diff --git a/lib/compress/zstd_lazy.c b/lib/compress/zstd_lazy.c index aa932b51..94d906c0 100644 --- a/lib/compress/zstd_lazy.c +++ b/lib/compress/zstd_lazy.c @@ -83,7 +83,10 @@ ZSTD_insertDUBT1(ZSTD_matchState_t* ms, U32* largerPtr = smallerPtr + 1; U32 matchIndex = *smallerPtr; /* this candidate is unsorted : next sorted candidate is reached through *smallerPtr, while *largerPtr contains previous unsorted candidate (which is already saved and can be overwritten) */ U32 dummy32; /* to be nullified at the end */ - U32 const windowLow = ms->window.lowLimit; + U32 const windowValid = ms->window.lowLimit; + U32 const maxDistance = 1U << cParams->windowLog; + U32 const windowLow = (current - windowValid > maxDistance) ? current - maxDistance : windowValid; + DEBUGLOG(8, "ZSTD_insertDUBT1(%u) (dictLimit=%u, lowLimit=%u)", current, dictLimit, windowLow); @@ -239,7 +242,9 @@ ZSTD_DUBT_findBestMatch(ZSTD_matchState_t* ms, const BYTE* const base = ms->window.base; U32 const current = (U32)(ip-base); - U32 const windowLow = ms->window.lowLimit; + U32 const maxDistance = 1U << cParams->windowLog; + U32 const windowValid = ms->window.lowLimit; + U32 const windowLow = (current - windowValid > maxDistance) ? current - maxDistance : windowValid; U32* const bt = ms->chainTable; U32 const btLog = cParams->chainLog - 1; @@ -490,8 +495,10 @@ size_t ZSTD_HcFindBestMatch_generic ( const U32 dictLimit = ms->window.dictLimit; const BYTE* const prefixStart = base + dictLimit; const BYTE* const dictEnd = dictBase + dictLimit; - const U32 lowLimit = ms->window.lowLimit; const U32 current = (U32)(ip-base); + const U32 maxDistance = 1U << cParams->windowLog; + const U32 lowValid = ms->window.lowLimit; + const U32 lowLimit = (current - lowValid > maxDistance) ? current - maxDistance : lowValid; const U32 minChain = current > chainSize ? current - chainSize : 0; U32 nbAttempts = 1U << cParams->searchLog; size_t ml=4-1;