1*a28cd43dSSascha Wildner /*
2*a28cd43dSSascha Wildner * Copyright (c) 2016-2020, Przemyslaw Skibinski, Yann Collet, Facebook, Inc.
3*a28cd43dSSascha Wildner * All rights reserved.
4*a28cd43dSSascha Wildner *
5*a28cd43dSSascha Wildner * This source code is licensed under both the BSD-style license (found in the
6*a28cd43dSSascha Wildner * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7*a28cd43dSSascha Wildner * in the COPYING file in the root directory of this source tree).
8*a28cd43dSSascha Wildner * You may select, at your option, one of the above-listed licenses.
9*a28cd43dSSascha Wildner */
10*a28cd43dSSascha Wildner
11*a28cd43dSSascha Wildner #include "zstd_compress_internal.h"
12*a28cd43dSSascha Wildner #include "hist.h"
13*a28cd43dSSascha Wildner #include "zstd_opt.h"
14*a28cd43dSSascha Wildner
15*a28cd43dSSascha Wildner
16*a28cd43dSSascha Wildner #define ZSTD_LITFREQ_ADD 2 /* scaling factor for litFreq, so that frequencies adapt faster to new stats */
17*a28cd43dSSascha Wildner #define ZSTD_FREQ_DIV 4 /* log factor when using previous stats to init next stats */
18*a28cd43dSSascha Wildner #define ZSTD_MAX_PRICE (1<<30)
19*a28cd43dSSascha Wildner
20*a28cd43dSSascha Wildner #define ZSTD_PREDEF_THRESHOLD 1024 /* if srcSize < ZSTD_PREDEF_THRESHOLD, symbols' cost is assumed static, directly determined by pre-defined distributions */
21*a28cd43dSSascha Wildner
22*a28cd43dSSascha Wildner
23*a28cd43dSSascha Wildner /*-*************************************
24*a28cd43dSSascha Wildner * Price functions for optimal parser
25*a28cd43dSSascha Wildner ***************************************/
26*a28cd43dSSascha Wildner
27*a28cd43dSSascha Wildner #if 0 /* approximation at bit level */
28*a28cd43dSSascha Wildner # define BITCOST_ACCURACY 0
29*a28cd43dSSascha Wildner # define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY)
30*a28cd43dSSascha Wildner # define WEIGHT(stat) ((void)opt, ZSTD_bitWeight(stat))
31*a28cd43dSSascha Wildner #elif 0 /* fractional bit accuracy */
32*a28cd43dSSascha Wildner # define BITCOST_ACCURACY 8
33*a28cd43dSSascha Wildner # define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY)
34*a28cd43dSSascha Wildner # define WEIGHT(stat,opt) ((void)opt, ZSTD_fracWeight(stat))
35*a28cd43dSSascha Wildner #else /* opt==approx, ultra==accurate */
36*a28cd43dSSascha Wildner # define BITCOST_ACCURACY 8
37*a28cd43dSSascha Wildner # define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY)
38*a28cd43dSSascha Wildner # define WEIGHT(stat,opt) (opt ? ZSTD_fracWeight(stat) : ZSTD_bitWeight(stat))
39*a28cd43dSSascha Wildner #endif
40*a28cd43dSSascha Wildner
ZSTD_bitWeight(U32 stat)41*a28cd43dSSascha Wildner MEM_STATIC U32 ZSTD_bitWeight(U32 stat)
42*a28cd43dSSascha Wildner {
43*a28cd43dSSascha Wildner return (ZSTD_highbit32(stat+1) * BITCOST_MULTIPLIER);
44*a28cd43dSSascha Wildner }
45*a28cd43dSSascha Wildner
ZSTD_fracWeight(U32 rawStat)46*a28cd43dSSascha Wildner MEM_STATIC U32 ZSTD_fracWeight(U32 rawStat)
47*a28cd43dSSascha Wildner {
48*a28cd43dSSascha Wildner U32 const stat = rawStat + 1;
49*a28cd43dSSascha Wildner U32 const hb = ZSTD_highbit32(stat);
50*a28cd43dSSascha Wildner U32 const BWeight = hb * BITCOST_MULTIPLIER;
51*a28cd43dSSascha Wildner U32 const FWeight = (stat << BITCOST_ACCURACY) >> hb;
52*a28cd43dSSascha Wildner U32 const weight = BWeight + FWeight;
53*a28cd43dSSascha Wildner assert(hb + BITCOST_ACCURACY < 31);
54*a28cd43dSSascha Wildner return weight;
55*a28cd43dSSascha Wildner }
56*a28cd43dSSascha Wildner
57*a28cd43dSSascha Wildner #if (DEBUGLEVEL>=2)
58*a28cd43dSSascha Wildner /* debugging function,
59*a28cd43dSSascha Wildner * @return price in bytes as fractional value
60*a28cd43dSSascha Wildner * for debug messages only */
ZSTD_fCost(U32 price)61*a28cd43dSSascha Wildner MEM_STATIC double ZSTD_fCost(U32 price)
62*a28cd43dSSascha Wildner {
63*a28cd43dSSascha Wildner return (double)price / (BITCOST_MULTIPLIER*8);
64*a28cd43dSSascha Wildner }
65*a28cd43dSSascha Wildner #endif
66*a28cd43dSSascha Wildner
ZSTD_compressedLiterals(optState_t const * const optPtr)67*a28cd43dSSascha Wildner static int ZSTD_compressedLiterals(optState_t const* const optPtr)
68*a28cd43dSSascha Wildner {
69*a28cd43dSSascha Wildner return optPtr->literalCompressionMode != ZSTD_lcm_uncompressed;
70*a28cd43dSSascha Wildner }
71*a28cd43dSSascha Wildner
ZSTD_setBasePrices(optState_t * optPtr,int optLevel)72*a28cd43dSSascha Wildner static void ZSTD_setBasePrices(optState_t* optPtr, int optLevel)
73*a28cd43dSSascha Wildner {
74*a28cd43dSSascha Wildner if (ZSTD_compressedLiterals(optPtr))
75*a28cd43dSSascha Wildner optPtr->litSumBasePrice = WEIGHT(optPtr->litSum, optLevel);
76*a28cd43dSSascha Wildner optPtr->litLengthSumBasePrice = WEIGHT(optPtr->litLengthSum, optLevel);
77*a28cd43dSSascha Wildner optPtr->matchLengthSumBasePrice = WEIGHT(optPtr->matchLengthSum, optLevel);
78*a28cd43dSSascha Wildner optPtr->offCodeSumBasePrice = WEIGHT(optPtr->offCodeSum, optLevel);
79*a28cd43dSSascha Wildner }
80*a28cd43dSSascha Wildner
81*a28cd43dSSascha Wildner
82*a28cd43dSSascha Wildner /* ZSTD_downscaleStat() :
83*a28cd43dSSascha Wildner * reduce all elements in table by a factor 2^(ZSTD_FREQ_DIV+malus)
84*a28cd43dSSascha Wildner * return the resulting sum of elements */
ZSTD_downscaleStat(unsigned * table,U32 lastEltIndex,int malus)85*a28cd43dSSascha Wildner static U32 ZSTD_downscaleStat(unsigned* table, U32 lastEltIndex, int malus)
86*a28cd43dSSascha Wildner {
87*a28cd43dSSascha Wildner U32 s, sum=0;
88*a28cd43dSSascha Wildner DEBUGLOG(5, "ZSTD_downscaleStat (nbElts=%u)", (unsigned)lastEltIndex+1);
89*a28cd43dSSascha Wildner assert(ZSTD_FREQ_DIV+malus > 0 && ZSTD_FREQ_DIV+malus < 31);
90*a28cd43dSSascha Wildner for (s=0; s<lastEltIndex+1; s++) {
91*a28cd43dSSascha Wildner table[s] = 1 + (table[s] >> (ZSTD_FREQ_DIV+malus));
92*a28cd43dSSascha Wildner sum += table[s];
93*a28cd43dSSascha Wildner }
94*a28cd43dSSascha Wildner return sum;
95*a28cd43dSSascha Wildner }
96*a28cd43dSSascha Wildner
97*a28cd43dSSascha Wildner /* ZSTD_rescaleFreqs() :
98*a28cd43dSSascha Wildner * if first block (detected by optPtr->litLengthSum == 0) : init statistics
99*a28cd43dSSascha Wildner * take hints from dictionary if there is one
100*a28cd43dSSascha Wildner * or init from zero, using src for literals stats, or flat 1 for match symbols
101*a28cd43dSSascha Wildner * otherwise downscale existing stats, to be used as seed for next block.
102*a28cd43dSSascha Wildner */
103*a28cd43dSSascha Wildner static void
ZSTD_rescaleFreqs(optState_t * const optPtr,const BYTE * const src,size_t const srcSize,int const optLevel)104*a28cd43dSSascha Wildner ZSTD_rescaleFreqs(optState_t* const optPtr,
105*a28cd43dSSascha Wildner const BYTE* const src, size_t const srcSize,
106*a28cd43dSSascha Wildner int const optLevel)
107*a28cd43dSSascha Wildner {
108*a28cd43dSSascha Wildner int const compressedLiterals = ZSTD_compressedLiterals(optPtr);
109*a28cd43dSSascha Wildner DEBUGLOG(5, "ZSTD_rescaleFreqs (srcSize=%u)", (unsigned)srcSize);
110*a28cd43dSSascha Wildner optPtr->priceType = zop_dynamic;
111*a28cd43dSSascha Wildner
112*a28cd43dSSascha Wildner if (optPtr->litLengthSum == 0) { /* first block : init */
113*a28cd43dSSascha Wildner if (srcSize <= ZSTD_PREDEF_THRESHOLD) { /* heuristic */
114*a28cd43dSSascha Wildner DEBUGLOG(5, "(srcSize <= ZSTD_PREDEF_THRESHOLD) => zop_predef");
115*a28cd43dSSascha Wildner optPtr->priceType = zop_predef;
116*a28cd43dSSascha Wildner }
117*a28cd43dSSascha Wildner
118*a28cd43dSSascha Wildner assert(optPtr->symbolCosts != NULL);
119*a28cd43dSSascha Wildner if (optPtr->symbolCosts->huf.repeatMode == HUF_repeat_valid) {
120*a28cd43dSSascha Wildner /* huffman table presumed generated by dictionary */
121*a28cd43dSSascha Wildner optPtr->priceType = zop_dynamic;
122*a28cd43dSSascha Wildner
123*a28cd43dSSascha Wildner if (compressedLiterals) {
124*a28cd43dSSascha Wildner unsigned lit;
125*a28cd43dSSascha Wildner assert(optPtr->litFreq != NULL);
126*a28cd43dSSascha Wildner optPtr->litSum = 0;
127*a28cd43dSSascha Wildner for (lit=0; lit<=MaxLit; lit++) {
128*a28cd43dSSascha Wildner U32 const scaleLog = 11; /* scale to 2K */
129*a28cd43dSSascha Wildner U32 const bitCost = HUF_getNbBits(optPtr->symbolCosts->huf.CTable, lit);
130*a28cd43dSSascha Wildner assert(bitCost <= scaleLog);
131*a28cd43dSSascha Wildner optPtr->litFreq[lit] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
132*a28cd43dSSascha Wildner optPtr->litSum += optPtr->litFreq[lit];
133*a28cd43dSSascha Wildner } }
134*a28cd43dSSascha Wildner
135*a28cd43dSSascha Wildner { unsigned ll;
136*a28cd43dSSascha Wildner FSE_CState_t llstate;
137*a28cd43dSSascha Wildner FSE_initCState(&llstate, optPtr->symbolCosts->fse.litlengthCTable);
138*a28cd43dSSascha Wildner optPtr->litLengthSum = 0;
139*a28cd43dSSascha Wildner for (ll=0; ll<=MaxLL; ll++) {
140*a28cd43dSSascha Wildner U32 const scaleLog = 10; /* scale to 1K */
141*a28cd43dSSascha Wildner U32 const bitCost = FSE_getMaxNbBits(llstate.symbolTT, ll);
142*a28cd43dSSascha Wildner assert(bitCost < scaleLog);
143*a28cd43dSSascha Wildner optPtr->litLengthFreq[ll] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
144*a28cd43dSSascha Wildner optPtr->litLengthSum += optPtr->litLengthFreq[ll];
145*a28cd43dSSascha Wildner } }
146*a28cd43dSSascha Wildner
147*a28cd43dSSascha Wildner { unsigned ml;
148*a28cd43dSSascha Wildner FSE_CState_t mlstate;
149*a28cd43dSSascha Wildner FSE_initCState(&mlstate, optPtr->symbolCosts->fse.matchlengthCTable);
150*a28cd43dSSascha Wildner optPtr->matchLengthSum = 0;
151*a28cd43dSSascha Wildner for (ml=0; ml<=MaxML; ml++) {
152*a28cd43dSSascha Wildner U32 const scaleLog = 10;
153*a28cd43dSSascha Wildner U32 const bitCost = FSE_getMaxNbBits(mlstate.symbolTT, ml);
154*a28cd43dSSascha Wildner assert(bitCost < scaleLog);
155*a28cd43dSSascha Wildner optPtr->matchLengthFreq[ml] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
156*a28cd43dSSascha Wildner optPtr->matchLengthSum += optPtr->matchLengthFreq[ml];
157*a28cd43dSSascha Wildner } }
158*a28cd43dSSascha Wildner
159*a28cd43dSSascha Wildner { unsigned of;
160*a28cd43dSSascha Wildner FSE_CState_t ofstate;
161*a28cd43dSSascha Wildner FSE_initCState(&ofstate, optPtr->symbolCosts->fse.offcodeCTable);
162*a28cd43dSSascha Wildner optPtr->offCodeSum = 0;
163*a28cd43dSSascha Wildner for (of=0; of<=MaxOff; of++) {
164*a28cd43dSSascha Wildner U32 const scaleLog = 10;
165*a28cd43dSSascha Wildner U32 const bitCost = FSE_getMaxNbBits(ofstate.symbolTT, of);
166*a28cd43dSSascha Wildner assert(bitCost < scaleLog);
167*a28cd43dSSascha Wildner optPtr->offCodeFreq[of] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
168*a28cd43dSSascha Wildner optPtr->offCodeSum += optPtr->offCodeFreq[of];
169*a28cd43dSSascha Wildner } }
170*a28cd43dSSascha Wildner
171*a28cd43dSSascha Wildner } else { /* not a dictionary */
172*a28cd43dSSascha Wildner
173*a28cd43dSSascha Wildner assert(optPtr->litFreq != NULL);
174*a28cd43dSSascha Wildner if (compressedLiterals) {
175*a28cd43dSSascha Wildner unsigned lit = MaxLit;
176*a28cd43dSSascha Wildner HIST_count_simple(optPtr->litFreq, &lit, src, srcSize); /* use raw first block to init statistics */
177*a28cd43dSSascha Wildner optPtr->litSum = ZSTD_downscaleStat(optPtr->litFreq, MaxLit, 1);
178*a28cd43dSSascha Wildner }
179*a28cd43dSSascha Wildner
180*a28cd43dSSascha Wildner { unsigned ll;
181*a28cd43dSSascha Wildner for (ll=0; ll<=MaxLL; ll++)
182*a28cd43dSSascha Wildner optPtr->litLengthFreq[ll] = 1;
183*a28cd43dSSascha Wildner }
184*a28cd43dSSascha Wildner optPtr->litLengthSum = MaxLL+1;
185*a28cd43dSSascha Wildner
186*a28cd43dSSascha Wildner { unsigned ml;
187*a28cd43dSSascha Wildner for (ml=0; ml<=MaxML; ml++)
188*a28cd43dSSascha Wildner optPtr->matchLengthFreq[ml] = 1;
189*a28cd43dSSascha Wildner }
190*a28cd43dSSascha Wildner optPtr->matchLengthSum = MaxML+1;
191*a28cd43dSSascha Wildner
192*a28cd43dSSascha Wildner { unsigned of;
193*a28cd43dSSascha Wildner for (of=0; of<=MaxOff; of++)
194*a28cd43dSSascha Wildner optPtr->offCodeFreq[of] = 1;
195*a28cd43dSSascha Wildner }
196*a28cd43dSSascha Wildner optPtr->offCodeSum = MaxOff+1;
197*a28cd43dSSascha Wildner
198*a28cd43dSSascha Wildner }
199*a28cd43dSSascha Wildner
200*a28cd43dSSascha Wildner } else { /* new block : re-use previous statistics, scaled down */
201*a28cd43dSSascha Wildner
202*a28cd43dSSascha Wildner if (compressedLiterals)
203*a28cd43dSSascha Wildner optPtr->litSum = ZSTD_downscaleStat(optPtr->litFreq, MaxLit, 1);
204*a28cd43dSSascha Wildner optPtr->litLengthSum = ZSTD_downscaleStat(optPtr->litLengthFreq, MaxLL, 0);
205*a28cd43dSSascha Wildner optPtr->matchLengthSum = ZSTD_downscaleStat(optPtr->matchLengthFreq, MaxML, 0);
206*a28cd43dSSascha Wildner optPtr->offCodeSum = ZSTD_downscaleStat(optPtr->offCodeFreq, MaxOff, 0);
207*a28cd43dSSascha Wildner }
208*a28cd43dSSascha Wildner
209*a28cd43dSSascha Wildner ZSTD_setBasePrices(optPtr, optLevel);
210*a28cd43dSSascha Wildner }
211*a28cd43dSSascha Wildner
212*a28cd43dSSascha Wildner /* ZSTD_rawLiteralsCost() :
213*a28cd43dSSascha Wildner * price of literals (only) in specified segment (which length can be 0).
