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-rw-r--r--mfbt/lz4/lz4hc.c1631
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diff --git a/mfbt/lz4/lz4hc.c b/mfbt/lz4/lz4hc.c
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+/*
+ LZ4 HC - High Compression Mode of LZ4
+ Copyright (C) 2011-2020, 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 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
+#ifndef LZ4_SRC_INCLUDED
+#include "lz4.c" /* LZ4_count, constants, mem */
+#endif
+
+
+/*=== Enums ===*/
+typedef enum { noDictCtx, usingDictCtxHc } dictCtx_directive;
+
+
+/*=== Constants ===*/
+#define OPTIMAL_ML (int)((ML_MASK-1)+MINMATCH)
+#define LZ4_OPT_NUM (1<<12)
+
+
+/*=== 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 */
+/* Make fields passed to, and updated by LZ4HC_encodeSequence explicit */
+#define UPDATABLE(ip, op, anchor) &ip, &op, &anchor
+
+static U32 LZ4HC_hashPtr(const void* ptr) { return HASH_FUNCTION(LZ4_read32(ptr)); }
+
+
+/**************************************
+* HC Compression
+**************************************/
+static void LZ4HC_clearTables (LZ4HC_CCtx_internal* hc4)
+{
+ MEM_INIT(hc4->hashTable, 0, sizeof(hc4->hashTable));
+ MEM_INIT(hc4->chainTable, 0xFF, sizeof(hc4->chainTable));
+}
+
+static void LZ4HC_init_internal (LZ4HC_CCtx_internal* hc4, const BYTE* start)
+{
+ size_t const bufferSize = (size_t)(hc4->end - hc4->prefixStart);
+ size_t newStartingOffset = bufferSize + hc4->dictLimit;
+ assert(newStartingOffset >= bufferSize); /* check overflow */
+ if (newStartingOffset > 1 GB) {
+ LZ4HC_clearTables(hc4);
+ newStartingOffset = 0;
+ }
+ newStartingOffset += 64 KB;
+ hc4->nextToUpdate = (U32)newStartingOffset;
+ hc4->prefixStart = start;
+ hc4->end = start;
+ hc4->dictStart = start;
+ hc4->dictLimit = (U32)newStartingOffset;
+ hc4->lowLimit = (U32)newStartingOffset;
+}
+
+
+/* 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 prefixPtr = hc4->prefixStart;
+ U32 const prefixIdx = hc4->dictLimit;
+ U32 const target = (U32)(ip - prefixPtr) + prefixIdx;
+ U32 idx = hc4->nextToUpdate;
+ assert(ip >= prefixPtr);
+ assert(target >= prefixIdx);
+
+ while (idx < target) {
+ U32 const h = LZ4HC_hashPtr(prefixPtr+idx-prefixIdx);
+ size_t delta = idx - hashTable[h];
+ if (delta>LZ4_DISTANCE_MAX) delta = LZ4_DISTANCE_MAX;
+ 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;
+ int const min = (int)MAX(iMin - ip, mMin - match);
+ assert(min <= 0);
+ assert(ip >= iMin); assert((size_t)(ip-iMin) < (1U<<31));
+ assert(match >= mMin); assert((size_t)(match - mMin) < (1U<<31));
+ while ( (back > min)
+ && (ip[back-1] == match[back-1]) )
+ back--;
+ return back;
+}
+
+#if defined(_MSC_VER)
+# define LZ4HC_rotl32(x,r) _rotl(x,r)
+#else
+# define LZ4HC_rotl32(x,r) ((x << r) | (x >> (32 - r)))
+#endif
+
+
+static U32 LZ4HC_rotatePattern(size_t const rotate, U32 const pattern)
+{
+ size_t const bitsToRotate = (rotate & (sizeof(pattern) - 1)) << 3;
+ if (bitsToRotate == 0) return pattern;
+ return LZ4HC_rotl32(pattern, (int)bitsToRotate);
+}
+
+/* LZ4HC_countPattern() :
+ * pattern32 must be a sample of repetitive pattern of length 1, 2 or 4 (but not 3!) */
+static unsigned
+LZ4HC_countPattern(const BYTE* ip, const BYTE* const iEnd, U32 const pattern32)
+{
+ const BYTE* const iStart = ip;
+ reg_t const pattern = (sizeof(pattern)==8) ?
+ (reg_t)pattern32 + (((reg_t)pattern32) << (sizeof(pattern)*4)) : 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 endianness */
+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 endianness */
+ while (likely(ip>iLow)) {
+ if (ip[-1] != *bytePtr) break;
+ ip--; bytePtr--;
+ } }
+ return (unsigned)(iStart - ip);
+}
+
+/* LZ4HC_protectDictEnd() :
+ * Checks if the match is in the last 3 bytes of the dictionary, so reading the
+ * 4 byte MINMATCH would overflow.
+ * @returns true if the match index is okay.
+ */
+static int LZ4HC_protectDictEnd(U32 const dictLimit, U32 const matchIndex)
+{
+ return ((U32)((dictLimit - 1) - matchIndex) >= 3);
+}
+
+typedef enum { rep_untested, rep_not, rep_confirmed } repeat_state_e;
+typedef enum { favorCompressionRatio=0, favorDecompressionSpeed } HCfavor_e;
+
+LZ4_FORCE_INLINE int
+LZ4HC_InsertAndGetWiderMatch (
+ LZ4HC_CCtx_internal* const 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, const int chainSwap,
+ const dictCtx_directive dict,
+ const HCfavor_e favorDecSpeed)
+{
+ U16* const chainTable = hc4->chainTable;
+ U32* const HashTable = hc4->hashTable;
+ const LZ4HC_CCtx_internal * const dictCtx = hc4->dictCtx;
+ const BYTE* const prefixPtr = hc4->prefixStart;
+ const U32 prefixIdx = hc4->dictLimit;
+ const U32 ipIndex = (U32)(ip - prefixPtr) + prefixIdx;
+ const int withinStartDistance = (hc4->lowLimit + (LZ4_DISTANCE_MAX + 1) > ipIndex);
+ const U32 lowestMatchIndex = (withinStartDistance) ? hc4->lowLimit : ipIndex - LZ4_DISTANCE_MAX;
+ const BYTE* const dictStart = hc4->dictStart;
+ const U32 dictIdx = hc4->lowLimit;
+ const BYTE* const dictEnd = dictStart + prefixIdx - dictIdx;
+ int const lookBackLength = (int)(ip-iLowLimit);
+ int nbAttempts = maxNbAttempts;
+ U32 matchChainPos = 0;
+ 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 (lowestMatchIndex)",
+ matchIndex, lowestMatchIndex);
+
+ while ((matchIndex>=lowestMatchIndex) && (nbAttempts>0)) {
+ int matchLength=0;
+ nbAttempts--;
+ assert(matchIndex < ipIndex);
+ if (favorDecSpeed && (ipIndex - matchIndex < 8)) {
+ /* do nothing */
+ } else if (matchIndex >= prefixIdx) { /* within current Prefix */
+ const BYTE* const matchPtr = prefixPtr + matchIndex - prefixIdx;
+ assert(matchPtr < ip);
+ assert(longest >= 1);
+ if (LZ4_read16(iLowLimit + longest - 1) == LZ4_read16(matchPtr - lookBackLength + longest - 1)) {
