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-rw-r--r--lib/lz4hc.c134
1 files changed, 20 insertions, 114 deletions
diff --git a/lib/lz4hc.c b/lib/lz4hc.c
index c58cd9d..7e2fcb3 100644
--- a/lib/lz4hc.c
+++ b/lib/lz4hc.c
@@ -280,10 +280,29 @@ LZ4HC_InsertAndGetWiderMatch (
*startpos = ip + back;
} } }
+ if (mlt == longest) { /* better match => select a better chain */
+ assert(longest >= MINMATCH);
+ if (1 && matchIndex + longest <= ipIndex) {
+ U32 distanceToNextMatch = 1;
+ int pos;
+ for (pos = 0; pos <= longest - MINMATCH; pos++) {
+ U32 const candidateDist = DELTANEXTU16(chainTable, matchIndex + pos);
+ if (candidateDist > distanceToNextMatch) {
+ distanceToNextMatch = candidateDist;
+ matchChainPos = pos;
+ }
+ }
+ if (distanceToNextMatch > 1) {
+ if (distanceToNextMatch > matchIndex) break; /* avoid overflow */
+ matchIndex -= distanceToNextMatch;
+ continue;
+ }
+ }
+ }
+
{ U32 const distNextMatch = DELTANEXTU16(chainTable, matchIndex);
if (1 && patternAnalysis && distNextMatch==1 && matchChainPos==0) {
U32 const matchCandidateIdx = matchIndex-1;
- //static U64 g_nbPatternAnalysis = 0; g_nbPatternAnalysis++; if (g_nbPatternAnalysis % (((g_nbPatternAnalysis/1000000)+1)*100)==0) DEBUGLOG(2, "g_nbPatternAnalysis=%llu ", g_nbPatternAnalysis);
/* may be a repeated pattern */
if (repeat == rep_untested) {
if ( ((pattern & 0xFFFF) == (pattern >> 16))
@@ -301,7 +320,6 @@ LZ4HC_InsertAndGetWiderMatch (
const BYTE* const maxLowPtr = (lowPrefixPtr + MAX_DISTANCE >= ip) ? lowPrefixPtr : ip - MAX_DISTANCE;
size_t const backLength = LZ4HC_reverseCountPattern(matchPtr, maxLowPtr, pattern);
size_t const currentSegmentLength = backLength + forwardPatternLength;
- //static U64 g_nbPatternAnalysis_confirmed = 0; g_nbPatternAnalysis_confirmed++; if (g_nbPatternAnalysis_confirmed%(((g_nbPatternAnalysis_confirmed/100000)+1)*100)==0) DEBUGLOG(2, "g_nbPatternAnalysis_confirmed=%llu ", g_nbPatternAnalysis_confirmed);
if ( (currentSegmentLength >= srcPatternLength) /* current pattern segment large enough to contain full srcPatternLength */
&& (forwardPatternLength <= srcPatternLength) ) { /* haven't reached this position yet */
@@ -314,25 +332,6 @@ LZ4HC_InsertAndGetWiderMatch (
} }
} }
- if (mlt == longest) { /* better match => select a better chain */
- assert(longest >= MINMATCH);
- if (1 && matchIndex + longest <= ipIndex) {
- U32 distanceToNextMatch = 1;
- int pos;
- //static U64 g_nbChainSwapper = 0; g_nbChainSwapper++; if (g_nbChainSwapper%(((g_nbChainSwapper/100000)+1)*100)==0) DEBUGLOG(2, "g_nbChainSwapper=%llu ", g_nbChainSwapper);
- for (pos = matchChainPos; pos <= longest - MINMATCH; pos++) {
- U32 const candidateDist = DELTANEXTU16(chainTable, matchIndex + pos);
- if (candidateDist > distanceToNextMatch) {
- distanceToNextMatch = candidateDist;
- matchChainPos = pos;
- }
- }
- if (distanceToNextMatch > matchIndex) break; /* avoid overflow */
- matchIndex -= distanceToNextMatch;
- continue;
- }
- }
-
/* follow current chain */
matchIndex -= DELTANEXTU16(chainTable, matchIndex+matchChainPos);
@@ -1112,98 +1111,6 @@ LZ4_FORCE_INLINE int LZ4HC_sequencePrice(int litlen, int mlen)
}
-int
-LZ4HC_FindLongestMatch (LZ4HC_CCtx_internal* hc4,
- const BYTE* const ip,
- const BYTE* const iHighLimit,
