diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/lz4hc.c | 172 | ||||
| -rw-r--r-- | lib/lz4hc.h | 4 |
2 files changed, 92 insertions, 84 deletions
diff --git a/lib/lz4hc.c b/lib/lz4hc.c index 77b4767..6b139fa 100644 --- a/lib/lz4hc.c +++ b/lib/lz4hc.c @@ -42,7 +42,7 @@ * Select how default compression function will allocate workplace memory, * in stack (0:fastest), or in heap (1:requires malloc()). * Since workplace is rather large, heap mode is recommended. - */ +**/ #ifndef LZ4HC_HEAPMODE # define LZ4HC_HEAPMODE 1 #endif @@ -99,18 +99,20 @@ static void LZ4HC_clearTables (LZ4HC_CCtx_internal* hc4) static void LZ4HC_init_internal (LZ4HC_CCtx_internal* hc4, const BYTE* start) { - uptrval startingOffset = (uptrval)(hc4->end - hc4->base); - if (startingOffset > 1 GB) { + size_t const bufferSize = (size_t)(hc4->end - hc4->prefixStart); + size_t newStartingOffset = bufferSize + hc4->dictLimit; + assert(newStartingOffset >= bufferSize); /* check overflow */ + if (newStartingOffset > 1 GB) { LZ4HC_clearTables(hc4); - startingOffset = 0; + newStartingOffset = 0; } - startingOffset += 64 KB; - hc4->nextToUpdate = (U32) startingOffset; - hc4->base = start - startingOffset; + newStartingOffset += 64 KB; + hc4->nextToUpdate = (U32)newStartingOffset; + hc4->prefixStart = start; hc4->end = start; - hc4->dictBase = start - startingOffset; - hc4->dictLimit = (U32) startingOffset; - hc4->lowLimit = (U32) startingOffset; + hc4->dictStart = start; + hc4->dictLimit = (U32)newStartingOffset; + hc4->lowLimit = (U32)newStartingOffset; } @@ -119,12 +121,15 @@ LZ4_FORCE_INLINE void LZ4HC_Insert (LZ4HC_CCtx_internal* hc4, const BYTE* ip) { U16* const chainTable = hc4->chainTable; U32* const hashTable = hc4->hashTable; - const BYTE* const base = hc4->base; - U32 const target = (U32)(ip - base); + const BYTE* const prefixPtr = hc4->prefixStart; + U32 const prefixIdx = hc4->dictLimit; + U32 const target = (U32)(ip - prefixPtr) + prefixIdx; U32 idx = hc4->nextToUpdate; + assert(ip >= prefixPtr); + assert(target >= prefixIdx); while (idx < target) { - U32 const h = LZ4HC_hashPtr(base+idx); + U32 const h = LZ4HC_hashPtr(prefixPtr+idx-prefixIdx); size_t delta = idx - hashTable[h]; if (delta>LZ4_DISTANCE_MAX) delta = LZ4_DISTANCE_MAX; DELTANEXTU16(chainTable, idx) = (U16)delta; @@ -247,13 +252,14 @@ LZ4HC_InsertAndGetWiderMatch ( U16* const chainTable = hc4->chainTable; U32* const HashTable = hc4->hashTable; const LZ4HC_CCtx_internal * const dictCtx = hc4->dictCtx; - const BYTE* const base = hc4->base; - const U32 dictLimit = hc4->dictLimit; - const BYTE* const lowPrefixPtr = base + dictLimit; - const U32 ipIndex = (U32)(ip - base); + const BYTE* const prefixPtr = hc4->prefixStart; + const U32 prefixIdx = hc4->dictLimit; + const U32 ipIndex = (U32)(ip - prefixPtr) + prefixIdx; const int withinStartDistance = (hc4->lowLimit + (LZ4_DISTANCE_MAX + 1) > ipIndex); const U32 lowestMatchIndex = (withinStartDistance) ? hc4->lowLimit : ipIndex - LZ4_DISTANCE_MAX; - const BYTE* const dictBase = hc4->dictBase; + const BYTE* const dictStart = hc4->dictStart; + const