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fix compression bug (extDict mode)

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This commit is contained in:
Yann Collet
2015-11-17 14:26:54 +01:00
parent 786eb7d42e
commit 138e89c9c4
1 changed files with 6 additions and 4 deletions
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lib/zstd_compress.c
+6 -4
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@@ -823,7 +823,7 @@ size_t ZSTD_compressBlock_fast_extDict_generic(ZSTD_CCtx* ctx,
const BYTE* const iend = istart + srcSize; const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8; const BYTE* const ilimit = iend - 8;
size_t offset_2=REPCODE_STARTVALUE, offset_1=REPCODE_STARTVALUE; U32 offset_2=REPCODE_STARTVALUE, offset_1=REPCODE_STARTVALUE;
/* init */ /* init */
@@ -846,7 +846,7 @@ size_t ZSTD_compressBlock_fast_extDict_generic(ZSTD_CCtx* ctx,
const BYTE* lowMatchPtr = matchIndex < dictLimit ? dictBase + lowLimit : base + dictLimit; const BYTE* lowMatchPtr = matchIndex < dictLimit ? dictBase + lowLimit : base + dictLimit;
const BYTE* match = matchBase + matchIndex; const BYTE* match = matchBase + matchIndex;
const U32 current = (U32)(ip-base); const U32 current = (U32)(ip-base);
const U32 repIndex = current - (U32)offset_2; const U32 repIndex = current - offset_2;
const BYTE* repBase = repIndex < dictLimit ? dictBase : base; const BYTE* repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* repMatch = repBase + repIndex; const BYTE* repMatch = repBase + repIndex;
hashTable[h] = current; /* update hash table */ hashTable[h] = current; /* update hash table */
@@ -863,10 +863,12 @@ size_t ZSTD_compressBlock_fast_extDict_generic(ZSTD_CCtx* ctx,
{ {
size_t litLength = ip-anchor; size_t litLength = ip-anchor;
size_t maxLength = matchIndex < dictLimit ? MIN((size_t)(iend-ip-MINMATCH), (size_t)(dictLimit - matchIndex)) : (size_t)(iend-ip-MINMATCH); const BYTE* matchEnd = matchIndex < dictLimit ? dictBase + dictLimit : iend;
const BYTE* const iEndCount = ip + maxLength; const BYTE* iEndCount = (matchEnd - match < iend - ip) ? ip + (matchEnd - match) : iend;
size_t matchLength = ZSTD_count(ip+MINMATCH, match+MINMATCH, iEndCount); size_t matchLength = ZSTD_count(ip+MINMATCH, match+MINMATCH, iEndCount);
size_t offsetCode = current-matchIndex; size_t offsetCode = current-matchIndex;
if (matchIndex + matchLength + MINMATCH == dictLimit)
matchLength += ZSTD_count(ip + matchLength + MINMATCH, base + dictLimit, iend);
if (offsetCode == offset_2) offsetCode = 0; if (offsetCode == offset_2) offsetCode = 0;
offset_2 = offset_1; offset_2 = offset_1;
offset_1 = current-matchIndex; offset_1 = current-matchIndex;