214*a28cd43dSSascha Wildner * does not include price of literalLength symbol */
ZSTD_rawLiteralsCost(const BYTE * const literals,U32 const litLength,const optState_t * const optPtr,int optLevel)215*a28cd43dSSascha Wildner static U32 ZSTD_rawLiteralsCost(const BYTE* const literals, U32 const litLength,
216*a28cd43dSSascha Wildner const optState_t* const optPtr,
217*a28cd43dSSascha Wildner int optLevel)
218*a28cd43dSSascha Wildner {
219*a28cd43dSSascha Wildner if (litLength == 0) return 0;
220*a28cd43dSSascha Wildner
221*a28cd43dSSascha Wildner if (!ZSTD_compressedLiterals(optPtr))
222*a28cd43dSSascha Wildner return (litLength << 3) * BITCOST_MULTIPLIER; /* Uncompressed - 8 bytes per literal. */
223*a28cd43dSSascha Wildner
224*a28cd43dSSascha Wildner if (optPtr->priceType == zop_predef)
225*a28cd43dSSascha Wildner return (litLength*6) * BITCOST_MULTIPLIER; /* 6 bit per literal - no statistic used */
226*a28cd43dSSascha Wildner
227*a28cd43dSSascha Wildner /* dynamic statistics */
228*a28cd43dSSascha Wildner { U32 price = litLength * optPtr->litSumBasePrice;
229*a28cd43dSSascha Wildner U32 u;
230*a28cd43dSSascha Wildner for (u=0; u < litLength; u++) {
231*a28cd43dSSascha Wildner assert(WEIGHT(optPtr->litFreq[literals[u]], optLevel) <= optPtr->litSumBasePrice); /* literal cost should never be negative */
232*a28cd43dSSascha Wildner price -= WEIGHT(optPtr->litFreq[literals[u]], optLevel);
233*a28cd43dSSascha Wildner }
234*a28cd43dSSascha Wildner return price;
235*a28cd43dSSascha Wildner }
236*a28cd43dSSascha Wildner }
237*a28cd43dSSascha Wildner
238*a28cd43dSSascha Wildner /* ZSTD_litLengthPrice() :
239*a28cd43dSSascha Wildner * cost of literalLength symbol */
ZSTD_litLengthPrice(U32 const litLength,const optState_t * const optPtr,int optLevel)240*a28cd43dSSascha Wildner static U32 ZSTD_litLengthPrice(U32 const litLength, const optState_t* const optPtr, int optLevel)
241*a28cd43dSSascha Wildner {
242*a28cd43dSSascha Wildner if (optPtr->priceType == zop_predef) return WEIGHT(litLength, optLevel);
243*a28cd43dSSascha Wildner
244*a28cd43dSSascha Wildner /* dynamic statistics */
245*a28cd43dSSascha Wildner { U32 const llCode = ZSTD_LLcode(litLength);
246*a28cd43dSSascha Wildner return (LL_bits[llCode] * BITCOST_MULTIPLIER)
247*a28cd43dSSascha Wildner + optPtr->litLengthSumBasePrice
248*a28cd43dSSascha Wildner - WEIGHT(optPtr->litLengthFreq[llCode], optLevel);
249*a28cd43dSSascha Wildner }
250*a28cd43dSSascha Wildner }
251*a28cd43dSSascha Wildner
252*a28cd43dSSascha Wildner /* ZSTD_getMatchPrice() :
253*a28cd43dSSascha Wildner * Provides the cost of the match part (offset + matchLength) of a sequence
254*a28cd43dSSascha Wildner * Must be combined with ZSTD_fullLiteralsCost() to get the full cost of a sequence.
255*a28cd43dSSascha Wildner * optLevel: when <2, favors small offset for decompression speed (improved cache efficiency) */
256*a28cd43dSSascha Wildner FORCE_INLINE_TEMPLATE U32
ZSTD_getMatchPrice(U32 const offset,U32 const matchLength,const optState_t * const optPtr,int const optLevel)257*a28cd43dSSascha Wildner ZSTD_getMatchPrice(U32 const offset,
258*a28cd43dSSascha Wildner U32 const matchLength,
259*a28cd43dSSascha Wildner const optState_t* const optPtr,
260*a28cd43dSSascha Wildner int const optLevel)
261*a28cd43dSSascha Wildner {
262*a28cd43dSSascha Wildner U32 price;
263*a28cd43dSSascha Wildner U32 const offCode = ZSTD_highbit32(offset+1);
264*a28cd43dSSascha Wildner U32 const mlBase = matchLength - MINMATCH;
265*a28cd43dSSascha Wildner assert(matchLength >= MINMATCH);
266*a28cd43dSSascha Wildner
267*a28cd43dSSascha Wildner if (optPtr->priceType == zop_predef) /* fixed scheme, do not use statistics */
268*a28cd43dSSascha Wildner return WEIGHT(mlBase, optLevel) + ((16 + offCode) * BITCOST_MULTIPLIER);
269*a28cd43dSSascha Wildner
270*a28cd43dSSascha Wildner /* dynamic statistics */
271*a28cd43dSSascha Wildner price = (offCode * BITCOST_MULTIPLIER) + (optPtr->offCodeSumBasePrice - WEIGHT(optPtr->offCodeFreq[offCode], optLevel));
272*a28cd43dSSascha Wildner if ((optLevel<2) /*static*/ && offCode >= 20)
273*a28cd43dSSascha Wildner price += (offCode-19)*2 * BITCOST_MULTIPLIER; /* handicap for long distance offsets, favor decompression speed */
274*a28cd43dSSascha Wildner
275*a28cd43dSSascha Wildner /* match Length */
276*a28cd43dSSascha Wildner { U32 const mlCode = ZSTD_MLcode(mlBase);
277*a28cd43dSSascha Wildner price += (ML_bits[mlCode] * BITCOST_MULTIPLIER) + (optPtr->matchLengthSumBasePrice - WEIGHT(optPtr->matchLengthFreq[mlCode], optLevel));
278*a28cd43dSSascha Wildner }
279*a28cd43dSSascha Wildner
280*a28cd43dSSascha Wildner price += BITCOST_MULTIPLIER / 5; /* heuristic : make matches a bit more costly to favor less sequences -> faster decompression speed */
281*a28cd43dSSascha Wildner
282*a28cd43dSSascha Wildner DEBUGLOG(8, "ZSTD_getMatchPrice(ml:%u) = %u", matchLength, price);
283*a28cd43dSSascha Wildner return price;
284*a28cd43dSSascha Wildner }
285*a28cd43dSSascha Wildner
286*a28cd43dSSascha Wildner /* ZSTD_updateStats() :
287*a28cd43dSSascha Wildner * assumption : literals + litLengtn <= iend */
ZSTD_updateStats(optState_t * const optPtr,U32 litLength,const BYTE * literals,U32 offsetCode,U32 matchLength)288*a28cd43dSSascha Wildner static void ZSTD_updateStats(optState_t* const optPtr,
289*a28cd43dSSascha Wildner U32 litLength, const BYTE* literals,
290*a28cd43dSSascha Wildner U32 offsetCode, U32 matchLength)
291*a28cd43dSSascha Wildner {
292*a28cd43dSSascha Wildner /* literals */
293*a28cd43dSSascha Wildner if (ZSTD_compressedLiterals(optPtr)) {
294*a28cd43dSSascha Wildner U32 u;
295*a28cd43dSSascha Wildner for (u=0; u < litLength; u++)
296*a28cd43dSSascha Wildner optPtr->litFreq[literals[u]] += ZSTD_LITFREQ_ADD;
297*a28cd43dSSascha Wildner optPtr->litSum += litLength*ZSTD_LITFREQ_ADD;
298*a28cd43dSSascha Wildner }
299*a28cd43dSSascha Wildner
300*a28cd43dSSascha Wildner /* literal Length */
301*a28cd43dSSascha Wildner { U32 const llCode = ZSTD_LLcode(litLength);
302*a28cd43dSSascha Wildner optPtr->litLengthFreq[llCode]++;
303*a28cd43dSSascha Wildner optPtr->litLengthSum++;
304*a28cd43dSSascha Wildner }
305*a28cd43dSSascha Wildner
306*a28cd43dSSascha Wildner /* match offset code (0-2=>repCode; 3+=>offset+2) */
307*a28cd43dSSascha Wildner { U32 const offCode = ZSTD_highbit32(offsetCode+1);
308*a28cd43dSSascha Wildner assert(offCode <= MaxOff);
309*a28cd43dSSascha Wildner optPtr->offCodeFreq[offCode]++;
310*a28cd43dSSascha Wildner optPtr->offCodeSum++;
311*a28cd43dSSascha Wildner }
312*a28cd43dSSascha Wildner
313*a28cd43dSSascha Wildner /* match Length */
314*a28cd43dSSascha Wildner { U32 const mlBase = matchLength - MINMATCH;
315*a28cd43dSSascha Wildner U32 const mlCode = ZSTD_MLcode(mlBase);
316*a28cd43dSSascha Wildner optPtr->matchLengthFreq[mlCode]++;
317*a28cd43dSSascha Wildner optPtr->matchLengthSum++;
318*a28cd43dSSascha Wildner }
319*a28cd43dSSascha Wildner }
320*a28cd43dSSascha Wildner
321*a28cd43dSSascha Wildner
322*a28cd43dSSascha Wildner /* ZSTD_readMINMATCH() :
323*a28cd43dSSascha Wildner * function safe only for comparisons
324*a28cd43dSSascha Wildner * assumption : memPtr must be at least 4 bytes before end of buffer */
ZSTD_readMINMATCH(const void * memPtr,U32 length)325*a28cd43dSSascha Wildner MEM_STATIC U32 ZSTD_readMINMATCH(const void* memPtr, U32 length)
326*a28cd43dSSascha Wildner {
327*a28cd43dSSascha Wildner switch (length)
328*a28cd43dSSascha Wildner {
329*a28cd43dSSascha Wildner default :
330*a28cd43dSSascha Wildner case 4 : return MEM_read32(memPtr);
331*a28cd43dSSascha Wildner case 3 : if (MEM_isLittleEndian())
332*a28cd43dSSascha Wildner return MEM_read32(memPtr)<<8;
333*a28cd43dSSascha Wildner else
334*a28cd43dSSascha Wildner return MEM_read32(memPtr)>>8;
335*a28cd43dSSascha Wildner }
336*a28cd43dSSascha Wildner }
337*a28cd43dSSascha Wildner
338*a28cd43dSSascha Wildner
339*a28cd43dSSascha Wildner /* Update hashTable3 up to ip (excluded)
340*a28cd43dSSascha Wildner Assumption : always within prefix (i.e. not within extDict) */
ZSTD_insertAndFindFirstIndexHash3(ZSTD_matchState_t * ms,U32 * nextToUpdate3,const BYTE * const ip)341*a28cd43dSSascha Wildner static U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_matchState_t* ms,
342*a28cd43dSSascha Wildner U32* nextToUpdate3,
343*a28cd43dSSascha Wildner const BYTE* const ip)
344*a28cd43dSSascha Wildner {
345*a28cd43dSSascha Wildner U32* const hashTable3 = ms->hashTable3;
346*a28cd43dSSascha Wildner U32 const hashLog3 = ms->hashLog3;
347*a28cd43dSSascha Wildner const BYTE* const base = ms->window.base;
348*a28cd43dSSascha Wildner U32 idx = *nextToUpdate3;
349*a28cd43dSSascha Wildner U32 const target = (U32)(ip - base);
350*a28cd43dSSascha Wildner size_t const hash3 = ZSTD_hash3Ptr(ip, hashLog3);
351*a28cd43dSSascha Wildner assert(hashLog3 > 0);
352*a28cd43dSSascha Wildner
353*a28cd43dSSascha Wildner while(idx < target) {
354*a28cd43dSSascha Wildner hashTable3[ZSTD_hash3Ptr(base+idx, hashLog3)] = idx;
355*a28cd43dSSascha Wildner idx++;
356*a28cd43dSSascha Wildner }
357*a28cd43dSSascha Wildner
358*a28cd43dSSascha Wildner *nextToUpdate3 = target;
359*a28cd43dSSascha Wildner return hashTable3[hash3];
360*a28cd43dSSascha Wildner }
361*a28cd43dSSascha Wildner
362*a28cd43dSSascha Wildner
363*a28cd43dSSascha Wildner /*-*************************************
364*a28cd43dSSascha Wildner * Binary Tree search
365*a28cd43dSSascha Wildner ***************************************/
366*a28cd43dSSascha Wildner /** ZSTD_insertBt1() : add one or multiple positions to tree.
