDict ( /*-******************************* * Optimal parser *********************************/ -FORCE_INLINE_TEMPLATE -size_t ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx, - const void* src, size_t srcSize, const int ultra) -{ - seqStore_t* seqStorePtr = &(ctx->seqStore); - optState_t* optStatePtr = &(ctx->optState); - const BYTE* const istart = (const BYTE*)src; - const BYTE* ip = istart; - const BYTE* anchor = istart; - const BYTE* const iend = istart + srcSize; - const BYTE* const ilimit = iend - 8; - const BYTE* const base = ctx->base; - const BYTE* const prefixStart = base + ctx->dictLimit; - - const U32 maxSearches = 1U << ctx->appliedParams.cParams.searchLog; - const U32 sufficient_len = ctx->appliedParams.cParams.targetLength; - const U32 mls = ctx->appliedParams.cParams.searchLength; - const U32 minMatch = (ctx->appliedParams.cParams.searchLength == 3) ? 3 : 4; - - ZSTD_optimal_t* opt = optStatePtr->priceTable; - ZSTD_match_t* matches = optStatePtr->matchTable; - const BYTE* inr; - U32 offset, rep[ZSTD_REP_NUM]; - - /* init */ - ctx->nextToUpdate3 = ctx->nextToUpdate; - ZSTD_rescaleFreqs(optStatePtr, (const BYTE*)src, srcSize); - ip += (ip==prefixStart); - { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) rep[i]=seqStorePtr->rep[i]; } - - /* Match Loop */ - while (ip < ilimit) { - U32 cur, match_num, last_pos, litlen, price; - U32 u, mlen, best_mlen, best_off, litLength; - memset(opt, 0, sizeof(ZSTD_optimal_t)); - last_pos = 0; - litlen = (U32)(ip - anchor); - - /* check repCode */ - { U32 i, last_i = ZSTD_REP_CHECK + (ip==anchor); - for (i=(ip == anchor); i<last_i; i++) { - const S32 repCur = (i==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : rep[i]; - if ( (repCur > 0) && (repCur < (S32)(ip-prefixStart)) - && (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(ip - repCur, minMatch))) { - mlen = (U32)ZSTD_count(ip+minMatch, ip+minMatch-repCur, iend) + minMatch; - if (mlen > sufficient_len || mlen >= ZSTD_OPT_NUM) { - best_mlen = mlen; best_off = i; cur = 0; last_pos = 1; - goto _storeSequence; - } - best_off = i - (ip == anchor); - do { - price = ZSTD_getPrice(optStatePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra); - if (mlen > last_pos || price < opt[mlen].price) - SET_PRICE(mlen, mlen, i, litlen, price); /* note : macro modifies last_pos */ - mlen--; - } while (mlen >= minMatch); - } } } - - match_num = ZSTD_BtGetAllMatches_selectMLS(ctx, ip, iend, maxSearches, mls, matches, minMatch); - - if (!last_pos && !match_num) { ip++; continue; } - - if (match_num && (matches[match_num-1].len > sufficient_len || matches[match_num-1].len >= ZSTD_OPT_NUM)) { - best_mlen = matches[match_num-1].len; - best_off = matches[match_num-1].off; - cur = 0; - last_pos = 1; - goto _storeSequence; - } - - /* set prices using matches at position = 0 */ - best_mlen = (last_pos) ? last_pos : minMatch; - for (u = 0; u < match_num; u++) { - mlen = (u>0) ? matches[u-1].len+1 : best_mlen; - best_mlen = matches[u].len; - while (mlen <= best_mlen) { - price = ZSTD_getPrice(optStatePtr, litlen, anchor, matches[u].off-1, mlen - MINMATCH, ultra); - if (mlen > last_pos || price < opt[mlen].price) - SET_PRICE(mlen, mlen, matches[u].off, litlen, price); /* note : macro modifies last_pos */ - mlen++; - } } - - if (last_pos < minMatch) { ip++; continue; } - - /* initialize opt[0] */ - { U32 i ; for (i=0; i<ZSTD_REP_NUM; i++) opt[0].rep[i] = rep[i]; } - opt[0].mlen = 1; - opt[0].litlen = litlen; - - /* check further positions */ - for (cur = 1; cur <= last_pos; cur++) { - inr = ip + cur; - - if (opt[cur-1].mlen == 1) { - litlen = opt[cur-1].litlen + 1; - if (cur > litlen) { - price = opt[cur - litlen].price + ZSTD_getLiteralPrice(optStatePtr, litlen, inr-litlen); - } else - price = ZSTD_getLiteralPrice(optStatePtr, litlen, anchor); - } else { - litlen = 1; - price = opt[cur - 1].price + ZSTD_getLiteralPrice(optStatePtr, litlen, inr-1); - } - - if (cur > last_pos || price <= opt[cur].price) - SET_PRICE(cur, 1, 0, litlen, price); - - if (cur == last_pos) break; - - if (inr > ilimit) /* last match must start at a minimum distance of 8 from oend */ - continue; - - mlen = opt[cur].mlen; - if (opt[cur].off > ZSTD_REP_MOVE_OPT) { - opt[cur].rep[2] = opt[cur-mlen].rep[1]; - opt[cur].rep[1] = opt[cur-mlen].rep[0]; - opt[cur].rep[0] = opt[cur].off - ZSTD_REP_MOVE_OPT; - } else { - opt[cur].rep[2] = (opt[cur].off > 1) ? opt[cur-mlen].rep[1] : opt[cur-mlen].rep[2]; - opt[cur].rep[1] = (opt[cur].off > 0) ? opt[cur-mlen].rep[0] : opt[cur-mlen].rep[1]; - /* If opt[cur].off == ZSTD_REP_MOVE_OPT, then mlen != 1. - * offset ZSTD_REP_MOVE_OPT is used for the special case - * litLength == 0, where offset 0 means something special. - * mlen == 1 means the previous byte was stored as a literal, - * so they are mutually exclusive. - */ - assert(!(opt[cur].off == ZSTD_REP_MOVE_OPT && mlen == 1)); - opt[cur].rep[0] = (opt[cur].off == ZSTD_REP_MOVE_OPT) ? (opt[cur-mlen].rep[0] - 1) : (opt[cur-mlen].rep[opt[cur].off]); - } - - best_mlen = minMatch; - { U32 i, last_i = ZSTD_REP_CHECK + (mlen != 1); - for (i=(opt[cur].mlen != 1); i<last_i; i++) { /* check rep */ - const S32 repCur = (i==ZSTD_REP_MOVE_OPT) ? (opt[cur].rep[0] - 1) : opt[cur].rep[i]; - if ( (repCur > 0) && (repCur < (S32)(inr-prefixStart)) - && (ZSTD_readMINMATCH(inr, minMatch) == ZSTD_readMINMATCH(inr - repCur, minMatch))) { - mlen = (U32)ZSTD_count(inr+minMatch, inr+minMatch - repCur, iend) + minMatch; - - if (mlen > sufficient_len || cur + mlen >= ZSTD_OPT_NUM) { - best_mlen = mlen; best_off = i; last_pos = cur + 1; - goto _storeSequence; - } - - best_off = i - (opt[cur].mlen != 1); - if (mlen > best_mlen) best_mlen = mlen; - - do { - if (opt[cur].mlen == 1) { - litlen = opt[cur].litlen; - if (cur > litlen) { - price = opt[cur - litlen].price + ZSTD_getPrice(optStatePtr, litlen, inr-litlen, best_off, mlen - MINMATCH, ultra); - } else - price = ZSTD_getPrice(optStatePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra); - } else { - litlen = 0; - price = opt[cur].price + ZSTD_getPrice(optStatePtr, 0, NULL, best_off, mlen - MINMATCH, ultra); - } - - if (cur + mlen > last_pos || price <= opt[cur + mlen].price) - SET_PRICE(cur + mlen, mlen, i, litlen, price); - mlen--; - } while (mlen >= minMatch); - } } } - - match_num = ZSTD_BtGetAllMatches_selectMLS(ctx, inr, iend, maxSearches, mls, matches, best_mlen); - - if (match_num > 0 && (matches[match_num-1].len > sufficient_len || cur + matches[match_num-1].len >= ZSTD_OPT_NUM)) { - best_mlen = matches[match_num-1].len; - best_off = matches[match_num-1].off; - last_pos = cur + 1; - goto _storeSequence; - } - - /* set prices using matches at position = cur */ - for (u = 0; u < match_num; u++) { - mlen = (u>0) ? matches[u-1].len+1 : best_mlen; - best_mlen = matches[u].len; - - while (mlen <= best_mlen) { - if (opt[cur].mlen == 1) { - litlen = opt[cur].litlen; - if (cur > litlen) - price = opt[cur - litlen].price + ZSTD_getPrice(optStatePtr, litlen, ip+cur-litlen, matches[u].off-1, mlen - MINMATCH, ultra); - else - price = ZSTD_getPrice(optStatePtr, litlen, anchor, matches[u].off-1, mlen - MINMATCH, ultra); - } else { - litlen = 0; - price = opt[cur].price + ZSTD_getPrice(optStatePtr, 0, NULL, matches[u].off-1, mlen - MINMATCH, ultra); - } - - if (cur + mlen > last_pos || (price < opt[cur + mlen].price)) - SET_PRICE(cur + mlen, mlen, matches[u].off, litlen, price); +typedef struct repcodes_s { + U32 rep[3]; +} repcodes_t; - mlen++; - } } } - - best_mlen = opt[last_pos].mlen; - best_off = opt[last_pos].off; - cur = last_pos - best_mlen; - - /* store sequence */ -_storeSequence: /* cur, last_pos, best_mlen, best_off have to be set */ - opt[0].mlen = 1; - - while (1) { - mlen = opt[cur].mlen; - offset = opt[cur].off; - opt[cur].mlen = best_mlen; - opt[cur].off = best_off; - best_mlen = mlen; - best_off = offset; - if (mlen > cur) break; - cur -= mlen; - } - - for (u = 0; u <= last_pos;) { - u += opt[u].mlen; +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; +} - for (cur=0; cur < last_pos; ) { - mlen = opt[cur].mlen; - if (mlen == 1) { ip++; cur++; continue; } - offset = opt[cur].off; - cur += mlen; - litLength = (U32)(ip - anchor); - - if (offset > ZSTD_REP_MOVE_OPT) { - rep[2] = rep[1]; - rep[1] = rep[0]; - rep[0] = offset - ZSTD_REP_MOVE_OPT; - offset--; - } else { - if (offset != 0) { - best_off = (offset==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : (rep[offset]); - if (offset != 1) rep[2] = rep[1]; - rep[1] = rep[0]; - rep[0] = best_off; - } - if (litLength==0) offset--; - } - ZSTD_updatePrice(optStatePtr, litLength, anchor, offset, mlen-MINMATCH); - ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, mlen-MINMATCH); - anchor = ip = ip + mlen; - } } /* for (cur=0; cur < last_pos; ) */ +typedef struct { + const BYTE* anchor; + U32 litlen; + U32 rawLitCost; +} cachedLiteralPrice_t; - /* Save reps for next block */ - { int i; for (i=0; i<ZSTD_REP_NUM; i++) seqStorePtr->repToConfirm[i] = rep[i]; } +static U32 ZSTD_rawLiteralsCost_cached( + cachedLiteralPrice_t* const cachedLitPrice, + const BYTE* const anchor, U32 const litlen, + const optState_t* const optStatePtr) +{ + U32 startCost; + U32 remainingLength; + const BYTE* startPosition; + + if (anchor == cachedLitPrice->anchor) { + startCost = cachedLitPrice->rawLitCost; + startPosition = anchor + cachedLitPrice->litlen; + assert(litlen >= cachedLitPrice->litlen); + remainingLength = litlen - cachedLitPrice->litlen; + } else { + startCost = 0; + startPosition = anchor; + remainingLength = litlen; + } - /* Return the last literals size */ - return iend - anchor; + { U32 const rawLitCost = startCost + ZSTD_rawLiteralsCost(startPosition, remainingLength, optStatePtr); + cachedLitPrice->anchor = anchor; + cachedLitPrice->litlen = litlen; + cachedLitPrice->rawLitCost = rawLitCost; + return rawLitCost; + } } - -size_t ZSTD_compressBlock_btopt(ZSTD_CCtx* ctx, const void* src, size_t srcSize) +static U32 ZSTD_fullLiteralsCost_cached( + cachedLiteralPrice_t* const cachedLitPrice, + const BYTE* const anchor, U32 const litlen, + const optState_t* const optStatePtr) { - return ZSTD_compressBlock_opt_generic(ctx, src, srcSize, 0); + return ZSTD_rawLiteralsCost_cached(cachedLitPrice, anchor, litlen, optStatePtr) + + ZSTD_litLengthPrice(litlen, optStatePtr); } -size_t ZSTD_compressBlock_btultra(ZSTD_CCtx* ctx, const void* src, size_t srcSize) +static