1464 lines
56 KiB
C
1464 lines
56 KiB
C
/*
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LZ4 - Fast LZ compression algorithm
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Copyright (C) 2011-2016, Yann Collet.
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BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are
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met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above
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copyright notice, this list of conditions and the following disclaimer
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in the documentation and/or other materials provided with the
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distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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You can contact the author at :
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- LZ4 homepage : http://www.lz4.org
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- LZ4 source repository : https://github.com/lz4/lz4
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*/
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/*-************************************
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* Tuning parameters
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**************************************/
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/*
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* HEAPMODE :
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* Select how default compression functions will allocate memory for their hash table,
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* in memory stack (0:default, fastest), or in memory heap (1:requires malloc()).
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*/
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#ifndef HEAPMODE
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# define HEAPMODE 0
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#endif
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/*
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* ACCELERATION_DEFAULT :
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* Select "acceleration" for LZ4_compress_fast() when parameter value <= 0
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*/
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#define ACCELERATION_DEFAULT 1
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/*-************************************
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* CPU Feature Detection
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**************************************/
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/* LZ4_FORCE_MEMORY_ACCESS
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* By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
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* Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
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* The below switch allow to select different access method for improved performance.
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* Method 0 (default) : use `memcpy()`. Safe and portable.
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* Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
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* This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
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* Method 2 : direct access. This method is portable but violate C standard.
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* It can generate buggy code on targets which generate assembly depending on alignment.
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* But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
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* See https://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
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* Prefer these methods in priority order (0 > 1 > 2)
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*/
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#ifndef LZ4_FORCE_MEMORY_ACCESS /* can be defined externally, on command line for example */
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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) || \
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(defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) ))
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# define LZ4_FORCE_MEMORY_ACCESS 1
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# endif
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#endif
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/*
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* LZ4_FORCE_SW_BITCOUNT
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* Define this parameter if your target system or compiler does not support hardware bit count
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*/
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#if defined(_MSC_VER) && defined(_WIN32_WCE) /* Visual Studio for Windows CE does not support Hardware bit count */
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# define LZ4_FORCE_SW_BITCOUNT
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#endif
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/*-************************************
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* Dependency
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**************************************/
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#include "lz4.h"
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/* see also "memory routines" below */
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/*-************************************
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* Compiler Options
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**************************************/
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#ifdef _MSC_VER /* Visual Studio */
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# define FORCE_INLINE static __forceinline
