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lz4.c
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lz4.c
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/*
LZ4 - Fast LZ compression algorithm
Copyright (C) 2011-2015, 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/Cyan4973/lz4
- LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
*/
/**************************************
* Tuning parameters
**************************************/
/*
* HEAPMODE :
* Select how default compression functions will allocate memory for their hash table,
* in memory stack (0:default, fastest), or in memory heap (1:requires malloc()).
*/
#define HEAPMODE 0
/*
* ACCELERATION_DEFAULT :
* Select the value of "acceleration" for LZ4_compress_fast() when parameter == 0
*/
#define ACCELERATION_DEFAULT 1
/**************************************
* CPU Feature Detection
**************************************/
/*
* LZ4_FORCE_SW_BITCOUNT
* Define this parameter if your target system or compiler does not support hardware bit count
*/
#if defined(_MSC_VER) && defined(_WIN32_WCE) /* Visual Studio for Windows CE does not support Hardware bit count */
# define LZ4_FORCE_SW_BITCOUNT
#endif
/**************************************
* Includes
**************************************/
#include "lz4.h"
/**************************************
* Compiler Options
**************************************/
#ifdef _MSC_VER /* Visual Studio */
# define FORCE_INLINE static __forceinline
# include <intrin.h>
# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
# pragma warning(disable : 4293) /* disable: C4293: too large shift (32-bits) */
#else
# if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */
# if defined(__GNUC__) || defined(__clang__)
# define FORCE_INLINE static inline __attribute__((always_inline))
# else
# define FORCE_INLINE static inline
# endif
# else
# define FORCE_INLINE static
# endif /* __STDC_VERSION__ */
#endif /* _MSC_VER */
/* LZ4_GCC_VERSION is defined into lz4.h */
#if (LZ4_GCC_VERSION >= 302) || (__INTEL_COMPILER >= 800) || defined(__clang__)
# define expect(expr,value) (__builtin_expect ((expr),(value)) )
#else
# define expect(expr,value) (expr)
#endif
#define likely(expr) expect((expr) != 0, 1)
#define unlikely(expr) expect((expr) != 0, 0)
/**************************************
* Memory routines
**************************************/
#include <stdlib.h> /* malloc, calloc, free */
#define ALLOCATOR(n,s) calloc(n,s)
#define FREEMEM free
#include <string.h> /* memset, memcpy */
#define MEM_INIT memset
/**************************************
* Basic Types
**************************************/
#if defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */
# include <stdint.h>
typedef uint8_t BYTE;
typedef uint16_t U16;
typedef uint32_t U32;
typedef int32_t S32;
typedef uint64_t U64;
#else
typedef unsigned char BYTE;
typedef unsigned short U16;
typedef unsigned int U32;
typedef signed int S32;
typedef unsigned long long U64;
#endif
/**************************************
* Reading and writing into memory
**************************************/
#define STEPSIZE sizeof(size_t)
static unsigned LZ4_64bits(void) { return sizeof(void*)==8; }
