zstd_opt.c
1132 lines
| 51.5 KiB
| text/x-c
|
CLexer
|
r37513 | /* | ||
* Copyright (c) 2016-present, Przemyslaw Skibinski, Yann Collet, Facebook, Inc. | ||||
* All rights reserved. | ||||
* | ||||
* This source code is licensed under both the BSD-style license (found in the | ||||
* LICENSE file in the root directory of this source tree) and the GPLv2 (found | ||||
* in the COPYING file in the root directory of this source tree). | ||||
* You may select, at your option, one of the above-listed licenses. | ||||
*/ | ||||
#include "zstd_compress_internal.h" | ||||
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r40157 | #include "hist.h" | ||
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r37513 | #include "zstd_opt.h" | ||
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r40157 | #define ZSTD_LITFREQ_ADD 2 /* scaling factor for litFreq, so that frequencies adapt faster to new stats */ | ||
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r37513 | #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 | ||||
***************************************/ | ||||
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r40157 | |||
#if 0 /* approximation at bit level */ | ||||
# define BITCOST_ACCURACY 0 | ||||
# define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY) | ||||
# define WEIGHT(stat) ((void)opt, ZSTD_bitWeight(stat)) | ||||
#elif 0 /* fractional bit accuracy */ | ||||
# define BITCOST_ACCURACY 8 | ||||
# define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY) | ||||
# define WEIGHT(stat,opt) ((void)opt, ZSTD_fracWeight(stat)) | ||||
#else /* opt==approx, ultra==accurate */ | ||||
# define BITCOST_ACCURACY 8 | ||||
# define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY) | ||||
# define WEIGHT(stat,opt) (opt ? ZSTD_fracWeight(stat) : ZSTD_bitWeight(stat)) | ||||
#endif | ||||
MEM_STATIC U32 ZSTD_bitWeight(U32 stat) | ||||
{ | ||||
return (ZSTD_highbit32(stat+1) * BITCOST_MULTIPLIER); | ||||
} | ||||
MEM_STATIC U32 ZSTD_fracWeight(U32 rawStat) | ||||
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r37513 | { | ||
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r40157 | U32 const stat = rawStat + 1; | ||
U32 const hb = ZSTD_highbit32(stat); | ||||
U32 const BWeight = hb * BITCOST_MULTIPLIER; | ||||
U32 const FWeight = (stat << BITCOST_ACCURACY) >> hb; | ||||
U32 const weight = BWeight + FWeight; | ||||
assert(hb + BITCOST_ACCURACY < 31); | ||||
return weight; | ||||
} | ||||
/* debugging function, @return price in bytes */ | ||||
MEM_STATIC double ZSTD_fCost(U32 price) | ||||
{ | ||||
return (double)price / (BITCOST_MULTIPLIER*8); | ||||
} | ||||
static void ZSTD_setBasePrices(optState_t* optPtr, int optLevel) | ||||
{ | ||||
optPtr->litSumBasePrice = WEIGHT(optPtr->litSum, optLevel); | ||||
optPtr->litLengthSumBasePrice = WEIGHT(optPtr->litLengthSum, optLevel); | ||||
optPtr->matchLengthSumBasePrice = WEIGHT(optPtr->matchLengthSum, optLevel); | ||||
optPtr->offCodeSumBasePrice = WEIGHT(optPtr->offCodeSum, optLevel); | ||||
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r37513 | } | ||
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r40157 | static U32 ZSTD_downscaleStat(U32* table, U32 lastEltIndex, int malus) | ||
{ | ||||
U32 s, sum=0; | ||||
assert(ZSTD_FREQ_DIV+malus > 0 && ZSTD_FREQ_DIV+malus < 31); | ||||
for (s=0; s<=lastEltIndex; s++) { | ||||
table[s] = 1 + (table[s] >> (ZSTD_FREQ_DIV+malus)); | ||||
sum += table[s]; | ||||
} | ||||
return sum; | ||||
} | ||||
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r37513 | static void ZSTD_rescaleFreqs(optState_t* const optPtr, | ||
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r40157 | const BYTE* const src, size_t const srcSize, | ||
int optLevel) | ||||
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r37513 | { | ||
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r40157 | optPtr->priceType = zop_dynamic; | ||
if (optPtr->litLengthSum == 0) { /* first block : init */ | ||||
if (srcSize <= 1024) /* heuristic */ | ||||
optPtr->priceType = zop_predef; | ||||
assert(optPtr->symbolCosts != NULL); | ||||
if (optPtr->symbolCosts->huf.repeatMode == HUF_repeat_valid) { /* huffman table presumed generated by dictionary */ | ||||
optPtr->priceType = zop_dynamic; | ||||
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r37513 | |||
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r40157 | assert(optPtr->litFreq != NULL); | ||
optPtr->litSum = 0; | ||||
{ unsigned lit; | ||||
for (lit=0; lit<=MaxLit; lit++) { | ||||
U32 const scaleLog = 11; /* scale to 2K */ | ||||
U32 const bitCost = HUF_getNbBits(optPtr->symbolCosts->huf.CTable, lit); | ||||
assert(bitCost <= scaleLog); | ||||
optPtr->litFreq[lit] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/; | ||||
optPtr->litSum += optPtr->litFreq[lit]; | ||||
} } | ||||
{ unsigned ll; | ||||
FSE_CState_t llstate; | ||||
FSE_initCState(&llstate, optPtr->symbolCosts->fse.litlengthCTable); | ||||
optPtr->litLengthSum = 0; | ||||
for (ll=0; ll<=MaxLL; ll++) { | ||||
U32 const scaleLog = 10; /* scale to 1K */ | ||||
U32 const bitCost = FSE_getMaxNbBits(llstate.symbolTT, ll); | ||||
assert(bitCost < scaleLog); | ||||
optPtr->litLengthFreq[ll] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/; | ||||
optPtr->litLengthSum += optPtr->litLengthFreq[ll]; | ||||
} } | ||||
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r37513 | |||
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r40157 | { unsigned ml; | ||
FSE_CState_t mlstate; | ||||
FSE_initCState(&mlstate, optPtr->symbolCosts->fse.matchlengthCTable); | ||||
optPtr->matchLengthSum = 0; | ||||
for (ml=0; ml<=MaxML; ml++) { | ||||
U32 const scaleLog = 10; | ||||
U32 const bitCost = FSE_getMaxNbBits(mlstate.symbolTT, ml); | ||||
assert(bitCost < scaleLog); | ||||
optPtr->matchLengthFreq[ml] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/; | ||||
