123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893 |
- /*
- LZ4 HC - High Compression Mode of LZ4
- Copyright (C) 2011-2017, 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
- */
- /* note : lz4hc is not an independent module, it requires lz4.h/lz4.c for proper compilation */
- /* *************************************
- * 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.
- */
- #ifndef LZ4HC_HEAPMODE
- # define LZ4HC_HEAPMODE 1
- #endif
- /*=== Dependency ===*/
- #define LZ4_HC_STATIC_LINKING_ONLY
- #include "lz4hc.h"
- /*=== Common LZ4 definitions ===*/
- #if defined(__GNUC__)
- # pragma GCC diagnostic ignored "-Wunused-function"
- #endif
- #if defined (__clang__)
- # pragma clang diagnostic ignored "-Wunused-function"
- #endif
- #define LZ4_COMMONDEFS_ONLY
- #include "lz4.c" /* LZ4_count, constants, mem */
- /*=== Constants ===*/
- #define OPTIMAL_ML (int)((ML_MASK-1)+MINMATCH)
- /*=== Macros ===*/
- #define MIN(a,b) ( (a) < (b) ? (a) : (b) )
- #define MAX(a,b) ( (a) > (b) ? (a) : (b) )
- #define HASH_FUNCTION(i) (((i) * 2654435761U) >> ((MINMATCH*8)-LZ4HC_HASH_LOG))
- #define DELTANEXTMAXD(p) chainTable[(p) & LZ4HC_MAXD_MASK] /* flexible, LZ4HC_MAXD dependent */
- #define DELTANEXTU16(table, pos) table[(U16)(pos)] /* faster */
- static U32 LZ4HC_hashPtr(const void* ptr) { return HASH_FUNCTION(LZ4_read32(ptr)); }
- /**************************************
- * HC Compression
- **************************************/
- static void LZ4HC_init (LZ4HC_CCtx_internal* 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) */
- LZ4_FORCE_INLINE void LZ4HC_Insert (LZ4HC_CCtx_internal* hc4, const BYTE* ip)
- {
- U16* const chainTable = hc4->chainTable;
- U32* const hashTable = hc4->hashTable;
- const BYTE* const base = hc4->base;
- U32 const target = (U32)(ip - base);
- 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(chainTable, idx) = (U16)delta;
- hashTable[h] = idx;
- idx++;
- }
- hc4->nextToUpdate = target;
- }
- /** LZ4HC_countBack() :
- * @return : negative value, nb of common bytes before ip/match */
- LZ4_FORCE_INLINE
- int LZ4HC_countBack(const BYTE* const ip, const BYTE* const match,
- const BYTE* const iMin, const BYTE* const mMin)
- {
- int back=0;
- while ( (ip+back > iMin)
- && (match+back > mMin)
- && (ip[back-1] == match[back-1]))
- back--;
- return back;
- }
- /* LZ4HC_countPattern() :
- * pattern32 must be a sample of repetitive pattern of length 1, 2 or 4 (but not 3!) */
- static unsigned LZ4HC_countPattern(const BYTE* ip, const BYTE* const iEnd, U32 const pattern32)
- {
- const BYTE* const iStart = ip;
- reg_t const pattern = (sizeof(pattern)==8) ? (reg_t)pattern32 + (((reg_t)pattern32) << 32) : pattern32;
- while (likely(ip < iEnd-(sizeof(pattern)-1))) {
- reg_t const diff = LZ4_read_ARCH(ip) ^ pattern;
- if (!diff) { ip+=sizeof(pattern); continue; }
- ip += LZ4_NbCommonBytes(diff);
- return (unsigned)(ip - iStart);
- }
- if (LZ4_isLittleEndian()) {
- reg_t patternByte = pattern;
- while ((ip<iEnd) && (*ip == (BYTE)patternByte)) {
- ip++; patternByte >>= 8;
- }
- } else { /* big endian */
- U32 bitOffset = (sizeof(pattern)*8) - 8;
- while (ip < iEnd) {
- BYTE const byte = (BYTE)(pattern >> bitOffset);
- if (*ip != byte) break;
- ip ++; bitOffset -= 8;
- }
- }
- return (unsigned)(ip - iStart);
- }
- /* LZ4HC_reverseCountPattern() :
- * pattern must be a sample of repetitive pattern of length 1, 2 or 4 (but not 3!)