static unsigned LZ4_isLittleEndian(void)
{
const union { U32 i; BYTE c[4]; } one = { 1 }; /* don't use static : performance detrimental */
return one.c[0];
}
static U16 LZ4_read16(const void* memPtr)
{
U16 val16;
memcpy(&val16, memPtr, 2);
return val16;
}
static U16 LZ4_readLE16(const void* memPtr)
{
if (LZ4_isLittleEndian())
{
return LZ4_read16(memPtr);
}
else
{
const BYTE* p = (const BYTE*)memPtr;
return (U16)((U16)p[0] + (p[1]<<8));
}
}
static void LZ4_writeLE16(void* memPtr, U16 value)
{
if (LZ4_isLittleEndian())
{
memcpy(memPtr, &value, 2);
}
else
{
BYTE* p = (BYTE*)memPtr;
p[0] = (BYTE) value;
p[1] = (BYTE)(value>>8);
}
}
static U32 LZ4_read32(const void* memPtr)
{
U32 val32;
memcpy(&val32, memPtr, 4);
return val32;
}
static U64 LZ4_read64(const void* memPtr)
{
U64 val64;
memcpy(&val64, memPtr, 8);
return val64;
}
static size_t LZ4_read_ARCH(const void* p)
{
if (LZ4_64bits())
return (size_t)LZ4_read64(p);
else
return (size_t)LZ4_read32(p);
}
static void LZ4_copy4(void* dstPtr, const void* srcPtr) { memcpy(dstPtr, srcPtr, 4); }
static void LZ4_copy8(void* dstPtr, const void* srcPtr) { memcpy(dstPtr, srcPtr, 8); }
/* customized version of memcpy, which may overwrite up to 7 bytes beyond dstEnd */
static void LZ4_wildCopy(void* dstPtr, const void* srcPtr, void* dstEnd)
{
BYTE* d = (BYTE*)dstPtr;
const BYTE* s = (const BYTE*)srcPtr;
BYTE* e = (BYTE*)dstEnd;
do { LZ4_copy8(d,s); d+=8; s+=8; } while (d<e);
}
/**************************************
* Common Constants
**************************************/
#define MINMATCH 4
#define COPYLENGTH 8
#define LASTLITERALS 5
#define MFLIMIT (COPYLENGTH+MINMATCH)
static const int LZ4_minLength = (MFLIMIT+1);
#define KB *(1 <<10)
#define MB *(1 <<20)
#define GB *(1U<<30)
#define MAXD_LOG 16
#define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
#define ML_BITS 4
#define ML_MASK ((1U<<ML_BITS)-1)
#define RUN_BITS (8-ML_BITS)
#define RUN_MASK ((1U<<RUN_BITS)-1)
/**************************************
* Common Utils
**************************************/
#define LZ4_STATIC_ASSERT(c) { enum { LZ4_static_assert = 1/(int)(!!(c)) }; } /* use only *after* variable declarations */
/**************************************
* Common functions
**************************************/
static unsigned LZ4_NbCommonBytes (register size_t val)
{
if (LZ4_isLittleEndian())
{
if (LZ4_64bits())
{
# if defined(_MSC_VER) && defined(_WIN64) && !defined(LZ4_FORCE_SW_BITCOUNT)
unsigned long r = 0;
_BitScanForward64( &r, (U64)val );
return (int)(r>>3);
# elif (defined(__clang__) || (LZ4_GCC_VERSION >= 304)) && !defined(LZ4_FORCE_SW_BITCOUNT)
return (__builtin_ctzll((U64)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 & -(long long)val) * 0x0218A392CDABBD3FULL)) >> 58];
# endif
}
else /* 32 bits */
{
# if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
unsigned long r;
_BitScanForward( &r, (U32)val );
return (int)(r>>3);
# elif (defined(__clang__) || (LZ4_GCC_VERSION >= 304)) && !defined(LZ4_FORCE_SW_BITCOUNT)
return (__builtin_ctz((U32)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
}
}
else /* Big Endian CPU */
{
if (LZ4_64bits())
{
# if defined(_MSC_VER) && defined(_WIN64) && !defined(LZ4_FORCE_SW_BITCOUNT)
unsigned long r = 0;