optPtr->matchLengthSum += optPtr->matchLengthFreq[ml]; | ||||
} } | ||||
{ unsigned of; | ||||
FSE_CState_t ofstate; | ||||
FSE_initCState(&ofstate, optPtr->symbolCosts->fse.offcodeCTable); | ||||
optPtr->offCodeSum = 0; | ||||
for (of=0; of<=MaxOff; of++) { | ||||
U32 const scaleLog = 10; | ||||
U32 const bitCost = FSE_getMaxNbBits(ofstate.symbolTT, of); | ||||
assert(bitCost < scaleLog); | ||||
optPtr->offCodeFreq[of] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/; | ||||
optPtr->offCodeSum += optPtr->offCodeFreq[of]; | ||||
} } | ||||
} else { /* not a dictionary */ | ||||
assert(optPtr->litFreq != NULL); | ||||
{ 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); | ||||
{ unsigned ll; | ||||
for (ll=0; ll<=MaxLL; ll++) | ||||
optPtr->litLengthFreq[ll] = 1; | ||||
} | ||||
optPtr->litLengthSum = MaxLL+1; | ||||
{ unsigned ml; | ||||
for (ml=0; ml<=MaxML; ml++) | ||||
optPtr->matchLengthFreq[ml] = 1; | ||||
} | ||||
optPtr->matchLengthSum = MaxML+1; | ||||
{ unsigned of; | ||||
for (of=0; of<=MaxOff; of++) | ||||
optPtr->offCodeFreq[of] = 1; | ||||
} | ||||
optPtr->offCodeSum = MaxOff+1; | ||||
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r37513 | } | ||
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r40157 | } else { /* new block : re-use previous statistics, scaled down */ | ||
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r37513 | |||
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r40157 | 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); | ||||
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r37513 | } | ||
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r40157 | ZSTD_setBasePrices(optPtr, optLevel); | ||
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r37513 | } | ||
/* ZSTD_rawLiteralsCost() : | ||||
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r40157 | * price of literals (only) in specified segment (which length can be 0). | ||
* does not include price of literalLength symbol */ | ||||
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r37513 | static U32 ZSTD_rawLiteralsCost(const BYTE* const literals, U32 const litLength, | ||
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r40157 | const optState_t* const optPtr, | ||
int optLevel) | ||||
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r37513 | { | ||
if (litLength == 0) return 0; | ||||
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r40157 | if (optPtr->priceType == zop_predef) | ||
return (litLength*6) * BITCOST_MULTIPLIER; /* 6 bit per literal - no statistic used */ | ||||
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r37513 | |||
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r40157 | /* dynamic statistics */ | ||
{ U32 price = litLength * optPtr->litSumBasePrice; | ||||
U32 u; | ||||
for (u=0; u < litLength; u++) { | ||||
assert(WEIGHT(optPtr->litFreq[literals[u]], optLevel) <= optPtr->litSumBasePrice); /* literal cost should never be negative */ | ||||
price -= WEIGHT(optPtr->litFreq[literals[u]], optLevel); | ||||
} | ||||
return price; | ||||
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r37513 | } | ||
} | ||||
/* ZSTD_litLengthPrice() : | ||||
* cost of literalLength symbol */ | ||||
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r40157 | static U32 ZSTD_litLengthPrice(U32 const litLength, const optState_t* const optPtr, int optLevel) | ||
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r37513 | { | ||
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r40157 | if (optPtr->priceType == zop_predef) return WEIGHT(litLength, optLevel); | ||
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r37513 | |||
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r40157 | /* dynamic statistics */ | ||
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r37513 | { U32 const llCode = ZSTD_LLcode(litLength); | ||
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r40157 | return (LL_bits[llCode] * BITCOST_MULTIPLIER) + (optPtr->litLengthSumBasePrice - WEIGHT(optPtr->litLengthFreq[llCode], optLevel)); | ||
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r37513 | } | ||
} | ||||
/* 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 */ | ||||
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r40157 | static int ZSTD_litLengthContribution(U32 const litLength, const optState_t* const optPtr, int optLevel) | ||
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r37513 | { | ||
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r40157 | if (optPtr->priceType >= zop_predef) return WEIGHT(litLength, optLevel); | ||
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r37513 | |||
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r40157 | /* dynamic statistics */ | ||
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r37513 | { U32 const llCode = ZSTD_LLcode(litLength); | ||
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r40157 | int const contribution = (LL_bits[llCode] * BITCOST_MULTIPLIER) | ||
+ WEIGHT(optPtr->litLengthFreq[0], optLevel) /* note: log2litLengthSum cancel out */ | ||||
- WEIGHT(optPtr->litLengthFreq[llCode], optLevel); | ||||
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r37513 | #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, | ||||
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r40157 | const optState_t* const optPtr, | ||
int optLevel) | ||||
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r37513 | { | ||
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r40157 | int const contribution = ZSTD_rawLiteralsCost(literals, litLength, optPtr, optLevel) | ||
+ ZSTD_litLengthContribution(litLength, optPtr, optLevel); | ||||
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r37513 | 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. | ||||
* optLevel: when <2, favors small offset for decompression speed (improved cache efficiency) */ | ||||
