1050 lines
45 KiB
C
1050 lines
45 KiB
C
/*
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* Copyright (c) 2016-present, Przemyslaw Skibinski, Yann Collet, Facebook, Inc.
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* All rights reserved.
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*
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* This source code is licensed under both the BSD-style license (found in the
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* LICENSE file in the root directory of this source tree) and the GPLv2 (found
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* in the COPYING file in the root directory of this source tree).
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* You may select, at your option, one of the above-listed licenses.
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*/
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#include "zstd_compress_internal.h"
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#include "zstd_opt.h"
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#define ZSTD_LITFREQ_ADD 2 /* scaling factor for litFreq, so that frequencies adapt faster to new stats */
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#define ZSTD_FREQ_DIV 4 /* log factor when using previous stats to init next stats */
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#define ZSTD_MAX_PRICE (1<<30)
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/*-*************************************
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* Price functions for optimal parser
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***************************************/
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static void ZSTD_setLog2Prices(optState_t* optPtr)
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{
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optPtr->log2litSum = ZSTD_highbit32(optPtr->litSum+1);
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optPtr->log2litLengthSum = ZSTD_highbit32(optPtr->litLengthSum+1);
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optPtr->log2matchLengthSum = ZSTD_highbit32(optPtr->matchLengthSum+1);
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optPtr->log2offCodeSum = ZSTD_highbit32(optPtr->offCodeSum+1);
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}
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static void ZSTD_rescaleFreqs(optState_t* const optPtr,
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const BYTE* const src, size_t const srcSize)
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{
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optPtr->priceType = zop_dynamic;
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if (optPtr->litLengthSum == 0) { /* first block : init */
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if (srcSize <= 1024) /* heuristic */
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optPtr->priceType = zop_predef;
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assert(optPtr->symbolCosts != NULL);
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if (optPtr->symbolCosts->hufCTable_repeatMode == HUF_repeat_valid) { /* huffman table presumed generated by dictionary */
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if (srcSize <= 8192) /* heuristic */
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optPtr->priceType = zop_static;
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else {
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assert(optPtr->priceType == zop_dynamic);
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}
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assert(optPtr->litFreq != NULL);
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assert(optPtr->symbolCosts != NULL);
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optPtr->litSum = 0;
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{ unsigned lit;
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for (lit=0; lit<=MaxLit; lit++) {
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U32 const scaleLog = 12; /* scale to 4K */
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U32 const bitCost = HUF_getNbBits(optPtr->symbolCosts->hufCTable, lit);
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assert(bitCost < scaleLog);
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optPtr->litFreq[lit] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
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optPtr->litSum += optPtr->litFreq[lit];
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} }
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{ unsigned ll;
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FSE_CState_t llstate;
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FSE_initCState(&llstate, optPtr->symbolCosts->litlengthCTable);
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optPtr->litLengthSum = 0;
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for (ll=0; ll<=MaxLL; ll++) {
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U32 const scaleLog = 11; /* scale to 2K */
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U32 const bitCost = FSE_getMaxNbBits(llstate.symbolTT, ll);
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assert(bitCost < scaleLog);
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optPtr->litLengthFreq[ll] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
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optPtr->litLengthSum += optPtr->litLengthFreq[ll];
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} }
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{ unsigned ml;
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FSE_CState_t mlstate;
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FSE_initCState(&mlstate, optPtr->symbolCosts->matchlengthCTable);
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optPtr->matchLengthSum = 0;
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for (ml=0; ml<=MaxML; ml++) {
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U32 const scaleLog = 11; /* scale to 2K */
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U32 const bitCost = FSE_getMaxNbBits(mlstate.symbolTT, ml);
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assert(bitCost < scaleLog);
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optPtr->matchLengthFreq[ml] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
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optPtr->matchLengthSum += optPtr->matchLengthFreq[ml];