_BitScanReverse64( &r, val );
return (unsigned)(r>>3);
# elif (defined(__clang__) || (LZ4_GCC_VERSION >= 304)) && !defined(LZ4_FORCE_SW_BITCOUNT)
return (__builtin_clzll((U64)val) >> 3);
# else
unsigned 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 /* 32 bits */
{
# if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
unsigned long r = 0;
_BitScanReverse( &r, (unsigned long)val );
return (unsigned)(r>>3);
# elif (defined(__clang__) || (LZ4_GCC_VERSION >= 304)) && !defined(LZ4_FORCE_SW_BITCOUNT)
return (__builtin_clz((U32)val) >> 3);
# else
unsigned r;
if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
r += (!val);
return r;
# endif
}
}
}
static unsigned LZ4_count(const BYTE* pIn, const BYTE* pMatch, const BYTE* pInLimit)
{
const BYTE* const pStart = pIn;
while (likely(pIn<pInLimit-(STEPSIZE-1)))
{
size_t diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn);
if (!diff) { pIn+=STEPSIZE; pMatch+=STEPSIZE; continue; }
pIn += LZ4_NbCommonBytes(diff);
return (unsigned)(pIn - pStart);
}
if (LZ4_64bits()) if ((pIn<(pInLimit-3)) && (LZ4_read32(pMatch) == LZ4_read32(pIn))) { pIn+=4; pMatch+=4; }
if ((pIn<(pInLimit-1)) && (LZ4_read16(pMatch) == LZ4_read16(pIn))) { pIn+=2; pMatch+=2; }
if ((pIn<pInLimit) && (*pMatch == *pIn)) pIn++;
return (unsigned)(pIn - pStart);
}
#ifndef LZ4_COMMONDEFS_ONLY
/**************************************
* Local Constants
**************************************/
#define LZ4_HASHLOG (LZ4_MEMORY_USAGE-2)
#define HASHTABLESIZE (1 << LZ4_MEMORY_USAGE)
#define HASH_SIZE_U32 (1 << LZ4_HASHLOG) /* required as macro for static allocation */
static const int LZ4_64Klimit = ((64 KB) + (MFLIMIT-1));
static const U32 LZ4_skipTrigger = 6; /* Increase this value ==> compression run slower on incompressible data */
/**************************************
* Local Structures and types
**************************************/
typedef struct {
U32 hashTable[HASH_SIZE_U32];
U32 currentOffset;
U32 initCheck;
const BYTE* dictionary;
BYTE* bufferStart; /* obsolete, used for slideInputBuffer */
U32 dictSize;
} LZ4_stream_t_internal;
typedef enum { notLimited = 0, limitedOutput = 1 } limitedOutput_directive;
typedef enum { byPtr, byU32, byU16 } tableType_t;
typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive;
typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
typedef enum { full = 0, partial = 1 } earlyEnd_directive;
/**************************************
* Local Utils
**************************************/
int LZ4_versionNumber (void) { return LZ4_VERSION_NUMBER; }
int LZ4_compressBound(int isize) { return LZ4_COMPRESSBOUND(isize); }
int LZ4_sizeofState() { return LZ4_STREAMSIZE; }
/********************************
* Compression functions
********************************/
static U32 LZ4_hashSequence(U32 sequence, tableType_t const tableType)
{
if (tableType == byU16)
return (((sequence) * 2654435761U) >> ((MINMATCH*8)-(LZ4_HASHLOG+1)));
else
return (((sequence) * 2654435761U) >> ((MINMATCH*8)-LZ4_HASHLOG));
}
static const U64 prime5bytes = 889523592379ULL;
static U32 LZ4_hashSequence64(size_t sequence, tableType_t const tableType)
{
const U32 hashLog = (tableType == byU16) ? LZ4_HASHLOG+1 : LZ4_HASHLOG;
