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/*
LZ4 - Fast LZ compression algorithm
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Copyright ( C ) 2011 - present , Yann Collet .
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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 : //www.lz4.org
- LZ4 source repository : https : //github.com/lz4/lz4
*/
/*-************************************
* Tuning parameters
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*
* LZ4_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 ( ) ) .
*/
# ifndef LZ4_HEAPMODE
# define LZ4_HEAPMODE 0
# endif
/*
* ACCELERATION_DEFAULT :
* Select " acceleration " for LZ4_compress_fast ( ) when parameter value < = 0
*/
# define ACCELERATION_DEFAULT 1
/*-************************************
* CPU Feature Detection
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* LZ4_FORCE_MEMORY_ACCESS
* By default , access to unaligned memory is controlled by ` memcpy ( ) ` , which is safe and portable .
* Unfortunately , on some target / compiler combinations , the generated assembly is sub - optimal .
* The below switch allow to select different access method for improved performance .
* Method 0 ( default ) : use ` memcpy ( ) ` . Safe and portable .
* Method 1 : ` __packed ` statement . It depends on compiler extension ( ie , not portable ) .
* This method is safe if your compiler supports it , and * generally * as fast or faster than ` memcpy ` .
* Method 2 : direct access . This method is portable but violate C standard .
* It can generate buggy code on targets which assembly generation depends on alignment .
* But in some circumstances , it ' s the only known way to get the most performance ( ie GCC + ARMv6 )
* See https : //fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
* Prefer these methods in priority order ( 0 > 1 > 2 )
*/
# ifndef LZ4_FORCE_MEMORY_ACCESS /* can be defined externally */
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# if defined(__GNUC__) && \
( defined ( __ARM_ARCH_6__ ) | | defined ( __ARM_ARCH_6J__ ) | | defined ( __ARM_ARCH_6K__ ) \
| | defined ( __ARM_ARCH_6Z__ ) | | defined ( __ARM_ARCH_6ZK__ ) | | defined ( __ARM_ARCH_6T2__ ) )
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# define LZ4_FORCE_MEMORY_ACCESS 2
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# elif (defined(__INTEL_COMPILER) && !defined(_WIN32)) || defined(__GNUC__)
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# define LZ4_FORCE_MEMORY_ACCESS 1
# endif
# endif
/*
* LZ4_FORCE_SW_BITCOUNT
* Define this parameter if your target system or compiler does not support hardware bit count
*/
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# if defined(_MSC_VER) && defined(_WIN32_WCE) /* Visual Studio for WinCE doesn't support Hardware bit count */
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# define LZ4_FORCE_SW_BITCOUNT
# endif
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/*-************************************
* Dependency
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
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/*
* LZ4_SRC_INCLUDED :
* Amalgamation flag , whether lz4 . c is included
*/
# ifndef LZ4_SRC_INCLUDED
# define LZ4_SRC_INCLUDED 1
# endif
# ifndef LZ4_STATIC_LINKING_ONLY
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# define LZ4_STATIC_LINKING_ONLY
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# endif
# ifndef LZ4_DISABLE_DEPRECATE_WARNINGS
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# define LZ4_DISABLE_DEPRECATE_WARNINGS /* due to LZ4_decompress_safe_withPrefix64k */
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# endif
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# include "tracy_lz4.hpp"
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/* see also "memory routines" below */
/*-************************************
* Compiler Options
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
# ifdef _MSC_VER /* Visual Studio */
# include <intrin.h>
# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
# pragma warning(disable : 4293) /* disable: C4293: too large shift (32-bits) */
# endif /* _MSC_VER */
# ifndef LZ4_FORCE_INLINE
# ifdef _MSC_VER /* Visual Studio */
# define LZ4_FORCE_INLINE static __forceinline
# else
# if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */
# ifdef __GNUC__
# define LZ4_FORCE_INLINE static inline __attribute__((always_inline))
# else
# define LZ4_FORCE_INLINE static inline
# endif
# else
# define LZ4_FORCE_INLINE static
# endif /* __STDC_VERSION__ */
# endif /* _MSC_VER */
# endif /* LZ4_FORCE_INLINE */
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/* LZ4_FORCE_O2_GCC_PPC64LE and LZ4_FORCE_O2_INLINE_GCC_PPC64LE
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* gcc on ppc64le generates an unrolled SIMDized loop for LZ4_wildCopy8 ,
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* together with a simple 8 - byte copy loop as a fall - back path .
* However , this optimization hurts the decompression speed by > 30 % ,
* because the execution does not go to the optimized loop
* for typical compressible data , and all of the preamble checks
* before going to the fall - back path become useless overhead .
* This optimization happens only with the - O3 flag , and - O2 generates
* a simple 8 - byte copy loop .
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* With gcc on ppc64le , all of the LZ4_decompress_ * and LZ4_wildCopy8
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* functions are annotated with __attribute__ ( ( optimize ( " O2 " ) ) ) ,
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* and also LZ4_wildCopy8 is forcibly inlined , so that the O2 attribute
* of LZ4_wildCopy8 does not affect the compression speed .
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*/
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# if defined(__PPC64__) && defined(__LITTLE_ENDIAN__) && defined(__GNUC__) && !defined(__clang__)
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# define LZ4_FORCE_O2_GCC_PPC64LE __attribute__((optimize("O2")))
# define LZ4_FORCE_O2_INLINE_GCC_PPC64LE __attribute__((optimize("O2"))) LZ4_FORCE_INLINE
# else
# define LZ4_FORCE_O2_GCC_PPC64LE
# define LZ4_FORCE_O2_INLINE_GCC_PPC64LE static
# endif
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# if (defined(__GNUC__) && (__GNUC__ >= 3)) || (defined(__INTEL_COMPILER) && (__INTEL_COMPILER >= 800)) || defined(__clang__)
# define expect(expr,value) (__builtin_expect ((expr),(value)) )
# else
# define expect(expr,value) (expr)
# endif
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# ifndef likely
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# define likely(expr) expect((expr) != 0, 1)
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# endif
# ifndef unlikely
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# define unlikely(expr) expect((expr) != 0, 0)
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# endif
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/*-************************************
* Memory routines
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
# include <stdlib.h> /* malloc, calloc, free */
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# define ALLOC(s) malloc(s)
# define ALLOC_AND_ZERO(s) calloc(1,s)
# define FREEMEM(p) free(p)
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# include <string.h> /* memset, memcpy */
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# define MEM_INIT(p,v,s) memset((p),(v),(s))
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/*-************************************
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* Types
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* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
# if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */ )
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# include <stdint.h>
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typedef uint8_t BYTE ;
typedef uint16_t U16 ;
typedef uint32_t U32 ;
typedef int32_t S32 ;
typedef uint64_t U64 ;
typedef uintptr_t uptrval ;
# else
typedef unsigned char BYTE ;
typedef unsigned short U16 ;
typedef unsigned int U32 ;
typedef signed int S32 ;
typedef unsigned long long U64 ;
typedef size_t uptrval ; /* generally true, except OpenVMS-64 */
# endif
# if defined(__x86_64__)
typedef U64 reg_t ; /* 64-bits in x32 mode */
# else
typedef size_t reg_t ; /* 32-bits in x32 mode */
# endif
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namespace tracy
{
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typedef enum {
notLimited = 0 ,
limitedOutput = 1 ,
fillOutput = 2
} limitedOutput_directive ;
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/*-************************************
* Reading and writing into memory
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
static unsigned LZ4_isLittleEndian ( void )
{
const union { U32 u ; BYTE c [ 4 ] ; } one = { 1 } ; /* don't use static : performance detrimental */
return one . c [ 0 ] ;
}
# if defined(LZ4_FORCE_MEMORY_ACCESS) && (LZ4_FORCE_MEMORY_ACCESS==2)
/* lie to the compiler about data alignment; use with caution */
static U16 LZ4_read16 ( const void * memPtr ) { return * ( const U16 * ) memPtr ; }
static U32 LZ4_read32 ( const void * memPtr ) { return * ( const U32 * ) memPtr ; }
static reg_t LZ4_read_ARCH ( const void * memPtr ) { return * ( const reg_t * ) memPtr ; }
static void LZ4_write16 ( void * memPtr , U16 value ) { * ( U16 * ) memPtr = value ; }
static void LZ4_write32 ( void * memPtr , U32 value ) { * ( U32 * ) memPtr = value ; }
# elif defined(LZ4_FORCE_MEMORY_ACCESS) && (LZ4_FORCE_MEMORY_ACCESS==1)
/* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
/* currently only defined for gcc and icc */
typedef union { U16 u16 ; U32 u32 ; reg_t uArch ; } __attribute__ ( ( packed ) ) unalign ;
static U16 LZ4_read16 ( const void * ptr ) { return ( ( const unalign * ) ptr ) - > u16 ; }
static U32 LZ4_read32 ( const void * ptr ) { return ( ( const unalign * ) ptr ) - > u32 ; }
static reg_t LZ4_read_ARCH ( const void * ptr ) { return ( ( const unalign * ) ptr ) - > uArch ; }
static void LZ4_write16 ( void * memPtr , U16 value ) { ( ( unalign * ) memPtr ) - > u16 = value ; }
static void LZ4_write32 ( void * memPtr , U32 value ) { ( ( unalign * ) memPtr ) - > u32 = value ; }
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# else /* safe and portable access using memcpy() */
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static U16 LZ4_read16 ( const void * memPtr )
{
U16 val ; memcpy ( & val , memPtr , sizeof ( val ) ) ; return val ;
}
static U32 LZ4_read32 ( const void * memPtr )
{
U32 val ; memcpy ( & val , memPtr , sizeof ( val ) ) ; return val ;
}
static reg_t LZ4_read_ARCH ( const void * memPtr )
{
reg_t val ; memcpy ( & val , memPtr , sizeof ( val ) ) ; return val ;
}
static void LZ4_write16 ( void * memPtr , U16 value )
{
memcpy ( memPtr , & value , sizeof ( value ) ) ;
}
static void LZ4_write32 ( void * memPtr , U32 value )
{
memcpy ( memPtr , & value , sizeof ( value ) ) ;
}
# endif /* LZ4_FORCE_MEMORY_ACCESS */
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 ( ) ) {
LZ4_write16 ( memPtr , value ) ;
} else {
BYTE * p = ( BYTE * ) memPtr ;
p [ 0 ] = ( BYTE ) value ;
p [ 1 ] = ( BYTE ) ( value > > 8 ) ;
}
}
/* customized variant of memcpy, which can overwrite up to 8 bytes beyond dstEnd */
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LZ4_FORCE_O2_INLINE_GCC_PPC64LE
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void LZ4_wildCopy8 ( void * dstPtr , const void * srcPtr , void * dstEnd )
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{
BYTE * d = ( BYTE * ) dstPtr ;
const BYTE * s = ( const BYTE * ) srcPtr ;
BYTE * const e = ( BYTE * ) dstEnd ;
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do { memcpy ( d , s , 8 ) ; d + = 8 ; s + = 8 ; } while ( d < e ) ;
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}
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static const unsigned inc32table [ 8 ] = { 0 , 1 , 2 , 1 , 0 , 4 , 4 , 4 } ;
static const int dec64table [ 8 ] = { 0 , 0 , 0 , - 1 , - 4 , 1 , 2 , 3 } ;
# ifndef LZ4_FAST_DEC_LOOP
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# if defined __i386 || defined _M_IX86 || defined __x86_64__ || defined _M_X64
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# define LZ4_FAST_DEC_LOOP 1
# else
# define LZ4_FAST_DEC_LOOP 0
# endif
# endif
# if LZ4_FAST_DEC_LOOP
LZ4_FORCE_O2_INLINE_GCC_PPC64LE void
LZ4_memcpy_using_offset_base ( BYTE * dstPtr , const BYTE * srcPtr , BYTE * dstEnd , const size_t offset )
{
if ( offset < 8 ) {
dstPtr [ 0 ] = srcPtr [ 0 ] ;
dstPtr [ 1 ] = srcPtr [ 1 ] ;
dstPtr [ 2 ] = srcPtr [ 2 ] ;
dstPtr [ 3 ] = srcPtr [ 3 ] ;
srcPtr + = inc32table [ offset ] ;
memcpy ( dstPtr + 4 , srcPtr , 4 ) ;
srcPtr - = dec64table [ offset ] ;
dstPtr + = 8 ;
} else {
memcpy ( dstPtr , srcPtr , 8 ) ;
dstPtr + = 8 ;
srcPtr + = 8 ;
}
LZ4_wildCopy8 ( dstPtr , srcPtr , dstEnd ) ;
}
/* customized variant of memcpy, which can overwrite up to 32 bytes beyond dstEnd
* this version copies two times 16 bytes ( instead of one time 32 bytes )
* because it must be compatible with offsets > = 16. */
LZ4_FORCE_O2_INLINE_GCC_PPC64LE void
LZ4_wildCopy32 ( void * dstPtr , const void * srcPtr , void * dstEnd )
{
BYTE * d = ( BYTE * ) dstPtr ;
const BYTE * s = ( const BYTE * ) srcPtr ;
BYTE * const e = ( BYTE * ) dstEnd ;
do { memcpy ( d , s , 16 ) ; memcpy ( d + 16 , s + 16 , 16 ) ; d + = 32 ; s + = 32 ; } while ( d < e ) ;
}
LZ4_FORCE_O2_INLINE_GCC_PPC64LE void
LZ4_memcpy_using_offset ( BYTE * dstPtr , const BYTE * srcPtr , BYTE * dstEnd , const size_t offset )
{
BYTE v [ 8 ] ;
switch ( offset ) {
case 1 :
memset ( v , * srcPtr , 8 ) ;