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} }
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{ unsigned of;
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FSE_CState_t ofstate;
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FSE_initCState(&ofstate, optPtr->symbolCosts->offcodeCTable);
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optPtr->offCodeSum = 0;
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for (of=0; of<=MaxOff; of++) {
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U32 const scaleLog = 11; /* scale to 2K */
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U32 const bitCost = FSE_getMaxNbBits(ofstate.symbolTT, of);
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assert(bitCost < scaleLog);
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optPtr->offCodeFreq[of] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
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optPtr->offCodeSum += optPtr->offCodeFreq[of];
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} }
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} else { /* not a dictionary */
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assert(optPtr->litFreq != NULL);
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optPtr->litSum = 0;
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{ unsigned lit = MaxLit;
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FSE_count(optPtr->litFreq, &lit, src, srcSize); /* use raw first block to init statistics */
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for (lit=0; lit<=MaxLit; lit++) {
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optPtr->litFreq[lit] = 1 + (optPtr->litFreq[lit] >> (ZSTD_FREQ_DIV+1));
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optPtr->litSum += optPtr->litFreq[lit];
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} }
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{ unsigned ll;
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for (ll=0; ll<=MaxLL; ll++)
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optPtr->litLengthFreq[ll] = 1;
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optPtr->litLengthSum = MaxLL+1;
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}
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{ unsigned ml;
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for (ml=0; ml<=MaxML; ml++)
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optPtr->matchLengthFreq[ml] = 1;
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optPtr->matchLengthSum = MaxML+1;
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}
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{ unsigned of;
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for (of=0; of<=MaxOff; of++)
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optPtr->offCodeFreq[of] = 1;
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optPtr->offCodeSum = MaxOff+1;
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}
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}
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} else { /* new block : re-use previous statistics, scaled down */
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unsigned u;
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optPtr->litSum = 0;
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for (u=0; u<=MaxLit; u++) {
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optPtr->litFreq[u] = 1 + (optPtr->litFreq[u] >> (ZSTD_FREQ_DIV+1));
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optPtr->litSum += optPtr->litFreq[u];
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}
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optPtr->litLengthSum = 0;
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for (u=0; u<=MaxLL; u++) {
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optPtr->litLengthFreq[u] = 1 + (optPtr->litLengthFreq[u] >> ZSTD_FREQ_DIV);
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optPtr->litLengthSum += optPtr->litLengthFreq[u];
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}
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optPtr->matchLengthSum = 0;
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for (u=0; u<=MaxML; u++) {
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optPtr->matchLengthFreq[u] = 1 + (optPtr->matchLengthFreq[u] >> ZSTD_FREQ_DIV);
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optPtr->matchLengthSum += optPtr->matchLengthFreq[u];
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}
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optPtr->offCodeSum = 0;
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for (u=0; u<=MaxOff; u++) {
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optPtr->offCodeFreq[u] = 1 + (optPtr->offCodeFreq[u] >> ZSTD_FREQ_DIV);
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optPtr->offCodeSum += optPtr->offCodeFreq[u];
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}
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}
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ZSTD_setLog2Prices(optPtr);
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}
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#if 1 /* approximation at bit level */
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# define BITCOST_ACCURACY 0
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# define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY)
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# define BITCOST_SYMBOL(t,l,s) ((void)l, FSE_getMaxNbBits(t,s)*BITCOST_MULTIPLIER)
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#else /* fractional bit accuracy */
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# define BITCOST_ACCURACY 8
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# define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY)
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# define BITCOST_SYMBOL(t,l,s) FSE_bitCost(t,l,s,BITCOST_ACCURACY)
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#endif
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MEM_STATIC double
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ZSTD_fCost(U32 price)
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{
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return (double)price / (BITCOST_MULTIPLIER*8);
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}
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/* ZSTD_rawLiteralsCost() :
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* cost of literals (only) in specified segment (which length can be 0).