U32 dictIdx = hc4->lowLimit; + const BYTE* const dictEnd = dictStart + prefixIdx - dictIdx; int const lookBackLength = (int)(ip-iLowLimit); int nbAttempts = maxNbAttempts; U32 matchChainPos = 0; @@ -275,16 +281,13 @@ LZ4HC_InsertAndGetWiderMatch ( assert(matchIndex < ipIndex); if (favorDecSpeed && (ipIndex - matchIndex < 8)) { /* do nothing */ - } else if (matchIndex >= dictLimit) { /* within current Prefix */ - const BYTE* const matchPtr = base + matchIndex; - DEBUGLOG(2, "matchPtr = %p", matchPtr); - DEBUGLOG(2, "lowPrefixPtr = %p", lowPrefixPtr); - assert(matchPtr >= lowPrefixPtr); + } else if (matchIndex >= prefixIdx) { /* within current Prefix */ + const BYTE* const matchPtr = prefixPtr + matchIndex - prefixIdx; assert(matchPtr < ip); assert(longest >= 1); if (LZ4_read16(iLowLimit + longest - 1) == LZ4_read16(matchPtr - lookBackLength + longest - 1)) { if (LZ4_read32(matchPtr) == pattern) { - int const back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, lowPrefixPtr) : 0; + int const back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, prefixPtr) : 0; matchLength = MINMATCH + (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit); matchLength -= back; if (matchLength > longest) { @@ -293,21 +296,21 @@ LZ4HC_InsertAndGetWiderMatch ( *startpos = ip + back; } } } } else { /* lowestMatchIndex <= matchIndex < dictLimit */ - const BYTE* const matchPtr = dictBase + matchIndex; - if ( likely(matchIndex <= dictLimit - 4) + const BYTE* const matchPtr = dictStart + (matchIndex - dictIdx); + assert(matchIndex >= dictIdx); + if ( likely(matchIndex <= prefixIdx - 4) && (LZ4_read32(matchPtr) == pattern) ) { - const BYTE* const dictStart = dictBase + hc4->lowLimit; int back = 0; - const BYTE* vLimit = ip + (dictLimit - matchIndex); + const BYTE* vLimit = ip + (prefixIdx - matchIndex); if (vLimit > iHighLimit) vLimit = iHighLimit; matchLength = (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH; if ((ip+matchLength == vLimit) && (vLimit < iHighLimit)) - matchLength += LZ4_count(ip+matchLength, lowPrefixPtr, iHighLimit); + matchLength += LZ4_count(ip+matchLength, prefixPtr, iHighLimit); back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictStart) : 0; matchLength -= back; if (matchLength > longest) { longest = matchLength; - *matchpos = base + matchIndex + back; /* virtual pos, relative to ip, to retrieve offset */ + *matchpos = prefixPtr - prefixIdx + matchIndex + back; /* virtual pos, relative to ip, to retrieve offset */ *startpos = ip + back; } } } @@ -347,23 +350,24 @@ LZ4HC_InsertAndGetWiderMatch ( repeat = rep_not; } } if ( (repeat == rep_confirmed) && (matchCandidateIdx >= lowestMatchIndex) - && LZ4HC_protectDictEnd(dictLimit, matchCandidateIdx) ) { - const int extDict = matchCandidateIdx < dictLimit; - const BYTE* const matchPtr = (extDict ? dictBase : base) + matchCandidateIdx; + && LZ4HC_protectDictEnd(prefixIdx, matchCandidateIdx) ) { + const int extDict = matchCandidateIdx < prefixIdx; + const BYTE* const matchPtr = (extDict ? dictStart - dictIdx : prefixPtr - prefixIdx) + matchCandidateIdx; if (LZ4_read32(matchPtr) == pattern) { /* good candidate */ - const BYTE* const dictStart = dictBase + hc4->lowLimit; - const BYTE* const iLimit = extDict ? dictBase + dictLimit : iHighLimit; + const BYTE* const iLimit = extDict ? dictEnd : iHighLimit; size_t forwardPatternLength = LZ4HC_countPattern(matchPtr+sizeof(pattern), iLimit, pattern) + sizeof(pattern); if (extDict && matchPtr + forwardPatternLength == iLimit) { U32 const rotatedPattern = LZ4HC_rotatePattern(forwardPatternLength, pattern); - forwardPatternLength += LZ4HC_countPattern(lowPrefixPtr, iHighLimit, rotatedPattern); + forwardPatternLength += LZ4HC_countPattern(prefixPtr, iHighLimit, rotatedPattern); } - { const BYTE* const lowestMatchPtr = extDict ? dictStart : lowPrefixPtr; + { const BYTE* const lowestMatchPtr = extDict ? dictStart : prefixPtr; size_t backLength = LZ4HC_reverseCountPattern(matchPtr, lowestMatchPtr, pattern); size_t currentSegmentLength; - if (!extDict && matchPtr - backLength == lowPrefixPtr && hc4->lowLimit < dictLimit) { + if (!extDict + && matchPtr - backLength == prefixPtr + && dictIdx < prefixIdx) { U32 const rotatedPattern = LZ4HC_rotatePattern((U32)(-(int)backLength), pattern); - backLength += LZ4HC_reverseCountPattern(dictBase + dictLimit, dictStart, rotatedPattern); + backLength += LZ4HC_reverseCountPattern(dictEnd, dictStart, rotatedPattern); } /* Limit backLength not go further than lowestMatchIndex */ backLength = matchCandidateIdx - MAX(matchCandidateIdx - (U32)backLength, lowestMatchIndex); @@ -373,28 +377,28 @@ LZ4HC_InsertAndGetWiderMatch ( if ( (currentSegmentLength >= srcPatternLength) /* current pattern segment large enough to contain full srcPatternLength */ && (forwardPatternLength <= srcPatternLength) ) { /* haven't reached this position yet */ U32 const newMatchIndex = matchCandidateIdx + (U32)forwardPatternLength - (U32)srcPatternLength; /* best position, full pattern, might be followed by more match */ - if (LZ4HC_protectDictEnd(dictLimit, newMatchIndex)) + if (LZ4HC_protectDictEnd(prefixIdx, newMatchIndex)) matchIndex = newMatchIndex; else { /* Can only happen if started in the prefix */ - assert(newMatchIndex >= dictLimit - 3 && newMatchIndex < dictLimit && !extDict); - matchIndex = dictLimit; + assert(newMatchIndex >= prefixIdx - 3 && newMatchIndex < prefixIdx && !extDict); + matchIndex = prefixIdx; } } else { U32 const newMatchIndex = matchCandidateIdx - (U32)backLength; /* farthest position in current segment, will find a match of length currentSegmentLength + maybe some back */ - if (!LZ4HC_protectDictEnd(dictLimit, newMatchIndex)) { - assert(newMatchIndex >= dictLimit - 3 && newMatchIndex < dictLimit && !extDict); - matchIndex = dictLimit; + if (!LZ4HC_protectDictEnd(prefixIdx, newMatchIndex)) { + assert(newMatchIndex >= prefixIdx - 3 && newMatchIndex < prefixIdx && !extDict); + matchIndex = prefixIdx; } else { matchIndex = newMatchIndex; if (lookBackLength==0) { /* no back possible */ size_t const maxML = MIN(currentSegmentLength, srcPatternLength); if ((size_t)longest < maxML) { - assert(base + matchIndex != ip); - if ((size_t)(ip - base) - matchIndex > LZ4_DISTANCE_MAX) break; + assert(prefixPtr - prefixIdx + matchIndex != ip); + if ((size_t)(ip - prefixPtr) + prefixIdx - matchIndex > LZ4_DISTANCE_MAX) break; assert(maxML < 2 GB); longest = (int)maxML; - *matchpos = base + matchIndex; /* virtual pos, relative to ip, to retrieve offset */ + *matchpos = prefixPtr - prefixIdx + matchIndex; /* virtual pos, relative to ip, to retrieve offset */ *startpos = ip; } { U32 const distToNextPattern = DELTANEXTU16(chainTable, matchIndex); @@ -413,12 +417,12 @@ LZ4HC_InsertAndGetWiderMatch ( if ( dict == usingDictCtxHc && nbAttempts > 0 && ipIndex - lowestMatchIndex < LZ4_DISTANCE_MAX) { - size_t const dictEndOffset = (size_t)(dictCtx->end - dictCtx->base); + size_t const dictEndOffset = (size_t)(dictCtx->end - dictCtx->prefixStart) + dictCtx->dictLimit; U32 dictMatchIndex = dictCtx->hashTable[LZ4HC_hashPtr(ip)]; assert(dictEndOffset <= 1 GB); matchIndex = dictMatchIndex + lowestMatchIndex - (U32)dictEndOffset; while (ipIndex - matchIndex <= LZ4_DISTANCE_MAX && nbAttempts--) { - const BYTE* const matchPtr = dictCtx->base + dictMatchIndex; + const BYTE* const matchPtr = dictCtx->prefixStart - dictCtx->dictLimit + dictMatchIndex; if (LZ4_read32(matchPtr) == pattern) { int mlt; @@ -426,11 +430,11 @@ LZ4HC_InsertAndGetWiderMatch ( const BYTE* vLimit = ip + (dictEndOffset - dictMatchIndex); if (vLimit > iHighLimit) vLimit = iHighLimit; mlt = (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH; - back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictCtx->base + dictCtx->dictLimit) : 0; + back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictCtx->prefixStart) : 0; mlt -= back; if (mlt > longest) { longest = mlt; - *matchpos = base + matchIndex + back; + *matchpos = prefixPtr - prefixIdx + matchIndex + back; *startpos = ip + back; } } @@ -442,13 +446,13 @@ LZ4HC_InsertAndGetWiderMatch ( return longest; } -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 patternAnalysis, - const dictCtx_directive dict) +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 patternAnalysis, + const dictCtx_directive dict) { const BYTE* uselessPtr = ip; /* note : LZ4HC_InsertAndGetWiderMatch() is able to modify the starting position of a match (*startpos), @@ -884,7 +888,7 @@ LZ4HC_compress_generic_dictCtx ( limitedOutput_directive limit ) { - const size_t position = (size_t)(ctx->end - ctx->base) - ctx->lowLimit; + const size_t position = (size_t)(ctx->end - ctx->prefixStart) + (ctx->dictLimit - ctx->lowLimit); assert(ctx->dictCtx != NULL); if (position >= 64 KB) { ctx->dictCtx = NULL; @@ -1030,13 +1034,13 @@ void LZ4_resetStreamHC_fast (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLev if (LZ4_streamHCPtr->internal_donotuse.dirty) { LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr)); } else { - /* preserve end - base : can trigger clearTable's threshold */ + /* preserve end - prefixStart : can trigger clearTable's threshold */ if (LZ4_streamHCPtr->internal_donotuse.end != NULL) { - LZ4_streamHCPtr->internal_donotuse.end -= (uptrval)LZ4_streamHCPtr->internal_donotuse.base; + LZ4_streamHCPtr->internal_donotuse.end -= (uptrval)LZ4_streamHCPtr->internal_donotuse.prefixStart; } else { - assert(LZ4_streamHCPtr->internal_donotuse.base == NULL); + assert(LZ4_streamHCPtr->internal_donotuse.prefixStart == NULL); } - LZ4_streamHCPtr->internal_donotuse.base = NULL; + LZ4_streamHCPtr->internal_donotuse.prefixStart = NULL; LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL; } LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel); @@ -1087,14 +1091,14 @@ void LZ4_attach_HC_dictionary(LZ4_streamHC_t *working_stream, const LZ4_streamHC static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* ctxPtr, const BYTE* newBlock) { DEBUGLOG(4, "LZ4HC_setExternalDict(%p, %p)", ctxPtr, newBlock); - if (ctxPtr->end >= ctxPtr->base + ctxPtr->dictLimit + 4) + if (ctxPtr->end >= ctxPtr->prefixStart + 4) LZ4HC_Insert (ctxPtr, ctxPtr->end-3); /* Referencing remaining dictionary content */ /* Only one memory segment for extDict, so any previous extDict is lost at this stage */ ctxPtr->lowLimit = ctxPtr->dictLimit; - ctxPtr->dictLimit = (U32)(ctxPtr->end - ctxPtr->base); - ctxPtr->dictBase = ctxPtr->base; - ctxPtr->base = newBlock - ctxPtr->dictLimit; + ctxPtr->dictStart = ctxPtr->prefixStart; + ctxPtr->dictLimit += (U32)(ctxPtr->end - ctxPtr->prefixStart); + ctxPtr->prefixStart = newBlock; ctxPtr->end = newBlock; ctxPtr->nextToUpdate = ctxPtr->dictLimit; /* match referencing will resume from there */ @@ -1113,11 +1117,11 @@ LZ4_compressHC_continue_generic (LZ4_streamHC_t* LZ4_streamHCPtr, LZ4_streamHCPtr, src, *srcSizePtr, limit); assert(ctxPtr != NULL); /* auto-init if forgotten */ - if (ctxPtr->base == NULL) LZ4HC_init_internal (ctxPtr, (const BYTE*) src); + if (ctxPtr->prefixStart == NULL) LZ4HC_init_internal (ctxPtr, (const BYTE*) src); /* Check overflow */ - if ((size_t)(ctxPtr->end - ctxPtr->base) > 2 GB) { - size_t dictSize = (size_t)(ctxPtr->end - ctxPtr->base) - ctxPtr->dictLimit; + if ((size_t)(ctxPtr->end - ctxPtr->prefixStart) + ctxPtr->dictLimit > 2 GB) { + size_t dictSize = (size_t)(ctxPtr->end - ctxPtr->prefixStart); if (dictSize > 64 KB) dictSize = 64 KB; LZ4_loadDictHC(LZ4_streamHCPtr, (const char*)(ctxPtr->end) - dictSize, (int)dictSize); } @@ -1128,13 +1132,16 @@ LZ4_compressHC_continue_generic (LZ4_streamHC_t* LZ4_streamHCPtr, /* Check overlapping input/dictionary space */ { const BYTE* sourceEnd = (const BYTE*) src + *srcSizePtr; - const BYTE* const dictBegin = ctxPtr->dictBase + ctxPtr->lowLimit; - const BYTE* const dictEnd = ctxPtr->dictBase + ctxPtr->dictLimit; + const BYTE* const dictBegin = ctxPtr->dictStart; + const BYTE* const dictEnd = ctxPtr->dictStart + (ctxPtr->dictLimit - ctxPtr->lowLimit); if ((sourceEnd > dictBegin) && ((const BYTE*)src < dictEnd)) { if (sourceEnd > dictEnd) sourceEnd = dictEnd; - ctxPtr->lowLimit = (U32)(sourceEnd - ctxPtr->dictBase); - if (ctxPtr->dictLimit - ctxPtr->lowLimit < 4) ctxPtr->lowLimit = ctxPtr->dictLimit; - } } + ctxPtr->lowLimit += (U32)(sourceEnd - ctxPtr->dictStart); + ctxPtr->dictStart += (U32)(sourceEnd - ctxPtr->dictStart); + if (ctxPtr->dictLimit - ctxPtr->lowLimit < 4) { + ctxPtr->lowLimit = ctxPtr->dictLimit; + ctxPtr->dictStart = ctxPtr->prefixStart; + } } } return LZ4HC_compress_generic (ctxPtr, src, dst, srcSizePtr, dstCapacity, ctxPtr->compressionLevel, limit); } @@ -1162,7 +1169,7 @@ int LZ4_compress_HC_continue_destSize (LZ4_streamHC_t* LZ4_streamHCPtr, const ch int LZ4_saveDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, char* safeBuffer, int dictSize) { LZ4HC_CCtx_internal* const streamPtr = &LZ4_streamHCPtr->internal_donotuse; - int const prefixSize = (int)(streamPtr->end - (streamPtr->base + streamPtr->dictLimit)); + int const prefixSize = (int)(streamPtr->end - streamPtr->prefixStart); DEBUGLOG(5, "LZ4_saveDictHC(%p, %p, %d)", LZ4_streamHCPtr, safeBuffer, dictSize); assert(prefixSize >= 0); if (dictSize > 64 KB) dictSize = 64 KB; @@ -1171,11 +1178,12 @@ int LZ4_saveDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, char* safeBuffer, int dictS if (safeBuffer == NULL) assert(dictSize == 0); if (dictSize > 0) memmove(safeBuffer, streamPtr->end - dictSize, dictSize); - { U32 const endIndex = (U32)(streamPtr->end - streamPtr->base); + { U32 const endIndex = (U32)(streamPtr->end - streamPtr->prefixStart) + streamPtr->dictLimit; streamPtr->end = (const BYTE*)safeBuffer + dictSize; - streamPtr->base = streamPtr->end - endIndex; + streamPtr->prefixStart = streamPtr->end - dictSize; streamPtr->dictLimit = endIndex - (U32)dictSize; streamPtr->lowLimit = endIndex - (U32)dictSize; + streamPtr->dictStart = streamPtr->prefixStart; if (streamPtr->nextToUpdate < streamPtr->dictLimit) streamPtr->nextToUpdate = streamPtr->dictLimit; } @@ -1242,11 +1250,11 @@ int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* src, c char* LZ4_slideInputBufferHC(void* LZ4HC_Data) { - LZ4_streamHC_t *ctx = (LZ4_streamHC_t*)LZ4HC_Data; - const BYTE *bufferStart = ctx->internal_donotuse.base + ctx->internal_donotuse.lowLimit; + LZ4_streamHC_t* const ctx = (LZ4_streamHC_t*)LZ4HC_Data; + const BYTE* bufferStart = ctx->internal_donotuse.prefixStart - ctx->internal_donotuse.dictLimit + ctx->internal_donotuse.lowLimit; LZ4_resetStreamHC_fast(ctx, ctx->internal_donotuse.compressionLevel); /* avoid const char * -> char * conversion warning :( */ - return (char *)(uptrval)bufferStart; + return (char*)(uptrval)bufferStart; } diff --git a/lib/lz4hc.h b/lib/lz4hc.h index 61e228d..d2e5193 100644 --- a/lib/lz4hc.h +++ b/lib/lz4hc.h @@ -207,8 +207,8 @@ struct LZ4HC_CCtx_internal LZ4_u32 hashTable[LZ4HC_HASHTABLESIZE]; LZ4_u16 chainTable[LZ4HC_MAXD]; const LZ4_byte* end; /* next block here to continue on current prefix */ - const LZ4_byte* base; /* All index relative to this position */ - const LZ4_byte* dictBase; /* alternate base for extDict */ + const LZ4_byte* prefixStart; /* Indexes relative to this position */ + const LZ4_byte* dictStart; /* alternate reference for extDict */ LZ4_u32 dictLimit; /* below that point, need extDict */ LZ4_u32 lowLimit; /* below that point, no more dict */ LZ4_u32 nextToUpdate; /* index from which to continue dictionary update */ |