goto copy_loop ;
case 2 :
memcpy ( v , srcPtr , 2 ) ;
memcpy ( & v [ 2 ] , srcPtr , 2 ) ;
memcpy ( & v [ 4 ] , & v [ 0 ] , 4 ) ;
goto copy_loop ;
case 4 :
memcpy ( v , srcPtr , 4 ) ;
memcpy ( & v [ 4 ] , srcPtr , 4 ) ;
goto copy_loop ;
default :
LZ4_memcpy_using_offset_base ( dstPtr , srcPtr , dstEnd , offset ) ;
return ;
}
copy_loop :
memcpy ( dstPtr , v , 8 ) ;
dstPtr + = 8 ;
while ( dstPtr < dstEnd ) {
memcpy ( dstPtr , v , 8 ) ;
dstPtr + = 8 ;
}
}
# endif
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/*-************************************
* Common Constants
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
# define MINMATCH 4
# define WILDCOPYLENGTH 8
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# define LASTLITERALS 5 /* see ../doc/lz4_Block_format.md#parsing-restrictions */
# define MFLIMIT 12 /* see ../doc/lz4_Block_format.md#parsing-restrictions */
# define MATCH_SAFEGUARD_DISTANCE ((2*WILDCOPYLENGTH) - MINMATCH) /* ensure it's possible to write 2 x wildcopyLength without overflowing output buffer */
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# define FASTLOOP_SAFE_DISTANCE 64
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static const int LZ4_minLength = ( MFLIMIT + 1 ) ;
# define KB *(1 <<10)
# define MB *(1 <<20)
# define GB *(1U<<30)
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# ifndef LZ4_DISTANCE_MAX /* can be user - defined at compile time */
# define LZ4_DISTANCE_MAX 65535
# endif
# if (LZ4_DISTANCE_MAX > 65535) /* max supported by LZ4 format */
# error "LZ4_DISTANCE_MAX is too big : must be <= 65535"
# endif
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# define ML_BITS 4
# define ML_MASK ((1U<<ML_BITS)-1)
# define RUN_BITS (8-ML_BITS)
# define RUN_MASK ((1U<<RUN_BITS)-1)
/*-************************************
* Error detection
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
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# if defined(LZ4_DEBUG) && (LZ4_DEBUG>=1)
# include <assert.h>
# else
# ifndef assert
# define assert(condition) ((void)0)
# endif
# endif
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# define LZ4_STATIC_ASSERT(c) { enum { LZ4_static_assert = 1 / (int)(!!(c)) }; } /* use after variable declarations */
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# if defined(LZ4_DEBUG) && (LZ4_DEBUG>=2)
# include <stdio.h>
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static int g_debuglog_enable = 1 ;
# define DEBUGLOG(l, ...) { \
if ( ( g_debuglog_enable ) & & ( l < = LZ4_DEBUG ) ) { \
fprintf ( stderr , __FILE__ " : " ) ; \
fprintf ( stderr , __VA_ARGS__ ) ; \
fprintf ( stderr , " \n " ) ; \
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} }
# else
# define DEBUGLOG(l, ...) {} /* disabled */
# endif
/*-************************************
* Common functions
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
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static unsigned LZ4_NbCommonBytes ( reg_t val )
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{
if ( LZ4_isLittleEndian ( ) ) {
if ( sizeof ( val ) = = 8 ) {
# 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__) || (defined(__GNUC__) && (__GNUC__>=3))) && !defined(LZ4_FORCE_SW_BITCOUNT)
return ( __builtin_ctzll ( ( U64 ) val ) > > 3 ) ;
# else
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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 } ;
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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__) || (defined(__GNUC__) && (__GNUC__>=3))) && !defined(LZ4_FORCE_SW_BITCOUNT)
return ( __builtin_ctz ( ( U32 ) val ) > > 3 ) ;
# else
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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 } ;
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return DeBruijnBytePos [ ( ( U32 ) ( ( val & - ( S32 ) val ) * 0x077CB531U ) ) > > 27 ] ;
# endif
}
} else /* Big Endian CPU */ {
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if ( sizeof ( val ) = = 8 ) { /* 64-bits */
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# 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__) || (defined(__GNUC__) && (__GNUC__>=3))) && !defined(LZ4_FORCE_SW_BITCOUNT)
return ( __builtin_clzll ( ( U64 ) val ) > > 3 ) ;
# else
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static const U32 by32 = sizeof ( val ) * 4 ; /* 32 on 64 bits (goal), 16 on 32 bits.
Just to avoid some static analyzer complaining about shift by 32 on 32 - bits target .
Note that this code path is never triggered in 32 - bits mode . */
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unsigned r ;
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if ( ! ( val > > by32 ) ) { r = 4 ; } else { r = 0 ; val > > = by32 ; }
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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__) || (defined(__GNUC__) && (__GNUC__>=3))) && !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
}
}
}
# define STEPSIZE sizeof(reg_t)
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LZ4_FORCE_INLINE
unsigned LZ4_count ( const BYTE * pIn , const BYTE * pMatch , const BYTE * pInLimit )
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{
const BYTE * const pStart = pIn ;
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if ( likely ( pIn < pInLimit - ( STEPSIZE - 1 ) ) ) {
reg_t const diff = LZ4_read_ARCH ( pMatch ) ^ LZ4_read_ARCH ( pIn ) ;
if ( ! diff ) {
pIn + = STEPSIZE ; pMatch + = STEPSIZE ;
} else {
return LZ4_NbCommonBytes ( diff ) ;
} }
while ( likely ( pIn < pInLimit - ( STEPSIZE - 1 ) ) ) {
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reg_t const 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 ( ( STEPSIZE = = 8 ) & & ( 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
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
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
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
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typedef enum { clearedTable = 0 , byPtr , byU32 , byU16 } tableType_t ;
/**
* This enum distinguishes several different modes of accessing previous
* content in the stream .
*
* - noDict : There is no preceding content .
* - withPrefix64k : Table entries up to ctx - > dictSize before the current blob
* blob being compressed are valid and refer to the preceding
* content ( of length ctx - > dictSize ) , which is available
* contiguously preceding in memory the content currently
* being compressed .
* - usingExtDict : Like withPrefix64k , but the preceding content is somewhere
* else in memory , starting at ctx - > dictionary with length
* ctx - > dictSize .
* - usingDictCtx : Like usingExtDict , but everything concerning the preceding
* content is in a separate context , pointed to by
* ctx - > dictCtx . ctx - > dictionary , ctx - > dictSize , and table
* entries in the current context that refer to positions
* preceding the beginning of the current compression are
* ignored . Instead , ctx - > dictCtx - > dictionary and ctx - > dictCtx
* - > dictSize describe the location and size of the preceding
* content , and matches are found by looking in the ctx
* - > dictCtx - > hashTable .
*/
typedef enum { noDict = 0 , withPrefix64k , usingExtDict , usingDictCtx } dict_directive ;
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typedef enum { noDictIssue = 0 , dictSmall } dictIssue_directive ;
/*-************************************
* Local Utils
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
int LZ4_versionNumber ( void ) { return LZ4_VERSION_NUMBER ; }
const char * LZ4_versionString ( void ) { return LZ4_VERSION_STRING ; }
int LZ4_compressBound ( int isize ) { return LZ4_COMPRESSBOUND ( isize ) ; }
int LZ4_sizeofState ( ) { return LZ4_STREAMSIZE ; }
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/*-************************************
* Internal Definitions used in Tests
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
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int LZ4_compress_forceExtDict ( LZ4_stream_t * LZ4_stream , const char * source , char * dest , int inputSize ) ;
int LZ4_decompress_safe_forceExtDict ( const char * in , char * out , int inSize , int outSize , const void * dict , size_t dictSize ) ;
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/*-******************************
* Compression functions
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
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LZ4_FORCE_INLINE U32 LZ4_hash4 ( U32 sequence , tableType_t const tableType )
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{
if ( tableType = = byU16 )
return ( ( sequence * 2654435761U ) > > ( ( MINMATCH * 8 ) - ( LZ4_HASHLOG + 1 ) ) ) ;
else
return ( ( sequence * 2654435761U ) > > ( ( MINMATCH * 8 ) - LZ4_HASHLOG ) ) ;
}
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LZ4_FORCE_INLINE U32 LZ4_hash5 ( U64 sequence , tableType_t const tableType )
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{
const U32 hashLog = ( tableType = = byU16 ) ? LZ4_HASHLOG + 1 : LZ4_HASHLOG ;
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if ( LZ4_isLittleEndian ( ) ) {
const U64 prime5bytes = 889523592379ULL ;
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return ( U32 ) ( ( ( sequence < < 24 ) * prime5bytes ) > > ( 64 - hashLog ) ) ;
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} else {
const U64 prime8bytes = 11400714785074694791ULL ;
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return ( U32 ) ( ( ( sequence > > 24 ) * prime8bytes ) > > ( 64 - hashLog ) ) ;
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}
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}
LZ4_FORCE_INLINE U32 LZ4_hashPosition ( const void * const p , tableType_t const tableType )
{
if ( ( sizeof ( reg_t ) = = 8 ) & & ( tableType ! = byU16 ) ) return LZ4_hash5 ( LZ4_read_ARCH ( p ) , tableType ) ;
return LZ4_hash4 ( LZ4_read32 ( p ) , tableType ) ;
}
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LZ4_FORCE_INLINE void LZ4_putIndexOnHash ( U32 idx , U32 h , void * tableBase , tableType_t const tableType )
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{
switch ( tableType )
{
default : /* fallthrough */
case clearedTable : /* fallthrough */
case byPtr : { /* illegal! */ assert ( 0 ) ; return ; }
case byU32 : { U32 * hashTable = ( U32 * ) tableBase ; hashTable [ h ] = idx ; return ; }
case byU16 : { U16 * hashTable = ( U16 * ) tableBase ; assert ( idx < 65536 ) ; hashTable [ h ] = ( U16 ) idx ; return ; }
}
}
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LZ4_FORCE_INLINE void LZ4_putPositionOnHash ( const BYTE * p , U32 h ,
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void * tableBase , tableType_t const tableType ,
const BYTE * srcBase )
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{
switch ( tableType )
{
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case clearedTable : { /* illegal! */ assert ( 0 ) ; return ; }
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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 ; }
}
}
LZ4_FORCE_INLINE void LZ4_putPosition ( const BYTE * p , void * tableBase , tableType_t tableType , const BYTE * srcBase )
{
U32 const h = LZ4_hashPosition ( p , tableType ) ;
LZ4_putPositionOnHash ( p , h , tableBase , tableType , srcBase ) ;
}
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/* LZ4_getIndexOnHash() :
* Index of match position registered in hash table .
* hash position must be calculated by using base + index , or dictBase + index .
* Assumption 1 : only valid if tableType = = byU32 or byU16 .
* Assumption 2 : h is presumed valid ( within limits of hash table )
*/
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LZ4_FORCE_INLINE U32 LZ4_getIndexOnHash ( U32 h , const void * tableBase , tableType_t tableType )
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{
LZ4_STATIC_ASSERT ( LZ4_MEMORY_USAGE > 2 ) ;
if ( tableType = = byU32 ) {
const U32 * const hashTable = ( const U32 * ) tableBase ;
assert ( h < ( 1U < < ( LZ4_MEMORY_USAGE - 2 ) ) ) ;
return hashTable [ h ] ;
}
if ( tableType = = byU16 ) {
const U16 * const hashTable = ( const U16 * ) tableBase ;
assert ( h < ( 1U < < ( LZ4_MEMORY_USAGE - 1 ) ) ) ;
return hashTable [ h ] ;
}
assert ( 0 ) ; return 0 ; /* forbidden case */
}
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LZ4_FORCE_INLINE const BYTE * LZ4_getPositionOnHash ( U32 h , const void * tableBase , tableType_t tableType , const BYTE * srcBase )
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{
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if ( tableType = = byPtr ) { const BYTE * const * hashTable = ( const BYTE * const * ) tableBase ; return hashTable [ h ] ; }
if ( tableType = = byU32 ) { const U32 * const hashTable = ( const U32 * ) tableBase ; return hashTable [ h ] + srcBase ; }
{ const U16 * const hashTable = ( const U16 * ) tableBase ; return hashTable [ h ] + srcBase ; } /* default, to ensure a return */
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}
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LZ4_FORCE_INLINE const BYTE * LZ4_getPosition ( const BYTE * p ,
const void * tableBase , tableType_t tableType ,
const BYTE * srcBase )
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{
U32 const h = LZ4_hashPosition ( p , tableType ) ;
return LZ4_getPositionOnHash ( h , tableBase , tableType , srcBase ) ;
}
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LZ4_FORCE_INLINE void LZ4_prepareTable (
LZ4_stream_t_internal * const cctx ,
const int inputSize ,
const tableType_t tableType ) {
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/* If compression failed during the previous step, then the context
* is marked as dirty , therefore , it has to be fully reset .
