diff options
Diffstat (limited to 'lib/lz4hc.c')
| -rw-r--r-- | lib/lz4hc.c | 689 |
1 files changed, 446 insertions, 243 deletions
diff --git a/lib/lz4hc.c b/lib/lz4hc.c index e913ee7..77c9f43 100644 --- a/lib/lz4hc.c +++ b/lib/lz4hc.c @@ -53,7 +53,7 @@ #include "lz4hc.h" -/*=== Common LZ4 definitions ===*/ +/*=== Common definitions ===*/ #if defined(__GNUC__) # pragma GCC diagnostic ignored "-Wunused-function" #endif @@ -62,7 +62,13 @@ #endif #define LZ4_COMMONDEFS_ONLY +#ifndef LZ4_SRC_INCLUDED #include "lz4.c" /* LZ4_count, constants, mem */ +#endif + + +/*=== Enums ===*/ +typedef enum { noDictCtx, usingDictCtxHc } dictCtx_directive; /*=== Constants ===*/ @@ -76,25 +82,24 @@ #define HASH_FUNCTION(i) (((i) * 2654435761U) >> ((MINMATCH*8)-LZ4HC_HASH_LOG)) #define DELTANEXTMAXD(p) chainTable[(p) & LZ4HC_MAXD_MASK] /* flexible, LZ4HC_MAXD dependent */ #define DELTANEXTU16(table, pos) table[(U16)(pos)] /* faster */ +/* Make fields passed to, and updated by LZ4HC_encodeSequence explicit */ +#define UPDATABLE(ip, op, anchor) &ip, &op, &anchor static U32 LZ4HC_hashPtr(const void* ptr) { return HASH_FUNCTION(LZ4_read32(ptr)); } -/*=== Enums ===*/ -typedef enum { noDictCtx, usingDictCtx } dictCtx_directive; - /************************************** * HC Compression **************************************/ static void LZ4HC_clearTables (LZ4HC_CCtx_internal* hc4) { - MEM_INIT((void*)hc4->hashTable, 0, sizeof(hc4->hashTable)); + MEM_INIT(hc4->hashTable, 0, sizeof(hc4->hashTable)); MEM_INIT(hc4->chainTable, 0xFF, sizeof(hc4->chainTable)); } -static void LZ4HC_init (LZ4HC_CCtx_internal* hc4, const BYTE* start) +static void LZ4HC_init_internal (LZ4HC_CCtx_internal* hc4, const BYTE* start) { - uptrval startingOffset = hc4->end - hc4->base; + uptrval startingOffset = (uptrval)(hc4->end - hc4->base); if (startingOffset > 1 GB) { LZ4HC_clearTables(hc4); startingOffset = 0; @@ -121,7 +126,7 @@ LZ4_FORCE_INLINE void LZ4HC_Insert (LZ4HC_CCtx_internal* hc4, const BYTE* ip) while (idx < target) { U32 const h = LZ4HC_hashPtr(base+idx); size_t delta = idx - hashTable[h]; - if (delta>MAX_DISTANCE) delta = MAX_DISTANCE; + if (delta>LZ4_DISTANCE_MAX) delta = LZ4_DISTANCE_MAX; DELTANEXTU16(chainTable, idx) = (U16)delta; hashTable[h] = idx; idx++; @@ -147,13 +152,28 @@ int LZ4HC_countBack(const BYTE* const ip, const BYTE* const match, return back; } +#if defined(_MSC_VER) +# define LZ4HC_rotl32(x,r) _rotl(x,r) +#else +# define LZ4HC_rotl32(x,r) ((x << r) | (x >> (32 - r))) +#endif + + +static U32 LZ4HC_rotatePattern(size_t const rotate, U32 const pattern) +{ + size_t const bitsToRotate = (rotate & (sizeof(pattern) - 1)) << 3; + if (bitsToRotate == 0) return pattern; + return LZ4HC_rotl32(pattern, (int)bitsToRotate); +} + /* LZ4HC_countPattern() : * pattern32 must be a sample of repetitive pattern of length 1, 2 or 4 (but not 3!) */ static unsigned LZ4HC_countPattern(const BYTE* ip, const BYTE* const iEnd, U32 const pattern32) { const BYTE* const iStart = ip; - reg_t const pattern = (sizeof(pattern)==8) ? (reg_t)pattern32 + (((reg_t)pattern32) << 32) : pattern32; + reg_t const pattern = (sizeof(pattern)==8) ? + (reg_t)pattern32 + (((reg_t)pattern32) << (sizeof(pattern)*4)) : pattern32; while (likely(ip < iEnd-(sizeof(pattern)-1))) { reg_t const diff = LZ4_read_ARCH(ip) ^ pattern; @@ -199,6 +219,16 @@ LZ4HC_reverseCountPattern(const BYTE* ip, const BYTE* const iLow, U32 pattern) return (unsigned)(iStart - ip); } +/* LZ4HC_protectDictEnd() : + * Checks if the match is in the last 3 bytes of the dictionary, so reading the + * 4 byte MINMATCH would overflow. + * @returns true if the match index is okay. + */ +static int LZ4HC_protectDictEnd(U32 const dictLimit, U32 const matchIndex) +{ + return ((U32)((dictLimit - 1) - matchIndex) >= 3); +} + typedef enum { rep_untested, rep_not, rep_confirmed } repeat_state_e; typedef enum { favorCompressionRatio=0, favorDecompressionSpeed } HCfavor_e; @@ -224,14 +254,13 @@ LZ4HC_InsertAndGetWiderMatch ( const U32 dictLimit = hc4->dictLimit; const BYTE* const lowPrefixPtr = base + dictLimit; const U32 ipIndex = (U32)(ip - base); - const U32 lowestMatchIndex = (hc4->lowLimit + 64 KB > ipIndex) ? hc4->lowLimit : ipIndex - MAX_DISTANCE; + const U32 lowestMatchIndex = (hc4->lowLimit + (LZ4_DISTANCE_MAX + 1) > ipIndex) ? hc4->lowLimit : ipIndex - LZ4_DISTANCE_MAX; const BYTE* const dictBase = hc4->dictBase; int const lookBackLength = (int)(ip-iLowLimit); int nbAttempts = maxNbAttempts; - int matchChainPos = 0; + U32 matchChainPos = 0; U32 const pattern = LZ4_read32(ip); U32 matchIndex; - U32 dictMatchIndex; repeat_state_e repeat = rep_untested; size_t srcPatternLength = 0; @@ -242,7 +271,7 @@ LZ4HC_InsertAndGetWiderMatch ( DEBUGLOG(7, "First match at index %u / %u (lowestMatchIndex)", matchIndex, lowestMatchIndex); - while ((matchIndex>=lowestMatchIndex) && (nbAttempts)) { + while ((matchIndex>=lowestMatchIndex) && (nbAttempts>0)) { int matchLength=0; nbAttempts--; assert(matchIndex < ipIndex); @@ -256,7 +285,7 @@ LZ4HC_InsertAndGetWiderMatch ( 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; - matchLength = MINMATCH + LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit); + matchLength = MINMATCH + (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit); matchLength -= back; if (matchLength > longest) { longest = matchLength; @@ -270,7 +299,7 @@ LZ4HC_InsertAndGetWiderMatch ( int back = 0; const BYTE* vLimit = ip + (dictLimit - matchIndex); if (vLimit > iHighLimit) vLimit = iHighLimit; - matchLength = LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH; + matchLength = (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH; if ((ip+matchLength == vLimit) && (vLimit < iHighLimit)) matchLength += LZ4_count(ip+matchLength, lowPrefixPtr, iHighLimit); back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictStart) : 0; @@ -283,15 +312,22 @@ LZ4HC_InsertAndGetWiderMatch ( if (chainSwap && matchLength==longest) { /* better match => select a better chain */ assert(lookBackLength==0); /* search forward