| /* |
| LZ4 HC - High Compression Mode of LZ4 |
| Copyright (C) 2011-2015, 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 source repository : https://github.com/lz4/lz4 |
| - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c |
| */ |
| |
| |
| |
| /* ************************************* |
| * Tuning Parameter |
| ***************************************/ |
| |
| /*! |
| * HEAPMODE : |
| * 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. |
| */ |
| #define LZ4HC_HEAPMODE 0 |
| |
| |
| /* ************************************* |
| * Includes |
| ***************************************/ |
| #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 |
| |
| |
| /* ************************************* |
| * Common LZ4 definition |
| ***************************************/ |
| #define LZ4_COMMONDEFS_ONLY |
| #include "lz4.c" |
| |
| |
| /* ************************************* |
| * Local Constants |
| ***************************************/ |
| #define DICTIONARY_LOGSIZE 16 |
| #define MAXD (1<<DICTIONARY_LOGSIZE) |
| #define MAXD_MASK (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 |
| { |
| 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 */ |
| BYTE* inputBuffer; /* deprecated */ |
| U32 dictLimit; /* below that point, need extDict */ |
| U32 lowLimit; /* below that point, no more dict */ |
| U32 nextToUpdate; /* index from which to continue dictionary update */ |
| U32 compressionLevel; |
| } LZ4HC_Data_Structure; |
| |
| |
| /************************************** |
| * Local Macros |
| **************************************/ |
| #define HASH_FUNCTION(i) (((i) * 2654435761U) >> ((MINMATCH*8)-HASH_LOG)) |
| /* #define DELTANEXTU16(p) chainTable[(p) & MAXD_MASK] */ /* flexible, MAXD dependent */ |
| #define DELTANEXTU16(p) chainTable[(U16)(p)] /* faster */ |
| |
| 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* start) |
| { |
| MEM_INIT((void*)hc4->hashTable, 0, sizeof(hc4->hashTable)); |
| MEM_INIT(hc4->chainTable, 0xFF, sizeof(hc4->chainTable)); |
| hc4->nextToUpdate = 64 KB; |
| hc4->base = start - 64 KB; |
| hc4->end = start; |
| hc4->dictBase = start - 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* const chainTable = hc4->chainTable; |
| U32* const hashTable = hc4->hashTable; |
| const BYTE* const base = hc4->base; |
| U32 const target = (U32)(ip - base); |
| U32 idx = hc4->nextToUpdate; |
| |
| while (idx < target) { |
| U32 const h = LZ4HC_hashPtr(base+idx); |
| size_t delta = idx - hashTable[h]; |
| if (delta>MAX_DISTANCE) delta = MAX_DISTANCE; |
| DELTANEXTU16(idx) = (U16)delta; |
| hashTable[h] = idx; |
| idx++; |
| } |
| |
| hc4->nextToUpdate = target; |
| } |
| |
| |
| 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 const 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 -= DELTANEXTU16(matchIndex); |
| } |
| |
| return (int)ml; |
| } |
| |
| |
| FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch ( |
| LZ4HC_Data_Structure* hc4, |
| const BYTE* const ip, |
| const BYTE* const iLowLimit, |
| const BYTE* const 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 BYTE* const lowPrefixPtr = base + 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; |
| 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) { |
| const BYTE* matchPtr = base + matchIndex; |
| if (*(iLowLimit + longest) == *(matchPtr - delta + longest)) { |
| if (LZ4_read32(matchPtr) == LZ4_read32(ip)) { |
| int mlt = MINMATCH + LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit); |
| int back = 0; |
| |
| while ((ip+back > iLowLimit) |
| && (matchPtr+back > lowPrefixPtr) |
| && (ip[back-1] == matchPtr[back-1])) |
| back--; |
| |
| mlt -= back; |
| |
| if (mlt > longest) { |
| longest = (int)mlt; |
| *matchpos = matchPtr+back; |
| *startpos = ip+back; |
| } |
| } |
| } |
| } else { |
| const BYTE* const matchPtr = dictBase + matchIndex; |