+ if (LZ4_read32(matchPtr) == pattern) {
+ int const back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, prefixPtr) : 0;
+ matchLength = MINMATCH + (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit);
+ matchLength -= back;
+ if (matchLength > longest) {
+ longest = matchLength;
+ *matchpos = matchPtr + back;
+ *startpos = ip + back;
+ } } }
+ } else { /* lowestMatchIndex <= matchIndex < dictLimit */
+ const BYTE* const matchPtr = dictStart + (matchIndex - dictIdx);
+ assert(matchIndex >= dictIdx);
+ if ( likely(matchIndex <= prefixIdx - 4)
+ && (LZ4_read32(matchPtr) == pattern) ) {
+ int back = 0;
+ const BYTE* vLimit = ip + (prefixIdx - matchIndex);
+ if (vLimit > iHighLimit) vLimit = iHighLimit;
+ matchLength = (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH;
+ if ((ip+matchLength == vLimit) && (vLimit < iHighLimit))
+ matchLength += LZ4_count(ip+matchLength, prefixPtr, iHighLimit);
+ back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictStart) : 0;
+ matchLength -= back;
+ if (matchLength > longest) {
+ longest = matchLength;
+ *matchpos = prefixPtr - prefixIdx + matchIndex + back; /* virtual pos, relative to ip, to retrieve offset */
+ *startpos = ip + back;
+ } } }
+
+ if (chainSwap && matchLength==longest) { /* better match => select a better chain */
+ assert(lookBackLength==0); /* search forward only */
+ if (matchIndex + (U32)longest <= ipIndex) {
+ int const kTrigger = 4;
+ U32 distanceToNextMatch = 1;
+ int const end = longest - MINMATCH + 1;
+ int step = 1;
+ int accel = 1 << kTrigger;
+ int pos;
+ for (pos = 0; pos < end; pos += step) {
+ U32 const candidateDist = DELTANEXTU16(chainTable, matchIndex + (U32)pos);
+ step = (accel++ >> kTrigger);
+ if (candidateDist > distanceToNextMatch) {
+ distanceToNextMatch = candidateDist;
+ matchChainPos = (U32)pos;
+ accel = 1 << kTrigger;
+ } }
+ if (distanceToNextMatch > 1) {
+ if (distanceToNextMatch > matchIndex) break; /* avoid overflow */
+ matchIndex -= distanceToNextMatch;
+ continue;
+ } } }
+
+ { U32 const distNextMatch = DELTANEXTU16(chainTable, matchIndex);
+ if (patternAnalysis && distNextMatch==1 && matchChainPos==0) {
+ U32 const matchCandidateIdx = matchIndex-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+sizeof(pattern), iHighLimit, pattern) + sizeof(pattern);
+ } else {
+ repeat = rep_not;
+ } }
+ if ( (repeat == rep_confirmed) && (matchCandidateIdx >= lowestMatchIndex)
+ && LZ4HC_protectDictEnd(prefixIdx, matchCandidateIdx) ) {
+ const int extDict = matchCandidateIdx < prefixIdx;
+ const BYTE* const matchPtr = (extDict ? dictStart - dictIdx : prefixPtr - prefixIdx) + matchCandidateIdx;
+ if (LZ4_read32(matchPtr) == pattern) { /* good candidate */
+ const BYTE* const iLimit = extDict ? dictEnd : iHighLimit;
+ size_t forwardPatternLength = LZ4HC_countPattern(matchPtr+sizeof(pattern), iLimit, pattern) + sizeof(pattern);
+ if (extDict && matchPtr + forwardPatternLength == iLimit) {
+ U32 const rotatedPattern = LZ4HC_rotatePattern(forwardPatternLength, pattern);
+ forwardPatternLength += LZ4HC_countPattern(prefixPtr, iHighLimit, rotatedPattern);
+ }
+ { const BYTE* const lowestMatchPtr = extDict ? dictStart : prefixPtr;
+ size_t backLength = LZ4HC_reverseCountPattern(matchPtr, lowestMatchPtr, pattern);
+ size_t currentSegmentLength;
+ if (!extDict
+ && matchPtr - backLength == prefixPtr
+ && dictIdx < prefixIdx) {
+ U32 const rotatedPattern = LZ4HC_rotatePattern((U32)(-(int)backLength), pattern);
+ backLength += LZ4HC_reverseCountPattern(dictEnd, dictStart, rotatedPattern);
+ }
+ /* Limit backLength not go further than lowestMatchIndex */
+ backLength = matchCandidateIdx - MAX(matchCandidateIdx - (U32)backLength, lowestMatchIndex);
+ assert(matchCandidateIdx - backLength >= lowestMatchIndex);
+ currentSegmentLength = backLength + forwardPatternLength;
+ /* Adjust to end of pattern if the source pattern fits, otherwise the beginning of the pattern */
+ if ( (currentSegmentLength >= srcPatternLength) /* current pattern segment large enough to contain full srcPatternLength */
+ && (forwardPatternLength <= srcPatternLength) ) { /* haven't reached this position yet */
+ U32 const newMatchIndex = matchCandidateIdx + (U32)forwardPatternLength - (U32)srcPatternLength; /* best position, full pattern, might be followed by more match */
+ if (LZ4HC_protectDictEnd(prefixIdx, newMatchIndex))
+ matchIndex = newMatchIndex;
+ else {
+ /* Can only happen if started in the prefix */
+ assert(newMatchIndex >= prefixIdx - 3 && newMatchIndex < prefixIdx && !extDict);
+ matchIndex = prefixIdx;
+ }
+ } else {
+ U32 const newMatchIndex = matchCandidateIdx - (U32)backLength; /* farthest position in current segment, will find a match of length currentSegmentLength + maybe some back */
+ if (!LZ4HC_protectDictEnd(prefixIdx, newMatchIndex)) {
+ assert(newMatchIndex >= prefixIdx - 3 && newMatchIndex < prefixIdx && !extDict);
+ matchIndex = prefixIdx;
+ } else {
+ matchIndex = newMatchIndex;
+ if (lookBackLength==0) { /* no back possible */
+ size_t const maxML = MIN(currentSegmentLength, srcPatternLength);
+ if ((size_t)longest < maxML) {
+ assert(prefixPtr - prefixIdx + matchIndex != ip);
+ if ((size_t)(ip - prefixPtr) + prefixIdx - matchIndex > LZ4_DISTANCE_MAX) break;
+ assert(maxML < 2 GB);
+ longest = (int)maxML;
+ *matchpos = prefixPtr - prefixIdx + matchIndex; /* virtual pos, relative to ip, to retrieve offset */
+ *startpos = ip;
+ }
+ { U32 const distToNextPattern = DELTANEXTU16(chainTable, matchIndex);
+ if (distToNextPattern > matchIndex) break; /* avoid overflow */
+ matchIndex -= distToNextPattern;
+ } } } } }
+ continue;
+ } }
+ } } /* PA optimization */
+
+ /* follow current chain */
+ matchIndex -= DELTANEXTU16(chainTable, matchIndex + matchChainPos);