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r40157 | FORCE_INLINE_TEMPLATE U32 | ||
ZSTD_getMatchPrice(U32 const offset, | ||||
U32 const matchLength, | ||||
const optState_t* const optPtr, | ||||
int const optLevel) | ||||
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r37513 | { | ||
U32 price; | ||||
U32 const offCode = ZSTD_highbit32(offset+1); | ||||
U32 const mlBase = matchLength - MINMATCH; | ||||
assert(matchLength >= MINMATCH); | ||||
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r40157 | if (optPtr->priceType == zop_predef) /* fixed scheme, do not use statistics */ | ||
return WEIGHT(mlBase, optLevel) + ((16 + offCode) * BITCOST_MULTIPLIER); | ||||
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r37513 | |||
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r40157 | /* dynamic statistics */ | ||
price = (offCode * BITCOST_MULTIPLIER) + (optPtr->offCodeSumBasePrice - WEIGHT(optPtr->offCodeFreq[offCode], optLevel)); | ||||
if ((optLevel<2) /*static*/ && offCode >= 20) | ||||
price += (offCode-19)*2 * BITCOST_MULTIPLIER; /* handicap for long distance offsets, favor decompression speed */ | ||||
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r37513 | |||
/* match Length */ | ||||
{ U32 const mlCode = ZSTD_MLcode(mlBase); | ||||
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r40157 | price += (ML_bits[mlCode] * BITCOST_MULTIPLIER) + (optPtr->matchLengthSumBasePrice - WEIGHT(optPtr->matchLengthFreq[mlCode], optLevel)); | ||
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r37513 | } | ||
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r40157 | price += BITCOST_MULTIPLIER / 5; /* heuristic : make matches a bit more costly to favor less sequences -> faster decompression speed */ | ||
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r37513 | DEBUGLOG(8, "ZSTD_getMatchPrice(ml:%u) = %u", matchLength, price); | ||
return price; | ||||
} | ||||
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r40157 | /* ZSTD_updateStats() : | ||
* assumption : literals + litLengtn <= iend */ | ||||
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r37513 | static void ZSTD_updateStats(optState_t* const optPtr, | ||
U32 litLength, const BYTE* literals, | ||||
U32 offsetCode, U32 matchLength) | ||||
{ | ||||
/* literals */ | ||||
{ U32 u; | ||||
for (u=0; u < litLength; u++) | ||||
optPtr->litFreq[literals[u]] += ZSTD_LITFREQ_ADD; | ||||
optPtr->litSum += litLength*ZSTD_LITFREQ_ADD; | ||||
} | ||||
/* literal Length */ | ||||
{ U32 const llCode = ZSTD_LLcode(litLength); | ||||
optPtr->litLengthFreq[llCode]++; | ||||
optPtr->litLengthSum++; | ||||
} | ||||
/* 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 */ | ||||
{ U32 const mlBase = matchLength - MINMATCH; | ||||
U32 const mlCode = ZSTD_MLcode(mlBase); | ||||
optPtr->matchLengthFreq[mlCode]++; | ||||
optPtr->matchLengthSum++; | ||||
} | ||||
} | ||||
/* 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) | ||||
{ | ||||
default : | ||||
case 4 : return MEM_read32(memPtr); | ||||
case 3 : if (MEM_isLittleEndian()) | ||||
return MEM_read32(memPtr)<<8; | ||||
else | ||||
return MEM_read32(memPtr)>>8; | ||||
} | ||||
} | ||||
/* 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) | ||||
{ | ||||
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); | ||||
size_t const hash3 = ZSTD_hash3Ptr(ip, hashLog3); | ||||
assert(hashLog3 > 0); | ||||
while(idx < target) { | ||||
hashTable3[ZSTD_hash3Ptr(base+idx, hashLog3)] = idx; | ||||
idx++; | ||||
} | ||||
return hashTable3[hash3]; | ||||
} | ||||
/*-************************************* | ||||
* Binary Tree search | ||||
***************************************/ | ||||
/** ZSTD_insertBt1() : add one or multiple positions to tree. | ||||
* ip : assumed <= iend-8 . | ||||
* @return : nb of positions added */ | ||||
static U32 ZSTD_insertBt1( | ||||
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r40157 | ZSTD_matchState_t* ms, | ||
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r37513 | const BYTE* const ip, const BYTE* const iend, | ||
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r40157 | U32 const mls, const int extDict) | ||
|
r37513 | { | ||
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r40157 | const ZSTD_compressionParameters* const cParams = &ms->cParams; | ||
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r37513 | U32* const hashTable = ms->hashTable; | ||
U32 const hashLog = cParams->hashLog; | ||||
size_t const h = ZSTD_hashPtr(ip, hashLog, mls); | ||||
U32* const bt = ms->chainTable; | ||||
U32 const btLog = cParams->chainLog - 1; | ||||
U32 const btMask = (1 << btLog) - 1; | ||||
U32 matchIndex = hashTable[h]; | ||||
size_t commonLengthSmaller=0, commonLengthLarger=0; | ||||
const BYTE* const base = ms->window.base; | ||||
const BYTE* const dictBase = ms->window.dictBase; | ||||
const U32 dictLimit = ms->window.dictLimit; | ||||
const BYTE* const dictEnd = dictBase + dictLimit; | ||||
const BYTE* const prefixStart = base + dictLimit; | ||||
const BYTE* match; | ||||
const U32 current = (U32)(ip-base); | ||||
const U32 btLow = btMask >= current ? 0 : current - btMask; | ||||
U32* smallerPtr = bt + 2*(current&btMask); | ||||
U32* largerPtr = smallerPtr + 1; | ||||
U32 dummy32; /* to be nullified at the end */ | ||||
U32 const windowLow = ms->window.lowLimit; | ||||
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r40157 | U32 const matchLow = windowLow ? windowLow : 1; | ||
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r37513 | U32 matchEndIdx = current+8+1; | ||
size_t bestLength = 8; | ||||
U32 nbCompares = 1U << cParams->searchLog; | ||||
#ifdef ZSTD_C_PREDICT | ||||
U32 predictedSmall = *(bt + 2*((current-1)&btMask) + 0); | ||||
U32 predictedLarge = *(bt + 2*((current-1)&btMask) + 1); | ||||
predictedSmall += (predictedSmall>0); | ||||