367*a28cd43dSSascha Wildner * ip : assumed <= iend-8 .
368*a28cd43dSSascha Wildner * @return : nb of positions added */
ZSTD_insertBt1(ZSTD_matchState_t * ms,const BYTE * const ip,const BYTE * const iend,U32 const mls,const int extDict)369*a28cd43dSSascha Wildner static U32 ZSTD_insertBt1(
370*a28cd43dSSascha Wildner ZSTD_matchState_t* ms,
371*a28cd43dSSascha Wildner const BYTE* const ip, const BYTE* const iend,
372*a28cd43dSSascha Wildner U32 const mls, const int extDict)
373*a28cd43dSSascha Wildner {
374*a28cd43dSSascha Wildner const ZSTD_compressionParameters* const cParams = &ms->cParams;
375*a28cd43dSSascha Wildner U32* const hashTable = ms->hashTable;
376*a28cd43dSSascha Wildner U32 const hashLog = cParams->hashLog;
377*a28cd43dSSascha Wildner size_t const h = ZSTD_hashPtr(ip, hashLog, mls);
378*a28cd43dSSascha Wildner U32* const bt = ms->chainTable;
379*a28cd43dSSascha Wildner U32 const btLog = cParams->chainLog - 1;
380*a28cd43dSSascha Wildner U32 const btMask = (1 << btLog) - 1;
381*a28cd43dSSascha Wildner U32 matchIndex = hashTable[h];
382*a28cd43dSSascha Wildner size_t commonLengthSmaller=0, commonLengthLarger=0;
383*a28cd43dSSascha Wildner const BYTE* const base = ms->window.base;
384*a28cd43dSSascha Wildner const BYTE* const dictBase = ms->window.dictBase;
385*a28cd43dSSascha Wildner const U32 dictLimit = ms->window.dictLimit;
386*a28cd43dSSascha Wildner const BYTE* const dictEnd = dictBase + dictLimit;
387*a28cd43dSSascha Wildner const BYTE* const prefixStart = base + dictLimit;
388*a28cd43dSSascha Wildner const BYTE* match;
389*a28cd43dSSascha Wildner const U32 curr = (U32)(ip-base);
390*a28cd43dSSascha Wildner const U32 btLow = btMask >= curr ? 0 : curr - btMask;
391*a28cd43dSSascha Wildner U32* smallerPtr = bt + 2*(curr&btMask);
392*a28cd43dSSascha Wildner U32* largerPtr = smallerPtr + 1;
393*a28cd43dSSascha Wildner U32 dummy32; /* to be nullified at the end */
394*a28cd43dSSascha Wildner U32 const windowLow = ms->window.lowLimit;
395*a28cd43dSSascha Wildner U32 matchEndIdx = curr+8+1;
396*a28cd43dSSascha Wildner size_t bestLength = 8;
397*a28cd43dSSascha Wildner U32 nbCompares = 1U << cParams->searchLog;
398*a28cd43dSSascha Wildner #ifdef ZSTD_C_PREDICT
399*a28cd43dSSascha Wildner U32 predictedSmall = *(bt + 2*((curr-1)&btMask) + 0);
400*a28cd43dSSascha Wildner U32 predictedLarge = *(bt + 2*((curr-1)&btMask) + 1);
401*a28cd43dSSascha Wildner predictedSmall += (predictedSmall>0);
402*a28cd43dSSascha Wildner predictedLarge += (predictedLarge>0);
403*a28cd43dSSascha Wildner #endif /* ZSTD_C_PREDICT */
404*a28cd43dSSascha Wildner
405*a28cd43dSSascha Wildner DEBUGLOG(8, "ZSTD_insertBt1 (%u)", curr);
406*a28cd43dSSascha Wildner
407*a28cd43dSSascha Wildner assert(ip <= iend-8); /* required for h calculation */
408*a28cd43dSSascha Wildner hashTable[h] = curr; /* Update Hash Table */
409*a28cd43dSSascha Wildner
410*a28cd43dSSascha Wildner assert(windowLow > 0);
411*a28cd43dSSascha Wildner while (nbCompares-- && (matchIndex >= windowLow)) {
412*a28cd43dSSascha Wildner U32* const nextPtr = bt + 2*(matchIndex & btMask);
413*a28cd43dSSascha Wildner size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
414*a28cd43dSSascha Wildner assert(matchIndex < curr);
415*a28cd43dSSascha Wildner
416*a28cd43dSSascha Wildner #ifdef ZSTD_C_PREDICT /* note : can create issues when hlog small <= 11 */
417*a28cd43dSSascha Wildner const U32* predictPtr = bt + 2*((matchIndex-1) & btMask); /* written this way, as bt is a roll buffer */
418*a28cd43dSSascha Wildner if (matchIndex == predictedSmall) {
419*a28cd43dSSascha Wildner /* no need to check length, result known */
420*a28cd43dSSascha Wildner *smallerPtr = matchIndex;
421*a28cd43dSSascha Wildner if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */
422*a28cd43dSSascha Wildner smallerPtr = nextPtr+1; /* new "smaller" => larger of match */
423*a28cd43dSSascha Wildner matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */
424*a28cd43dSSascha Wildner predictedSmall = predictPtr[1] + (predictPtr[1]>0);
425*a28cd43dSSascha Wildner continue;
426*a28cd43dSSascha Wildner }
427*a28cd43dSSascha Wildner if (matchIndex == predictedLarge) {
428*a28cd43dSSascha Wildner *largerPtr = matchIndex;
429*a28cd43dSSascha Wildner if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */
430*a28cd43dSSascha Wildner largerPtr = nextPtr;
431*a28cd43dSSascha Wildner matchIndex = nextPtr[0];
432*a28cd43dSSascha Wildner predictedLarge = predictPtr[0] + (predictPtr[0]>0);
433*a28cd43dSSascha Wildner continue;
434*a28cd43dSSascha Wildner }
435*a28cd43dSSascha Wildner #endif
436*a28cd43dSSascha Wildner
437*a28cd43dSSascha Wildner if (!extDict || (matchIndex+matchLength >= dictLimit)) {
438*a28cd43dSSascha Wildner assert(matchIndex+matchLength >= dictLimit); /* might be wrong if actually extDict */
439*a28cd43dSSascha Wildner match = base + matchIndex;
440*a28cd43dSSascha Wildner matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend);
441*a28cd43dSSascha Wildner } else {
442*a28cd43dSSascha Wildner match = dictBase + matchIndex;
443*a28cd43dSSascha Wildner matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart);
444*a28cd43dSSascha Wildner if (matchIndex+matchLength >= dictLimit)
445*a28cd43dSSascha Wildner match = base + matchIndex; /* to prepare for next usage of match[matchLength] */
446*a28cd43dSSascha Wildner }
447*a28cd43dSSascha Wildner
448*a28cd43dSSascha Wildner if (matchLength > bestLength) {
449*a28cd43dSSascha Wildner bestLength = matchLength;
450*a28cd43dSSascha Wildner if (matchLength > matchEndIdx - matchIndex)
451*a28cd43dSSascha Wildner matchEndIdx = matchIndex + (U32)matchLength;
452*a28cd43dSSascha Wildner }
453*a28cd43dSSascha Wildner
454*a28cd43dSSascha Wildner if (ip+matchLength == iend) { /* equal : no way to know if inf or sup */
455*a28cd43dSSascha Wildner break; /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt tree */
456*a28cd43dSSascha Wildner }
457*a28cd43dSSascha Wildner
458*a28cd43dSSascha Wildner if (match[matchLength] < ip[matchLength]) { /* necessarily within buffer */
459*a28cd43dSSascha Wildner /* match is smaller than current */
460*a28cd43dSSascha Wildner *smallerPtr = matchIndex; /* update smaller idx */
461*a28cd43dSSascha Wildner commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
462*a28cd43dSSascha Wildner if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop searching */
463*a28cd43dSSascha Wildner smallerPtr = nextPtr+1; /* new "candidate" => larger than match, which was smaller than target */
464*a28cd43dSSascha Wildner matchIndex = nextPtr[1]; /* new matchIndex, larger than previous and closer to current */
465*a28cd43dSSascha Wildner } else {
466*a28cd43dSSascha Wildner /* match is larger than current */
467*a28cd43dSSascha Wildner *largerPtr = matchIndex;
468*a28cd43dSSascha Wildner commonLengthLarger = matchLength;
469*a28cd43dSSascha Wildner if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop searching */
470*a28cd43dSSascha Wildner largerPtr = nextPtr;
471*a28cd43dSSascha Wildner matchIndex = nextPtr[0];
472*a28cd43dSSascha Wildner } }
473*a28cd43dSSascha Wildner
474*a28cd43dSSascha Wildner *smallerPtr = *largerPtr = 0;
475*a28cd43dSSascha Wildner { U32 positions = 0;
476*a28cd43dSSascha Wildner if (bestLength > 384) positions = MIN(192, (U32)(bestLength - 384)); /* speed optimization */
477*a28cd43dSSascha Wildner assert(matchEndIdx > curr + 8);
478*a28cd43dSSascha Wildner return MAX(positions, matchEndIdx - (curr + 8));
479*a28cd43dSSascha Wildner }
480*a28cd43dSSascha Wildner }
481*a28cd43dSSascha Wildner
482*a28cd43dSSascha Wildner FORCE_INLINE_TEMPLATE
ZSTD_updateTree_internal(ZSTD_matchState_t * ms,const BYTE * const ip,const BYTE * const iend,const U32 mls,const ZSTD_dictMode_e dictMode)483*a28cd43dSSascha Wildner void ZSTD_updateTree_internal(
484*a28cd43dSSascha Wildner ZSTD_matchState_t* ms,
485*a28cd43dSSascha Wildner const BYTE* const ip, const BYTE* const iend,
486*a28cd43dSSascha Wildner const U32 mls, const ZSTD_dictMode_e dictMode)
487*a28cd43dSSascha Wildner {
488*a28cd43dSSascha Wildner const BYTE* const base = ms->window.base;
489*a28cd43dSSascha Wildner U32 const target = (U32)(ip - base);
490*a28cd43dSSascha Wildner U32 idx = ms->nextToUpdate;
491*a28cd43dSSascha Wildner DEBUGLOG(6, "ZSTD_updateTree_internal, from %u to %u (dictMode:%u)",
492*a28cd43dSSascha Wildner idx, target, dictMode);
493*a28cd43dSSascha Wildner
494*a28cd43dSSascha Wildner while(idx < target) {
495*a28cd43dSSascha Wildner U32 const forward = ZSTD_insertBt1(ms, base+idx, iend, mls, dictMode == ZSTD_extDict);
496*a28cd43dSSascha Wildner assert(idx < (U32)(idx + forward));
497*a28cd43dSSascha Wildner idx += forward;
498*a28cd43dSSascha Wildner }
499*a28cd43dSSascha Wildner assert((size_t)(ip - base) <= (size_t)(U32)(-1));
500*a28cd43dSSascha Wildner assert((size_t)(iend - base) <= (size_t)(U32)(-1));
501*a28cd43dSSascha Wildner ms->nextToUpdate = target;
502*a28cd43dSSascha Wildner }
503*a28cd43dSSascha Wildner
ZSTD_updateTree(ZSTD_matchState_t * ms,const BYTE * ip,const BYTE * iend)504*a28cd43dSSascha Wildner void ZSTD_updateTree(ZSTD_matchState_t* ms, const BYTE* ip, const BYTE* iend) {
505*a28cd43dSSascha Wildner ZSTD_updateTree_internal(ms, ip, iend, ms->cParams.minMatch, ZSTD_noDict);
506*a28cd43dSSascha Wildner }
507*a28cd43dSSascha Wildner
508*a28cd43dSSascha Wildner FORCE_INLINE_TEMPLATE
ZSTD_insertBtAndGetAllMatches(ZSTD_match_t * matches,ZSTD_matchState_t * ms,U32 * nextToUpdate3,const BYTE * const ip,const BYTE * const iLimit,const ZSTD_dictMode_e dictMode,const U32 rep[ZSTD_REP_NUM],U32 const ll0,const U32 lengthToBeat,U32 const mls)509*a28cd43dSSascha Wildner U32 ZSTD_insertBtAndGetAllMatches (
510*a28cd43dSSascha Wildner ZSTD_match_t* matches, /* store result (found matches) in this table (presumed large enough) */
511*a28cd43dSSascha Wildner ZSTD_matchState_t* ms,
512*a28cd43dSSascha Wildner U32* nextToUpdate3,
513*a28cd43dSSascha Wildner const BYTE* const ip, const BYTE* const iLimit, const ZSTD_dictMode_e dictMode,
514*a28cd43dSSascha Wildner const U32 rep[ZSTD_REP_NUM],
515*a28cd43dSSascha Wildner U32 const ll0, /* tells if associated literal length is 0 or not. This value must be 0 or 1 */
516*a28cd43dSSascha Wildner const U32 lengthToBeat,
517*a28cd43dSSascha Wildner U32 const mls /* template */)
518*a28cd43dSSascha Wildner {
519*a28cd43dSSascha Wildner const ZSTD_compressionParameters* const cParams = &ms->cParams;
520*a28cd43dSSascha Wildner U32 const sufficient_len = MIN(cParams->targetLength, ZSTD_OPT_NUM -1);
521*a28cd43dSSascha Wildner const BYTE* const base = ms->window.base;
522*a28cd43dSSascha Wildner U32 const curr = (U32)(ip-base);
523*a28cd43dSSascha Wildner U32 const hashLog = cParams->hashLog;
524*a28cd43dSSascha Wildner U32 const minMatch = (mls==3) ? 3 : 4;
525*a28cd43dSSascha Wildner U32* const hashTable = ms->hashTable;
