diff options
Diffstat (limited to 'thirdparty/zstd/compress/zstd_fast.c')
| -rw-r--r-- | thirdparty/zstd/compress/zstd_fast.c | 49 |
1 files changed, 35 insertions, 14 deletions
diff --git a/thirdparty/zstd/compress/zstd_fast.c b/thirdparty/zstd/compress/zstd_fast.c index ed997b441c..a05b8a47f1 100644 --- a/thirdparty/zstd/compress/zstd_fast.c +++ b/thirdparty/zstd/compress/zstd_fast.c @@ -13,7 +13,8 @@ void ZSTD_fillHashTable(ZSTD_matchState_t* ms, - void const* end, ZSTD_dictTableLoadMethod_e dtlm) + const void* const end, + ZSTD_dictTableLoadMethod_e dtlm) { const ZSTD_compressionParameters* const cParams = &ms->cParams; U32* const hashTable = ms->hashTable; @@ -41,6 +42,7 @@ void ZSTD_fillHashTable(ZSTD_matchState_t* ms, } } } } } + FORCE_INLINE_TEMPLATE size_t ZSTD_compressBlock_fast_generic( ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], @@ -58,7 +60,10 @@ size_t ZSTD_compressBlock_fast_generic( const BYTE* ip0 = istart; const BYTE* ip1; const BYTE* anchor = istart; - const U32 prefixStartIndex = ms->window.dictLimit; + const U32 endIndex = (U32)((size_t)(istart - base) + srcSize); + const U32 maxDistance = 1U << cParams->windowLog; + const U32 validStartIndex = ms->window.dictLimit; + const U32 prefixStartIndex = (endIndex - validStartIndex > maxDistance) ? endIndex - maxDistance : validStartIndex; const BYTE* const prefixStart = base + prefixStartIndex; const BYTE* const iend = istart + srcSize; const BYTE* const ilimit = iend - HASH_READ_SIZE; @@ -165,7 +170,7 @@ _match: /* Requires: ip0, match0, offcode */ rep[1] = offset_2 ? offset_2 : offsetSaved; /* Return the last literals size */ - return iend - anchor; + return (size_t)(iend - anchor); } @@ -222,8 +227,15 @@ size_t ZSTD_compressBlock_fast_dictMatchState_generic( const U32 dictAndPrefixLength = (U32)(ip - prefixStart + dictEnd - dictStart); const U32 dictHLog = dictCParams->hashLog; - /* otherwise, we would get index underflow when translating a dict index - * into a local index */ + /* if a dictionary is still attached, it necessarily means that + * it is within window size. So we just check it. */ + const U32 maxDistance = 1U << cParams->windowLog; + const U32 endIndex = (U32)((size_t)(ip - base) + srcSize); + assert(endIndex - prefixStartIndex <= maxDistance); + (void)maxDistance; (void)endIndex; /* these variables are not used when assert() is disabled */ + + /* ensure there will be no no underflow + * when translating a dict index into a local index */ assert(prefixStartIndex >= (U32)(dictEnd - dictBase)); /* init */ @@ -251,7 +263,7 @@ size_t ZSTD_compressBlock_fast_dictMatchState_generic( const BYTE* const 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 ( (matchIndex <= prefixStartIndex) ) { size_t const dictHash = ZSTD_hashPtr(ip, dictHLog, mls); U32 const dictMatchIndex = dictHashTable[dictHash]; @@ -271,7 +283,7 @@ size_t ZSTD_compressBlock_fast_dictMatchState_generic( } /* 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 (MEM_read32(match) != MEM_read32(ip)) { /* it's not a match, and we're not going to check the dictionary */ @@ -286,7 +298,7 @@ size_t ZSTD_compressBlock_fast_dictMatchState_generic( && (ip[-1] == match[-1])) { ip--; match--; 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); } /* match found */ @@ -327,7 +339,7 @@ size_t ZSTD_compressBlock_fast_dictMatchState_generic( rep[1] = offset_2 ? offset_2 : offsetSaved; /* Return the last literals size */ - return iend - anchor; + return (size_t)(iend - anchor); } size_t ZSTD_compressBlock_fast_dictMatchState( @@ -366,15 +378,24 @@ static size_t ZSTD_compressBlock_fast_extDict_generic( const BYTE* const istart = (const BYTE*)src; const BYTE* ip = istart; const BYTE* anchor = istart; - const U32 dictStartIndex = ms->window.lowLimit; + const U32 endIndex = (U32)((size_t)(istart - base) + srcSize); + const U32 maxDistance = 1U << cParams->windowLog; + const U32 validLow = ms->window.lowLimit; + const U32 lowLimit = (endIndex - validLow > maxDistance) ? endIndex - maxDistance : validLow; + const U32 dictStartIndex = lowLimit; const BYTE* const dictStart = dictBase + dictStartIndex; - const U32 prefixStartIndex = ms->window.dictLimit; + const U32 dictLimit = ms->window.dictLimit; + const U32 prefixStartIndex = dictLimit < lowLimit ? lowLimit : dictLimit; const BYTE* const prefixStart = base + prefixStartIndex; const BYTE* const dictEnd = dictBase + prefixStartIndex; const BYTE* const iend = istart + srcSize; const BYTE* const ilimit = iend - 8; U32 offset_1=rep[0], offset_2=rep[1]; + /* switch to "regular" variant if extDict is invalidated due to maxDistance */ + if (prefixStartIndex == dictStartIndex) + return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, mls); + /* Search Loop */ while (ip < ilimit) { /* < instead of <=, because (ip+1) */ const size_t h = ZSTD_hashPtr(ip, hlog, mls); @@ -394,7 +415,7 @@ static size_t ZSTD_compressBlock_fast_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 ( (matchIndex < dictStartIndex) || (MEM_read32(match) != MEM_read32(ip)) ) { @@ -410,7 +431,7 @@ static size_t ZSTD_compressBlock_fast_extDict_generic( offset = current - matchIndex; 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); } } /* found a match : store it */ @@ -445,7 +466,7 @@ static size_t ZSTD_compressBlock_fast_extDict_generic( rep[1] = offset_2; /* Return the last literals size */ - return iend - anchor; + return (size_t)(iend - anchor); } |