+
+ } /* while ((matchIndex>=lowestMatchIndex) && (nbAttempts)) */
+
+ if ( dict == usingDictCtxHc
+ && nbAttempts > 0
+ && ipIndex - lowestMatchIndex < LZ4_DISTANCE_MAX) {
+ size_t const dictEndOffset = (size_t)(dictCtx->end - dictCtx->prefixStart) + dictCtx->dictLimit;
+ U32 dictMatchIndex = dictCtx->hashTable[LZ4HC_hashPtr(ip)];
+ assert(dictEndOffset <= 1 GB);
+ matchIndex = dictMatchIndex + lowestMatchIndex - (U32)dictEndOffset;
+ while (ipIndex - matchIndex <= LZ4_DISTANCE_MAX && nbAttempts--) {
+ const BYTE* const matchPtr = dictCtx->prefixStart - dictCtx->dictLimit + dictMatchIndex;
+
+ if (LZ4_read32(matchPtr) == pattern) {
+ int mlt;
+ int back = 0;
+ const BYTE* vLimit = ip + (dictEndOffset - dictMatchIndex);
+ if (vLimit > iHighLimit) vLimit = iHighLimit;
+ mlt = (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH;
+ back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictCtx->prefixStart) : 0;
+ mlt -= back;
+ if (mlt > longest) {
+ longest = mlt;
+ *matchpos = prefixPtr - prefixIdx + matchIndex + back;
+ *startpos = ip + back;
+ } }
+
+ { U32 const nextOffset = DELTANEXTU16(dictCtx->chainTable, dictMatchIndex);
+ dictMatchIndex -= nextOffset;
+ matchIndex -= nextOffset;
+ } } }
+
+ 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 dictCtx_directive dict)
+{
+ 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, 0 /*chainSwap*/, dict, favorCompressionRatio);
+}
+
+/* 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)
+{
+#define ip (*_ip)
+#define op (*_op)
+#define anchor (*_anchor)
+
+ size_t length;
+ BYTE* const token = op++;
+
+#if defined(LZ4_DEBUG) && (LZ4_DEBUG >= 6)
+ static const BYTE* start = NULL;
+ static U32 totalCost = 0;
+ U32 const pos = (start==NULL) ? 0 : (U32)(anchor - start);
+ U32 const ll = (U32)(ip - anchor);
+ U32 const 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(6, "pos:%7u -- literals:%4u, match:%4i, offset:%5u, cost:%4u + %5u",
+ pos,
+ (U32)(ip - anchor), matchLength, (U32)(ip-match),
+ cost, totalCost);
+ totalCost += cost;
+#endif
+
+ /* Encode Literal length */
+ length = (size_t)(ip - anchor);
+ LZ4_STATIC_ASSERT(notLimited == 0);
+ /* Check output limit */
+ if (limit && ((op + (length / 255) + length + (2 + 1 + LASTLITERALS)) > oend)) {
+ DEBUGLOG(6, "Not enough room to write %i literals (%i bytes remaining)",
+ (int)length, (int)(oend - op));
+ return 1;
+ }
+ if (length >= RUN_MASK) {
+ size_t len = length - RUN_MASK;
+ *token = (RUN_MASK << ML_BITS);
+ for(; len >= 255 ; len -= 255) *op++ = 255;
+ *op++ = (BYTE)len;
+ } else {
+ *token = (BYTE)(length << ML_BITS);
+ }
+
+ /* Copy Literals */
+ LZ4_wildCopy8(op, anchor, op + length);
+ op += length;
+
+ /* Encode Offset */
+ assert( (ip - match) <= LZ4_DISTANCE_MAX ); /* note : consider providing offset as a value, rather than as a pointer difference */
+ LZ4_writeLE16(op, (U16)(ip - match)); op += 2;
+
+ /* Encode MatchLength */
+ assert(matchLength >= MINMATCH);
+ length = (size_t)matchLength - MINMATCH;
+ if (limit && (op + (length / 255) + (1 + LASTLITERALS) > oend)) {
+ DEBUGLOG(6, "Not enough room to write match length");
+ return 1; /* Check output limit */
+ }
+ if (length >= ML_MASK) {
+ *token += ML_MASK;
+ length -= ML_MASK;
+ for(; length >= 510 ; length -= 510) { *op++ = 255; *op++ = 255; }
+ if (length >= 255) { length -= 255; *op++ = 255; }
+ *op++ = (BYTE)length;
+ } else {
+ *token += (BYTE)(length);
+ }
+
+ /* Prepare next loop */
+ ip += matchLength;
+ anchor = ip;
+
+ return 0;
+}
+#undef ip
+#undef op
+#undef anchor
+
+LZ4_FORCE_INLINE int LZ4HC_compress_hashChain (
+ LZ4HC_CCtx_internal* const ctx,
+ const char* const source,
+ char* const dest,
+ int* srcSizePtr,
+ int const maxOutputSize,
+ int maxNbAttempts,
+ const limitedOutput_directive limit,
+ const dictCtx_directive dict
+ )
+{
+ const int inputSize = *srcSizePtr;
+ const int patternAnalysis = (maxNbAttempts > 128); /* levels 9+ */
+
+ 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 ml0, ml, ml2, ml3;
+ const BYTE* start0;
+ const BYTE* ref0;
+ const BYTE* ref = NULL;
+ const BYTE* start2 = NULL;
+ const BYTE* ref2 = NULL;
+ const BYTE* start3 = NULL;
+ const BYTE* ref3 = NULL;
+
+ /* init */
+ *srcSizePtr = 0;
+ if (limit == fillOutput) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */
+ if (inputSize < LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */
+
+ /* Main Loop */
+ while (ip <= mflimit) {
+ ml = LZ4HC_InsertAndFindBestMatch(ctx, ip, matchlimit, &ref, maxNbAttempts, patternAnalysis, dict);
+ 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, 0, dict, favorCompressionRatio);
+ } else {
+ ml2 = ml;
+ }
+
+ if (ml2 == ml) { /* No better match => encode ML1 */
+ optr = op;
+ if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow;
+ continue;
+ }
+
+ if (start0 < ip) { /* first match was skipped at least once */
+ if (start2 < ip + ml0) { /* squeezing ML1 between ML0(original ML1) and ML2 */
+ ip = start0; ref = ref0; ml = ml0; /* restore initial ML1 */
+ } }
+
+ /* 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, 0, dict, favorCompressionRatio);
+ } else {
+ ml3 = ml2;
+ }
+
+ if (ml3 == ml2) { /* No better match => encode ML1 and ML2 */
+ /* ip & ref are known; Now for ml */
+ if (start2 < ip+ml) ml = (int)(start2 - ip);
+ /* Now, encode 2 sequences */
+ optr = op;
+ if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow;
+ ip = start2;
+ optr = op;
+ if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml2, ref2, limit, oend)) {
+ ml = ml2;
+ ref = ref2;
+ 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(UPDATABLE(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 the first one ML1.
+ * ip & ref are known; Now decide ml.