- * read using natural platform endianess */
- static unsigned LZ4HC_reverseCountPattern(const BYTE* ip, const BYTE* const iLow, U32 pattern)
- {
- const BYTE* const iStart = ip;
- while (likely(ip >= iLow+4)) {
- if (LZ4_read32(ip-4) != pattern) break;
- ip -= 4;
- }
- { const BYTE* bytePtr = (const BYTE*)(&pattern) + 3; /* works for any endianess */
- while (likely(ip>iLow)) {
- if (ip[-1] != *bytePtr) break;
- ip--; bytePtr--;
- } }
- return (unsigned)(iStart - ip);
- }
- typedef enum { rep_untested, rep_not, rep_confirmed } repeat_state_e;
- LZ4_FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch (
- LZ4HC_CCtx_internal* hc4,
- const BYTE* const ip,
- const BYTE* const iLowLimit,
- const BYTE* const iHighLimit,
- int longest,
- const BYTE** matchpos,
- const BYTE** startpos,
- const int maxNbAttempts,
- const int patternAnalysis)
- {
- 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) - MAX_DISTANCE;
- const BYTE* const dictBase = hc4->dictBase;
- int const delta = (int)(ip-iLowLimit);
- int nbAttempts = maxNbAttempts;
- U32 const pattern = LZ4_read32(ip);
- U32 matchIndex;
- repeat_state_e repeat = rep_untested;
- size_t srcPatternLength = 0;
- DEBUGLOG(7, "LZ4HC_InsertAndGetWiderMatch");
- /* First Match */
- LZ4HC_Insert(hc4, ip);
- matchIndex = HashTable[LZ4HC_hashPtr(ip)];
- DEBUGLOG(7, "First match at index %u / %u (lowLimit)",
- matchIndex, lowLimit);
- while ((matchIndex>=lowLimit) && (nbAttempts)) {
- DEBUGLOG(7, "remaining attempts : %i", nbAttempts);
- nbAttempts--;
- if (matchIndex >= dictLimit) {
- const BYTE* const matchPtr = base + matchIndex;
- if (*(iLowLimit + longest) == *(matchPtr - delta + longest)) {
- if (LZ4_read32(matchPtr) == pattern) {
- int mlt = MINMATCH + LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit);
- #if 0
- /* more generic but unfortunately slower on clang */
- int const back = LZ4HC_countBack(ip, matchPtr, iLowLimit, lowPrefixPtr);
- #else
- int back = 0;
- while ( (ip+back > iLowLimit)
- && (matchPtr+back > lowPrefixPtr)
- && (ip[back-1] == matchPtr[back-1])) {
- back--;
- }
- #endif
- mlt -= back;
- if (mlt > longest) {
- longest = mlt;
- *matchpos = matchPtr+back;
- *startpos = ip+back;
- } }
- }
- } else { /* matchIndex < dictLimit */
- const BYTE* const matchPtr = dictBase + matchIndex;
- if (LZ4_read32(matchPtr) == pattern) {
- int 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 (mlt > longest) {
- longest = mlt;
- *matchpos = base + matchIndex + back;
- *startpos = ip + back;
- } } }
- { U32 const nextOffset = DELTANEXTU16(chainTable, matchIndex);
- matchIndex -= nextOffset;
- if (patternAnalysis && nextOffset==1) {
- /* may be a repeated pattern */
- if (repeat == rep_untested) {
- if ( ((pattern & 0xFFFF) == (pattern >> 16))
- & ((pattern & 0xFF) == (pattern >> 24)) ) {
- repeat = rep_confirmed;
- srcPatternLength = LZ4HC_countPattern(ip+4, iHighLimit, pattern) + 4;
- } else {
- repeat = rep_not;
- } }
- if ( (repeat == rep_confirmed)
- && (matchIndex >= dictLimit) ) { /* same segment only */
- const BYTE* const matchPtr = base + matchIndex;
- if (LZ4_read32(matchPtr) == pattern) { /* good candidate */
- size_t const forwardPatternLength = LZ4HC_countPattern(matchPtr+sizeof(pattern), iHighLimit, pattern) + sizeof(pattern);