const U32 hashMask = (1<<hashLog) - 1;
return ((sequence * prime5bytes) >> (40 - hashLog)) & hashMask;
}
static U32 LZ4_hashSequenceT(size_t sequence, tableType_t const tableType)
{
if (LZ4_64bits())
return LZ4_hashSequence64(sequence, tableType);
return LZ4_hashSequence((U32)sequence, tableType);
}
static U32 LZ4_hashPosition(const void* p, tableType_t tableType) { return LZ4_hashSequenceT(LZ4_read_ARCH(p), tableType); }
static void LZ4_putPositionOnHash(const BYTE* p, U32 h, void* tableBase, tableType_t const tableType, const BYTE* srcBase)
{
switch (tableType)
{
case byPtr: { const BYTE** hashTable = (const BYTE**)tableBase; hashTable[h] = p; return; }
case byU32: { U32* hashTable = (U32*) tableBase; hashTable[h] = (U32)(p-srcBase); return; }
case byU16: { U16* hashTable = (U16*) tableBase; hashTable[h] = (U16)(p-srcBase); return; }
}
}
static void LZ4_putPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
{
U32 h = LZ4_hashPosition(p, tableType);
LZ4_putPositionOnHash(p, h, tableBase, tableType, srcBase);
}
static const BYTE* LZ4_getPositionOnHash(U32 h, void* tableBase, tableType_t tableType, const BYTE* srcBase)
{
if (tableType == byPtr) { const BYTE** hashTable = (const BYTE**) tableBase; return hashTable[h]; }
if (tableType == byU32) { U32* hashTable = (U32*) tableBase; return hashTable[h] + srcBase; }
{ U16* hashTable = (U16*) tableBase; return hashTable[h] + srcBase; } /* default, to ensure a return */
}
static const BYTE* LZ4_getPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
{
U32 h = LZ4_hashPosition(p, tableType);
return LZ4_getPositionOnHash(h, tableBase, tableType, srcBase);
}
static int LZ4_compress_generic(
void* const ctx,
const char* const source,
char* const dest,
const int inputSize,
const int maxOutputSize,
const limitedOutput_directive outputLimited,
const tableType_t tableType,
const dict_directive dict,
const dictIssue_directive dictIssue,
const U32 acceleration)
{
LZ4_stream_t_internal* const dictPtr = (LZ4_stream_t_internal*)ctx;
const BYTE* ip = (const BYTE*) source;
const BYTE* base;
const BYTE* lowLimit;
const BYTE* const lowRefLimit = ip - dictPtr->dictSize;
const BYTE* const dictionary = dictPtr->dictionary;
const BYTE* const dictEnd = dictionary + dictPtr->dictSize;
const size_t dictDelta = dictEnd - (const BYTE*)source;
const BYTE* anchor = (const BYTE*) source;
const BYTE* const iend = ip + inputSize;
const BYTE* const mflimit = iend - MFLIMIT;
const BYTE* const matchlimit = iend - LASTLITERALS;
BYTE* op = (BYTE*) dest;
BYTE* const olimit = op + maxOutputSize;
U32 forwardH;
size_t refDelta=0;
/* Init conditions */
if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size, too large (or negative) */
switch(dict)
{
case noDict:
default:
base = (const BYTE*)source;
lowLimit = (const BYTE*)source;
break;
case withPrefix64k:
base = (const BYTE*)source - dictPtr->currentOffset;
lowLimit = (const BYTE*)source - dictPtr->dictSize;
break;
case usingExtDict:
base = (const BYTE*)source - dictPtr->currentOffset;
lowLimit = (const BYTE*)source;
break;
}
if ((tableType == byU16) && (inputSize>=LZ4_64Klimit)) return 0; /* Size too large (not within 64K limit) */
if (inputSize<LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */
/* First Byte */
LZ4_putPosition(ip, ctx, tableType, base);
ip++; forwardH = LZ4_hashPosition(ip, tableType);
/* Main Loop */
for ( ; ; )
{
const BYTE* match;
BYTE* token;
{
const BYTE* forwardIp = ip;
unsigned step = 1;
unsigned searchMatchNb = acceleration << LZ4_skipTrigger;
/* Find a match */
do {
U32 h = forwardH;
ip = forwardIp;
forwardIp += step;
step = (searchMatchNb++ >> LZ4_skipTrigger);
if (unlikely(forwardIp > mflimit)) goto _last_literals;
match = LZ4_getPositionOnHash(h, ctx, tableType, base);
if (dict==usingExtDict)
{
if (match<(const BYTE*)source)
{
refDelta = dictDelta;
lowLimit = dictionary;
}
else
{
refDelta = 0;
lowLimit = (const BYTE*)source;
}
}
forwardH = LZ4_hashPosition(forwardIp, tableType);
LZ4_putPositionOnHash(ip, h, ctx, tableType, base);
} while ( ((dictIssue==dictSmall) ? (match < lowRefLimit) : 0)
|| ((tableType==byU16) ? 0 : (match + MAX_DISTANCE < ip))
|| (LZ4_read32(match+refDelta) != LZ4_read32(ip)) );
}
/* Catch up */
while ((ip>anchor) && (match+refDelta > lowLimit) && (unlikely(ip[-1]==match[refDelta-1]))) { ip--; match--; }
{
/* Encode Literal length */
unsigned litLength = (unsigned)(ip - anchor);
token = op++;
if ((outputLimited) && (unlikely(op + litLength + (2 + 1 + LASTLITERALS) + (litLength/255) > olimit)))
return 0; /* Check output limit */
if (litLength>=RUN_MASK)
{
int len = (int)litLength-RUN_MASK;
*token=(RUN_MASK<<ML_BITS);
for(; len >= 255 ; len-=255) *op++ = 255;
*op++ = (BYTE)len;
}
else *token = (BYTE)(litLength<<ML_BITS);
/* Copy Literals */
LZ4_wildCopy(op, anchor, op+litLength);
op+=litLength;
}
_next_match:
/* Encode Offset */
LZ4_writeLE16(op, (U16)(ip-match)); op+=2;
/* Encode MatchLength */
{
unsigned matchLength;
if ((dict==usingExtDict) && (lowLimit==dictionary))
{
const BYTE* limit;
match += refDelta;
limit = ip + (dictEnd-match);
if (limit > matchlimit) limit = matchlimit;
matchLength = LZ4_count(ip+MINMATCH, match+MINMATCH, limit);
ip += MINMATCH + matchLength;
if (ip==limit)
{
unsigned more = LZ4_count(ip, (const BYTE*)source, matchlimit);
matchLength += more;
ip += more;
}
}
else
{
matchLength = LZ4_count(ip+MINMATCH, match+MINMATCH, matchlimit);
ip += MINMATCH + matchLength;
}
if ((outputLimited) && (unlikely(op + (1 + LASTLITERALS) + (matchLength>>8) > olimit)))
return 0; /* Check output limit */
if (matchLength>=ML_MASK)
{
*token += ML_MASK;
matchLength -= ML_MASK;
for (; matchLength >= 510 ; matchLength-=510) { *op++ = 255; *op++ = 255; }
if (matchLength >= 255) { matchLength-=255; *op++ = 255; }
*op++ = (BYTE)matchLength;
}
else *token += (BYTE)(matchLength);
}
anchor = ip;
/* Test end of chunk */
if (ip > mflimit) break;
/* Fill table */
LZ4_putPosition(ip-2, ctx, tableType, base);
/* Test next position */
match = LZ4_getPosition(ip, ctx, tableType, base);
if (dict==usingExtDict)
{
if (match<(const BYTE*)source)
{
refDelta = dictDelta;
lowLimit = dictionary;
}
else
{
refDelta = 0;
lowLimit = (const BYTE*)source;
}
}
LZ4_putPosition(ip, ctx, tableType, base);
if ( ((dictIssue==dictSmall) ? (match>=lowRefLimit) : 1)
&& (match+MAX_DISTANCE>=ip)
&& (LZ4_read32(match+refDelta)==LZ4_read32(ip)) )
{ token=op++; *token=0; goto _next_match; }
/* Prepare next loop */