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* does not include cost of literalLength symbol */
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static U32 ZSTD_rawLiteralsCost(const BYTE* const literals, U32 const litLength,
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const optState_t* const optPtr)
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{
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if (litLength == 0) return 0;
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if (optPtr->priceType == zop_predef) return (litLength*6); /* 6 bit per literal - no statistic used */
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if (optPtr->priceType == zop_static) {
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U32 u, cost;
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assert(optPtr->symbolCosts != NULL);
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assert(optPtr->symbolCosts->hufCTable_repeatMode == HUF_repeat_valid);
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for (u=0, cost=0; u < litLength; u++)
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cost += HUF_getNbBits(optPtr->symbolCosts->hufCTable, literals[u]);
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return cost * BITCOST_MULTIPLIER;
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}
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/* dynamic statistics */
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{ U32 u;
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U32 cost = litLength * optPtr->log2litSum;
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for (u=0; u < litLength; u++)
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cost -= ZSTD_highbit32(optPtr->litFreq[literals[u]]+1);
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return cost * BITCOST_MULTIPLIER;
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}
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}
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/* ZSTD_litLengthPrice() :
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* cost of literalLength symbol */
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static U32 ZSTD_litLengthPrice(U32 const litLength, const optState_t* const optPtr)
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{
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if (optPtr->priceType == zop_static) {
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U32 const llCode = ZSTD_LLcode(litLength);
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FSE_CState_t cstate;
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FSE_initCState(&cstate, optPtr->symbolCosts->litlengthCTable);
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{ U32 const price = LL_bits[llCode]*BITCOST_MULTIPLIER + BITCOST_SYMBOL(cstate.symbolTT, cstate.stateLog, llCode);
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DEBUGLOG(8, "ZSTD_litLengthPrice: ll=%u, bitCost=%.2f", litLength, (double)price / BITCOST_MULTIPLIER);
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return price;
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} }
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if (optPtr->priceType == zop_predef) return ZSTD_highbit32((U32)litLength+1);
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/* dynamic statistics */
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{ U32 const llCode = ZSTD_LLcode(litLength);
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return (LL_bits[llCode] + optPtr->log2litLengthSum - ZSTD_highbit32(optPtr->litLengthFreq[llCode]+1)) * BITCOST_MULTIPLIER;
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}
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}
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/* ZSTD_litLengthPrice() :
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* cost of the literal part of a sequence,
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* including literals themselves, and literalLength symbol */
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static U32 ZSTD_fullLiteralsCost(const BYTE* const literals, U32 const litLength,
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const optState_t* const optPtr)
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{
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return ZSTD_rawLiteralsCost(literals, litLength, optPtr)
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+ ZSTD_litLengthPrice(litLength, optPtr);
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}
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/* ZSTD_litLengthContribution() :
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* @return ( cost(litlength) - cost(0) )
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* this value can then be added to rawLiteralsCost()
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* to provide a cost which is directly comparable to a match ending at same position */
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static int ZSTD_litLengthContribution(U32 const litLength, const optState_t* const optPtr)
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{
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if (optPtr->priceType == zop_static) {
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U32 const llCode = ZSTD_LLcode(litLength);
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FSE_CState_t cstate;
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FSE_initCState(&cstate, optPtr->symbolCosts->litlengthCTable);
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return (int)(LL_bits[llCode] * BITCOST_MULTIPLIER)
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+ BITCOST_SYMBOL(cstate.symbolTT, cstate.stateLog, llCode)
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- BITCOST_SYMBOL(cstate.symbolTT, cstate.stateLog, 0);
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}
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if (optPtr->priceType >= zop_predef) return ZSTD_highbit32(litLength+1);
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/* dynamic statistics */
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{ U32 const llCode = ZSTD_LLcode(litLength);
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int const contribution = (LL_bits[llCode]
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+ ZSTD_highbit32(optPtr->litLengthFreq[0]+1)
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- ZSTD_highbit32(optPtr->litLengthFreq[llCode]+1))
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* BITCOST_MULTIPLIER;
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#if 1
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return contribution;
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#else
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return MAX(0, contribution); /* sometimes better, sometimes not ... */
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#endif
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}
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}
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/* ZSTD_literalsContribution() :
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* creates a fake cost for the literals part of a sequence
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* which can be compared to the ending cost of a match
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* should a new match start at this position */
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static int ZSTD_literalsContribution(const BYTE* const literals, U32 const litLength,
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const optState_t* const optPtr)
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{
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int const contribution = ZSTD_rawLiteralsCost(literals, litLength, optPtr)
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+ ZSTD_litLengthContribution(litLength, optPtr);
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return contribution;
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}
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/* ZSTD_getMatchPrice() :
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* Provides the cost of the match part (offset + matchLength) of a sequence
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* Must be combined with ZSTD_fullLiteralsCost() to get the full cost of a sequence.