- const BYTE* const maxLowPtr = (lowPrefixPtr + MAX_DISTANCE >= ip) ? lowPrefixPtr : ip - MAX_DISTANCE;
- size_t const backLength = LZ4HC_reverseCountPattern(matchPtr, maxLowPtr, pattern);
- size_t const currentSegmentLength = backLength + forwardPatternLength;
- if ( (currentSegmentLength >= srcPatternLength) /* current pattern segment large enough to contain full srcPatternLength */
- && (forwardPatternLength <= srcPatternLength) ) { /* haven't reached this position yet */
- matchIndex += (U32)forwardPatternLength - (U32)srcPatternLength; /* best position, full pattern, might be followed by more match */
- } else {
- matchIndex -= (U32)backLength; /* let's go to farthest segment position, will find a match of length currentSegmentLength + maybe some back */
- }
- } } } }
- } /* while ((matchIndex>=lowLimit) && (nbAttempts)) */
- return longest;
- }
- LZ4_FORCE_INLINE
- int LZ4HC_InsertAndFindBestMatch(LZ4HC_CCtx_internal* const hc4, /* Index table will be updated */
- const BYTE* const ip, const BYTE* const iLimit,
- const BYTE** matchpos,
- const int maxNbAttempts,
- const int patternAnalysis)
- {
- const BYTE* uselessPtr = ip;
- /* note : LZ4HC_InsertAndGetWiderMatch() is able to modify the starting position of a match (*startpos),
- * but this won't be the case here, as we define iLowLimit==ip,
- * so LZ4HC_InsertAndGetWiderMatch() won't be allowed to search past ip */
- return LZ4HC_InsertAndGetWiderMatch(hc4, ip, ip, iLimit, MINMATCH-1, matchpos, &uselessPtr, maxNbAttempts, patternAnalysis);
- }
- typedef enum {
- noLimit = 0,
- limitedOutput = 1,
- limitedDestSize = 2,
- } limitedOutput_directive;
- /* LZ4HC_encodeSequence() :
- * @return : 0 if ok,
- * 1 if buffer issue detected */
- LZ4_FORCE_INLINE int LZ4HC_encodeSequence (
- const BYTE** ip,
- BYTE** op,
- const BYTE** anchor,
- int matchLength,
- const BYTE* const match,
- limitedOutput_directive limit,
- BYTE* oend)
- {
- size_t length;
- BYTE* const token = (*op)++;
- #if defined(LZ4_DEBUG) && (LZ4_DEBUG >= 2)
- static const BYTE* start = NULL;
- static U32 totalCost = 0;
- U32 const pos = (start==NULL) ? 0 : (U32)(*anchor - start);
- U32 const ll = (U32)(*ip - *anchor);
- U32 const llAdd = (ll>=15) ? ((ll-15) / 255) + 1 : 0;
- U32 const mlAdd = (matchLength>=19) ? ((matchLength-19) / 255) + 1 : 0;
- U32 const cost = 1 + llAdd + ll + 2 + mlAdd;
- if (start==NULL) start = *anchor; /* only works for single segment */
- //g_debuglog_enable = (pos >= 2228) & (pos <= 2262);
- DEBUGLOG(2, "pos:%7u -- literals:%3u, match:%4i, offset:%5u, cost:%3u + %u",
- pos,
- (U32)(*ip - *anchor), matchLength, (U32)(*ip-match),
- cost, totalCost);
- totalCost += cost;
- #endif
- /* Encode Literal length */
- length = (size_t)(*ip - *anchor);
- if ((limit) && ((*op + (length >> 8) + length + (2 + 1 + LASTLITERALS)) > oend)) return 1; /* Check output limit */
- if (length >= RUN_MASK) {
- size_t len = length - RUN_MASK;
- *token = (RUN_MASK << ML_BITS);
- for(; len >= 255 ; len -= 255) *(*op)++ = 255;
- *(*op)++ = (BYTE)len;
- } 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 */
- assert(matchLength >= MINMATCH);
- length = (size_t)(matchLength - MINMATCH);
- if ((limit) && (*op + (length >> 8) + (1 + LASTLITERALS) > oend)) return 1; /* Check output limit */
