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pcompress/lz4/lz4hc.c

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Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
2012-07-25 15:37:36 +00:00
/*
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
Update to latest LZ4. Update a couple of comments.
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#include <intrin.h> // For Visual 2005
# if LZ4_ARCH64 // 64-bit
# pragma intrinsic(_BitScanForward64) // For Visual 2005
# pragma intrinsic(_BitScanReverse64) // For Visual 2005
# else
# pragma intrinsic(_BitScanForward) // For Visual 2005
# pragma intrinsic(_BitScanReverse) // For Visual 2005
# endif
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
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#endif
#ifdef _MSC_VER // Visual Studio
Update to latest LZ4. Update a couple of comments.
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#define lz4_bswap16(x) _byteswap_ushort(x)
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
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#else
Update to latest LZ4. Update a couple of comments.
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#define lz4_bswap16(x) ((unsigned short int) ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8)))
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
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#endif
//**************************************
// Includes
//**************************************
#include <stdlib.h> // calloc, free
#include <string.h> // memset, memcpy
Fix buffer size calculation when decompressing LZ4, Zlib and Bzip2 compressed chunks. Slight SSE optimization in LZ4HC.
2012-08-03 17:49:38 +00:00
#ifdef __USE_SSE_INTRIN__
#include <emmintrin.h>
#endif
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
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#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 <stdint.h>
#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<<DICTIONARY_LOGSIZE)
#define MAXD_MASK ((U32)(MAXD - 1))
#define MAX_DISTANCE (MAXD - 1)
#define HASH_LOG (DICTIONARY_LOGSIZE-1)
#define HASHTABLESIZE (1 << HASH_LOG)
#define HASH_MASK (HASHTABLESIZE - 1)
#define MAX_NB_ATTEMPTS 256
#define ML_BITS 4
#define ML_MASK (size_t)((1U<<ML_BITS)-1)
#define RUN_BITS (8-ML_BITS)
#define RUN_MASK ((1U<<RUN_BITS)-1)
#define COPYLENGTH 8
#define LASTLITERALS 5
#define MFLIMIT (COPYLENGTH+MINMATCH)
#define MINLENGTH (MFLIMIT+1)
#define OPTIMAL_ML (int)((ML_MASK-1)+MINMATCH)
//**************************************
// Architecture-specific macros
//**************************************
#if LZ4_ARCH64 // 64-bit
#define STEPSIZE 8
#define LZ4_COPYSTEP(s,d) A64(d) = A64(s); d+=8; s+=8;
#define LZ4_COPYPACKET(s,d) LZ4_COPYSTEP(s,d)
#define UARCH U64
#define AARCH A64
#define HTYPE U32
#define INITBASE(b,s) const BYTE* const b = s
#else // 32-bit
#define STEPSIZE 4
#define LZ4_COPYSTEP(s,d) A32(d) = A32(s); d+=4; s+=4;
#define LZ4_COPYPACKET(s,d) LZ4_COPYSTEP(s,d); LZ4_COPYSTEP(s,d);
#define UARCH U32
#define AARCH A32
#define HTYPE const BYTE*
#define INITBASE(b,s) const int b = 0
#endif
#if defined(LZ4_BIG_ENDIAN)
Update to latest LZ4. Update a couple of comments.
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#define LZ4_READ_LITTLEENDIAN_16(d,s,p) { U16 v = A16(p); v = lz4_bswap16(v); d = (s) - v; }
#define LZ4_WRITE_LITTLEENDIAN_16(p,i) { U16 v = (U16)(i); v = lz4_bswap16(v); A16(p) = v; p+=2; }
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
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#else // Little Endian
#define LZ4_READ_LITTLEENDIAN_16(d,s,p) { d = (s) - A16(p); }
#define LZ4_WRITE_LITTLEENDIAN_16(p,v) { A16(p) = v; p+=2; }
#endif
//************************************************************
// Local Types
//************************************************************
typedef struct
{
const BYTE* base;
HTYPE hashTable[HASHTABLESIZE];
U16 chainTable[MAXD];
const BYTE* nextToUpdate;
} LZ4HC_Data_Structure;
//**************************************
// Macros
//**************************************
#define LZ4_WILDCOPY(s,d,e) do { LZ4_COPYPACKET(s,d) } while (d<e);
#define LZ4_BLINDCOPY(s,d,l) { BYTE* e=d+l; LZ4_WILDCOPY(s,d,e); d=e; }
#define HASH_FUNCTION(i) (((i) * 2654435761U) >> ((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;
}
Introduce strict compiler flags and fix scores of warnings/issues. Avoid different optimization flags for Dedupe sources. Fix liberal mixing of uint64_t and int64_t (should all be uint64_t). Fix corner case crash when decompressing.
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inline static LZ4HC_Data_Structure* LZ4HC_Create (const BYTE* base)
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
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{
Introduce strict compiler flags and fix scores of warnings/issues. Avoid different optimization flags for Dedupe sources. Fix liberal mixing of uint64_t and int64_t (should all be uint64_t). Fix corner case crash when decompressing.