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# include <intrin.h>
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# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
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# pragma warning(disable : 4293) /* disable: C4293: too large shift (32-bits) */
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#else
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# if defined(__GNUC__) || defined(__clang__)
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# define FORCE_INLINE static inline __attribute__((always_inline))
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# elif defined(__cplusplus) || (defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
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# define FORCE_INLINE static inline
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# else
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# define FORCE_INLINE static
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# endif
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#endif /* _MSC_VER */
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#if (defined(__GNUC__) && (__GNUC__ >= 3)) || (defined(__INTEL_COMPILER) && (__INTEL_COMPILER >= 800)) || defined(__clang__)
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# define expect(expr,value) (__builtin_expect ((expr),(value)) )
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#else
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# define expect(expr,value) (expr)
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#endif
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#define likely(expr) expect((expr) != 0, 1)
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#define unlikely(expr) expect((expr) != 0, 0)
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/*-************************************
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* Memory routines
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**************************************/
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#include <stdlib.h> /* malloc, calloc, free */
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#define ALLOCATOR(n,s) calloc(n,s)
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#define FREEMEM free
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#include <string.h> /* memset, memcpy */
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#define MEM_INIT memset
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/*-************************************
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* Basic Types
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**************************************/
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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;
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typedef uint16_t U16;
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typedef uint32_t U32;
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typedef int32_t S32;
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typedef uint64_t U64;
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typedef uintptr_t uptrval;
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#else
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typedef unsigned char BYTE;
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typedef unsigned short U16;
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typedef unsigned int U32;
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typedef signed int S32;
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typedef unsigned long long U64;
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typedef size_t uptrval; /* generally true, except OpenVMS-64 */
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#endif
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#if defined(__x86_64__)
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typedef U64 reg_t; /* 64-bits in x32 mode */
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#else
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typedef size_t reg_t; /* 32-bits in x32 mode */
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#endif
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/*-************************************
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* Reading and writing into memory
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**************************************/
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static unsigned LZ4_isLittleEndian(void)
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{
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const union { U32 u; BYTE c[4]; } one = { 1 }; /* don't use static : performance detrimental */
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return one.c[0];
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}
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#if defined(LZ4_FORCE_MEMORY_ACCESS) && (LZ4_FORCE_MEMORY_ACCESS==2)
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/* lie to the compiler about data alignment; use with caution */
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static U16 LZ4_read16(const void* memPtr) { return *(const U16*) memPtr; }
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static U32 LZ4_read32(const void* memPtr) { return *(const U32*) memPtr; }
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static reg_t LZ4_read_ARCH(const void* memPtr) { return *(const reg_t*) memPtr; }
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static void LZ4_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; }
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static void LZ4_write32(void* memPtr, U32 value) { *(U32*)memPtr = value; }
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#elif defined(LZ4_FORCE_MEMORY_ACCESS) && (LZ4_FORCE_MEMORY_ACCESS==1)
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/* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
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/* currently only defined for gcc and icc */