526*a28cd43dSSascha Wildner size_t const h = ZSTD_hashPtr(ip, hashLog, mls);
527*a28cd43dSSascha Wildner U32 matchIndex = hashTable[h];
528*a28cd43dSSascha Wildner U32* const bt = ms->chainTable;
529*a28cd43dSSascha Wildner U32 const btLog = cParams->chainLog - 1;
530*a28cd43dSSascha Wildner U32 const btMask= (1U << btLog) - 1;
531*a28cd43dSSascha Wildner size_t commonLengthSmaller=0, commonLengthLarger=0;
532*a28cd43dSSascha Wildner const BYTE* const dictBase = ms->window.dictBase;
533*a28cd43dSSascha Wildner U32 const dictLimit = ms->window.dictLimit;
534*a28cd43dSSascha Wildner const BYTE* const dictEnd = dictBase + dictLimit;
535*a28cd43dSSascha Wildner const BYTE* const prefixStart = base + dictLimit;
536*a28cd43dSSascha Wildner U32 const btLow = (btMask >= curr) ? 0 : curr - btMask;
537*a28cd43dSSascha Wildner U32 const windowLow = ZSTD_getLowestMatchIndex(ms, curr, cParams->windowLog);
538*a28cd43dSSascha Wildner U32 const matchLow = windowLow ? windowLow : 1;
539*a28cd43dSSascha Wildner U32* smallerPtr = bt + 2*(curr&btMask);
540*a28cd43dSSascha Wildner U32* largerPtr = bt + 2*(curr&btMask) + 1;
541*a28cd43dSSascha Wildner U32 matchEndIdx = curr+8+1; /* farthest referenced position of any match => detects repetitive patterns */
542*a28cd43dSSascha Wildner U32 dummy32; /* to be nullified at the end */
543*a28cd43dSSascha Wildner U32 mnum = 0;
544*a28cd43dSSascha Wildner U32 nbCompares = 1U << cParams->searchLog;
545*a28cd43dSSascha Wildner
546*a28cd43dSSascha Wildner const ZSTD_matchState_t* dms = dictMode == ZSTD_dictMatchState ? ms->dictMatchState : NULL;
547*a28cd43dSSascha Wildner const ZSTD_compressionParameters* const dmsCParams =
548*a28cd43dSSascha Wildner dictMode == ZSTD_dictMatchState ? &dms->cParams : NULL;
549*a28cd43dSSascha Wildner const BYTE* const dmsBase = dictMode == ZSTD_dictMatchState ? dms->window.base : NULL;
550*a28cd43dSSascha Wildner const BYTE* const dmsEnd = dictMode == ZSTD_dictMatchState ? dms->window.nextSrc : NULL;
551*a28cd43dSSascha Wildner U32 const dmsHighLimit = dictMode == ZSTD_dictMatchState ? (U32)(dmsEnd - dmsBase) : 0;
552*a28cd43dSSascha Wildner U32 const dmsLowLimit = dictMode == ZSTD_dictMatchState ? dms->window.lowLimit : 0;
553*a28cd43dSSascha Wildner U32 const dmsIndexDelta = dictMode == ZSTD_dictMatchState ? windowLow - dmsHighLimit : 0;
554*a28cd43dSSascha Wildner U32 const dmsHashLog = dictMode == ZSTD_dictMatchState ? dmsCParams->hashLog : hashLog;
555*a28cd43dSSascha Wildner U32 const dmsBtLog = dictMode == ZSTD_dictMatchState ? dmsCParams->chainLog - 1 : btLog;
556*a28cd43dSSascha Wildner U32 const dmsBtMask = dictMode == ZSTD_dictMatchState ? (1U << dmsBtLog) - 1 : 0;
557*a28cd43dSSascha Wildner U32 const dmsBtLow = dictMode == ZSTD_dictMatchState && dmsBtMask < dmsHighLimit - dmsLowLimit ? dmsHighLimit - dmsBtMask : dmsLowLimit;
558*a28cd43dSSascha Wildner
559*a28cd43dSSascha Wildner size_t bestLength = lengthToBeat-1;
560*a28cd43dSSascha Wildner DEBUGLOG(8, "ZSTD_insertBtAndGetAllMatches: current=%u", curr);
561*a28cd43dSSascha Wildner
562*a28cd43dSSascha Wildner /* check repCode */
563*a28cd43dSSascha Wildner assert(ll0 <= 1); /* necessarily 1 or 0 */
564*a28cd43dSSascha Wildner { U32 const lastR = ZSTD_REP_NUM + ll0;
565*a28cd43dSSascha Wildner U32 repCode;
566*a28cd43dSSascha Wildner for (repCode = ll0; repCode < lastR; repCode++) {
567*a28cd43dSSascha Wildner U32 const repOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode];
568*a28cd43dSSascha Wildner U32 const repIndex = curr - repOffset;
569*a28cd43dSSascha Wildner U32 repLen = 0;
570*a28cd43dSSascha Wildner assert(curr >= dictLimit);
571*a28cd43dSSascha Wildner if (repOffset-1 /* intentional overflow, discards 0 and -1 */ < curr-dictLimit) { /* equivalent to `curr > repIndex >= dictLimit` */
572*a28cd43dSSascha Wildner /* We must validate the repcode offset because when we're using a dictionary the
573*a28cd43dSSascha Wildner * valid offset range shrinks when the dictionary goes out of bounds.
574*a28cd43dSSascha Wildner */
575*a28cd43dSSascha Wildner if ((repIndex >= windowLow) & (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(ip - repOffset, minMatch))) {
576*a28cd43dSSascha Wildner repLen = (U32)ZSTD_count(ip+minMatch, ip+minMatch-repOffset, iLimit) + minMatch;
577*a28cd43dSSascha Wildner }
578*a28cd43dSSascha Wildner } else { /* repIndex < dictLimit || repIndex >= curr */
579*a28cd43dSSascha Wildner const BYTE* const repMatch = dictMode == ZSTD_dictMatchState ?
580*a28cd43dSSascha Wildner dmsBase + repIndex - dmsIndexDelta :
581*a28cd43dSSascha Wildner dictBase + repIndex;
582*a28cd43dSSascha Wildner assert(curr >= windowLow);
583*a28cd43dSSascha Wildner if ( dictMode == ZSTD_extDict
584*a28cd43dSSascha Wildner && ( ((repOffset-1) /*intentional overflow*/ < curr - windowLow) /* equivalent to `curr > repIndex >= windowLow` */
585*a28cd43dSSascha Wildner & (((U32)((dictLimit-1) - repIndex) >= 3) ) /* intentional overflow : do not test positions overlapping 2 memory segments */)
586*a28cd43dSSascha Wildner && (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch)) ) {
587*a28cd43dSSascha Wildner repLen = (U32)ZSTD_count_2segments(ip+minMatch, repMatch+minMatch, iLimit, dictEnd, prefixStart) + minMatch;
588*a28cd43dSSascha Wildner }
589*a28cd43dSSascha Wildner if (dictMode == ZSTD_dictMatchState
590*a28cd43dSSascha Wildner && ( ((repOffset-1) /*intentional overflow*/ < curr - (dmsLowLimit + dmsIndexDelta)) /* equivalent to `curr > repIndex >= dmsLowLimit` */
591*a28cd43dSSascha Wildner & ((U32)((dictLimit-1) - repIndex) >= 3) ) /* intentional overflow : do not test positions overlapping 2 memory segments */
592*a28cd43dSSascha Wildner && (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch)) ) {
593*a28cd43dSSascha Wildner repLen = (U32)ZSTD_count_2segments(ip+minMatch, repMatch+minMatch, iLimit, dmsEnd, prefixStart) + minMatch;
594*a28cd43dSSascha Wildner } }
595*a28cd43dSSascha Wildner /* save longer solution */
596*a28cd43dSSascha Wildner if (repLen > bestLength) {
597*a28cd43dSSascha Wildner DEBUGLOG(8, "found repCode %u (ll0:%u, offset:%u) of length %u",
598*a28cd43dSSascha Wildner repCode, ll0, repOffset, repLen);
599*a28cd43dSSascha Wildner bestLength = repLen;
600*a28cd43dSSascha Wildner matches[mnum].off = repCode - ll0;
601*a28cd43dSSascha Wildner matches[mnum].len = (U32)repLen;
602*a28cd43dSSascha Wildner mnum++;
603*a28cd43dSSascha Wildner if ( (repLen > sufficient_len)
604*a28cd43dSSascha Wildner | (ip+repLen == iLimit) ) { /* best possible */
605*a28cd43dSSascha Wildner return mnum;
606*a28cd43dSSascha Wildner } } } }
607*a28cd43dSSascha Wildner
608*a28cd43dSSascha Wildner /* HC3 match finder */
609*a28cd43dSSascha Wildner if ((mls == 3) /*static*/ && (bestLength < mls)) {
610*a28cd43dSSascha Wildner U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3(ms, nextToUpdate3, ip);
611*a28cd43dSSascha Wildner if ((matchIndex3 >= matchLow)
612*a28cd43dSSascha Wildner & (curr - matchIndex3 < (1<<18)) /*heuristic : longer distance likely too expensive*/ ) {
613*a28cd43dSSascha Wildner size_t mlen;
614*a28cd43dSSascha Wildner if ((dictMode == ZSTD_noDict) /*static*/ || (dictMode == ZSTD_dictMatchState) /*static*/ || (matchIndex3 >= dictLimit)) {
615*a28cd43dSSascha Wildner const BYTE* const match = base + matchIndex3;
616*a28cd43dSSascha Wildner mlen = ZSTD_count(ip, match, iLimit);
617*a28cd43dSSascha Wildner } else {
618*a28cd43dSSascha Wildner const BYTE* const match = dictBase + matchIndex3;
619*a28cd43dSSascha Wildner mlen = ZSTD_count_2segments(ip, match, iLimit, dictEnd, prefixStart);
620*a28cd43dSSascha Wildner }
621*a28cd43dSSascha Wildner
622*a28cd43dSSascha Wildner /* save best solution */
623*a28cd43dSSascha Wildner if (mlen >= mls /* == 3 > bestLength */) {
624*a28cd43dSSascha Wildner DEBUGLOG(8, "found small match with hlog3, of length %u",
625*a28cd43dSSascha Wildner (U32)mlen);
626*a28cd43dSSascha Wildner bestLength = mlen;
627*a28cd43dSSascha Wildner assert(curr > matchIndex3);
628*a28cd43dSSascha Wildner assert(mnum==0); /* no prior solution */
629*a28cd43dSSascha Wildner matches[0].off = (curr - matchIndex3) + ZSTD_REP_MOVE;
630*a28cd43dSSascha Wildner matches[0].len = (U32)mlen;
631*a28cd43dSSascha Wildner mnum = 1;
632*a28cd43dSSascha Wildner if ( (mlen > sufficient_len) |
633*a28cd43dSSascha Wildner (ip+mlen == iLimit) ) { /* best possible length */
634*a28cd43dSSascha Wildner ms->nextToUpdate = curr+1; /* skip insertion */
635*a28cd43dSSascha Wildner return 1;
636*a28cd43dSSascha Wildner } } }
637*a28cd43dSSascha Wildner /* no dictMatchState lookup: dicts don't have a populated HC3 table */
638*a28cd43dSSascha Wildner }
639*a28cd43dSSascha Wildner
640*a28cd43dSSascha Wildner hashTable[h] = curr; /* Update Hash Table */
641*a28cd43dSSascha Wildner
642*a28cd43dSSascha Wildner while (nbCompares-- && (matchIndex >= matchLow)) {
643*a28cd43dSSascha Wildner U32* const nextPtr = bt + 2*(matchIndex & btMask);
644*a28cd43dSSascha Wildner const BYTE* match;
645*a28cd43dSSascha Wildner size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
646*a28cd43dSSascha Wildner assert(curr > matchIndex);
647*a28cd43dSSascha Wildner
648*a28cd43dSSascha Wildner if ((dictMode == ZSTD_noDict) || (dictMode == ZSTD_dictMatchState) || (matchIndex+matchLength >= dictLimit)) {
649*a28cd43dSSascha Wildner assert(matchIndex+matchLength >= dictLimit); /* ensure the condition is correct when !extDict */
650*a28cd43dSSascha Wildner match = base + matchIndex;
651*a28cd43dSSascha Wildner if (matchIndex >= dictLimit) assert(memcmp(match, ip, matchLength) == 0); /* ensure early section of match is equal as expected */
652*a28cd43dSSascha Wildner matchLength += ZSTD_count(ip+matchLength, match+matchLength, iLimit);
653*a28cd43dSSascha Wildner } else {
654*a28cd43dSSascha Wildner match = dictBase + matchIndex;
655*a28cd43dSSascha Wildner assert(memcmp(match, ip, matchLength) == 0); /* ensure early section of match is equal as expected */
656*a28cd43dSSascha Wildner matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iLimit, dictEnd, prefixStart);
657*a28cd43dSSascha Wildner if (matchIndex+matchLength >= dictLimit)
658*a28cd43dSSascha Wildner match = base + matchIndex; /* prepare for match[matchLength] read */
659*a28cd43dSSascha Wildner }
660*a28cd43dSSascha Wildner
661*a28cd43dSSascha Wildner if (matchLength > bestLength) {
662*a28cd43dSSascha Wildner DEBUGLOG(8, "found match of length %u at distance %u (offCode=%u)",
663*a28cd43dSSascha Wildner (U32)matchLength, curr - matchIndex, curr - matchIndex + ZSTD_REP_MOVE);
664*a28cd43dSSascha Wildner assert(matchEndIdx > matchIndex);
665*a28cd43dSSascha Wildner if (matchLength > matchEndIdx - matchIndex)
666*a28cd43dSSascha Wildner matchEndIdx = matchIndex + (U32)matchLength;
667*a28cd43dSSascha Wildner bestLength = matchLength;