only */ - if (matchIndex + longest <= ipIndex) { + if (matchIndex + (U32)longest <= ipIndex) { + int const kTrigger = 4; U32 distanceToNextMatch = 1; + int const end = longest - MINMATCH + 1; + int step = 1; + int accel = 1 << kTrigger; int pos; - for (pos = 0; pos <= longest - MINMATCH; pos++) { - U32 const candidateDist = DELTANEXTU16(chainTable, matchIndex + pos); + for (pos = 0; pos < end; pos += step) { + U32 const candidateDist = DELTANEXTU16(chainTable, matchIndex + (U32)pos); + step = (accel++ >> kTrigger); if (candidateDist > distanceToNextMatch) { distanceToNextMatch = candidateDist; - matchChainPos = pos; - } } + matchChainPos = (U32)pos; + accel = 1 << kTrigger; + } + } if (distanceToNextMatch > 1) { if (distanceToNextMatch > matchIndex) break; /* avoid overflow */ matchIndex -= distanceToNextMatch; @@ -310,49 +346,78 @@ LZ4HC_InsertAndGetWiderMatch ( } else { repeat = rep_not; } } - if ( (repeat == rep_confirmed) - && (matchCandidateIdx >= dictLimit) ) { /* same segment only */ - const BYTE* const matchPtr = base + matchCandidateIdx; + if ( (repeat == rep_confirmed) && (matchCandidateIdx >= lowestMatchIndex) + && LZ4HC_protectDictEnd(dictLimit, matchCandidateIdx) ) { + const int extDict = matchCandidateIdx < dictLimit; + const BYTE* const matchPtr = (extDict ? dictBase : base) + matchCandidateIdx; if (LZ4_read32(matchPtr) == pattern) { /* good candidate */ - size_t const forwardPatternLength = LZ4HC_countPattern(matchPtr+sizeof(pattern), iHighLimit, pattern) + sizeof(pattern); - const BYTE* const lowestMatchPtr = (lowPrefixPtr + MAX_DISTANCE >= ip) ? lowPrefixPtr : ip - MAX_DISTANCE; - size_t const backLength = LZ4HC_reverseCountPattern(matchPtr, lowestMatchPtr, pattern); - size_t const currentSegmentLength = backLength + forwardPatternLength; - - if ( (currentSegmentLength >= srcPatternLength) /* current pattern segment large enough to contain full srcPatternLength */ - && (forwardPatternLength <= srcPatternLength) ) { /* haven't reached this position yet */ - matchIndex = matchCandidateIdx + (U32)forwardPatternLength - (U32)srcPatternLength; /* best position, full pattern, might be followed by more match */ - } else { - matchIndex = matchCandidateIdx - (U32)backLength; /* farthest position in current segment, will find a match of length currentSegmentLength + maybe some back */ - if (lookBackLength==0) { /* no back possible */ - size_t const maxML = MIN(currentSegmentLength, srcPatternLength); - if ((size_t)longest < maxML) { - assert(base + matchIndex < ip); - if (ip - (base+matchIndex) > MAX_DISTANCE) break; - assert(maxML < 2 GB); - longest = (int)maxML; - *matchpos = base + matchIndex; /* virtual pos, relative to ip, to retrieve offset */ - *startpos = ip; + const BYTE* const dictStart = dictBase + hc4->lowLimit; + const BYTE* const iLimit = extDict ? dictBase + dictLimit : 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); + } + { const BYTE* const lowestMatchPtr = extDict ? dictStart : lowPrefixPtr; + size_t backLength = LZ4HC_reverseCountPattern(matchPtr, lowestMatchPtr, pattern); + size_t currentSegmentLength; + if (!extDict && matchPtr - backLength == lowPrefixPtr && hc4->lowLimit < dictLimit) { + U32 const rotatedPattern = LZ4HC_rotatePattern((U32)(-(int)backLength), pattern); + backLength += LZ4HC_reverseCountPattern(dictBase + dictLimit, dictStart, rotatedPattern); + } + /* Limit backLength not go further than lowestMatchIndex */ + backLength = matchCandidateIdx - MAX(matchCandidateIdx - (U32)backLength, lowestMatchIndex); + assert(matchCandidateIdx - backLength >= lowestMatchIndex); + currentSegmentLength = backLength + forwardPatternLength; + /* Adjust to end of pattern if the source pattern fits, otherwise the beginning of the pattern */ + 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)) + matchIndex = newMatchIndex; + else { + /* Can only happen if started in the prefix */ + assert(newMatchIndex >= dictLimit - 3 && newMatchIndex < dictLimit && !extDict); + matchIndex = dictLimit; } - { U32 const distToNextPattern = DELTANEXTU16(chainTable, matchIndex); - if (distToNextPattern > matchIndex) break; /* avoid overflow */ - matchIndex -= distToNextPattern; - } } } + } 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; + } 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(maxML < 2 GB); + longest = (int)maxML; + *matchpos = base + matchIndex; /* virtual pos, relative to ip, to retrieve offset */ + *startpos = ip; + } + { U32 const distToNextPattern = DELTANEXTU16(chainTable, matchIndex); + if (distToNextPattern > matchIndex) break; /* avoid overflow */ + matchIndex -= distToNextPattern; + } } } } } continue; } } } } /* PA optimization */ /* follow current chain */ - matchIndex -= DELTANEXTU16(chainTable, matchIndex+matchChainPos); + matchIndex -= DELTANEXTU16(chainTable, matchIndex + matchChainPos); } /* while ((matchIndex>=lowestMatchIndex) && (nbAttempts)) */ - if (dict == usingDictCtx && nbAttempts && ipIndex - lowestMatchIndex < MAX_DISTANCE) { - size_t const dictEndOffset = dictCtx->end - dictCtx->base; + if ( dict == usingDictCtxHc + && nbAttempts > 0 + && ipIndex - lowestMatchIndex < LZ4_DISTANCE_MAX) { + size_t const dictEndOffset = (size_t)(dictCtx->end - dictCtx->base); + U32 dictMatchIndex = dictCtx->hashTable[LZ4HC_hashPtr(ip)]; assert(dictEndOffset <= 1 GB); - dictMatchIndex = dictCtx->hashTable[LZ4HC_hashPtr(ip)]; matchIndex = dictMatchIndex + lowestMatchIndex - (U32)dictEndOffset; - while (ipIndex - matchIndex <= MAX_DISTANCE && nbAttempts--) { + while (ipIndex - matchIndex <= LZ4_DISTANCE_MAX && nbAttempts--) { const BYTE* const matchPtr = dictCtx->base + dictMatchIndex; if (LZ4_read32(matchPtr) == pattern) { @@ -360,22 +425,19 @@ LZ4HC_InsertAndGetWiderMatch ( int back = 0; const BYTE* vLimit = ip + (dictEndOffset - dictMatchIndex); if (vLimit > iHighLimit) vLimit = iHighLimit; - mlt = LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH; + mlt = (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH; back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictCtx->base + dictCtx->dictLimit) : 0; mlt -= back; if (mlt > longest) { longest = mlt; *matchpos = base + matchIndex + back; *startpos = ip + back; - } - } + } } { U32 const nextOffset = DELTANEXTU16(dictCtx->chainTable, dictMatchIndex); dictMatchIndex -= nextOffset; matchIndex -= nextOffset; - } - } - } + } } } return longest; } @@ -395,86 +457,94 @@ int LZ4HC_InsertAndFindBestMatch(LZ4HC_CCtx_internal* const hc4, /* Index tabl return LZ4HC_InsertAndGetWiderMatch(hc4, ip, ip, iLimit, MINMATCH-1, matchpos, &uselessPtr, maxNbAttempts, patternAnalysis, 0 /*chainSwap*/, dict, favorCompressionRatio); } - - -typedef enum { - noLimit = 0, - limitedOutput = 1, - limitedDestSize = 2, -} limitedOutput_directive; - /* LZ4HC_encodeSequence() : * @return : 0 if ok, * 1 if buffer issue detected */ LZ4_FORCE_INLINE int LZ4HC_encodeSequence ( - const BYTE** ip, - BYTE** op, - const BYTE** anchor, + const BYTE** _ip, + BYTE** _op, + const BYTE** _anchor, int matchLength, const BYTE* const match, limitedOutput_directive limit, BYTE* oend) { +#define ip (*_ip) +#define op (*_op) +#define anchor (*_anchor) + size_t length; - BYTE* const token = (*op)++; + BYTE* const token = op++; #if defined(LZ4_DEBUG) && (LZ4_DEBUG >= 6) static const BYTE* start = NULL; static U32 totalCost = 0; - U32 const pos = (start==NULL) ? 0 : (U32)(*anchor - start); - U32 const ll = (U32)(*ip - *anchor); + U32 const pos = (start==NULL) ? 0 : (U32)(anchor - start); + U32 const ll = (U32)(ip - anchor); U32 const llAdd = (ll>=15) ? ((ll-15) / 255) + 1 : 0; U32 const mlAdd = (matchLength>=19) ? ((matchLength-19) / 255) + 1 : 0; U32 const cost = 1 + llAdd + ll + 2 + mlAdd; - if (start==NULL) start = *anchor; /* only works for single segment */ + if (start==NULL) start = anchor; /* only works for single segment */ /* g_debuglog_enable = (pos >= 2228) & (pos <= 2262); */ - DEBUGLOG(6, "pos:%7u -- literals:%3u, match:%4i, offset:%5u, cost:%3u + %u", + DEBUGLOG(6, "pos:%7u -- literals:%4u, match:%4i, offset:%5u, cost:%4u + %5u", pos, - (U32)(*ip - *anchor), matchLength, (U32)(*ip-match), + (U32)(ip - anchor), matchLength, (U32)(ip-match), cost, totalCost); totalCost += cost; #endif /* Encode Literal length */ - length = (size_t)(*ip - *anchor); - if ((limit) && ((*op + (length >> 8) + length + (2 + 1 + LASTLITERALS)) > oend)) return 1; /* Check output limit */ + length = (size_t)(ip - anchor); + LZ4_STATIC_ASSERT(notLimited == 0); + /* Check output limit */ + if (limit && ((op + (length / 255) + length + (2 + 1 + LASTLITERALS)) > oend)) { + DEBUGLOG(6, "Not enough room to write %i literals (%i bytes remaining)", + (int)length, (int)(oend - op)); + return 1; + } if (length >= RUN_MASK) { size_t len = length - RUN_MASK; *token = (RUN_MASK << ML_BITS); - for(; len >= 255 ; len -= 255) *(*op)++ = 255; - *(*op)++ = (BYTE)len; + for(; len >= 255 ; len -= 255) *op++ = 255; + *op++ = (BYTE)len; } else { *token = (BYTE)(length << ML_BITS); } /* Copy Literals */ - LZ4_wildCopy(*op, *anchor, (*op) + length); - *op += length; + LZ4_wildCopy8(op, anchor, op + length); + op += length; /* Encode Offset */ - assert( (*ip - match) <= MAX_DISTANCE ); /* note : consider providing offset as a value, rather than as a pointer difference */ - LZ4_writeLE16(*op, (U16)(*ip-match)); *op += 2; + assert( (ip - match) <= LZ4_DISTANCE_MAX ); /* note : consider providing offset as a value, rather than as a pointer difference */ + LZ4_writeLE16(op, (U16)(ip - match)); op += 2; /* Encode MatchLength */ assert(matchLength >= MINMATCH); - length = (size_t)(matchLength - MINMATCH); - if ((limit) && (*op + (length >> 8) + (1 + LASTLITERALS) > oend)) return 1; /* Check output limit */ + length = (size_t)matchLength - MINMATCH; + if (limit && (op + (length / 255) + (1 + LASTLITERALS) > oend)) { + DEBUGLOG(6, "Not enough room to write match length"); + return 1; /* Check output limit */ + } if (length >= ML_MASK) { *token += ML_MASK; length -= ML_MASK; - for(; length >= 510 ; length -= 510) { *(*op)++ = 255; *(*op)++ = 255; } - if (length >= 255) { length -= 255; *(*op)++ = 255; } - *(*op)++ = (BYTE)length; + for(; length >= 510 ; length -= 510) { *op++ = 255; *op++ = 255; } + if (length >= 255) { length -= 255; *op++ = 255; } + *op++ = (BYTE)length; } else { *token += (BYTE)(length); } /* Prepare next loop */ - *ip += matchLength; - *anchor = *ip; + ip += matchLength; + anchor = ip; return 0; } +#undef ip +#undef op +#undef anchor LZ4_FORCE_INLINE int LZ4HC_compress_hashChain ( LZ4HC_CCtx_internal* const ctx, @@ -482,7 +552,7 @@ LZ4_FORCE_INLINE int LZ4HC_compress_hashChain ( char* const dest, int* srcSizePtr, int const maxOutputSize, - unsigned maxNbAttempts, + int maxNbAttempts, const limitedOutput_directive limit, const dictCtx_directive dict ) @@ -511,12 +581,12 @@ LZ4_FORCE_INLINE int LZ4HC_compress_hashChain ( /* init */ *srcSizePtr = 0; - if (limit == limitedDestSize) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */ - if (inputSize < LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */ + if (limit == fillOutput) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */ + if (inputSize < LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */ /* Main Loop */ while (ip <= mflimit) { - ml = LZ4HC_InsertAndFindBestMatch (ctx, ip, matchlimit, &ref, maxNbAttempts, patternAnalysis, dict); + ml = LZ4HC_InsertAndFindBestMatch(ctx, ip, matchlimit, &ref, maxNbAttempts, patternAnalysis, dict); if (ml<MINMATCH) { ip++; continue; } /* saved, in case we would skip too much */ @@ -533,7 +603,7 @@ _Search2: if (ml2 == ml) { /* No better match => encode ML1 */ optr = op; - if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow; + if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow; continue; } @@ -581,10 +651,14 @@ _Search3: if (start2 < ip+ml) ml = (int)(start2 - ip); /* Now, encode 2 sequences */ optr = op; - if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow; + if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow; ip = start2; optr = op; - if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml2, ref2, limit, oend)) goto _dest_overflow; + if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml2, ref2, limit, oend)) { + ml = ml2; + ref = ref2; + goto _dest_overflow; + } continue; } @@ -603,7 +677,7 @@ _Search3: } optr = op; - if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow; + if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow; ip = start3; ref = ref3; ml = ml3; @@ -641,7 +715,7 @@ _Search3: } } optr = op; - if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow; + if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow; /* ML2 becomes ML1 */ ip = start2; ref = ref2; ml = ml2; @@ -656,17 +730,18 @@ _Search3: _last_literals: /* Encode Last Literals */ { size_t lastRunSize = (size_t)(iend - anchor); /* literals */ - size_t litLength = (lastRunSize + 255 - RUN_MASK) / 255; - size_t const totalSize = 1 + litLength + lastRunSize; - if (limit == limitedDestSize) oend += LASTLITERALS; /* restore correct value */ + size_t llAdd = (lastRunSize + 255 - RUN_MASK) / 255; + size_t const totalSize = 1 + llAdd + lastRunSize; + if (limit == fillOutput) oend += LASTLITERALS; /* restore correct value */ if (limit && (op + totalSize > oend)) { - if (limit == limitedOutput) return 0; /* Check output limit */ + if (limit == limitedOutput) return 0; /* adapt lastRunSize to fill 'dest' */ - lastRunSize = (size_t)(oend - op) - 1; - litLength = (lastRunSize + 255 - RUN_MASK) / 255; - lastRunSize -= litLength; + lastRunSize = (size_t)(oend - op) - 1 /*token*/; + llAdd = (lastRunSize + 256 - RUN_MASK) / 256; + lastRunSize -= llAdd; } - ip = anchor + lastRunSize; + DEBUGLOG(6, "Final literal run : %i literals", (int)lastRunSize); + ip = anchor + lastRunSize; /* can be != iend if limit==fillOutput */ if (lastRunSize >= RUN_MASK) { size_t accumulator = lastRunSize - RUN_MASK; @@ -685,10 +760,26 @@ _last_literals: return (int) (((char*)op)-dest); _dest_overflow: - if (limit == limitedDestSize) { + if (limit == fillOutput) { + /* Assumption : ip, anchor, ml and ref must be set correctly */ + size_t const ll = (size_t)(ip - anchor); + size_t const ll_addbytes = (ll + 240) / 255; + size_t const ll_totalCost = 1 + ll_addbytes + ll; + BYTE* const maxLitPos = oend - 3; /* 2 for offset, 1 for token */ + DEBUGLOG(6, "Last sequence overflowing"); op = optr; /* restore correct out pointer */ + if (op + ll_totalCost <= maxLitPos) { + /* ll validated; now adjust match length */ + size_t const bytesLeftForMl = (size_t)(maxLitPos - (op+ll_totalCost)); + size_t const maxMlSize = MINMATCH + (ML_MASK-1) + (bytesLeftForMl * 255); + assert(maxMlSize < INT_MAX); assert(ml >= 0); + if ((size_t)ml > maxMlSize) ml = (int)maxMlSize; + if ((oend + LASTLITERALS) - (op + ll_totalCost + 2) - 1 + ml >= MFLIMIT) { + LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, notLimited, oend); + } } goto _last_literals; } + /* compression failed */ return 0; } @@ -699,7 +790,7 @@ static int LZ4HC_compress_optimal( LZ4HC_CCtx_internal* ctx, int const nbSearches, size_t sufficient_len, const limitedOutput_directive limit, int const fullUpdate, const dictCtx_directive dict, - HCfavor_e favorDecSpeed); + const HCfavor_e favorDecSpeed); LZ4_FORCE_INLINE int LZ4HC_compress_generic_internal ( @@ -716,7 +807,7 @@ LZ4_FORCE_INLINE int LZ4HC_compress_generic_internal ( typedef enum { lz4hc, lz4opt } lz4hc_strat_e; typedef struct { lz4hc_strat_e strat; - U32 nbSearches; + int nbSearches; U32 targetLength; } cParams_t; static const cParams_t clTable[LZ4HC_CLEVEL_MAX+1] = { @@ -735,56 +826,65 @@ LZ4_FORCE_INLINE int LZ4HC_compress_generic_internal ( { lz4opt,16384,LZ4_OPT_NUM }, /* 12==LZ4HC_CLEVEL_MAX */ }; - DEBUGLOG(4, "LZ4HC_compress_generic(%p, %p, %d)", ctx, src, *srcSizePtr); + DEBUGLOG(4, "LZ4HC_compress_generic(ctx=%p, src=%p, srcSize=%d, limit=%d)", + ctx, src, *srcSizePtr, limit); - if (limit == limitedDestSize && dstCapacity < 1) return 0; /* Impossible to store anything */ - if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size (too large or negative) */ + if (limit == fillOutput && dstCapacity < 1) return 0; /* Impossible to store anything */ + if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size (too large or negative) */ ctx->end += *srcSizePtr; if (cLevel < 1) cLevel = LZ4HC_CLEVEL_DEFAULT; /* note : convention is different from lz4frame, maybe something to review */ cLevel = MIN(LZ4HC_CLEVEL_MAX, cLevel); { cParams_t const cParam = clTable[cLevel]; HCfavor_e const favor = ctx->favorDecSpeed ? favorDecompressionSpeed : favorCompressionRatio; - if (cParam.strat == lz4hc) - return LZ4HC_compress_hashChain(ctx, + int result; + + if (cParam.strat == lz4hc) { + result = LZ4HC_compress_hashChain(ctx, src, dst, srcSizePtr, dstCapacity, cParam.nbSearches, limit, dict); - assert(cParam.strat == lz4opt); - return LZ4HC_compress_optimal(ctx, - src, dst, srcSizePtr, dstCapacity, - cParam.nbSearches, cParam.targetLength, limit, - cLevel == LZ4HC_CLEVEL_MAX, /* ultra mode */ - dict, favor); + } else { + assert(cParam.strat == lz4opt); + result = LZ4HC_compress_optimal(ctx, + src, dst, srcSizePtr, dstCapacity, + cParam.nbSearches, cParam.targetLength, limit, + cLevel == LZ4HC_CLEVEL_MAX, /* ultra mode */ + dict, favor); + } + if (result <= 0) ctx->dirty = 1; + return result; } } static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* ctxPtr, const BYTE* newBlock); -static int LZ4HC_compress_generic_noDictCtx ( - LZ4HC_CCtx_internal* const ctx, - const char* const src, - char* const dst, - int* const srcSizePtr, - int const dstCapacity, - int cLevel, - limitedOutput_directive limit - ) +static int +LZ4HC_compress_generic_noDictCtx ( + LZ4HC_CCtx_internal* const ctx, + const char* const src, + char* const dst, + int* const srcSizePtr, + int const dstCapacity, + int cLevel, + limitedOutput_directive limit + ) { assert(ctx->dictCtx == NULL); return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, noDictCtx); } -static int LZ4HC_compress_generic_dictCtx ( - LZ4HC_CCtx_internal* const ctx, - const