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LZ4HC_Data_Structure* hc4 = (LZ4HC_Data_Structure *)ALLOCATOR(sizeof(LZ4HC_Data_Structure));
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
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LZ4HC_Init (hc4, base);
return hc4;
}
Introduce strict compiler flags and fix scores of warnings/issues. Avoid different optimization flags for Dedupe sources. Fix liberal mixing of uint64_t and int64_t (should all be uint64_t). Fix corner case crash when decompressing.
2012-12-27 17:36:48 +00:00
inline static int LZ4HC_Free (LZ4HC_Data_Structure** LZ4HC_Data)
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
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{
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);
Update to latest LZ4. Update a couple of comments.
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while ((ref >= (ip-MAX_DISTANCE)) && (nbAttempts))
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
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{
nbAttempts--;
if (*(ref+ml) == *(ip+ml))
if (*(U32*)ref == *(U32*)ip)
{
const BYTE* reft = ref+MINMATCH;
const BYTE* ipt = ip+MINMATCH;
Fix buffer size calculation when decompressing LZ4, Zlib and Bzip2 compressed chunks. Slight SSE optimization in LZ4HC.
2012-08-03 17:49:38 +00:00
#ifdef __USE_SSE_INTRIN__
Update to latest LZ4. Update a couple of comments.
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while (ipt<matchlimit-15) {
int mask;
__m128i span1 = _mm_loadu_si128((__m128i *)(reft));
__m128i span2 = _mm_loadu_si128((__m128i *)(ipt));
mask = _mm_movemask_epi8(_mm_cmpeq_epi8(span1, span2)) ^ 0xffff;
if (!mask) { ipt+=16; reft+=16; continue; }
ipt += __builtin_ctz(mask);
goto _endCount;
}
Fix buffer size calculation when decompressing LZ4, Zlib and Bzip2 compressed chunks. Slight SSE optimization in LZ4HC.
2012-08-03 17:49:38 +00:00
#endif
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
2012-07-25 15:37:36 +00:00
while (ipt<matchlimit-(STEPSIZE-1))
{
UARCH diff = AARCH(reft) ^ AARCH(ipt);
if (!diff) { ipt+=STEPSIZE; reft+=STEPSIZE; continue; }
ipt += LZ4_NbCommonBytes(diff);
goto _endCount;
}
if (LZ4_ARCH64) if ((ipt<(matchlimit-3)) && (A32(reft) == A32(ipt))) { ipt+=4; reft+=4; }
if ((ipt<(matchlimit-1)) && (A16(reft) == A16(ipt))) { ipt+=2; reft+=2; }
if ((ipt<matchlimit) && (*reft == *ipt)) ipt++;
_endCount:
Update to latest LZ4. Update a couple of comments.
2012-12-11 06:08:42 +00:00
if (ipt-ip > ml) { ml = (int)(ipt-ip); *matchpos = ref; }
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
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}
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;
Update to latest LZ4. Update a couple of comments.
2012-12-11 06:08:42 +00:00
int delta = (int)(ip-startLimit);
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
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// First Match
LZ4HC_Insert(hc4, ip);
ref = HASH_POINTER(ip);
Update to latest LZ4. Update a couple of comments.
2012-12-11 06:08:42 +00:00
while ((ref >= ip-MAX_DISTANCE) && (ref >= hc4->base) && (nbAttempts))
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
2012-07-25 15:37:36 +00:00
{
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;
Fix buffer size calculation when decompressing LZ4, Zlib and Bzip2 compressed chunks. Slight SSE optimization in LZ4HC.
2012-08-03 17:49:38 +00:00
#ifdef __USE_SSE_INTRIN__
Update to latest LZ4. Update a couple of comments.
2012-12-11 06:08:42 +00:00
while (ipt<matchlimit-15) {
int mask;
__m128i span1 = _mm_loadu_si128((__m128i *)(reft));
__m128i span2 = _mm_loadu_si128((__m128i *)(ipt));
mask = _mm_movemask_epi8(_mm_cmpeq_epi8(span1, span2)) ^ 0xffff;
if (!mask) { ipt+=16; reft+=16; continue; }
ipt += __builtin_ctz(mask);
goto _endCount;
}
Fix buffer size calculation when decompressing LZ4, Zlib and Bzip2 compressed chunks. Slight SSE optimization in LZ4HC.