668*a28cd43dSSascha Wildner matches[mnum].off = (curr - matchIndex) + ZSTD_REP_MOVE;
669*a28cd43dSSascha Wildner matches[mnum].len = (U32)matchLength;
670*a28cd43dSSascha Wildner mnum++;
671*a28cd43dSSascha Wildner if ( (matchLength > ZSTD_OPT_NUM)
672*a28cd43dSSascha Wildner | (ip+matchLength == iLimit) /* equal : no way to know if inf or sup */) {
673*a28cd43dSSascha Wildner if (dictMode == ZSTD_dictMatchState) nbCompares = 0; /* break should also skip searching dms */
674*a28cd43dSSascha Wildner break; /* drop, to preserve bt consistency (miss a little bit of compression) */
675*a28cd43dSSascha Wildner }
676*a28cd43dSSascha Wildner }
677*a28cd43dSSascha Wildner
678*a28cd43dSSascha Wildner if (match[matchLength] < ip[matchLength]) {
679*a28cd43dSSascha Wildner /* match smaller than current */
680*a28cd43dSSascha Wildner *smallerPtr = matchIndex; /* update smaller idx */
681*a28cd43dSSascha Wildner commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
682*a28cd43dSSascha Wildner if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */
683*a28cd43dSSascha Wildner smallerPtr = nextPtr+1; /* new candidate => larger than match, which was smaller than current */
684*a28cd43dSSascha Wildner matchIndex = nextPtr[1]; /* new matchIndex, larger than previous, closer to current */
685*a28cd43dSSascha Wildner } else {
686*a28cd43dSSascha Wildner *largerPtr = matchIndex;
687*a28cd43dSSascha Wildner commonLengthLarger = matchLength;
688*a28cd43dSSascha Wildner if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */
689*a28cd43dSSascha Wildner largerPtr = nextPtr;
690*a28cd43dSSascha Wildner matchIndex = nextPtr[0];
691*a28cd43dSSascha Wildner } }
692*a28cd43dSSascha Wildner
693*a28cd43dSSascha Wildner *smallerPtr = *largerPtr = 0;
694*a28cd43dSSascha Wildner
695*a28cd43dSSascha Wildner if (dictMode == ZSTD_dictMatchState && nbCompares) {
696*a28cd43dSSascha Wildner size_t const dmsH = ZSTD_hashPtr(ip, dmsHashLog, mls);
697*a28cd43dSSascha Wildner U32 dictMatchIndex = dms->hashTable[dmsH];
698*a28cd43dSSascha Wildner const U32* const dmsBt = dms->chainTable;
699*a28cd43dSSascha Wildner commonLengthSmaller = commonLengthLarger = 0;
700*a28cd43dSSascha Wildner while (nbCompares-- && (dictMatchIndex > dmsLowLimit)) {
701*a28cd43dSSascha Wildner const U32* const nextPtr = dmsBt + 2*(dictMatchIndex & dmsBtMask);
702*a28cd43dSSascha Wildner size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
703*a28cd43dSSascha Wildner const BYTE* match = dmsBase + dictMatchIndex;
704*a28cd43dSSascha Wildner matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iLimit, dmsEnd, prefixStart);
705*a28cd43dSSascha Wildner if (dictMatchIndex+matchLength >= dmsHighLimit)
706*a28cd43dSSascha Wildner match = base + dictMatchIndex + dmsIndexDelta; /* to prepare for next usage of match[matchLength] */
707*a28cd43dSSascha Wildner
708*a28cd43dSSascha Wildner if (matchLength > bestLength) {
709*a28cd43dSSascha Wildner matchIndex = dictMatchIndex + dmsIndexDelta;
710*a28cd43dSSascha Wildner DEBUGLOG(8, "found dms match of length %u at distance %u (offCode=%u)",
711*a28cd43dSSascha Wildner (U32)matchLength, curr - matchIndex, curr - matchIndex + ZSTD_REP_MOVE);
712*a28cd43dSSascha Wildner if (matchLength > matchEndIdx - matchIndex)
713*a28cd43dSSascha Wildner matchEndIdx = matchIndex + (U32)matchLength;
714*a28cd43dSSascha Wildner bestLength = matchLength;
715*a28cd43dSSascha Wildner matches[mnum].off = (curr - matchIndex) + ZSTD_REP_MOVE;
716*a28cd43dSSascha Wildner matches[mnum].len = (U32)matchLength;
717*a28cd43dSSascha Wildner mnum++;
718*a28cd43dSSascha Wildner if ( (matchLength > ZSTD_OPT_NUM)
719*a28cd43dSSascha Wildner | (ip+matchLength == iLimit) /* equal : no way to know if inf or sup */) {
720*a28cd43dSSascha Wildner break; /* drop, to guarantee consistency (miss a little bit of compression) */
721*a28cd43dSSascha Wildner }
722*a28cd43dSSascha Wildner }
723*a28cd43dSSascha Wildner
724*a28cd43dSSascha Wildner if (dictMatchIndex <= dmsBtLow) { break; } /* beyond tree size, stop the search */
725*a28cd43dSSascha Wildner if (match[matchLength] < ip[matchLength]) {
726*a28cd43dSSascha Wildner commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
727*a28cd43dSSascha Wildner dictMatchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */
728*a28cd43dSSascha Wildner } else {
729*a28cd43dSSascha Wildner /* match is larger than current */
730*a28cd43dSSascha Wildner commonLengthLarger = matchLength;
731*a28cd43dSSascha Wildner dictMatchIndex = nextPtr[0];
732*a28cd43dSSascha Wildner }
733*a28cd43dSSascha Wildner }
734*a28cd43dSSascha Wildner }
735*a28cd43dSSascha Wildner
736*a28cd43dSSascha Wildner assert(matchEndIdx > curr+8);
737*a28cd43dSSascha Wildner ms->nextToUpdate = matchEndIdx - 8; /* skip repetitive patterns */
738*a28cd43dSSascha Wildner return mnum;
739*a28cd43dSSascha Wildner }
740*a28cd43dSSascha Wildner
741*a28cd43dSSascha Wildner
ZSTD_BtGetAllMatches(ZSTD_match_t * matches,ZSTD_matchState_t * ms,U32 * nextToUpdate3,const BYTE * ip,const BYTE * const iHighLimit,const ZSTD_dictMode_e dictMode,const U32 rep[ZSTD_REP_NUM],U32 const ll0,U32 const lengthToBeat)742*a28cd43dSSascha Wildner FORCE_INLINE_TEMPLATE U32 ZSTD_BtGetAllMatches (
743*a28cd43dSSascha Wildner ZSTD_match_t* matches, /* store result (match found, increasing size) in this table */
744*a28cd43dSSascha Wildner ZSTD_matchState_t* ms,
745*a28cd43dSSascha Wildner U32* nextToUpdate3,
746*a28cd43dSSascha Wildner const BYTE* ip, const BYTE* const iHighLimit, const ZSTD_dictMode_e dictMode,
747*a28cd43dSSascha Wildner const U32 rep[ZSTD_REP_NUM],
748*a28cd43dSSascha Wildner U32 const ll0,
749*a28cd43dSSascha Wildner U32 const lengthToBeat)
750*a28cd43dSSascha Wildner {
751*a28cd43dSSascha Wildner const ZSTD_compressionParameters* const cParams = &ms->cParams;
752*a28cd43dSSascha Wildner U32 const matchLengthSearch = cParams->minMatch;
753*a28cd43dSSascha Wildner DEBUGLOG(8, "ZSTD_BtGetAllMatches");
754*a28cd43dSSascha Wildner if (ip < ms->window.base + ms->nextToUpdate) return 0; /* skipped area */
755*a28cd43dSSascha Wildner ZSTD_updateTree_internal(ms, ip, iHighLimit, matchLengthSearch, dictMode);
756*a28cd43dSSascha Wildner switch(matchLengthSearch)
757*a28cd43dSSascha Wildner {
758*a28cd43dSSascha Wildner case 3 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 3);
759*a28cd43dSSascha Wildner default :
760*a28cd43dSSascha Wildner case 4 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 4);
761*a28cd43dSSascha Wildner case 5 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 5);
762*a28cd43dSSascha Wildner case 7 :
763*a28cd43dSSascha Wildner case 6 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 6);
764*a28cd43dSSascha Wildner }
765*a28cd43dSSascha Wildner }
766*a28cd43dSSascha Wildner
767*a28cd43dSSascha Wildner /*************************
768*a28cd43dSSascha Wildner * LDM helper functions *
769*a28cd43dSSascha Wildner *************************/
770*a28cd43dSSascha Wildner
771*a28cd43dSSascha Wildner /* Struct containing info needed to make decision about ldm inclusion */
772*a28cd43dSSascha Wildner typedef struct {
773*a28cd43dSSascha Wildner rawSeqStore_t seqStore; /* External match candidates store for this block */
774*a28cd43dSSascha Wildner U32 startPosInBlock; /* Start position of the current match candidate */
775*a28cd43dSSascha Wildner U32 endPosInBlock; /* End position of the current match candidate */
776*a28cd43dSSascha Wildner U32 offset; /* Offset of the match candidate */
777*a28cd43dSSascha Wildner } ZSTD_optLdm_t;
778*a28cd43dSSascha Wildner
779*a28cd43dSSascha Wildner /* ZSTD_optLdm_skipRawSeqStoreBytes():
780*a28cd43dSSascha Wildner * Moves forward in rawSeqStore by nbBytes, which will update the fields 'pos' and 'posInSequence'.
781*a28cd43dSSascha Wildner */
ZSTD_optLdm_skipRawSeqStoreBytes(rawSeqStore_t * rawSeqStore,size_t nbBytes)782*a28cd43dSSascha Wildner static void ZSTD_optLdm_skipRawSeqStoreBytes(rawSeqStore_t* rawSeqStore, size_t nbBytes) {
783*a28cd43dSSascha Wildner U32 currPos = (U32)(rawSeqStore->posInSequence + nbBytes);
784*a28cd43dSSascha Wildner while (currPos && rawSeqStore->pos < rawSeqStore->size) {
785*a28cd43dSSascha Wildner rawSeq currSeq = rawSeqStore->seq[rawSeqStore->pos];
786*a28cd43dSSascha Wildner if (currPos >= currSeq.litLength + currSeq.matchLength) {
787*a28cd43dSSascha Wildner currPos -= currSeq.litLength + currSeq.matchLength;
788*a28cd43dSSascha Wildner rawSeqStore->pos++;
789*a28cd43dSSascha Wildner } else {
790*a28cd43dSSascha Wildner rawSeqStore->posInSequence = currPos;
791*a28cd43dSSascha Wildner break;
792*a28cd43dSSascha Wildner }
793*a28cd43dSSascha Wildner }
794*a28cd43dSSascha Wildner if (currPos == 0 || rawSeqStore->pos == rawSeqStore->size) {
795*a28cd43dSSascha Wildner rawSeqStore->posInSequence = 0;
796*a28cd43dSSascha Wildner }
797*a28cd43dSSascha Wildner }
798*a28cd43dSSascha Wildner
799*a28cd43dSSascha Wildner /* ZSTD_opt_getNextMatchAndUpdateSeqStore():
800*a28cd43dSSascha Wildner * Calculates the beginning and end of the next match in the current block.
801*a28cd43dSSascha Wildner * Updates 'pos' and 'posInSequence' of the ldmSeqStore.
802*a28cd43dSSascha Wildner */
ZSTD_opt_getNextMatchAndUpdateSeqStore(ZSTD_optLdm_t * optLdm,U32 currPosInBlock,U32 blockBytesRemaining)803*a28cd43dSSascha Wildner static void ZSTD_opt_getNextMatchAndUpdateSeqStore(ZSTD_optLdm_t* optLdm, U32 currPosInBlock,
804*a28cd43dSSascha Wildner U32 blockBytesRemaining) {
805*a28cd43dSSascha Wildner rawSeq currSeq;
806*a28cd43dSSascha Wildner U32 currBlockEndPos;
807*a28cd43dSSascha Wildner U32 literalsBytesRemaining;
808*a28cd43dSSascha Wildner U32 matchBytesRemaining;
809*a28cd43dSSascha Wildner
810*a28cd43dSSascha Wildner /* Setting match end position to MAX to ensure we never use an LDM during this block */
811*a28cd43dSSascha Wildner if (optLdm->seqStore.size == 0 || optLdm->seqStore.pos >= optLdm->seqStore.size) {
812*a28cd43dSSascha Wildner optLdm->startPosInBlock = UINT_MAX;
813*a28cd43dSSascha Wildner optLdm->endPosInBlock = UINT_MAX;
814*a28cd43dSSascha Wildner return;
815*a28cd43dSSascha Wildner }
816*a28cd43dSSascha Wildner /* Calculate appropriate bytes left in matchLength and litLength after adjusting
817*a28cd43dSSascha Wildner based on ldmSeqStore->posInSequence */
818*a28cd43dSSascha Wildner currSeq = optLdm->seqStore.seq[optLdm->seqStore.pos];
819*a28cd43dSSascha Wildner assert(optLdm->seqStore.posInSequence <= currSeq.litLength + currSeq.matchLength);
820*a28cd43dSSascha Wildner currBlockEndPos = currPosInBlock + blockBytesRemaining;
821*a28cd43dSSascha Wildner literalsBytesRemaining = (optLdm->seqStore.posInSequence < currSeq.litLength) ?
822*a28cd43dSSascha Wildner currSeq.litLength - (U32)optLdm->seqStore.posInSequence :
823*a28cd43dSSascha Wildner 0;
824*a28cd43dSSascha Wildner matchBytesRemaining = (literalsBytesRemaining == 0) ?