int ZSTD_literalsContribution_cached( + cachedLiteralPrice_t* const cachedLitPrice, + const BYTE* const anchor, U32 const litlen, + const optState_t* const optStatePtr) { - return ZSTD_compressBlock_opt_generic(ctx, src, srcSize, 1); + int const contribution = ZSTD_rawLiteralsCost_cached(cachedLitPrice, anchor, litlen, optStatePtr) + + ZSTD_litLengthContribution(litlen, optStatePtr); + return contribution; } - FORCE_INLINE_TEMPLATE -size_t ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx* ctx, - const void* src, size_t srcSize, const int ultra) +size_t ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx, + const void* src, size_t srcSize, + const int optLevel, const int extDict) { - seqStore_t* seqStorePtr = &(ctx->seqStore); - optState_t* optStatePtr = &(ctx->optState); + seqStore_t* const seqStorePtr = &(ctx->seqStore); + optState_t* const optStatePtr = &(ctx->optState); const BYTE* const istart = (const BYTE*)src; const BYTE* ip = istart; const BYTE* anchor = istart; const BYTE* const iend = istart + srcSize; const BYTE* const ilimit = iend - 8; const BYTE* const base = ctx->base; - const U32 lowestIndex = ctx->lowLimit; - const U32 dictLimit = ctx->dictLimit; - const BYTE* const prefixStart = base + dictLimit; - const BYTE* const dictBase = ctx->dictBase; - const BYTE* const dictEnd = dictBase + dictLimit; + const BYTE* const prefixStart = base + ctx->dictLimit; - const U32 maxSearches = 1U << ctx->appliedParams.cParams.searchLog; - const U32 sufficient_len = ctx->appliedParams.cParams.targetLength; - const U32 mls = ctx->appliedParams.cParams.searchLength; - const U32 minMatch = (ctx->appliedParams.cParams.searchLength == 3) ? 3 : 4; + U32 const maxSearches = 1U << ctx->appliedParams.cParams.searchLog; + U32 const sufficient_len = MIN(ctx->appliedParams.cParams.targetLength, ZSTD_OPT_NUM -1); + U32 const mls = ctx->appliedParams.cParams.searchLength; + U32 const minMatch = (ctx->appliedParams.cParams.searchLength == 3) ? 3 : 4; - ZSTD_optimal_t* opt = optStatePtr->priceTable; - ZSTD_match_t* matches = optStatePtr->matchTable; - const BYTE* inr; + ZSTD_optimal_t* const opt = optStatePtr->priceTable; + ZSTD_match_t* const matches = optStatePtr->matchTable; + cachedLiteralPrice_t cachedLitPrice; + U32 rep[ZSTD_REP_NUM]; /* init */ - U32 offset, rep[ZSTD_REP_NUM]; - { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) rep[i]=seqStorePtr->rep[i]; } - + DEBUGLOG(5, "ZSTD_compressBlock_opt_generic"); ctx->nextToUpdate3 = ctx->nextToUpdate; ZSTD_rescaleFreqs(optStatePtr, (const BYTE*)src, srcSize); ip += (ip==prefixStart); + { int i; for (i=0; i<ZSTD_REP_NUM; i++) rep[i]=seqStorePtr->rep[i]; } + memset(&cachedLitPrice, 0, sizeof(cachedLitPrice)); /* Match Loop */ while (ip < ilimit) { - U32 cur, match_num, last_pos, litlen, price; - U32 u, mlen, best_mlen, best_off, litLength; - U32 current = (U32)(ip-base); - memset(opt, 0, sizeof(ZSTD_optimal_t)); - last_pos = 0; - opt[0].litlen = (U32)(ip - anchor); - - /* check repCode */ - { U32 i, last_i = ZSTD_REP_CHECK + (ip==anchor); - for (i = (ip==anchor); i<last_i; i++) { - const S32 repCur = (i==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : rep[i]; - const U32 repIndex = (U32)(current - repCur); - const BYTE* const repBase = repIndex < dictLimit ? dictBase : base; - const BYTE* const repMatch = repBase + repIndex; - if ( (repCur > 0 && repCur <= (S32)current) - && (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex>lowestIndex)) /* intentional