757 lines
26 KiB
C
757 lines
26 KiB
C
/*
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LZ4 HC - High Compression Mode of LZ4
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Copyright (C) 2011-2015, Yann Collet.
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BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are
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met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above
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copyright notice, this list of conditions and the following disclaimer
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in the documentation and/or other materials provided with the
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distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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You can contact the author at :
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- LZ4 source repository : https://github.com/Cyan4973/lz4
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- LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
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*/
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/**************************************
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Tuning Parameter
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**************************************/
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static const int LZ4HC_compressionLevel_default = 9;
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/**************************************
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Includes
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**************************************/
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#include "lz4hc.h"
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/**************************************
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Local Compiler Options
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**************************************/
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#if defined(__GNUC__)
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# pragma GCC diagnostic ignored "-Wunused-function"
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#endif
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#if defined (__clang__)
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# pragma clang diagnostic ignored "-Wunused-function"
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#endif
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/**************************************
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Common LZ4 definition
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**************************************/
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#define LZ4_COMMONDEFS_ONLY
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#include "lz4.c"
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/**************************************
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Local Constants
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**************************************/
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#define DICTIONARY_LOGSIZE 16
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#define MAXD (1<<DICTIONARY_LOGSIZE)
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#define MAXD_MASK ((U32)(MAXD - 1))
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#define HASH_LOG (DICTIONARY_LOGSIZE-1)
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#define HASHTABLESIZE (1 << HASH_LOG)
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#define HASH_MASK (HASHTABLESIZE - 1)
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#define OPTIMAL_ML (int)((ML_MASK-1)+MINMATCH)
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static const int g_maxCompressionLevel = 16;
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/**************************************
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Local Types
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**************************************/
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typedef struct
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{
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U32 hashTable[HASHTABLESIZE];
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U16 chainTable[MAXD];
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const BYTE* end; /* next block here to continue on current prefix */
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const BYTE* base; /* All index relative to this position */
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const BYTE* dictBase; /* alternate base for extDict */
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const BYTE* inputBuffer;/* deprecated */
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U32 dictLimit; /* below that point, need extDict */
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U32 lowLimit; /* below that point, no more dict */
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U32 nextToUpdate;
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U32 compressionLevel;
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} LZ4HC_Data_Structure;
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/**************************************
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Local Macros
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**************************************/
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#define HASH_FUNCTION(i) (((i) * 2654435761U) >> ((MINMATCH*8)-HASH_LOG))
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#define DELTANEXT(p) chainTable[(size_t)(p) & MAXD_MASK]
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#define GETNEXT(p) ((p) - (size_t)DELTANEXT(p))
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static U32 LZ4HC_hashPtr(const void* ptr) { return HASH_FUNCTION(LZ4_read32(ptr)); }
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/**************************************
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HC Compression
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**************************************/
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static void LZ4HC_init (LZ4HC_Data_Structure* hc4, const BYTE* start)
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{
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MEM_INIT((void*)hc4->hashTable, 0, sizeof(hc4->hashTable));
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MEM_INIT(hc4->chainTable, 0xFF, sizeof(hc4->chainTable));
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hc4->nextToUpdate = 64 KB;
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hc4->base = start - 64 KB;
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hc4->inputBuffer = start;
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hc4->end = start;
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hc4->dictBase = start - 64 KB;
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hc4->dictLimit = 64 KB;
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hc4->lowLimit = 64 KB;
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}
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/* Update chains up to ip (excluded) */
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FORCE_INLINE void LZ4HC_Insert (LZ4HC_Data_Structure* hc4, const BYTE* ip)
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{
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U16* chainTable = hc4->chainTable;
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U32* HashTable = hc4->hashTable;
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const BYTE* const base = hc4->base;
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const U32 target = (U32)(ip - base);
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U32 idx = hc4->nextToUpdate;
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while(idx < target)
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{
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U32 h = LZ4HC_hashPtr(base+idx);
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size_t delta = idx - HashTable[h];
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if (delta>MAX_DISTANCE) delta = MAX_DISTANCE;
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chainTable[idx & 0xFFFF] = (U16)delta;