predictedLarge += (predictedLarge>0); | ||||
#endif /* ZSTD_C_PREDICT */ | ||||
DEBUGLOG(8, "ZSTD_insertBt1 (%u)", current); | ||||
assert(ip <= iend-8); /* required for h calculation */ | ||||
hashTable[h] = current; /* Update Hash Table */ | ||||
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r40157 | while (nbCompares-- && (matchIndex >= matchLow)) { | ||
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r37513 | U32* const nextPtr = bt + 2*(matchIndex & btMask); | ||
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */ | ||||
assert(matchIndex < current); | ||||
#ifdef ZSTD_C_PREDICT /* note : can create issues when hlog small <= 11 */ | ||||
const U32* predictPtr = bt + 2*((matchIndex-1) & btMask); /* written this way, as bt is a roll buffer */ | ||||
if (matchIndex == predictedSmall) { | ||||
/* no need to check length, result known */ | ||||
*smallerPtr = matchIndex; | ||||
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) */ | ||||
predictedSmall = predictPtr[1] + (predictPtr[1]>0); | ||||
continue; | ||||
} | ||||
if (matchIndex == predictedLarge) { | ||||
*largerPtr = matchIndex; | ||||
if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */ | ||||
largerPtr = nextPtr; | ||||
matchIndex = nextPtr[0]; | ||||
predictedLarge = predictPtr[0] + (predictPtr[0]>0); | ||||
continue; | ||||
} | ||||
#endif | ||||
|
r40157 | if (!extDict || (matchIndex+matchLength >= dictLimit)) { | ||
assert(matchIndex+matchLength >= dictLimit); /* might be wrong if actually extDict */ | ||||
|
r37513 | match = base + matchIndex; | ||
matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend); | ||||
} else { | ||||
match = dictBase + matchIndex; | ||||
matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart); | ||||
if (matchIndex+matchLength >= dictLimit) | ||||
match = base + matchIndex; /* to prepare for next usage of match[matchLength] */ | ||||
} | ||||
if (matchLength > bestLength) { | ||||
bestLength = matchLength; | ||||
if (matchLength > matchEndIdx - matchIndex) | ||||
matchEndIdx = matchIndex + (U32)matchLength; | ||||
} | ||||
if (ip+matchLength == iend) { /* equal : no way to know if inf or sup */ | ||||
break; /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt tree */ | ||||
} | ||||
if (match[matchLength] < ip[matchLength]) { /* necessarily within buffer */ | ||||
/* match is 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 searching */ | ||||
smallerPtr = nextPtr+1; /* new "candidate" => larger than match, which was smaller than target */ | ||||
matchIndex = nextPtr[1]; /* new matchIndex, larger than previous and closer to current */ | ||||
} else { | ||||
/* match is larger than current */ | ||||
*largerPtr = matchIndex; | ||||
commonLengthLarger = matchLength; | ||||
if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop searching */ | ||||
largerPtr = nextPtr; | ||||
matchIndex = nextPtr[0]; | ||||
} } | ||||
*smallerPtr = *largerPtr = 0; | ||||
if (bestLength > 384) return MIN(192, (U32)(bestLength - 384)); /* speed optimization */ | ||||
assert(matchEndIdx > current + 8); | ||||
return matchEndIdx - (current + 8); | ||||
} | ||||
FORCE_INLINE_TEMPLATE | ||||
void ZSTD_updateTree_internal( | ||||
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r40157 | ZSTD_matchState_t* ms, | ||
|
r37513 | const BYTE* const ip, const BYTE* const iend, | ||
|
r40157 | const U32 mls, const ZSTD_dictMode_e dictMode) | ||
|
r37513 | { | ||
const BYTE* const base = ms->window.base; | ||||
U32 const target = (U32)(ip - base); | ||||
U32 idx = ms->nextToUpdate; | ||||
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r40157 | DEBUGLOG(5, "ZSTD_updateTree_internal, from %u to %u (dictMode:%u)", | ||
idx, target, dictMode); | ||||
|
r37513 | |||
while(idx < target) | ||||
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r40157 | idx += ZSTD_insertBt1(ms, base+idx, iend, mls, dictMode == ZSTD_extDict); | ||
|
r37513 | ms->nextToUpdate = target; | ||
} | ||||
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r40157 | void ZSTD_updateTree(ZSTD_matchState_t* ms, const BYTE* ip, const BYTE* iend) { | ||
ZSTD_updateTree_internal(ms, ip, iend, ms->cParams.searchLength, ZSTD_noDict); | ||||
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r37513 | } | ||
FORCE_INLINE_TEMPLATE | ||||
U32 ZSTD_insertBtAndGetAllMatches ( | ||||
|
r40157 | ZSTD_matchState_t* ms, | ||
const BYTE* const ip, const BYTE* const iLimit, const ZSTD_dictMode_e dictMode, | ||||
|
r37513 | U32 rep[ZSTD_REP_NUM], U32 const ll0, | ||
ZSTD_match_t* matches, const U32 lengthToBeat, U32 const mls /* template */) | ||||
{ | ||||
|
r40157 | const ZSTD_compressionParameters* const cParams = &ms->cParams; | ||
|
r37513 | U32 const sufficient_len = MIN(cParams->targetLength, ZSTD_OPT_NUM -1); | ||
const BYTE* const base = ms->window.base; | ||||
U32 const current = (U32)(ip-base); | ||||
U32 const hashLog = cParams->hashLog; | ||||
U32 const minMatch = (mls==3) ? 3 : 4; | ||||
U32* const hashTable = ms->hashTable; | ||||
size_t const h = ZSTD_hashPtr(ip, hashLog, mls); | ||||
U32 matchIndex = hashTable[h]; | ||||
U32* const bt = ms->chainTable; | ||||
U32 const btLog = cParams->chainLog - 1; | ||||
U32 const btMask= (1U << btLog) - 1; | ||||
size_t commonLengthSmaller=0, commonLengthLarger=0; | ||||
const BYTE* const dictBase = ms->window.dictBase; | ||||
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; | ||||
|
r40157 | U32 const matchLow = windowLow ? windowLow : 1; | ||
|
r37513 | U32* smallerPtr = bt + 2*(current&btMask); | ||
U32* largerPtr = bt + 2*(current&btMask) + 1; | ||||
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; | ||||
U32 nbCompares = 1U << cParams->searchLog; | ||||
|
r40157 | const ZSTD_matchState_t* dms = dictMode == ZSTD_dictMatchState ? ms->dictMatchState : NULL; | ||
const ZSTD_compressionParameters* const dmsCParams = | ||||