*/
if ( cctx - > dirty ) {
DEBUGLOG ( 5 , " LZ4_prepareTable: Full reset for %p " , cctx ) ;
MEM_INIT ( cctx , 0 , sizeof ( LZ4_stream_t_internal ) ) ;
return ;
}
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/* If the table hasn't been used, it's guaranteed to be zeroed out, and is
* therefore safe to use no matter what mode we ' re in . Otherwise , we figure
* out if it ' s safe to leave as is or whether it needs to be reset .
*/
if ( cctx - > tableType ! = clearedTable ) {
if ( cctx - > tableType ! = tableType
| | ( tableType = = byU16 & & cctx - > currentOffset + inputSize > = 0xFFFFU )
| | ( tableType = = byU32 & & cctx - > currentOffset > 1 GB )
| | tableType = = byPtr
| | inputSize > = 4 KB )
{
DEBUGLOG ( 4 , " LZ4_prepareTable: Resetting table in %p " , cctx ) ;
MEM_INIT ( cctx - > hashTable , 0 , LZ4_HASHTABLESIZE ) ;
cctx - > currentOffset = 0 ;
cctx - > tableType = clearedTable ;
} else {
DEBUGLOG ( 4 , " LZ4_prepareTable: Re-use hash table (no reset) " ) ;
}
}
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/* Adding a gap, so all previous entries are > LZ4_DISTANCE_MAX back, is faster
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* than compressing without a gap . However , compressing with
* currentOffset = = 0 is faster still , so we preserve that case .
*/
if ( cctx - > currentOffset ! = 0 & & tableType = = byU32 ) {
DEBUGLOG ( 5 , " LZ4_prepareTable: adding 64KB to currentOffset " ) ;
cctx - > currentOffset + = 64 KB ;
}
/* Finally, clear history */
cctx - > dictCtx = NULL ;
cctx - > dictionary = NULL ;
cctx - > dictSize = 0 ;
}
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/** LZ4_compress_generic() :
inlined , to ensure branches are decided at compilation time */
LZ4_FORCE_INLINE int LZ4_compress_generic (
LZ4_stream_t_internal * const cctx ,
const char * const source ,
char * const dest ,
const int inputSize ,
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int * inputConsumed , /* only written when outputDirective == fillOutput */
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const int maxOutputSize ,
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const limitedOutput_directive outputDirective ,
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const tableType_t tableType ,
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const dict_directive dictDirective ,
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const dictIssue_directive dictIssue ,
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const int acceleration )
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{
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int result ;
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const BYTE * ip = ( const BYTE * ) source ;
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U32 const startIndex = cctx - > currentOffset ;
const BYTE * base = ( const BYTE * ) source - startIndex ;
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const BYTE * lowLimit ;
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const LZ4_stream_t_internal * dictCtx = ( const LZ4_stream_t_internal * ) cctx - > dictCtx ;
const BYTE * const dictionary =
dictDirective = = usingDictCtx ? dictCtx - > dictionary : cctx - > dictionary ;
const U32 dictSize =
dictDirective = = usingDictCtx ? dictCtx - > dictSize : cctx - > dictSize ;
const U32 dictDelta = ( dictDirective = = usingDictCtx ) ? startIndex - dictCtx - > currentOffset : 0 ; /* make indexes in dictCtx comparable with index in current context */
int const maybe_extMem = ( dictDirective = = usingExtDict ) | | ( dictDirective = = usingDictCtx ) ;
U32 const prefixIdxLimit = startIndex - dictSize ; /* used when dictDirective == dictSmall */
const BYTE * const dictEnd = dictionary + dictSize ;
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const BYTE * anchor = ( const BYTE * ) source ;
const BYTE * const iend = ip + inputSize ;
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const BYTE * const mflimitPlusOne = iend - MFLIMIT + 1 ;
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const BYTE * const matchlimit = iend - LASTLITERALS ;
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/* the dictCtx currentOffset is indexed on the start of the dictionary,
* while a dictionary in the current context precedes the currentOffset */
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const BYTE * dictBase = ( dictDirective = = usingDictCtx ) ?
dictionary + dictSize - dictCtx - > currentOffset :
dictionary + dictSize - startIndex ;
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BYTE * op = ( BYTE * ) dest ;
BYTE * const olimit = op + maxOutputSize ;
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U32 offset = 0 ;
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U32 forwardH ;
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DEBUGLOG ( 5 , " LZ4_compress_generic: srcSize=%i, tableType=%u " , inputSize , tableType ) ;
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/* If init conditions are not met, we don't have to mark stream
* as having dirty context , since no action was taken yet */
if ( outputDirective = = fillOutput & & maxOutputSize < 1 ) return 0 ; /* Impossible to store anything */
if ( ( U32 ) inputSize > ( U32 ) LZ4_MAX_INPUT_SIZE ) return 0 ; /* Unsupported inputSize, too large (or negative) */
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if ( ( tableType = = byU16 ) & & ( inputSize > = LZ4_64Klimit ) ) return 0 ; /* Size too large (not within 64K limit) */
if ( tableType = = byPtr ) assert ( dictDirective = = noDict ) ; /* only supported use case with byPtr */
assert ( acceleration > = 1 ) ;
lowLimit = ( const BYTE * ) source - ( dictDirective = = withPrefix64k ? dictSize : 0 ) ;
/* Update context state */
if ( dictDirective = = usingDictCtx ) {
/* Subsequent linked blocks can't use the dictionary. */
/* Instead, they use the block we just compressed. */
cctx - > dictCtx = NULL ;
cctx - > dictSize = ( U32 ) inputSize ;
} else {
cctx - > dictSize + = ( U32 ) inputSize ;
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}
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cctx - > currentOffset + = ( U32 ) inputSize ;
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cctx - > tableType = ( U16 ) tableType ;
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if ( inputSize < LZ4_minLength ) goto _last_literals ; /* Input too small, no compression (all literals) */
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/* First Byte */
LZ4_putPosition ( ip , cctx - > hashTable , tableType , base ) ;
ip + + ; forwardH = LZ4_hashPosition ( ip , tableType ) ;
/* Main Loop */
for ( ; ; ) {
const BYTE * match ;
BYTE * token ;
/* Find a match */
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if ( tableType = = byPtr ) {
const BYTE * forwardIp = ip ;
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int step = 1 ;
int searchMatchNb = acceleration < < LZ4_skipTrigger ;
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do {
U32 const h = forwardH ;
ip = forwardIp ;
forwardIp + = step ;
step = ( searchMatchNb + + > > LZ4_skipTrigger ) ;
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if ( unlikely ( forwardIp > mflimitPlusOne ) ) goto _last_literals ;
assert ( ip < mflimitPlusOne ) ;
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match = LZ4_getPositionOnHash ( h , cctx - > hashTable , tableType , base ) ;
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forwardH = LZ4_hashPosition ( forwardIp , tableType ) ;
LZ4_putPositionOnHash ( ip , h , cctx - > hashTable , tableType , base ) ;
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} while ( ( match + LZ4_DISTANCE_MAX < ip )
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| | ( LZ4_read32 ( match ) ! = LZ4_read32 ( ip ) ) ) ;
} else { /* byU32, byU16 */
const BYTE * forwardIp = ip ;
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int step = 1 ;
int searchMatchNb = acceleration < < LZ4_skipTrigger ;
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do {
U32 const h = forwardH ;
U32 const current = ( U32 ) ( forwardIp - base ) ;
U32 matchIndex = LZ4_getIndexOnHash ( h , cctx - > hashTable , tableType ) ;
assert ( matchIndex < = current ) ;
assert ( forwardIp - base < ( ptrdiff_t ) ( 2 GB - 1 ) ) ;
ip = forwardIp ;
forwardIp + = step ;
step = ( searchMatchNb + + > > LZ4_skipTrigger ) ;
if ( unlikely ( forwardIp > mflimitPlusOne ) ) goto _last_literals ;
assert ( ip < mflimitPlusOne ) ;
if ( dictDirective = = usingDictCtx ) {
if ( matchIndex < startIndex ) {
/* there was no match, try the dictionary */
assert ( tableType = = byU32 ) ;
matchIndex = LZ4_getIndexOnHash ( h , dictCtx - > hashTable , byU32 ) ;
match = dictBase + matchIndex ;
matchIndex + = dictDelta ; /* make dictCtx index comparable with current context */
lowLimit = dictionary ;
} else {
match = base + matchIndex ;
lowLimit = ( const BYTE * ) source ;
}
} else if ( dictDirective = = usingExtDict ) {
if ( matchIndex < startIndex ) {
DEBUGLOG ( 7 , " extDict candidate: matchIndex=%5u < startIndex=%5u " , matchIndex , startIndex ) ;
assert ( startIndex - matchIndex > = MINMATCH ) ;
match = dictBase + matchIndex ;
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lowLimit = dictionary ;
} else {
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match = base + matchIndex ;
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lowLimit = ( const BYTE * ) source ;
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}
} else { /* single continuous memory segment */
match = base + matchIndex ;
}
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forwardH = LZ4_hashPosition ( forwardIp , tableType ) ;
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LZ4_putIndexOnHash ( current , h , cctx - > hashTable , tableType ) ;
if ( ( dictIssue = = dictSmall ) & & ( matchIndex < prefixIdxLimit ) ) continue ; /* match outside of valid area */
assert ( matchIndex < current ) ;
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if ( ( tableType ! = byU16 ) & & ( matchIndex + LZ4_DISTANCE_MAX < current ) ) continue ; /* too far */
if ( tableType = = byU16 ) assert ( ( current - matchIndex ) < = LZ4_DISTANCE_MAX ) ; /* too_far presumed impossible with byU16 */
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if ( LZ4_read32 ( match ) = = LZ4_read32 ( ip ) ) {
if ( maybe_extMem ) offset = current - matchIndex ;
break ; /* match found */
}
} while ( 1 ) ;
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}
/* Catch up */
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while ( ( ( ip > anchor ) & ( match > lowLimit ) ) & & ( unlikely ( ip [ - 1 ] = = match [ - 1 ] ) ) ) { ip - - ; match - - ; }
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/* Encode Literals */
{ unsigned const litLength = ( unsigned ) ( ip - anchor ) ;
token = op + + ;
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if ( ( outputDirective = = limitedOutput ) & & /* Check output buffer overflow */
( unlikely ( op + litLength + ( 2 + 1 + LASTLITERALS ) + ( litLength / 255 ) > olimit ) ) )
return 0 ; /* cannot compress within `dst` budget. Stored indexes in hash table are nonetheless fine */
if ( ( outputDirective = = fillOutput ) & &
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( unlikely ( op + ( litLength + 240 ) / 255 /* litlen */ + litLength /* literals */ + 2 /* offset */ + 1 /* token */ + MFLIMIT - MINMATCH /* min last literals so last match is <= end - MFLIMIT */ > olimit ) ) ) {
op - - ;
goto _last_literals ;
}
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if ( litLength > = RUN_MASK ) {
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int len = ( int ) ( litLength - RUN_MASK ) ;
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* token = ( RUN_MASK < < ML_BITS ) ;
for ( ; len > = 255 ; len - = 255 ) * op + + = 255 ;
* op + + = ( BYTE ) len ;
}
else * token = ( BYTE ) ( litLength < < ML_BITS ) ;
/* Copy Literals */
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LZ4_wildCopy8 ( op , anchor , op + litLength ) ;
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op + = litLength ;
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DEBUGLOG ( 6 , " seq.start:%i, literals=%u, match.start:%i " ,
( int ) ( anchor - ( const BYTE * ) source ) , litLength , ( int ) ( ip - ( const BYTE * ) source ) ) ;
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}
_next_match :
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/* at this stage, the following variables must be correctly set :
* - ip : at start of LZ operation
* - match : at start of previous pattern occurence ; can be within current prefix , or within extDict
* - offset : if maybe_ext_memSegment = = 1 ( constant )
* - lowLimit : must be = = dictionary to mean " match is within extDict " ; must be = = source otherwise
* - token and * token : position to write 4 - bits for match length ; higher 4 - bits for literal length supposed already written
*/
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if ( ( outputDirective = = fillOutput ) & &
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( op + 2 /* offset */ + 1 /* token */ + MFLIMIT - MINMATCH /* min last literals so last match is <= end - MFLIMIT */ > olimit ) ) {
/* the match was too close to the end, rewind and go to last literals */
op = token ;
goto _last_literals ;
}
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/* Encode Offset */
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if ( maybe_extMem ) { /* static test */
DEBUGLOG ( 6 , " with offset=%u (ext if > %i) " , offset , ( int ) ( ip - ( const BYTE * ) source ) ) ;
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assert ( offset < = LZ4_DISTANCE_MAX & & offset > 0 ) ;
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LZ4_writeLE16 ( op , ( U16 ) offset ) ; op + = 2 ;
} else {
DEBUGLOG ( 6 , " with offset=%u (same segment) " , ( U32 ) ( ip - match ) ) ;
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assert ( ip - match < = LZ4_DISTANCE_MAX ) ;
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LZ4_writeLE16 ( op , ( U16 ) ( ip - match ) ) ; op + = 2 ;
}
