1*a28cd43dSSascha Wildner /*
2*a28cd43dSSascha Wildner * Copyright (c) 2016-2020, 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" /* ZSTD_hashPtr, ZSTD_count, ZSTD_storeSeq */
12*a28cd43dSSascha Wildner #include "zstd_fast.h"
13*a28cd43dSSascha Wildner
14*a28cd43dSSascha Wildner
ZSTD_fillHashTable(ZSTD_matchState_t * ms,const void * const end,ZSTD_dictTableLoadMethod_e dtlm)15*a28cd43dSSascha Wildner void ZSTD_fillHashTable(ZSTD_matchState_t* ms,
16*a28cd43dSSascha Wildner const void* const end,
17*a28cd43dSSascha Wildner ZSTD_dictTableLoadMethod_e dtlm)
18*a28cd43dSSascha Wildner {
19*a28cd43dSSascha Wildner const ZSTD_compressionParameters* const cParams = &ms->cParams;
20*a28cd43dSSascha Wildner U32* const hashTable = ms->hashTable;
21*a28cd43dSSascha Wildner U32 const hBits = cParams->hashLog;
22*a28cd43dSSascha Wildner U32 const mls = cParams->minMatch;
23*a28cd43dSSascha Wildner const BYTE* const base = ms->window.base;
24*a28cd43dSSascha Wildner const BYTE* ip = base + ms->nextToUpdate;
25*a28cd43dSSascha Wildner const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
26*a28cd43dSSascha Wildner const U32 fastHashFillStep = 3;
27*a28cd43dSSascha Wildner
28*a28cd43dSSascha Wildner /* Always insert every fastHashFillStep position into the hash table.
29*a28cd43dSSascha Wildner * Insert the other positions if their hash entry is empty.
30*a28cd43dSSascha Wildner */
31*a28cd43dSSascha Wildner for ( ; ip + fastHashFillStep < iend + 2; ip += fastHashFillStep) {
32*a28cd43dSSascha Wildner U32 const curr = (U32)(ip - base);
33*a28cd43dSSascha Wildner size_t const hash0 = ZSTD_hashPtr(ip, hBits, mls);
34*a28cd43dSSascha Wildner hashTable[hash0] = curr;
35*a28cd43dSSascha Wildner if (dtlm == ZSTD_dtlm_fast) continue;
36*a28cd43dSSascha Wildner /* Only load extra positions for ZSTD_dtlm_full */
37*a28cd43dSSascha Wildner { U32 p;
38*a28cd43dSSascha Wildner for (p = 1; p < fastHashFillStep; ++p) {
39*a28cd43dSSascha Wildner size_t const hash = ZSTD_hashPtr(ip + p, hBits, mls);
40*a28cd43dSSascha Wildner if (hashTable[hash] == 0) { /* not yet filled */
41*a28cd43dSSascha Wildner hashTable[hash] = curr + p;
42*a28cd43dSSascha Wildner } } } }
43*a28cd43dSSascha Wildner }
44*a28cd43dSSascha Wildner
45*a28cd43dSSascha Wildner
46*a28cd43dSSascha Wildner FORCE_INLINE_TEMPLATE size_t
ZSTD_compressBlock_fast_generic(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],void const * src,size_t srcSize,U32 const mls)47*a28cd43dSSascha Wildner ZSTD_compressBlock_fast_generic(
48*a28cd43dSSascha Wildner ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
49*a28cd43dSSascha Wildner void const* src, size_t srcSize,
50*a28cd43dSSascha Wildner U32 const mls)
51*a28cd43dSSascha Wildner {
52*a28cd43dSSascha Wildner const ZSTD_compressionParameters* const cParams = &ms->cParams;
53*a28cd43dSSascha Wildner U32* const hashTable = ms->hashTable;
54*a28cd43dSSascha Wildner U32 const hlog = cParams->hashLog;
55*a28cd43dSSascha Wildner /* support stepSize of 0 */
56*a28cd43dSSascha Wildner size_t const stepSize = cParams->targetLength + !(cParams->targetLength) + 1;
57*a28cd43dSSascha Wildner const BYTE* const base = ms->window.base;
58*a28cd43dSSascha Wildner const BYTE* const istart = (const BYTE*)src;
59*a28cd43dSSascha Wildner /* We check ip0 (ip + 0) and ip1 (ip + 1) each loop */
60*a28cd43dSSascha Wildner const BYTE* ip0 = istart;
61*a28cd43dSSascha Wildner const BYTE* ip1;
62*a28cd43dSSascha Wildner const BYTE* anchor = istart;
63*a28cd43dSSascha Wildner const U32 endIndex = (U32)((size_t)(istart - base) + srcSize);
64*a28cd43dSSascha Wildner const U32 prefixStartIndex = ZSTD_getLowestPrefixIndex(ms, endIndex, cParams->windowLog);
65*a28cd43dSSascha Wildner const BYTE* const prefixStart = base + prefixStartIndex;
66*a28cd43dSSascha Wildner const BYTE* const iend = istart + srcSize;
67*a28cd43dSSascha Wildner const BYTE* const ilimit = iend - HASH_READ_SIZE;
68*a28cd43dSSascha Wildner U32 offset_1=rep[0], offset_2=rep[1];
69*a28cd43dSSascha Wildner U32 offsetSaved = 0;
70*a28cd43dSSascha Wildner
71*a28cd43dSSascha Wildner /* init */