+ */
+ if (start2 < ip+ml) {
+ if ((start2 - ip) < OPTIMAL_ML) {
+ 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(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow;
+
+ /* ML2 becomes ML1 */
+ ip = start2; ref = ref2; ml = ml2;
+
+ /* ML3 becomes ML2 */
+ start2 = start3; ref2 = ref3; ml2 = ml3;
+
+ /* let's find a new ML3 */
+ goto _Search3;
+ }
+
+_last_literals:
+ /* Encode Last Literals */
+ { size_t lastRunSize = (size_t)(iend - anchor); /* literals */
+ size_t llAdd = (lastRunSize + 255 - RUN_MASK) / 255;
+ size_t const totalSize = 1 + llAdd + lastRunSize;
+ if (limit == fillOutput) oend += LASTLITERALS; /* restore correct value */
+ if (limit && (op + totalSize > oend)) {
+ if (limit == limitedOutput) return 0;
+ /* adapt lastRunSize to fill 'dest' */
+ lastRunSize = (size_t)(oend - op) - 1 /*token*/;
+ llAdd = (lastRunSize + 256 - RUN_MASK) / 256;
+ lastRunSize -= llAdd;
+ }
+ DEBUGLOG(6, "Final literal run : %i literals", (int)lastRunSize);
+ ip = anchor + lastRunSize; /* can be != iend if limit==fillOutput */
+
+ if (lastRunSize >= RUN_MASK) {
+ size_t accumulator = lastRunSize - RUN_MASK;
+ *op++ = (RUN_MASK << ML_BITS);
+ for(; accumulator >= 255 ; accumulator -= 255) *op++ = 255;
+ *op++ = (BYTE) accumulator;
+ } else {
+ *op++ = (BYTE)(lastRunSize << ML_BITS);
+ }
+ LZ4_memcpy(op, anchor, lastRunSize);
+ op += lastRunSize;
+ }
+
+ /* End */
+ *srcSizePtr = (int) (((const char*)ip) - source);
+ return (int) (((char*)op)-dest);
+
+_dest_overflow:
+ if (limit == fillOutput) {
+ /* Assumption : ip, anchor, ml and ref must be set correctly */
+ size_t const ll = (size_t)(ip - anchor);
+ size_t const ll_addbytes = (ll + 240) / 255;
+ size_t const ll_totalCost = 1 + ll_addbytes + ll;
+ BYTE* const maxLitPos = oend - 3; /* 2 for offset, 1 for token */
+ DEBUGLOG(6, "Last sequence overflowing");
+ op = optr; /* restore correct out pointer */
+ if (op + ll_totalCost <= maxLitPos) {
+ /* ll validated; now adjust match length */
+ size_t const bytesLeftForMl = (size_t)(maxLitPos - (op+ll_totalCost));
+ size_t const maxMlSize = MINMATCH + (ML_MASK-1) + (bytesLeftForMl * 255);
+ assert(maxMlSize < INT_MAX); assert(ml >= 0);
+ if ((size_t)ml > maxMlSize) ml = (int)maxMlSize;
+ if ((oend + LASTLITERALS) - (op + ll_totalCost + 2) - 1 + ml >= MFLIMIT) {
+ LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, notLimited, oend);
+ } }
+ goto _last_literals;
+ }
+ /* compression failed */
+ return 0;
+}
+
+
+static int LZ4HC_compress_optimal( LZ4HC_CCtx_internal* ctx,
+ const char* const source, char* dst,
+ int* srcSizePtr, int dstCapacity,
+ int const nbSearches, size_t sufficient_len,
+ const limitedOutput_directive limit, int const fullUpdate,
+ const dictCtx_directive dict,
+ const HCfavor_e favorDecSpeed);
+
+
+LZ4_FORCE_INLINE int LZ4HC_compress_generic_internal (
+ LZ4HC_CCtx_internal* const ctx,
+ const char* const src,
+ char* const dst,
+ int* const srcSizePtr,
+ int const dstCapacity,
+ int cLevel,
+ const limitedOutput_directive limit,
+ const dictCtx_directive dict
+ )
+{
+ typedef enum { lz4hc, lz4opt } lz4hc_strat_e;
+ typedef struct {
+ lz4hc_strat_e strat;
+ int 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,16384,LZ4_OPT_NUM }, /* 12==LZ4HC_CLEVEL_MAX */
+ };
+
+ DEBUGLOG(4, "LZ4HC_compress_generic(ctx=%p, src=%p, srcSize=%d, limit=%d)",
+ ctx, src, *srcSizePtr, limit);
+
+ if (limit == fillOutput && dstCapacity < 1) return 0; /* Impossible to store anything */
+ if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size (too large or negative) */
+
+ ctx->end += *srcSizePtr;
+ if (cLevel < 1) cLevel = LZ4HC_CLEVEL_DEFAULT; /* note : convention is different from lz4frame, maybe something to review */
+ cLevel = MIN(LZ4HC_CLEVEL_MAX, cLevel);
+ { cParams_t const cParam = clTable[cLevel];
+ HCfavor_e const favor = ctx->favorDecSpeed ? favorDecompressionSpeed : favorCompressionRatio;
+ int result;
+
+ if (cParam.strat == lz4hc) {
+ result = LZ4HC_compress_hashChain(ctx,
+ src, dst, srcSizePtr, dstCapacity,
+ cParam.nbSearches, limit, dict);
+ } else {
+ assert(cParam.strat == lz4opt);
+ result = LZ4HC_compress_optimal(ctx,
+ src, dst, srcSizePtr, dstCapacity,
+ cParam.nbSearches, cParam.targetLength, limit,
+ cLevel == LZ4HC_CLEVEL_MAX, /* ultra mode */
+ dict, favor);
+ }
+ if (result <= 0) ctx->dirty = 1;
+ return result;
+ }
+}
+
+static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* ctxPtr, const BYTE* newBlock);
+
+static int
+LZ4HC_compress_generic_noDictCtx (
+ LZ4HC_CCtx_internal* const ctx,
+ const char* const src,
+ char* const dst,
+ int* const srcSizePtr,
+ int const dstCapacity,
+ int cLevel,
+ limitedOutput_directive limit
+ )
+{
+ assert(ctx->dictCtx == NULL);
+ return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, noDictCtx);
+}
+
+static int
+LZ4HC_compress_generic_dictCtx (
+ LZ4HC_CCtx_internal* const ctx,
+ const char* const src,
+ char* const dst,
+ int* const srcSizePtr,
+ int const dstCapacity,
+ int cLevel,
+ limitedOutput_directive limit
+ )
+{
+ const size_t position = (size_t)(ctx->end - ctx->prefixStart) + (ctx->dictLimit - ctx->lowLimit);
+ assert(ctx->dictCtx != NULL);
+ if (position >= 64 KB) {
+ ctx->dictCtx = NULL;
+ return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
+ } else if (position == 0 && *srcSizePtr > 4 KB) {
+ LZ4_memcpy(ctx, ctx->dictCtx, sizeof(LZ4HC_CCtx_internal));
+ LZ4HC_setExternalDict(ctx, (const BYTE *)src);
+ ctx->compressionLevel = (short)cLevel;
+ return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
+ } else {
+ return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, usingDictCtxHc);
+ }
+}
+
+static int
+LZ4HC_compress_generic (
+ LZ4HC_CCtx_internal* const ctx,
+ const char* const src,
+ char* const dst,
+ int* const srcSizePtr,
+ int const dstCapacity,
+ int cLevel,
+ limitedOutput_directive limit
+ )
+{
+ if (ctx->dictCtx == NULL) {
+ return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
+ } else {
+ return LZ4HC_compress_generic_dictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
+ }
+}
+
+
+int LZ4_sizeofStateHC(void) { return (int)sizeof(LZ4_streamHC_t); }
+
+static size_t LZ4_streamHC_t_alignment(void)
+{
+#if LZ4_ALIGN_TEST
+ typedef struct { char c; LZ4_streamHC_t t; } t_a;