dictMode == ZSTD_dictMatchState ? &dms->cParams : NULL; | ||||
const BYTE* const dmsBase = dictMode == ZSTD_dictMatchState ? dms->window.base : NULL; | ||||
const BYTE* const dmsEnd = dictMode == ZSTD_dictMatchState ? dms->window.nextSrc : NULL; | ||||
U32 const dmsHighLimit = dictMode == ZSTD_dictMatchState ? (U32)(dmsEnd - dmsBase) : 0; | ||||
U32 const dmsLowLimit = dictMode == ZSTD_dictMatchState ? dms->window.lowLimit : 0; | ||||
U32 const dmsIndexDelta = dictMode == ZSTD_dictMatchState ? windowLow - dmsHighLimit : 0; | ||||
U32 const dmsHashLog = dictMode == ZSTD_dictMatchState ? dmsCParams->hashLog : hashLog; | ||||
U32 const dmsBtLog = dictMode == ZSTD_dictMatchState ? dmsCParams->chainLog - 1 : btLog; | ||||
U32 const dmsBtMask = dictMode == ZSTD_dictMatchState ? (1U << dmsBtLog) - 1 : 0; | ||||
U32 const dmsBtLow = dictMode == ZSTD_dictMatchState && dmsBtMask < dmsHighLimit - dmsLowLimit ? dmsHighLimit - dmsBtMask : dmsLowLimit; | ||||
|
r37513 | size_t bestLength = lengthToBeat-1; | ||
|
r40157 | DEBUGLOG(8, "ZSTD_insertBtAndGetAllMatches: current=%u", current); | ||
|
r37513 | |||
/* 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 */ | ||||
|
r40157 | const BYTE* const repMatch = dictMode == ZSTD_dictMatchState ? | ||
dmsBase + repIndex - dmsIndexDelta : | ||||
dictBase + repIndex; | ||||
|
r37513 | assert(current >= windowLow); | ||
|
r40157 | if ( dictMode == ZSTD_extDict | ||
|
r37513 | && ( ((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; | ||||
|
r40157 | } | ||
if (dictMode == ZSTD_dictMatchState | ||||
&& ( ((repOffset-1) /*intentional overflow*/ < current - (dmsLowLimit + dmsIndexDelta)) /* equivalent to `current > repIndex >= dmsLowLimit` */ | ||||
& ((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, dmsEnd, prefixStart) + minMatch; | ||||
|
r37513 | } } | ||
/* save longer solution */ | ||||
if (repLen > bestLength) { | ||||
|
r40157 | DEBUGLOG(8, "found repCode %u (ll0:%u, offset:%u) of length %u", | ||
repCode, ll0, repOffset, repLen); | ||||
|
r37513 | bestLength = repLen; | ||
matches[mnum].off = repCode - ll0; | ||||
matches[mnum].len = (U32)repLen; | ||||
mnum++; | ||||
if ( (repLen > sufficient_len) | ||||
| (ip+repLen == iLimit) ) { /* best possible */ | ||||
return mnum; | ||||
} } } } | ||||
/* HC3 match finder */ | ||||
if ((mls == 3) /*static*/ && (bestLength < mls)) { | ||||
U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3(ms, ip); | ||||
|
r40157 | if ((matchIndex3 >= matchLow) | ||
|
r37513 | & (current - matchIndex3 < (1<<18)) /*heuristic : longer distance likely too expensive*/ ) { | ||
size_t mlen; | ||||
|
r40157 | if ((dictMode == ZSTD_noDict) /*static*/ || (dictMode == ZSTD_dictMatchState) /*static*/ || (matchIndex3 >= dictLimit)) { | ||
|
r37513 | const BYTE* const match = base + matchIndex3; | ||
mlen = ZSTD_count(ip, match, iLimit); | ||||
} else { | ||||
const BYTE* const match = dictBase + matchIndex3; | ||||
mlen = ZSTD_count_2segments(ip, match, iLimit, dictEnd, prefixStart); | ||||
} | ||||
/* save best solution */ | ||||
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 */ | ||||
ms->nextToUpdate = current+1; /* skip insertion */ | ||||
return 1; | ||||
|
r40157 | } | ||
} | ||||
} | ||||
/* no dictMatchState lookup: dicts don't have a populated HC3 table */ | ||||
} | ||||
|
r37513 | |||
hashTable[h] = current; /* Update Hash Table */ | ||||
|
r40157 | while (nbCompares-- && (matchIndex >= matchLow)) { | ||
|
r37513 | 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); | ||||
|
r40157 | if ((dictMode == ZSTD_noDict) || (dictMode == ZSTD_dictMatchState) || (matchIndex+matchLength >= dictLimit)) { | ||
|
r37513 | assert(matchIndex+matchLength >= dictLimit); /* ensure the condition is correct when !extDict */ | ||
match = base + matchIndex; | ||||
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; /* prepare for match[matchLength] */ | ||||
} | ||||
if (matchLength > bestLength) { | ||||
|
r40157 | DEBUGLOG(8, "found match of length %u at distance %u (offCode=%u)", | ||
(U32)matchLength, current - matchIndex, current - matchIndex + ZSTD_REP_MOVE); | ||||
|
r37513 | assert(matchEndIdx > matchIndex); | ||
if (matchLength > matchEndIdx - matchIndex) | ||||
matchEndIdx = matchIndex + (U32)matchLength; | ||||
bestLength = matchLength; | ||||
matches[mnum].off = (current - matchIndex) + ZSTD_REP_MOVE; | ||||
matches[mnum].len = (U32)matchLength; | ||||
mnum++; | ||||
|
r40157 | if ( (matchLength > ZSTD_OPT_NUM) | ||
| (ip+matchLength == iLimit) /* equal : no way to know if inf or sup */) { | ||||
if (dictMode == ZSTD_dictMatchState) nbCompares = 0; /* break should also skip searching dms */ | ||||
break; /* drop, to preserve bt consistency (miss a little bit of compression) */ | ||||
|
r37513 | } | ||
} | ||||
if (match[matchLength] < ip[matchLength]) { | ||||
/* 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 candidate => larger than match, which was smaller than current */ | ||||
matchIndex = nextPtr[1]; /* new matchIndex, larger than previous, closer to current */ | ||||
} else { | ||||
*largerPtr = matchIndex; | ||||
commonLengthLarger = matchLength; | ||||
if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */ | ||||
largerPtr = nextPtr; | ||||
matchIndex = nextPtr[0]; | ||||
} } | ||||
*smallerPtr = *largerPtr = 0; | ||||
|
r40157 | if (dictMode == ZSTD_dictMatchState && nbCompares) { | ||
size_t const dmsH = ZSTD_hashPtr(ip, dmsHashLog, mls); | ||||
U32 dictMatchIndex = dms->hashTable[dmsH]; | ||||
const U32* const dmsBt = dms->chainTable; | ||||
commonLengthSmaller = commonLengthLarger = 0; | ||||
while (nbCompares-- && (dictMatchIndex > dmsLowLimit)) { | ||||
const U32* const nextPtr = dmsBt + 2*(dictMatchIndex & dmsBtMask); | ||||
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */ | ||||
const BYTE* match = dmsBase + dictMatchIndex; | ||||
matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iLimit, dmsEnd, prefixStart); | ||||
if (dictMatchIndex+matchLength >= dmsHighLimit) | ||||
match = base + dictMatchIndex + dmsIndexDelta; /* to prepare for next usage of match[matchLength] */ | ||||
if (matchLength > bestLength) { | ||||
matchIndex = dictMatchIndex + dmsIndexDelta; | ||||
DEBUGLOG(8, "found dms match of length %u at distance %u (offCode=%u)", | ||||
(U32)matchLength, current - matchIndex, current - matchIndex + ZSTD_REP_MOVE); | ||||
if (matchLength > matchEndIdx - matchIndex) | ||||
matchEndIdx = matchIndex + (U32)matchLength; | ||||
bestLength = matchLength; | ||||
matches[mnum].off = (current - matchIndex) + ZSTD_REP_MOVE; | ||||
matches[mnum].len = (U32)matchLength; | ||||
mnum++; | ||||
if ( (matchLength > ZSTD_OPT_NUM) | ||||
| (ip+matchLength == iLimit) /* equal : no way to know if inf or sup */) { | ||||
break; /* drop, to guarantee consistency (miss a little bit of compression) */ | ||||
} | ||||
} | ||||
if (dictMatchIndex <= dmsBtLow) { break; } /* beyond tree size, stop the search */ | ||||
if (match[matchLength] < ip[matchLength]) { | ||||
commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */ | ||||
dictMatchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */ | ||||
} else { | ||||
/* match is larger than current */ | ||||
commonLengthLarger = matchLength; | ||||
dictMatchIndex = nextPtr[0]; | ||||
} | ||||
} | ||||
} | ||||
|
r37513 | assert(matchEndIdx > current+8); | ||
ms->nextToUpdate = matchEndIdx - 8; /* skip repetitive patterns */ | ||||
return mnum; | ||||
} | ||||
FORCE_INLINE_TEMPLATE U32 ZSTD_BtGetAllMatches ( | ||||
|
r40157 | ZSTD_matchState_t* ms, | ||
const BYTE* ip, const BYTE* const iHighLimit, const ZSTD_dictMode_e dictMode, | ||||
|
r37513 | U32 rep[ZSTD_REP_NUM], U32 const ll0, | ||
ZSTD_match_t* matches, U32 const lengthToBeat) | ||||
{ | ||||
|
r40157 | const ZSTD_compressionParameters* const cParams = &ms->cParams; | ||
|
r37513 | U32 const matchLengthSearch = cParams->searchLength; | ||
|
r40157 | DEBUGLOG(8, "ZSTD_BtGetAllMatches"); | ||
|
r37513 | if (ip < ms->window.base + ms->nextToUpdate) return 0; /* skipped area */ | ||
|
r40157 | ZSTD_updateTree_internal(ms, ip, iHighLimit, matchLengthSearch, dictMode); | ||
|
r37513 | switch(matchLengthSearch) | ||
{ | ||||
|
r40157 | case 3 : return ZSTD_insertBtAndGetAllMatches(ms, ip, iHighLimit, dictMode, rep, ll0, matches, lengthToBeat, 3); | ||
|
r37513 | default : | ||
|
r40157 | 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); | ||||
|
r37513 | case 7 : | ||
|
r40157 | case 6 : return ZSTD_insertBtAndGetAllMatches(ms, ip, iHighLimit, dictMode, rep, ll0, matches, lengthToBeat, 6); | ||
|
r37513 | } | ||
} | ||||
/*-******************************* | ||||
* Optimal parser | ||||
*********************************/ | ||||
typedef struct repcodes_s { | ||||
U32 rep[3]; | ||||
} repcodes_t; | ||||
|
r40157 | static repcodes_t ZSTD_updateRep(U32 const rep[3], U32 const offset, U32 const ll0) | ||
|
r37513 | { | ||
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; | ||||
} | ||||
|
r40157 | static U32 ZSTD_totalLen(ZSTD_optimal_t sol) | ||
|
r37513 | { | ||
|
r40157 | return sol.litlen + sol.mlen; | ||
|
r37513 | } | ||
|
r40157 | FORCE_INLINE_TEMPLATE size_t | ||
ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms, | ||||
seqStore_t* seqStore, | ||||
U32 rep[ZSTD_REP_NUM], | ||||
const void* src, size_t srcSize, | ||||
const int optLevel, const ZSTD_dictMode_e dictMode) | ||||
|
r37513 | { | ||
optState_t* const optStatePtr = &ms->opt; | ||||
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 = ms->window.base; | ||||
const BYTE* const prefixStart = base + ms->window.dictLimit; | ||||
|
r40157 | const ZSTD_compressionParameters* const cParams = &ms->cParams; | ||
|
r37513 | |||
U32 const sufficient_len = MIN(cParams->targetLength, ZSTD_OPT_NUM -1); | ||||
U32 const minMatch = (cParams->searchLength == 3) ? 3 : 4; | ||||
ZSTD_optimal_t* const opt = optStatePtr->priceTable; | ||||
ZSTD_match_t* const matches = optStatePtr->matchTable; | ||||
|
r40157 | ZSTD_optimal_t lastSequence; | ||
|
r37513 | |||
/* init */ | ||||
DEBUGLOG(5, "ZSTD_compressBlock_opt_generic"); | ||||
|
r40157 | assert(optLevel <= 2); | ||
|
r37513 | ms->nextToUpdate3 = ms->nextToUpdate; | ||
|
r40157 | ZSTD_rescaleFreqs(optStatePtr, (const BYTE*)src, srcSize, optLevel); | ||
|
r37513 | ip += (ip==prefixStart); | ||
/* Match Loop */ | ||||
while (ip < ilimit) { | ||||
U32 cur, last_pos = 0; | ||||
/* find first match */ | ||||
{ U32 const litlen = (U32)(ip - anchor); | ||||
U32 const ll0 = !litlen; | ||||
|
r40157 | U32 const nbMatches = ZSTD_BtGetAllMatches(ms, ip, iend, dictMode, rep, ll0, matches, minMatch); | ||
|
r37513 | if (!nbMatches) { ip++; continue; } | ||
/* initialize opt[0] */ | ||||
{ U32 i ; for (i=0; i<ZSTD_REP_NUM; i++) opt[0].rep[i] = rep[i]; } | ||||
|
r40157 | opt[0].mlen = 0; /* means is_a_literal */ | ||
|
r37513 | opt[0].litlen = litlen; | ||
|
r40157 | opt[0].price = ZSTD_literalsContribution(anchor, litlen, optStatePtr, optLevel); | ||
|
r37513 | |||
/* large match -> immediate encoding */ | ||||
{ U32 const maxML = matches[nbMatches-1].len; | ||||
|
r40157 | U32 const maxOffset = matches[nbMatches-1].off; | ||
DEBUGLOG(6, "found %u matches of maxLength=%u and maxOffCode=%u at cPos=%u => start new serie", | ||||
nbMatches, maxML, maxOffset, (U32)(ip-prefixStart)); | ||||
|
r37513 | |||
if (maxML > sufficient_len) { | ||||
|
r40157 | lastSequence.litlen = litlen; | ||
lastSequence.mlen = maxML; | ||||
lastSequence.off = maxOffset; | ||||
DEBUGLOG(6, "large match (%u>%u), immediate encoding", | ||||
maxML, sufficient_len); | ||||
|
r37513 | cur = 0; | ||
|
r40157 | last_pos = ZSTD_totalLen(lastSequence); | ||
|
r37513 | goto _shortestPath; | ||
} } | ||||
/* set prices for first matches starting position == 0 */ | ||||
|
