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path: root/thirdparty/zstd/compress/zstd_double_fast.c
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Diffstat (limited to 'thirdparty/zstd/compress/zstd_double_fast.c')
-rw-r--r--thirdparty/zstd/compress/zstd_double_fast.c92
1 files changed, 56 insertions, 36 deletions
diff --git a/thirdparty/zstd/compress/zstd_double_fast.c b/thirdparty/zstd/compress/zstd_double_fast.c
index 47faf6d641..5957255d90 100644
--- a/thirdparty/zstd/compress/zstd_double_fast.c
+++ b/thirdparty/zstd/compress/zstd_double_fast.c
@@ -43,8 +43,7 @@ void ZSTD_fillDoubleHashTable(ZSTD_matchState_t* ms,
/* Only load extra positions for ZSTD_dtlm_full */
if (dtlm == ZSTD_dtlm_fast)
break;
- }
- }
+ } }
}
@@ -63,7 +62,10 @@ size_t ZSTD_compressBlock_doubleFast_generic(
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
- const U32 prefixLowestIndex = ms->window.dictLimit;
+ const U32 endIndex = (U32)((size_t)(istart - base) + srcSize);
+ const U32 lowestValid = ms->window.dictLimit;
+ const U32 maxDistance = 1U << cParams->windowLog;
+ const U32 prefixLowestIndex = (endIndex - lowestValid > maxDistance) ? endIndex - maxDistance : lowestValid;
const BYTE* const prefixLowest = base + prefixLowestIndex;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - HASH_READ_SIZE;
@@ -95,8 +97,15 @@ size_t ZSTD_compressBlock_doubleFast_generic(
dictCParams->chainLog : hBitsS;
const U32 dictAndPrefixLength = (U32)(ip - prefixLowest + dictEnd - dictStart);
+ DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_generic");
+
assert(dictMode == ZSTD_noDict || dictMode == ZSTD_dictMatchState);
+ /* if a dictionary is attached, it must be within window range */
+ if (dictMode == ZSTD_dictMatchState) {
+ assert(lowestValid + maxDistance >= endIndex);
+ }
+
/* init */
ip += (dictAndPrefixLength == 0);
if (dictMode == ZSTD_noDict) {
@@ -138,7 +147,7 @@ size_t ZSTD_compressBlock_doubleFast_generic(
const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
ip++;
- ZSTD_storeSeq(seqStore, ip-anchor, anchor, 0, mLength-MINMATCH);
+ ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, 0, mLength-MINMATCH);
goto _match_stored;
}
@@ -147,7 +156,7 @@ size_t ZSTD_compressBlock_doubleFast_generic(
&& ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1)))) {
mLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
ip++;
- ZSTD_storeSeq(seqStore, ip-anchor, anchor, 0, mLength-MINMATCH);
+ ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, 0, mLength-MINMATCH);
goto _match_stored;
}
@@ -170,8 +179,7 @@ size_t ZSTD_compressBlock_doubleFast_generic(
offset = (U32)(current - dictMatchIndexL - dictIndexDelta);
while (((ip>anchor) & (dictMatchL>dictStart)) && (ip[-1] == dictMatchL[-1])) { ip--; dictMatchL--; mLength++; } /* catch up */
goto _match_found;
- }
- }
+ } }
if (matchIndexS > prefixLowestIndex) {
/* check prefix short match */
@@ -186,16 +194,14 @@ size_t ZSTD_compressBlock_doubleFast_generic(
if (match > dictStart && MEM_read32(match) == MEM_read32(ip)) {
goto _search_next_long;
- }
- }
+ } }
ip += ((ip-anchor) >> kSearchStrength) + 1;
continue;
_search_next_long:
- {
- size_t const hl3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
+ { size_t const hl3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
size_t const dictHLNext = ZSTD_hashPtr(ip+1, dictHBitsL, 8);
U32 const matchIndexL3 = hashLong[hl3];
const BYTE* matchL3 = base + matchIndexL3;
@@ -221,9 +227,7 @@ _search_next_long:
offset = (U32)(current + 1 - dictMatchIndexL3 - dictIndexDelta);
while (((ip>anchor) & (dictMatchL3>dictStart)) && (ip[-1] == dictMatchL3[-1])) { ip--; dictMatchL3--; mLength++; } /* catch up */
goto _match_found;
- }
- }
- }
+ } } }
/* if no long +1 match, explore the short match we found */
if (dictMode == ZSTD_dictMatchState && matchIndexS < prefixLowestIndex) {
@@ -242,7 +246,7 @@ _match_found:
offset_2 = offset_1;
offset_1 = offset;
- ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
+ ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
_match_stored:
/* match found */
@@ -250,11 +254,14 @@ _match_stored:
anchor = ip;
if (ip <= ilimit) {
- /* Fill Table */
- hashLong[ZSTD_hashPtr(base+current+2, hBitsL, 8)] =
- hashSmall[ZSTD_hashPtr(base+current+2, hBitsS, mls)] = current+2; /* here because current+2 could be > iend-8 */
- hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] =
- hashSmall[ZSTD_hashPtr(ip-2, hBitsS, mls)] = (U32)(ip-2-base);
+ /* Complementary insertion */
+ /* done after iLimit test, as candidates could be > iend-8 */
+ { U32 const indexToInsert = current+2;
+ hashLong[ZSTD_hashPtr(base+indexToInsert, hBitsL, 8)] = indexToInsert;
+ hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base);
+ hashSmall[ZSTD_hashPtr(base+indexToInsert, hBitsS, mls)] = indexToInsert;
+ hashSmall[ZSTD_hashPtr(ip-1, hBitsS, mls)] = (U32)(ip-1-base);
+ }
/* check immediate repcode */
if (dictMode == ZSTD_dictMatchState) {
@@ -278,8 +285,7 @@ _match_stored:
continue;
}
break;
- }
- }
+ } }
if (dictMode == ZSTD_noDict) {
while ( (ip <= ilimit)
@@ -294,14 +300,15 @@ _match_stored:
ip += rLength;
anchor = ip;
continue; /* faster when present ... (?) */
- } } } }
+ } } }
+ } /* while (ip < ilimit) */
/* save reps for next block */
rep[0] = offset_1 ? offset_1 : offsetSaved;
rep[1] = offset_2 ? offset_2 : offsetSaved;
/* Return the last literals size */
- return iend - anchor;
+ return (size_t)(iend - anchor);
}
@@ -360,10 +367,15 @@ static size_t ZSTD_compressBlock_doubleFast_extDict_generic(
const BYTE* anchor = istart;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
- const U32 prefixStartIndex = ms->window.dictLimit;
const BYTE* const base = ms->window.base;
+ const U32 endIndex = (U32)((size_t)(istart - base) + srcSize);
+ const U32 maxDistance = 1U << cParams->windowLog;
+ const U32 lowestValid = ms->window.lowLimit;
+ const U32 lowLimit = (endIndex - lowestValid > maxDistance) ? endIndex - maxDistance : lowestValid;
+ const U32 dictStartIndex = lowLimit;
+ const U32 dictLimit = ms->window.dictLimit;
+ const U32 prefixStartIndex = (dictLimit > lowLimit) ? dictLimit : lowLimit;
const BYTE* const prefixStart = base + prefixStartIndex;
- const U32 dictStartIndex = ms->window.lowLimit;
const BYTE* const dictBase = ms->window.dictBase;
const BYTE* const dictStart = dictBase + dictStartIndex;
const BYTE* const dictEnd = dictBase + prefixStartIndex;
@@ -371,6 +383,10 @@ static size_t ZSTD_compressBlock_doubleFast_extDict_generic(
DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_extDict_generic (srcSize=%zu)", srcSize);
+ /* if extDict is invalidated due to maxDistance, switch to "regular" variant */
+ if (prefixStartIndex == dictStartIndex)
+ return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, mls, ZSTD_noDict);
+
/* Search Loop */
while (ip < ilimit) { /* < instead of <=, because (ip+1) */
const size_t hSmall = ZSTD_hashPtr(ip, hBitsS, mls);
@@ -396,7 +412,7 @@ static size_t ZSTD_compressBlock_doubleFast_extDict_generic(
const BYTE* repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixStart) + 4;
ip++;
- ZSTD_storeSeq(seqStore, ip-anchor, anchor, 0, mLength-MINMATCH);
+ ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, 0, mLength-MINMATCH);
} else {
if ((matchLongIndex > dictStartIndex) && (MEM_read64(matchLong) == MEM_read64(ip))) {
const BYTE* const matchEnd = matchLongIndex < prefixStartIndex ? dictEnd : iend;
@@ -407,7 +423,7 @@ static size_t ZSTD_compressBlock_doubleFast_extDict_generic(
while (((ip>anchor) & (matchLong>lowMatchPtr)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */
offset_2 = offset_1;
offset_1 = offset;
- ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
+ ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
} else if ((matchIndex > dictStartIndex) && (MEM_read32(match) == MEM_read32(ip))) {
size_t const h3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
@@ -432,23 +448,27 @@ static size_t ZSTD_compressBlock_doubleFast_extDict_generic(
}
offset_2 = offset_1;
offset_1 = offset;
- ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
+ ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
} else {
ip += ((ip-anchor) >> kSearchStrength) + 1;
continue;
} }
- /* found a match : store it */
+ /* move to next sequence start */
ip += mLength;
anchor = ip;
if (ip <= ilimit) {
- /* Fill Table */
- hashSmall[ZSTD_hashPtr(base+current+2, hBitsS, mls)] = current+2;
- hashLong[ZSTD_hashPtr(base+current+2, hBitsL, 8)] = current+2;
- hashSmall[ZSTD_hashPtr(ip-2, hBitsS, mls)] = (U32)(ip-2-base);
- hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base);
+ /* Complementary insertion */
+ /* done after iLimit test, as candidates could be > iend-8 */
+ { U32 const indexToInsert = current+2;
+ hashLong[ZSTD_hashPtr(base+indexToInsert, hBitsL, 8)] = indexToInsert;
+ hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base);
+ hashSmall[ZSTD_hashPtr(base+indexToInsert, hBitsS, mls)] = indexToInsert;
+ hashSmall[ZSTD_hashPtr(ip-1, hBitsS, mls)] = (U32)(ip-1-base);
+ }
+
/* check immediate repcode */
while (ip <= ilimit) {
U32 const current2 = (U32)(ip-base);
@@ -475,7 +495,7 @@ static size_t ZSTD_compressBlock_doubleFast_extDict_generic(
rep[1] = offset_2;
/* Return the last literals size */
- return iend - anchor;
+ return (size_t)(iend - anchor);
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-01 11:23:34 +0000