| if (LZ4_read32(matchPtr) == 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, matchPtr+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] == matchPtr[back-1])) back--; |
| mlt -= back; |
| if ((int)mlt > longest) { longest = (int)mlt; *matchpos = base + matchIndex + back; *startpos = ip+back; } |
| } |
| } |
| matchIndex -= DELTANEXTU16(matchIndex); |
| } |
| |
| return longest; |
| } |
| |
| |
| typedef enum { noLimit = 0, limitedOutput = 1 } limitedOutput_directive; |
| |
| #define LZ4HC_DEBUG 0 |
| #if LZ4HC_DEBUG |
| static unsigned debug = 0; |
| #endif |
| |
| 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 LZ4HC_DEBUG |
| if (debug) printf("literal : %u -- match : %u -- offset : %u\n", (U32)(*ip - *anchor), (U32)matchLength, (U32)(*ip-match)); |
| #endif |
| |
| /* 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; |
| } |
| |
| |
| 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 > LZ4HC_MAX_CLEVEL) compressionLevel = LZ4HC_MAX_CLEVEL; |
| if (compressionLevel < 1) compressionLevel = LZ4HC_DEFAULT_CLEVEL; |
| maxNbAttempts = 1 << (compressionLevel-1); |
| 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_sizeofStateHC(void) { return sizeof(LZ4HC_Data_Structure); } |
| |
| int LZ4_compress_HC_extStateHC (void* state, const char* src, char* dst, int srcSize, int maxDstSize, 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*)src); |
| if (maxDstSize < LZ4_compressBound(srcSize)) |
| return LZ4HC_compress_generic (state, src, dst, srcSize, maxDstSize, compressionLevel, limitedOutput); |
| else |
| return LZ4HC_compress_generic (state, src, dst, srcSize, maxDstSize, compressionLevel, noLimit); |
| } |
| |
| int LZ4_compress_HC(const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel) |
| { |
| #if LZ4HC_HEAPMODE==1 |
| LZ4HC_Data_Structure* statePtr = malloc(sizeof(LZ4HC_Data_Structure)); |
| #else |
| LZ4HC_Data_Structure state; |
| LZ4HC_Data_Structure* const statePtr = &state; |
| #endif |
| int cSize = LZ4_compress_HC_extStateHC(statePtr, src, dst, srcSize, maxDstSize, compressionLevel); |
| #if LZ4HC_HEAPMODE==1 |
| free(statePtr); |
| #endif |
| return cSize; |
| } |
| |
| |
| |
| /************************************** |
| * 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) <= sizeof(LZ4_streamHC_t)); /* 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* ctxPtr = (LZ4HC_Data_Structure*) LZ4_streamHCPtr; |
| if (dictSize > 64 KB) { |
| dictionary += dictSize - 64 KB; |
| dictSize = 64 KB; |
| } |
| LZ4HC_init (ctxPtr, (const BYTE*)dictionary); |
| if (dictSize >= 4) LZ4HC_Insert (ctxPtr, (const BYTE*)dictionary +(dictSize-3)); |
| ctxPtr->end = (const BYTE*)dictionary + dictSize; |
| return dictSize; |
| } |
| |
| |
| /* compression */ |
| |
| static void LZ4HC_setExternalDict(LZ4HC_Data_Structure* ctxPtr, const BYTE* newBlock) |
| { |
| if (ctxPtr->end >= ctxPtr->base + 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->end = newBlock; |
| ctxPtr->nextToUpdate = ctxPtr->dictLimit; /* match referencing will resume from there */ |
| } |
| |
| static int LZ4_compressHC_continue_generic (LZ4HC_Data_Structure* ctxPtr, |
| const char* source, char* dest, |
| int inputSize, int maxOutputSize, limitedOutput_directive limit) |
| { |
| /* auto-init if forgotten */ |
| if (ctxPtr->base == NULL) LZ4HC_init (ctxPtr, (const BYTE*) source); |
| |
| /* Check overflow */ |
| if ((size_t)(ctxPtr->end - ctxPtr->base) > 2 GB) { |
| size_t dictSize = (size_t)(ctxPtr->end - ctxPtr->base) - ctxPtr->dictLimit; |
| if (dictSize > 64 KB) dictSize = 64 KB; |
| LZ4_loadDictHC((LZ4_streamHC_t*)ctxPtr, (const char*)(ctxPtr->end) - dictSize, (int)dictSize); |
| } |
| |
| /* Check if blocks follow each other */ |
| if ((const BYTE*)source != ctxPtr->end) LZ4HC_setExternalDict(ctxPtr, (const BYTE*)source); |
| |
| /* Check overlapping input/dictionary space */ |
| { const BYTE* sourceEnd = (const BYTE*) source + inputSize; |