+ return sizeof(t_a) - sizeof(LZ4_streamHC_t);
+#else
+ return 1; /* effectively disabled */
+#endif
+}
+
+/* state is presumed correctly initialized,
+ * in which case its size and alignment have already been validate */
+int LZ4_compress_HC_extStateHC_fastReset (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
+{
+ LZ4HC_CCtx_internal* const ctx = &((LZ4_streamHC_t*)state)->internal_donotuse;
+ if (!LZ4_isAligned(state, LZ4_streamHC_t_alignment())) return 0;
+ LZ4_resetStreamHC_fast((LZ4_streamHC_t*)state, compressionLevel);
+ LZ4HC_init_internal (ctx, (const BYTE*)src);
+ if (dstCapacity < LZ4_compressBound(srcSize))
+ return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, limitedOutput);
+ else
+ return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, notLimited);
+}
+
+int LZ4_compress_HC_extStateHC (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
+{
+ LZ4_streamHC_t* const ctx = LZ4_initStreamHC(state, sizeof(*ctx));
+ if (ctx==NULL) return 0; /* init failure */
+ return LZ4_compress_HC_extStateHC_fastReset(state, src, dst, srcSize, dstCapacity, compressionLevel);
+}
+
+int LZ4_compress_HC(const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
+{
+ int cSize;
+#if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1
+ LZ4_streamHC_t* const statePtr = (LZ4_streamHC_t*)ALLOC(sizeof(LZ4_streamHC_t));
+ if (statePtr==NULL) return 0;
+#else
+ LZ4_streamHC_t state;
+ LZ4_streamHC_t* const statePtr = &state;
+#endif
+ cSize = LZ4_compress_HC_extStateHC(statePtr, src, dst, srcSize, dstCapacity, compressionLevel);
+#if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1
+ FREEMEM(statePtr);
+#endif
+ return cSize;
+}
+
+/* state is presumed sized correctly (>= sizeof(LZ4_streamHC_t)) */
+int LZ4_compress_HC_destSize(void* state, const char* source, char* dest, int* sourceSizePtr, int targetDestSize, int cLevel)
+{
+ LZ4_streamHC_t* const ctx = LZ4_initStreamHC(state, sizeof(*ctx));
+ if (ctx==NULL) return 0; /* init failure */
+ LZ4HC_init_internal(&ctx->internal_donotuse, (const BYTE*) source);
+ LZ4_setCompressionLevel(ctx, cLevel);
+ return LZ4HC_compress_generic(&ctx->internal_donotuse, source, dest, sourceSizePtr, targetDestSize, cLevel, fillOutput);
+}
+
+
+
+/**************************************
+* Streaming Functions
+**************************************/
+/* allocation */
+#if !defined(LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION)
+LZ4_streamHC_t* LZ4_createStreamHC(void)
+{
+ LZ4_streamHC_t* const state =
+ (LZ4_streamHC_t*)ALLOC_AND_ZERO(sizeof(LZ4_streamHC_t));
+ if (state == NULL) return NULL;
+ LZ4_setCompressionLevel(state, LZ4HC_CLEVEL_DEFAULT);
+ return state;
+}
+
+int LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr)
+{
+ DEBUGLOG(4, "LZ4_freeStreamHC(%p)", LZ4_streamHCPtr);
+ if (!LZ4_streamHCPtr) return 0; /* support free on NULL */
+ FREEMEM(LZ4_streamHCPtr);
+ return 0;
+}
+#endif
+
+
+LZ4_streamHC_t* LZ4_initStreamHC (void* buffer, size_t size)
+{
+ LZ4_streamHC_t* const LZ4_streamHCPtr = (LZ4_streamHC_t*)buffer;
+ DEBUGLOG(4, "LZ4_initStreamHC(%p, %u)", buffer, (unsigned)size);
+ /* check conditions */
+ if (buffer == NULL) return NULL;
+ if (size < sizeof(LZ4_streamHC_t)) return NULL;
+ if (!LZ4_isAligned(buffer, LZ4_streamHC_t_alignment())) return NULL;
+ /* init */
+ { LZ4HC_CCtx_internal* const hcstate = &(LZ4_streamHCPtr->internal_donotuse);
+ MEM_INIT(hcstate, 0, sizeof(*hcstate)); }
+ LZ4_setCompressionLevel(LZ4_streamHCPtr, LZ4HC_CLEVEL_DEFAULT);
+ return LZ4_streamHCPtr;
+}
+
+/* just a stub */
+void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
+{
+ LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr));
+ LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel);
+}
+
+void LZ4_resetStreamHC_fast (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
+{
+ DEBUGLOG(4, "LZ4_resetStreamHC_fast(%p, %d)", LZ4_streamHCPtr, compressionLevel);
+ if (LZ4_streamHCPtr->internal_donotuse.dirty) {
+ LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr));
+ } else {
+ /* preserve end - prefixStart : can trigger clearTable's threshold */
+ if (LZ4_streamHCPtr->internal_donotuse.end != NULL) {
+ LZ4_streamHCPtr->internal_donotuse.end -= (uptrval)LZ4_streamHCPtr->internal_donotuse.prefixStart;
+ } else {
+ assert(LZ4_streamHCPtr->internal_donotuse.prefixStart == NULL);
+ }
+ LZ4_streamHCPtr->internal_donotuse.prefixStart = NULL;
+ LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL;
+ }
+ LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel);
+}
+
+void LZ4_setCompressionLevel(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
+{
+ DEBUGLOG(5, "LZ4_setCompressionLevel(%p, %d)", LZ4_streamHCPtr, compressionLevel);
+ if (compressionLevel < 1) compressionLevel = LZ4HC_CLEVEL_DEFAULT;
+ if (compressionLevel > LZ4HC_CLEVEL_MAX) compressionLevel = LZ4HC_CLEVEL_MAX;
+ LZ4_streamHCPtr->internal_donotuse.compressionLevel = (short)compressionLevel;
+}
+
+void LZ4_favorDecompressionSpeed(LZ4_streamHC_t* LZ4_streamHCPtr, int favor)
+{
+ LZ4_streamHCPtr->internal_donotuse.favorDecSpeed = (favor!=0);
+}
+
+/* LZ4_loadDictHC() :
+ * LZ4_streamHCPtr is presumed properly initialized */
+int LZ4_loadDictHC (LZ4_streamHC_t* LZ4_streamHCPtr,
+ const char* dictionary, int dictSize)
+{
+ LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
+ DEBUGLOG(4, "LZ4_loadDictHC(ctx:%p, dict:%p, dictSize:%d)", LZ4_streamHCPtr, dictionary, dictSize);
+ assert(LZ4_streamHCPtr != NULL);
+ if (dictSize > 64 KB) {
+ dictionary += (size_t)dictSize - 64 KB;
+ dictSize = 64 KB;
+ }
+ /* need a full initialization, there are bad side-effects when using resetFast() */
+ { int const cLevel = ctxPtr->compressionLevel;
+ LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr));
+ LZ4_setCompressionLevel(LZ4_streamHCPtr, cLevel);
+ }
+ LZ4HC_init_internal (ctxPtr, (const BYTE*)dictionary);
+ ctxPtr->end = (const BYTE*)dictionary + dictSize;
+ if (dictSize >= 4) LZ4HC_Insert (ctxPtr, ctxPtr->end-3);
+ return dictSize;
+}
+
+void LZ4_attach_HC_dictionary(LZ4_streamHC_t *working_stream, const LZ4_streamHC_t *dictionary_stream) {
+ working_stream->internal_donotuse.dictCtx = dictionary_stream != NULL ? &(dictionary_stream->internal_donotuse) : NULL;
+}
+
+/* compression */