72*a28cd43dSSascha Wildner DEBUGLOG(5, "ZSTD_compressBlock_fast_generic");
73*a28cd43dSSascha Wildner ip0 += (ip0 == prefixStart);
74*a28cd43dSSascha Wildner ip1 = ip0 + 1;
75*a28cd43dSSascha Wildner { U32 const curr = (U32)(ip0 - base);
76*a28cd43dSSascha Wildner U32 const windowLow = ZSTD_getLowestPrefixIndex(ms, curr, cParams->windowLog);
77*a28cd43dSSascha Wildner U32 const maxRep = curr - windowLow;
78*a28cd43dSSascha Wildner if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0;
79*a28cd43dSSascha Wildner if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0;
80*a28cd43dSSascha Wildner }
81*a28cd43dSSascha Wildner
82*a28cd43dSSascha Wildner /* Main Search Loop */
83*a28cd43dSSascha Wildner #ifdef __INTEL_COMPILER
84*a28cd43dSSascha Wildner /* From intel 'The vector pragma indicates that the loop should be
85*a28cd43dSSascha Wildner * vectorized if it is legal to do so'. Can be used together with
86*a28cd43dSSascha Wildner * #pragma ivdep (but have opted to exclude that because intel
87*a28cd43dSSascha Wildner * warns against using it).*/
88*a28cd43dSSascha Wildner #pragma vector always
89*a28cd43dSSascha Wildner #endif
90*a28cd43dSSascha Wildner while (ip1 < ilimit) { /* < instead of <=, because check at ip0+2 */
91*a28cd43dSSascha Wildner size_t mLength;
92*a28cd43dSSascha Wildner BYTE const* ip2 = ip0 + 2;
93*a28cd43dSSascha Wildner size_t const h0 = ZSTD_hashPtr(ip0, hlog, mls);
94*a28cd43dSSascha Wildner U32 const val0 = MEM_read32(ip0);
95*a28cd43dSSascha Wildner size_t const h1 = ZSTD_hashPtr(ip1, hlog, mls);
96*a28cd43dSSascha Wildner U32 const val1 = MEM_read32(ip1);
97*a28cd43dSSascha Wildner U32 const current0 = (U32)(ip0-base);
98*a28cd43dSSascha Wildner U32 const current1 = (U32)(ip1-base);
99*a28cd43dSSascha Wildner U32 const matchIndex0 = hashTable[h0];
100*a28cd43dSSascha Wildner U32 const matchIndex1 = hashTable[h1];
101*a28cd43dSSascha Wildner BYTE const* repMatch = ip2 - offset_1;
102*a28cd43dSSascha Wildner const BYTE* match0 = base + matchIndex0;
103*a28cd43dSSascha Wildner const BYTE* match1 = base + matchIndex1;
104*a28cd43dSSascha Wildner U32 offcode;
105*a28cd43dSSascha Wildner
106*a28cd43dSSascha Wildner #if defined(__aarch64__)
107*a28cd43dSSascha Wildner PREFETCH_L1(ip0+256);
108*a28cd43dSSascha Wildner #endif
109*a28cd43dSSascha Wildner
110*a28cd43dSSascha Wildner hashTable[h0] = current0; /* update hash table */
111*a28cd43dSSascha Wildner hashTable[h1] = current1; /* update hash table */
112*a28cd43dSSascha Wildner
113*a28cd43dSSascha Wildner assert(ip0 + 1 == ip1);
114*a28cd43dSSascha Wildner
115*a28cd43dSSascha Wildner if ((offset_1 > 0) & (MEM_read32(repMatch) == MEM_read32(ip2))) {
116*a28cd43dSSascha Wildner mLength = (ip2[-1] == repMatch[-1]) ? 1 : 0;
117*a28cd43dSSascha Wildner ip0 = ip2 - mLength;
118*a28cd43dSSascha Wildner match0 = repMatch - mLength;
119*a28cd43dSSascha Wildner mLength += 4;
120*a28cd43dSSascha Wildner offcode = 0;
121*a28cd43dSSascha Wildner goto _match;
122*a28cd43dSSascha Wildner }
123*a28cd43dSSascha Wildner if ((matchIndex0 > prefixStartIndex) && MEM_read32(match0) == val0) {
124*a28cd43dSSascha Wildner /* found a regular match */
125*a28cd43dSSascha Wildner goto _offset;
126*a28cd43dSSascha Wildner }
127*a28cd43dSSascha Wildner if ((matchIndex1 > prefixStartIndex) && MEM_read32(match1) == val1) {
128*a28cd43dSSascha Wildner /* found a regular match after one literal */
129*a28cd43dSSascha Wildner ip0 = ip1;
130*a28cd43dSSascha Wildner match0 = match1;
131*a28cd43dSSascha Wildner goto _offset;
132*a28cd43dSSascha Wildner }
133*a28cd43dSSascha Wildner { size_t const step = ((size_t)(ip0-anchor) >> (kSearchStrength - 1)) + stepSize;
134*a28cd43dSSascha Wildner assert(step >= 2);
135*a28cd43dSSascha Wildner ip0 += step;
136*a28cd43dSSascha Wildner ip1 += step;
137*a28cd43dSSascha Wildner continue;
138*a28cd43dSSascha Wildner }
139*a28cd43dSSascha Wildner _offset: /* Requires: ip0, match0 */
140*a28cd43dSSascha Wildner /* Compute the offset code */
141*a28cd43dSSascha Wildner offset_2 = offset_1;
142*a28cd43dSSascha Wildner offset_1 = (U32)(ip0-match0);
143*a28cd43dSSascha Wildner offcode = offset_1 + ZSTD_REP_MOVE;
