From 8dfb9d61593cfde85974bbe8838168481063d9e6 Mon Sep 17 00:00:00 2001 From: "yann.collet.73@gmail.com" Date: Sun, 13 May 2012 17:59:10 +0000 Subject: Added : LZ4 HC : Now integrated into main trunk. LZ4_HC license moved to BSD git-svn-id: https://lz4.googlecode.com/svn/trunk@66 650e7d94-2a16-8b24-b05c-7c0b3f6821cd --- Makefile | 8 +- bench.c | 7 + lz4.c | 4 + lz4.h | 8 +- lz4demo.c | 38 ++-- lz4hc.c | 663 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ lz4hc.h | 60 ++++++ 7 files changed, 768 insertions(+), 20 deletions(-) create mode 100644 lz4hc.c create mode 100644 lz4hc.h diff --git a/Makefile b/Makefile index 62fe2a6..8a2696a 100644 --- a/Makefile +++ b/Makefile @@ -10,11 +10,11 @@ endif all: lz4demo64 lz4demo32 -lz4demo64: lz4.c lz4.h bench.c lz4demo.c - gcc -O3 -I. -std=c99 -Wall -W -Wundef -Wno-implicit-function-declaration lz4.c bench.c lz4demo.c -o $(OUTPUT64) +lz4demo64: lz4.c lz4.h lz4hc.c lz4hc.h bench.c lz4demo.c + gcc -O3 -I. -std=c99 -Wall -W -Wundef -Wno-implicit-function-declaration lz4hc.c lz4.c bench.c lz4demo.c -o $(OUTPUT64) -lz4demo32: lz4.c lz4.h bench.c lz4demo.c - gcc -m32 -Os -march=native -I. -std=c99 -Wall -W -Wundef -Wno-implicit-function-declaration lz4.c bench.c lz4demo.c -o $(OUTPUT32) +lz4demo32: lz4.c lz4.h lz4hc.c lz4hc.h bench.c lz4demo.c + gcc -m32 -Os -march=native -I. -std=c99 -Wall -W -Wundef -Wno-implicit-function-declaration lz4hc.c lz4.c bench.c lz4demo.c -o $(OUTPUT32) clean: rm -f core *.o $(OUTPUT32) $(OUTPUT64) diff --git a/bench.c b/bench.c index 1b5dd6c..b56dcb7 100644 --- a/bench.c +++ b/bench.c @@ -1,6 +1,7 @@ /* bench.c - Demo program to benchmark open-source compression algorithm Copyright (C) Yann Collet 2012 + GPL v2 License This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -51,6 +52,9 @@ #include // stat64 #include "lz4.h" +#define COMPRESSOR0 LZ4_compress +#include "lz4hc.h" +#define COMPRESSOR1 LZ4_compressHC #define DEFAULTCOMPRESSOR LZ4_compress @@ -272,6 +276,9 @@ int BMK_benchFile(char** fileNamesTable, int nbFiles, int cLevel) #ifdef COMPRESSOR0 case 0 : compP.compressionFunction = COMPRESSOR0; break; #endif +#ifdef COMPRESSOR1 + case 1 : compP.compressionFunction = COMPRESSOR1; break; +#endif default : compP.compressionFunction = DEFAULTCOMPRESSOR; } compP.decompressionFunction = LZ4_uncompress; diff --git a/lz4.c b/lz4.c index 8226361..06e2829 100644 --- a/lz4.c +++ b/lz4.c @@ -25,6 +25,10 @@ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + + You can contact the author at : + - LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html + - LZ4 source repository : http://code.google.com/p/lz4/ */ //************************************** diff --git a/lz4.h b/lz4.h index 10c71a4..ebd62b6 100644 --- a/lz4.h +++ b/lz4.h @@ -1,8 +1,8 @@ /* LZ4 - Fast LZ compression algorithm Header File - Copyright (C) 2011, Yann Collet. - BSD License + Copyright (C) 2011-2012, 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 @@ -26,6 +26,10 @@ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + + You can contact the author at : + - LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html + - LZ4 source repository : http://code.google.com/p/lz4/ */ #pragma once diff --git a/lz4demo.c b/lz4demo.c index e3d315d..acea04f 100644 --- a/lz4demo.c +++ b/lz4demo.c @@ -1,6 +1,7 @@ /* LZ4Demo - Demo CLI program using LZ4 compression - Copyright (C) Yann Collet 2011, + Copyright (C) Yann Collet 2011-2012 + GPL v2 License This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -45,6 +46,7 @@ #include // _O_BINARY #endif #include "lz4.h" +#include "lz4hc.h" #include "bench.h" @@ -106,9 +108,10 @@ int usage(char* exename) DISPLAY( "Usage :\n"); DISPLAY( " %s [arg] input output\n", exename); DISPLAY( "Arguments :\n"); - DISPLAY( " -c : compression (default)\n"); + DISPLAY( " -c0: Fast compression (default) \n"); + DISPLAY( " -c1: High compression \n"); DISPLAY( " -d : decompression \n"); - DISPLAY( " -b : benchmark with files\n"); + DISPLAY( " -b#: Benchmark files, using # compression level\n"); DISPLAY( " -t : check compressed file \n"); DISPLAY( " -h : help (this text)\n"); DISPLAY( "input : can be 'stdin' (pipe) or a filename\n"); @@ -159,8 +162,9 @@ int get_fileHandle(char* input_filename, char* output_filename, FILE** pfinput, -int compress_file(char* input_filename, char* output_filename) +int compress_file(char* input_filename, char* output_filename, int compressionlevel) { + int (*compressionFunction)(const char*, char*, int); unsigned long long filesize = 0; unsigned long long compressedfilesize = ARCHIVE_MAGICNUMBER_SIZE; unsigned int u32var; @@ -169,10 +173,17 @@ int compress_file(char* input_filename, char* output_filename) FILE* finput; FILE* foutput; int r; + int displayLevel = (compressionlevel>0); clock_t start, end; // Init + switch (compressionlevel) + { + case 0 : compressionFunction = LZ4_compress; break; + case 1 : compressionFunction = LZ4_compressHC; break; + default : compressionFunction = LZ4_compress; + } start = clock(); r = get_fileHandle(input_filename, output_filename, &finput, &foutput); if (r) return r; @@ -196,10 +207,12 @@ int compress_file(char* input_filename, char* output_filename) int inSize = fread(in_buff, 1, CHUNKSIZE, finput); if( inSize<=0 ) break; filesize += inSize; + if (displayLevel) DISPLAY("Read : %i MB \r", (int)(filesize>>20)); // Compress Block - outSize = LZ4_compress(in_buff, out_buff+4, inSize); + outSize = compressionFunction(in_buff, out_buff+4, inSize); compressedfilesize += outSize+4; + if (displayLevel) DISPLAY("Read : %i MB ==> %.2f%%\r", (int)(filesize>>20), (double)compressedfilesize/filesize*100); // Write Block LITTLE_ENDIAN32(outSize); @@ -300,7 +313,7 @@ int decode_file(char* input_filename, char* output_filename) int main(int argc, char** argv) { int i, - compression=1, // default action if no argument + cLevel=0, decode=0, bench=0, filenamesStart=2; @@ -334,13 +347,13 @@ int main(int argc, char** argv) if ( argument[0] =='h' ) { usage(exename); return 0; } // Compression (default) - if ( argument[0] =='c' ) { compression=1; continue; } + if ( argument[0] =='c' ) { if (argument[1] >='0') cLevel=argument[1] - '0'; continue; } // Decoding if ( argument[0] =='d' ) { decode=1; continue; } // Bench - if ( argument[0] =='b' ) { bench=1; continue; } + if ( argument[0] =='b' ) { bench=1; if (argument[1] >= '0') cLevel=argument[1] - '0'; continue; } // Modify Block Size (benchmark only) if ( argument[0] =='B' ) { int B = argument[1] - '0'; int S = 1 << (10 + 2*B); BMK_SetBlocksize(S); continue; } @@ -367,16 +380,13 @@ int main(int argc, char** argv) // No input filename ==> Error if(!input_filename) { badusage(exename); return 1; } - if (bench) return BMK_benchFile(argv+filenamesStart, argc-filenamesStart, 0); + if (bench) return BMK_benchFile(argv+filenamesStart, argc-filenamesStart, cLevel); - // No output filename + // No output filename ==> Error if (!output_filename) { badusage(exename); return 1; } if (decode) return decode_file(input_filename, output_filename); - if (compression) return compress_file(input_filename, output_filename); - - badusage(exename); + return compress_file(input_filename, output_filename, cLevel); // Compression is 'default' action - return 0; } diff --git a/lz4hc.c b/lz4hc.c new file mode 100644 index 0000000..cca755c --- /dev/null +++ b/lz4hc.c @@ -0,0 +1,663 @@ +/* + LZ4 HC - High Compression Mode of LZ4 + Copyright (C) 2011-2012, Yann Collet. + BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are + met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above + copyright notice, this list of conditions and the following disclaimer + in the documentation and/or other materials provided with the + distribution. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + + You can contact the author at : + - LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html + - LZ4 source repository : http://code.google.com/p/lz4/ +*/ + + +//************************************** +// CPU Feature Detection +//************************************** +// 32 or 64 bits ? +#if (defined(__x86_64__) || defined(__x86_64) || defined(__amd64__) || defined(__amd64) || defined(__ppc64__) || defined(_WIN64) || defined(__LP64__) || defined(_LP64) ) // Detects 64 bits mode +#define LZ4_ARCH64 1 +#else +#define LZ4_ARCH64 0 +#endif + +// Little Endian or Big Endian ? +#if (defined(__BIG_ENDIAN__) || defined(__BIG_ENDIAN) || defined(_BIG_ENDIAN) || defined(_ARCH_PPC) || defined(__PPC__) || defined(__PPC) || defined(PPC) || defined(__powerpc__) || defined(__powerpc) || defined(powerpc) || ((defined(__BYTE_ORDER__)&&(__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))) ) +#define LZ4_BIG_ENDIAN 1 +#else +// Little Endian assumed. PDP Endian and other very rare endian format are unsupported. +#endif + +// Unaligned memory access is automatically enabled for "common" CPU, such as x86. +// For others CPU, the compiler will be more cautious, and insert extra code to ensure aligned access is respected +// If you know your target CPU supports unaligned memory access, you may want to force this option manually to improve performance +#if defined(__ARM_FEATURE_UNALIGNED) +#define LZ4_FORCE_UNALIGNED_ACCESS 1 +#endif + + +//************************************** +// Compiler Options +//************************************** +#if __STDC_VERSION__ >= 199901L // C99 + /* "restrict" is a known keyword */ +#else +#define restrict // Disable restrict +#endif + +#ifdef _MSC_VER +#define inline __forceinline // Visual is not C99, but supports some kind of inline +#endif + +#ifdef _MSC_VER // Visual Studio +#define bswap16(x) _byteswap_ushort(x) +#else +#define bswap16(x) ((unsigned short int) ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8))) +#endif + + +//************************************** +// Includes +//************************************** +#include // calloc, free +#include // memset, memcpy +#include "lz4hc.h" + +#define ALLOCATOR(s) calloc(1,s) +#define FREEMEM free +#define MEM_INIT memset + + +//************************************** +// Basic Types +//************************************** +#if defined(_MSC_VER) // Visual Studio does not support 'stdint' natively +#define BYTE unsigned __int8 +#define U16 unsigned __int16 +#define U32 unsigned __int32 +#define S32 __int32 +#define U64 unsigned __int64 +#else +#include +#define BYTE uint8_t +#define U16 uint16_t +#define U32 uint32_t +#define S32 int32_t +#define U64 uint64_t +#endif + +#ifndef LZ4_FORCE_UNALIGNED_ACCESS +#pragma pack(push, 1) +#endif + +typedef struct _U16_S { U16 v; } U16_S; +typedef struct _U32_S { U32 v; } U32_S; +typedef struct _U64_S { U64 v; } U64_S; + +#ifndef LZ4_FORCE_UNALIGNED_ACCESS +#pragma pack(pop) +#endif + +#define A64(x) (((U64_S *)(x))->v) +#define A32(x) (((U32_S *)(x))->v) +#define A16(x) (((U16_S *)(x))->v) + + +//************************************** +// Constants +//************************************** +#define MINMATCH 4 + +#define DICTIONARY_LOGSIZE 16 +#define MAXD (1<> ((MINMATCH*8)-HASH_LOG)) +#define HASH_VALUE(p) HASH_FUNCTION(*(U32*)(p)) +#define HASH_POINTER(p) (HashTable[HASH_VALUE(p)] + base) +#define DELTANEXT(p) chainTable[(size_t)(p) & MAXD_MASK] +#define GETNEXT(p) ((p) - (size_t)DELTANEXT(p)) +#define ADD_HASH(p) { size_t delta = (p) - HASH_POINTER(p); if (delta>MAX_DISTANCE) delta = MAX_DISTANCE; DELTANEXT(p) = (U16)delta; HashTable[HASH_VALUE(p)] = (p) - base; } + + +//************************************** +// Private functions +//************************************** +#if LZ4_ARCH64 + +inline static int LZ4_NbCommonBytes (register U64 val) +{ +#if defined(LZ4_BIG_ENDIAN) + #if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT) + unsigned long r = 0; + _BitScanReverse64( &r, val ); + return (int)(r>>3); + #elif defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT) + return (__builtin_clzll(val) >> 3); + #else + int r; + if (!(val>>32)) { r=4; } else { r=0; val>>=32; } + if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; } + r += (!val); + return r; + #endif +#else + #if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT) + unsigned long r = 0; + _BitScanForward64( &r, val ); + return (int)(r>>3); + #elif defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT) + return (__builtin_ctzll(val) >> 3); + #else + static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2, 0, 3, 1, 3, 1, 4, 2, 7, 0, 2, 3, 6, 1, 5, 3, 5, 1, 3, 4, 4, 2, 5, 6, 7, 7, 0, 1, 2, 3, 3, 4, 6, 2, 6, 5, 5, 3, 4, 5, 6, 7, 1, 2, 4, 6, 4, 4, 5, 7, 2, 6, 5, 7, 6, 7, 7 }; + return DeBruijnBytePos[((U64)((val & -val) * 0x0218A392CDABBD3F)) >> 58]; + #endif +#endif +} + +#else + +inline static int LZ4_NbCommonBytes (register U32 val) +{ +#if defined(LZ4_BIG_ENDIAN) + #if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT) + unsigned long r = 0; + _BitScanReverse( &r, val ); + return (int)(r>>3); + #elif defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT) + return (__builtin_clz(val) >> 3); + #else + int r; + if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; } + r += (!val); + return r; + #endif +#else + #if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT) + unsigned long r = 0; + _BitScanForward( &r, val ); + return (int)(r>>3); + #elif defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT) + return (__builtin_ctz(val) >> 3); + #else + static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0, 3, 2, 2, 1, 3, 2, 0, 1, 3, 3, 1, 2, 2, 2, 2, 0, 3, 1, 2, 0, 1, 0, 1, 1 }; + return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27]; + #endif +#endif +} + +#endif + + +inline static int LZ4HC_Init (LZ4HC_Data_Structure* hc4, const BYTE* base) +{ + MEM_INIT((void*)hc4->hashTable, 0, sizeof(hc4->hashTable)); + MEM_INIT(hc4->chainTable, 0xFF, sizeof(hc4->chainTable)); + hc4->nextToUpdate = base + LZ4_ARCH64; + hc4->base = base; + return 1; +} + + +inline static void* LZ4HC_Create (const BYTE* base) +{ + void* hc4 = ALLOCATOR(sizeof(LZ4HC_Data_Structure)); + + LZ4HC_Init (hc4, base); + return hc4; +} + + +inline static int LZ4HC_Free (void** LZ4HC_Data) +{ + FREEMEM(*LZ4HC_Data); + *LZ4HC_Data = NULL; + return (1); +} + + +inline static void LZ4HC_Insert (LZ4HC_Data_Structure* hc4, const BYTE* ip) +{ + U16* chainTable = hc4->chainTable; + HTYPE* HashTable = hc4->hashTable; + INITBASE(base,hc4->base); + + while(hc4->nextToUpdate < ip) + { + ADD_HASH(hc4->nextToUpdate); + hc4->nextToUpdate++; + } +} + + +inline static int LZ4HC_InsertAndFindBestMatch (LZ4HC_Data_Structure* hc4, const BYTE* ip, const BYTE* const matchlimit, const BYTE** matchpos) +{ + U16* const chainTable = hc4->chainTable; + HTYPE* const HashTable = hc4->hashTable; + const BYTE* ref; + INITBASE(base,hc4->base); + int nbAttempts=MAX_NB_ATTEMPTS; + int ml=0; + + // HC4 match finder + LZ4HC_Insert(hc4, ip); + ref = HASH_POINTER(ip); + while ((ref > (ip-MAX_DISTANCE)) && (nbAttempts)) + { + nbAttempts--; + if (*(ref+ml) == *(ip+ml)) + if (*(U32*)ref == *(U32*)ip) + { + const BYTE* reft = ref+MINMATCH; + const BYTE* ipt = ip+MINMATCH; + + while (ipt ml) { ml = ipt-ip; *matchpos = ref; } + } + ref = GETNEXT(ref); + } + + return ml; +} + + +inline static int LZ4HC_InsertAndGetWiderMatch (LZ4HC_Data_Structure* hc4, const BYTE* ip, const BYTE* startLimit, const BYTE* matchlimit, int longest, const BYTE** matchpos, const BYTE** startpos) +{ + U16* const chainTable = hc4->chainTable; + HTYPE* const HashTable = hc4->hashTable; + INITBASE(base,hc4->base); + const BYTE* ref; + int nbAttempts = MAX_NB_ATTEMPTS; + int delta = ip-startLimit; + + // First Match + LZ4HC_Insert(hc4, ip); + ref = HASH_POINTER(ip); + + while ((ref > ip-MAX_DISTANCE) && (ref >= hc4->base) && (nbAttempts)) + { + nbAttempts--; + if (*(startLimit + longest) == *(ref - delta + longest)) + if (*(U32*)ref == *(U32*)ip) + { + const BYTE* reft = ref+MINMATCH; + const BYTE* ipt = ip+MINMATCH; + const BYTE* startt = ip; + + while (iptstartLimit) && (reft > hc4->base) && (startt[-1] == reft[-1])) {startt--; reft--;} + + if ((ipt-startt) > longest) + { + longest = ipt-startt; + *matchpos = reft; + *startpos = startt; + } + } + ref = GETNEXT(ref); + } + + return longest; +} + + +inline static int LZ4_encodeSequence(const BYTE** ip, BYTE** op, const BYTE** anchor, int ml, const BYTE* ref) +{ + int length, len; + BYTE* token; + + // Encode Literal length + length = *ip - *anchor; + token = (*op)++; + if (length>=(int)RUN_MASK) { *token=(RUN_MASK< 254 ; len-=255) *(*op)++ = 255; *(*op)++ = (BYTE)len; } + else *token = (length<=(int)ML_MASK) { *token+=ML_MASK; len-=ML_MASK; for(; len > 509 ; len-=510) { *(*op)++ = 255; *(*op)++ = 255; } if (len > 254) { len-=255; *(*op)++ = 255; } *(*op)++ = (BYTE)len; } + else *token += len; + + // Prepare next loop + *ip += ml; + *anchor = *ip; + + return 0; +} + + +//**************************** +// Compression CODE +//**************************** + +int LZ4_compressHCCtx(LZ4HC_Data_Structure* ctx, + const char* source, + char* dest, + int isize) +{ + const BYTE* ip = (const BYTE*) source; + const BYTE* anchor = ip; + const BYTE* const iend = ip + isize; + const BYTE* const mflimit = iend - MFLIMIT; + const BYTE* const matchlimit = (iend - LASTLITERALS); + + BYTE* op = (BYTE*) dest; + + 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; + + ip++; + + // Main Loop + while (ip < mflimit) + { + ml = LZ4HC_InsertAndFindBestMatch (ctx, ip, matchlimit, (&ref)); + if (!ml) { ip++; continue; } + + // saved, in case we would skip too much + start0 = ip; + ref0 = ref; + ml0 = ml; + +_Search2: + if (ip+ml < mflimit) + ml2 = LZ4HC_InsertAndGetWiderMatch(ctx, ip + ml - 2, ip + 1, matchlimit, ml, &ref2, &start2); + else ml2=ml; + + if (ml2 == ml) // No better match + { + LZ4_encodeSequence(&ip, &op, &anchor, ml, ref); + continue; + } + + if (start0 < ip) + { + if (start2 < ip + ml0) // empirical + { + ip = start0; + ref = ref0; + ml = ml0; + } + } + + // Here, start0==ip + if ((start2 - ip) < 3) // First Match too small : removed + { + ml = ml2; + ip = start2; + ref =ref2; + goto _Search2; + } + +_Search3: + // Currently we have : + // ml2 > ml1, and + // ip1+3 <= ip2 (usually < ip1+ml1) + if ((start2 - ip) < OPTIMAL_ML) + { + int correction; + int new_ml = ml; + if (new_ml > OPTIMAL_ML) new_ml = OPTIMAL_ML; + if (ip+new_ml > start2 + ml2 - MINMATCH) new_ml = start2 - ip + ml2 - MINMATCH; + correction = new_ml - (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); + else ml3=ml2; + + if (ml3 == ml2) // No better match : 2 sequences to encode + { + // ip & ref are known; Now for 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 = start2 - ip + ml2 - MINMATCH; + correction = ml - (start2 - ip); + if (correction > 0) + { + start2 += correction; + ref2 += correction; + ml2 -= correction; + } + } + else + { + ml = start2 - ip; + } + } + // Now, encode 2 sequences + LZ4_encodeSequence(&ip, &op, &anchor, ml, ref); + ip = start2; + LZ4_encodeSequence(&ip, &op, &anchor, ml2, ref2); + 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 = (ip+ml) - start2; + start2 += correction; + ref2 += correction; + ml2 -= correction; + if (ml2 < MINMATCH) + { + start2 = start3; + ref2 = ref3; + ml2 = ml3; + } + } + + LZ4_encodeSequence(&ip, &op, &anchor, ml, ref); + 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 = start2 - ip + ml2 - MINMATCH; + correction = ml - (start2 - ip); + if (correction > 0) + { + start2 += correction; + ref2 += correction; + ml2 -= correction; + } + } + else + { + ml = start2 - ip; + } + } + LZ4_encodeSequence(&ip, &op, &anchor, ml, ref); + + ip = start2; + ref = ref2; + ml = ml2; + + start2 = start3; + ref2 = ref3; + ml2 = ml3; + + goto _Search3; + + } + + // Encode Last Literals + { + int lastRun = iend - anchor; + if (lastRun>=(int)RUN_MASK) { *op++=(RUN_MASK< 254 ; lastRun-=255) *op++ = 255; *op++ = (BYTE) lastRun; } + else *op++ = (lastRun<