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/* Encode MatchLength */
{ unsigned matchCode ;
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if ( ( dictDirective = = usingExtDict | | dictDirective = = usingDictCtx )
& & ( lowLimit = = dictionary ) /* match within extDict */ ) {
const BYTE * limit = ip + ( dictEnd - match ) ;
assert ( dictEnd > match ) ;
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if ( limit > matchlimit ) limit = matchlimit ;
matchCode = LZ4_count ( ip + MINMATCH , match + MINMATCH , limit ) ;
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ip + = ( size_t ) matchCode + MINMATCH ;
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if ( ip = = limit ) {
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unsigned const more = LZ4_count ( limit , ( const BYTE * ) source , matchlimit ) ;
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matchCode + = more ;
ip + = more ;
}
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DEBUGLOG ( 6 , " with matchLength=%u starting in extDict " , matchCode + MINMATCH ) ;
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} else {
matchCode = LZ4_count ( ip + MINMATCH , match + MINMATCH , matchlimit ) ;
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ip + = ( size_t ) matchCode + MINMATCH ;
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DEBUGLOG ( 6 , " with matchLength=%u " , matchCode + MINMATCH ) ;
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}
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if ( ( outputDirective ) & & /* Check output buffer overflow */
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( unlikely ( op + ( 1 + LASTLITERALS ) + ( matchCode > > 8 ) > olimit ) ) ) {
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if ( outputDirective = = fillOutput ) {
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/* Match description too long : reduce it */
U32 newMatchCode = 15 /* in token */ - 1 /* to avoid needing a zero byte */ + ( ( U32 ) ( olimit - op ) - 2 - 1 - LASTLITERALS ) * 255 ;
ip - = matchCode - newMatchCode ;
matchCode = newMatchCode ;
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} else {
assert ( outputDirective = = limitedOutput ) ;
return 0 ; /* cannot compress within `dst` budget. Stored indexes in hash table are nonetheless fine */
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}
}
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if ( matchCode > = ML_MASK ) {
* token + = ML_MASK ;
matchCode - = ML_MASK ;
LZ4_write32 ( op , 0xFFFFFFFF ) ;
while ( matchCode > = 4 * 255 ) {
op + = 4 ;
LZ4_write32 ( op , 0xFFFFFFFF ) ;
matchCode - = 4 * 255 ;
}
op + = matchCode / 255 ;
* op + + = ( BYTE ) ( matchCode % 255 ) ;
} else
* token + = ( BYTE ) ( matchCode ) ;
}
anchor = ip ;
/* Test end of chunk */
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if ( ip > = mflimitPlusOne ) break ;
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/* Fill table */
LZ4_putPosition ( ip - 2 , cctx - > hashTable , tableType , base ) ;
/* Test next position */
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if ( tableType = = byPtr ) {
match = LZ4_getPosition ( ip , cctx - > hashTable , tableType , base ) ;
LZ4_putPosition ( ip , cctx - > hashTable , tableType , base ) ;
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if ( ( match + LZ4_DISTANCE_MAX > = ip )
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& & ( LZ4_read32 ( match ) = = LZ4_read32 ( ip ) ) )
{ token = op + + ; * token = 0 ; goto _next_match ; }
} else { /* byU32, byU16 */
U32 const h = LZ4_hashPosition ( ip , tableType ) ;
U32 const current = ( U32 ) ( ip - base ) ;
U32 matchIndex = LZ4_getIndexOnHash ( h , cctx - > hashTable , tableType ) ;
assert ( matchIndex < current ) ;
if ( dictDirective = = usingDictCtx ) {
if ( matchIndex < startIndex ) {
/* there was no match, try the dictionary */
matchIndex = LZ4_getIndexOnHash ( h , dictCtx - > hashTable , byU32 ) ;
match = dictBase + matchIndex ;
lowLimit = dictionary ; /* required for match length counter */
matchIndex + = dictDelta ;
} else {
match = base + matchIndex ;
lowLimit = ( const BYTE * ) source ; /* required for match length counter */
}
} else if ( dictDirective = = usingExtDict ) {
if ( matchIndex < startIndex ) {
match = dictBase + matchIndex ;
lowLimit = dictionary ; /* required for match length counter */
} else {
match = base + matchIndex ;
lowLimit = ( const BYTE * ) source ; /* required for match length counter */
}
} else { /* single memory segment */
match = base + matchIndex ;
}
LZ4_putIndexOnHash ( current , h , cctx - > hashTable , tableType ) ;
assert ( matchIndex < current ) ;
if ( ( ( dictIssue = = dictSmall ) ? ( matchIndex > = prefixIdxLimit ) : 1 )
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& & ( ( tableType = = byU16 ) ? 1 : ( matchIndex + LZ4_DISTANCE_MAX > = current ) )
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& & ( LZ4_read32 ( match ) = = LZ4_read32 ( ip ) ) ) {
token = op + + ;
* token = 0 ;
if ( maybe_extMem ) offset = current - matchIndex ;
DEBUGLOG ( 6 , " seq.start:%i, literals=%u, match.start:%i " ,
( int ) ( anchor - ( const BYTE * ) source ) , 0 , ( int ) ( ip - ( const BYTE * ) source ) ) ;
goto _next_match ;
}
}
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/* Prepare next loop */
forwardH = LZ4_hashPosition ( + + ip , tableType ) ;
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}
_last_literals :
/* Encode Last Literals */
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{ size_t lastRun = ( size_t ) ( iend - anchor ) ;
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if ( ( outputDirective ) & & /* Check output buffer overflow */
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( op + lastRun + 1 + ( ( lastRun + 255 - RUN_MASK ) / 255 ) > olimit ) ) {
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if ( outputDirective = = fillOutput ) {
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/* adapt lastRun to fill 'dst' */
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assert ( olimit > = op ) ;
lastRun = ( size_t ) ( olimit - op ) - 1 ;
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lastRun - = ( lastRun + 240 ) / 255 ;
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} else {
assert ( outputDirective = = limitedOutput ) ;
return 0 ; /* cannot compress within `dst` budget. Stored indexes in hash table are nonetheless fine */
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}
}
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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 ) ;
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ip = anchor + lastRun ;
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op + = lastRun ;
}
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if ( outputDirective = = fillOutput ) {
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* inputConsumed = ( int ) ( ( ( const char * ) ip ) - source ) ;
}
DEBUGLOG ( 5 , " LZ4_compress_generic: compressed %i bytes into %i bytes " , inputSize , ( int ) ( ( ( char * ) op ) - dest ) ) ;
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result = ( int ) ( ( ( char * ) op ) - dest ) ;
assert ( result > 0 ) ;
return result ;
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}
int LZ4_compress_fast_extState ( void * state , const char * source , char * dest , int inputSize , int maxOutputSize , int acceleration )
{
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LZ4_stream_t_internal * const ctx = & LZ4_initStream ( state , sizeof ( LZ4_stream_t ) ) - > internal_donotuse ;
assert ( ctx ! = NULL ) ;
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if ( acceleration < 1 ) acceleration = ACCELERATION_DEFAULT ;
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if ( maxOutputSize > = LZ4_compressBound ( inputSize ) ) {
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if ( inputSize < LZ4_64Klimit ) {
return LZ4_compress_generic ( ctx , source , dest , inputSize , NULL , 0 , notLimited , byU16 , noDict , noDictIssue , acceleration ) ;
} else {
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const tableType_t tableType = ( ( sizeof ( void * ) = = 4 ) & & ( ( uptrval ) source > LZ4_DISTANCE_MAX ) ) ? byPtr : byU32 ;
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return LZ4_compress_generic ( ctx , source , dest , inputSize , NULL , 0 , notLimited , tableType , noDict , noDictIssue , acceleration ) ;
}
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} else {
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if ( inputSize < LZ4_64Klimit ) { ;
return LZ4_compress_generic ( ctx , source , dest , inputSize , NULL , maxOutputSize , limitedOutput , byU16 , noDict , noDictIssue , acceleration ) ;
} else {
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const tableType_t tableType = ( ( sizeof ( void * ) = = 4 ) & & ( ( uptrval ) source > LZ4_DISTANCE_MAX ) ) ? byPtr : byU32 ;
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return LZ4_compress_generic ( ctx , source , dest , inputSize , NULL , maxOutputSize , limitedOutput , tableType , noDict , noDictIssue , acceleration ) ;
}
}
}
/**
* LZ4_compress_fast_extState_fastReset ( ) :
* A variant of LZ4_compress_fast_extState ( ) .
*
* Using this variant avoids an expensive initialization step . It is only safe
* to call if the state buffer is known to be correctly initialized already
* ( see comment in lz4 . h on LZ4_resetStream_fast ( ) for a definition of
* " correctly initialized " ) .
*/
int LZ4_compress_fast_extState_fastReset ( void * state , const char * src , char * dst , int srcSize , int dstCapacity , int acceleration )
{
LZ4_stream_t_internal * ctx = & ( ( LZ4_stream_t * ) state ) - > internal_donotuse ;
if ( acceleration < 1 ) acceleration = ACCELERATION_DEFAULT ;
if ( dstCapacity > = LZ4_compressBound ( srcSize ) ) {
if ( srcSize < LZ4_64Klimit ) {
const tableType_t tableType = byU16 ;
LZ4_prepareTable ( ctx , srcSize , tableType ) ;
if ( ctx - > currentOffset ) {
return LZ4_compress_generic ( ctx , src , dst , srcSize , NULL , 0 , notLimited , tableType , noDict , dictSmall , acceleration ) ;
} else {
return LZ4_compress_generic ( ctx , src , dst , srcSize , NULL , 0 , notLimited , tableType , noDict , noDictIssue , acceleration ) ;
}
} else {
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const tableType_t tableType = ( ( sizeof ( void * ) = = 4 ) & & ( ( uptrval ) src > LZ4_DISTANCE_MAX ) ) ? byPtr : byU32 ;
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LZ4_prepareTable ( ctx , srcSize , tableType ) ;
return LZ4_compress_generic ( ctx , src , dst , srcSize , NULL , 0 , notLimited , tableType , noDict , noDictIssue , acceleration ) ;
}
} else {
if ( srcSize < LZ4_64Klimit ) {
const tableType_t tableType = byU16 ;
LZ4_prepareTable ( ctx , srcSize , tableType ) ;
if ( ctx - > currentOffset ) {
return LZ4_compress_generic ( ctx , src , dst , srcSize , NULL , dstCapacity , limitedOutput , tableType , noDict , dictSmall , acceleration ) ;
} else {
return LZ4_compress_generic ( ctx , src , dst , srcSize , NULL , dstCapacity , limitedOutput , tableType , noDict , noDictIssue , acceleration ) ;
}
} else {
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const tableType_t tableType = ( ( sizeof ( void * ) = = 4 ) & & ( ( uptrval ) src > LZ4_DISTANCE_MAX ) ) ? byPtr : byU32 ;
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LZ4_prepareTable ( ctx , srcSize , tableType ) ;
return LZ4_compress_generic ( ctx , src , dst , srcSize , NULL , dstCapacity , limitedOutput , tableType , noDict , noDictIssue , acceleration ) ;
}
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}
}
int LZ4_compress_fast ( const char * source , char * dest , int inputSize , int maxOutputSize , int acceleration )
{
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int result ;
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# if (LZ4_HEAPMODE)
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LZ4_stream_t * ctxPtr = ALLOC ( sizeof ( LZ4_stream_t ) ) ; /* malloc-calloc always properly aligned */
if ( ctxPtr = = NULL ) return 0 ;
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# else
LZ4_stream_t ctx ;
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LZ4_stream_t * const ctxPtr = & ctx ;
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# endif
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result = LZ4_compress_fast_extState ( ctxPtr , source , dest , inputSize , maxOutputSize , acceleration ) ;
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# if (LZ4_HEAPMODE)
FREEMEM ( ctxPtr ) ;
# endif
return result ;
}
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int LZ4_compress_default ( const char * src , char * dst , int srcSize , int maxOutputSize )
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{
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return LZ4_compress_fast ( src , dst , srcSize , maxOutputSize , 1 ) ;
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}
/* hidden debug function */
/* strangely enough, gcc generates faster code when this function is uncommented, even if unused */
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int LZ4_compress_fast_force ( const char * src , char * dst , int srcSize , int dstCapacity , int acceleration )
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{
LZ4_stream_t ctx ;
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LZ4_initStream ( & ctx , sizeof ( ctx ) ) ;
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if ( srcSize < LZ4_64Klimit ) {
return LZ4_compress_generic ( & ctx . internal_donotuse , src , dst , srcSize , NULL , dstCapacity , limitedOutput , byU16 , noDict , noDictIssue , acceleration ) ;
} else {
tableType_t const addrMode = ( sizeof ( void * ) > 4 ) ? byU32 : byPtr ;
return LZ4_compress_generic ( & ctx . internal_donotuse , src , dst , srcSize , NULL , dstCapacity , limitedOutput , addrMode , noDict , noDictIssue , acceleration ) ;
}
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}
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/* Note!: This function leaves the stream in an unclean/broken state!