- if (length >= ML_MASK) {
- *token += ML_MASK;
- length -= ML_MASK;
- for(; length >= 510 ; length -= 510) { *(*op)++ = 255; *(*op)++ = 255; }
- if (length >= 255) { length -= 255; *(*op)++ = 255; }
- *(*op)++ = (BYTE)length;
- } else {
- *token += (BYTE)(length);
- }
- /* Prepare next loop */
- *ip += matchLength;
- *anchor = *ip;
- return 0;
- }
- /* btopt */
- #include "lz4opt.h"
- static int LZ4HC_compress_hashChain (
- LZ4HC_CCtx_internal* const ctx,
- const char* const source,
- char* const dest,
- int* srcSizePtr,
- int const maxOutputSize,
- unsigned maxNbAttempts,
- limitedOutput_directive limit
- )
- {
- const int inputSize = *srcSizePtr;
- const int patternAnalysis = (maxNbAttempts > 64); /* levels 8+ */
- 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* optr = (BYTE*) dest;
- BYTE* op = (BYTE*) dest;
- BYTE* oend = op + maxOutputSize;
- 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 */
- *srcSizePtr = 0;
- if (limit == limitedDestSize) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */
- if (inputSize < LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */
- /* Main Loop */
- while (ip < mflimit) {
- ml = LZ4HC_InsertAndFindBestMatch (ctx, ip, matchlimit, &ref, maxNbAttempts, patternAnalysis);
- if (ml<MINMATCH) { 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 + 0, matchlimit, ml, &ref2, &start2,
- maxNbAttempts, patternAnalysis);
- else
- ml2 = ml;
- if (ml2 == ml) { /* No better match */
- optr = op;
- if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow;
- 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:
- /* At this stage, 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, patternAnalysis);
- 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 */
- optr = op;
- if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow;
- ip = start2;
- optr = op;
- if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml2, ref2, limit, oend)) goto _dest_overflow;
- 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;
- }
- }
- optr = op;
- if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow;
- 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);
- }
- }
- optr = op;
- if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow;
- ip = start2;
- ref = ref2;
- ml = ml2;
- start2 = start3;
- ref2 = ref3;
- ml2 = ml3;
- goto _Search3;
- }
- _last_literals:
- /* Encode Last Literals */
- { size_t lastRunSize = (size_t)(iend - anchor); /* literals */
- size_t litLength = (lastRunSize + 255 - RUN_MASK) / 255;
- size_t const totalSize = 1 + litLength + lastRunSize;
- if (limit == limitedDestSize) oend += LASTLITERALS; /* restore correct value */
- if (limit && (op + totalSize > oend)) {
- if (limit == limitedOutput) return 0; /* Check output limit */
- /* adapt lastRunSize to fill 'dest' */
- lastRunSize = (size_t)(oend - op) - 1;
- litLength = (lastRunSize + 255 - RUN_MASK) / 255;
- lastRunSize -= litLength;
- }
- ip = anchor + lastRunSize;
- if (lastRunSize >= RUN_MASK) {
- size_t accumulator = lastRunSize - RUN_MASK;
- *op++ = (RUN_MASK << ML_BITS);
- for(; accumulator >= 255 ; accumulator -= 255) *op++ = 255;
- *op++ = (BYTE) accumulator;
- } else {
- *op++ = (BYTE)(lastRunSize << ML_BITS);
- }
- memcpy(op, anchor, lastRunSize);