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typedef union { U16 u16; U32 u32; reg_t uArch; } __attribute__((packed)) unalign;
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static U16 LZ4_read16(const void* ptr) { return ((const unalign*)ptr)->u16; }
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static U32 LZ4_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
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static reg_t LZ4_read_ARCH(const void* ptr) { return ((const unalign*)ptr)->uArch; }
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static void LZ4_write16(void* memPtr, U16 value) { ((unalign*)memPtr)->u16 = value; }
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static void LZ4_write32(void* memPtr, U32 value) { ((unalign*)memPtr)->u32 = value; }
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#else /* safe and portable access through memcpy() */
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static U16 LZ4_read16(const void* memPtr)
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{
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U16 val; memcpy(&val, memPtr, sizeof(val)); return val;
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}
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static U32 LZ4_read32(const void* memPtr)
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{
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U32 val; memcpy(&val, memPtr, sizeof(val)); return val;
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}
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static reg_t LZ4_read_ARCH(const void* memPtr)
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{
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reg_t val; memcpy(&val, memPtr, sizeof(val)); return val;
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}
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static void LZ4_write16(void* memPtr, U16 value)
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{
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memcpy(memPtr, &value, sizeof(value));
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}
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static void LZ4_write32(void* memPtr, U32 value)
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{
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memcpy(memPtr, &value, sizeof(value));
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}
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#endif /* LZ4_FORCE_MEMORY_ACCESS */
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static U16 LZ4_readLE16(const void* memPtr)
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{
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if (LZ4_isLittleEndian()) {
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return LZ4_read16(memPtr);
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} else {
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const BYTE* p = (const BYTE*)memPtr;
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return (U16)((U16)p[0] + (p[1]<<8));
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}
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}
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static void LZ4_writeLE16(void* memPtr, U16 value)
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{
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if (LZ4_isLittleEndian()) {
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LZ4_write16(memPtr, value);
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} else {
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BYTE* p = (BYTE*)memPtr;
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p[0] = (BYTE) value;
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p[1] = (BYTE)(value>>8);
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}
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}
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static void LZ4_copy8(void* dst, const void* src)
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{
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memcpy(dst,src,8);
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}
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/* customized variant of memcpy, which can overwrite up to 8 bytes beyond dstEnd */
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static void LZ4_wildCopy(void* dstPtr, const void* srcPtr, void* dstEnd)
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{
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BYTE* d = (BYTE*)dstPtr;
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const BYTE* s = (const BYTE*)srcPtr;
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BYTE* const e = (BYTE*)dstEnd;
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do { LZ4_copy8(d,s); d+=8; s+=8; } while (d<e);
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}
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/*-************************************
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* Common Constants
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**************************************/
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#define MINMATCH 4
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#define WILDCOPYLENGTH 8
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#define LASTLITERALS 5
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#define MFLIMIT (WILDCOPYLENGTH+MINMATCH)
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static const int LZ4_minLength = (MFLIMIT+1);
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#define KB *(1 <<10)
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#define MB *(1 <<20)
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#define GB *(1U<<30)
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#define MAXD_LOG 16
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#define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
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#define ML_BITS 4
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#define ML_MASK ((1U<<ML_BITS)-1)
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#define RUN_BITS (8-ML_BITS)