char* const src, - char* const dst, - int* const srcSizePtr, - int const dstCapacity, - int cLevel, - limitedOutput_directive limit - ) +static int +LZ4HC_compress_generic_dictCtx ( + LZ4HC_CCtx_internal* const ctx, + const char* const src, + char* const dst, + int* const srcSizePtr, + int const dstCapacity, + int cLevel, + limitedOutput_directive limit + ) { - const size_t position = ctx->end - ctx->base - ctx->lowLimit; + const size_t position = (size_t)(ctx->end - ctx->base) - ctx->lowLimit; assert(ctx->dictCtx != NULL); if (position >= 64 KB) { ctx->dictCtx = NULL; @@ -795,19 +895,20 @@ static int LZ4HC_compress_generic_dictCtx ( ctx->compressionLevel = (short)cLevel; return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit); } else { - return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, usingDictCtx); + return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, usingDictCtxHc); } } -static int LZ4HC_compress_generic ( - LZ4HC_CCtx_internal* const ctx, - const char* const src, - char* const dst, - int* const srcSizePtr, - int const dstCapacity, - int cLevel, - limitedOutput_directive limit - ) +static int +LZ4HC_compress_generic ( + LZ4HC_CCtx_internal* const ctx, + const char* const src, + char* const dst, + int* const srcSizePtr, + int const dstCapacity, + int cLevel, + limitedOutput_directive limit + ) { if (ctx->dictCtx == NULL) { return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit); @@ -817,24 +918,36 @@ static int LZ4HC_compress_generic ( } -int LZ4_sizeofStateHC(void) { return sizeof(LZ4_streamHC_t); } +int LZ4_sizeofStateHC(void) { return (int)sizeof(LZ4_streamHC_t); } + +static size_t LZ4_streamHC_t_alignment(void) +{ +#if LZ4_ALIGN_TEST + typedef struct { char c; LZ4_streamHC_t t; } t_a; + return sizeof(t_a) - sizeof(LZ4_streamHC_t); +#else + return 1; /* effectively disabled */ +#endif +} +/* state is presumed correctly initialized, + * in which case its size and alignment have already been validate */ int LZ4_compress_HC_extStateHC_fastReset (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel) { LZ4HC_CCtx_internal* const ctx = &((LZ4_streamHC_t*)state)->internal_donotuse; - if (((size_t)(state)&(sizeof(void*)-1)) != 0) return 0; /* Error : state is not aligned for pointers (32 or 64 bits) */ + if (!LZ4_isAligned(state, LZ4_streamHC_t_alignment())) return 0; LZ4_resetStreamHC_fast((LZ4_streamHC_t*)state, compressionLevel); - LZ4HC_init (ctx, (const BYTE*)src); + LZ4HC_init_internal (ctx, (const BYTE*)src); if (dstCapacity < LZ4_compressBound(srcSize)) return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, limitedOutput); else - return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, noLimit); + return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, notLimited); } int LZ4_compress_HC_extStateHC (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel) { - if (((size_t)(state)&(sizeof(void*)-1)) != 0) return 0; /* Error : state is not aligned for pointers (32 or 64 bits) */ - LZ4_resetStreamHC ((LZ4_streamHC_t*)state, compressionLevel); + LZ4_streamHC_t* const ctx = LZ4_initStreamHC(state, sizeof(*ctx)); + if (ctx==NULL) return 0; /* init failure */ return LZ4_compress_HC_extStateHC_fastReset(state, src, dst, srcSize, dstCapacity, compressionLevel); } @@ -848,19 +961,19 @@ int LZ4_compress_HC(const char* src, char* dst, int srcSize, int dstCapacity, in #endif int const cSize = LZ4_compress_HC_extStateHC(statePtr, src, dst, srcSize, dstCapacity, compressionLevel); #if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1 - free(statePtr); + FREEMEM(statePtr); #endif return cSize; } -/* LZ4_compress_HC_destSize() : - * only compatible with regular HC parser */ -int LZ4_compress_HC_destSize(void* LZ4HC_Data, const char* source, char* dest, int* sourceSizePtr, int targetDestSize, int cLevel) +/* state is presumed sized correctly (>= sizeof(LZ4_streamHC_t)) */ +int LZ4_compress_HC_destSize(void* state, const char* source, char* dest, int* sourceSizePtr, int targetDestSize, int cLevel) { - LZ4HC_CCtx_internal* const ctx = &((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse; - LZ4_resetStreamHC((LZ4_streamHC_t*)LZ4HC_Data, cLevel); - LZ4HC_init(ctx, (const BYTE*) source); - return LZ4HC_compress_generic(ctx, source, dest, sourceSizePtr, targetDestSize, cLevel, limitedDestSize); + LZ4_streamHC_t* const ctx = LZ4_initStreamHC(state, sizeof(*ctx)); + if (ctx==NULL) return 0; /* init failure */ + LZ4HC_init_internal(&ctx->internal_donotuse, (const BYTE*) source); + LZ4_setCompressionLevel(ctx, cLevel); + return LZ4HC_compress_generic(&ctx->internal_donotuse, source, dest, sourceSizePtr, targetDestSize, cLevel, fillOutput); } @@ -869,44 +982,65 @@ int LZ4_compress_HC_destSize(void* LZ4HC_Data, const char* source, char* dest, i * Streaming Functions **************************************/ /* allocation */ -LZ4_streamHC_t* LZ4_createStreamHC(void) { - LZ4_streamHC_t* const LZ4_streamHCPtr = (LZ4_streamHC_t*)ALLOC(sizeof(LZ4_streamHC_t)); - if (LZ4_streamHCPtr==NULL) return NULL; - LZ4_resetStreamHC(LZ4_streamHCPtr, LZ4HC_CLEVEL_DEFAULT); - return LZ4_streamHCPtr; +LZ4_streamHC_t* LZ4_createStreamHC(void) +{ + LZ4_streamHC_t* const state = + (LZ4_streamHC_t*)ALLOC_AND_ZERO(sizeof(LZ4_streamHC_t)); + if (state == NULL) return NULL; + LZ4_setCompressionLevel(state, LZ4HC_CLEVEL_DEFAULT); + return state; } -int LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr) { +int LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr) +{ DEBUGLOG(4, "LZ4_freeStreamHC(%p)", LZ4_streamHCPtr); if (!LZ4_streamHCPtr) return 0; /* support free on NULL */ - free(LZ4_streamHCPtr); + FREEMEM(LZ4_streamHCPtr); return 0; } -/* initialization */ +LZ4_streamHC_t* LZ4_initStreamHC (void* buffer, size_t size) +{ + LZ4_streamHC_t* const LZ4_streamHCPtr = (LZ4_streamHC_t*)buffer; + /* if compilation fails here, LZ4_STREAMHCSIZE must be increased */ + LZ4_STATIC_ASSERT(sizeof(LZ4HC_CCtx_internal) <= LZ4_STREAMHCSIZE); + DEBUGLOG(4, "LZ4_initStreamHC(%p, %u)", buffer, (unsigned)size); + /* check