- op += lastRunSize;
- }
- /* End */
- *srcSizePtr = (int) (((const char*)ip) - source);
- return (int) (((char*)op)-dest);
- _dest_overflow:
- if (limit == limitedDestSize) {
- op = optr; /* restore correct out pointer */
- goto _last_literals;
- }
- return 0;
- }
- static int LZ4HC_compress_generic (
- LZ4HC_CCtx_internal* const ctx,
- const char* const src,
- char* const dst,
- int* const srcSizePtr,
- int const dstCapacity,
- int cLevel,
- limitedOutput_directive limit
- )
- {
- typedef enum { lz4hc, lz4opt } lz4hc_strat_e;
- typedef struct {
- lz4hc_strat_e strat;
- U32 nbSearches;
- U32 targetLength;
- } cParams_t;
- static const cParams_t clTable[LZ4HC_CLEVEL_MAX+1] = {
- { lz4hc, 2, 16 }, /* 0, unused */
- { lz4hc, 2, 16 }, /* 1, unused */
- { lz4hc, 2, 16 }, /* 2, unused */
- { lz4hc, 4, 16 }, /* 3 */
- { lz4hc, 8, 16 }, /* 4 */
- { lz4hc, 16, 16 }, /* 5 */
- { lz4hc, 32, 16 }, /* 6 */
- { lz4hc, 64, 16 }, /* 7 */
- { lz4hc, 128, 16 }, /* 8 */
- { lz4hc, 256, 16 }, /* 9 */
- { lz4opt, 96, 64 }, /*10==LZ4HC_CLEVEL_OPT_MIN*/
- { lz4opt, 512,128 }, /*11 */
- { lz4opt,8192, LZ4_OPT_NUM }, /* 12==LZ4HC_CLEVEL_MAX */
- };
- if (limit == limitedDestSize && dstCapacity < 1) return 0; /* Impossible to store anything */
- if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size (too large or negative) */
- ctx->end += *srcSizePtr;
- if (cLevel < 1) cLevel = LZ4HC_CLEVEL_DEFAULT; /* note : convention is different from lz4frame, maybe something to review */
- cLevel = MIN(LZ4HC_CLEVEL_MAX, cLevel);
- assert(cLevel >= 0);
- assert(cLevel <= LZ4HC_CLEVEL_MAX);
- { cParams_t const cParam = clTable[cLevel];
- if (cParam.strat == lz4hc)
- return LZ4HC_compress_hashChain(ctx,
- src, dst, srcSizePtr, dstCapacity,
- cParam.nbSearches, limit);
- assert(cParam.strat == lz4opt);
- return LZ4HC_compress_optimal(ctx,
- src, dst, srcSizePtr, dstCapacity,
- cParam.nbSearches, cParam.targetLength, limit,
- cLevel == LZ4HC_CLEVEL_MAX); /* ultra mode */
- }
- }
- int LZ4_sizeofStateHC(void) { return sizeof(LZ4_streamHC_t); }
- int LZ4_compress_HC_extStateHC (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
- {
- LZ4HC_CCtx_internal* const ctx = &((LZ4_streamHC_t*)state)->internal_donotuse;
- if (((size_t)(state)&(sizeof(void*)-1)) != 0) return 0; /* Error : state is not aligned for pointers (32 or 64 bits) */
- LZ4HC_init (ctx, (const BYTE*)src);
- if (dstCapacity < LZ4_compressBound(srcSize))
- return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, limitedOutput);
- else
- return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, noLimit);
- }
- int LZ4_compress_HC(const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
- {
- #if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1
- LZ4_streamHC_t* const statePtr = (LZ4_streamHC_t*)malloc(sizeof(LZ4_streamHC_t));
- #else
- LZ4_streamHC_t state;
- LZ4_streamHC_t* const statePtr = &state;
- #endif
- int const cSize = LZ4_compress_HC_extStateHC(statePtr, src, dst, srcSize, dstCapacity, compressionLevel);
- #if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1
- free(statePtr);
- #endif
- return cSize;
- }
- /* LZ4_compress_HC_destSize() :
- * only compatible with regular HC parser */