r40157 | { U32 const literalsPrice = opt[0].price + ZSTD_litLengthPrice(0, optStatePtr, optLevel); | ||
|
r37513 | U32 pos; | ||
U32 matchNb; | ||||
|
r40157 | for (pos = 1; pos < minMatch; pos++) { | ||
opt[pos].price = ZSTD_MAX_PRICE; /* mlen, litlen and price will be fixed during forward scanning */ | ||||
|
r37513 | } | ||
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++ ) { | ||||
|
r40157 | U32 const matchPrice = ZSTD_getMatchPrice(offset, pos, optStatePtr, optLevel); | ||
U32 const sequencePrice = literalsPrice + matchPrice; | ||||
DEBUGLOG(7, "rPos:%u => set initial price : %.2f", | ||||
pos, ZSTD_fCost(sequencePrice)); | ||||
|
r37513 | opt[pos].mlen = pos; | ||
opt[pos].off = offset; | ||||
opt[pos].litlen = litlen; | ||||
|
r40157 | opt[pos].price = sequencePrice; | ||
ZSTD_STATIC_ASSERT(sizeof(opt[pos].rep) == sizeof(repHistory)); | ||||
|
r37513 | memcpy(opt[pos].rep, &repHistory, sizeof(repHistory)); | ||
} } | ||||
last_pos = pos-1; | ||||
} | ||||
} | ||||
/* check further positions */ | ||||
for (cur = 1; cur <= last_pos; cur++) { | ||||
const BYTE* const inr = ip + cur; | ||||
assert(cur < ZSTD_OPT_NUM); | ||||
|
r40157 | DEBUGLOG(7, "cPos:%zi==rPos:%u", inr-istart, cur) | ||
|
r37513 | |||
/* Fix current position with one literal if cheaper */ | ||||
|
r40157 | { U32 const litlen = (opt[cur-1].mlen == 0) ? opt[cur-1].litlen + 1 : 1; | ||
int const price = opt[cur-1].price | ||||
+ ZSTD_rawLiteralsCost(ip+cur-1, 1, optStatePtr, optLevel) | ||||
+ ZSTD_litLengthPrice(litlen, optStatePtr, optLevel) | ||||
- ZSTD_litLengthPrice(litlen-1, optStatePtr, optLevel); | ||||
|
r37513 | assert(price < 1000000000); /* overflow check */ | ||
if (price <= opt[cur].price) { | ||||
|
r40157 | DEBUGLOG(7, "cPos:%zi==rPos:%u : better price (%.2f<=%.2f) using literal (ll==%u) (hist:%u,%u,%u)", | ||
inr-istart, cur, ZSTD_fCost(price), ZSTD_fCost(opt[cur].price), litlen, | ||||
opt[cur-1].rep[0], opt[cur-1].rep[1], opt[cur-1].rep[2]); | ||||
opt[cur].mlen = 0; | ||||
|
r37513 | opt[cur].off = 0; | ||
opt[cur].litlen = litlen; | ||||
opt[cur].price = price; | ||||
memcpy(opt[cur].rep, opt[cur-1].rep, sizeof(opt[cur].rep)); | ||||
|
r40157 | } 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), | ||||
opt[cur].rep[0], opt[cur].rep[1], opt[cur].rep[2]); | ||||
} | ||||
} | ||||
|
r37513 | |||
/* last match must start at a minimum distance of 8 from oend */ | ||||
if (inr > ilimit) continue; | ||||
if (cur == last_pos) break; | ||||
|
r40157 | if ( (optLevel==0) /*static_test*/ | ||
&& (opt[cur+1].price <= opt[cur].price + (BITCOST_MULTIPLIER/2)) ) { | ||||
DEBUGLOG(7, "move to next rPos:%u : price is <=", cur+1); | ||||
|
r37513 | continue; /* skip unpromising positions; about ~+6% speed, -0.01 ratio */ | ||
|
r40157 | } | ||
|
r37513 | |||
|
r40157 | { U32 const ll0 = (opt[cur].mlen != 0); | ||
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); | ||||
|
r37513 | U32 matchNb; | ||
|
r40157 | if (!nbMatches) { | ||
DEBUGLOG(7, "rPos:%u : no match found", cur); | ||||
continue; | ||||
} | ||||
|
r37513 | |||
{ U32 const maxML = matches[nbMatches-1].len; | ||||
|
r40157 | DEBUGLOG(7, "cPos:%zi==rPos:%u, found %u matches, of maxLength=%u", | ||
inr-istart, cur, nbMatches, maxML); | ||||
|
r37513 | |||
if ( (maxML > sufficient_len) | ||||
|
r40157 | || (cur + maxML >= ZSTD_OPT_NUM) ) { | ||
lastSequence.mlen = maxML; | ||||
lastSequence.off = matches[nbMatches-1].off; | ||||
lastSequence.litlen = litlen; | ||||
cur -= (opt[cur].mlen==0) ? opt[cur].litlen : 0; /* last sequence is actually only literals, fix cur to last match - note : may underflow, in which case, it's first sequence, and it's okay */ | ||||
last_pos = cur + ZSTD_totalLen(lastSequence); | ||||
if (cur > ZSTD_OPT_NUM) cur = 0; /* underflow => first match */ | ||||
|
r37513 | goto _shortestPath; | ||
|
r40157 | } } | ||
|
r37513 | |||
/* 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; | ||||
|
r40157 | DEBUGLOG(7, "testing match %u => offCode=%4u, mlen=%2u, llen=%2u", | ||
|
r37513 | matchNb, matches[matchNb].off, lastML, litlen); | ||
|
r40157 | for (mlen = lastML; mlen >= startML; mlen--) { /* scan downward */ | ||
|
r37513 | U32 const pos = cur + mlen; | ||
int const price = basePrice + ZSTD_getMatchPrice(offset, mlen, optStatePtr, optLevel); | ||||
if ((pos > last_pos) || (price < opt[pos].price)) { | ||||
|
r40157 | DEBUGLOG(7, "rPos:%u (ml=%2u) => new better price (%.2f<%.2f)", | ||
pos, mlen, ZSTD_fCost(price), ZSTD_fCost(opt[pos].price)); | ||||
while (last_pos < pos) { opt[last_pos+1].price = ZSTD_MAX_PRICE; last_pos++; } /* fill empty positions */ | ||||
|
r37513 | opt[pos].mlen = mlen; | ||
opt[pos].off = offset; | ||||
opt[pos].litlen = litlen; | ||||
opt[pos].price = price; | ||||
|
r40157 | ZSTD_STATIC_ASSERT(sizeof(opt[pos].rep) == sizeof(repHistory)); | ||
|
r37513 | memcpy(opt[pos].rep, &repHistory, sizeof(repHistory)); | ||
} else { | ||||
|
r40157 | DEBUGLOG(7, "rPos:%u (ml=%2u) => new price is worse (%.2f>=%.2f)", | ||
pos, mlen, ZSTD_fCost(price), ZSTD_fCost(opt[pos].price)); | ||||
if (optLevel==0) break; /* early update abort; gets ~+10% speed for about -0.01 ratio loss */ | ||||
|
r37513 | } | ||
} } } | ||||
} /* for (cur = 1; cur <= last_pos; cur++) */ | ||||
|
r40157 | lastSequence = opt[last_pos]; | ||
cur = last_pos > ZSTD_totalLen(lastSequence) ? last_pos - ZSTD_totalLen(lastSequence) : 0; /* single sequence, and it starts before `ip` */ | ||||
assert(cur < ZSTD_OPT_NUM); /* control overflow*/ | ||||
|
r37513 | |||
_shortestPath: /* cur, last_pos, best_mlen, best_off have to be set */ | ||||
|
r40157 | assert(opt[0].mlen == 0); | ||
{ U32 const storeEnd = cur + 1; | ||||
U32 storeStart = storeEnd; | ||||
U32 seqPos = cur; | ||||
|
r37513 | |||
|
r40157 | DEBUGLOG(6, "start reverse traversal (last_pos:%u, cur:%u)", | ||
last_pos, cur); (void)last_pos; | ||||