* It is not safe to subsequently use the same state with a _fastReset ( ) or
* _continue ( ) call without resetting it . */
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static int LZ4_compress_destSize_extState ( LZ4_stream_t * state , const char * src , char * dst , int * srcSizePtr , int targetDstSize )
{
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void * const s = LZ4_initStream ( state , sizeof ( * state ) ) ;
assert ( s ! = NULL ) ; ( void ) s ;
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if ( targetDstSize > = LZ4_compressBound ( * srcSizePtr ) ) { /* compression success is guaranteed */
return LZ4_compress_fast_extState ( state , src , dst , * srcSizePtr , targetDstSize , 1 ) ;
} else {
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if ( * srcSizePtr < LZ4_64Klimit ) {
return LZ4_compress_generic ( & state - > internal_donotuse , src , dst , * srcSizePtr , srcSizePtr , targetDstSize , fillOutput , byU16 , noDict , noDictIssue , 1 ) ;
} else {
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tableType_t const addrMode = ( ( sizeof ( void * ) = = 4 ) & & ( ( uptrval ) src > LZ4_DISTANCE_MAX ) ) ? byPtr : byU32 ;
return LZ4_compress_generic ( & state - > internal_donotuse , src , dst , * srcSizePtr , srcSizePtr , targetDstSize , fillOutput , addrMode , noDict , noDictIssue , 1 ) ;
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} }
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}
int LZ4_compress_destSize ( const char * src , char * dst , int * srcSizePtr , int targetDstSize )
{
# if (LZ4_HEAPMODE)
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LZ4_stream_t * ctx = ( LZ4_stream_t * ) ALLOC ( sizeof ( LZ4_stream_t ) ) ; /* malloc-calloc always properly aligned */
if ( ctx = = NULL ) return 0 ;
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# else
LZ4_stream_t ctxBody ;
LZ4_stream_t * ctx = & ctxBody ;
# endif
int result = LZ4_compress_destSize_extState ( ctx , src , dst , srcSizePtr , targetDstSize ) ;
# if (LZ4_HEAPMODE)
FREEMEM ( ctx ) ;
# endif
return result ;
}
/*-******************************
* Streaming functions
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
LZ4_stream_t * LZ4_createStream ( void )
{
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LZ4_stream_t * const lz4s = ( LZ4_stream_t * ) ALLOC ( sizeof ( LZ4_stream_t ) ) ;
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LZ4_STATIC_ASSERT ( LZ4_STREAMSIZE > = sizeof ( LZ4_stream_t_internal ) ) ; /* A compilation error here means LZ4_STREAMSIZE is not large enough */
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DEBUGLOG ( 4 , " LZ4_createStream %p " , lz4s ) ;
if ( lz4s = = NULL ) return NULL ;
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LZ4_initStream ( lz4s , sizeof ( * lz4s ) ) ;
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return lz4s ;
}
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# ifndef _MSC_VER / * for some reason, Visual fails the aligment test on 32-bit x86 :
it reports an aligment of 8 - bytes ,
while actually aligning LZ4_stream_t on 4 bytes . */
static size_t LZ4_stream_t_alignment ( void )
{
struct { char c ; LZ4_stream_t t ; } t_a ;
return sizeof ( t_a ) - sizeof ( t_a . t ) ;
}
# endif
LZ4_stream_t * LZ4_initStream ( void * buffer , size_t size )
{
DEBUGLOG ( 5 , " LZ4_initStream " ) ;
if ( buffer = = NULL ) return NULL ;
if ( size < sizeof ( LZ4_stream_t ) ) return NULL ;
# ifndef _MSC_VER / * for some reason, Visual fails the aligment test on 32-bit x86 :
it reports an aligment of 8 - bytes ,
while actually aligning LZ4_stream_t on 4 bytes . */
if ( ( ( size_t ) buffer ) & ( LZ4_stream_t_alignment ( ) - 1 ) ) return NULL ; /* alignment check */
# endif
MEM_INIT ( buffer , 0 , sizeof ( LZ4_stream_t ) ) ;
return ( LZ4_stream_t * ) buffer ;
}
/* resetStream is now deprecated,
* prefer initStream ( ) which is more general */
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void LZ4_resetStream ( LZ4_stream_t * LZ4_stream )
{
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DEBUGLOG ( 5 , " LZ4_resetStream (ctx:%p) " , LZ4_stream ) ;
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MEM_INIT ( LZ4_stream , 0 , sizeof ( LZ4_stream_t ) ) ;
}
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void LZ4_resetStream_fast ( LZ4_stream_t * ctx ) {
LZ4_prepareTable ( & ( ctx - > internal_donotuse ) , 0 , byU32 ) ;
}
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int LZ4_freeStream ( LZ4_stream_t * LZ4_stream )
{
if ( ! LZ4_stream ) return 0 ; /* support free on NULL */
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DEBUGLOG ( 5 , " LZ4_freeStream %p " , LZ4_stream ) ;
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FREEMEM ( LZ4_stream ) ;
return ( 0 ) ;
}
# define HASH_UNIT sizeof(reg_t)
int LZ4_loadDict ( LZ4_stream_t * LZ4_dict , const char * dictionary , int dictSize )
{
LZ4_stream_t_internal * dict = & LZ4_dict - > internal_donotuse ;
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const tableType_t tableType = byU32 ;
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const BYTE * p = ( const BYTE * ) dictionary ;
const BYTE * const dictEnd = p + dictSize ;
const BYTE * base ;
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DEBUGLOG ( 4 , " LZ4_loadDict (%i bytes from %p into %p) " , dictSize , dictionary , LZ4_dict ) ;
2017-09-11 23:25:50 +00:00
2018-05-07 23:52:40 +00:00
/* It's necessary to reset the context,
* and not just continue it with prepareTable ( )
* to avoid any risk of generating overflowing matchIndex
* when compressing using this dictionary */
LZ4_resetStream ( LZ4_dict ) ;
/* We always increment the offset by 64 KB, since, if the dict is longer,
* we truncate it to the last 64 k , and if it ' s shorter , we still want to
* advance by a whole window length so we can provide the guarantee that
* there are only valid offsets in the window , which allows an optimization
* in LZ4_compress_fast_continue ( ) where it uses noDictIssue even when the
* dictionary isn ' t a full 64 k . */
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if ( ( dictEnd - p ) > 64 KB ) p = dictEnd - 64 KB ;
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base = dictEnd - 64 KB - dict - > currentOffset ;
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dict - > dictionary = p ;
dict - > dictSize = ( U32 ) ( dictEnd - p ) ;
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dict - > currentOffset + = 64 KB ;
dict - > tableType = tableType ;
if ( dictSize < ( int ) HASH_UNIT ) {
return 0 ;
}
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while ( p < = dictEnd - HASH_UNIT ) {
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LZ4_putPosition ( p , dict - > hashTable , tableType , base ) ;
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p + = 3 ;
}
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return ( int ) dict - > dictSize ;
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}
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void LZ4_attach_dictionary ( LZ4_stream_t * working_stream , const LZ4_stream_t * dictionary_stream ) {
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/* Calling LZ4_resetStream_fast() here makes sure that changes will not be
* erased by subsequent calls to LZ4_resetStream_fast ( ) in case stream was
* marked as having dirty context , e . g . requiring full reset .
*/
LZ4_resetStream_fast ( working_stream ) ;
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if ( dictionary_stream ! = NULL ) {
/* If the current offset is zero, we will never look in the
* external dictionary context , since there is no value a table
* entry can take that indicate a miss . In that case , we need
* to bump the offset to something non - zero .
*/
if ( working_stream - > internal_donotuse . currentOffset = = 0 ) {
working_stream - > internal_donotuse . currentOffset = 64 KB ;
}
working_stream - > internal_donotuse . dictCtx = & ( dictionary_stream - > internal_donotuse ) ;
} else {
working_stream - > internal_donotuse . dictCtx = NULL ;
}
}
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2018-05-07 23:52:40 +00:00
static void LZ4_renormDictT ( LZ4_stream_t_internal * LZ4_dict , int nextSize )
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{
2019-05-01 14:53:48 +00:00
assert ( nextSize > = 0 ) ;
if ( LZ4_dict - > currentOffset + ( unsigned ) nextSize > 0x80000000 ) { /* potential ptrdiff_t overflow (32-bits mode) */
2017-09-11 23:25:50 +00:00
/* rescale hash table */
U32 const delta = LZ4_dict - > currentOffset - 64 KB ;
const BYTE * dictEnd = LZ4_dict - > dictionary + LZ4_dict - > dictSize ;
int i ;
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DEBUGLOG ( 4 , " LZ4_renormDictT " ) ;
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for ( i = 0 ; i < LZ4_HASH_SIZE_U32 ; i + + ) {
if ( LZ4_dict - > hashTable [ i ] < delta ) LZ4_dict - > hashTable [ i ] = 0 ;
else LZ4_dict - > hashTable [ i ] - = delta ;
}
LZ4_dict - > currentOffset = 64 KB ;
if ( LZ4_dict - > dictSize > 64 KB ) LZ4_dict - > dictSize = 64 KB ;
LZ4_dict - > dictionary = dictEnd - LZ4_dict - > dictSize ;
}
}
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int LZ4_compress_fast_continue ( LZ4_stream_t * LZ4_stream ,
const char * source , char * dest ,
int inputSize , int maxOutputSize ,
int acceleration )
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{
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const tableType_t tableType = byU32 ;
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LZ4_stream_t_internal * streamPtr = & LZ4_stream - > internal_donotuse ;
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const BYTE * dictEnd = streamPtr - > dictionary + streamPtr - > dictSize ;
DEBUGLOG ( 5 , " LZ4_compress_fast_continue (inputSize=%i) " , inputSize ) ;
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if ( streamPtr - > dirty ) return 0 ; /* Uninitialized structure detected */
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LZ4_renormDictT ( streamPtr , inputSize ) ; /* avoid index overflow */
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if ( acceleration < 1 ) acceleration = ACCELERATION_DEFAULT ;
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/* invalidate tiny dictionaries */
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if ( ( streamPtr - > dictSize - 1 < 4 - 1 ) /* intentional underflow */
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& & ( dictEnd ! = ( const BYTE * ) source ) ) {
DEBUGLOG ( 5 , " LZ4_compress_fast_continue: dictSize(%u) at addr:%p is too small " , streamPtr - > dictSize , streamPtr - > dictionary ) ;
streamPtr - > dictSize = 0 ;
streamPtr - > dictionary = ( const BYTE * ) source ;
dictEnd = ( const BYTE * ) source ;
}
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/* Check overlapping input/dictionary space */
{ const BYTE * sourceEnd = ( const BYTE * ) source + inputSize ;
if ( ( sourceEnd > streamPtr - > dictionary ) & & ( sourceEnd < dictEnd ) ) {
streamPtr - > dictSize = ( U32 ) ( dictEnd - sourceEnd ) ;
if ( streamPtr - > dictSize > 64 KB ) streamPtr - > dictSize = 64 KB ;
if ( streamPtr - > dictSize < 4 ) streamPtr - > dictSize = 0 ;
streamPtr - > dictionary = dictEnd - streamPtr - > dictSize ;
}
}
/* prefix mode : source data follows dictionary */
if ( dictEnd = = ( const BYTE * ) source ) {
if ( ( streamPtr - > dictSize < 64 KB ) & & ( streamPtr - > dictSize < streamPtr - > currentOffset ) )
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return LZ4_compress_generic ( streamPtr , source , dest , inputSize , NULL , maxOutputSize , limitedOutput , tableType , withPrefix64k , dictSmall , acceleration ) ;
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else
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return LZ4_compress_generic ( streamPtr , source , dest , inputSize , NULL , maxOutputSize , limitedOutput , tableType , withPrefix64k , noDictIssue , acceleration ) ;
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}
/* external dictionary mode */
{ int result ;
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if ( streamPtr - > dictCtx ) {
/* We depend here on the fact that dictCtx'es (produced by
* LZ4_loadDict ) guarantee that their tables contain no references
* to offsets between dictCtx - > currentOffset - 64 KB and
* dictCtx - > currentOffset - dictCtx - > dictSize . This makes it safe
* to use noDictIssue even when the dict isn ' t a full 64 KB .