forwardH = LZ4_hashPosition(++ip, tableType);
}
_last_literals:
/* Encode Last Literals */
{
const size_t lastRun = (size_t)(iend - anchor);
if ((outputLimited) && ((op - (BYTE*)dest) + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > (U32)maxOutputSize))
return 0; /* Check output limit */
if (lastRun >= RUN_MASK)
{
size_t accumulator = lastRun - RUN_MASK;
*op++ = RUN_MASK << ML_BITS;
for(; accumulator >= 255 ; accumulator-=255) *op++ = 255;
*op++ = (BYTE) accumulator;
}
else
{
*op++ = (BYTE)(lastRun<<ML_BITS);
}
memcpy(op, anchor, lastRun);
op += lastRun;
}
/* End */
return (int) (((char*)op)-dest);
}
int LZ4_compress_fast_extState(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration)
{
LZ4_resetStream((LZ4_stream_t*)state);
if (acceleration < 1) acceleration = ACCELERATION_DEFAULT;
if (maxOutputSize >= LZ4_compressBound(inputSize))
{
if (inputSize < LZ4_64Klimit)
return LZ4_compress_generic(state, source, dest, inputSize, 0, notLimited, byU16, noDict, noDictIssue, acceleration);
else
return LZ4_compress_generic(state, source, dest, inputSize, 0, notLimited, LZ4_64bits() ? byU32 : byPtr, noDict, noDictIssue, acceleration);
}
else
{
if (inputSize < LZ4_64Klimit)
return LZ4_compress_generic(state, source, dest, inputSize, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue, acceleration);
else
return LZ4_compress_generic(state, source, dest, inputSize, maxOutputSize, limitedOutput, LZ4_64bits() ? byU32 : byPtr, noDict, noDictIssue, acceleration);
}
}
int LZ4_compress_fast(const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration)
{
#if (HEAPMODE)
void* ctxPtr = ALLOCATOR(1, sizeof(LZ4_stream_t)); /* malloc-calloc always properly aligned */
#else
LZ4_stream_t ctx;
void* ctxPtr = &ctx;
#endif
int result = LZ4_compress_fast_extState(ctxPtr, source, dest, inputSize, maxOutputSize, acceleration);
#if (HEAPMODE)
FREEMEM(ctxPtr);
#endif
return result;
}
int LZ4_compress_default(const char* source, char* dest, int inputSize, int maxOutputSize)
{
return LZ4_compress_fast(source, dest, inputSize, maxOutputSize, 1);
}
/* hidden debug function */
/* strangely enough, gcc generates faster code when this function is uncommented, even if unused */
int LZ4_compress_fast_force(const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration)
{
LZ4_stream_t ctx;
LZ4_resetStream(&ctx);
if (inputSize < LZ4_64Klimit)
return LZ4_compress_generic(&ctx, source, dest, inputSize, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue, acceleration);
else
return LZ4_compress_generic(&ctx, source, dest, inputSize, maxOutputSize, limitedOutput, LZ4_64bits() ? byU32 : byPtr, noDict, noDictIssue, acceleration);
}
/********************************
* destSize variant
********************************/
static int LZ4_compress_destSize_generic(
void* const ctx,
const char* const src,
char* const dst,
int* const srcSizePtr,
const int targetDstSize,
const tableType_t tableType)
{
const BYTE* ip = (const BYTE*) src;
const BYTE* base = (const BYTE*) src;
const BYTE* lowLimit = (const BYTE*) src;
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* const oend = op + targetDstSize;
BYTE* const oMaxLit = op + targetDstSize - 2 /* offset */ - 8 /* because 8+MINMATCH==MFLIMIT */ - 1 /* token */;