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* optLevel: when <2, favors small offset for decompression speed (improved cache efficiency) */
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FORCE_INLINE_TEMPLATE U32
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ZSTD_getMatchPrice(U32 const offset, U32 const matchLength,
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const optState_t* const optPtr,
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int const optLevel)
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{
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U32 price;
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U32 const offCode = ZSTD_highbit32(offset+1);
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U32 const mlBase = matchLength - MINMATCH;
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assert(matchLength >= MINMATCH);
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if (optPtr->priceType == zop_static) {
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U32 const mlCode = ZSTD_MLcode(mlBase);
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FSE_CState_t mlstate, offstate;
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FSE_initCState(&mlstate, optPtr->symbolCosts->matchlengthCTable);
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FSE_initCState(&offstate, optPtr->symbolCosts->offcodeCTable);
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return BITCOST_SYMBOL(offstate.symbolTT, offstate.stateLog, offCode) + offCode*BITCOST_MULTIPLIER
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+ BITCOST_SYMBOL(mlstate.symbolTT, mlstate.stateLog, mlCode) + ML_bits[mlCode]*BITCOST_MULTIPLIER;
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}
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if (optPtr->priceType == zop_predef) /* fixed scheme, do not use statistics */
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return ZSTD_highbit32(mlBase+1) + 16 + offCode;
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/* dynamic statistics */
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price = offCode + optPtr->log2offCodeSum - ZSTD_highbit32(optPtr->offCodeFreq[offCode]+1);
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if ((optLevel<2) /*static*/ && offCode >= 20) price += (offCode-19)*2; /* handicap for long distance offsets, favor decompression speed */
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/* match Length */
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{ U32 const mlCode = ZSTD_MLcode(mlBase);
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price += ML_bits[mlCode] + optPtr->log2matchLengthSum - ZSTD_highbit32(optPtr->matchLengthFreq[mlCode]+1);
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}
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DEBUGLOG(8, "ZSTD_getMatchPrice(ml:%u) = %u", matchLength, price);
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return price * BITCOST_MULTIPLIER;
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}
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static void ZSTD_updateStats(optState_t* const optPtr,
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U32 litLength, const BYTE* literals,
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U32 offsetCode, U32 matchLength)
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{
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/* literals */
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{ U32 u;
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for (u=0; u < litLength; u++)
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optPtr->litFreq[literals[u]] += ZSTD_LITFREQ_ADD;
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optPtr->litSum += litLength*ZSTD_LITFREQ_ADD;
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}
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/* literal Length */
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{ U32 const llCode = ZSTD_LLcode(litLength);
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optPtr->litLengthFreq[llCode]++;
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optPtr->litLengthSum++;
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}
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/* match offset code (0-2=>repCode; 3+=>offset+2) */
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{ U32 const offCode = ZSTD_highbit32(offsetCode+1);
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assert(offCode <= MaxOff);
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optPtr->offCodeFreq[offCode]++;