825*a28cd43dSSascha Wildner currSeq.matchLength - ((U32)optLdm->seqStore.posInSequence - currSeq.litLength) :
826*a28cd43dSSascha Wildner currSeq.matchLength;
827*a28cd43dSSascha Wildner
828*a28cd43dSSascha Wildner /* If there are more literal bytes than bytes remaining in block, no ldm is possible */
829*a28cd43dSSascha Wildner if (literalsBytesRemaining >= blockBytesRemaining) {
830*a28cd43dSSascha Wildner optLdm->startPosInBlock = UINT_MAX;
831*a28cd43dSSascha Wildner optLdm->endPosInBlock = UINT_MAX;
832*a28cd43dSSascha Wildner ZSTD_optLdm_skipRawSeqStoreBytes(&optLdm->seqStore, blockBytesRemaining);
833*a28cd43dSSascha Wildner return;
834*a28cd43dSSascha Wildner }
835*a28cd43dSSascha Wildner
836*a28cd43dSSascha Wildner /* Matches may be < MINMATCH by this process. In that case, we will reject them
837*a28cd43dSSascha Wildner when we are deciding whether or not to add the ldm */
838*a28cd43dSSascha Wildner optLdm->startPosInBlock = currPosInBlock + literalsBytesRemaining;
839*a28cd43dSSascha Wildner optLdm->endPosInBlock = optLdm->startPosInBlock + matchBytesRemaining;
840*a28cd43dSSascha Wildner optLdm->offset = currSeq.offset;
841*a28cd43dSSascha Wildner
842*a28cd43dSSascha Wildner if (optLdm->endPosInBlock > currBlockEndPos) {
843*a28cd43dSSascha Wildner /* Match ends after the block ends, we can't use the whole match */
844*a28cd43dSSascha Wildner optLdm->endPosInBlock = currBlockEndPos;
845*a28cd43dSSascha Wildner ZSTD_optLdm_skipRawSeqStoreBytes(&optLdm->seqStore, currBlockEndPos - currPosInBlock);
846*a28cd43dSSascha Wildner } else {
847*a28cd43dSSascha Wildner /* Consume nb of bytes equal to size of sequence left */
848*a28cd43dSSascha Wildner ZSTD_optLdm_skipRawSeqStoreBytes(&optLdm->seqStore, literalsBytesRemaining + matchBytesRemaining);
849*a28cd43dSSascha Wildner }
850*a28cd43dSSascha Wildner }
851*a28cd43dSSascha Wildner
852*a28cd43dSSascha Wildner /* ZSTD_optLdm_maybeAddMatch():
853*a28cd43dSSascha Wildner * Adds a match if it's long enough, based on it's 'matchStartPosInBlock'
854*a28cd43dSSascha Wildner * and 'matchEndPosInBlock', into 'matches'. Maintains the correct ordering of 'matches'
855*a28cd43dSSascha Wildner */
ZSTD_optLdm_maybeAddMatch(ZSTD_match_t * matches,U32 * nbMatches,ZSTD_optLdm_t * optLdm,U32 currPosInBlock)856*a28cd43dSSascha Wildner static void ZSTD_optLdm_maybeAddMatch(ZSTD_match_t* matches, U32* nbMatches,
857*a28cd43dSSascha Wildner ZSTD_optLdm_t* optLdm, U32 currPosInBlock) {
858*a28cd43dSSascha Wildner U32 posDiff = currPosInBlock - optLdm->startPosInBlock;
859*a28cd43dSSascha Wildner /* Note: ZSTD_match_t actually contains offCode and matchLength (before subtracting MINMATCH) */
860*a28cd43dSSascha Wildner U32 candidateMatchLength = optLdm->endPosInBlock - optLdm->startPosInBlock - posDiff;
861*a28cd43dSSascha Wildner U32 candidateOffCode = optLdm->offset + ZSTD_REP_MOVE;
862*a28cd43dSSascha Wildner
863*a28cd43dSSascha Wildner /* Ensure that current block position is not outside of the match */
864*a28cd43dSSascha Wildner if (currPosInBlock < optLdm->startPosInBlock
865*a28cd43dSSascha Wildner || currPosInBlock >= optLdm->endPosInBlock
866*a28cd43dSSascha Wildner || candidateMatchLength < MINMATCH) {
867*a28cd43dSSascha Wildner return;
868*a28cd43dSSascha Wildner }
869*a28cd43dSSascha Wildner
870*a28cd43dSSascha Wildner if (*nbMatches == 0 || ((candidateMatchLength > matches[*nbMatches-1].len) && *nbMatches < ZSTD_OPT_NUM)) {
871*a28cd43dSSascha Wildner DEBUGLOG(6, "ZSTD_optLdm_maybeAddMatch(): Adding ldm candidate match (offCode: %u matchLength %u) at block position=%u",
872*a28cd43dSSascha Wildner candidateOffCode, candidateMatchLength, currPosInBlock);
873*a28cd43dSSascha Wildner matches[*nbMatches].len = candidateMatchLength;
874*a28cd43dSSascha Wildner matches[*nbMatches].off = candidateOffCode;
875*a28cd43dSSascha Wildner (*nbMatches)++;
876*a28cd43dSSascha Wildner }
877*a28cd43dSSascha Wildner }
878*a28cd43dSSascha Wildner
879*a28cd43dSSascha Wildner /* ZSTD_optLdm_processMatchCandidate():
880*a28cd43dSSascha Wildner * Wrapper function to update ldm seq store and call ldm functions as necessary.
881*a28cd43dSSascha Wildner */
ZSTD_optLdm_processMatchCandidate(ZSTD_optLdm_t * optLdm,ZSTD_match_t * matches,U32 * nbMatches,U32 currPosInBlock,U32 remainingBytes)882*a28cd43dSSascha Wildner static void ZSTD_optLdm_processMatchCandidate(ZSTD_optLdm_t* optLdm, ZSTD_match_t* matches, U32* nbMatches,
883*a28cd43dSSascha Wildner U32 currPosInBlock, U32 remainingBytes) {
884*a28cd43dSSascha Wildner if (optLdm->seqStore.size == 0 || optLdm->seqStore.pos >= optLdm->seqStore.size) {
885*a28cd43dSSascha Wildner return;
886*a28cd43dSSascha Wildner }
887*a28cd43dSSascha Wildner
888*a28cd43dSSascha Wildner if (currPosInBlock >= optLdm->endPosInBlock) {
889*a28cd43dSSascha Wildner if (currPosInBlock > optLdm->endPosInBlock) {
890*a28cd43dSSascha Wildner /* The position at which ZSTD_optLdm_processMatchCandidate() is called is not necessarily
891*a28cd43dSSascha Wildner * at the end of a match from the ldm seq store, and will often be some bytes
892*a28cd43dSSascha Wildner * over beyond matchEndPosInBlock. As such, we need to correct for these "overshoots"
893*a28cd43dSSascha Wildner */
894*a28cd43dSSascha Wildner U32 posOvershoot = currPosInBlock - optLdm->endPosInBlock;
895*a28cd43dSSascha Wildner ZSTD_optLdm_skipRawSeqStoreBytes(&optLdm->seqStore, posOvershoot);
896*a28cd43dSSascha Wildner }
897*a28cd43dSSascha Wildner ZSTD_opt_getNextMatchAndUpdateSeqStore(optLdm, currPosInBlock, remainingBytes);
898*a28cd43dSSascha Wildner }
899*a28cd43dSSascha Wildner ZSTD_optLdm_maybeAddMatch(matches, nbMatches, optLdm, currPosInBlock);
900*a28cd43dSSascha Wildner }
901*a28cd43dSSascha Wildner
902*a28cd43dSSascha Wildner /*-*******************************
903*a28cd43dSSascha Wildner * Optimal parser
904*a28cd43dSSascha Wildner *********************************/
905*a28cd43dSSascha Wildner
906*a28cd43dSSascha Wildner
ZSTD_totalLen(ZSTD_optimal_t sol)907*a28cd43dSSascha Wildner static U32 ZSTD_totalLen(ZSTD_optimal_t sol)
908*a28cd43dSSascha Wildner {
909*a28cd43dSSascha Wildner return sol.litlen + sol.mlen;
910*a28cd43dSSascha Wildner }
911*a28cd43dSSascha Wildner
912*a28cd43dSSascha Wildner #if 0 /* debug */
913*a28cd43dSSascha Wildner
914*a28cd43dSSascha Wildner static void
915*a28cd43dSSascha Wildner listStats(const U32* table, int lastEltID)
916*a28cd43dSSascha Wildner {
917*a28cd43dSSascha Wildner int const nbElts = lastEltID + 1;
918*a28cd43dSSascha Wildner int enb;
919*a28cd43dSSascha Wildner for (enb=0; enb < nbElts; enb++) {
920*a28cd43dSSascha Wildner (void)table;
921*a28cd43dSSascha Wildner /* RAWLOG(2, "%3i:%3i, ", enb, table[enb]); */
922*a28cd43dSSascha Wildner RAWLOG(2, "%4i,", table[enb]);
923*a28cd43dSSascha Wildner }
924*a28cd43dSSascha Wildner RAWLOG(2, " \n");
925*a28cd43dSSascha Wildner }
926*a28cd43dSSascha Wildner
927*a28cd43dSSascha Wildner #endif
928*a28cd43dSSascha Wildner
929*a28cd43dSSascha Wildner 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)930*a28cd43dSSascha Wildner ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
931*a28cd43dSSascha Wildner seqStore_t* seqStore,
932*a28cd43dSSascha Wildner U32 rep[ZSTD_REP_NUM],
933*a28cd43dSSascha Wildner const void* src, size_t srcSize,
934*a28cd43dSSascha Wildner const int optLevel,
935*a28cd43dSSascha Wildner const ZSTD_dictMode_e dictMode)
936*a28cd43dSSascha Wildner {
937*a28cd43dSSascha Wildner optState_t* const optStatePtr = &ms->opt;
938*a28cd43dSSascha Wildner const BYTE* const istart = (const BYTE*)src;
939*a28cd43dSSascha Wildner const BYTE* ip = istart;
940*a28cd43dSSascha Wildner const BYTE* anchor = istart;
941*a28cd43dSSascha Wildner const BYTE* const iend = istart + srcSize;
942*a28cd43dSSascha Wildner const BYTE* const ilimit = iend - 8;
943*a28cd43dSSascha Wildner const BYTE* const base = ms->window.base;
944*a28cd43dSSascha Wildner const BYTE* const prefixStart = base + ms->window.dictLimit;
945*a28cd43dSSascha Wildner const ZSTD_compressionParameters* const cParams = &ms->cParams;
946*a28cd43dSSascha Wildner
947*a28cd43dSSascha Wildner U32 const sufficient_len = MIN(cParams->targetLength, ZSTD_OPT_NUM -1);
948*a28cd43dSSascha Wildner U32 const minMatch = (cParams->minMatch == 3) ? 3 : 4;
949*a28cd43dSSascha Wildner U32 nextToUpdate3 = ms->nextToUpdate;
950*a28cd43dSSascha Wildner
951*a28cd43dSSascha Wildner ZSTD_optimal_t* const opt = optStatePtr->priceTable;
952*a28cd43dSSascha Wildner ZSTD_match_t* const matches = optStatePtr->matchTable;
953*a28cd43dSSascha Wildner ZSTD_optimal_t lastSequence;
954*a28cd43dSSascha Wildner ZSTD_optLdm_t optLdm;
955*a28cd43dSSascha Wildner
956*a28cd43dSSascha Wildner optLdm.seqStore = ms->ldmSeqStore ? *ms->ldmSeqStore : kNullRawSeqStore;
957*a28cd43dSSascha Wildner optLdm.endPosInBlock = optLdm.startPosInBlock = optLdm.offset = 0;
958*a28cd43dSSascha Wildner ZSTD_opt_getNextMatchAndUpdateSeqStore(&optLdm, (U32)(ip-istart), (U32)(iend-ip));
959*a28cd43dSSascha Wildner
960*a28cd43dSSascha Wildner /* init */
961*a28cd43dSSascha Wildner DEBUGLOG(5, "ZSTD_compressBlock_opt_generic: current=%u, prefix=%u, nextToUpdate=%u",
962*a28cd43dSSascha Wildner (U32)(ip - base), ms->window.dictLimit, ms->nextToUpdate);
963*a28cd43dSSascha Wildner assert(optLevel <= 2);
964*a28cd43dSSascha Wildner ZSTD_rescaleFreqs(optStatePtr, (const BYTE*)src, srcSize, optLevel);
965*a28cd43dSSascha Wildner ip += (ip==prefixStart);
966*a28cd43dSSascha Wildner
967*a28cd43dSSascha Wildner /* Match Loop */
968*a28cd43dSSascha Wildner while (ip < ilimit) {
969*a28cd43dSSascha Wildner U32 cur, last_pos = 0;
970*a28cd43dSSascha Wildner
971*a28cd43dSSascha Wildner /* find first match */
972*a28cd43dSSascha Wildner { U32 const litlen = (U32)(ip - anchor);
973*a28cd43dSSascha Wildner U32 const ll0 = !litlen;
974*a28cd43dSSascha Wildner U32 nbMatches = ZSTD_BtGetAllMatches(matches, ms, &nextToUpdate3, ip, iend, dictMode, rep, ll0, minMatch);
975*a28cd43dSSascha Wildner ZSTD_optLdm_processMatchCandidate(&optLdm, matches, &nbMatches,
976*a28cd43dSSascha Wildner (U32)(ip-istart), (U32)(iend - ip));
977*a28cd43dSSascha Wildner if (!nbMatches) { ip++; continue; }
978*a28cd43dSSascha Wildner
979*a28cd43dSSascha Wildner /* initialize opt[0] */
980*a28cd43dSSascha Wildner { U32 i ; for (i=0; i<ZSTD_REP_NUM; i++) opt[0].rep[i] = rep[i]; }
981*a28cd43dSSascha Wildner opt[0].mlen = 0; /* means is_a_literal */
982*a28cd43dSSascha Wildner opt[0].litlen = litlen;
983*a28cd43dSSascha Wildner /* We don't need to include the actual price of the literals because
984*a28cd43dSSascha Wildner * it is static for the duration of the forward pass, and is included
985*a28cd43dSSascha Wildner * in every price. We include the literal length to avoid negative
986*a28cd43dSSascha Wildner * prices when we subtract the previous literal length.