BYTE* const oMaxMatch = op + targetDstSize - (LASTLITERALS + 1 /* token */);
BYTE* const oMaxSeq = oMaxLit - 1 /* token */;
U32 forwardH;
/* Init conditions */
if (targetDstSize < 1) return 0; /* Impossible to store anything */
if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size, too large (or negative) */
if ((tableType == byU16) && (*srcSizePtr>=LZ4_64Klimit)) return 0; /* Size too large (not within 64K limit) */
if (*srcSizePtr<LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */
/* First Byte */
*srcSizePtr = 0;
LZ4_putPosition(ip, ctx, tableType, base);
ip++; forwardH = LZ4_hashPosition(ip, tableType);
/* Main Loop */
for ( ; ; )
{
const BYTE* match;
BYTE* token;
{
const BYTE* forwardIp = ip;
unsigned step = 1;
unsigned searchMatchNb = 1 << LZ4_skipTrigger;
/* Find a match */
do {
U32 h = forwardH;
ip = forwardIp;
forwardIp += step;
step = (searchMatchNb++ >> LZ4_skipTrigger);
if (unlikely(forwardIp > mflimit))
goto _last_literals;
match = LZ4_getPositionOnHash(h, ctx, tableType, base);
forwardH = LZ4_hashPosition(forwardIp, tableType);
LZ4_putPositionOnHash(ip, h, ctx, tableType, base);
} while ( ((tableType==byU16) ? 0 : (match + MAX_DISTANCE < ip))
|| (LZ4_read32(match) != LZ4_read32(ip)) );
}
/* Catch up */
while ((ip>anchor) && (match > lowLimit) && (unlikely(ip[-1]==match[-1]))) { ip--; match--; }
{
/* Encode Literal length */
unsigned litLength = (unsigned)(ip - anchor);
token = op++;
if (op + ((litLength+240)/255) + litLength > oMaxLit)
{
/* Not enough space for a last match */
op--;
goto _last_literals;
}
if (litLength>=RUN_MASK)
{
unsigned len = litLength - RUN_MASK;
*token=(RUN_MASK<<ML_BITS);
for(; len >= 255 ; len-=255) *op++ = 255;
*op++ = (BYTE)len;
}
else *token = (BYTE)(litLength<<ML_BITS);
/* Copy Literals */
LZ4_wildCopy(op, anchor, op+litLength);
op += litLength;
}
_next_match:
/* Encode Offset */
LZ4_writeLE16(op, (U16)(ip-match)); op+=2;
/* Encode MatchLength */
{
size_t matchLength;
matchLength = LZ4_count(ip+MINMATCH, match+MINMATCH, matchlimit);
if (op + ((matchLength+240)/255) > oMaxMatch)
{
/* Match description too long : reduce it */
matchLength = (15-1) + (oMaxMatch-op) * 255;
}
//printf("offset %5i, matchLength%5i \n", (int)(ip-match), matchLength + MINMATCH);
ip += MINMATCH + matchLength;
if (matchLength>=ML_MASK)
{
*token += ML_MASK;
matchLength -= ML_MASK;
while (matchLength >= 255) { matchLength-=255; *op++ = 255; }
*op++ = (BYTE)matchLength;
}
else *token += (BYTE)(matchLength);
}
anchor = ip;
/* Test end of block */
if (ip > mflimit) break;
if (op > oMaxSeq) break;
/* Fill table */
LZ4_putPosition(ip-2, ctx, tableType, base);
/* Test next position */
match = LZ4_getPosition(ip, ctx, tableType, base);
LZ4_putPosition(ip, ctx, tableType, base);
if ( (match+MAX_DISTANCE>=ip)
&& (LZ4_read32(match)==LZ4_read32(ip)) )
{ token=op++; *token=0; goto _next_match; }
/* Prepare next loop */
forwardH = LZ4_hashPosition(++ip, tableType);
}
_last_literals:
/* Encode Last Literals */
{
size_t lastRunSize = (size_t)(iend - anchor);
if (op + 1 /* token */ + ((lastRunSize+240)/255) /* litLength */ + lastRunSize /* literals */ > oend)
{
/* adapt lastRunSize to fill 'dst' */
lastRunSize = (oend-op) - 1;