*/
if ( inputSize > 4 KB ) {
/* For compressing large blobs, it is faster to pay the setup
* cost to copy the dictionary ' s tables into the active context ,
* so that the compression loop is only looking into one table .
*/
memcpy ( streamPtr , streamPtr - > dictCtx , sizeof ( LZ4_stream_t ) ) ;
result = LZ4_compress_generic ( streamPtr , source , dest , inputSize , NULL , maxOutputSize , limitedOutput , tableType , usingExtDict , noDictIssue , acceleration ) ;
} else {
result = LZ4_compress_generic ( streamPtr , source , dest , inputSize , NULL , maxOutputSize , limitedOutput , tableType , usingDictCtx , noDictIssue , acceleration ) ;
}
} else {
if ( ( streamPtr - > dictSize < 64 KB ) & & ( streamPtr - > dictSize < streamPtr - > currentOffset ) ) {
result = LZ4_compress_generic ( streamPtr , source , dest , inputSize , NULL , maxOutputSize , limitedOutput , tableType , usingExtDict , dictSmall , acceleration ) ;
} else {
result = LZ4_compress_generic ( streamPtr , source , dest , inputSize , NULL , maxOutputSize , limitedOutput , tableType , usingExtDict , noDictIssue , acceleration ) ;
}
}
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streamPtr - > dictionary = ( const BYTE * ) source ;
streamPtr - > dictSize = ( U32 ) inputSize ;
return result ;
}
}
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/* Hidden debug function, to force-test external dictionary mode */
int LZ4_compress_forceExtDict ( LZ4_stream_t * LZ4_dict , const char * source , char * dest , int srcSize )
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{
LZ4_stream_t_internal * streamPtr = & LZ4_dict - > internal_donotuse ;
int result ;
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LZ4_renormDictT ( streamPtr , srcSize ) ;
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if ( ( streamPtr - > dictSize < 64 KB ) & & ( streamPtr - > dictSize < streamPtr - > currentOffset ) ) {
result = LZ4_compress_generic ( streamPtr , source , dest , srcSize , NULL , 0 , notLimited , byU32 , usingExtDict , dictSmall , 1 ) ;
} else {
result = LZ4_compress_generic ( streamPtr , source , dest , srcSize , NULL , 0 , notLimited , byU32 , usingExtDict , noDictIssue , 1 ) ;
}
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streamPtr - > dictionary = ( const BYTE * ) source ;
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streamPtr - > dictSize = ( U32 ) srcSize ;
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return result ;
}
/*! LZ4_saveDict() :
* If previously compressed data block is not guaranteed to remain available at its memory location ,
* save it into a safer place ( char * safeBuffer ) .
* Note : you don ' t need to call LZ4_loadDict ( ) afterwards ,
* dictionary is immediately usable , you can therefore call LZ4_compress_fast_continue ( ) .
* Return : saved dictionary size in bytes ( necessarily < = dictSize ) , or 0 if error .
*/
int LZ4_saveDict ( LZ4_stream_t * LZ4_dict , char * safeBuffer , int dictSize )
{
LZ4_stream_t_internal * const dict = & LZ4_dict - > internal_donotuse ;
const BYTE * const previousDictEnd = dict - > dictionary + dict - > dictSize ;
if ( ( U32 ) dictSize > 64 KB ) dictSize = 64 KB ; /* useless to define a dictionary > 64 KB */
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if ( ( U32 ) dictSize > dict - > dictSize ) dictSize = ( int ) dict - > dictSize ;
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memmove ( safeBuffer , previousDictEnd - dictSize , dictSize ) ;
dict - > dictionary = ( const BYTE * ) safeBuffer ;
dict - > dictSize = ( U32 ) dictSize ;
return dictSize ;
}
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/*-*******************************
* Decompression functions
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
typedef enum { endOnOutputSize = 0 , endOnInputSize = 1 } endCondition_directive ;
typedef enum { decode_full_block = 0 , partial_decode = 1 } earlyEnd_directive ;
# undef MIN
# define MIN(a,b) ( (a) < (b) ? (a) : (b) )
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/* Read the variable-length literal or match length.
*
* ip - pointer to use as input .
* lencheck - end ip . Return an error if ip advances > = lencheck .
* loop_check - check ip > = lencheck in body of loop . Returns loop_error if so .
* initial_check - check ip > = lencheck before start of loop . Returns initial_error if so .
* error ( output ) - error code . Should be set to 0 before call .
*/
typedef enum { loop_error = - 2 , initial_error = - 1 , ok = 0 } variable_length_error ;
LZ4_FORCE_INLINE unsigned
read_variable_length ( const BYTE * * ip , const BYTE * lencheck , int loop_check , int initial_check , variable_length_error * error )
{
unsigned length = 0 ;
unsigned s ;
if ( initial_check & & unlikely ( ( * ip ) > = lencheck ) ) { /* overflow detection */
* error = initial_error ;
return length ;
}
do {
s = * * ip ;
( * ip ) + + ;
length + = s ;
if ( loop_check & & unlikely ( ( * ip ) > = lencheck ) ) { /* overflow detection */
* error = loop_error ;
return length ;
}
} while ( s = = 255 ) ;
return length ;
}
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/*! LZ4_decompress_generic() :
* This generic decompression function covers all use cases .
* It shall be instantiated several times , using different sets of directives .
* Note that it is important for performance that this function really get inlined ,
* in order to remove useless branches during compilation optimization .
*/
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LZ4_FORCE_INLINE int
LZ4_decompress_generic (
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const char * const src ,
char * const dst ,
int srcSize ,
int outputSize , /* If endOnInput==endOnInputSize, this value is `dstCapacity` */
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endCondition_directive endOnInput , /* endOnOutputSize, endOnInputSize */
earlyEnd_directive partialDecoding , /* full, partial */
dict_directive dict , /* noDict, withPrefix64k, usingExtDict */
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const BYTE * const lowPrefix , /* always <= dst, == dst when no prefix */
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const BYTE * const dictStart , /* only if dict==usingExtDict */
const size_t dictSize /* note : = 0 if noDict */
)
{
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if ( src = = NULL ) return - 1 ;
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{ const BYTE * ip = ( const BYTE * ) src ;
const BYTE * const iend = ip + srcSize ;
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BYTE * op = ( BYTE * ) dst ;
BYTE * const oend = op + outputSize ;
BYTE * cpy ;
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const BYTE * const dictEnd = ( dictStart = = NULL ) ? NULL : dictStart + dictSize ;
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const int safeDecode = ( endOnInput = = endOnInputSize ) ;
const int checkOffset = ( ( safeDecode ) & & ( dictSize < ( int ) ( 64 KB ) ) ) ;
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/* Set up the "end" pointers for the shortcut. */
const BYTE * const shortiend = iend - ( endOnInput ? 14 : 8 ) /*maxLL*/ - 2 /*offset*/ ;
const BYTE * const shortoend = oend - ( endOnInput ? 14 : 8 ) /*maxLL*/ - 18 /*maxML*/ ;
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const BYTE * match ;
size_t offset ;
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unsigned token ;
size_t length ;
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DEBUGLOG ( 5 , " LZ4_decompress_generic (srcSize:%i, dstSize:%i) " , srcSize , outputSize ) ;
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/* Special cases */
assert ( lowPrefix < = op ) ;
if ( ( endOnInput ) & & ( unlikely ( outputSize = = 0 ) ) ) return ( ( srcSize = = 1 ) & & ( * ip = = 0 ) ) ? 0 : - 1 ; /* Empty output buffer */
if ( ( ! endOnInput ) & & ( unlikely ( outputSize = = 0 ) ) ) return ( * ip = = 0 ? 1 : - 1 ) ;
if ( ( endOnInput ) & & unlikely ( srcSize = = 0 ) ) return - 1 ;
/* Currently the fast loop shows a regression on qualcomm arm chips. */
# if LZ4_FAST_DEC_LOOP
if ( ( oend - op ) < FASTLOOP_SAFE_DISTANCE ) {
DEBUGLOG ( 6 , " skip fast decode loop " ) ;
goto safe_decode ;
}
/* Fast loop : decode sequences as long as output < iend-FASTLOOP_SAFE_DISTANCE */
while ( 1 ) {
/* Main fastloop assertion: We can always wildcopy FASTLOOP_SAFE_DISTANCE */
assert ( oend - op > = FASTLOOP_SAFE_DISTANCE ) ;
if ( endOnInput ) assert ( ip < iend ) ;
token = * ip + + ;
length = token > > ML_BITS ; /* literal length */
assert ( ! endOnInput | | ip < = iend ) ; /* ip < iend before the increment */
/* decode literal length */
if ( length = = RUN_MASK ) {
variable_length_error error = ok ;
length + = read_variable_length ( & ip , iend - RUN_MASK , endOnInput , endOnInput , & error ) ;
if ( error = = initial_error ) goto _output_error ;
if ( ( safeDecode ) & & unlikely ( ( uptrval ) ( op ) + length < ( uptrval ) ( op ) ) ) goto _output_error ; /* overflow detection */
if ( ( safeDecode ) & & unlikely ( ( uptrval ) ( ip ) + length < ( uptrval ) ( ip ) ) ) goto _output_error ; /* overflow detection */
/* copy literals */
cpy = op + length ;
LZ4_STATIC_ASSERT ( MFLIMIT > = WILDCOPYLENGTH ) ;
if ( endOnInput ) { /* LZ4_decompress_safe() */
if ( ( cpy > oend - 32 ) | | ( ip + length > iend - 32 ) ) goto safe_literal_copy ;
LZ4_wildCopy32 ( op , ip , cpy ) ;
} else { /* LZ4_decompress_fast() */
if ( cpy > oend - 8 ) goto safe_literal_copy ;
LZ4_wildCopy8 ( op , ip , cpy ) ; /* LZ4_decompress_fast() cannot copy more than 8 bytes at a time :
* it doesn ' t know input length , and only relies on end - of - block properties */
}
ip + = length ; op = cpy ;
} else {
cpy = op + length ;
if ( endOnInput ) { /* LZ4_decompress_safe() */
DEBUGLOG ( 7 , " copy %u bytes in a 16-bytes stripe " , ( unsigned ) length ) ;
/* We don't need to check oend, since we check it once for each loop below */
if ( ip > iend - ( 16 + 1 /*max lit + offset + nextToken*/ ) ) goto safe_literal_copy ;
/* Literals can only be 14, but hope compilers optimize if we copy by a register size */
memcpy ( op , ip , 16 ) ;
} else { /* LZ4_decompress_fast() */
/* LZ4_decompress_fast() cannot copy more than 8 bytes at a time :
* it doesn ' t know input length , and relies on end - of - block properties */
memcpy ( op , ip , 8 ) ;
if ( length > 8 ) memcpy ( op + 8 , ip + 8 , 8 ) ;
}
ip + = length ; op = cpy ;
}
/* get offset */
offset = LZ4_readLE16 ( ip ) ; ip + = 2 ;
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match = op - offset ;
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/* get matchlength */
length = token & ML_MASK ;
if ( ( checkOffset ) & & ( unlikely ( match + dictSize < lowPrefix ) ) ) goto _output_error ; /* Error : offset outside buffers */
if ( length = = ML_MASK ) {
variable_length_error error = ok ;
length + = read_variable_length ( & ip , iend - LASTLITERALS + 1 , endOnInput , 0 , & error ) ;
if ( error ! = ok ) goto _output_error ;
if ( ( safeDecode ) & & unlikely ( ( uptrval ) ( op ) + length < ( uptrval ) op ) ) goto _output_error ; /* overflow detection */
length + = MINMATCH ;
if ( op + length > = oend - FASTLOOP_SAFE_DISTANCE ) {
goto safe_match_copy ;
}
} else {
length + = MINMATCH ;
if ( op + length > = oend - FASTLOOP_SAFE_DISTANCE ) {
goto safe_match_copy ;
}
/* Fastpath check: Avoids a branch in LZ4_wildCopy32 if true */
if ( ! ( dict = = usingExtDict ) | | ( match > = lowPrefix ) ) {
if ( offset > = 8 ) {
memcpy ( op , match , 8 ) ;
memcpy ( op + 8 , match + 8 , 8 ) ;
memcpy ( op + 16 , match + 16 , 2 ) ;
op + = length ;
continue ;
} } }
/* match starting within external dictionary */
if ( ( dict = = usingExtDict ) & & ( match < lowPrefix ) ) {
if ( unlikely ( op + length > oend - LASTLITERALS ) ) {
if ( partialDecoding ) length = MIN ( length , ( size_t ) ( oend - op ) ) ;
else goto _output_error ; /* doesn't respect parsing restriction */
}
if ( length < = ( size_t ) ( lowPrefix - match ) ) {
/* match fits entirely within external dictionary : just copy */
memmove ( op , dictEnd - ( lowPrefix - match ) , length ) ;
op + = length ;
} else {
/* match stretches into both external dictionary and current block */
size_t const copySize = ( size_t ) ( lowPrefix - match ) ;
size_t const restSize = length - copySize ;
memcpy ( op , dictEnd - copySize , copySize ) ;
op + = copySize ;
if ( restSize > ( size_t ) ( op - lowPrefix ) ) { /* overlap copy */
BYTE * const endOfMatch = op + restSize ;
const BYTE * copyFrom = lowPrefix ;
while ( op < endOfMatch ) * op + + = * copyFrom + + ;
} else {
memcpy ( op , lowPrefix , restSize ) ;
op + = restSize ;
} }
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continue ;
}
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/* copy match within block */
cpy = op + length ;
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assert ( ( op < = oend ) & & ( oend - op > = 32 ) ) ;
if ( unlikely ( offset < 16 ) ) {
LZ4_memcpy_using_offset ( op , match , cpy , offset ) ;
} else {
LZ4_wildCopy32 ( op , match , cpy ) ;
}
op = cpy ; /* wildcopy correction */
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}
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safe_decode :
# endif
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/* Main Loop : decode remaining sequences where output < FASTLOOP_SAFE_DISTANCE */
while ( 1 ) {
token = * ip + + ;
length = token > > ML_BITS ; /* literal length */
assert ( ! endOnInput | | ip < = iend ) ; /* ip < iend before the increment */
/* A two-stage shortcut for the most common case:
* 1 ) If the literal length is 0. .14 , and there is enough space ,
* enter the shortcut and copy 16 bytes on behalf of the literals
* ( in the fast mode , only 8 bytes can be safely copied this way ) .