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#define RUN_MASK ((1U<<RUN_BITS)-1)
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/*-************************************
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* Common Utils
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**************************************/
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#define LZ4_STATIC_ASSERT(c) { enum { LZ4_static_assert = 1/(int)(!!(c)) }; } /* use only *after* variable declarations */
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/*-************************************
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* Common functions
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**************************************/
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static unsigned LZ4_NbCommonBytes (register reg_t val)
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{
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if (LZ4_isLittleEndian()) {
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if (sizeof(val)==8) {
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# if defined(_MSC_VER) && defined(_WIN64) && !defined(LZ4_FORCE_SW_BITCOUNT)
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unsigned long r = 0;
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_BitScanForward64( &r, (U64)val );
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return (int)(r>>3);
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# elif (defined(__clang__) || (defined(__GNUC__) && (__GNUC__>=3))) && !defined(LZ4_FORCE_SW_BITCOUNT)
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return (__builtin_ctzll((U64)val) >> 3);
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# 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];
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# endif
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} else /* 32 bits */ {
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# if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
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unsigned long r;
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_BitScanForward( &r, (U32)val );
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return (int)(r>>3);
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# elif (defined(__clang__) || (defined(__GNUC__) && (__GNUC__>=3))) && !defined(LZ4_FORCE_SW_BITCOUNT)
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return (__builtin_ctz((U32)val) >> 3);
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# 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];
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# endif
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}
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} else /* Big Endian CPU */ {
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if (sizeof(val)==8) {
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# if defined(_MSC_VER) && defined(_WIN64) && !defined(LZ4_FORCE_SW_BITCOUNT)
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unsigned long r = 0;
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_BitScanReverse64( &r, val );
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return (unsigned)(r>>3);
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# elif (defined(__clang__) || (defined(__GNUC__) && (__GNUC__>=3))) && !defined(LZ4_FORCE_SW_BITCOUNT)
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return (__builtin_clzll((U64)val) >> 3);
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# else
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unsigned r;
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if (!(val>>32)) { r=4; } else { r=0; val>>=32; }
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if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
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r += (!val);
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return r;
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# endif
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} else /* 32 bits */ {
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# if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
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unsigned long r = 0;
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_BitScanReverse( &r, (unsigned long)val );
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return (unsigned)(r>>3);
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# elif (defined(__clang__) || (defined(__GNUC__) && (__GNUC__>=3))) && !defined(LZ4_FORCE_SW_BITCOUNT)
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return (__builtin_clz((U32)val) >> 3);
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# else
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unsigned r;
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if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
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r += (!val);
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return r;
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# endif
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}
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}
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}
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#define STEPSIZE sizeof(reg_t)
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static unsigned LZ4_count(const BYTE* pIn, const BYTE* pMatch, const BYTE* pInLimit)
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{
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const BYTE* const pStart = pIn;
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while (likely(pIn<pInLimit-(STEPSIZE-1))) {
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reg_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn);
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if (!diff) { pIn+=STEPSIZE; pMatch+=STEPSIZE; continue; }
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pIn += LZ4_NbCommonBytes(diff);
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return (unsigned)(pIn - pStart);
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}