144*a28cd43dSSascha Wildner mLength = 4;
145*a28cd43dSSascha Wildner /* Count the backwards match length */
146*a28cd43dSSascha Wildner while (((ip0>anchor) & (match0>prefixStart))
147*a28cd43dSSascha Wildner && (ip0[-1] == match0[-1])) { ip0--; match0--; mLength++; } /* catch up */
148*a28cd43dSSascha Wildner
149*a28cd43dSSascha Wildner _match: /* Requires: ip0, match0, offcode */
150*a28cd43dSSascha Wildner /* Count the forward length */
151*a28cd43dSSascha Wildner mLength += ZSTD_count(ip0+mLength, match0+mLength, iend);
152*a28cd43dSSascha Wildner ZSTD_storeSeq(seqStore, (size_t)(ip0-anchor), anchor, iend, offcode, mLength-MINMATCH);
153*a28cd43dSSascha Wildner /* match found */
154*a28cd43dSSascha Wildner ip0 += mLength;
155*a28cd43dSSascha Wildner anchor = ip0;
156*a28cd43dSSascha Wildner
157*a28cd43dSSascha Wildner if (ip0 <= ilimit) {
158*a28cd43dSSascha Wildner /* Fill Table */
159*a28cd43dSSascha Wildner assert(base+current0+2 > istart); /* check base overflow */
160*a28cd43dSSascha Wildner hashTable[ZSTD_hashPtr(base+current0+2, hlog, mls)] = current0+2; /* here because current+2 could be > iend-8 */
161*a28cd43dSSascha Wildner hashTable[ZSTD_hashPtr(ip0-2, hlog, mls)] = (U32)(ip0-2-base);
162*a28cd43dSSascha Wildner
163*a28cd43dSSascha Wildner if (offset_2 > 0) { /* offset_2==0 means offset_2 is invalidated */
164*a28cd43dSSascha Wildner while ( (ip0 <= ilimit) && (MEM_read32(ip0) == MEM_read32(ip0 - offset_2)) ) {
165*a28cd43dSSascha Wildner /* store sequence */
166*a28cd43dSSascha Wildner size_t const rLength = ZSTD_count(ip0+4, ip0+4-offset_2, iend) + 4;
167*a28cd43dSSascha Wildner { U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff; } /* swap offset_2 <=> offset_1 */
168*a28cd43dSSascha Wildner hashTable[ZSTD_hashPtr(ip0, hlog, mls)] = (U32)(ip0-base);
169*a28cd43dSSascha Wildner ip0 += rLength;
170*a28cd43dSSascha Wildner ZSTD_storeSeq(seqStore, 0 /*litLen*/, anchor, iend, 0 /*offCode*/, rLength-MINMATCH);
171*a28cd43dSSascha Wildner anchor = ip0;
172*a28cd43dSSascha Wildner continue; /* faster when present (confirmed on gcc-8) ... (?) */
173*a28cd43dSSascha Wildner } } }
174*a28cd43dSSascha Wildner ip1 = ip0 + 1;
175*a28cd43dSSascha Wildner }
176*a28cd43dSSascha Wildner
177*a28cd43dSSascha Wildner /* save reps for next block */
178*a28cd43dSSascha Wildner rep[0] = offset_1 ? offset_1 : offsetSaved;
179*a28cd43dSSascha Wildner rep[1] = offset_2 ? offset_2 : offsetSaved;
180*a28cd43dSSascha Wildner
181*a28cd43dSSascha Wildner /* Return the last literals size */
182*a28cd43dSSascha Wildner return (size_t)(iend - anchor);
183*a28cd43dSSascha Wildner }
184*a28cd43dSSascha Wildner
185*a28cd43dSSascha Wildner
ZSTD_compressBlock_fast(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],void const * src,size_t srcSize)186*a28cd43dSSascha Wildner size_t ZSTD_compressBlock_fast(
187*a28cd43dSSascha Wildner ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
188*a28cd43dSSascha Wildner void const* src, size_t srcSize)
189*a28cd43dSSascha Wildner {
190*a28cd43dSSascha Wildner U32 const mls = ms->cParams.minMatch;
191*a28cd43dSSascha Wildner assert(ms->dictMatchState == NULL);
192*a28cd43dSSascha Wildner switch(mls)
193*a28cd43dSSascha Wildner {
194*a28cd43dSSascha Wildner default: /* includes case 3 */
195*a28cd43dSSascha Wildner case 4 :
196*a28cd43dSSascha Wildner return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 4);
197*a28cd43dSSascha Wildner case 5 :
198*a28cd43dSSascha Wildner return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 5);
199*a28cd43dSSascha Wildner case 6 :
200*a28cd43dSSascha Wildner return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 6);
201*a28cd43dSSascha Wildner case 7 :
202*a28cd43dSSascha Wildner return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 7);
203*a28cd43dSSascha Wildner }
204*a28cd43dSSascha Wildner }
205*a28cd43dSSascha Wildner
206*a28cd43dSSascha Wildner FORCE_INLINE_TEMPLATE
ZSTD_compressBlock_fast_dictMatchState_generic(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],void const * src,size_t srcSize,U32 const mls)207*a28cd43dSSascha Wildner size_t ZSTD_compressBlock_fast_dictMatchState_generic(