2012-08-03 17:49:38 +00:00
#endif
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
2012-07-25 15:37:36 +00:00
while (ipt<matchlimit-(STEPSIZE-1))
{
UARCH diff = AARCH(reft) ^ AARCH(ipt);
if (!diff) { ipt+=STEPSIZE; reft+=STEPSIZE; continue; }
ipt += LZ4_NbCommonBytes(diff);
goto _endCount;
}
if (LZ4_ARCH64) if ((ipt<(matchlimit-3)) && (A32(reft) == A32(ipt))) { ipt+=4; reft+=4; }
if ((ipt<(matchlimit-1)) && (A16(reft) == A16(ipt))) { ipt+=2; reft+=2; }
if ((ipt<matchlimit) && (*reft == *ipt)) ipt++;
_endCount:
reft = ref;
while ((startt>startLimit) && (reft > hc4->base) && (startt[-1] == reft[-1])) {startt--; reft--;}
if ((ipt-startt) > longest)
{
Update to latest LZ4. Update a couple of comments.
2012-12-11 06:08:42 +00:00
longest = (int)(ipt-startt);
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
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*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
Update to latest LZ4. Update a couple of comments.
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length = (int)(*ip - *anchor);
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
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token = (*op)++;
if (length>=(int)RUN_MASK) { *token=(RUN_MASK<<ML_BITS); len = length-RUN_MASK; for(; len > 254 ; len-=255) *(*op)++ = 255; *(*op)++ = (BYTE)len; }
else *token = (length<<ML_BITS);
// Copy Literals
LZ4_BLINDCOPY(*anchor, *op, length);
// Encode Offset
Update to latest LZ4. Update a couple of comments.
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LZ4_WRITE_LITTLEENDIAN_16(*op,(U16)(*ip-ref));
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
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// Encode MatchLength
len = (int)(ml-MINMATCH);
if (len>=(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;
Update to latest LZ4. Update a couple of comments.
2012-12-11 06:08:42 +00:00
if (ip+new_ml > start2 + ml2 - MINMATCH) new_ml = (int)(start2 - ip) + ml2 - MINMATCH;
correction = new_ml - (int)(start2 - ip);
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
2012-07-25 15:37:36 +00:00
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;
Update to latest LZ4. Update a couple of comments.
2012-12-11 06:08:42 +00:00
if (ip+ml > start2 + ml2 - MINMATCH) ml = (int)(start2 - ip) + ml2 - MINMATCH;
correction = ml - (int)(start2 - ip);
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
2012-07-25 15:37:36 +00:00
if (correction > 0)
{
start2 += correction;
ref2 += correction;
ml2 -= correction;
}
}
else
{
Update to latest LZ4. Update a couple of comments.
2012-12-11 06:08:42 +00:00
ml = (int)(start2 - ip);
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
2012-07-25 15:37:36 +00:00
}
}
// 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)
{
Update to latest LZ4. Update a couple of comments.
2012-12-11 06:08:42 +00:00
int correction = (int)(ip+ml - start2);
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
2012-07-25 15:37:36 +00:00
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;
Update to latest LZ4. Update a couple of comments.
2012-12-11 06:08:42 +00:00
if (ip + ml > start2 + ml2 - MINMATCH) ml = (int)(start2 - ip) + ml2 - MINMATCH;
correction = ml - (int)(start2 - ip);
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
2012-07-25 15:37:36 +00:00
if (correction > 0)
{
start2 += correction;
ref2 += correction;
ml2 -= correction;
}
}
else
{
Update to latest LZ4. Update a couple of comments.
2012-12-11 06:08:42 +00:00
ml = (int)(start2 - ip);
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
2012-07-25 15:37:36 +00:00
}
}
LZ4_encodeSequence(&ip, &op, &anchor, ml, ref);
ip = start2;
ref = ref2;
ml = ml2;
start2 = start3;
ref2 = ref3;
ml2 = ml3;
goto _Search3;
}
// Encode Last Literals
{
Update to latest LZ4. Update a couple of comments.
2012-12-11 06:08:42 +00:00
int lastRun = (int)(iend - anchor);
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
2012-07-25 15:37:36 +00:00
if (lastRun>=(int)RUN_MASK) { *op++=(RUN_MASK<<ML_BITS); lastRun-=RUN_MASK; for(; lastRun > 254 ; lastRun-=255) *op++ = 255; *op++ = (BYTE) lastRun; }
else *op++ = (lastRun<<ML_BITS);
memcpy(op, anchor, iend - anchor);
op += iend-anchor;
}
// End
return (int) (((char*)op)-dest);
}
int LZ4_compressHC(const char* source,
char* dest,
int isize)
{
Introduce strict compiler flags and fix scores of warnings/issues. Avoid different optimization flags for Dedupe sources. Fix liberal mixing of uint64_t and int64_t (should all be uint64_t). Fix corner case crash when decompressing.
2012-12-27 17:36:48 +00:00
LZ4HC_Data_Structure* ctx = LZ4HC_Create((const BYTE*)source);
Add support for LZ4 compression including multi-pass LZ4. Add missing Read_Adjusted() declaration, was causing a crash with 2GB chunks. Fix minor cut-paste issues in comments.
2012-07-25 15:37:36 +00:00
int result = LZ4_compressHCCtx(ctx, source, dest, isize);
LZ4HC_Free (&ctx);
return result;
}
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