+
+static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* ctxPtr, const BYTE* newBlock)
+{
+ DEBUGLOG(4, "LZ4HC_setExternalDict(%p, %p)", ctxPtr, newBlock);
+ if (ctxPtr->end >= ctxPtr->prefixStart + 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->dictStart = ctxPtr->prefixStart;
+ ctxPtr->dictLimit += (U32)(ctxPtr->end - ctxPtr->prefixStart);
+ ctxPtr->prefixStart = newBlock;
+ ctxPtr->end = newBlock;
+ ctxPtr->nextToUpdate = ctxPtr->dictLimit; /* match referencing will resume from there */
+
+ /* cannot reference an extDict and a dictCtx at the same time */
+ ctxPtr->dictCtx = NULL;
+}
+
+static int
+LZ4_compressHC_continue_generic (LZ4_streamHC_t* LZ4_streamHCPtr,
+ const char* src, char* dst,
+ int* srcSizePtr, int dstCapacity,
+ limitedOutput_directive limit)
+{
+ LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
+ DEBUGLOG(5, "LZ4_compressHC_continue_generic(ctx=%p, src=%p, srcSize=%d, limit=%d)",
+ LZ4_streamHCPtr, src, *srcSizePtr, limit);
+ assert(ctxPtr != NULL);
+ /* auto-init if forgotten */
+ if (ctxPtr->prefixStart == NULL) LZ4HC_init_internal (ctxPtr, (const BYTE*) src);
+
+ /* Check overflow */
+ if ((size_t)(ctxPtr->end - ctxPtr->prefixStart) + ctxPtr->dictLimit > 2 GB) {
+ size_t dictSize = (size_t)(ctxPtr->end - ctxPtr->prefixStart);
+ 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->dictStart;
+ const BYTE* const dictEnd = ctxPtr->dictStart + (ctxPtr->dictLimit - ctxPtr->lowLimit);
+ if ((sourceEnd > dictBegin) && ((const BYTE*)src < dictEnd)) {
+ if (sourceEnd > dictEnd) sourceEnd = dictEnd;
+ ctxPtr->lowLimit += (U32)(sourceEnd - ctxPtr->dictStart);
+ ctxPtr->dictStart += (U32)(sourceEnd - ctxPtr->dictStart);
+ if (ctxPtr->dictLimit - ctxPtr->lowLimit < 4) {
+ ctxPtr->lowLimit = ctxPtr->dictLimit;
+ ctxPtr->dictStart = ctxPtr->prefixStart;
+ } } }
+
+ 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, notLimited);
+}
+
+int LZ4_compress_HC_continue_destSize (LZ4_streamHC_t* LZ4_streamHCPtr, const char* src, char* dst, int* srcSizePtr, int targetDestSize)
+{
+ return LZ4_compressHC_continue_generic(LZ4_streamHCPtr, src, dst, srcSizePtr, targetDestSize, fillOutput);
+}
+
+
+
+/* LZ4_saveDictHC :
+ * save history content
+ * into a user-provided buffer
+ * which is then used to continue compression
+ */
+int LZ4_saveDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, char* safeBuffer, int dictSize)
+{
+ LZ4HC_CCtx_internal* const streamPtr = &LZ4_streamHCPtr->internal_donotuse;
+ int const prefixSize = (int)(streamPtr->end - streamPtr->prefixStart);
+ DEBUGLOG(5, "LZ4_saveDictHC(%p, %p, %d)", LZ4_streamHCPtr, safeBuffer, dictSize);
+ assert(prefixSize >= 0);
+ if (dictSize > 64 KB) dictSize = 64 KB;
+ if (dictSize < 4) dictSize = 0;
+ if (dictSize > prefixSize) dictSize = prefixSize;
+ if (safeBuffer == NULL) assert(dictSize == 0);
+ if (dictSize > 0)
+ LZ4_memmove(safeBuffer, streamPtr->end - dictSize, dictSize);
+ { U32 const endIndex = (U32)(streamPtr->end - streamPtr->prefixStart) + streamPtr->dictLimit;
+ streamPtr->end = (const BYTE*)safeBuffer + dictSize;
+ streamPtr->prefixStart = streamPtr->end - dictSize;
+ streamPtr->dictLimit = endIndex - (U32)dictSize;
+ streamPtr->lowLimit = endIndex - (U32)dictSize;
+ streamPtr->dictStart = streamPtr->prefixStart;
+ if (streamPtr->nextToUpdate < streamPtr->dictLimit)
+ streamPtr->nextToUpdate = streamPtr->dictLimit;
+ }
+ return dictSize;
+}
+
+
+/***************************************************
+* Deprecated Functions
+***************************************************/
+
+/* These functions currently generate deprecation warnings */
+
+/* Wrappers for deprecated compression functions */
+int LZ4_compressHC(const char* src, char* dst, int srcSize) { return LZ4_compress_HC (src, dst, srcSize, LZ4_compressBound(srcSize), 0); }
+int LZ4_compressHC_limitedOutput(const char* src, char* dst, int srcSize, int maxDstSize) { return LZ4_compress_HC(src, dst, srcSize, maxDstSize, 0); }
+int LZ4_compressHC2(const char* src, char* dst, int srcSize, int cLevel) { return LZ4_compress_HC (src, dst, srcSize, LZ4_compressBound(srcSize), cLevel); }
+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 sizeof(LZ4_streamHC_t); }
+
+/* state is presumed correctly sized, aka >= sizeof(LZ4_streamHC_t)
+ * @return : 0 on success, !=0 if error */
+int LZ4_resetStreamStateHC(void* state, char* inputBuffer)
+{
+ LZ4_streamHC_t* const hc4 = LZ4_initStreamHC(state, sizeof(*hc4));
+ if (hc4 == NULL) return 1; /* init failed */
+ LZ4HC_init_internal (&hc4->internal_donotuse, (const BYTE*)inputBuffer);
+ return 0;
+}
+
+#if !defined(LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION)
+void* LZ4_createHC (const char* inputBuffer)
+{
+ LZ4_streamHC_t* const hc4 = LZ4_createStreamHC();
+ if (hc4 == NULL) return NULL; /* not enough memory */
+ LZ4HC_init_internal (&hc4->internal_donotuse, (const BYTE*)inputBuffer);
+ return hc4;
+}
+
+int LZ4_freeHC (void* LZ4HC_Data)
+{
+ if (!LZ4HC_Data) return 0; /* support free on NULL */
+ FREEMEM(LZ4HC_Data);
+ return 0;
+}
+#endif
+
+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, notLimited);
+}
+
+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)
+{
+ LZ4_streamHC_t* const ctx = (LZ4_streamHC_t*)LZ4HC_Data;
+ const BYTE* bufferStart = ctx->internal_donotuse.prefixStart - ctx->internal_donotuse.dictLimit + ctx->internal_donotuse.lowLimit;
+ LZ4_resetStreamHC_fast(ctx, ctx->internal_donotuse.compressionLevel);
+ /* avoid const char * -> char * conversion warning :( */
+ return (char*)(uptrval)bufferStart;
+}
+
+
+/* ================================================
+ * LZ4 Optimal parser (levels [LZ4HC_CLEVEL_OPT_MIN - LZ4HC_CLEVEL_MAX])
+ * ===============================================*/
+typedef struct {
+ int price;
+ int off;
+ int mlen;
+ int litlen;
+} LZ4HC_optimal_t;
+
+/* price in bytes */
+LZ4_FORCE_INLINE int LZ4HC_literalsPrice(int const litlen)
+{
+ int price = litlen;
+ assert(litlen >= 0);
+ if (litlen >= (int)RUN_MASK)
+ price += 1 + ((litlen-(int)RUN_MASK) / 255);
+ return price;
+}
+
+
+/* requires mlen >= MINMATCH */
+LZ4_FORCE_INLINE int LZ4HC_sequencePrice(int litlen, int mlen)
+{
+ int price = 1 + 2 ; /* token + 16-bit offset */
+ assert(litlen >= 0);