208*a28cd43dSSascha Wildner ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
209*a28cd43dSSascha Wildner void const* src, size_t srcSize, U32 const mls)
210*a28cd43dSSascha Wildner {
211*a28cd43dSSascha Wildner const ZSTD_compressionParameters* const cParams = &ms->cParams;
212*a28cd43dSSascha Wildner U32* const hashTable = ms->hashTable;
213*a28cd43dSSascha Wildner U32 const hlog = cParams->hashLog;
214*a28cd43dSSascha Wildner /* support stepSize of 0 */
215*a28cd43dSSascha Wildner U32 const stepSize = cParams->targetLength + !(cParams->targetLength);
216*a28cd43dSSascha Wildner const BYTE* const base = ms->window.base;
217*a28cd43dSSascha Wildner const BYTE* const istart = (const BYTE*)src;
218*a28cd43dSSascha Wildner const BYTE* ip = istart;
219*a28cd43dSSascha Wildner const BYTE* anchor = istart;
220*a28cd43dSSascha Wildner const U32 prefixStartIndex = ms->window.dictLimit;
221*a28cd43dSSascha Wildner const BYTE* const prefixStart = base + prefixStartIndex;
222*a28cd43dSSascha Wildner const BYTE* const iend = istart + srcSize;
223*a28cd43dSSascha Wildner const BYTE* const ilimit = iend - HASH_READ_SIZE;
224*a28cd43dSSascha Wildner U32 offset_1=rep[0], offset_2=rep[1];
225*a28cd43dSSascha Wildner U32 offsetSaved = 0;
226*a28cd43dSSascha Wildner
227*a28cd43dSSascha Wildner const ZSTD_matchState_t* const dms = ms->dictMatchState;
228*a28cd43dSSascha Wildner const ZSTD_compressionParameters* const dictCParams = &dms->cParams ;
229*a28cd43dSSascha Wildner const U32* const dictHashTable = dms->hashTable;
230*a28cd43dSSascha Wildner const U32 dictStartIndex = dms->window.dictLimit;
231*a28cd43dSSascha Wildner const BYTE* const dictBase = dms->window.base;
232*a28cd43dSSascha Wildner const BYTE* const dictStart = dictBase + dictStartIndex;
233*a28cd43dSSascha Wildner const BYTE* const dictEnd = dms->window.nextSrc;
234*a28cd43dSSascha Wildner const U32 dictIndexDelta = prefixStartIndex - (U32)(dictEnd - dictBase);
235*a28cd43dSSascha Wildner const U32 dictAndPrefixLength = (U32)(ip - prefixStart + dictEnd - dictStart);
236*a28cd43dSSascha Wildner const U32 dictHLog = dictCParams->hashLog;
237*a28cd43dSSascha Wildner
238*a28cd43dSSascha Wildner /* if a dictionary is still attached, it necessarily means that
239*a28cd43dSSascha Wildner * it is within window size. So we just check it. */
240*a28cd43dSSascha Wildner const U32 maxDistance = 1U << cParams->windowLog;
241*a28cd43dSSascha Wildner const U32 endIndex = (U32)((size_t)(ip - base) + srcSize);
242*a28cd43dSSascha Wildner assert(endIndex - prefixStartIndex <= maxDistance);
243*a28cd43dSSascha Wildner (void)maxDistance; (void)endIndex; /* these variables are not used when assert() is disabled */
244*a28cd43dSSascha Wildner
245*a28cd43dSSascha Wildner /* ensure there will be no no underflow
246*a28cd43dSSascha Wildner * when translating a dict index into a local index */
247*a28cd43dSSascha Wildner assert(prefixStartIndex >= (U32)(dictEnd - dictBase));
248*a28cd43dSSascha Wildner
249*a28cd43dSSascha Wildner /* init */
250*a28cd43dSSascha Wildner DEBUGLOG(5, "ZSTD_compressBlock_fast_dictMatchState_generic");
251*a28cd43dSSascha Wildner ip += (dictAndPrefixLength == 0);
252*a28cd43dSSascha Wildner /* dictMatchState repCode checks don't currently handle repCode == 0
253*a28cd43dSSascha Wildner * disabling. */
254*a28cd43dSSascha Wildner assert(offset_1 <= dictAndPrefixLength);
255*a28cd43dSSascha Wildner assert(offset_2 <= dictAndPrefixLength);
256*a28cd43dSSascha Wildner
257*a28cd43dSSascha Wildner /* Main Search Loop */
258*a28cd43dSSascha Wildner while (ip < ilimit) { /* < instead of <=, because repcode check at (ip+1) */
259*a28cd43dSSascha Wildner size_t mLength;
260*a28cd43dSSascha Wildner size_t const h = ZSTD_hashPtr(ip, hlog, mls);
261*a28cd43dSSascha Wildner U32 const curr = (U32)(ip-base);
262*a28cd43dSSascha Wildner U32 const matchIndex = hashTable[h];
263*a28cd43dSSascha Wildner const BYTE* match = base + matchIndex;
264*a28cd43dSSascha Wildner const U32 repIndex = curr + 1 - offset_1;
265*a28cd43dSSascha Wildner const BYTE* repMatch = (repIndex < prefixStartIndex) ?