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HashTable[h] = idx;
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idx++;
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}
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hc4->nextToUpdate = target;
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}
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FORCE_INLINE int LZ4HC_InsertAndFindBestMatch (LZ4HC_Data_Structure* hc4, /* Index table will be updated */
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const BYTE* ip, const BYTE* const iLimit,
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const BYTE** matchpos,
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const int maxNbAttempts)
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{
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U16* const chainTable = hc4->chainTable;
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U32* const HashTable = hc4->hashTable;
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const BYTE* const base = hc4->base;
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const BYTE* const dictBase = hc4->dictBase;
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const U32 dictLimit = hc4->dictLimit;
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const U32 lowLimit = (hc4->lowLimit + 64 KB > (U32)(ip-base)) ? hc4->lowLimit : (U32)(ip - base) - (64 KB - 1);
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U32 matchIndex;
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const BYTE* match;
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int nbAttempts=maxNbAttempts;
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size_t ml=0;
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/* HC4 match finder */
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LZ4HC_Insert(hc4, ip);
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matchIndex = HashTable[LZ4HC_hashPtr(ip)];
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while ((matchIndex>=lowLimit) && (nbAttempts))
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{
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nbAttempts--;
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if (matchIndex >= dictLimit)
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{
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match = base + matchIndex;
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if (*(match+ml) == *(ip+ml)
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&& (LZ4_read32(match) == LZ4_read32(ip)))
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{
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size_t mlt = LZ4_count(ip+MINMATCH, match+MINMATCH, iLimit) + MINMATCH;
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if (mlt > ml) { ml = mlt; *matchpos = match; }
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}
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}
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else
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{
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match = dictBase + matchIndex;
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if (LZ4_read32(match) == LZ4_read32(ip))
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{
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size_t mlt;
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const BYTE* vLimit = ip + (dictLimit - matchIndex);
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if (vLimit > iLimit) vLimit = iLimit;
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mlt = LZ4_count(ip+MINMATCH, match+MINMATCH, vLimit) + MINMATCH;
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if ((ip+mlt == vLimit) && (vLimit < iLimit))
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mlt += LZ4_count(ip+mlt, base+dictLimit, iLimit);
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if (mlt > ml) { ml = mlt; *matchpos = base + matchIndex; } /* virtual matchpos */
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}
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}
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matchIndex -= chainTable[matchIndex & 0xFFFF];
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}
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return (int)ml;
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}
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FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch (
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LZ4HC_Data_Structure* hc4,
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const BYTE* const ip,
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const BYTE* const iLowLimit,
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const BYTE* const iHighLimit,
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int longest,
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const BYTE** matchpos,
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const BYTE** startpos,
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const int maxNbAttempts)
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{
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U16* const chainTable = hc4->chainTable;
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U32* const HashTable = hc4->hashTable;
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const BYTE* const base = hc4->base;
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const U32 dictLimit = hc4->dictLimit;
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const BYTE* const lowPrefixPtr = base + dictLimit;
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const U32 lowLimit = (hc4->lowLimit + 64 KB > (U32)(ip-base)) ? hc4->lowLimit : (U32)(ip - base) - (64 KB - 1);
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const BYTE* const dictBase = hc4->dictBase;
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U32 matchIndex;
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int nbAttempts = maxNbAttempts;
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int delta = (int)(ip-iLowLimit);
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/* First Match */
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LZ4HC_Insert(hc4, ip);
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matchIndex = HashTable[LZ4HC_hashPtr(ip)];
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while ((matchIndex>=lowLimit) && (nbAttempts))
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{
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nbAttempts--;
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if (matchIndex >= dictLimit)
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{
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const BYTE* matchPtr = base + matchIndex;
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if (*(iLowLimit + longest) == *(matchPtr - delta + longest))
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if (LZ4_read32(matchPtr) == LZ4_read32(ip))
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{
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int mlt = MINMATCH + LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit);
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int back = 0;
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while ((ip+back>iLowLimit)
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&& (matchPtr+back > lowPrefixPtr)
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&& (ip[back-1] == matchPtr[back-1]))
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back--;
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mlt -= back;
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if (mlt > longest)
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{
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longest = (int)mlt;
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*matchpos = matchPtr+back;
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*startpos = ip+back;
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}
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}
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}
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else
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{
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const BYTE* matchPtr = dictBase + matchIndex;
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if (LZ4_read32(matchPtr) == LZ4_read32(ip))
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{