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optPtr->offCodeSum++;
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}
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/* match Length */
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{ U32 const mlBase = matchLength - MINMATCH;
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U32 const mlCode = ZSTD_MLcode(mlBase);
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optPtr->matchLengthFreq[mlCode]++;
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optPtr->matchLengthSum++;
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}
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}
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/* ZSTD_readMINMATCH() :
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* function safe only for comparisons
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* assumption : memPtr must be at least 4 bytes before end of buffer */
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MEM_STATIC U32 ZSTD_readMINMATCH(const void* memPtr, U32 length)
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{
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switch (length)
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{
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default :
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case 4 : return MEM_read32(memPtr);
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case 3 : if (MEM_isLittleEndian())
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return MEM_read32(memPtr)<<8;
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else
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return MEM_read32(memPtr)>>8;
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}
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}
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/* Update hashTable3 up to ip (excluded)
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Assumption : always within prefix (i.e. not within extDict) */
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static U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_matchState_t* ms, const BYTE* const ip)
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{
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U32* const hashTable3 = ms->hashTable3;
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U32 const hashLog3 = ms->hashLog3;
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const BYTE* const base = ms->window.base;
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U32 idx = ms->nextToUpdate3;
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U32 const target = ms->nextToUpdate3 = (U32)(ip - base);
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size_t const hash3 = ZSTD_hash3Ptr(ip, hashLog3);
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assert(hashLog3 > 0);
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while(idx < target) {
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hashTable3[ZSTD_hash3Ptr(base+idx, hashLog3)] = idx;
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idx++;
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}
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return hashTable3[hash3];
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}
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/*-*************************************
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* Binary Tree search
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***************************************/
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/** ZSTD_insertBt1() : add one or multiple positions to tree.
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* ip : assumed <= iend-8 .
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* @return : nb of positions added */
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static U32 ZSTD_insertBt1(
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ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
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const BYTE* const ip, const BYTE* const iend,
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U32 const mls, U32 const extDict)
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{
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U32* const hashTable = ms->hashTable;
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U32 const hashLog = cParams->hashLog;
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size_t const h = ZSTD_hashPtr(ip, hashLog, mls);