987*a28cd43dSSascha Wildner */
988*a28cd43dSSascha Wildner opt[0].price = ZSTD_litLengthPrice(litlen, optStatePtr, optLevel);
989*a28cd43dSSascha Wildner
990*a28cd43dSSascha Wildner /* large match -> immediate encoding */
991*a28cd43dSSascha Wildner { U32 const maxML = matches[nbMatches-1].len;
992*a28cd43dSSascha Wildner U32 const maxOffset = matches[nbMatches-1].off;
993*a28cd43dSSascha Wildner DEBUGLOG(6, "found %u matches of maxLength=%u and maxOffCode=%u at cPos=%u => start new series",
994*a28cd43dSSascha Wildner nbMatches, maxML, maxOffset, (U32)(ip-prefixStart));
995*a28cd43dSSascha Wildner
996*a28cd43dSSascha Wildner if (maxML > sufficient_len) {
997*a28cd43dSSascha Wildner lastSequence.litlen = litlen;
998*a28cd43dSSascha Wildner lastSequence.mlen = maxML;
999*a28cd43dSSascha Wildner lastSequence.off = maxOffset;
1000*a28cd43dSSascha Wildner DEBUGLOG(6, "large match (%u>%u), immediate encoding",
1001*a28cd43dSSascha Wildner maxML, sufficient_len);
1002*a28cd43dSSascha Wildner cur = 0;
1003*a28cd43dSSascha Wildner last_pos = ZSTD_totalLen(lastSequence);
1004*a28cd43dSSascha Wildner goto _shortestPath;
1005*a28cd43dSSascha Wildner } }
1006*a28cd43dSSascha Wildner
1007*a28cd43dSSascha Wildner /* set prices for first matches starting position == 0 */
1008*a28cd43dSSascha Wildner { U32 const literalsPrice = opt[0].price + ZSTD_litLengthPrice(0, optStatePtr, optLevel);
1009*a28cd43dSSascha Wildner U32 pos;
1010*a28cd43dSSascha Wildner U32 matchNb;
1011*a28cd43dSSascha Wildner for (pos = 1; pos < minMatch; pos++) {
1012*a28cd43dSSascha Wildner opt[pos].price = ZSTD_MAX_PRICE; /* mlen, litlen and price will be fixed during forward scanning */
1013*a28cd43dSSascha Wildner }
1014*a28cd43dSSascha Wildner for (matchNb = 0; matchNb < nbMatches; matchNb++) {
1015*a28cd43dSSascha Wildner U32 const offset = matches[matchNb].off;
1016*a28cd43dSSascha Wildner U32 const end = matches[matchNb].len;
1017*a28cd43dSSascha Wildner for ( ; pos <= end ; pos++ ) {
1018*a28cd43dSSascha Wildner U32 const matchPrice = ZSTD_getMatchPrice(offset, pos, optStatePtr, optLevel);
1019*a28cd43dSSascha Wildner U32 const sequencePrice = literalsPrice + matchPrice;
1020*a28cd43dSSascha Wildner DEBUGLOG(7, "rPos:%u => set initial price : %.2f",
1021*a28cd43dSSascha Wildner pos, ZSTD_fCost(sequencePrice));
1022*a28cd43dSSascha Wildner opt[pos].mlen = pos;
1023*a28cd43dSSascha Wildner opt[pos].off = offset;
1024*a28cd43dSSascha Wildner opt[pos].litlen = litlen;
1025*a28cd43dSSascha Wildner opt[pos].price = sequencePrice;
1026*a28cd43dSSascha Wildner } }
1027*a28cd43dSSascha Wildner last_pos = pos-1;
1028*a28cd43dSSascha Wildner }
1029*a28cd43dSSascha Wildner }
1030*a28cd43dSSascha Wildner
1031*a28cd43dSSascha Wildner /* check further positions */
1032*a28cd43dSSascha Wildner for (cur = 1; cur <= last_pos; cur++) {
1033*a28cd43dSSascha Wildner const BYTE* const inr = ip + cur;
1034*a28cd43dSSascha Wildner assert(cur < ZSTD_OPT_NUM);
1035*a28cd43dSSascha Wildner DEBUGLOG(7, "cPos:%zi==rPos:%u", inr-istart, cur)
1036*a28cd43dSSascha Wildner
1037*a28cd43dSSascha Wildner /* Fix current position with one literal if cheaper */
1038*a28cd43dSSascha Wildner { U32 const litlen = (opt[cur-1].mlen == 0) ? opt[cur-1].litlen + 1 : 1;
1039*a28cd43dSSascha Wildner int const price = opt[cur-1].price
1040*a28cd43dSSascha Wildner + ZSTD_rawLiteralsCost(ip+cur-1, 1, optStatePtr, optLevel)
1041*a28cd43dSSascha Wildner + ZSTD_litLengthPrice(litlen, optStatePtr, optLevel)
1042*a28cd43dSSascha Wildner - ZSTD_litLengthPrice(litlen-1, optStatePtr, optLevel);
1043*a28cd43dSSascha Wildner assert(price < 1000000000); /* overflow check */
1044*a28cd43dSSascha Wildner if (price <= opt[cur].price) {
1045*a28cd43dSSascha Wildner DEBUGLOG(7, "cPos:%zi==rPos:%u : better price (%.2f<=%.2f) using literal (ll==%u) (hist:%u,%u,%u)",
1046*a28cd43dSSascha Wildner inr-istart, cur, ZSTD_fCost(price), ZSTD_fCost(opt[cur].price), litlen,
1047*a28cd43dSSascha Wildner opt[cur-1].rep[0], opt[cur-1].rep[1], opt[cur-1].rep[2]);
1048*a28cd43dSSascha Wildner opt[cur].mlen = 0;
1049*a28cd43dSSascha Wildner opt[cur].off = 0;
1050*a28cd43dSSascha Wildner opt[cur].litlen = litlen;
1051*a28cd43dSSascha Wildner opt[cur].price = price;
1052*a28cd43dSSascha Wildner } else {
1053*a28cd43dSSascha Wildner DEBUGLOG(7, "cPos:%zi==rPos:%u : literal would cost more (%.2f>%.2f) (hist:%u,%u,%u)",
1054*a28cd43dSSascha Wildner inr-istart, cur, ZSTD_fCost(price), ZSTD_fCost(opt[cur].price),
1055*a28cd43dSSascha Wildner opt[cur].rep[0], opt[cur].rep[1], opt[cur].rep[2]);
1056*a28cd43dSSascha Wildner }
1057*a28cd43dSSascha Wildner }
1058*a28cd43dSSascha Wildner
1059*a28cd43dSSascha Wildner /* Set the repcodes of the current position. We must do it here
1060*a28cd43dSSascha Wildner * because we rely on the repcodes of the 2nd to last sequence being
1061*a28cd43dSSascha Wildner * correct to set the next chunks repcodes during the backward
1062*a28cd43dSSascha Wildner * traversal.
1063*a28cd43dSSascha Wildner */
1064*a28cd43dSSascha Wildner ZSTD_STATIC_ASSERT(sizeof(opt[cur].rep) == sizeof(repcodes_t));
1065*a28cd43dSSascha Wildner assert(cur >= opt[cur].mlen);
1066*a28cd43dSSascha Wildner if (opt[cur].mlen != 0) {
1067*a28cd43dSSascha Wildner U32 const prev = cur - opt[cur].mlen;
1068*a28cd43dSSascha Wildner repcodes_t newReps = ZSTD_updateRep(opt[prev].rep, opt[cur].off, opt[cur].litlen==0);
1069*a28cd43dSSascha Wildner ZSTD_memcpy(opt[cur].rep, &newReps, sizeof(repcodes_t));
1070*a28cd43dSSascha Wildner } else {
1071*a28cd43dSSascha Wildner ZSTD_memcpy(opt[cur].rep, opt[cur - 1].rep, sizeof(repcodes_t));
1072*a28cd43dSSascha Wildner }
1073*a28cd43dSSascha Wildner
1074*a28cd43dSSascha Wildner /* last match must start at a minimum distance of 8 from oend */
1075*a28cd43dSSascha Wildner if (inr > ilimit) continue;
1076*a28cd43dSSascha Wildner
1077*a28cd43dSSascha Wildner if (cur == last_pos) break;
1078*a28cd43dSSascha Wildner
1079*a28cd43dSSascha Wildner if ( (optLevel==0) /*static_test*/
1080*a28cd43dSSascha Wildner && (opt[cur+1].price <= opt[cur].price + (BITCOST_MULTIPLIER/2)) ) {
1081*a28cd43dSSascha Wildner DEBUGLOG(7, "move to next rPos:%u : price is <=", cur+1);
1082*a28cd43dSSascha Wildner continue; /* skip unpromising positions; about ~+6% speed, -0.01 ratio */
1083*a28cd43dSSascha Wildner }
1084*a28cd43dSSascha Wildner
1085*a28cd43dSSascha Wildner { U32 const ll0 = (opt[cur].mlen != 0);
1086*a28cd43dSSascha Wildner U32 const litlen = (opt[cur].mlen == 0) ? opt[cur].litlen : 0;
1087*a28cd43dSSascha Wildner U32 const previousPrice = opt[cur].price;
1088*a28cd43dSSascha Wildner U32 const basePrice = previousPrice + ZSTD_litLengthPrice(0, optStatePtr, optLevel);
1089*a28cd43dSSascha Wildner U32 nbMatches = ZSTD_BtGetAllMatches(matches, ms, &nextToUpdate3, inr, iend, dictMode, opt[cur].rep, ll0, minMatch);
1090*a28cd43dSSascha Wildner U32 matchNb;
1091*a28cd43dSSascha Wildner
1092*a28cd43dSSascha Wildner ZSTD_optLdm_processMatchCandidate(&optLdm, matches, &nbMatches,
1093*a28cd43dSSascha Wildner (U32)(inr-istart), (U32)(iend-inr));
1094*a28cd43dSSascha Wildner
1095*a28cd43dSSascha Wildner if (!nbMatches) {
1096*a28cd43dSSascha Wildner DEBUGLOG(7, "rPos:%u : no match found", cur);
1097*a28cd43dSSascha Wildner continue;
1098*a28cd43dSSascha Wildner }
1099*a28cd43dSSascha Wildner
1100*a28cd43dSSascha Wildner { U32 const maxML = matches[nbMatches-1].len;
1101*a28cd43dSSascha Wildner DEBUGLOG(7, "cPos:%zi==rPos:%u, found %u matches, of maxLength=%u",
1102*a28cd43dSSascha Wildner inr-istart, cur, nbMatches, maxML);
1103*a28cd43dSSascha Wildner
1104*a28cd43dSSascha Wildner if ( (maxML > sufficient_len)
1105*a28cd43dSSascha Wildner || (cur + maxML >= ZSTD_OPT_NUM) ) {
1106*a28cd43dSSascha Wildner lastSequence.mlen = maxML;
1107*a28cd43dSSascha Wildner lastSequence.off = matches[nbMatches-1].off;
1108*a28cd43dSSascha Wildner lastSequence.litlen = litlen;
1109*a28cd43dSSascha Wildner 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 */
1110*a28cd43dSSascha Wildner last_pos = cur + ZSTD_totalLen(lastSequence);
1111*a28cd43dSSascha Wildner if (cur > ZSTD_OPT_NUM) cur = 0; /* underflow => first match */
1112*a28cd43dSSascha Wildner goto _shortestPath;
1113*a28cd43dSSascha Wildner } }
1114*a28cd43dSSascha Wildner
1115*a28cd43dSSascha Wildner /* set prices using matches found at position == cur */
1116*a28cd43dSSascha Wildner for (matchNb = 0; matchNb < nbMatches; matchNb++) {
1117*a28cd43dSSascha Wildner U32 const offset = matches[matchNb].off;
1118*a28cd43dSSascha Wildner U32 const lastML = matches[matchNb].len;
1119*a28cd43dSSascha Wildner U32 const startML = (matchNb>0) ? matches[matchNb-1].len+1 : minMatch;
1120*a28cd43dSSascha Wildner U32 mlen;
1121*a28cd43dSSascha Wildner
1122*a28cd43dSSascha Wildner DEBUGLOG(7, "testing match %u => offCode=%4u, mlen=%2u, llen=%2u",
1123*a28cd43dSSascha Wildner matchNb, matches[matchNb].off, lastML, litlen);
1124*a28cd43dSSascha Wildner
1125*a28cd43dSSascha Wildner for (mlen = lastML; mlen >= startML; mlen--) { /* scan downward */
1126*a28cd43dSSascha Wildner U32 const pos = cur + mlen;
1127*a28cd43dSSascha Wildner int const price = basePrice + ZSTD_getMatchPrice(offset, mlen, optStatePtr, optLevel);
1128*a28cd43dSSascha Wildner
1129*a28cd43dSSascha Wildner if ((pos > last_pos) || (price < opt[pos].price)) {
1130*a28cd43dSSascha Wildner DEBUGLOG(7, "rPos:%u (ml=%2u) => new better price (%.2f<%.2f)",
1131*a28cd43dSSascha Wildner pos, mlen, ZSTD_fCost(price), ZSTD_fCost(opt[pos].price));
1132*a28cd43dSSascha Wildner while (last_pos < pos) { opt[last_pos+1].price = ZSTD_MAX_PRICE; last_pos++; } /* fill empty positions */
1133*a28cd43dSSascha Wildner opt[pos].mlen = mlen;
1134*a28cd43dSSascha Wildner opt[pos].off = offset;
1135*a28cd43dSSascha Wildner opt[pos].litlen = litlen;
1136*a28cd43dSSascha Wildner opt[pos].price = price;
1137*a28cd43dSSascha Wildner } else {
1138*a28cd43dSSascha Wildner DEBUGLOG(7, "rPos:%u (ml=%2u) => new price is worse (%.2f>=%.2f)",
1139*a28cd43dSSascha Wildner pos, mlen, ZSTD_fCost(price), ZSTD_fCost(opt[pos].price));
1140*a28cd43dSSascha Wildner if (optLevel==0) break; /* early update abort; gets ~+10% speed for about -0.01 ratio loss */
1141*a28cd43dSSascha Wildner }
1142*a28cd43dSSascha Wildner } } }
1143*a28cd43dSSascha Wildner } /* for (cur = 1; cur <= last_pos; cur++) */
1144*a28cd43dSSascha Wildner
1145*a28cd43dSSascha Wildner lastSequence = opt[last_pos];
1146*a28cd43dSSascha Wildner cur = last_pos > ZSTD_totalLen(lastSequence) ? last_pos - ZSTD_totalLen(lastSequence) : 0; /* single sequence, and it starts before `ip` */
1147*a28cd43dSSascha Wildner assert(cur < ZSTD_OPT_NUM); /* control overflow*/
1148*a28cd43dSSascha Wildner
1149*a28cd43dSSascha Wildner _shortestPath: /* cur, last_pos, best_mlen, best_off have to be set */
1150*a28cd43dSSascha Wildner assert(opt[0].mlen == 0);
1151*a28cd43dSSascha Wildner
1152*a28cd43dSSascha Wildner /* Set the next chunk's repcodes based on the repcodes of the beginning
1153*a28cd43dSSascha Wildner * of the last match, and the last sequence. This avoids us having to
1154*a28cd43dSSascha Wildner * update them while traversing the sequences.