266*a28cd43dSSascha Wildner dictBase + (repIndex - dictIndexDelta) :
267*a28cd43dSSascha Wildner base + repIndex;
268*a28cd43dSSascha Wildner hashTable[h] = curr; /* update hash table */
269*a28cd43dSSascha Wildner
270*a28cd43dSSascha Wildner if ( ((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow : ensure repIndex isn't overlapping dict + prefix */
271*a28cd43dSSascha Wildner && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
272*a28cd43dSSascha Wildner const BYTE* const repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
273*a28cd43dSSascha Wildner mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixStart) + 4;
274*a28cd43dSSascha Wildner ip++;
275*a28cd43dSSascha Wildner ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, 0, mLength-MINMATCH);
276*a28cd43dSSascha Wildner } else if ( (matchIndex <= prefixStartIndex) ) {
277*a28cd43dSSascha Wildner size_t const dictHash = ZSTD_hashPtr(ip, dictHLog, mls);
278*a28cd43dSSascha Wildner U32 const dictMatchIndex = dictHashTable[dictHash];
279*a28cd43dSSascha Wildner const BYTE* dictMatch = dictBase + dictMatchIndex;
280*a28cd43dSSascha Wildner if (dictMatchIndex <= dictStartIndex ||
281*a28cd43dSSascha Wildner MEM_read32(dictMatch) != MEM_read32(ip)) {
282*a28cd43dSSascha Wildner assert(stepSize >= 1);
283*a28cd43dSSascha Wildner ip += ((ip-anchor) >> kSearchStrength) + stepSize;
284*a28cd43dSSascha Wildner continue;
285*a28cd43dSSascha Wildner } else {
286*a28cd43dSSascha Wildner /* found a dict match */
287*a28cd43dSSascha Wildner U32 const offset = (U32)(curr-dictMatchIndex-dictIndexDelta);
288*a28cd43dSSascha Wildner mLength = ZSTD_count_2segments(ip+4, dictMatch+4, iend, dictEnd, prefixStart) + 4;
289*a28cd43dSSascha Wildner while (((ip>anchor) & (dictMatch>dictStart))
290*a28cd43dSSascha Wildner && (ip[-1] == dictMatch[-1])) {
291*a28cd43dSSascha Wildner ip--; dictMatch--; mLength++;
292*a28cd43dSSascha Wildner } /* catch up */
293*a28cd43dSSascha Wildner offset_2 = offset_1;
294*a28cd43dSSascha Wildner offset_1 = offset;
295*a28cd43dSSascha Wildner ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
296*a28cd43dSSascha Wildner }
297*a28cd43dSSascha Wildner } else if (MEM_read32(match) != MEM_read32(ip)) {
298*a28cd43dSSascha Wildner /* it's not a match, and we're not going to check the dictionary */
299*a28cd43dSSascha Wildner assert(stepSize >= 1);
300*a28cd43dSSascha Wildner ip += ((ip-anchor) >> kSearchStrength) + stepSize;
301*a28cd43dSSascha Wildner continue;
302*a28cd43dSSascha Wildner } else {
303*a28cd43dSSascha Wildner /* found a regular match */
304*a28cd43dSSascha Wildner U32 const offset = (U32)(ip-match);
305*a28cd43dSSascha Wildner mLength = ZSTD_count(ip+4, match+4, iend) + 4;
306*a28cd43dSSascha Wildner while (((ip>anchor) & (match>prefixStart))
307*a28cd43dSSascha Wildner && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
308*a28cd43dSSascha Wildner offset_2 = offset_1;
309*a28cd43dSSascha Wildner offset_1 = offset;
310*a28cd43dSSascha Wildner ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
311*a28cd43dSSascha Wildner }
312*a28cd43dSSascha Wildner
313*a28cd43dSSascha Wildner /* match found */
314*a28cd43dSSascha Wildner ip += mLength;
315*a28cd43dSSascha Wildner anchor = ip;
316*a28cd43dSSascha Wildner
317*a28cd43dSSascha Wildner if (ip <= ilimit) {
318*a28cd43dSSascha Wildner /* Fill Table */
319*a28cd43dSSascha Wildner assert(base+curr+2 > istart); /* check base overflow */
320*a28cd43dSSascha Wildner hashTable[ZSTD_hashPtr(base+curr+2, hlog, mls)] = curr+2; /* here because curr+2 could be > iend-8 */
321*a28cd43dSSascha Wildner hashTable[ZSTD_hashPtr(ip-2, hlog, mls)] = (U32)(ip-2-base);
322*a28cd43dSSascha Wildner
323*a28cd43dSSascha Wildner /* check immediate repcode */
324*a28cd43dSSascha Wildner while (ip <= ilimit) {
325*a28cd43dSSascha Wildner U32 const current2 = (U32)(ip-base);
326*a28cd43dSSascha Wildner U32 const repIndex2 = current2 - offset_2;
327*a28cd43dSSascha Wildner const BYTE* repMatch2 = repIndex2 < prefixStartIndex ?