assert(storeEnd < ZSTD_OPT_NUM); | ||||
DEBUGLOG(6, "last sequence copied into pos=%u (llen=%u,mlen=%u,ofc=%u)", | ||||
storeEnd, lastSequence.litlen, lastSequence.mlen, lastSequence.off); | ||||
opt[storeEnd] = lastSequence; | ||||
while (seqPos > 0) { | ||||
U32 const backDist = ZSTD_totalLen(opt[seqPos]); | ||||
storeStart--; | ||||
DEBUGLOG(6, "sequence from rPos=%u copied into pos=%u (llen=%u,mlen=%u,ofc=%u)", | ||||
seqPos, storeStart, opt[seqPos].litlen, opt[seqPos].mlen, opt[seqPos].off); | ||||
opt[storeStart] = opt[seqPos]; | ||||
seqPos = (seqPos > backDist) ? seqPos - backDist : 0; | ||||
} | ||||
|
r37513 | |||
|
r40157 | /* save sequences */ | ||
DEBUGLOG(6, "sending selected sequences into seqStore") | ||||
{ U32 storePos; | ||||
for (storePos=storeStart; storePos <= storeEnd; storePos++) { | ||||
U32 const llen = opt[storePos].litlen; | ||||
U32 const mlen = opt[storePos].mlen; | ||||
U32 const offCode = opt[storePos].off; | ||||
U32 const advance = llen + mlen; | ||||
DEBUGLOG(6, "considering seq starting at %zi, llen=%u, mlen=%u", | ||||
anchor - istart, llen, mlen); | ||||
if (mlen==0) { /* only literals => must be last "sequence", actually starting a new stream of sequences */ | ||||
assert(storePos == storeEnd); /* must be last sequence */ | ||||
ip = anchor + llen; /* last "sequence" is a bunch of literals => don't progress anchor */ | ||||
continue; /* will finish */ | ||||
} | ||||
|
r37513 | |||
|
r40157 | /* repcodes update : like ZSTD_updateRep(), but update in place */ | ||
if (offCode >= ZSTD_REP_NUM) { /* full offset */ | ||||
rep[2] = rep[1]; | ||||
|
r37513 | rep[1] = rep[0]; | ||
|
r40157 | 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; | ||||
} } | ||||
|
r37513 | |||
|
r40157 | assert(anchor + llen <= iend); | ||
ZSTD_updateStats(optStatePtr, llen, anchor, offCode, mlen); | ||||
ZSTD_storeSeq(seqStore, llen, anchor, offCode, mlen-MINMATCH); | ||||
anchor += advance; | ||||
ip = anchor; | ||||
} } | ||||
ZSTD_setBasePrices(optStatePtr, optLevel); | ||||
} | ||||
|
r37513 | } /* while (ip < ilimit) */ | ||
/* Return the last literals size */ | ||||
return iend - anchor; | ||||
} | ||||
size_t ZSTD_compressBlock_btopt( | ||||
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], | ||||
|
r40157 | const void* src, size_t srcSize) | ||
|
r37513 | { | ||
DEBUGLOG(5, "ZSTD_compressBlock_btopt"); | ||||
|
r40157 | return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_noDict); | ||
} | ||||
/* used in 2-pass strategy */ | ||||
static U32 ZSTD_upscaleStat(U32* table, U32 lastEltIndex, int bonus) | ||||
{ | ||||
U32 s, sum=0; | ||||
assert(ZSTD_FREQ_DIV+bonus > 0); | ||||
for (s=0; s<=lastEltIndex; s++) { | ||||
table[s] <<= ZSTD_FREQ_DIV+bonus; | ||||
table[s]--; | ||||
sum += table[s]; | ||||
} | ||||
return sum; | ||||
} | ||||
/* used in 2-pass strategy */ | ||||
MEM_STATIC void ZSTD_upscaleStats(optState_t* optPtr) | ||||
{ | ||||
optPtr->litSum = ZSTD_upscaleStat(optPtr->litFreq, MaxLit, 0); | ||||
optPtr->litLengthSum = ZSTD_upscaleStat(optPtr->litLengthFreq, MaxLL, 1); | ||||
optPtr->matchLengthSum = ZSTD_upscaleStat(optPtr->matchLengthFreq, MaxML, 1); | ||||
optPtr->offCodeSum = ZSTD_upscaleStat(optPtr->offCodeFreq, MaxOff, 1); | ||||
|
r37513 | } | ||
size_t ZSTD_compressBlock_btultra( | ||||
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], | ||||
|
r40157 | const void* src, size_t srcSize) | ||
|
r37513 | { | ||
|
r40157 | DEBUGLOG(5, "ZSTD_compressBlock_btultra (srcSize=%zu)", srcSize); | ||
#if 0 | ||||
/* 2-pass strategy (disabled) | ||||
* this strategy makes a first pass over first block to collect statistics | ||||
* and seed next round's statistics with it. | ||||
* The compression ratio gain is generally small (~0.5% on first block), | ||||
* the cost is 2x cpu time on first block. */ | ||||
assert(srcSize <= ZSTD_BLOCKSIZE_MAX); | ||||
if ( (ms->opt.litLengthSum==0) /* first block */ | ||||
&& (seqStore->sequences == seqStore->sequencesStart) /* no ldm */ | ||||
&& (ms->window.dictLimit == ms->window.lowLimit) ) { /* no dictionary */ | ||||
U32 tmpRep[ZSTD_REP_NUM]; | ||||
DEBUGLOG(5, "ZSTD_compressBlock_btultra: first block: collecting statistics"); | ||||
assert(ms->nextToUpdate >= ms->window.dictLimit | ||||
&& ms->nextToUpdate <= ms->window.dictLimit + 1); | ||||
memcpy(tmpRep, rep, sizeof(tmpRep)); | ||||
ZSTD_compressBlock_opt_generic(ms, seqStore, tmpRep, src, srcSize, 2 /*optLevel*/, ZSTD_noDict); /* generate stats into ms->opt*/ | ||||
ZSTD_resetSeqStore(seqStore); | ||||
/* invalidate first scan from history */ | ||||
ms->window.base -= srcSize; | ||||
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); | ||||
} | ||||
#endif | ||||
return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_noDict); | ||||
} | ||||
size_t ZSTD_compressBlock_btopt_dictMatchState( | ||||
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], | ||||
const void* src, size_t srcSize) | ||||
{ | ||||
return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_dictMatchState); | ||||
} | ||||
size_t ZSTD_compressBlock_btultra_dictMatchState( | ||||
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], | ||||
const void* src, size_t srcSize) | ||||
{ | ||||
return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_dictMatchState); | ||||
|
r37513 | } | ||
size_t ZSTD_compressBlock_btopt_extDict( | ||||
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], | ||||
|
r40157 | const void* src, size_t srcSize) | ||
|
r37513 | { | ||
|
r40157 | return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_extDict); | ||
|
r37513 | } | ||
size_t ZSTD_compressBlock_btultra_extDict( | ||||
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], | ||||
|
r40157 | const void* src, size_t srcSize) | ||
|
r37513 | { | ||
|
r40157 | return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_extDict); | ||
|
r37513 | } | ||