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size_t mlt;
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int back=0;
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const BYTE* vLimit = ip + (dictLimit - matchIndex);
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if (vLimit > iHighLimit) vLimit = iHighLimit;
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mlt = LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH;
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if ((ip+mlt == vLimit) && (vLimit < iHighLimit))
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mlt += LZ4_count(ip+mlt, base+dictLimit, iHighLimit);
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while ((ip+back > iLowLimit) && (matchIndex+back > lowLimit) && (ip[back-1] == matchPtr[back-1])) back--;
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mlt -= back;
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if ((int)mlt > longest) { longest = (int)mlt; *matchpos = base + matchIndex + back; *startpos = ip+back; }
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}
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}
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matchIndex -= chainTable[matchIndex & 0xFFFF];
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}
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return longest;
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}
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typedef enum { noLimit = 0, limitedOutput = 1 } limitedOutput_directive;
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#define LZ4HC_DEBUG 0
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#if LZ4HC_DEBUG
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static unsigned debug = 0;
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#endif
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FORCE_INLINE int LZ4HC_encodeSequence (
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const BYTE** ip,
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BYTE** op,
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const BYTE** anchor,
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int matchLength,
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const BYTE* const match,
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limitedOutput_directive limitedOutputBuffer,
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BYTE* oend)
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{
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int length;
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BYTE* token;
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#if LZ4HC_DEBUG
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if (debug) printf("literal : %u -- match : %u -- offset : %u\n", (U32)(*ip - *anchor), (U32)matchLength, (U32)(*ip-match));
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#endif
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/* Encode Literal length */
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length = (int)(*ip - *anchor);
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token = (*op)++;
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if ((limitedOutputBuffer) && ((*op + (length>>8) + length + (2 + 1 + LASTLITERALS)) > oend)) return 1; /* Check output limit */
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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; }
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else *token = (BYTE)(length<<ML_BITS);
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/* Copy Literals */
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LZ4_wildCopy(*op, *anchor, (*op) + length);
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*op += length;
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/* Encode Offset */
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LZ4_writeLE16(*op, (U16)(*ip-match)); *op += 2;
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/* Encode MatchLength */
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length = (int)(matchLength-MINMATCH);
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if ((limitedOutputBuffer) && (*op + (length>>8) + (1 + LASTLITERALS) > oend)) return 1; /* Check output limit */
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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; }
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else *token += (BYTE)(length);
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/* Prepare next loop */
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*ip += matchLength;
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*anchor = *ip;
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return 0;
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}
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static int LZ4HC_compress_generic (
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void* ctxvoid,
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const char* source,
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char* dest,
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int inputSize,
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int maxOutputSize,
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int compressionLevel,
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limitedOutput_directive limit
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)
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{
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LZ4HC_Data_Structure* ctx = (LZ4HC_Data_Structure*) ctxvoid;
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const BYTE* ip = (const BYTE*) source;
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const BYTE* anchor = ip;
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const BYTE* const iend = ip + inputSize;
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const BYTE* const mflimit = iend - MFLIMIT;
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const BYTE* const matchlimit = (iend - LASTLITERALS);
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BYTE* op = (BYTE*) dest;
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BYTE* const oend = op + maxOutputSize;
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unsigned maxNbAttempts;
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int ml, ml2, ml3, ml0;
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const BYTE* ref=NULL;
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const BYTE* start2=NULL;
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const BYTE* ref2=NULL;
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const BYTE* start3=NULL;
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const BYTE* ref3=NULL;
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const BYTE* start0;
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const BYTE* ref0;
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/* init */
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if (compressionLevel > g_maxCompressionLevel) compressionLevel = g_maxCompressionLevel;
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if (compressionLevel < 1) compressionLevel = LZ4HC_compressionLevel_default;
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maxNbAttempts = 1 << (compressionLevel-1);
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ctx->end += inputSize;
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ip++;
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/* Main Loop */
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while (ip < mflimit)
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{
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ml = LZ4HC_InsertAndFindBestMatch (ctx, ip, matchlimit, (&ref), maxNbAttempts);
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if (!ml) { ip++; continue; }
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/* saved, in case we would skip too much */
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start0 = ip;
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ref0 = ref;
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ml0 = ml;
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_Search2:
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if (ip+ml < mflimit)
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ml2 = LZ4HC_InsertAndGetWiderMatch(ctx, ip + ml - 2, ip + 1, matchlimit, ml, &ref2, &start2, maxNbAttempts);