+ assert(mlen >= MINMATCH);
+
+ price += LZ4HC_literalsPrice(litlen);
+
+ if (mlen >= (int)(ML_MASK+MINMATCH))
+ price += 1 + ((mlen-(int)(ML_MASK+MINMATCH)) / 255);
+
+ return price;
+}
+
+
+typedef struct {
+ int off;
+ int len;
+} LZ4HC_match_t;
+
+LZ4_FORCE_INLINE LZ4HC_match_t
+LZ4HC_FindLongerMatch(LZ4HC_CCtx_internal* const ctx,
+ const BYTE* ip, const BYTE* const iHighLimit,
+ int minLen, int nbSearches,
+ const dictCtx_directive dict,
+ const HCfavor_e favorDecSpeed)
+{
+ LZ4HC_match_t match = { 0 , 0 };
+ const BYTE* matchPtr = NULL;
+ /* 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 */
+ int matchLength = LZ4HC_InsertAndGetWiderMatch(ctx, ip, ip, iHighLimit, minLen, &matchPtr, &ip, nbSearches, 1 /*patternAnalysis*/, 1 /*chainSwap*/, dict, favorDecSpeed);
+ if (matchLength <= minLen) return match;
+ if (favorDecSpeed) {
+ if ((matchLength>18) & (matchLength<=36)) matchLength=18; /* favor shortcut */
+ }
+ match.len = matchLength;
+ match.off = (int)(ip-matchPtr);
+ return match;
+}
+
+
+static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx,
+ const char* const source,
+ char* dst,
+ int* srcSizePtr,
+ int dstCapacity,
+ int const nbSearches,
+ size_t sufficient_len,
+ const limitedOutput_directive limit,
+ int const fullUpdate,
+ const dictCtx_directive dict,
+ const HCfavor_e favorDecSpeed)
+{
+ int retval = 0;
+#define TRAILING_LITERALS 3
+#if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1
+ LZ4HC_optimal_t* const opt = (LZ4HC_optimal_t*)ALLOC(sizeof(LZ4HC_optimal_t) * (LZ4_OPT_NUM + TRAILING_LITERALS));
+#else
+ LZ4HC_optimal_t opt[LZ4_OPT_NUM + TRAILING_LITERALS]; /* ~64 KB, which is a bit large for stack... */
+#endif
+
+ const BYTE* ip = (const BYTE*) source;
+ const BYTE* anchor = ip;
+ const BYTE* const iend = ip + *srcSizePtr;
+ const BYTE* const mflimit = iend - MFLIMIT;
+ const BYTE* const matchlimit = iend - LASTLITERALS;
+ BYTE* op = (BYTE*) dst;
+ BYTE* opSaved = (BYTE*) dst;
+ BYTE* oend = op + dstCapacity;
+ int ovml = MINMATCH; /* overflow - last sequence */
+ const BYTE* ovref = NULL;
+
+ /* init */
+#if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1
+ if (opt == NULL) goto _return_label;
+#endif
+ DEBUGLOG(5, "LZ4HC_compress_optimal(dst=%p, dstCapa=%u)", dst, (unsigned)dstCapacity);
+ *srcSizePtr = 0;
+ if (limit == fillOutput) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */
+ if (sufficient_len >= LZ4_OPT_NUM) sufficient_len = LZ4_OPT_NUM-1;
+
+ /* Main Loop */
+ while (ip <= mflimit) {
+ int const llen = (int)(ip - anchor);
+ int best_mlen, best_off;
+ int cur, last_match_pos = 0;
+
+ LZ4HC_match_t const firstMatch = LZ4HC_FindLongerMatch(ctx, ip, matchlimit, MINMATCH-1, nbSearches, dict, favorDecSpeed);
+ if (firstMatch.len==0) { ip++; continue; }
+
+ if ((size_t)firstMatch.len > sufficient_len) {
+ /* good enough solution : immediate encoding */
+ int const firstML = firstMatch.len;
+ const BYTE* const matchPos = ip - firstMatch.off;
+ opSaved = op;
+ if ( LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), firstML, matchPos, limit, oend) ) { /* updates ip, op and anchor */
+ ovml = firstML;
+ ovref = matchPos;
+ goto _dest_overflow;
+ }
+ continue;
+ }
+
+ /* set prices for first positions (literals) */
+ { int rPos;
+ for (rPos = 0 ; rPos < MINMATCH ; rPos++) {
+ int const cost = LZ4HC_literalsPrice(llen + rPos);
+ opt[rPos].mlen = 1;
+ opt[rPos].off = 0;
+ opt[rPos].litlen = llen + rPos;
+ opt[rPos].price = cost;
+ DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i) -- initial setup",
+ rPos, cost, opt[rPos].litlen);
+ } }
+ /* set prices using initial match */
+ { int mlen = MINMATCH;
+ int const matchML = firstMatch.len; /* necessarily < sufficient_len < LZ4_OPT_NUM */
+ int const offset = firstMatch.off;
+ assert(matchML < LZ4_OPT_NUM);
+ for ( ; mlen <= matchML ; mlen++) {
+ int const cost = LZ4HC_sequencePrice(llen, mlen);
+ opt[mlen].mlen = mlen;
+ opt[mlen].off = offset;
+ opt[mlen].litlen = llen;
+ opt[mlen].price = cost;
+ DEBUGLOG(7, "rPos:%3i => price:%3i (matchlen=%i) -- initial setup",
+ mlen, cost, mlen);
+ } }
+ last_match_pos = firstMatch.len;
+ { int addLit;
+ for (addLit = 1; addLit <= TRAILING_LITERALS; addLit ++) {
+ opt[last_match_pos+addLit].mlen = 1; /* literal */
+ opt[last_match_pos+addLit].off = 0;
+ opt[last_match_pos+addLit].litlen = addLit;
+ opt[last_match_pos+addLit].price = opt[last_match_pos].price + LZ4HC_literalsPrice(addLit);
+ DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i) -- initial setup",
+ last_match_pos+addLit, opt[last_match_pos+addLit].price, addLit);
+ } }
+
+ /* check further positions */
+ for (cur = 1; cur < last_match_pos; cur++) {
+ const BYTE* const curPtr = ip + cur;
+ LZ4HC_match_t newMatch;
+
+ if (curPtr > mflimit) break;
+ DEBUGLOG(7, "rPos:%u[%u] vs [%u]%u",
+ cur, opt[cur].price, opt[cur+1].price, cur+1);
+ if (fullUpdate) {
+ /* not useful to search here if next position has same (or lower) cost */
+ if ( (opt[cur+1].price <= opt[cur].price)
+ /* in some cases, next position has same cost, but cost rises sharply after, so a small match would still be beneficial */
+ && (opt[cur+MINMATCH].price < opt[cur].price + 3/*min seq price*/) )
+ continue;
+ } else {
+ /* not useful to search here if next position has same (or lower) cost */
+ if (opt[cur+1].price <= opt[cur].price) continue;
+ }
+
+ DEBUGLOG(7, "search at rPos:%u", cur);
+ if (fullUpdate)
+ newMatch = LZ4HC_FindLongerMatch(ctx, curPtr, matchlimit, MINMATCH-1, nbSearches, dict, favorDecSpeed);
+ else
+ /* only test matches of minimum length; slightly faster, but misses a few bytes */
+ newMatch = LZ4HC_FindLongerMatch(ctx, curPtr, matchlimit, last_match_pos - cur, nbSearches, dict, favorDecSpeed);
+ if (!newMatch.len) continue;
+
+ if ( ((size_t)newMatch.len > sufficient_len)
+ || (newMatch.len + cur >= LZ4_OPT_NUM) ) {
+ /* immediate encoding */
+ best_mlen = newMatch.len;
+ best_off = newMatch.off;
+ last_match_pos = cur + 1;
+ goto encode;
+ }
+
+ /* before match : set price with literals at beginning */
+ { int const baseLitlen = opt[cur].litlen;
+ int litlen;
+ for (litlen = 1; litlen < MINMATCH; litlen++) {
+ int const price = opt[cur].price - LZ4HC_literalsPrice(baseLitlen) + LZ4HC_literalsPrice(baseLitlen+litlen);