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if ((STEPSIZE==8) && (pIn<(pInLimit-3)) && (LZ4_read32(pMatch) == LZ4_read32(pIn))) { pIn+=4; pMatch+=4; }
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if ((pIn<(pInLimit-1)) && (LZ4_read16(pMatch) == LZ4_read16(pIn))) { pIn+=2; pMatch+=2; }
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if ((pIn<pInLimit) && (*pMatch == *pIn)) pIn++;
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return (unsigned)(pIn - pStart);
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}
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#ifndef LZ4_COMMONDEFS_ONLY
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/*-************************************
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* Local Constants
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**************************************/
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static const int LZ4_64Klimit = ((64 KB) + (MFLIMIT-1));
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static const U32 LZ4_skipTrigger = 6; /* Increase this value ==> compression run slower on incompressible data */
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/*-************************************
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* Local Structures and types
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**************************************/
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typedef enum { notLimited = 0, limitedOutput = 1 } limitedOutput_directive;
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typedef enum { byPtr, byU32, byU16 } tableType_t;
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typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
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typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive;
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typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
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typedef enum { full = 0, partial = 1 } earlyEnd_directive;
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/*-************************************
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* Local Utils
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**************************************/
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int LZ4_versionNumber (void) { return LZ4_VERSION_NUMBER; }
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const char* LZ4_versionString(void) { return LZ4_VERSION_STRING; }
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int LZ4_compressBound(int isize) { return LZ4_COMPRESSBOUND(isize); }
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int LZ4_sizeofState() { return LZ4_STREAMSIZE; }
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/*-******************************
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* Compression functions
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********************************/
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static U32 LZ4_hash4(U32 sequence, tableType_t const tableType)
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{
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if (tableType == byU16)
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return ((sequence * 2654435761U) >> ((MINMATCH*8)-(LZ4_HASHLOG+1)));
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else
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return ((sequence * 2654435761U) >> ((MINMATCH*8)-LZ4_HASHLOG));
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}
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static U32 LZ4_hash5(U64 sequence, tableType_t const tableType)
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{
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static const U64 prime5bytes = 889523592379ULL;
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static const U64 prime8bytes = 11400714785074694791ULL;
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const U32 hashLog = (tableType == byU16) ? LZ4_HASHLOG+1 : LZ4_HASHLOG;
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if (LZ4_isLittleEndian())
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return (U32)(((sequence << 24) * prime5bytes) >> (64 - hashLog));
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else
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return (U32)(((sequence >> 24) * prime8bytes) >> (64 - hashLog));
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}
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FORCE_INLINE U32 LZ4_hashPosition(const void* const p, tableType_t const tableType)
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{
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if ((sizeof(reg_t)==8) && (tableType != byU16)) return LZ4_hash5(LZ4_read_ARCH(p), tableType);
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return LZ4_hash4(LZ4_read32(p), tableType);
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}
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static void LZ4_putPositionOnHash(const BYTE* p, U32 h, void* tableBase, tableType_t const tableType, const BYTE* srcBase)
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{
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switch (tableType)
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{
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case byPtr: { const BYTE** hashTable = (const BYTE**)tableBase; hashTable[h] = p; return; }
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case byU32: { U32* hashTable = (U32*) tableBase; hashTable[h] = (U32)(p-srcBase); return; }
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case byU16: { U16* hashTable = (U16*) tableBase; hashTable[h] = (U16)(p-srcBase); return; }
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}
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}
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FORCE_INLINE void LZ4_putPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
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{
|
|