* 2 ) Further if the match length is 4. .18 , copy 18 bytes in a similar
* manner ; but we ensure that there ' s enough space in the output for
* those 18 bytes earlier , upon entering the shortcut ( in other words ,
* there is a combined check for both stages ) .
*/
if ( ( endOnInput ? length ! = RUN_MASK : length < = 8 )
/* strictly "less than" on input, to re-enter the loop with at least one byte */
& & likely ( ( endOnInput ? ip < shortiend : 1 ) & ( op < = shortoend ) ) ) {
/* Copy the literals */
memcpy ( op , ip , endOnInput ? 16 : 8 ) ;
op + = length ; ip + = length ;
/* The second stage: prepare for match copying, decode full info.
* If it doesn ' t work out , the info won ' t be wasted . */
length = token & ML_MASK ; /* match length */
offset = LZ4_readLE16 ( ip ) ; ip + = 2 ;
match = op - offset ;
assert ( match < = op ) ; /* check overflow */
/* Do not deal with overlapping matches. */
if ( ( length ! = ML_MASK )
& & ( offset > = 8 )
& & ( dict = = withPrefix64k | | match > = lowPrefix ) ) {
/* Copy the match. */
memcpy ( op + 0 , match + 0 , 8 ) ;
memcpy ( op + 8 , match + 8 , 8 ) ;
memcpy ( op + 16 , match + 16 , 2 ) ;
op + = length + MINMATCH ;
/* Both stages worked, load the next token. */
continue ;
}
/* The second stage didn't work out, but the info is ready.
* Propel it right to the point of match copying . */
goto _copy_match ;
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}
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/* decode literal length */
if ( length = = RUN_MASK ) {
variable_length_error error = ok ;
length + = read_variable_length ( & ip , iend - RUN_MASK , endOnInput , endOnInput , & error ) ;
if ( error = = initial_error ) goto _output_error ;
if ( ( safeDecode ) & & unlikely ( ( uptrval ) ( op ) + length < ( uptrval ) ( op ) ) ) goto _output_error ; /* overflow detection */
if ( ( safeDecode ) & & unlikely ( ( uptrval ) ( ip ) + length < ( uptrval ) ( ip ) ) ) goto _output_error ; /* overflow detection */
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}
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/* copy literals */
cpy = op + length ;
# if LZ4_FAST_DEC_LOOP
safe_literal_copy :
# endif
LZ4_STATIC_ASSERT ( MFLIMIT > = WILDCOPYLENGTH ) ;
if ( ( ( endOnInput ) & & ( ( cpy > oend - MFLIMIT ) | | ( ip + length > iend - ( 2 + 1 + LASTLITERALS ) ) ) )
| | ( ( ! endOnInput ) & & ( cpy > oend - WILDCOPYLENGTH ) ) )
{
if ( partialDecoding ) {
if ( cpy > oend ) { cpy = oend ; assert ( op < = oend ) ; length = ( size_t ) ( oend - op ) ; } /* Partial decoding : stop in the middle of literal segment */
if ( ( endOnInput ) & & ( ip + length > iend ) ) goto _output_error ; /* Error : read attempt beyond end of input buffer */
} else {
if ( ( ! endOnInput ) & & ( cpy ! = oend ) ) goto _output_error ; /* Error : block decoding must stop exactly there */
if ( ( endOnInput ) & & ( ( ip + length ! = iend ) | | ( cpy > oend ) ) ) goto _output_error ; /* Error : input must be consumed */
}
memcpy ( op , ip , length ) ;
ip + = length ;
op + = length ;
if ( ! partialDecoding | | ( cpy = = oend ) ) {
/* Necessarily EOF, due to parsing restrictions */
break ;
}
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} else {
LZ4_wildCopy8 ( op , ip , cpy ) ; /* may overwrite up to WILDCOPYLENGTH beyond cpy */
ip + = length ; op = cpy ;
}
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/* get offset */
offset = LZ4_readLE16 ( ip ) ; ip + = 2 ;
match = op - offset ;
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/* get matchlength */
length = token & ML_MASK ;
_copy_match :
if ( ( checkOffset ) & & ( unlikely ( match + dictSize < lowPrefix ) ) ) goto _output_error ; /* Error : offset outside buffers */
if ( ! partialDecoding ) {
assert ( oend > op ) ;
assert ( oend - op > = 4 ) ;
LZ4_write32 ( op , 0 ) ; /* silence an msan warning when offset==0; costs <1%; */
} /* note : when partialDecoding, there is no guarantee that at least 4 bytes remain available in output buffer */
if ( length = = ML_MASK ) {
variable_length_error error = ok ;
length + = read_variable_length ( & ip , iend - LASTLITERALS + 1 , endOnInput , 0 , & error ) ;
if ( error ! = ok ) goto _output_error ;
if ( ( safeDecode ) & & unlikely ( ( uptrval ) ( op ) + length < ( uptrval ) op ) ) goto _output_error ; /* overflow detection */
}
length + = MINMATCH ;
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# if LZ4_FAST_DEC_LOOP
safe_match_copy :
# endif
/* match starting within external dictionary */
if ( ( dict = = usingExtDict ) & & ( match < lowPrefix ) ) {
if ( unlikely ( op + length > oend - LASTLITERALS ) ) {
if ( partialDecoding ) length = MIN ( length , ( size_t ) ( oend - op ) ) ;
else goto _output_error ; /* doesn't respect parsing restriction */
}
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if ( length < = ( size_t ) ( lowPrefix - match ) ) {
/* match fits entirely within external dictionary : just copy */
memmove ( op , dictEnd - ( lowPrefix - match ) , length ) ;
op + = length ;
} else {
/* match stretches into both external dictionary and current block */
size_t const copySize = ( size_t ) ( lowPrefix - match ) ;
size_t const restSize = length - copySize ;
memcpy ( op , dictEnd - copySize , copySize ) ;
op + = copySize ;
if ( restSize > ( size_t ) ( op - lowPrefix ) ) { /* overlap copy */
BYTE * const endOfMatch = op + restSize ;
const BYTE * copyFrom = lowPrefix ;
while ( op < endOfMatch ) * op + + = * copyFrom + + ;
} else {
memcpy ( op , lowPrefix , restSize ) ;
op + = restSize ;
} }
continue ;
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}
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/* copy match within block */
cpy = op + length ;
/* partialDecoding : may end anywhere within the block */
assert ( op < = oend ) ;
if ( partialDecoding & & ( cpy > oend - MATCH_SAFEGUARD_DISTANCE ) ) {
size_t const mlen = MIN ( length , ( size_t ) ( oend - op ) ) ;
const BYTE * const matchEnd = match + mlen ;
BYTE * const copyEnd = op + mlen ;
if ( matchEnd > op ) { /* overlap copy */
while ( op < copyEnd ) * op + + = * match + + ;
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} else {
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memcpy ( op , match , mlen ) ;
}
op = copyEnd ;
if ( op = = oend ) break ;
continue ;
}
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if ( unlikely ( offset < 8 ) ) {
op [ 0 ] = match [ 0 ] ;
op [ 1 ] = match [ 1 ] ;
op [ 2 ] = match [ 2 ] ;
op [ 3 ] = match [ 3 ] ;
match + = inc32table [ offset ] ;
memcpy ( op + 4 , match , 4 ) ;
match - = dec64table [ offset ] ;
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} else {
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memcpy ( op , match , 8 ) ;
match + = 8 ;
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}
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op + = 8 ;
if ( unlikely ( cpy > oend - MATCH_SAFEGUARD_DISTANCE ) ) {
BYTE * const oCopyLimit = oend - ( WILDCOPYLENGTH - 1 ) ;
if ( cpy > oend - LASTLITERALS ) goto _output_error ; /* Error : last LASTLITERALS bytes must be literals (uncompressed) */
if ( op < oCopyLimit ) {
LZ4_wildCopy8 ( op , match , oCopyLimit ) ;
match + = oCopyLimit - op ;
op = oCopyLimit ;
}
while ( op < cpy ) * op + + = * match + + ;
} else {
memcpy ( op , match , 8 ) ;
if ( length > 16 ) LZ4_wildCopy8 ( op + 8 , match + 8 , cpy ) ;
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}
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op = cpy ; /* wildcopy correction */
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}
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/* end of decoding */
if ( endOnInput )
return ( int ) ( ( ( char * ) op ) - dst ) ; /* Nb of output bytes decoded */
else
return ( int ) ( ( ( const char * ) ip ) - src ) ; /* Nb of input bytes read */
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/* Overflow error detected */
_output_error :
return ( int ) ( - ( ( ( const char * ) ip ) - src ) ) - 1 ;
}
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}
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/*===== Instantiate the API decoding functions. =====*/
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LZ4_FORCE_O2_GCC_PPC64LE
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int LZ4_decompress_safe ( const char * source , char * dest , int compressedSize , int maxDecompressedSize )
{
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return LZ4_decompress_generic ( source , dest , compressedSize , maxDecompressedSize ,
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endOnInputSize , decode_full_block , noDict ,
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( BYTE * ) dest , NULL , 0 ) ;
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}
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LZ4_FORCE_O2_GCC_PPC64LE
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int LZ4_decompress_safe_partial ( const char * src , char * dst , int compressedSize , int targetOutputSize , int dstCapacity )
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{
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dstCapacity = MIN ( targetOutputSize , dstCapacity ) ;
return LZ4_decompress_generic ( src , dst , compressedSize , dstCapacity ,
endOnInputSize , partial_decode ,
noDict , ( BYTE * ) dst , NULL , 0 ) ;
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}
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LZ4_FORCE_O2_GCC_PPC64LE
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int LZ4_decompress_fast ( const char * source , char * dest , int originalSize )
{
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return LZ4_decompress_generic ( source , dest , 0 , originalSize ,
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endOnOutputSize , decode_full_block , withPrefix64k ,
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( BYTE * ) dest - 64 KB , NULL , 0 ) ;
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}
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/*===== Instantiate a few more decoding cases, used more than once. =====*/
LZ4_FORCE_O2_GCC_PPC64LE /* Exported, an obsolete API function. */
int LZ4_decompress_safe_withPrefix64k ( const char * source , char * dest , int compressedSize , int maxOutputSize )
{
return LZ4_decompress_generic ( source , dest , compressedSize , maxOutputSize ,
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endOnInputSize , decode_full_block , withPrefix64k ,
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( BYTE * ) dest - 64 KB , NULL , 0 ) ;
}
/* Another obsolete API function, paired with the previous one. */
int LZ4_decompress_fast_withPrefix64k ( const char * source , char * dest , int originalSize )
{
/* LZ4_decompress_fast doesn't validate match offsets,
* and thus serves well with any prefixed dictionary . */
return LZ4_decompress_fast ( source , dest , originalSize ) ;
}
LZ4_FORCE_O2_GCC_PPC64LE
static int LZ4_decompress_safe_withSmallPrefix ( const char * source , char * dest , int compressedSize , int maxOutputSize ,
size_t prefixSize )
{
return LZ4_decompress_generic ( source , dest , compressedSize , maxOutputSize ,
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endOnInputSize , decode_full_block , noDict ,
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( BYTE * ) dest - prefixSize , NULL , 0 ) ;
}
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LZ4_FORCE_O2_GCC_PPC64LE
int LZ4_decompress_safe_forceExtDict ( const char * source , char * dest ,
int compressedSize , int maxOutputSize ,
const void * dictStart , size_t dictSize )
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{
return LZ4_decompress_generic ( source , dest , compressedSize , maxOutputSize ,
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endOnInputSize , decode_full_block , usingExtDict ,
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( BYTE * ) dest , ( const BYTE * ) dictStart , dictSize ) ;
}
LZ4_FORCE_O2_GCC_PPC64LE
static int LZ4_decompress_fast_extDict ( const char * source , char * dest , int originalSize ,
const void * dictStart , size_t dictSize )
{
return LZ4_decompress_generic ( source , dest , 0 , originalSize ,
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endOnOutputSize , decode_full_block , usingExtDict ,
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( BYTE * ) dest , ( const BYTE * ) dictStart , dictSize ) ;
}
/* The "double dictionary" mode, for use with e.g. ring buffers: the first part
* of the dictionary is passed as prefix , and the second via dictStart + dictSize .