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U32* const bt = ms->chainTable;
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U32 const btLog = cParams->chainLog - 1;
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U32 const btMask = (1 << btLog) - 1;
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U32 matchIndex = hashTable[h];
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size_t commonLengthSmaller=0, commonLengthLarger=0;
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const BYTE* const base = ms->window.base;
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const BYTE* const dictBase = ms->window.dictBase;
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const U32 dictLimit = ms->window.dictLimit;
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const BYTE* const dictEnd = dictBase + dictLimit;
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const BYTE* const prefixStart = base + dictLimit;
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const BYTE* match;
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const U32 current = (U32)(ip-base);
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const U32 btLow = btMask >= current ? 0 : current - btMask;
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U32* smallerPtr = bt + 2*(current&btMask);
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U32* largerPtr = smallerPtr + 1;
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U32 dummy32; /* to be nullified at the end */
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U32 const windowLow = ms->window.lowLimit;
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U32 matchEndIdx = current+8+1;
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size_t bestLength = 8;
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U32 nbCompares = 1U << cParams->searchLog;
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#ifdef ZSTD_C_PREDICT
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U32 predictedSmall = *(bt + 2*((current-1)&btMask) + 0);
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U32 predictedLarge = *(bt + 2*((current-1)&btMask) + 1);
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predictedSmall += (predictedSmall>0);
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predictedLarge += (predictedLarge>0);
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#endif /* ZSTD_C_PREDICT */
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DEBUGLOG(8, "ZSTD_insertBt1 (%u)", current);
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assert(ip <= iend-8); /* required for h calculation */
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hashTable[h] = current; /* Update Hash Table */
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while (nbCompares-- && (matchIndex > windowLow)) {
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U32* const nextPtr = bt + 2*(matchIndex & btMask);
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size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
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assert(matchIndex < current);
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#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
|
|
|
|
if ((!extDict) || (matchIndex+matchLength >= dictLimit)) {
|
|
assert(matchIndex+matchLength >= dictLimit); /* might be wrong if extDict is incorrectly set to 0 */
|
|
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(
|
|
ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
|
|
const BYTE* const ip, const BYTE* const iend,
|
|
const U32 mls, const U32 extDict)
|
|
{
|
|
const BYTE* const base = ms->window.base;
|
|
U32 const target = (U32)(ip - base);
|
|
U32 idx = ms->nextToUpdate;
|
|
DEBUGLOG(8, "ZSTD_updateTree_internal, from %u to %u (extDict:%u)",
|
|
idx, target, extDict);
|
|
|
|
while(idx < target)
|
|
idx += ZSTD_insertBt1(ms, cParams, base+idx, iend, mls, extDict);
|
|
ms->nextToUpdate = target;
|
|
}
|
|
|
|
void ZSTD_updateTree(
|
|
ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
|
|
const BYTE* ip, const BYTE* iend)
|
|
{
|
|
ZSTD_updateTree_internal(ms, cParams, ip, iend, cParams->searchLength, 0 /*extDict*/);
|
|
}
|
|
|
|
FORCE_INLINE_TEMPLATE
|
|
U32 ZSTD_insertBtAndGetAllMatches (
|
|
ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
|
|
const BYTE* const ip, const BYTE* const iLimit, int const extDict,
|
|
U32 rep[ZSTD_REP_NUM], U32 const ll0,
|
|
ZSTD_match_t* matches, const U32 lengthToBeat, U32 const mls /* template */)
|
|
{
|
|
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;
|
|
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;
