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Diffstat (limited to 'lib/lz4hc.c')
| -rw-r--r-- | lib/lz4hc.c | 768 |
1 files changed, 768 insertions, 0 deletions
diff --git a/lib/lz4hc.c b/lib/lz4hc.c new file mode 100644 index 0000000..89f0db0 --- /dev/null +++ b/lib/lz4hc.c @@ -0,0 +1,768 @@ +/* +LZ4 HC - High Compression Mode of LZ4 +Copyright (C) 2011-2014, Yann Collet. +BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: + +* Redistributions of source code must retain the above copyright +notice, this list of conditions and the following disclaimer. +* Redistributions in binary form must reproduce the above +copyright notice, this list of conditions and the following disclaimer +in the documentation and/or other materials provided with the +distribution. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +You can contact the author at : +- LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html +- LZ4 source repository : http://code.google.com/p/lz4/ +*/ + + + +/************************************** + Tuning Parameter +**************************************/ +#define LZ4HC_DEFAULT_COMPRESSIONLEVEL 8 + + +/************************************** + Includes +**************************************/ +#include "lz4.h" +#include "lz4hc.h" + + +/************************************** + Local Compiler Options +**************************************/ +#if defined(__GNUC__) +# pragma GCC diagnostic ignored "-Wunused-function" +#endif + +#if defined (__clang__) +# pragma clang diagnostic ignored "-Wunused-function" +#endif + +#if defined(_MSC_VER) /* Visual Studio */ +# pragma warning(disable : 4201) /* disable: C4201: unnamed struct/union*/ +#endif + + +/************************************** + Common LZ4 definition +**************************************/ +#define LZ4_COMMONDEFS_ONLY +#include "lz4.c" + + +/************************************** + Local Constants +**************************************/ +#define DICTIONARY_LOGSIZE 16 +#define MAXD (1<<DICTIONARY_LOGSIZE) +#define MAXD_MASK ((U32)(MAXD - 1)) + +#define HASH_LOG (DICTIONARY_LOGSIZE-1) +#define HASHTABLESIZE (1 << HASH_LOG) +#define HASH_MASK (HASHTABLESIZE - 1) + +#define OPTIMAL_ML (int)((ML_MASK-1)+MINMATCH) + + +/************************************** + Local Types +**************************************/ +typedef struct +{ + union { + U64 alignedOn8Bytes; /* force 8-bytes alignment on 32-bits systems */ + U32 hashTable[HASHTABLESIZE]; + }; + U16 chainTable[MAXD]; + const BYTE* end; /* next block here to continue on current prefix */ + const BYTE* base; /* All index relative to this position */ + const BYTE* dictBase; /* alternate base for extDict */ + U32 dictLimit; /* below that point, need extDict */ + U32 lowLimit; /* below that point, no more dict */ + U32 nextToUpdate; + U32 compressionLevel; + const BYTE* inputBuffer; /* deprecated */ +} LZ4HC_Data_Structure; + + +/************************************** + Local Macros +**************************************/ +#define HASH_FUNCTION(i) (((i) * 2654435761U) >> ((MINMATCH*8)-HASH_LOG)) +#define DELTANEXT(p) chainTable[(size_t)(p) & MAXD_MASK] +#define GETNEXT(p) ((p) - (size_t)DELTANEXT(p)) + +static U32 LZ4HC_hashPtr(const void* ptr) { return HASH_FUNCTION(LZ4_read32(ptr)); } + + + +/************************************** + HC