- int LZ4_compress_HC_destSize(void* LZ4HC_Data, const char* source, char* dest, int* sourceSizePtr, int targetDestSize, int cLevel)
- {
- LZ4HC_CCtx_internal* const ctx = &((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse;
- LZ4HC_init(ctx, (const BYTE*) source);
- return LZ4HC_compress_generic(ctx, source, dest, sourceSizePtr, targetDestSize, cLevel, limitedDestSize);
- }
- /**************************************
- * 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) {
- if (!LZ4_streamHCPtr) return 0; /* support free on NULL */
- free(LZ4_streamHCPtr);
- return 0;
- }
- /* initialization */
- void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
- {
- LZ4_STATIC_ASSERT(sizeof(LZ4HC_CCtx_internal) <= sizeof(size_t) * LZ4_STREAMHCSIZE_SIZET); /* if compilation fails here, LZ4_STREAMHCSIZE must be increased */
- LZ4_streamHCPtr->internal_donotuse.base = NULL;
- LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel);
- }
- void LZ4_setCompressionLevel(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
- {
- if (compressionLevel < 1) compressionLevel = 1;
- if (compressionLevel > LZ4HC_CLEVEL_MAX) compressionLevel = LZ4HC_CLEVEL_MAX;
- LZ4_streamHCPtr->internal_donotuse.compressionLevel = compressionLevel;
- }
- int LZ4_loadDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, const char* dictionary, int dictSize)
- {
- LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
- if (dictSize > 64 KB) {
- dictionary += dictSize - 64 KB;
- dictSize = 64 KB;
- }
- LZ4HC_init (ctxPtr, (const BYTE*)dictionary);
- ctxPtr->end = (const BYTE*)dictionary + dictSize;
- if (dictSize >= 4) LZ4HC_Insert (ctxPtr, ctxPtr->end-3);
- return dictSize;
- }
- /* compression */
- static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* 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 (LZ4_streamHC_t* LZ4_streamHCPtr,
- const char* src, char* dst,
- int* srcSizePtr, int dstCapacity,
- limitedOutput_directive limit)
- {
- LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
- /* auto-init if forgotten */
- if (ctxPtr->base == NULL) LZ4HC_init (ctxPtr, (const BYTE*) src);
- /* Check overflow */
- if ((size_t)(ctxPtr->end - ctxPtr->base) > 2 GB) {
- size_t dictSize = (size_t)(ctxPtr->end - ctxPtr->base) - ctxPtr->dictLimit;
- if (dictSize > 64 KB) dictSize = 64 KB;
- LZ4_loadDictHC(LZ4_streamHCPtr, (const char*)(ctxPtr->end) - dictSize, (int)dictSize);
- }
- /* Check if blocks follow each other */
- if ((const BYTE*)src != ctxPtr->end) LZ4HC_setExternalDict(ctxPtr, (const BYTE*)src);
- /* Check overlapping input/dictionary space */
- { const BYTE* sourceEnd = (const BYTE*) src + *srcSizePtr;
- const BYTE* const dictBegin = ctxPtr->dictBase + ctxPtr->lowLimit;
- const BYTE* const dictEnd = ctxPtr->dictBase + ctxPtr->dictLimit;
- if ((sourceEnd > dictBegin) && ((const BYTE*)src < dictEnd)) {
- if (sourceEnd > dictEnd) sourceEnd = dictEnd;
- ctxPtr->lowLimit = (U32)(sourceEnd - ctxPtr->dictBase);
- if (ctxPtr->dictLimit - ctxPtr->lowLimit < 4) ctxPtr->lowLimit = ctxPtr->dictLimit;
- }
- }
- return LZ4HC_compress_generic (ctxPtr, src, dst, srcSizePtr, dstCapacity, ctxPtr->compressionLevel, limit);
- }
- int LZ4_compress_HC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* src, char* dst, int srcSize, int dstCapacity)
- {