1155*a28cd43dSSascha Wildner */
1156*a28cd43dSSascha Wildner if (lastSequence.mlen != 0) {
1157*a28cd43dSSascha Wildner repcodes_t reps = ZSTD_updateRep(opt[cur].rep, lastSequence.off, lastSequence.litlen==0);
1158*a28cd43dSSascha Wildner ZSTD_memcpy(rep, &reps, sizeof(reps));
1159*a28cd43dSSascha Wildner } else {
1160*a28cd43dSSascha Wildner ZSTD_memcpy(rep, opt[cur].rep, sizeof(repcodes_t));
1161*a28cd43dSSascha Wildner }
1162*a28cd43dSSascha Wildner
1163*a28cd43dSSascha Wildner { U32 const storeEnd = cur + 1;
1164*a28cd43dSSascha Wildner U32 storeStart = storeEnd;
1165*a28cd43dSSascha Wildner U32 seqPos = cur;
1166*a28cd43dSSascha Wildner
1167*a28cd43dSSascha Wildner DEBUGLOG(6, "start reverse traversal (last_pos:%u, cur:%u)",
1168*a28cd43dSSascha Wildner last_pos, cur); (void)last_pos;
1169*a28cd43dSSascha Wildner assert(storeEnd < ZSTD_OPT_NUM);
1170*a28cd43dSSascha Wildner DEBUGLOG(6, "last sequence copied into pos=%u (llen=%u,mlen=%u,ofc=%u)",
1171*a28cd43dSSascha Wildner storeEnd, lastSequence.litlen, lastSequence.mlen, lastSequence.off);
1172*a28cd43dSSascha Wildner opt[storeEnd] = lastSequence;
1173*a28cd43dSSascha Wildner while (seqPos > 0) {
1174*a28cd43dSSascha Wildner U32 const backDist = ZSTD_totalLen(opt[seqPos]);
1175*a28cd43dSSascha Wildner storeStart--;
1176*a28cd43dSSascha Wildner DEBUGLOG(6, "sequence from rPos=%u copied into pos=%u (llen=%u,mlen=%u,ofc=%u)",
1177*a28cd43dSSascha Wildner seqPos, storeStart, opt[seqPos].litlen, opt[seqPos].mlen, opt[seqPos].off);
1178*a28cd43dSSascha Wildner opt[storeStart] = opt[seqPos];
1179*a28cd43dSSascha Wildner seqPos = (seqPos > backDist) ? seqPos - backDist : 0;
1180*a28cd43dSSascha Wildner }
1181*a28cd43dSSascha Wildner
1182*a28cd43dSSascha Wildner /* save sequences */
1183*a28cd43dSSascha Wildner DEBUGLOG(6, "sending selected sequences into seqStore")
1184*a28cd43dSSascha Wildner { U32 storePos;
1185*a28cd43dSSascha Wildner for (storePos=storeStart; storePos <= storeEnd; storePos++) {
1186*a28cd43dSSascha Wildner U32 const llen = opt[storePos].litlen;
1187*a28cd43dSSascha Wildner U32 const mlen = opt[storePos].mlen;
1188*a28cd43dSSascha Wildner U32 const offCode = opt[storePos].off;
1189*a28cd43dSSascha Wildner U32 const advance = llen + mlen;
1190*a28cd43dSSascha Wildner DEBUGLOG(6, "considering seq starting at %zi, llen=%u, mlen=%u",
1191*a28cd43dSSascha Wildner anchor - istart, (unsigned)llen, (unsigned)mlen);
1192*a28cd43dSSascha Wildner
1193*a28cd43dSSascha Wildner if (mlen==0) { /* only literals => must be last "sequence", actually starting a new stream of sequences */
1194*a28cd43dSSascha Wildner assert(storePos == storeEnd); /* must be last sequence */
1195*a28cd43dSSascha Wildner ip = anchor + llen; /* last "sequence" is a bunch of literals => don't progress anchor */
1196*a28cd43dSSascha Wildner continue; /* will finish */
1197*a28cd43dSSascha Wildner }
1198*a28cd43dSSascha Wildner
1199*a28cd43dSSascha Wildner assert(anchor + llen <= iend);
1200*a28cd43dSSascha Wildner ZSTD_updateStats(optStatePtr, llen, anchor, offCode, mlen);
1201*a28cd43dSSascha Wildner ZSTD_storeSeq(seqStore, llen, anchor, iend, offCode, mlen-MINMATCH);
1202*a28cd43dSSascha Wildner anchor += advance;
1203*a28cd43dSSascha Wildner ip = anchor;
1204*a28cd43dSSascha Wildner } }
1205*a28cd43dSSascha Wildner ZSTD_setBasePrices(optStatePtr, optLevel);
1206*a28cd43dSSascha Wildner }
1207*a28cd43dSSascha Wildner } /* while (ip < ilimit) */
1208*a28cd43dSSascha Wildner
1209*a28cd43dSSascha Wildner /* Return the last literals size */
1210*a28cd43dSSascha Wildner return (size_t)(iend - anchor);
1211*a28cd43dSSascha Wildner }
1212*a28cd43dSSascha Wildner
1213*a28cd43dSSascha Wildner
ZSTD_compressBlock_btopt(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],const void * src,size_t srcSize)1214*a28cd43dSSascha Wildner size_t ZSTD_compressBlock_btopt(
1215*a28cd43dSSascha Wildner ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
1216*a28cd43dSSascha Wildner const void* src, size_t srcSize)
1217*a28cd43dSSascha Wildner {
1218*a28cd43dSSascha Wildner DEBUGLOG(5, "ZSTD_compressBlock_btopt");
1219*a28cd43dSSascha Wildner return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_noDict);
1220*a28cd43dSSascha Wildner }
1221*a28cd43dSSascha Wildner
1222*a28cd43dSSascha Wildner
1223*a28cd43dSSascha Wildner /* used in 2-pass strategy */
ZSTD_upscaleStat(unsigned * table,U32 lastEltIndex,int bonus)1224*a28cd43dSSascha Wildner static U32 ZSTD_upscaleStat(unsigned* table, U32 lastEltIndex, int bonus)
1225*a28cd43dSSascha Wildner {
1226*a28cd43dSSascha Wildner U32 s, sum=0;
1227*a28cd43dSSascha Wildner assert(ZSTD_FREQ_DIV+bonus >= 0);
1228*a28cd43dSSascha Wildner for (s=0; s<lastEltIndex+1; s++) {
1229*a28cd43dSSascha Wildner table[s] <<= ZSTD_FREQ_DIV+bonus;
1230*a28cd43dSSascha Wildner table[s]--;
1231*a28cd43dSSascha Wildner sum += table[s];
1232*a28cd43dSSascha Wildner }
1233*a28cd43dSSascha Wildner return sum;
1234*a28cd43dSSascha Wildner }
1235*a28cd43dSSascha Wildner
1236*a28cd43dSSascha Wildner /* used in 2-pass strategy */
ZSTD_upscaleStats(optState_t * optPtr)1237*a28cd43dSSascha Wildner MEM_STATIC void ZSTD_upscaleStats(optState_t* optPtr)
1238*a28cd43dSSascha Wildner {
1239*a28cd43dSSascha Wildner if (ZSTD_compressedLiterals(optPtr))
1240*a28cd43dSSascha Wildner optPtr->litSum = ZSTD_upscaleStat(optPtr->litFreq, MaxLit, 0);
1241*a28cd43dSSascha Wildner optPtr->litLengthSum = ZSTD_upscaleStat(optPtr->litLengthFreq, MaxLL, 0);
1242*a28cd43dSSascha Wildner optPtr->matchLengthSum = ZSTD_upscaleStat(optPtr->matchLengthFreq, MaxML, 0);
1243*a28cd43dSSascha Wildner optPtr->offCodeSum = ZSTD_upscaleStat(optPtr->offCodeFreq, MaxOff, 0);
1244*a28cd43dSSascha Wildner }
1245*a28cd43dSSascha Wildner
1246*a28cd43dSSascha Wildner /* ZSTD_initStats_ultra():
1247*a28cd43dSSascha Wildner * make a first compression pass, just to seed stats with more accurate starting values.
1248*a28cd43dSSascha Wildner * only works on first block, with no dictionary and no ldm.
1249*a28cd43dSSascha Wildner * this function cannot error, hence its contract must be respected.
1250*a28cd43dSSascha Wildner */
1251*a28cd43dSSascha Wildner static void
ZSTD_initStats_ultra(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],const void * src,size_t srcSize)1252*a28cd43dSSascha Wildner ZSTD_initStats_ultra(ZSTD_matchState_t* ms,
1253*a28cd43dSSascha Wildner seqStore_t* seqStore,
1254*a28cd43dSSascha Wildner U32 rep[ZSTD_REP_NUM],
1255*a28cd43dSSascha Wildner const void* src, size_t srcSize)
1256*a28cd43dSSascha Wildner {
1257*a28cd43dSSascha Wildner U32 tmpRep[ZSTD_REP_NUM]; /* updated rep codes will sink here */
1258*a28cd43dSSascha Wildner ZSTD_memcpy(tmpRep, rep, sizeof(tmpRep));
1259*a28cd43dSSascha Wildner
1260*a28cd43dSSascha Wildner DEBUGLOG(4, "ZSTD_initStats_ultra (srcSize=%zu)", srcSize);
1261*a28cd43dSSascha Wildner assert(ms->opt.litLengthSum == 0); /* first block */
1262*a28cd43dSSascha Wildner assert(seqStore->sequences == seqStore->sequencesStart); /* no ldm */
1263*a28cd43dSSascha Wildner assert(ms->window.dictLimit == ms->window.lowLimit); /* no dictionary */
1264*a28cd43dSSascha Wildner assert(ms->window.dictLimit - ms->nextToUpdate <= 1); /* no prefix (note: intentional overflow, defined as 2-complement) */
1265*a28cd43dSSascha Wildner
1266*a28cd43dSSascha Wildner ZSTD_compressBlock_opt_generic(ms, seqStore, tmpRep, src, srcSize, 2 /*optLevel*/, ZSTD_noDict); /* generate stats into ms->opt*/
1267*a28cd43dSSascha Wildner
1268*a28cd43dSSascha Wildner /* invalidate first scan from history */
1269*a28cd43dSSascha Wildner ZSTD_resetSeqStore(seqStore);
1270*a28cd43dSSascha Wildner ms->window.base -= srcSize;
1271*a28cd43dSSascha Wildner ms->window.dictLimit += (U32)srcSize;
1272*a28cd43dSSascha Wildner ms->window.lowLimit = ms->window.dictLimit;
1273*a28cd43dSSascha Wildner ms->nextToUpdate = ms->window.dictLimit;
1274*a28cd43dSSascha Wildner
1275*a28cd43dSSascha Wildner /* re-inforce weight of collected statistics */
1276*a28cd43dSSascha Wildner ZSTD_upscaleStats(&ms->opt);
1277*a28cd43dSSascha Wildner }
1278*a28cd43dSSascha Wildner
ZSTD_compressBlock_btultra(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],const void * src,size_t srcSize)1279*a28cd43dSSascha Wildner size_t ZSTD_compressBlock_btultra(
1280*a28cd43dSSascha Wildner ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
1281*a28cd43dSSascha Wildner const void* src, size_t srcSize)
1282*a28cd43dSSascha Wildner {
1283*a28cd43dSSascha Wildner DEBUGLOG(5, "ZSTD_compressBlock_btultra (srcSize=%zu)", srcSize);
1284*a28cd43dSSascha Wildner return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_noDict);
1285*a28cd43dSSascha Wildner }
1286*a28cd43dSSascha Wildner
ZSTD_compressBlock_btultra2(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],const void * src,size_t srcSize)1287*a28cd43dSSascha Wildner size_t ZSTD_compressBlock_btultra2(
1288*a28cd43dSSascha Wildner ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
1289*a28cd43dSSascha Wildner const void* src, size_t srcSize)
1290*a28cd43dSSascha Wildner {
1291*a28cd43dSSascha Wildner U32 const curr = (U32)((const BYTE*)src - ms->window.base);
1292*a28cd43dSSascha Wildner DEBUGLOG(5, "ZSTD_compressBlock_btultra2 (srcSize=%zu)", srcSize);
1293*a28cd43dSSascha Wildner
1294*a28cd43dSSascha Wildner /* 2-pass strategy:
1295*a28cd43dSSascha Wildner * this strategy makes a first pass over first block to collect statistics
1296*a28cd43dSSascha Wildner * and seed next round's statistics with it.
1297*a28cd43dSSascha Wildner * After 1st pass, function forgets everything, and starts a new block.
1298*a28cd43dSSascha Wildner * Consequently, this can only work if no data has been previously loaded in tables,
1299*a28cd43dSSascha Wildner * aka, no dictionary, no prefix, no ldm preprocessing.
1300*a28cd43dSSascha Wildner * The compression ratio gain is generally small (~0.5% on first block),
1301*a28cd43dSSascha Wildner * the cost is 2x cpu time on first block. */
1302*a28cd43dSSascha Wildner assert(srcSize <= ZSTD_BLOCKSIZE_MAX);
1303*a28cd43dSSascha Wildner if ( (ms->opt.litLengthSum==0) /* first block */
1304*a28cd43dSSascha Wildner && (seqStore->sequences == seqStore->sequencesStart) /* no ldm */
1305*a28cd43dSSascha Wildner && (ms->window.dictLimit == ms->window.lowLimit) /* no dictionary */
1306*a28cd43dSSascha Wildner && (curr == ms->window.dictLimit) /* start of frame, nothing already loaded nor skipped */
1307*a28cd43dSSascha Wildner && (srcSize > ZSTD_PREDEF_THRESHOLD)
1308*a28cd43dSSascha Wildner ) {
1309*a28cd43dSSascha Wildner ZSTD_initStats_ultra(ms, seqStore, rep, src, srcSize);
1310*a28cd43dSSascha Wildner }
1311*a28cd43dSSascha Wildner
1312*a28cd43dSSascha Wildner return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_noDict);
1313*a28cd43dSSascha Wildner }
1314*a28cd43dSSascha Wildner
ZSTD_compressBlock_btopt_dictMatchState(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],const void * src,size_t srcSize)1315*a28cd43dSSascha Wildner size_t ZSTD_compressBlock_btopt_dictMatchState(
1316*a28cd43dSSascha Wildner ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
1317*a28cd43dSSascha Wildner const void* src, size_t srcSize)
1318*a28cd43dSSascha Wildner {
1319*a28cd43dSSascha Wildner return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_dictMatchState);
1320*a28cd43dSSascha Wildner }
1321*a28cd43dSSascha Wildner
ZSTD_compressBlock_btultra_dictMatchState(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],const void * src,size_t srcSize)1322*a28cd43dSSascha Wildner size_t ZSTD_compressBlock_btultra_dictMatchState(
1323*a28cd43dSSascha Wildner ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
1324*a28cd43dSSascha Wildner const void* src, size_t srcSize)
1325*a28cd43dSSascha Wildner {
1326*a28cd43dSSascha Wildner return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_dictMatchState);
1327*a28cd43dSSascha Wildner }
1328*a28cd43dSSascha Wildner
ZSTD_compressBlock_btopt_extDict(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],const void * src,size_t srcSize)1329*a28cd43dSSascha Wildner size_t ZSTD_compressBlock_btopt_extDict(
1330*a28cd43dSSascha Wildner ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
1331*a28cd43dSSascha Wildner const void* src, size_t srcSize)
1332*a28cd43dSSascha Wildner {
1333*a28cd43dSSascha Wildner return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_extDict);
1334*a28cd43dSSascha Wildner }
1335*a28cd43dSSascha Wildner
ZSTD_compressBlock_btultra_extDict(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],const void * src,size_t srcSize)1336*a28cd43dSSascha Wildner size_t ZSTD_compressBlock_btultra_extDict(
1337*a28cd43dSSascha Wildner ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
1338*a28cd43dSSascha Wildner const void* src, size_t srcSize)
1339*a28cd43dSSascha Wildner {
1340*a28cd43dSSascha Wildner return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_extDict);
1341*a28cd43dSSascha Wildner }
1342*a28cd43dSSascha Wildner
1343*a28cd43dSSascha Wildner /* note : no btultra2 variant for extDict nor dictMatchState,
1344*a28cd43dSSascha Wildner * because btultra2 is not meant to work with dictionaries
1345*a28cd43dSSascha Wildner * and is only specific for the first block (no prefix) */
1346