Compression +**************************************/ +static void LZ4HC_init (LZ4HC_Data_Structure* hc4, const BYTE* base) +{ + MEM_INIT((void*)hc4->hashTable, 0, sizeof(hc4->hashTable)); + MEM_INIT(hc4->chainTable, 0xFF, sizeof(hc4->chainTable)); + hc4->nextToUpdate = 64 KB; + hc4->base = base - 64 KB; + hc4->inputBuffer = base; + hc4->end = base; + hc4->dictBase = base - 64 KB; + hc4->dictLimit = 64 KB; + hc4->lowLimit = 64 KB; +} + + +/* Update chains up to ip (excluded) */ +FORCE_INLINE void LZ4HC_Insert (LZ4HC_Data_Structure* hc4, const BYTE* ip) +{ + U16* chainTable = hc4->chainTable; + U32* HashTable = hc4->hashTable; + const BYTE* const base = hc4->base; + const U32 target = (U32)(ip - base); + U32 idx = hc4->nextToUpdate; + + while(idx < target) + { + U32 h = LZ4HC_hashPtr(base+idx); + size_t delta = idx - HashTable[h]; + if (delta>MAX_DISTANCE) delta = MAX_DISTANCE; + chainTable[idx & 0xFFFF] = (U16)delta; + HashTable[h] = idx; + idx++; + } + + hc4->nextToUpdate = target; +} + + +static void LZ4HC_setExternalDict(LZ4HC_Data_Structure* ctxPtr, const BYTE* newBlock) +{ + if (ctxPtr->end >= ctxPtr->base + 4) + LZ4HC_Insert (ctxPtr, ctxPtr->end-3); // finish referencing dictionary content + // Note : need to handle risk of index overflow + // Use only one memory segment for dict, so any previous External Dict 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->end = newBlock; + ctxPtr->nextToUpdate = ctxPtr->dictLimit; // reference table must skip to from beginning of block +} + + +FORCE_INLINE int LZ4HC_InsertAndFindBestMatch (LZ4HC_Data_Structure* hc4, // Index table will be updated + const BYTE* ip, const BYTE* const iLimit, + const BYTE** matchpos, + const int maxNbAttempts) +{ + U16* const chainTable = hc4->chainTable; + U32* const HashTable = hc4->hashTable; + const BYTE* const base = hc4->base; + const BYTE* const dictBase = hc4->dictBase; + const U32 dictLimit = hc4->dictLimit; + const U32 lowLimit = (hc4->lowLimit + 64 KB > (U32)(ip-base)) ? hc4->lowLimit : (U32)(ip - base) - (64 KB - 1); + U32 matchIndex; + const BYTE* match; + int nbAttempts=maxNbAttempts; + size_t ml=0; + + /* HC4 match finder */ + LZ4HC_Insert(hc4, ip); + matchIndex = HashTable[LZ4HC_hashPtr(ip)]; + + while ((matchIndex>=lowLimit) && (nbAttempts)) + { + nbAttempts--; + if (matchIndex >= dictLimit) + { + match = base + matchIndex; + if (*(match+ml) == *(ip+ml) + && (LZ4_read32(match) == LZ4_read32(ip))) + { + size_t mlt = LZ4_count(ip+MINMATCH, match+MINMATCH, iLimit) + MINMATCH; + if (mlt > ml) { ml = mlt; *matchpos = match; } + } + } + else + { + match = dictBase + matchIndex; + if (LZ4_read32(match) == LZ4_read32(ip)) + { + size_t mlt; + const BYTE* vLimit = ip + (dictLimit - matchIndex); + if (vLimit > iLimit) vLimit = iLimit; + mlt = LZ4_count(ip+MINMATCH, match+MINMATCH, vLimit) + MINMATCH; + if ((ip+mlt == vLimit) && (vLimit < iLimit)) + mlt += LZ4_count(ip+mlt, base+dictLimit, iLimit); + if (mlt > ml) { ml = mlt; *matchpos = base + matchIndex; } // virtual matchpos + } + } + matchIndex -= chainTable[matchIndex & 0xFFFF]; + } + + return (int)ml; +} + + +FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch ( + LZ4HC_Data_Structure* hc4, + const BYTE* ip, + const BYTE* iLowLimit, + const