conditions */ + if (buffer == NULL) return NULL; + if (size < sizeof(LZ4_streamHC_t)) return NULL; + if (!LZ4_isAligned(buffer, LZ4_streamHC_t_alignment())) return NULL; + /* init */ + { LZ4HC_CCtx_internal* const hcstate = &(LZ4_streamHCPtr->internal_donotuse); + MEM_INIT(hcstate, 0, sizeof(*hcstate)); } + LZ4_setCompressionLevel(LZ4_streamHCPtr, LZ4HC_CLEVEL_DEFAULT); + return LZ4_streamHCPtr; +} + +/* just a stub */ void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel) { - LZ4_STATIC_ASSERT(sizeof(LZ4HC_CCtx_internal) <= sizeof(size_t) * LZ4_STREAMHCSIZE_SIZET); /* if compilation fails here, LZ4_STREAMHCSIZE must be increased */ - DEBUGLOG(4, "LZ4_resetStreamHC(%p, %d)", LZ4_streamHCPtr, compressionLevel); - LZ4_streamHCPtr->internal_donotuse.end = (const BYTE *)(ptrdiff_t)-1; - LZ4_streamHCPtr->internal_donotuse.base = NULL; - LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL; - LZ4_streamHCPtr->internal_donotuse.favorDecSpeed = 0; + LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr)); LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel); } void LZ4_resetStreamHC_fast (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel) { DEBUGLOG(4, "LZ4_resetStreamHC_fast(%p, %d)", LZ4_streamHCPtr, compressionLevel); - LZ4_streamHCPtr->internal_donotuse.end -= (uptrval)LZ4_streamHCPtr->internal_donotuse.base; - LZ4_streamHCPtr->internal_donotuse.base = NULL; - LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL; + if (LZ4_streamHCPtr->internal_donotuse.dirty) { + LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr)); + } else { + /* preserve end - base : can trigger clearTable's threshold */ + LZ4_streamHCPtr->internal_donotuse.end -= (uptrval)LZ4_streamHCPtr->internal_donotuse.base; + LZ4_streamHCPtr->internal_donotuse.base = NULL; + LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL; + } LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel); } void LZ4_setCompressionLevel(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel) { + DEBUGLOG(5, "LZ4_setCompressionLevel(%p, %d)", LZ4_streamHCPtr, compressionLevel); if (compressionLevel < 1) compressionLevel = LZ4HC_CLEVEL_DEFAULT; if (compressionLevel > LZ4HC_CLEVEL_MAX) compressionLevel = LZ4HC_CLEVEL_MAX; LZ4_streamHCPtr->internal_donotuse.compressionLevel = (short)compressionLevel; @@ -917,16 +1051,24 @@ void LZ4_favorDecompressionSpeed(LZ4_streamHC_t* LZ4_streamHCPtr, int favor) LZ4_streamHCPtr->internal_donotuse.favorDecSpeed = (favor!=0); } -int LZ4_loadDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, const char* dictionary, int dictSize) +/* LZ4_loadDictHC() : + * LZ4_streamHCPtr is presumed properly initialized */ +int LZ4_loadDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, + const char* dictionary, int dictSize) { LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse; - DEBUGLOG(4, "LZ4_loadDictHC(%p, %p, %d)", LZ4_streamHCPtr, dictionary, dictSize); + DEBUGLOG(4, "LZ4_loadDictHC(ctx:%p, dict:%p, dictSize:%d)", LZ4_streamHCPtr, dictionary, dictSize); + assert(LZ4_streamHCPtr != NULL); if (dictSize > 64 KB) { - dictionary += dictSize - 64 KB; + dictionary += (size_t)dictSize - 64 KB; dictSize = 64 KB; } - LZ4_resetStreamHC(LZ4_streamHCPtr, ctxPtr->compressionLevel); - LZ4HC_init (ctxPtr, (const BYTE*)dictionary); + /* need a full initialization, there are bad side-effects when using resetFast() */ + { int const cLevel = ctxPtr->compressionLevel; + LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr)); + LZ4_setCompressionLevel(LZ4_streamHCPtr, cLevel); + } + LZ4HC_init_internal (ctxPtr, (const BYTE*)dictionary); ctxPtr->end = (const BYTE*)dictionary + dictSize; if (dictSize >= 4) LZ4HC_Insert (ctxPtr, ctxPtr->end-3); return dictSize; @@ -951,17 +1093,23 @@ static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* ctxPtr, const BYTE* newBl ctxPtr->base = newBlock - ctxPtr->dictLimit; ctxPtr->end = newBlock; ctxPtr->nextToUpdate = ctxPtr->dictLimit; /* match referencing will resume from there */ + + /* cannot reference an extDict and a dictCtx at the same time */ + ctxPtr->dictCtx = NULL; } -static int LZ4_compressHC_continue_generic (LZ4_streamHC_t* LZ4_streamHCPtr, - const char* src, char* dst, - int* srcSizePtr, int dstCapacity, - limitedOutput_directive limit) +static int +LZ4_compressHC_continue_generic (LZ4_streamHC_t* LZ4_streamHCPtr, + const char* src, char* dst, + int* srcSizePtr, int dstCapacity, + limitedOutput_directive limit) { LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse; - DEBUGLOG(4, "LZ4_compressHC_continue_generic(%p, %p, %d)", LZ4_streamHCPtr, src, *srcSizePtr); + DEBUGLOG(5, "LZ4_compressHC_continue_generic(ctx=%p, src=%p, srcSize=%d, limit=%d)", + LZ4_streamHCPtr, src, *srcSizePtr, limit); + assert(ctxPtr != NULL); /* auto-init if forgotten */ - if (ctxPtr->base == NULL) LZ4HC_init (ctxPtr, (const BYTE*) src); + if (ctxPtr->base == NULL) LZ4HC_init_internal (ctxPtr, (const BYTE*) src); /* Check overflow */ if ((size_t)(ctxPtr->end - ctxPtr->base) > 2 GB) { @@ -971,7 +1119,8 @@ static int LZ4_compressHC_continue_generic (LZ4_streamHC_t* LZ4_streamHCPtr, } /* Check if blocks follow each other */ - if ((const BYTE*)src != ctxPtr->end) LZ4HC_setExternalDict(ctxPtr, (const BYTE*)src); + if ((const BYTE*)src != ctxPtr->end) + LZ4HC_setExternalDict(ctxPtr, (const BYTE*)src); /* Check overlapping input/dictionary space */ { const BYTE* sourceEnd = (const BYTE*) src + *srcSizePtr; @@ -981,8 +1130,7 @@ static int LZ4_compressHC_continue_generic (LZ4_streamHC_t* LZ4_streamHCPtr, if (sourceEnd > dictEnd) sourceEnd = dictEnd; ctxPtr->lowLimit = (U32)(sourceEnd - ctxPtr->dictBase); if (ctxPtr->dictLimit - ctxPtr->lowLimit < 4) ctxPtr->lowLimit = ctxPtr->dictLimit; - } - } + } } return LZ4HC_compress_generic (ctxPtr, src, dst, srcSizePtr, dstCapacity, ctxPtr->compressionLevel, limit); } @@ -992,43 +1140,52 @@ int LZ4_compress_HC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* src, if (dstCapacity < LZ4_compressBound(srcSize)) return