diff options
| -rw-r--r-- | lib/lz4hc.c | 21 | ||||
| -rw-r--r-- | lib/lz4opt.h | 4 |
2 files changed, 17 insertions, 8 deletions
diff --git a/lib/lz4hc.c b/lib/lz4hc.c index e6d496c..f2c2566 100644 --- a/lib/lz4hc.c +++ b/lib/lz4hc.c @@ -191,7 +191,8 @@ LZ4_FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch ( int longest, const BYTE** matchpos, const BYTE** startpos, - const int maxNbAttempts) + const int maxNbAttempts, + const int patternAnalysis) { U16* const chainTable = hc4->chainTable; U32* const HashTable = hc4->hashTable; @@ -264,7 +265,7 @@ LZ4_FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch ( { U32 const nextOffset = DELTANEXTU16(chainTable, matchIndex); matchIndex -= nextOffset; - if (nextOffset==1) { + if (patternAnalysis && nextOffset==1) { /* may be a repeated pattern */ if (repeat == rep_untested) { if ( ((pattern & 0xFFFF) == (pattern >> 16)) @@ -299,13 +300,14 @@ LZ4_FORCE_INLINE int LZ4HC_InsertAndFindBestMatch(LZ4HC_CCtx_internal* const hc4, /* Index table will be updated */ const BYTE* const ip, const BYTE* const iLimit, const BYTE** matchpos, - const int maxNbAttempts) + const int maxNbAttempts, + const int patternAnalysis) { const BYTE* uselessPtr = ip; /* note : LZ4HC_InsertAndGetWiderMatch() is able to modify the starting position of a match (*startpos), * but this won't be the case here, as we define iLowLimit==ip, * so LZ4HC_InsertAndGetWiderMatch() won't be allowed to search past ip */ - return LZ4HC_InsertAndGetWiderMatch(hc4, ip, ip, iLimit, MINMATCH-1, matchpos, &uselessPtr, maxNbAttempts); + return LZ4HC_InsertAndGetWiderMatch(hc4, ip, ip, iLimit, MINMATCH-1, matchpos, &uselessPtr, maxNbAttempts, patternAnalysis); } @@ -403,6 +405,7 @@ static int LZ4HC_compress_hashChain ( ) { const int inputSize = *srcSizePtr; + const int patternAnalysis = (maxNbAttempts > 64); /* levels 8+ */ const BYTE* ip = (const BYTE*) source; const BYTE* anchor = ip; @@ -430,7 +433,7 @@ static int LZ4HC_compress_hashChain ( /* Main Loop */ while (ip < mflimit) { - ml = LZ4HC_InsertAndFindBestMatch (ctx, ip, matchlimit, &ref, maxNbAttempts); + ml = LZ4HC_InsertAndFindBestMatch (ctx, ip, matchlimit, &ref, maxNbAttempts, patternAnalysis); if (ml<MINMATCH) { ip++; continue; } /* saved, in case we would skip too much */ @@ -440,7 +443,9 @@ static int LZ4HC_compress_hashChain ( _Search2: if (ip+ml < mflimit) - ml2 = LZ4HC_InsertAndGetWiderMatch(ctx, ip + ml - 2, ip + 0, matchlimit, ml, &ref2, &start2, maxNbAttempts); + ml2 = LZ4HC_InsertAndGetWiderMatch(ctx, + ip + ml - 2, ip + 0, matchlimit, ml, &ref2, &start2, + maxNbAttempts, patternAnalysis); else ml2 = ml; @@ -485,7 +490,9 @@ _Search3: /* Now, we have start2 = ip+new_ml, with new_ml = min(ml, OPTIMAL_ML=18) */ if (start2 + ml2 < mflimit) - ml3 = LZ4HC_InsertAndGetWiderMatch(ctx, start2 + ml2 - 3, start2, matchlimit, ml2, &ref3, &start3, maxNbAttempts); + ml3 = LZ4HC_InsertAndGetWiderMatch(ctx, + start2 + ml2 - 3, start2, matchlimit, ml2, &ref3, &start3, + maxNbAttempts, patternAnalysis); else ml3 = ml2; diff --git a/lib/lz4opt.h b/lib/lz4opt.h index 58068bf..5a8438c 100644 --- a/lib/lz4opt.h +++ b/lib/lz4opt.h @@ -85,7 +85,9 @@ LZ4HC_match_t LZ4HC_FindLongerMatch(LZ4HC_CCtx_internal* const ctx, /* note : LZ4HC_InsertAndGetWiderMatch() is able to modify the starting position of a match (*startpos), * but this won't be the case here, as we define iLowLimit==ip, * so LZ4HC_InsertAndGetWiderMatch() won't be allowed to search past ip */ - int const matchLength = LZ4HC_InsertAndGetWiderMatch(ctx, ip, ip, iHighLimit, minLen, &matchPtr, &ip, nbSearches); + int const matchLength = LZ4HC_InsertAndGetWiderMatch(ctx, + ip, ip, iHighLimit, minLen, &matchPtr, &ip, + nbSearches, 1 /* patternAnalysis */); if (matchLength <= minLen) return match; match.len = matchLength; match.off = (int)(ip-matchPtr); |