BYTE* iHighLimit, + int longest, + const BYTE** matchpos, + const BYTE** startpos, + const int maxNbAttempts) +{ + U16* const chainTable = hc4->chainTable; + U32* const HashTable = hc4->hashTable; + const BYTE* const base = hc4->base; + const U32 dictLimit = hc4->dictLimit; + const U32 lowLimit = (hc4->lowLimit + 64 KB > (U32)(ip-base)) ? hc4->lowLimit : (U32)(ip - base) - (64 KB - 1); + const BYTE* const dictBase = hc4->dictBase; + const BYTE* match; + U32 matchIndex; + int nbAttempts = maxNbAttempts; + int delta = (int)(ip-iLowLimit); + + + /* First Match */ + LZ4HC_Insert(hc4, ip); + matchIndex = HashTable[LZ4HC_hashPtr(ip)]; + + while ((matchIndex>=lowLimit) && (nbAttempts)) + { + nbAttempts--; + if (matchIndex >= dictLimit) + { + match = base + matchIndex; + if (*(iLowLimit + longest) == *(match - delta + longest)) + if (LZ4_read32(match) == LZ4_read32(ip)) + { + const BYTE* startt = ip; + const BYTE* tmpMatch = match; + const BYTE* const matchEnd = ip + MINMATCH + LZ4_count(ip+MINMATCH, match+MINMATCH, iHighLimit); + + while ((startt>iLowLimit) && (tmpMatch > iLowLimit) && (startt[-1] == tmpMatch[-1])) {startt--; tmpMatch--;} + + if ((matchEnd-startt) > longest) + { + longest = (int)(matchEnd-startt); + *matchpos = tmpMatch; + *startpos = startt; + } + } + } + else + { + match = dictBase + matchIndex; + if (LZ4_read32(match) == LZ4_read32(ip)) + { + size_t mlt; + int back=0; + const BYTE* vLimit = ip + (dictLimit - matchIndex); + if (vLimit > iHighLimit) vLimit = iHighLimit; + mlt = LZ4_count(ip+MINMATCH, match+MINMATCH, vLimit) + MINMATCH; + if ((ip+mlt == vLimit) && (vLimit < iHighLimit)) + mlt += LZ4_count(ip+mlt, base+dictLimit, iHighLimit); + while ((ip+back > iLowLimit) && (matchIndex+back > lowLimit) && (ip[back-1] == match[back-1])) back--; + mlt -= back; + if ((int)mlt > longest) { longest = (int)mlt; *matchpos = base + matchIndex + back; *startpos = ip+back; } + } + } + matchIndex -= chainTable[matchIndex & 0xFFFF]; + } + + return longest; +} + + +typedef enum { noLimit = 0, limitedOutput = 1 } limitedOutput_directive; + +//static unsigned debug = 0; + +FORCE_INLINE int LZ4HC_encodeSequence ( + const BYTE** ip, + BYTE** op, + const BYTE** anchor, + int matchLength, + const BYTE* const match, + limitedOutput_directive limitedOutputBuffer, + BYTE* oend) +{ + int length; + BYTE* token; + + //if (debug) printf("literal : %u -- match : %u -- offset : %u\n", (U32)(*ip - *anchor), (U32)matchLength, (U32)(*ip-match)); // debug + + /* Encode Literal length */ + length = (int)(*ip - *anchor); + token = (*op)++; + if ((limitedOutputBuffer) && ((*op + (length>>8) + length + (2 + 1 + LASTLITERALS)) > oend)) return 1; /* Check output limit */ + if (length>=(int)RUN_MASK) { int len; *token=(RUN_MASK<<ML_BITS); len = length-RUN_MASK; for(; len > 254 ; len-=255) *(*op)++ = 255; *(*op)++ = (BYTE)len; } + else *token = (BYTE)(length<<ML_BITS); + + /* Copy Literals */ + LZ4_wildCopy(*op, *anchor, (*op) + length); + *op += length; + + /* Encode Offset */ + LZ4_writeLE16(*op, (U16)(*ip-match)); *op += 2; + + /* Encode MatchLength */ + length = (int)(matchLength-MINMATCH); + if ((limitedOutputBuffer) && (*op + (length>>8) + (1 + LASTLITERALS) > oend)) return 1; /* Check output limit */ + if (length>=(int)ML_MASK) { *token+=ML_MASK; length-=ML_MASK; for(; length > 509 ; length-=510) { *(*op)++ = 255; *(*op)++ = 255; } if (length > 254) { length-=255; *(*op)++ = 255; } *(*op)++ = (BYTE)length; } + else *token += (BYTE)(length); + + /* Prepare next loop */ + *ip += matchLength; + *anchor = *ip; + + return 0; +} + + +#define MAX_COMPRESSION_LEVEL 16 +static int LZ4HC_compress_generic ( + void* ctxvoid, + const char* source, + char* dest, + int inputSize, + int maxOutputSize, + int compressionLevel, + limitedOutput_directive limit + ) +{ + LZ4HC_Data_Structure* ctx = (LZ4HC_Data_Structure*) ctxvoid; + const BYTE* ip = (const BYTE*) source; + const BYTE* anchor = ip; + const BYTE* const iend = ip + inputSize; + const BYTE* const mflimit = iend - MFLIMIT; + const BYTE* const matchlimit = (iend - LASTLITERALS); + + BYTE* op = (BYTE*) dest; + BYTE* const oend = op + maxOutputSize; + + unsigned maxNbAttempts; + int ml, ml2, ml3, ml0; + const BYTE* ref=NULL; + const BYTE* start2=NULL; + const BYTE* ref2=NULL; + const BYTE* start3=NULL; + const BYTE* ref3=NULL; + const BYTE* start0; + const BYTE* ref0; + + + /* init */ + if (compressionLevel > MAX_COMPRESSION_LEVEL) compressionLevel = MAX_COMPRESSION_LEVEL; + if (compressionLevel == 0) compressionLevel = LZ4HC_DEFAULT_COMPRESSIONLEVEL; + maxNbAttempts = 1 << compressionLevel; + ctx->end += inputSize; + + ip++; + + /* Main Loop */ + while (ip < mflimit) + { + ml = LZ4HC_InsertAndFindBestMatch (ctx, ip, matchlimit, (&ref), maxNbAttempts); + if (!ml) { ip++; continue; } + + /* saved, in case we would skip too much */ + start0 = ip; + ref0 = ref; + ml0 = ml; + +_Search2: + if (ip+ml < mflimit) + ml2 = LZ4HC_InsertAndGetWiderMatch(ctx, ip + ml - 2, ip + 1, matchlimit, ml, &ref2, &start2, maxNbAttempts); + else ml2 = ml; + + if (ml2 == ml) /* No better match */ + { + if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) return 0; + continue; + } + + if (start0 < ip) + { + if (start2 < ip + ml0) /* empirical */ + { + ip = start0; + ref = ref0; + ml = ml0; + } + } + + /* Here, start0==ip */ + if ((start2 - ip) < 3) /* First Match too small : removed */ + { + ml = ml2; + ip = start2; + ref =ref2; + goto _Search2; + } + +_Search3: + /* + * Currently we have : + * ml2 > ml1, and + * ip1+3 <= ip2 (usually < ip1+ml1) + */ + if ((start2 - ip) < OPTIMAL_ML) + { + int correction; + int new_ml = ml; + if (new_ml > OPTIMAL_ML) new_ml = OPTIMAL_ML; + if (ip+new_ml > start2 + ml2 - MINMATCH) new_ml = (int)(start2 - ip) + ml2 - MINMATCH; + correction = new_ml - (int)(start2 - ip); + if (correction > 0) + { + start2 += correction; + ref2 += correction; + ml2 -= correction; + } + } + /* 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); + else ml3 = ml2; + + if (ml3 == ml2) /* No better match : 2 sequences to encode */ + { + /* ip & ref are known; Now for ml */ + if (start2 < ip+ml) ml = (int)(start2 - ip); + /* Now, encode 2 sequences */ + if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) return 0; + ip = start2; + if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml2, ref2, limit, oend)) return 0; + continue; + } + + if (start3 < ip+ml+3) /* Not enough space for match 2 : remove it */ + { + if (start3 >= (ip+ml)) /* can write Seq1 immediately ==> Seq2 is removed, so Seq3 becomes Seq1 */ + { + if (start2 < ip+ml) + { + int correction = (int)(ip+ml - start2); + start2 += correction; + ref2 += correction; + ml2 -= correction; + if (ml2 < MINMATCH) + { + start2 = start3; + ref2 = ref3; + ml2 = ml3; + } + } + + if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) return 0; + ip = start3; + ref = ref3; + ml = ml3; + + start0 = start2; + ref0 = ref2; + ml0 = ml2; + goto _Search2; + } + + start2 = start3; + ref2 = ref3; + ml2 = ml3; + goto _Search3; + } + + /* + * OK, now we have 3 ascending matches; let's write at least the first one + * ip & ref are known; Now for ml + */ + if (start2 < ip+ml) + { + if ((start2 - ip) < (int)ML_MASK) + { + int correction; + if (ml > OPTIMAL_ML) ml = OPTIMAL_ML; + if (ip + ml > start2 + ml2 - MINMATCH) ml = (int)(start2 - ip) + ml2 - MINMATCH; + correction = ml - (int)(start2 - ip); + if (correction > 0) + { + start2 += correction; + ref2 += correction; + ml2 -= correction; + } + } + else + { + ml = (int)(start2 - ip); + } + } + if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) return 0; + + ip = start2; + ref = ref2; + ml = ml2; + + start2 = start3; + ref2 = ref3; + ml2 = ml3; + + goto _Search3; + } + + /* Encode Last Literals */ + { + int lastRun = (int)(iend - anchor); + if ((limit) && (((char*)op - dest) + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > (U32)maxOutputSize)) return 0; /* Check output limit */ + if (lastRun>=(int)RUN_MASK) { *op++=(RUN_MASK<<ML_BITS); lastRun-=RUN_MASK; for(; lastRun > 254 ; lastRun-=255) *op++ = 255; *op++ = (BYTE) lastRun; } + else *op++ = (BYTE)(lastRun<<ML_BITS); + memcpy(op, anchor, iend - anchor); + op += iend-anchor; + } + + /* End */ + return (int) (((char*)op)-dest); +} + + +int LZ4_compressHC2(const char* source, char* dest, int inputSize, int compressionLevel) +{ + LZ4HC_Data_Structure ctx; + LZ4HC_init(&ctx, (const BYTE*)source); + return LZ4HC_compress_generic (&ctx, source, dest, inputSize, 0, compressionLevel, noLimit); +} + +int LZ4_compressHC(const char* source, char* dest, int inputSize) { return LZ4_compressHC2(source, dest, inputSize, 0); } + +int LZ4_compressHC2_limitedOutput(const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel) +{ + LZ4HC_Data_Structure ctx; + LZ4HC_init(&ctx, (const BYTE*)source); + return LZ4HC_compress_generic (&ctx, source, dest, inputSize, maxOutputSize, compressionLevel, limitedOutput); +} + +int LZ4_compressHC_limitedOutput(const char* source, char* dest, int inputSize, int maxOutputSize) +{ + return LZ4_compressHC2_limitedOutput(source, dest, inputSize, maxOutputSize, 0); +} + + +/***************************** + Using external allocation +*****************************/ +int LZ4_sizeofStateHC(void) { return sizeof(LZ4HC_Data_Structure); } + + +int LZ4_compressHC2_withStateHC (void* state, const char* source, char* dest, int inputSize, int compressionLevel) +{ + if (((size_t)(state)&(sizeof(void*)-1)) != 0) return 0; /* Error : state is not aligned for pointers (32 or 64 bits) */ + LZ4HC_init ((LZ4HC_Data_Structure*)state, (const BYTE*)source); + return LZ4HC_compress_generic (state, source, dest, inputSize, 0, compressionLevel, noLimit); +} + +int LZ4_compressHC_withStateHC (void* state, const char* source, char* dest, int inputSize) +{ return LZ4_compressHC2_withStateHC (state, source, dest, inputSize, 0); } + + +int LZ4_compressHC2_limitedOutput_withStateHC (void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel) +{ + if (((size_t)(state)&(sizeof(void*)-1)) != 0) return 0; /* Error : state is not aligned for pointers (32 or 64 bits) */ + LZ4HC_init ((LZ4HC_Data_Structure*)state, (const BYTE*)source); + return LZ4HC_compress_generic (state, source, dest, inputSize, maxOutputSize, compressionLevel, limitedOutput); +} + +int LZ4_compressHC_limitedOutput_withStateHC (void* state, const char* source, char* dest, int inputSize, int maxOutputSize) +{ return LZ4_compressHC2_limitedOutput_withStateHC (state, source, dest, inputSize, maxOutputSize, 0); } + + +/************************************** + Experimental Streaming Functions +**************************************/ +/* allocation */ +LZ4_streamHC_t* LZ4_createStreamHC(void) { return (LZ4_streamHC_t*)malloc(sizeof(LZ4_streamHC_t)); } +int LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr) { free(LZ4_streamHCPtr); return 0; }; + + +/* initialization */ +void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel) +{ + LZ4_STATIC_ASSERT(sizeof(LZ4HC_Data_Structure) <= LZ4_STREAMHCSIZE); /* if compilation fails here, LZ4_STREAMHCSIZE must be increased */ + ((LZ4HC_Data_Structure*)LZ4_streamHCPtr)->base = NULL; + ((LZ4HC_Data_Structure*)LZ4_streamHCPtr)->compressionLevel = (unsigned)compressionLevel; +} + +int LZ4_loadDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, const char* dictionary, int dictSize) +{ + LZ4HC_Data_Structure* streamPtr = (LZ4HC_Data_Structure*) LZ4_streamHCPtr; + if (dictSize > 64 KB) + { + dictionary += dictSize - 64 KB; + dictSize = 64 KB; + } + LZ4HC_init (streamPtr, (const BYTE*)dictionary); + if (dictSize >= 4) LZ4HC_Insert (streamPtr, (const BYTE*)dictionary +(dictSize-3)); + streamPtr->end = (const BYTE*)dictionary + dictSize; + return dictSize; +} + + +/* compression */ + +static int LZ4_compressHC_continue_generic (LZ4HC_Data_Structure* dsPtr, + const char* source, char* dest, + int inputSize, int maxOutputSize, limitedOutput_directive limit) +{ + /* auto-init if forgotten */ + if (dsPtr->base == NULL) + LZ4HC_init (dsPtr, (const BYTE*) source); + + /* Check overflow */ + if ((size_t)(dsPtr->end - dsPtr->base) > 2 GB) + { + size_t dictSize = (size_t)(dsPtr->end - dsPtr->base) - dsPtr->dictLimit; + if (dictSize > 64 KB) dictSize = 64 KB; + + LZ4_loadDictHC((LZ4_streamHC_t*)dsPtr, (const char*)(dsPtr->end) - dictSize, (int)dictSize); + } + + /* Check if blocks follow each other */ + if ((const BYTE*)source != dsPtr->end) LZ4HC_setExternalDict(dsPtr, (const BYTE*)source); + + /* Check overlapping input/dictionary space */ + { + const BYTE* sourceEnd = (const BYTE*) source + inputSize; + const BYTE* dictBegin = dsPtr->dictBase + dsPtr->lowLimit; + const BYTE* dictEnd = dsPtr->dictBase + dsPtr->dictLimit; + if ((sourceEnd > dictBegin) && ((BYTE*)source < dictEnd)) + { + if (sourceEnd > dictEnd) sourceEnd = dictEnd; + dsPtr->lowLimit = (U32)(sourceEnd - dsPtr->dictBase); + if (dsPtr->dictLimit - dsPtr->lowLimit < 4) dsPtr->lowLimit = dsPtr->dictLimit; + } + } + + return LZ4HC_compress_generic (dsPtr, source, dest, inputSize, maxOutputSize, dsPtr->compressionLevel, limit); +} + +int