328*a28cd43dSSascha Wildner dictBase - dictIndexDelta + repIndex2 :
329*a28cd43dSSascha Wildner base + repIndex2;
330*a28cd43dSSascha Wildner if ( ((U32)((prefixStartIndex-1) - (U32)repIndex2) >= 3 /* intentional overflow */)
331*a28cd43dSSascha Wildner && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
332*a28cd43dSSascha Wildner const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend;
333*a28cd43dSSascha Wildner size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixStart) + 4;
334*a28cd43dSSascha Wildner U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset; /* swap offset_2 <=> offset_1 */
335*a28cd43dSSascha Wildner ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, repLength2-MINMATCH);
336*a28cd43dSSascha Wildner hashTable[ZSTD_hashPtr(ip, hlog, mls)] = current2;
337*a28cd43dSSascha Wildner ip += repLength2;
338*a28cd43dSSascha Wildner anchor = ip;
339*a28cd43dSSascha Wildner continue;
340*a28cd43dSSascha Wildner }
341*a28cd43dSSascha Wildner break;
342*a28cd43dSSascha Wildner }
343*a28cd43dSSascha Wildner }
344*a28cd43dSSascha Wildner }
345*a28cd43dSSascha Wildner
346*a28cd43dSSascha Wildner /* save reps for next block */
347*a28cd43dSSascha Wildner rep[0] = offset_1 ? offset_1 : offsetSaved;
348*a28cd43dSSascha Wildner rep[1] = offset_2 ? offset_2 : offsetSaved;
349*a28cd43dSSascha Wildner
350*a28cd43dSSascha Wildner /* Return the last literals size */
351*a28cd43dSSascha Wildner return (size_t)(iend - anchor);
352*a28cd43dSSascha Wildner }
353*a28cd43dSSascha Wildner
ZSTD_compressBlock_fast_dictMatchState(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],void const * src,size_t srcSize)354*a28cd43dSSascha Wildner size_t ZSTD_compressBlock_fast_dictMatchState(
355*a28cd43dSSascha Wildner ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
356*a28cd43dSSascha Wildner void const* src, size_t srcSize)
357*a28cd43dSSascha Wildner {
358*a28cd43dSSascha Wildner U32 const mls = ms->cParams.minMatch;
359*a28cd43dSSascha Wildner assert(ms->dictMatchState != NULL);
360*a28cd43dSSascha Wildner switch(mls)
361*a28cd43dSSascha Wildner {
362*a28cd43dSSascha Wildner default: /* includes case 3 */
363*a28cd43dSSascha Wildner case 4 :
364*a28cd43dSSascha Wildner return ZSTD_compressBlock_fast_dictMatchState_generic(ms, seqStore, rep, src, srcSize, 4);
365*a28cd43dSSascha Wildner case 5 :
366*a28cd43dSSascha Wildner return ZSTD_compressBlock_fast_dictMatchState_generic(ms, seqStore, rep, src, srcSize, 5);
367*a28cd43dSSascha Wildner case 6 :
368*a28cd43dSSascha Wildner return ZSTD_compressBlock_fast_dictMatchState_generic(ms, seqStore, rep, src, srcSize, 6);
369*a28cd43dSSascha Wildner case 7 :
370*a28cd43dSSascha Wildner return ZSTD_compressBlock_fast_dictMatchState_generic(ms, seqStore, rep, src, srcSize, 7);
371*a28cd43dSSascha Wildner }
372*a28cd43dSSascha Wildner }
373*a28cd43dSSascha Wildner
374*a28cd43dSSascha Wildner
ZSTD_compressBlock_fast_extDict_generic(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],void const * src,size_t srcSize,U32 const mls)375*a28cd43dSSascha Wildner static size_t ZSTD_compressBlock_fast_extDict_generic(
376*a28cd43dSSascha Wildner ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
377*a28cd43dSSascha Wildner void const* src, size_t srcSize, U32 const mls)
378*a28cd43dSSascha Wildner {
379*a28cd43dSSascha Wildner const ZSTD_compressionParameters* const cParams = &ms->cParams;
380*a28cd43dSSascha Wildner U32* const hashTable = ms->hashTable;
381*a28cd43dSSascha Wildner U32 const hlog = cParams->hashLog;
382*a28cd43dSSascha Wildner /* support stepSize of 0 */
383*a28cd43dSSascha Wildner U32 const stepSize = cParams->targetLength + !(cParams->targetLength);
384*a28cd43dSSascha Wildner const BYTE* const base = ms->window.base;
385*a28cd43dSSascha Wildner const BYTE* const dictBase = ms->window.dictBase;