overflow */ - && (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch)) ) { - /* repcode detected we should take it */ - const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend; - mlen = (U32)ZSTD_count_2segments(ip+minMatch, repMatch+minMatch, iend, repEnd, prefixStart) + minMatch; - - if (mlen > sufficient_len || mlen >= ZSTD_OPT_NUM) { - best_mlen = mlen; best_off = i; cur = 0; last_pos = 1; - goto _storeSequence; - } - - best_off = i - (ip==anchor); - litlen = opt[0].litlen; - do { - price = ZSTD_getPrice(optStatePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra); - if (mlen > last_pos || price < opt[mlen].price) - SET_PRICE(mlen, mlen, i, litlen, price); /* note : macro modifies last_pos */ - mlen--; - } while (mlen >= minMatch); - } } } - - match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, ip, iend, maxSearches, mls, matches, minMatch); /* first search (depth 0) */ - - if (!last_pos && !match_num) { ip++; continue; } - - { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) opt[0].rep[i] = rep[i]; } - opt[0].mlen = 1; - - if (match_num && (matches[match_num-1].len > sufficient_len || matches[match_num-1].len >= ZSTD_OPT_NUM)) { - best_mlen = matches[match_num-1].len; - best_off = matches[match_num-1].off; - cur = 0; - last_pos = 1; - goto _storeSequence; - } - - best_mlen = (last_pos) ? last_pos : minMatch; - - /* set prices using matches at position = 0 */ - for (u = 0; u < match_num; u++) { - mlen = (u>0) ? matches[u-1].len+1 : best_mlen; - best_mlen = matches[u].len; - litlen = opt[0].litlen; - while (mlen <= best_mlen) { - price = ZSTD_getPrice(optStatePtr, litlen, anchor, matches[u].off-1, mlen - MINMATCH, ultra); - if (mlen > last_pos || price < opt[mlen].price) - SET_PRICE(mlen, mlen, matches[u].off, litlen, price); - mlen++; - } } - - if (last_pos < minMatch) { - ip++; continue; + U32 cur, last_pos = 0; + U32 best_mlen, best_off; + + /* find first match */ + { U32 const litlen = (U32)(ip - anchor); + U32 const ll0 = !litlen; + U32 const nbMatches = ZSTD_BtGetAllMatches(ctx, ip, iend, extDict, maxSearches, mls, sufficient_len, rep, ll0, matches, 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 = 1; + opt[0].litlen = litlen; + + /* large match -> immediate encoding */ + { U32 const maxML = matches[nbMatches-1].len; + DEBUGLOG(7, "found %u matches of maxLength=%u and offset=%u at cPos=%u => start new serie", + nbMatches, maxML, matches[nbMatches-1].off, (U32)(ip-prefixStart)); + + if (maxML > sufficient_len) { + best_mlen = maxML; + best_off = matches[nbMatches-1].off; + DEBUGLOG(7, "large match (%u>%u), immediate encoding", + best_mlen, sufficient_len); + cur = 0; + last_pos = 1; + goto _shortestPath; + } } + + /* set prices for first matches starting position == 0 */ + { U32 const literalsPrice = ZSTD_fullLiteralsCost_cached(&cachedLitPrice, anchor, litlen, optStatePtr); + U32 pos; + U32 matchNb; + for (pos = 0; pos < minMatch; pos++) { + opt[pos].mlen = 1; + opt[pos].price = ZSTD_MAX_PRICE; + } + 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 = literalsPrice + ZSTD_getMatchPrice(offset, pos, optStatePtr, optLevel); + DEBUGLOG(7, "rPos:%u => set initial price : %u", + pos, matchPrice); + opt[pos].mlen = pos; + opt[pos].off = offset; + opt[pos].litlen = litlen; + opt[pos].price = matchPrice; + memcpy(opt[pos].rep, &repHistory, sizeof(repHistory)); + } } + last_pos = pos-1; + } } /* check further positions */ for (cur = 1; cur <= last_pos; cur++) { - inr = ip + cur; + const BYTE* const inr = ip + cur; + assert(cur < ZSTD_OPT_NUM); - if (opt[cur-1].mlen == 1) { - litlen = opt[cur-1].litlen + 1; + /* Fix current position with one literal if cheaper */ + { U32 const litlen = (opt[cur-1].mlen == 1) ? opt[cur-1].litlen + 1 : 1; + int price; /* note : contribution can be negative */ if (cur > litlen) { - price = opt[cur - litlen].price + ZSTD_getLiteralPrice(optStatePtr, litlen, inr-litlen); - } else - price = ZSTD_getLiteralPrice(optStatePtr, litlen, anchor); - } else { - litlen = 1; - price = opt[cur - 1].price + ZSTD_getLiteralPrice(optStatePtr, litlen, inr-1); - } - - if (cur > last_pos || price <= opt[cur].price) - SET_PRICE(cur, 1, 0, litlen, price); + price = opt[cur - litlen].price + ZSTD_literalsContribution(inr-litlen, litlen, optStatePtr); + } else { + price = ZSTD_literalsContribution_cached(&cachedLitPrice, anchor, litlen, optStatePtr); + } + assert(price < 1000000000); /* overflow check */ + if (price <= opt[cur].price) { + DEBUGLOG(7, "rPos:%u : better price (%u<%u) using literal", + cur, price, opt[cur].price); + opt[cur].mlen = 1; + opt[cur].off = 0; + opt[cur].litlen = litlen; + opt[cur].price = price; + memcpy(opt[cur].rep, opt[cur-1].rep, sizeof(opt[cur].rep)); + } } + + /* last match must start at a minimum distance of 8 from oend */ + if (inr > ilimit) continue; if (cur == last_pos) break; - if (inr > ilimit) /* last match must start at a minimum distance of 8 from oend */ - continue; - - mlen = opt[cur].mlen; - if (opt[cur].off > ZSTD_REP_MOVE_OPT) { - opt[cur].rep[2] = opt[cur-mlen].rep[1]; - opt[cur].rep[1] = opt[cur-mlen].rep[0]; - opt[cur].rep[0] = opt[cur].off - ZSTD_REP_MOVE_OPT; - } else { - opt[cur].rep[2] = (opt[cur].off > 1) ? opt[cur-mlen].rep[1] : opt[cur-mlen].rep[2]; - opt[cur].rep[1] = (opt[cur].off > 0) ? opt[cur-mlen].rep[0] : opt[cur-mlen].rep[1]; - assert(!(opt[cur].off == ZSTD_REP_MOVE_OPT && mlen == 1)); - opt[cur].rep[0] = (opt[cur].off == ZSTD_REP_MOVE_OPT) ? (opt[cur-mlen].rep[0] - 1) : (opt[cur-mlen].rep[opt[cur].off]); - } + if ( (optLevel==0) /*static*/ + && (opt[cur+1].price <= opt[cur].price) ) + continue; /* skip unpromising positions; about ~+6% speed, -0.01 ratio */ + + { U32 const ll0 = (opt[cur].mlen != 1); + U32 const litlen = (opt[cur].mlen == 1) ? opt[cur].litlen : 0; + U32 const previousPrice = (cur > litlen) ? opt[cur-litlen].price : 0; + U32 const basePrice = previousPrice + ZSTD_fullLiteralsCost(inr-litlen, litlen, optStatePtr); + U32 const nbMatches = ZSTD_BtGetAllMatches(ctx, inr, iend, extDict, maxSearches, mls, sufficient_len, opt[cur].rep, ll0, matches, minMatch); + U32 matchNb; + if (!nbMatches) continue; + + { U32 const maxML = matches[nbMatches-1].len; + DEBUGLOG(7, "rPos:%u, found %u matches, of maxLength=%u", + cur, nbMatches, maxML); + + if ( (maxML > sufficient_len) + | (cur + maxML >= ZSTD_OPT_NUM) ) { + best_mlen = maxML; + best_off = matches[nbMatches-1].off; + last_pos = cur + 1; + goto _shortestPath; + } + } - best_mlen = minMatch; - { U32 i, last_i = ZSTD_REP_CHECK + (mlen != 1); - for (i = (mlen != 1); i<last_i; i++) { - const S32 repCur = (i==ZSTD_REP_MOVE_OPT) ? (opt[cur].rep[0] - 1) : opt[cur].rep[i]; - const U32 repIndex = (U32)(current+cur - repCur); - const BYTE* const repBase = repIndex < dictLimit ? dictBase : base; - const BYTE* const repMatch = repBase + repIndex; - if ( (repCur > 0 && repCur <= (S32)(current+cur)) - && (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex>lowestIndex)) /* intentional