- if (dstCapacity < LZ4_compressBound(srcSize))
- return LZ4_compressHC_continue_generic (LZ4_streamHCPtr, src, dst, &srcSize, dstCapacity, limitedOutput);
- else
- return LZ4_compressHC_continue_generic (LZ4_streamHCPtr, src, dst, &srcSize, dstCapacity, noLimit);
- }
- int LZ4_compress_HC_continue_destSize (LZ4_streamHC_t* LZ4_streamHCPtr, const char* src, char* dst, int* srcSizePtr, int targetDestSize)
- {
- return LZ4_compressHC_continue_generic(LZ4_streamHCPtr, src, dst, srcSizePtr, targetDestSize, limitedDestSize);
- }
- /* dictionary saving */
- int LZ4_saveDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, char* safeBuffer, int dictSize)
- {
- LZ4HC_CCtx_internal* const streamPtr = &LZ4_streamHCPtr->internal_donotuse;
- int const prefixSize = (int)(streamPtr->end - (streamPtr->base + streamPtr->dictLimit));
- 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
- ***********************************/
- /* These functions currently generate deprecation warnings */
- /* Deprecated compression functions */
- int LZ4_compressHC(const char* src, char* dst, int srcSize) { return LZ4_compress_HC (src, dst, srcSize, LZ4_compressBound(srcSize), 0); }
- int LZ4_compressHC_limitedOutput(const char* src, char* dst, int srcSize, int maxDstSize) { return LZ4_compress_HC(src, dst, srcSize, maxDstSize, 0); }
- int LZ4_compressHC2(const char* src, char* dst, int srcSize, int cLevel) { return LZ4_compress_HC (src, dst, srcSize, LZ4_compressBound(srcSize), cLevel); }
- 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 */
- int LZ4_sizeofStreamStateHC(void) { return LZ4_STREAMHCSIZE; }
- int LZ4_resetStreamStateHC(void* state, char* inputBuffer)
- {
- LZ4HC_CCtx_internal *ctx = &((LZ4_streamHC_t*)state)->internal_donotuse;
- if ((((size_t)state) & (sizeof(void*)-1)) != 0) return 1; /* Error : pointer is not aligned for pointer (32 or 64 bits) */
- LZ4HC_init(ctx, (const BYTE*)inputBuffer);
- ctx->inputBuffer = (BYTE*)inputBuffer;
- return 0;
- }
- void* LZ4_createHC (char* inputBuffer)
- {
- LZ4_streamHC_t* hc4 = (LZ4_streamHC_t*)ALLOCATOR(1, sizeof(LZ4_streamHC_t));
- if (hc4 == NULL) return NULL; /* not enough memory */
- LZ4HC_init (&hc4->internal_donotuse, (const BYTE*)inputBuffer);
- hc4->internal_donotuse.inputBuffer = (BYTE*)inputBuffer;
- return hc4;
- }
- int LZ4_freeHC (void* LZ4HC_Data) {
- if (!LZ4HC_Data) return 0; /* support free on NULL */
- FREEMEM(LZ4HC_Data);
- return 0;
- }
- int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* src, char* dst, int srcSize, int cLevel)
- {
- return LZ4HC_compress_generic (&((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse, src, dst, &srcSize, 0, cLevel, noLimit);
- }
- int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* src, char* dst, int srcSize, int dstCapacity, int cLevel)
- {
- return LZ4HC_compress_generic (&((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse, src, dst, &srcSize, dstCapacity, cLevel, limitedOutput);
- }
- char* LZ4_slideInputBufferHC(void* LZ4HC_Data)
- {
- LZ4HC_CCtx_internal* const hc4 = &((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse;
- int const dictSize = LZ4_saveDictHC((LZ4_streamHC_t*)LZ4HC_Data, (char*)(hc4->inputBuffer), 64 KB);
- return (char*)(hc4->inputBuffer + dictSize);
- }
|