386*a28cd43dSSascha Wildner const BYTE* const istart = (const BYTE*)src;
387*a28cd43dSSascha Wildner const BYTE* ip = istart;
388*a28cd43dSSascha Wildner const BYTE* anchor = istart;
389*a28cd43dSSascha Wildner const U32 endIndex = (U32)((size_t)(istart - base) + srcSize);
390*a28cd43dSSascha Wildner const U32 lowLimit = ZSTD_getLowestMatchIndex(ms, endIndex, cParams->windowLog);
391*a28cd43dSSascha Wildner const U32 dictStartIndex = lowLimit;
392*a28cd43dSSascha Wildner const BYTE* const dictStart = dictBase + dictStartIndex;
393*a28cd43dSSascha Wildner const U32 dictLimit = ms->window.dictLimit;
394*a28cd43dSSascha Wildner const U32 prefixStartIndex = dictLimit < lowLimit ? lowLimit : dictLimit;
395*a28cd43dSSascha Wildner const BYTE* const prefixStart = base + prefixStartIndex;
396*a28cd43dSSascha Wildner const BYTE* const dictEnd = dictBase + prefixStartIndex;
397*a28cd43dSSascha Wildner const BYTE* const iend = istart + srcSize;
398*a28cd43dSSascha Wildner const BYTE* const ilimit = iend - 8;
399*a28cd43dSSascha Wildner U32 offset_1=rep[0], offset_2=rep[1];
400*a28cd43dSSascha Wildner
401*a28cd43dSSascha Wildner DEBUGLOG(5, "ZSTD_compressBlock_fast_extDict_generic (offset_1=%u)", offset_1);
402*a28cd43dSSascha Wildner
403*a28cd43dSSascha Wildner /* switch to "regular" variant if extDict is invalidated due to maxDistance */
404*a28cd43dSSascha Wildner if (prefixStartIndex == dictStartIndex)
405*a28cd43dSSascha Wildner return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, mls);
406*a28cd43dSSascha Wildner
407*a28cd43dSSascha Wildner /* Search Loop */
408*a28cd43dSSascha Wildner while (ip < ilimit) { /* < instead of <=, because (ip+1) */
409*a28cd43dSSascha Wildner const size_t h = ZSTD_hashPtr(ip, hlog, mls);
410*a28cd43dSSascha Wildner const U32 matchIndex = hashTable[h];
411*a28cd43dSSascha Wildner const BYTE* const matchBase = matchIndex < prefixStartIndex ? dictBase : base;
412*a28cd43dSSascha Wildner const BYTE* match = matchBase + matchIndex;
413*a28cd43dSSascha Wildner const U32 curr = (U32)(ip-base);
414*a28cd43dSSascha Wildner const U32 repIndex = curr + 1 - offset_1;
415*a28cd43dSSascha Wildner const BYTE* const repBase = repIndex < prefixStartIndex ? dictBase : base;
416*a28cd43dSSascha Wildner const BYTE* const repMatch = repBase + repIndex;
417*a28cd43dSSascha Wildner hashTable[h] = curr; /* update hash table */
418*a28cd43dSSascha Wildner DEBUGLOG(7, "offset_1 = %u , curr = %u", offset_1, curr);
419*a28cd43dSSascha Wildner assert(offset_1 <= curr +1); /* check repIndex */
420*a28cd43dSSascha Wildner
421*a28cd43dSSascha Wildner if ( (((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow */ & (repIndex > dictStartIndex))
422*a28cd43dSSascha Wildner && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
423*a28cd43dSSascha Wildner const BYTE* const repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
424*a28cd43dSSascha Wildner size_t const rLength = ZSTD_count_2segments(ip+1 +4, repMatch +4, iend, repMatchEnd, prefixStart) + 4;
425*a28cd43dSSascha Wildner ip++;
426*a28cd43dSSascha Wildner ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, 0, rLength-MINMATCH);
427*a28cd43dSSascha Wildner ip += rLength;
428*a28cd43dSSascha Wildner anchor = ip;
429*a28cd43dSSascha Wildner } else {
430*a28cd43dSSascha Wildner if ( (matchIndex < dictStartIndex) ||
431*a28cd43dSSascha Wildner (MEM_read32(match) != MEM_read32(ip)) ) {
432*a28cd43dSSascha Wildner assert(stepSize >= 1);
433*a28cd43dSSascha Wildner ip += ((ip-anchor) >> kSearchStrength) + stepSize;
434*a28cd43dSSascha Wildner continue;
435*a28cd43dSSascha Wildner }
436*a28cd43dSSascha Wildner { const BYTE* const matchEnd = matchIndex < prefixStartIndex ? dictEnd : iend;
437*a28cd43dSSascha Wildner const BYTE* const lowMatchPtr = matchIndex < prefixStartIndex ? dictStart : prefixStart;