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else ml2 = ml;
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if (ml2 == ml) /* No better match */
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{
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if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) return 0;
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continue;
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}
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if (start0 < ip)
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{
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if (start2 < ip + ml0) /* empirical */
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{
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ip = start0;
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ref = ref0;
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ml = ml0;
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}
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}
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/* Here, start0==ip */
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if ((start2 - ip) < 3) /* First Match too small : removed */
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{
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ml = ml2;
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ip = start2;
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ref =ref2;
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goto _Search2;
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}
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_Search3:
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/*
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* Currently we have :
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* ml2 > ml1, and
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* ip1+3 <= ip2 (usually < ip1+ml1)
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*/
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if ((start2 - ip) < OPTIMAL_ML)
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{
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int correction;
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int new_ml = ml;
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if (new_ml > OPTIMAL_ML) new_ml = OPTIMAL_ML;
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if (ip+new_ml > start2 + ml2 - MINMATCH) new_ml = (int)(start2 - ip) + ml2 - MINMATCH;
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correction = new_ml - (int)(start2 - ip);
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if (correction > 0)
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{
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start2 += correction;
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ref2 += correction;
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ml2 -= correction;
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}
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}
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/* Now, we have start2 = ip+new_ml, with new_ml = min(ml, OPTIMAL_ML=18) */
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if (start2 + ml2 < mflimit)
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ml3 = LZ4HC_InsertAndGetWiderMatch(ctx, start2 + ml2 - 3, start2, matchlimit, ml2, &ref3, &start3, maxNbAttempts);
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else ml3 = ml2;
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if (ml3 == ml2) /* No better match : 2 sequences to encode */
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{
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/* ip & ref are known; Now for ml */
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if (start2 < ip+ml) ml = (int)(start2 - ip);
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/* Now, encode 2 sequences */
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if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) return 0;
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ip = start2;
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if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml2, ref2, limit, oend)) return 0;
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continue;
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}
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if (start3 < ip+ml+3) /* Not enough space for match 2 : remove it */
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{
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if (start3 >= (ip+ml)) /* can write Seq1 immediately ==> Seq2 is removed, so Seq3 becomes Seq1 */
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{
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if (start2 < ip+ml)
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{
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int correction = (int)(ip+ml - start2);
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start2 += correction;
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ref2 += correction;
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ml2 -= correction;
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if (ml2 < MINMATCH)
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{
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start2 = start3;
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ref2 = ref3;
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ml2 = ml3;
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}
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}
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if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) return 0;
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ip = start3;
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ref = ref3;
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ml = ml3;
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start0 = start2;
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ref0 = ref2;
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ml0 = ml2;
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goto _Search2;
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}
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start2 = start3;
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ref2 = ref3;
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ml2 = ml3;
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goto _Search3;
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}
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/*
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* OK, now we have 3 ascending matches; let's write at least the first one
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* ip & ref are known; Now for ml
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*/
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if (start2 < ip+ml)
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{
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if ((start2 - ip) < (int)ML_MASK)
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{
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int correction;
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if (ml > OPTIMAL_ML) ml = OPTIMAL_ML;
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if (ip + ml > start2 + ml2 - MINMATCH) ml = (int)(start2 - ip) + ml2 - MINMATCH;
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correction = ml - (int)(start2 - ip);
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if (correction > 0)
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{
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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); }
|
|
|
|
|
|
|
|
/**************************************
|
|
* 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* dictBegin = ctxPtr->dictBase + ctxPtr->lowLimit;
|
|
const BYTE* dictEnd = ctxPtr->dictBase + ctxPtr->dictLimit;
|
|
if ((sourceEnd > dictBegin) && ((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_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);
|
|
{
|
|
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;
|
|
if (streamPtr->nextToUpdate < streamPtr->dictLimit) streamPtr->nextToUpdate = streamPtr->dictLimit;
|
|
}
|
|
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;
|
|
int dictSize = LZ4_saveDictHC((LZ4_streamHC_t*)LZ4HC_Data, (char*)(hc4->inputBuffer), 64 KB);
|
|
return (char*)(hc4->inputBuffer + dictSize);
|
|
}
|