LZ4_compressHC_continue_generic (LZ4_streamHCPtr, src, dst, &srcSize, dstCapacity, limitedOutput); else - return LZ4_compressHC_continue_generic (LZ4_streamHCPtr, src, dst, &srcSize, dstCapacity, noLimit); + return LZ4_compressHC_continue_generic (LZ4_streamHCPtr, src, dst, &srcSize, dstCapacity, notLimited); } int LZ4_compress_HC_continue_destSize (LZ4_streamHC_t* LZ4_streamHCPtr, const char* src, char* dst, int* srcSizePtr, int targetDestSize) { - return LZ4_compressHC_continue_generic(LZ4_streamHCPtr, src, dst, srcSizePtr, targetDestSize, limitedDestSize); + return LZ4_compressHC_continue_generic(LZ4_streamHCPtr, src, dst, srcSizePtr, targetDestSize, fillOutput); } -/* dictionary saving */ - +/* LZ4_saveDictHC : + * save history content + * into a user-provided buffer + * which is then used to continue compression + */ 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)); - DEBUGLOG(4, "LZ4_saveDictHC(%p, %p, %d)", LZ4_streamHCPtr, safeBuffer, dictSize); + DEBUGLOG(5, "LZ4_saveDictHC(%p, %p, %d)", LZ4_streamHCPtr, safeBuffer, dictSize); + assert(prefixSize >= 0); if (dictSize > 64 KB) dictSize = 64 KB; if (dictSize < 4) dictSize = 0; if (dictSize > prefixSize) dictSize = prefixSize; - memmove(safeBuffer, streamPtr->end - dictSize, dictSize); + if (safeBuffer == NULL) assert(dictSize == 0); + if (dictSize > 0) + memmove(safeBuffer, streamPtr->end - dictSize, dictSize); { U32 const endIndex = (U32)(streamPtr->end - streamPtr->base); streamPtr->end = (const BYTE*)safeBuffer + dictSize; streamPtr->base = streamPtr->end - endIndex; - streamPtr->dictLimit = endIndex - dictSize; - streamPtr->lowLimit = endIndex - dictSize; - if (streamPtr->nextToUpdate < streamPtr->dictLimit) streamPtr->nextToUpdate = streamPtr->dictLimit; + streamPtr->dictLimit = endIndex - (U32)dictSize; + streamPtr->lowLimit = endIndex - (U32)dictSize; + if (streamPtr->nextToUpdate < streamPtr->dictLimit) + streamPtr->nextToUpdate = streamPtr->dictLimit; } return dictSize; } -/*********************************** +/*************************************************** * Deprecated Functions -***********************************/ +***************************************************/ + /* These functions currently generate deprecation warnings */ -/* Deprecated compression functions */ + +/* Wrappers for deprecated compression functions */ int LZ4_compressHC(const char* src, char* dst, int srcSize) { return LZ4_compress_HC (src, dst, srcSize, LZ4_compressBound(srcSize), 0); } int LZ4_compressHC_limitedOutput(const char* src, char* dst, int srcSize, int maxDstSize) { return LZ4_compress_HC(src, dst, srcSize, maxDstSize, 0); } int LZ4_compressHC2(const char* src, char* dst, int srcSize, int cLevel) { return LZ4_compress_HC (src, dst, srcSize, LZ4_compressBound(srcSize), cLevel); } @@ -1044,25 +1201,26 @@ int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* ctx, const char* src, /* Deprecated streaming functions */ int LZ4_sizeofStreamStateHC(void) { return LZ4_STREAMHCSIZE; } +/* state is presumed correctly sized, aka >= sizeof(LZ4_streamHC_t) + * @return : 0 on success, !=0 if error */ int LZ4_resetStreamStateHC(void* state, char* inputBuffer) { - LZ4HC_CCtx_internal *ctx = &((LZ4_streamHC_t*)state)->internal_donotuse; - if ((((size_t)state) & (sizeof(void*)-1)) != 0) return 1; /* Error : pointer is not aligned for pointer (32 or 64 bits) */ - LZ4_resetStreamHC((LZ4_streamHC_t*)state, ((LZ4_streamHC_t*)state)->internal_donotuse.compressionLevel); - LZ4HC_init(ctx, (const BYTE*)inputBuffer); + LZ4_streamHC_t* const hc4 = LZ4_initStreamHC(state, sizeof(*hc4)); + if (hc4 == NULL) return 1; /* init failed */ + LZ4HC_init_internal (&hc4->internal_donotuse, (const BYTE*)inputBuffer); return 0; } void* LZ4_createHC (const char* inputBuffer) { - LZ4_streamHC_t* hc4 = (LZ4_streamHC_t*)ALLOC(sizeof(LZ4_streamHC_t)); + LZ4_streamHC_t* const hc4 = LZ4_createStreamHC(); if (hc4 == NULL) return NULL; /* not enough memory */ - LZ4_resetStreamHC(hc4, 0 /* compressionLevel */); - LZ4HC_init (&hc4->internal_donotuse, (const BYTE*)inputBuffer); + LZ4HC_init_internal (&hc4->internal_donotuse, (const BYTE*)inputBuffer); return hc4; } -int LZ4_freeHC (void* LZ4HC_Data) { +int LZ4_freeHC (void* LZ4HC_Data) +{ if (!LZ4HC_Data) return 0; /* support free on NULL */ FREEMEM(LZ4HC_Data); return 0; @@ -1070,7 +1228,7 @@ int LZ4_freeHC (void* LZ4HC_Data) { int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* src, char* dst, int srcSize, int cLevel) { - return LZ4HC_compress_generic (&((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse, src, dst, &srcSize, 0, cLevel, noLimit); + return LZ4HC_compress_generic (&((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse, src, dst, &srcSize, 0, cLevel, notLimited); } int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* src, char* dst, int srcSize, int dstCapacity, int cLevel) @@ -1089,7 +1247,7 @@ char* LZ4_slideInputBufferHC(void* LZ4HC_Data) /* ================================================ - * LZ4 Optimal parser (levels 10-12) + * LZ4 Optimal parser (levels [LZ4HC_CLEVEL_OPT_MIN - LZ4HC_CLEVEL_MAX]) * ===============================================*/ typedef struct { int price; @@ -1102,8 +1260,9 @@ typedef struct { LZ4_FORCE_INLINE int LZ4HC_literalsPrice(int const litlen) { int price = litlen; + assert(litlen >= 0); if (litlen >= (int)RUN_MASK) - price += 1 + (litlen-RUN_MASK)/255; + price += 1 + ((litlen-(int)RUN_MASK) / 255); return price; } @@ -1112,11 +1271,13 @@ LZ4_FORCE_INLINE int LZ4HC_literalsPrice(int const litlen) LZ4_FORCE_INLINE int LZ4HC_sequencePrice(int litlen, int mlen) { int price = 1 + 2 ; /* token + 16-bit offset */ + assert(litlen >= 0); + assert(mlen >= MINMATCH); price += LZ4HC_literalsPrice(litlen); if (mlen >= (int)(ML_MASK+MINMATCH)) - price += 1 + (mlen-(ML_MASK+MINMATCH))/255; + price += 1 + ((mlen-(int)(ML_MASK+MINMATCH)) / 255); return price; } @@ -1162,8 +1323,13 @@ static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx, const dictCtx_directive dict, const HCfavor_e favorDecSpeed) { + int