overflow */ - && (ZSTD_readMINMATCH(inr, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch)) ) { - /* repcode detected */ - const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend; - mlen = (U32)ZSTD_count_2segments(inr+minMatch, repMatch+minMatch, iend, repEnd, prefixStart) + minMatch; - - if (mlen > sufficient_len || cur + mlen >= ZSTD_OPT_NUM) { - best_mlen = mlen; best_off = i; last_pos = cur + 1; - goto _storeSequence; + /* 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; + + DEBUGLOG(7, "testing match %u => offCode=%u, mlen=%u, llen=%u", + matchNb, matches[matchNb].off, lastML, litlen); + + for (mlen = lastML; mlen >= startML; mlen--) { + U32 const pos = cur + mlen; + int const price = basePrice + ZSTD_getMatchPrice(offset, mlen, optStatePtr, optLevel); + + if ((pos > last_pos) || (price < opt[pos].price)) { + DEBUGLOG(7, "rPos:%u => new better price (%u<%u)", + pos, price, opt[pos].price); + while (last_pos < pos) { opt[last_pos+1].price = ZSTD_MAX_PRICE; last_pos++; } + opt[pos].mlen = mlen; + opt[pos].off = offset; + opt[pos].litlen = litlen; + opt[pos].price = price; + memcpy(opt[pos].rep, &repHistory, sizeof(repHistory)); + } else { + if (optLevel==0) break; /* gets ~+10% speed for about -0.01 ratio loss */ } - - best_off = i - (opt[cur].mlen != 1); - if (mlen > best_mlen) best_mlen = mlen; - - do { - if (opt[cur].mlen == 1) { - litlen = opt[cur].litlen; - if (cur > litlen) { - price = opt[cur - litlen].price + ZSTD_getPrice(optStatePtr, litlen, inr-litlen, best_off, mlen - MINMATCH, ultra); - } else - price = ZSTD_getPrice(optStatePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra); - } else { - litlen = 0; - price = opt[cur].price + ZSTD_getPrice(optStatePtr, 0, NULL, best_off, mlen - MINMATCH, ultra); - } - - if (cur + mlen > last_pos || price <= opt[cur + mlen].price) - SET_PRICE(cur + mlen, mlen, i, litlen, price); - mlen--; - } while (mlen >= minMatch); } } } - - match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, inr, iend, maxSearches, mls, matches, minMatch); - - if (match_num > 0 && (matches[match_num-1].len > sufficient_len || cur + matches[match_num-1].len >= ZSTD_OPT_NUM)) { - best_mlen = matches[match_num-1].len; - best_off = matches[match_num-1].off; - last_pos = cur + 1; - goto _storeSequence; - } - - /* set prices using matches at position = cur */ - for (u = 0; u < match_num; u++) { - mlen = (u>0) ? matches[u-1].len+1 : best_mlen; - best_mlen = matches[u].len; - - while (mlen <= best_mlen) { - if (opt[cur].mlen == 1) { - litlen = opt[cur].litlen; - if (cur > litlen) - price = opt[cur - litlen].price + ZSTD_getPrice(optStatePtr, litlen, ip+cur-litlen, matches[u].off-1, mlen - MINMATCH, ultra); - else - price = ZSTD_getPrice(optStatePtr, litlen, anchor, matches[u].off-1, mlen - MINMATCH, ultra); - } else { - litlen = 0; - price = opt[cur].price + ZSTD_getPrice(optStatePtr, 0, NULL, matches[u].off-1, mlen - MINMATCH, ultra); - } - - if (cur + mlen > last_pos || (price < opt[cur + mlen].price)) - SET_PRICE(cur + mlen, mlen, matches[u].off, litlen, price); - - mlen++; - } } } /* for (cur = 1; cur <= last_pos; cur++) */ + } /* for (cur = 1; cur <= last_pos; cur++) */ best_mlen = opt[last_pos].mlen; best_off = opt[last_pos].off; cur = last_pos - best_mlen; - /* store sequence */ -_storeSequence: /* cur, last_pos, best_mlen, best_off have to be set */ - opt[0].mlen = 1; - - while (1) { - mlen = opt[cur].mlen; - offset = opt[cur].off; - opt[cur].mlen = best_mlen; - opt[cur].off = best_off; - best_mlen = mlen; - best_off = offset; - if (mlen > cur) break; - cur -= mlen; - } - - for (u = 0; u <= last_pos; ) { - u += opt[u].mlen; - } +_shortestPath: /* cur, last_pos, best_mlen, best_off have to be set */ + assert(opt[0].mlen == 1); + + /* reverse traversal */ + DEBUGLOG(7, "start reverse traversal (last_pos:%u, cur:%u)", + last_pos, cur); + { U32 selectedMatchLength = best_mlen; + U32 selectedOffset = best_off; + U32 pos = cur; + while (1) { + U32 const mlen = opt[pos].mlen; + U32 const off = opt[pos].off; + opt[pos].mlen = selectedMatchLength; + opt[pos].off = selectedOffset; + selectedMatchLength = mlen; + selectedOffset = off; + if (mlen > pos) break; + pos -= mlen; + } } - for (cur=0; cur < last_pos; ) { - mlen = opt[cur].mlen; - if (mlen == 1) { ip++; cur++; continue; } - offset = opt[cur].off; - cur += mlen; - litLength = (U32)(ip - anchor); - - if (offset > ZSTD_REP_MOVE_OPT) { - rep[2] = rep[1]; - rep[1] = rep[0]; - rep[0] = offset - ZSTD_REP_MOVE_OPT; - offset--; - } else { - if (offset != 0) { - best_off = (offset==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : (rep[offset]); - if (offset != 1) rep[2] = rep[1]; + /* save sequences */ + { U32 pos; + for (pos=0; pos < last_pos; ) { + U32 const llen = (U32)(ip - anchor); + U32 const mlen = opt[pos].mlen; + U32 const offset = opt[pos].off; + if (mlen == 1) { ip++; pos++; continue; } /* literal position => move on */ + pos += mlen; ip += mlen; + + /* repcodes update : like ZSTD_updateRep(), but update in place */ + if (offset >= ZSTD_REP_NUM) { /* full offset */ + rep[2] = rep[1]; rep[1] = rep[0]; - rep[0] = best_off; + rep[0] = offset - ZSTD_REP_MOVE; + } else { /* repcode */ + U32 const repCode = offset + (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; + } } - if (litLength==0) offset--; - } - - ZSTD_updatePrice(optStatePtr, litLength, anchor, offset, mlen-MINMATCH); - ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, mlen-MINMATCH); - anchor = ip = ip + mlen; - } } /* for (cur=0; cur < last_pos; ) */ + ZSTD_updateStats(optStatePtr, llen, anchor, offset, mlen); + ZSTD_storeSeq(seqStorePtr, llen, anchor, offset, mlen-MINMATCH); + anchor = ip; + } } + ZSTD_setLog2Prices(optStatePtr); + } /* while (ip < ilimit) */ /* Save reps for next block */ { int i; for (i=0; i<ZSTD_REP_NUM; i++) seqStorePtr->repToConfirm[i] = rep[i]; } @@ -946,12 +763,23 @@ _storeSequence: /* cur, last_pos, best_mlen, best_off have to be set */ } +size_t ZSTD_compressBlock_btopt(ZSTD_CCtx* ctx, const void* src, size_t srcSize) +{ + DEBUGLOG(5, "ZSTD_compressBlock_btopt"); + return ZSTD_compressBlock_opt_generic(ctx, src, srcSize, 0 /*optLevel*/, 0 /*extDict*/); +} + +size_t ZSTD_compressBlock_btultra(ZSTD_CCtx* ctx, const void* src, size_t srcSize) +{ + return ZSTD_compressBlock_opt_generic(ctx, src, srcSize, 2 /*optLevel*/, 0 /*extDict*/); +} + size_t ZSTD_compressBlock_btopt_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize) { - return ZSTD_compressBlock_opt_extDict_generic(ctx, src, srcSize, 0); + return ZSTD_compressBlock_opt_generic(ctx, src, srcSize, 0 /*optLevel*/, 1 /*extDict*/); } size_t ZSTD_compressBlock_btultra_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize) { - return ZSTD_compressBlock_opt_extDict_generic(ctx, src, srcSize, 1); + return ZSTD_compressBlock_opt_generic(ctx, src, srcSize, 2 /*optLevel*/, 1 /*extDict*/); } |