438*a28cd43dSSascha Wildner U32 const offset = curr - matchIndex;
439*a28cd43dSSascha Wildner size_t mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, prefixStart) + 4;
440*a28cd43dSSascha Wildner while (((ip>anchor) & (match>lowMatchPtr)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
441*a28cd43dSSascha Wildner offset_2 = offset_1; offset_1 = offset; /* update offset history */
442*a28cd43dSSascha Wildner ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
443*a28cd43dSSascha Wildner ip += mLength;
444*a28cd43dSSascha Wildner anchor = ip;
445*a28cd43dSSascha Wildner } }
446*a28cd43dSSascha Wildner
447*a28cd43dSSascha Wildner if (ip <= ilimit) {
448*a28cd43dSSascha Wildner /* Fill Table */
449*a28cd43dSSascha Wildner hashTable[ZSTD_hashPtr(base+curr+2, hlog, mls)] = curr+2;
450*a28cd43dSSascha Wildner hashTable[ZSTD_hashPtr(ip-2, hlog, mls)] = (U32)(ip-2-base);
451*a28cd43dSSascha Wildner /* check immediate repcode */
452*a28cd43dSSascha Wildner while (ip <= ilimit) {
453*a28cd43dSSascha Wildner U32 const current2 = (U32)(ip-base);
454*a28cd43dSSascha Wildner U32 const repIndex2 = current2 - offset_2;
455*a28cd43dSSascha Wildner const BYTE* const repMatch2 = repIndex2 < prefixStartIndex ? dictBase + repIndex2 : base + repIndex2;
456*a28cd43dSSascha Wildner if ( (((U32)((prefixStartIndex-1) - repIndex2) >= 3) & (repIndex2 > dictStartIndex)) /* intentional overflow */
457*a28cd43dSSascha Wildner && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
458*a28cd43dSSascha Wildner const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend;
459*a28cd43dSSascha Wildner size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixStart) + 4;
460*a28cd43dSSascha Wildner { U32 const tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset; } /* swap offset_2 <=> offset_1 */
461*a28cd43dSSascha Wildner ZSTD_storeSeq(seqStore, 0 /*litlen*/, anchor, iend, 0 /*offcode*/, repLength2-MINMATCH);
462*a28cd43dSSascha Wildner hashTable[ZSTD_hashPtr(ip, hlog, mls)] = current2;
463*a28cd43dSSascha Wildner ip += repLength2;
464*a28cd43dSSascha Wildner anchor = ip;
465*a28cd43dSSascha Wildner continue;
466*a28cd43dSSascha Wildner }
467*a28cd43dSSascha Wildner break;
468*a28cd43dSSascha Wildner } } }
469*a28cd43dSSascha Wildner
470*a28cd43dSSascha Wildner /* save reps for next block */
471*a28cd43dSSascha Wildner rep[0] = offset_1;
472*a28cd43dSSascha Wildner rep[1] = offset_2;
473*a28cd43dSSascha Wildner
474*a28cd43dSSascha Wildner /* Return the last literals size */
475*a28cd43dSSascha Wildner return (size_t)(iend - anchor);
476*a28cd43dSSascha Wildner }
477*a28cd43dSSascha Wildner
478*a28cd43dSSascha Wildner
ZSTD_compressBlock_fast_extDict(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],void const * src,size_t srcSize)479*a28cd43dSSascha Wildner size_t ZSTD_compressBlock_fast_extDict(
480*a28cd43dSSascha Wildner ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
481*a28cd43dSSascha Wildner void const* src, size_t srcSize)
482*a28cd43dSSascha Wildner {
483*a28cd43dSSascha Wildner U32 const mls = ms->cParams.minMatch;
484*a28cd43dSSascha Wildner switch(mls)
485*a28cd43dSSascha Wildner {
486*a28cd43dSSascha Wildner default: /* includes case 3 */
487*a28cd43dSSascha Wildner case 4 :
488*a28cd43dSSascha Wildner return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, 4);
489*a28cd43dSSascha Wildner case 5 :
490*a28cd43dSSascha Wildner return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, 5);
491*a28cd43dSSascha Wildner case 6 :
492*a28cd43dSSascha Wildner return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, 6);
493*a28cd43dSSascha Wildner case 7 :
494*a28cd43dSSascha Wildner return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, 7);
495*a28cd43dSSascha Wildner }
496*a28cd43dSSascha Wildner }
497