retval = 0; #define TRAILING_LITERALS 3 +#ifdef LZ4HC_HEAPMODE + LZ4HC_optimal_t* const opt = (LZ4HC_optimal_t*)ALLOC(sizeof(LZ4HC_optimal_t) * (LZ4_OPT_NUM + TRAILING_LITERALS)); +#else LZ4HC_optimal_t opt[LZ4_OPT_NUM + TRAILING_LITERALS]; /* ~64 KB, which is a bit large for stack... */ +#endif const BYTE* ip = (const BYTE*) source; const BYTE* anchor = ip; @@ -1173,15 +1339,19 @@ static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx, BYTE* op = (BYTE*) dst; BYTE* opSaved = (BYTE*) dst; BYTE* oend = op + dstCapacity; + int ovml = MINMATCH; /* overflow - last sequence */ + const BYTE* ovref = NULL; /* init */ - DEBUGLOG(5, "LZ4HC_compress_optimal"); +#ifdef LZ4HC_HEAPMODE + if (opt == NULL) goto _return_label; +#endif + DEBUGLOG(5, "LZ4HC_compress_optimal(dst=%p, dstCapa=%u)", dst, (unsigned)dstCapacity); *srcSizePtr = 0; - if (limit == limitedDestSize) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */ + if (limit == fillOutput) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */ if (sufficient_len >= LZ4_OPT_NUM) sufficient_len = LZ4_OPT_NUM-1; /* Main Loop */ - assert(ip - anchor < LZ4_MAX_INPUT_SIZE); while (ip <= mflimit) { int const llen = (int)(ip - anchor); int best_mlen, best_off; @@ -1195,8 +1365,11 @@ static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx, int const firstML = firstMatch.len; const BYTE* const matchPos = ip - firstMatch.off; opSaved = op; - if ( LZ4HC_encodeSequence(&ip, &op, &anchor, firstML, matchPos, limit, oend) ) /* updates ip, op and anchor */ + if ( LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), firstML, matchPos, limit, oend) ) { /* updates ip, op and anchor */ + ovml = firstML; + ovref = matchPos; goto _dest_overflow; + } continue; } @@ -1333,11 +1506,12 @@ static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx, } } } /* for (cur = 1; cur <= last_match_pos; cur++) */ + assert(last_match_pos < LZ4_OPT_NUM + TRAILING_LITERALS); best_mlen = opt[last_match_pos].mlen; best_off = opt[last_match_pos].off; cur = last_match_pos - best_mlen; - encode: /* cur, last_match_pos, best_mlen, best_off must be set */ +encode: /* cur, last_match_pos, best_mlen, best_off must be set */ assert(cur < LZ4_OPT_NUM); assert(last_match_pos >= 1); /* == 1 when only one candidate */ DEBUGLOG(6, "reverse traversal, looking for shortest path (last_match_pos=%i)", last_match_pos); @@ -1365,27 +1539,33 @@ static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx, if (ml == 1) { ip++; rPos++; continue; } /* literal; note: can end up with several literals, in which case, skip them */ rPos += ml; assert(ml >= MINMATCH); - assert((offset >= 1) && (offset <= MAX_DISTANCE)); + assert((offset >= 1) && (offset <= LZ4_DISTANCE_MAX)); opSaved = op; - if ( LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ip - offset, limit, oend) ) /* updates ip, op and anchor */ + if ( LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ip - offset, limit, oend) ) { /* updates ip, op and anchor */ + ovml = ml; + ovref = ip - offset; goto _dest_overflow; - } } + } } } } /* while (ip <= mflimit) */ - _last_literals: +_last_literals: /* Encode Last Literals */ { size_t lastRunSize = (size_t)(iend - anchor); /* literals */ - size_t litLength = (lastRunSize + 255 - RUN_MASK) / 255; - size_t const totalSize = 1 + litLength + lastRunSize; - if (limit == limitedDestSize) oend += LASTLITERALS; /* restore correct value */ + size_t llAdd = (lastRunSize + 255 - RUN_MASK) / 255; + size_t const totalSize = 1 + llAdd + lastRunSize; + if (limit == fillOutput) oend += LASTLITERALS; /* restore correct value */ if (limit && (op + totalSize > oend)) { - if (limit == limitedOutput) return 0; /* Check output limit */ + if (limit == limitedOutput) { /* Check output limit */ + retval = 0; + goto _return_label; + } /* adapt lastRunSize to fill 'dst' */ - lastRunSize = (size_t)(oend - op) - 1; - litLength = (lastRunSize + 255 - RUN_MASK) / 255; - lastRunSize -= litLength; + lastRunSize = (size_t)(oend - op) - 1 /*token*/; + llAdd = (lastRunSize + 256 - RUN_MASK) / 256; + lastRunSize -= llAdd; } - ip = anchor + lastRunSize; + DEBUGLOG(6, "Final literal run : %i literals", (int)lastRunSize); + ip = anchor + lastRunSize; /* can be != iend if limit==fillOutput */ if (lastRunSize >= RUN_MASK) { size_t accumulator = lastRunSize - RUN_MASK; @@ -1401,12 +1581,35 @@ static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx, /* End */ *srcSizePtr = (int) (((const char*)ip) - source); - return (int) ((char*)op-dst); + retval = (int) ((char*)op-dst); + goto _return_label; - _dest_overflow: - if (limit == limitedDestSize) { - op = opSaved; /* restore correct out pointer */ - goto _last_literals; - } - return 0; - } +_dest_overflow: +if (limit == fillOutput) { + /* Assumption : ip, anchor, ovml and ovref must be set correctly */ + size_t const ll = (size_t)(ip - anchor); + size_t const ll_addbytes = (ll + 240) / 255; + size_t const ll_totalCost = 1 + ll_addbytes + ll; + BYTE* const maxLitPos = oend - 3; /* 2 for offset, 1 for token */ + DEBUGLOG(6, "Last sequence overflowing (only %i bytes remaining)", (int)(oend-1-opSaved)); + op = opSaved; /* restore correct out pointer */ + if (op + ll_totalCost <= maxLitPos) { + /* ll validated; now adjust match length */ + size_t const bytesLeftForMl = (size_t)(maxLitPos - (op+ll_totalCost)); + size_t const maxMlSize = MINMATCH + (ML_MASK-1) + (bytesLeftForMl * 255); + assert(maxMlSize < INT_MAX); assert(ovml >= 0); + if ((size_t)ovml > maxMlSize) ovml = (int)maxMlSize; + if ((oend + LASTLITERALS) - (op + ll_totalCost + 2) - 1 + ovml >= MFLIMIT) { + DEBUGLOG(6, "Space to end : %i + ml (%i)", (int)((oend + LASTLITERALS) - (op + ll_totalCost + 2) - 1), ovml); + DEBUGLOG(6, "Before : ip = %p, anchor = %p", ip, anchor); + LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ovml, ovref, notLimited, oend); + DEBUGLOG(6, "After : ip = %p, anchor = %p", ip, anchor); + } } + goto _last_literals; +} +_return_label: +#ifdef LZ4HC_HEAPMODE + FREEMEM(opt); +#endif + return retval; +} |