LZ4_compressHC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize) +{ + return LZ4_compressHC_continue_generic ((LZ4HC_Data_Structure*)LZ4_streamHCPtr, source, dest, inputSize, 0, noLimit); +} + +int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize, int maxOutputSize) +{ + return LZ4_compressHC_continue_generic ((LZ4HC_Data_Structure*)LZ4_streamHCPtr, source, dest, inputSize, maxOutputSize, limitedOutput); +} + + +/* dictionary saving */ + +int LZ4_saveDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, char* safeBuffer, int dictSize) +{ + LZ4HC_Data_Structure* streamPtr = (LZ4HC_Data_Structure*)LZ4_streamHCPtr; + int prefixSize = (int)(streamPtr->end - (streamPtr->base + streamPtr->dictLimit)); + if (dictSize > 64 KB) dictSize = 64 KB; + if (dictSize < 4) dictSize = 0; + if (dictSize > prefixSize) dictSize = prefixSize; + memcpy(safeBuffer, streamPtr->end - dictSize, dictSize); + //LZ4_loadDictHC(LZ4_streamHCPtr, safeBuffer, dictSize); + { + U32 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; + } + return dictSize; +} + + +/*********************************** + * Deprecated Functions + ***********************************/ +int LZ4_sizeofStreamStateHC(void) { return LZ4_STREAMHCSIZE; } + +int LZ4_resetStreamStateHC(void* state, const char* inputBuffer) +{ + if ((((size_t)state) & (sizeof(void*)-1)) != 0) return 1; /* Error : pointer is not aligned for pointer (32 or 64 bits) */ + LZ4HC_init((LZ4HC_Data_Structure*)state, (const BYTE*)inputBuffer); + return 0; +} + +void* LZ4_createHC (const char* inputBuffer) +{ + void* hc4 = ALLOCATOR(1, sizeof(LZ4HC_Data_Structure)); + LZ4HC_init ((LZ4HC_Data_Structure*)hc4, (const BYTE*)inputBuffer); + return hc4; +} + +int LZ4_freeHC (void* LZ4HC_Data) +{ + FREEMEM(LZ4HC_Data); + return (0); +} + +/* +int LZ4_compressHC_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize) +{ +return LZ4HC_compress_generic (LZ4HC_Data, source, dest, inputSize, 0, 0, noLimit); +} +int LZ4_compressHC_limitedOutput_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int maxOutputSize) +{ +return LZ4HC_compress_generic (LZ4HC_Data, source, dest, inputSize, maxOutputSize, 0, limitedOutput); +} +*/ + +int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int compressionLevel) +{ + return LZ4HC_compress_generic (LZ4HC_Data, source, dest, inputSize, 0, compressionLevel, noLimit); +} + +int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel) +{ + return LZ4HC_compress_generic (LZ4HC_Data, source, dest, inputSize, maxOutputSize, compressionLevel, limitedOutput); +} + +char* LZ4_slideInputBufferHC(void* LZ4HC_Data) +{ + LZ4HC_Data_Structure* hc4 = (LZ4HC_Data_Structure*)LZ4HC_Data; + size_t distance = (hc4->end - 64 KB) - hc4->inputBuffer; + + if (hc4->end <= hc4->inputBuffer + 64 KB) return (char*)(hc4->end); /* no update : less than 64KB within buffer */ + + distance = (distance >> 16) << 16; /* Must be a multiple of 64 KB */ + LZ4HC_Insert(hc4, hc4->end - MINMATCH); + memcpy((void*)(hc4->end - 64 KB - distance), (const void*)(hc4->end - 64 KB), 64 KB); + hc4->base -= distance; + if ((U32)(hc4->inputBuffer - hc4->base) > 1 GB + 64 KB) /* Avoid overflow */ + { + int i; + hc4->base += 1 GB; + for (i=0; i<HASHTABLESIZE; i++) hc4->hashTable[i] -= 1 GB; + } + hc4->end -= distance; + return (char*)(hc4->end); +} |