| const BYTE* const dictBegin = ctxPtr->dictBase + ctxPtr->lowLimit; |
| const BYTE* const dictEnd = ctxPtr->dictBase + ctxPtr->dictLimit; |
| if ((sourceEnd > dictBegin) && ((const BYTE*)source < dictEnd)) { |
| 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, source, dest, inputSize, maxOutputSize, ctxPtr->compressionLevel, limit); |
| } |
| |
| int LZ4_compress_HC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize, int maxOutputSize) |
| { |
| if (maxOutputSize < LZ4_compressBound(inputSize)) |
| return LZ4_compressHC_continue_generic ((LZ4HC_Data_Structure*)LZ4_streamHCPtr, source, dest, inputSize, maxOutputSize, limitedOutput); |
| else |
| return LZ4_compressHC_continue_generic ((LZ4HC_Data_Structure*)LZ4_streamHCPtr, source, dest, inputSize, maxOutputSize, noLimit); |
| } |
| |
| |
| /* dictionary saving */ |
| |
| int LZ4_saveDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, char* safeBuffer, int dictSize) |
| { |
| LZ4HC_Data_Structure* const streamPtr = (LZ4HC_Data_Structure*)LZ4_streamHCPtr; |
| int const 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; |
| 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; |
| } |
| return dictSize; |
| } |
| |
| |
| /*********************************** |
| * Deprecated Functions |
| ***********************************/ |
| /* Deprecated compression functions */ |
| /* These functions are planned to start generate warnings by r131 approximately */ |
| 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); } |
| int LZ4_compressHC2_limitedOutput(const char* src, char* dst, int srcSize, int maxDstSize, int cLevel) { return LZ4_compress_HC(src, dst, srcSize, maxDstSize, cLevel); } |
| int LZ4_compressHC_withStateHC (void* state, const char* src, char* dst, int srcSize) { return LZ4_compress_HC_extStateHC (state, src, dst, srcSize, LZ4_compressBound(srcSize), 0); } |
| int LZ4_compressHC_limitedOutput_withStateHC (void* state, const char* src, char* dst, int srcSize, int maxDstSize) { return LZ4_compress_HC_extStateHC (state, src, dst, srcSize, maxDstSize, 0); } |
| int LZ4_compressHC2_withStateHC (void* state, const char* src, char* dst, int srcSize, int cLevel) { return LZ4_compress_HC_extStateHC(state, src, dst, srcSize, LZ4_compressBound(srcSize), cLevel); } |
| int LZ4_compressHC2_limitedOutput_withStateHC (void* state, const char* src, char* dst, int srcSize, int maxDstSize, int cLevel) { return LZ4_compress_HC_extStateHC(state, src, dst, srcSize, maxDstSize, cLevel); } |
| int LZ4_compressHC_continue (LZ4_streamHC_t* ctx, const char* src, char* dst, int srcSize) { return LZ4_compress_HC_continue (ctx, src, dst, srcSize, LZ4_compressBound(srcSize)); } |
| int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* ctx, const char* src, char* dst, int srcSize, int maxDstSize) { return LZ4_compress_HC_continue (ctx, src, dst, srcSize, maxDstSize); } |
| |
| |
| /* Deprecated streaming functions */ |
| /* These functions currently generate deprecation warnings */ |
| int LZ4_sizeofStreamStateHC(void) { return LZ4_STREAMHCSIZE; } |
| |
| int LZ4_resetStreamStateHC(void* state, 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); |
| ((LZ4HC_Data_Structure*)state)->inputBuffer = (BYTE*)inputBuffer; |
| return 0; |
| } |
| |
| void* LZ4_createHC (char* inputBuffer) |
| { |
| void* hc4 = ALLOCATOR(1, sizeof(LZ4HC_Data_Structure)); |
| if (hc4 == NULL) return NULL; /* not enough memory */ |
| LZ4HC_init ((LZ4HC_Data_Structure*)hc4, (const BYTE*)inputBuffer); |
| ((LZ4HC_Data_Structure*)hc4)->inputBuffer = (BYTE*)inputBuffer; |
| return hc4; |
| } |
| |
| int LZ4_freeHC (void* LZ4HC_Data) |
| { |
| FREEMEM(LZ4HC_Data); |
| return (0); |
| } |
| |
| 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; |
| int dictSize = LZ4_saveDictHC((LZ4_streamHC_t*)LZ4HC_Data, (char*)(hc4->inputBuffer), 64 KB); |
| return (char*)(hc4->inputBuffer + dictSize); |
| } |