lastRunSize -= (lastRunSize+240)/255;
}
ip = anchor + lastRunSize;
if (lastRunSize >= RUN_MASK)
{
size_t accumulator = lastRunSize - RUN_MASK;
*op++ = RUN_MASK << ML_BITS;
for(; accumulator >= 255 ; accumulator-=255) *op++ = 255;
*op++ = (BYTE) accumulator;
}
else
{
*op++ = (BYTE)(lastRunSize<<ML_BITS);
}
memcpy(op, anchor, lastRunSize);
op += lastRunSize;
}
/* End */
*srcSizePtr = (int) (((const char*)ip)-src);
return (int) (((char*)op)-dst);
}
static int LZ4_compress_destSize_extState (void* state, const char* src, char* dst, int* srcSizePtr, int targetDstSize)
{
LZ4_resetStream((LZ4_stream_t*)state);
if (targetDstSize >= LZ4_compressBound(*srcSizePtr)) /* compression success is guaranteed */
{
return LZ4_compress_fast_extState(state, src, dst, *srcSizePtr, targetDstSize, 1);
}
else
{
if (*srcSizePtr < LZ4_64Klimit)
return LZ4_compress_destSize_generic(state, src, dst, srcSizePtr, targetDstSize, byU16);
else
return LZ4_compress_destSize_generic(state, src, dst, srcSizePtr, targetDstSize, LZ4_64bits() ? byU32 : byPtr);
}
}
int LZ4_compress_destSize(const char* src, char* dst, int* srcSizePtr, int targetDstSize)
{
#if (HEAPMODE)
void* ctx = ALLOCATOR(1, sizeof(LZ4_stream_t)); /* malloc-calloc always properly aligned */
#else
LZ4_stream_t ctxBody;
void* ctx = &ctxBody;
#endif
int result = LZ4_compress_destSize_extState(ctx, src, dst, srcSizePtr, targetDstSize);
#if (HEAPMODE)
FREEMEM(ctx);
#endif
return result;
}
/********************************
* Streaming functions
********************************/
LZ4_stream_t* LZ4_createStream(void)
{
LZ4_stream_t* lz4s = (LZ4_stream_t*)ALLOCATOR(8, LZ4_STREAMSIZE_U64);
LZ4_STATIC_ASSERT(LZ4_STREAMSIZE >= sizeof(LZ4_stream_t_internal)); /* A compilation error here means LZ4_STREAMSIZE is not large enough */
LZ4_resetStream(lz4s);
return lz4s;
}
void LZ4_resetStream (LZ4_stream_t* LZ4_stream)
{
MEM_INIT(LZ4_stream, 0, sizeof(LZ4_stream_t));
}
int LZ4_freeStream (LZ4_stream_t* LZ4_stream)
{
FREEMEM(LZ4_stream);
return (0);
}
#define HASH_UNIT sizeof(size_t)
int LZ4_loadDict (LZ4_stream_t* LZ4_dict, const char* dictionary, int dictSize)
{
LZ4_stream_t_internal* dict = (LZ4_stream_t_internal*) LZ4_dict;
const BYTE* p = (const BYTE*)dictionary;
const BYTE* const dictEnd = p + dictSize;
const BYTE* base;
if ((dict->initCheck) || (dict->currentOffset > 1 GB)) /* Uninitialized structure, or reuse overflow */
LZ4_resetStream(LZ4_dict);
if (dictSize < (int)HASH_UNIT)
{
dict->dictionary = NULL;
dict->dictSize = 0;
return 0;
}
if ((dictEnd - p) > 64 KB) p = dictEnd - 64 KB;
dict->currentOffset += 64 KB;
base = p - dict->currentOffset;
dict->dictionary = p;
dict->dictSize = (U32)(dictEnd - p);
dict->currentOffset += dict->dictSize;
while (p <= dictEnd-HASH_UNIT)
{
LZ4_putPosition(p, dict->hashTable, byU32, base);
p+=3;
}
return dict->dictSize;
}
static void LZ4_renormDictT(LZ4_stream_t_internal* LZ4_dict, const BYTE* src)
{
if ((LZ4_dict->currentOffset > 0x80000000) ||
((size_t)LZ4_dict->currentOffset > (size_t)src)) /* address space overflow */
{
/* rescale hash table */
U32 delta = LZ4_dict->currentOffset - 64 KB;
const BYTE* dictEnd = LZ4_dict->dictionary + LZ4_dict->dictSize;
int i;
for (i=0; i<HASH_SIZE_U32; i++)
{