|
|
|
|
size_t bestLength = lengthToBeat-1;
|
|
DEBUGLOG(8, "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;
|
|
} } } }
|
|
|
|
/* HC3 match finder */
|
|
if ((mls == 3) /*static*/ && (bestLength < mls)) {
|
|
U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3(ms, ip);
|
|
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 {
|
|
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;
|
|
} } } }
|
|
|
|
hashTable[h] = current; /* Update Hash Table */
|
|
|
|
while (nbCompares-- && (matchIndex > windowLow)) {
|
|
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;
|
|
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) {
|
|
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 = (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 preserve bt consistency (miss a little bit of compression) */
|
|
}
|
|
}
|
|
|
|
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;
|
|
|
|
assert(matchEndIdx > current+8);
|
|
ms->nextToUpdate = matchEndIdx - 8; /* skip repetitive patterns */
|
|
return mnum;
|
|
}
|
|
|
|
|
|
FORCE_INLINE_TEMPLATE U32 ZSTD_BtGetAllMatches (
|
|
ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
|
|
const BYTE* ip, const BYTE* const iHighLimit, int const extDict,
|
|
U32 rep[ZSTD_REP_NUM], U32 const ll0,
|
|
ZSTD_match_t* matches, U32 const lengthToBeat)
|
|
{
|
|
U32 const matchLengthSearch = cParams->searchLength;
|
|
DEBUGLOG(8, "ZSTD_BtGetAllMatches");
|
|
if (ip < ms->window.base + ms->nextToUpdate) return 0; /* skipped area */
|
|
ZSTD_updateTree_internal(ms, cParams, ip, iHighLimit, matchLengthSearch, extDict);
|
|
switch(matchLengthSearch)
|
|
{
|
|
case 3 : return ZSTD_insertBtAndGetAllMatches(ms, cParams, ip, iHighLimit, extDict, rep, ll0, matches, lengthToBeat, 3);
|
|
default :
|
|
case 4 : return ZSTD_insertBtAndGetAllMatches(ms, cParams, ip, iHighLimit, extDict, rep, ll0, matches, lengthToBeat, 4);
|
|
case 5 : return ZSTD_insertBtAndGetAllMatches(ms, cParams, ip, iHighLimit, extDict, rep, ll0, matches, lengthToBeat, 5);
|
|
case 7 :
|
|
case 6 : return ZSTD_insertBtAndGetAllMatches(ms, cParams, ip, iHighLimit, extDict, rep, ll0, matches, lengthToBeat, 6);
|
|
}
|
|
}
|
|
|
|
|
|
/*-*******************************
|
|
* Optimal parser
|
|
*********************************/
|
|
typedef struct repcodes_s {
|
|
U32 rep[3];
|
|
} repcodes_t;
|
|
|
|
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;
|
|
}
|
|
|
|
|
|
typedef struct {
|
|
const BYTE* anchor;
|
|
U32 litlen;
|
|
U32 rawLitCost;
|
|
} cachedLiteralPrice_t;
|
|
|
|
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;
|
|
}
|
|
|
|
{ U32 const rawLitCost = startCost + ZSTD_rawLiteralsCost(startPosition, remainingLength, optStatePtr);
|
|
cachedLitPrice->anchor = anchor;
|
|
cachedLitPrice->litlen = litlen;
|
|
cachedLitPrice->rawLitCost = rawLitCost;
|
|
return rawLitCost;
|
|
}
|
|
}
|
|
|
|
static U32 ZSTD_fullLiteralsCost_cached(
|
|
cachedLiteralPrice_t* const cachedLitPrice,
|
|
const BYTE* const anchor, U32 const litlen,
|
|
const optState_t* const optStatePtr)
|
|
{
|
|
return ZSTD_rawLiteralsCost_cached(cachedLitPrice, anchor, litlen, optStatePtr)
|
|
+ ZSTD_litLengthPrice(litlen, optStatePtr);
|
|
}
|
|
|
|
static int ZSTD_literalsContribution_cached(
|
|
cachedLiteralPrice_t* const cachedLitPrice,
|
|
const BYTE* const anchor, U32 const litlen,
|
|
const optState_t* const optStatePtr)
|
|
{
|
|
int const contribution = ZSTD_rawLiteralsCost_cached(cachedLitPrice, anchor, litlen, optStatePtr)
|
|
+ ZSTD_litLengthContribution(litlen, optStatePtr);
|
|
return contribution;
|
|
}
|
|
|
|
FORCE_INLINE_TEMPLATE size_t
|
|
ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
|
|
seqStore_t* seqStore,
|
|
U32 rep[ZSTD_REP_NUM],
|
|
const ZSTD_compressionParameters* cParams,
|
|
const void* src, size_t srcSize,
|
|
const int optLevel, const int extDict)
|
|
{
|
|
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;
|
|
|
|
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;
|
|
cachedLiteralPrice_t cachedLitPrice;
|
|
|
|
/* init */
|
|
DEBUGLOG(5, "ZSTD_compressBlock_opt_generic");
|
|
ms->nextToUpdate3 = ms->nextToUpdate;
|
|
ZSTD_rescaleFreqs(optStatePtr, (const BYTE*)src, srcSize);
|
|
ip += (ip==prefixStart);
|
|
memset(&cachedLitPrice, 0, sizeof(cachedLitPrice));
|
|
|
|
/* Match Loop */
|
|
while (ip < ilimit) {
|
|
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(ms, cParams, ip, iend, extDict, 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; /* means is_a_literal */
|
|
opt[0].litlen = litlen;
|
|
|
|
/* large match -> immediate encoding */
|
|
{ U32 const maxML = matches[nbMatches-1].len;