* These routines are used only once , in LZ4_decompress_ * _continue ( ) .
*/
LZ4_FORCE_INLINE
int LZ4_decompress_safe_doubleDict ( const char * source , char * dest , int compressedSize , int maxOutputSize ,
size_t prefixSize , const void * dictStart , size_t dictSize )
{
return LZ4_decompress_generic ( source , dest , compressedSize , maxOutputSize ,
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endOnInputSize , decode_full_block , usingExtDict ,
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( BYTE * ) dest - prefixSize , ( const BYTE * ) dictStart , dictSize ) ;
}
LZ4_FORCE_INLINE
int LZ4_decompress_fast_doubleDict ( const char * source , char * dest , int originalSize ,
size_t prefixSize , const void * dictStart , size_t dictSize )
{
return LZ4_decompress_generic ( source , dest , 0 , originalSize ,
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endOnOutputSize , decode_full_block , usingExtDict ,
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( BYTE * ) dest - prefixSize , ( const BYTE * ) dictStart , dictSize ) ;
}
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/*===== streaming decompression functions =====*/
LZ4_streamDecode_t * LZ4_createStreamDecode ( void )
{
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LZ4_streamDecode_t * lz4s = ( LZ4_streamDecode_t * ) ALLOC_AND_ZERO ( sizeof ( LZ4_streamDecode_t ) ) ;
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LZ4_STATIC_ASSERT ( LZ4_STREAMDECODESIZE > = sizeof ( LZ4_streamDecode_t_internal ) ) ; /* A compilation error here means LZ4_STREAMDECODESIZE is not large enough */
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return lz4s ;
}
int LZ4_freeStreamDecode ( LZ4_streamDecode_t * LZ4_stream )
{
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if ( LZ4_stream = = NULL ) return 0 ; /* support free on NULL */
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FREEMEM ( LZ4_stream ) ;
return 0 ;
}
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/*! LZ4_setStreamDecode() :
* Use this function to instruct where to find the dictionary .
* This function is not necessary if previous data is still available where it was decoded .
* Loading a size of 0 is allowed ( same effect as no dictionary ) .
* @ return : 1 if OK , 0 if error
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*/
int LZ4_setStreamDecode ( LZ4_streamDecode_t * LZ4_streamDecode , const char * dictionary , int dictSize )
{
LZ4_streamDecode_t_internal * lz4sd = & LZ4_streamDecode - > internal_donotuse ;
lz4sd - > prefixSize = ( size_t ) dictSize ;
lz4sd - > prefixEnd = ( const BYTE * ) dictionary + dictSize ;
lz4sd - > externalDict = NULL ;
lz4sd - > extDictSize = 0 ;
return 1 ;
}
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/*! LZ4_decoderRingBufferSize() :
* when setting a ring buffer for streaming decompression ( optional scenario ) ,
* provides the minimum size of this ring buffer
* to be compatible with any source respecting maxBlockSize condition .
* Note : in a ring buffer scenario ,
* blocks are presumed decompressed next to each other .
* When not enough space remains for next block ( remainingSize < maxBlockSize ) ,
* decoding resumes from beginning of ring buffer .
* @ return : minimum ring buffer size ,
* or 0 if there is an error ( invalid maxBlockSize ) .
*/
int LZ4_decoderRingBufferSize ( int maxBlockSize )
{
if ( maxBlockSize < 0 ) return 0 ;
if ( maxBlockSize > LZ4_MAX_INPUT_SIZE ) return 0 ;
if ( maxBlockSize < 16 ) maxBlockSize = 16 ;
return LZ4_DECODER_RING_BUFFER_SIZE ( maxBlockSize ) ;
}
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/*
* _continue ( ) :
These decoding functions allow decompression of multiple blocks in " streaming " mode .
Previously decoded blocks must still be available at the memory position where they were decoded .
If it ' s not possible , save the relevant part of decoded data into a safe buffer ,
and indicate where it stands using LZ4_setStreamDecode ( )
*/
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LZ4_FORCE_O2_GCC_PPC64LE
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int LZ4_decompress_safe_continue ( LZ4_streamDecode_t * LZ4_streamDecode , const char * source , char * dest , int compressedSize , int maxOutputSize )
{
LZ4_streamDecode_t_internal * lz4sd = & LZ4_streamDecode - > internal_donotuse ;
int result ;
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if ( lz4sd - > prefixSize = = 0 ) {
/* The first call, no dictionary yet. */
assert ( lz4sd - > extDictSize = = 0 ) ;
result = LZ4_decompress_safe ( source , dest , compressedSize , maxOutputSize ) ;
if ( result < = 0 ) return result ;
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lz4sd - > prefixSize = ( size_t ) result ;
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lz4sd - > prefixEnd = ( BYTE * ) dest + result ;
} else if ( lz4sd - > prefixEnd = = ( BYTE * ) dest ) {
/* They're rolling the current segment. */
if ( lz4sd - > prefixSize > = 64 KB - 1 )
result = LZ4_decompress_safe_withPrefix64k ( source , dest , compressedSize , maxOutputSize ) ;
else if ( lz4sd - > extDictSize = = 0 )
result = LZ4_decompress_safe_withSmallPrefix ( source , dest , compressedSize , maxOutputSize ,
lz4sd - > prefixSize ) ;
else
result = LZ4_decompress_safe_doubleDict ( source , dest , compressedSize , maxOutputSize ,
lz4sd - > prefixSize , lz4sd - > externalDict , lz4sd - > extDictSize ) ;
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if ( result < = 0 ) return result ;
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lz4sd - > prefixSize + = ( size_t ) result ;
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lz4sd - > prefixEnd + = result ;
} else {
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/* The buffer wraps around, or they're switching to another buffer. */
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lz4sd - > extDictSize = lz4sd - > prefixSize ;
lz4sd - > externalDict = lz4sd - > prefixEnd - lz4sd - > extDictSize ;
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result = LZ4_decompress_safe_forceExtDict ( source , dest , compressedSize , maxOutputSize ,
lz4sd - > externalDict , lz4sd - > extDictSize ) ;
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if ( result < = 0 ) return result ;
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lz4sd - > prefixSize = ( size_t ) result ;
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lz4sd - > prefixEnd = ( BYTE * ) dest + result ;
}
return result ;
}
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LZ4_FORCE_O2_GCC_PPC64LE
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int LZ4_decompress_fast_continue ( LZ4_streamDecode_t * LZ4_streamDecode , const char * source , char * dest , int originalSize )
{
LZ4_streamDecode_t_internal * lz4sd = & LZ4_streamDecode - > internal_donotuse ;
int result ;
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assert ( originalSize > = 0 ) ;
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if ( lz4sd - > prefixSize = = 0 ) {
assert ( lz4sd - > extDictSize = = 0 ) ;
result = LZ4_decompress_fast ( source , dest , originalSize ) ;
if ( result < = 0 ) return result ;
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lz4sd - > prefixSize = ( size_t ) originalSize ;
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lz4sd - > prefixEnd = ( BYTE * ) dest + originalSize ;
} else if ( lz4sd - > prefixEnd = = ( BYTE * ) dest ) {
if ( lz4sd - > prefixSize > = 64 KB - 1 | | lz4sd - > extDictSize = = 0 )
result = LZ4_decompress_fast ( source , dest , originalSize ) ;
else
result = LZ4_decompress_fast_doubleDict ( source , dest , originalSize ,
lz4sd - > prefixSize , lz4sd - > externalDict , lz4sd - > extDictSize ) ;
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if ( result < = 0 ) return result ;
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lz4sd - > prefixSize + = ( size_t ) originalSize ;
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lz4sd - > prefixEnd + = originalSize ;
} else {
lz4sd - > extDictSize = lz4sd - > prefixSize ;
lz4sd - > externalDict = lz4sd - > prefixEnd - lz4sd - > extDictSize ;
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result = LZ4_decompress_fast_extDict ( source , dest , originalSize ,
lz4sd - > externalDict , lz4sd - > extDictSize ) ;
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if ( result < = 0 ) return result ;
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lz4sd - > prefixSize = ( size_t ) originalSize ;
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lz4sd - > prefixEnd = ( BYTE * ) dest + originalSize ;
}
return result ;
}
/*
Advanced decoding functions :
* _usingDict ( ) :
These decoding functions work the same as " _continue " ones ,
the dictionary must be explicitly provided within parameters
*/
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int LZ4_decompress_safe_usingDict ( const char * source , char * dest , int compressedSize , int maxOutputSize , const char * dictStart , int dictSize )
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{
if ( dictSize = = 0 )
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return LZ4_decompress_safe ( source , dest , compressedSize , maxOutputSize ) ;
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if ( dictStart + dictSize = = dest ) {
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if ( dictSize > = 64 KB - 1 )
return LZ4_decompress_safe_withPrefix64k ( source , dest , compressedSize , maxOutputSize ) ;
return LZ4_decompress_safe_withSmallPrefix ( source , dest , compressedSize , maxOutputSize , dictSize ) ;
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}
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return LZ4_decompress_safe_forceExtDict ( source , dest , compressedSize , maxOutputSize , dictStart , dictSize ) ;
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}
int LZ4_decompress_fast_usingDict ( const char * source , char * dest , int originalSize , const char * dictStart , int dictSize )
{
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if ( dictSize = = 0 | | dictStart + dictSize = = dest )
return LZ4_decompress_fast ( source , dest , originalSize ) ;
return LZ4_decompress_fast_extDict ( source , dest , originalSize , dictStart , dictSize ) ;
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}
/*=*************************************************
* Obsolete Functions
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* obsolete compression functions */
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int LZ4_compress_limitedOutput ( const char * source , char * dest , int inputSize , int maxOutputSize )
{
return LZ4_compress_default ( source , dest , inputSize , maxOutputSize ) ;
}
int LZ4_compress ( const char * source , char * dest , int inputSize )
{
return LZ4_compress_default ( source , dest , inputSize , LZ4_compressBound ( inputSize ) ) ;
}
int LZ4_compress_limitedOutput_withState ( void * state , const char * src , char * dst , int srcSize , int dstSize )
{
return LZ4_compress_fast_extState ( state , src , dst , srcSize , dstSize , 1 ) ;
}
int LZ4_compress_withState ( void * state , const char * src , char * dst , int srcSize )
{
return LZ4_compress_fast_extState ( state , src , dst , srcSize , LZ4_compressBound ( srcSize ) , 1 ) ;
}
int LZ4_compress_limitedOutput_continue ( LZ4_stream_t * LZ4_stream , const char * src , char * dst , int srcSize , int dstCapacity )
{
return LZ4_compress_fast_continue ( LZ4_stream , src , dst , srcSize , dstCapacity , 1 ) ;
}
int LZ4_compress_continue ( LZ4_stream_t * LZ4_stream , const char * source , char * dest , int inputSize )
{
return LZ4_compress_fast_continue ( LZ4_stream , source , dest , inputSize , LZ4_compressBound ( inputSize ) , 1 ) ;
}
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/*
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These decompression functions are deprecated and should no longer be used .
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They are only provided here for compatibility with older user programs .
- LZ4_uncompress is totally equivalent to LZ4_decompress_fast
- LZ4_uncompress_unknownOutputSize is totally equivalent to LZ4_decompress_safe
*/
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int LZ4_uncompress ( const char * source , char * dest , int outputSize )
{
return LZ4_decompress_fast ( source , dest , outputSize ) ;
}
int LZ4_uncompress_unknownOutputSize ( const char * source , char * dest , int isize , int maxOutputSize )
{
return LZ4_decompress_safe ( source , dest , isize , maxOutputSize ) ;
}
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/* Obsolete Streaming functions */
int LZ4_sizeofStreamState ( ) { return LZ4_STREAMSIZE ; }
int LZ4_resetStreamState ( void * state , char * inputBuffer )
{
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( void ) inputBuffer ;
LZ4_resetStream ( ( LZ4_stream_t * ) state ) ;
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return 0 ;
}
void * LZ4_create ( char * inputBuffer )
{
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( void ) inputBuffer ;
return LZ4_createStream ( ) ;
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}
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char * LZ4_slideInputBuffer ( void * state )
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{
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/* avoid const char * -> char * conversion warning */
return ( char * ) ( uptrval ) ( ( LZ4_stream_t * ) state ) - > internal_donotuse . dictionary ;
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}
# endif /* LZ4_COMMONDEFS_ONLY */
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}