- int longest,
- const BYTE** matchpos,
- const int maxNbAttempts)
-{
- U16* const chainTable = hc4->chainTable;
- U32* const HashTable = hc4->hashTable;
- const BYTE* const base = hc4->base;
- const U32 ipIndex = (U32)(ip - base);
- const U32 lowestMatchIndex = (hc4->lowLimit + 64 KB > ipIndex) ? hc4->lowLimit : ipIndex - MAX_DISTANCE;
- int nbAttempts = maxNbAttempts;
- U32 const pattern = LZ4_read32(ip);
- U32 matchIndex;
- int matchChainPos = 0;
-
- DEBUGLOG(7, "LZ4HC_InsertAndGetWiderMatch");
- /* First Match */
- LZ4HC_Insert(hc4, ip);
- matchIndex = HashTable[LZ4HC_hashPtr(ip)];
- DEBUGLOG(7, "First match at index %u / %u (lowestMatchIndex)",
- matchIndex, lowestMatchIndex);
-
- /* find first match */
- while ( 1 && (longest < MINMATCH)
- && (matchIndex>=lowestMatchIndex)
- && (nbAttempts) ) {
- const BYTE* const matchPtr = base + matchIndex;
- assert(matchIndex < ipIndex);
- assert(matchPtr < ip);
- assert(longest >= 1);
- nbAttempts--;
- if (LZ4_read32(matchPtr) == pattern) {
- int const mlt = MINMATCH + LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit);
- if (mlt > longest) {
- longest = mlt;
- *matchpos = matchPtr;
- } }
-
- { U32 const nextOffset = DELTANEXTU16(chainTable, matchIndex);
- matchIndex -= nextOffset;
- }
- } /* while ((matchIndex>=lowestMatchIndex) && (nbAttempts)) */
-
- /* search longer matches */
- while ((matchIndex>=lowestMatchIndex) && (nbAttempts)) {
- const BYTE* const matchPtr = base + matchIndex;
- int mlt = 0;
- assert(matchIndex < ipIndex);
- assert(matchPtr < ip);
- assert(longest >= MINMATCH);
- nbAttempts--;
- if (LZ4_read16(ip + longest - 1) == LZ4_read16(matchPtr + longest - 1)) {
- if (LZ4_read32(matchPtr) == pattern) {
- mlt = MINMATCH + LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit);
- if (mlt > longest) {
- longest = mlt;
- *matchpos = matchPtr;
- }
- }
- }
-
- /* search more promising chain */
- if (mlt == longest) {
- if (1 && matchIndex + longest <= ipIndex) {
- U32 distanceToNextMatch = 1;
- int pos;
- for (pos = matchChainPos; pos <= longest - MINMATCH; pos++) {
- U32 const candidateDist = DELTANEXTU16(chainTable, matchIndex + pos);
- if (candidateDist > distanceToNextMatch) {
- distanceToNextMatch = candidateDist;
- matchChainPos = pos;
- }
- }
- if (distanceToNextMatch > matchIndex) break; /* avoid overflow */
- matchIndex -= distanceToNextMatch;
- continue;
- }
- }
-
- /* continue current chain */
- { U32 const nextOffset = DELTANEXTU16(chainTable, matchIndex+matchChainPos);
- matchIndex -= nextOffset;
- }
- } /* while ((matchIndex>=lowestMatchIndex) && (nbAttempts)) */
-
- return longest;
-}
-
-
typedef struct {
int off;
int len;
@@ -1222,7 +1129,6 @@ LZ4HC_FindLongerMatch(LZ4HC_CCtx_internal* const ctx,
* 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 matchLength = LZ4HC_InsertAndGetWiderMatch(ctx, ip, ip, iHighLimit, minLen, &matchPtr, &ip, nbSearches, 1 /* patternAnalysis */, dict, favorDecSpeed);
- //int matchLength = LZ4HC_FindLongestMatch(ctx, ip, iHighLimit, minLen, &matchPtr, nbSearches); (void)dict;
if (matchLength <= minLen) return match;
if (favorDecSpeed) {
if ((matchLength>18) & (matchLength<=36)) matchLength=18; /* favor shortcut */
generated by cgit v0.12 at 2024-11-02 14:42:50 (GMT)