|
|
U32 const maxOffset = matches[nbMatches-1].off;
|
|
DEBUGLOG(7, "found %u matches of maxLength=%u and maxOffset=%u at cPos=%u => start new serie",
|
|
nbMatches, maxML, maxOffset, (U32)(ip-prefixStart));
|
|
|
|
if (maxML > sufficient_len) {
|
|
best_mlen = maxML;
|
|
best_off = maxOffset;
|
|
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 = 1; pos < minMatch; pos++) {
|
|
opt[pos].price = ZSTD_MAX_PRICE; /* mlen, litlen and price will be fixed during forward scanning */
|
|
}
|
|
for (matchNb = 0; matchNb < nbMatches; matchNb++) {
|
|
U32 const offset = matches[matchNb].off;
|
|
U32 const end = matches[matchNb].len;
|
|
repcodes_t const repHistory = ZSTD_updateRep(rep, offset, ll0);
|
|
for ( ; pos <= end ; pos++ ) {
|
|
U32 const matchPrice = ZSTD_getMatchPrice(offset, pos, optStatePtr, optLevel);
|
|
U32 const sequencePrice = literalsPrice + matchPrice;
|
|
DEBUGLOG(7, "rPos:%u => set initial price : %.2f",
|
|
pos, ZSTD_fCost(sequencePrice));
|
|
opt[pos].mlen = pos;
|
|
opt[pos].off = offset;
|
|
opt[pos].litlen = litlen;
|
|
opt[pos].price = sequencePrice;
|
|
ZSTD_STATIC_ASSERT(sizeof(opt[pos].rep) == sizeof(repHistory));
|
|
memcpy(opt[pos].rep, &repHistory, sizeof(repHistory));
|
|
} }
|
|
last_pos = pos-1;
|
|
}
|
|
}
|
|
|
|
/* check further positions */
|
|
for (cur = 1; cur <= last_pos; cur++) {
|
|
const BYTE* const inr = ip + cur;
|
|
assert(cur < ZSTD_OPT_NUM);
|
|
|
|
/* 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_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 (%.2f<=%.2f) using literal",
|
|
cur, ZSTD_fCost(price), ZSTD_fCost(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));
|
|
} else {
|
|
DEBUGLOG(7, "rPos:%u : literal would cost more (%.2f>%.2f)",
|
|
cur, ZSTD_fCost(price), ZSTD_fCost(opt[cur].price));
|
|
}
|
|
}
|
|
|
|
/* last match must start at a minimum distance of 8 from oend */
|
|
if (inr > ilimit) continue;
|
|
|
|
if (cur == last_pos) break;
|
|
|
|
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);
|
|
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(ms, cParams, inr, iend, extDict, opt[cur].rep, ll0, matches, minMatch);
|
|
U32 matchNb;
|
|
if (!nbMatches) {
|
|
DEBUGLOG(7, "rPos:%u : no match found", cur);
|
|
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;
|
|
} }
|
|
|
|
/* 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--) { /* scan downward */
|
|
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 (%.2f<%.2f)",
|
|
pos, 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 */
|
|
opt[pos].mlen = mlen;
|
|
opt[pos].off = offset;
|
|
opt[pos].litlen = litlen;
|
|
opt[pos].price = price;
|
|
ZSTD_STATIC_ASSERT(sizeof(opt[pos].rep) == sizeof(repHistory));
|
|
memcpy(opt[pos].rep, &repHistory, sizeof(repHistory));
|
|
} else {
|
|
if (optLevel==0) break; /* early update abort; gets ~+10% speed for about -0.01 ratio loss */
|
|
}
|
|
} } }
|
|
} /* for (cur = 1; cur <= last_pos; cur++) */
|
|
|
|
best_mlen = opt[last_pos].mlen;
|
|
best_off = opt[last_pos].off;
|
|
cur = last_pos - best_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;
|
|
} }
|
|
|
|
/* 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] = 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;
|
|
} }
|
|
|
|
ZSTD_updateStats(optStatePtr, llen, anchor, offset, mlen);
|
|
ZSTD_storeSeq(seqStore, llen, anchor, offset, mlen-MINMATCH);
|
|
anchor = ip;
|
|
} }
|
|
ZSTD_setLog2Prices(optStatePtr);
|
|
} /* 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],
|
|
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
|
|
{
|
|
DEBUGLOG(5, "ZSTD_compressBlock_btopt");
|
|
return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, cParams, src, srcSize, 0 /*optLevel*/, 0 /*extDict*/);
|
|
}
|
|
|
|
size_t ZSTD_compressBlock_btultra(
|
|
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
|
|
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
|
|
{
|
|
return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, cParams, src, srcSize, 2 /*optLevel*/, 0 /*extDict*/);
|
|
}
|
|
|
|
size_t ZSTD_compressBlock_btopt_extDict(
|
|
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
|
|
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
|
|
{
|
|
return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, cParams, src, srcSize, 0 /*optLevel*/, 1 /*extDict*/);
|
|
}
|
|
|
|
size_t ZSTD_compressBlock_btultra_extDict(
|
|
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
|
|
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
|
|
{
|
|
return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, cParams, src, srcSize, 2 /*optLevel*/, 1 /*extDict*/);
|
|
}
|