+ int const pos = cur + litlen;
+ if (price < opt[pos].price) {
+ opt[pos].mlen = 1; /* literal */
+ opt[pos].off = 0;
+ opt[pos].litlen = baseLitlen+litlen;
+ opt[pos].price = price;
+ DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i)",
+ pos, price, opt[pos].litlen);
+ } } }
+
+ /* set prices using match at position = cur */
+ { int const matchML = newMatch.len;
+ int ml = MINMATCH;
+
+ assert(cur + newMatch.len < LZ4_OPT_NUM);
+ for ( ; ml <= matchML ; ml++) {
+ int const pos = cur + ml;
+ int const offset = newMatch.off;
+ int price;
+ int ll;
+ DEBUGLOG(7, "testing price rPos %i (last_match_pos=%i)",
+ pos, last_match_pos);
+ if (opt[cur].mlen == 1) {
+ ll = opt[cur].litlen;
+ price = ((cur > ll) ? opt[cur - ll].price : 0)
+ + LZ4HC_sequencePrice(ll, ml);
+ } else {
+ ll = 0;
+ price = opt[cur].price + LZ4HC_sequencePrice(0, ml);
+ }
+
+ assert((U32)favorDecSpeed <= 1);
+ if (pos > last_match_pos+TRAILING_LITERALS
+ || price <= opt[pos].price - (int)favorDecSpeed) {
+ DEBUGLOG(7, "rPos:%3i => price:%3i (matchlen=%i)",
+ pos, price, ml);
+ assert(pos < LZ4_OPT_NUM);
+ if ( (ml == matchML) /* last pos of last match */
+ && (last_match_pos < pos) )
+ last_match_pos = pos;
+ opt[pos].mlen = ml;
+ opt[pos].off = offset;
+ opt[pos].litlen = ll;
+ opt[pos].price = price;
+ } } }
+ /* complete following positions with literals */
+ { int addLit;
+ for (addLit = 1; addLit <= TRAILING_LITERALS; addLit ++) {
+ opt[last_match_pos+addLit].mlen = 1; /* literal */
+ opt[last_match_pos+addLit].off = 0;
+ opt[last_match_pos+addLit].litlen = addLit;
+ opt[last_match_pos+addLit].price = opt[last_match_pos].price + LZ4HC_literalsPrice(addLit);
+ DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i)", last_match_pos+addLit, opt[last_match_pos+addLit].price, addLit);
+ } }
+ } /* for (cur = 1; cur <= last_match_pos; cur++) */
+
+ assert(last_match_pos < LZ4_OPT_NUM + TRAILING_LITERALS);
+ best_mlen = opt[last_match_pos].mlen;
+ best_off = opt[last_match_pos].off;
+ cur = last_match_pos - best_mlen;
+
+encode: /* cur, last_match_pos, best_mlen, best_off must be set */
+ assert(cur < LZ4_OPT_NUM);
+ assert(last_match_pos >= 1); /* == 1 when only one candidate */
+ DEBUGLOG(6, "reverse traversal, looking for shortest path (last_match_pos=%i)", last_match_pos);
+ { int candidate_pos = cur;
+ int selected_matchLength = best_mlen;
+ int selected_offset = best_off;
+ while (1) { /* from end to beginning */
+ int const next_matchLength = opt[candidate_pos].mlen; /* can be 1, means literal */
+ int const next_offset = opt[candidate_pos].off;
+ DEBUGLOG(7, "pos %i: sequence length %i", candidate_pos, selected_matchLength);
+ opt[candidate_pos].mlen = selected_matchLength;
+ opt[candidate_pos].off = selected_offset;
+ selected_matchLength = next_matchLength;
+ selected_offset = next_offset;
+ if (next_matchLength > candidate_pos) break; /* last match elected, first match to encode */
+ assert(next_matchLength > 0); /* can be 1, means literal */
+ candidate_pos -= next_matchLength;
+ } }
+
+ /* encode all recorded sequences in order */
+ { int rPos = 0; /* relative position (to ip) */
+ while (rPos < last_match_pos) {
+ int const ml = opt[rPos].mlen;
+ int const offset = opt[rPos].off;
+ if (ml == 1) { ip++; rPos++; continue; } /* literal; note: can end up with several literals, in which case, skip them */
+ rPos += ml;
+ assert(ml >= MINMATCH);
+ assert((offset >= 1) && (offset <= LZ4_DISTANCE_MAX));
+ opSaved = op;
+ if ( LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ip - offset, limit, oend) ) { /* updates ip, op and anchor */
+ ovml = ml;
+ ovref = ip - offset;
+ goto _dest_overflow;
+ } } }
+ } /* while (ip <= mflimit) */
+
+_last_literals:
+ /* Encode Last Literals */
+ { size_t lastRunSize = (size_t)(iend - anchor); /* literals */
+ size_t llAdd = (lastRunSize + 255 - RUN_MASK) / 255;
+ size_t const totalSize = 1 + llAdd + lastRunSize;
+ if (limit == fillOutput) oend += LASTLITERALS; /* restore correct value */
+ if (limit && (op + totalSize > oend)) {
+ if (limit == limitedOutput) { /* Check output limit */
+ retval = 0;
+ goto _return_label;
+ }
+ /* adapt lastRunSize to fill 'dst' */
+ lastRunSize = (size_t)(oend - op) - 1 /*token*/;
+ llAdd = (lastRunSize + 256 - RUN_MASK) / 256;
+ lastRunSize -= llAdd;
+ }
+ DEBUGLOG(6, "Final literal run : %i literals", (int)lastRunSize);
+ ip = anchor + lastRunSize; /* can be != iend if limit==fillOutput */
+
+ if (lastRunSize >= RUN_MASK) {
+ size_t accumulator = lastRunSize - RUN_MASK;
+ *op++ = (RUN_MASK << ML_BITS);
+ for(; accumulator >= 255 ; accumulator -= 255) *op++ = 255;
+ *op++ = (BYTE) accumulator;
+ } else {
+ *op++ = (BYTE)(lastRunSize << ML_BITS);
+ }
+ LZ4_memcpy(op, anchor, lastRunSize);
+ op += lastRunSize;
+ }
+
+ /* End */
+ *srcSizePtr = (int) (((const char*)ip) - source);
+ retval = (int) ((char*)op-dst);
+ goto _return_label;
+
+_dest_overflow:
+if (limit == fillOutput) {
+ /* Assumption : ip, anchor, ovml and ovref must be set correctly */
+ size_t const ll = (size_t)(ip - anchor);
+ size_t const ll_addbytes = (ll + 240) / 255;
+ size_t const ll_totalCost = 1 + ll_addbytes + ll;
+ BYTE* const maxLitPos = oend - 3; /* 2 for offset, 1 for token */
+ DEBUGLOG(6, "Last sequence overflowing (only %i bytes remaining)", (int)(oend-1-opSaved));
+ op = opSaved; /* restore correct out pointer */
+ if (op + ll_totalCost <= maxLitPos) {
+ /* ll validated; now adjust match length */
+ size_t const bytesLeftForMl = (size_t)(maxLitPos - (op+ll_totalCost));
+ size_t const maxMlSize = MINMATCH + (ML_MASK-1) + (bytesLeftForMl * 255);
+ assert(maxMlSize < INT_MAX); assert(ovml >= 0);
+ if ((size_t)ovml > maxMlSize) ovml = (int)maxMlSize;
+ if ((oend + LASTLITERALS) - (op + ll_totalCost + 2) - 1 + ovml >= MFLIMIT) {
+ DEBUGLOG(6, "Space to end : %i + ml (%i)", (int)((oend + LASTLITERALS) - (op + ll_totalCost + 2) - 1), ovml);
+ DEBUGLOG(6, "Before : ip = %p, anchor = %p", ip, anchor);
+ LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ovml, ovref, notLimited, oend);
+ DEBUGLOG(6, "After : ip = %p, anchor = %p", ip, anchor);
+ } }
+ goto _last_literals;
+}
+_return_label:
+#if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1
+ FREEMEM(opt);
+#endif
+ return retval;
+}