U32 const h = LZ4_hashPosition(p, tableType);
|
|
LZ4_putPositionOnHash(p, h, tableBase, tableType, srcBase);
|
|
}
|
|
|
|
static const BYTE* LZ4_getPositionOnHash(U32 h, void* tableBase, tableType_t tableType, const BYTE* srcBase)
|
|
{
|
|
if (tableType == byPtr) { const BYTE** hashTable = (const BYTE**) tableBase; return hashTable[h]; }
|
|
if (tableType == byU32) { const U32* const hashTable = (U32*) tableBase; return hashTable[h] + srcBase; }
|
|
{ const U16* const hashTable = (U16*) tableBase; return hashTable[h] + srcBase; } /* default, to ensure a return */
|
|
}
|
|
|
|
FORCE_INLINE const BYTE* LZ4_getPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
|
|
{
|
|
U32 const h = LZ4_hashPosition(p, tableType);
|
|
return LZ4_getPositionOnHash(h, tableBase, tableType, srcBase);
|
|
}
|
|
|
|
|
|
/** LZ4_compress_generic() :
|
|
inlined, to ensure branches are decided at compilation time */
|
|
FORCE_INLINE int LZ4_compress_generic(
|
|
LZ4_stream_t_internal* const cctx,
|
|
const char* const source,
|
|
char* const dest,
|
|
const int inputSize,
|
|
const int maxOutputSize,
|
|
const limitedOutput_directive outputLimited,
|
|
const tableType_t tableType,
|
|
const dict_directive dict,
|
|
const dictIssue_directive dictIssue,
|
|
const U32 acceleration)
|
|
{
|
|
const BYTE* ip = (const BYTE*) source;
|
|
const BYTE* base;
|
|
const BYTE* lowLimit;
|
|
const BYTE* const lowRefLimit = ip - cctx->dictSize;
|
|
const BYTE* const dictionary = cctx->dictionary;
|
|
const BYTE* const dictEnd = dictionary + cctx->dictSize;
|
|
const ptrdiff_t dictDelta = dictEnd - (const BYTE*)source;
|
|
const BYTE* anchor = (const BYTE*) source;
|
|
const BYTE* const iend = ip + inputSize;
|
|
const BYTE* const mflimit = iend - MFLIMIT;
|
|
const BYTE* const matchlimit = iend - LASTLITERALS;
|
|
|
|
BYTE* op = (BYTE*) dest;
|
|
BYTE* const olimit = op + maxOutputSize;
|
|
|
|
U32 forwardH;
|
|
|
|
/* Init conditions */
|
|
if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported inputSize, too large (or negative) */
|
|
switch(dict)
|
|
{
|
|
case noDict:
|
|
default:
|
|
base = (const BYTE*)source;
|
|
lowLimit = (const BYTE*)source;
|
|
break;
|
|
case withPrefix64k:
|
|
base = (const BYTE*)source - cctx->currentOffset;
|
|
lowLimit = (const BYTE*)source - cctx->dictSize;
|
|
break;
|
|
case usingExtDict:
|
|
base = (const BYTE*)source - cctx->currentOffset;
|
|
lowLimit = (const BYTE*)source;
|
|
break;
|
|
}
|
|
if ((tableType == byU16) && (inputSize>=LZ4_64Klimit)) return 0; /* Size too large (not within 64K limit) */
|
|
if (inputSize<LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */
|
|
|
|
/* First Byte */
|
|
LZ4_putPosition(ip, cctx->hashTable, tableType, base);
|
|
ip++; forwardH = LZ4_hashPosition(ip, tableType);
|
|
|
|
/* Main Loop */
|
|
for ( ; ; ) {
|
|
ptrdiff_t refDelta = 0;
|
|
const BYTE* match;
|
|
BYTE* token;
|
|
|
|
/* Find a match */
|
|
{ const BYTE* forwardIp = ip;
|
|
unsigned step = 1;
|
|
unsigned searchMatchNb = acceleration << LZ4_skipTrigger;
|
|
do {
|
|
U32 const h = forwardH;
|
|
ip = forwardIp;
|
|
forwardIp += step;
|
|
step = (searchMatchNb++ >> LZ4_skipTrigger);
|
|
|
|
if (unlikely(forwardIp > mflimit)) goto _last_literals;
|
|
|
|
match = LZ4_getPositionOnHash(h, cctx->hashTable, tableType, base);
|
|
if (dict==usingExtDict) {
|
|
if (match < (const BYTE*)source) {
|
|
refDelta = dictDelta;
|
|
lowLimit = dictionary;
|
|
} else {
|
|
refDelta = 0;
|
|
lowLimit = (const BYTE*)source;
|
|
} }
|
|
forwardH = LZ4_hashPosition(forwardIp, tableType);
|
|
LZ4_putPositionOnHash(ip, h, cctx->hashTable, tableType, base);
|
|
|
|
} while ( ((dictIssue==dictSmall) ? (match < lowRefLimit) : 0)
|
|
|| ((tableType==byU16) ? 0 : (match + MAX_DISTANCE < ip))
|
|
|| (LZ4_read32(match+refDelta) != LZ4_read32(ip)) );
|
|
}
|
|
|
|
/* Catch up */
|
|
while (((ip>anchor) & (match+refDelta > lowLimit)) && (unlikely(ip[-1]==match[refDelta-1]))) { ip--; match--; }
|
|
|
|
/* Encode Literals */
|
|
{ unsigned const litLength = (unsigned)(ip - anchor);
|
|
token = op++;
|
|
if ((outputLimited) && /* Check output buffer overflow */
|
|
(unlikely(op + litLength + (2 + 1 + LASTLITERALS) + (litLength/255) > olimit)))
|
|
return 0;
|
|
if (litLength >= RUN_MASK) {
|
|
int len = (int)litLength-RUN_MASK;
|
|
*token = (RUN_MASK<<ML_BITS);
|
|
for(; len >= 255 ; len-=255) *op++ = 255;
|
|
*op++ = (BYTE)len;
|
|
}
|
|
else *token = (BYTE)(litLength<<ML_BITS);
|
|
|
|
/* Copy Literals */
|
|
LZ4_wildCopy(op, anchor, op+litLength);
|
|
op+=litLength;
|
|
}
|
|
|
|
_next_match:
|
|
/* Encode Offset */
|
|
LZ4_writeLE16(op, (U16)(ip-match)); op+=2;
|
|
|
|
/* Encode MatchLength */
|
|
{ unsigned matchCode;
|
|
|
|
if ((dict==usingExtDict) && (lowLimit==dictionary)) {
|
|
const BYTE* limit;
|
|
match += refDelta;
|
|
limit = ip + (dictEnd-match);
|
|
if (limit > matchlimit) limit = matchlimit;
|
|
matchCode = LZ4_count(ip+MINMATCH, match+MINMATCH, limit);
|
|
ip += MINMATCH + matchCode;
|
|
if (ip==limit) {
|
|
unsigned const more = LZ4_count(ip, (const BYTE*)source, matchlimit);
|
|
matchCode += more;
|
|
ip += more;
|
|
}
|
|
} else {
|
|
matchCode = LZ4_count(ip+MINMATCH, match+MINMATCH, matchlimit);
|
|
ip += MINMATCH + matchCode;
|
|
}
|
|
|
|
if ( outputLimited && /* Check output buffer overflow */
|
|
(unlikely(op + (1 + LASTLITERALS) + (matchCode>>8) > olimit)) )
|
|
return 0;
|
|
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 */
|
|
if (ip > mflimit) break;
|
|
|
|
/* Fill table */
|
|
LZ4_putPosition(ip-2, cctx->hashTable, tableType, base);
|
|
|
|
/* Test next position */
|
|
match = LZ4_getPosition(ip, cctx->hashTable, tableType, base);
|
|
if (dict==usingExtDict) {
|
|
if (match < (const BYTE*)source) {
|
|
refDelta = dictDelta;
|
|
lowLimit = dictionary;
|
|
} else {
|
|
refDelta = 0;
|
|
lowLimit = (const BYTE*)source;
|
|
} }
|
|
LZ4_putPosition(ip, cctx->hashTable, tableType, base);
|
|
if ( ((dictIssue==dictSmall) ? (match>=lowRefLimit) : 1)
|
|
&& (match+MAX_DISTANCE>=ip)
|
|
&& (LZ4_read32(match+refDelta)==LZ4_read32(ip)) )
|
|
{ token=op++; *token=0; goto _next_match; }
|
|
|
|
/* Prepare next loop */
|
|
forwardH = LZ4_hashPosition(++ip, tableType);
|
|
}
|
|
|
|
_last_literals:
|
|
/* Encode Last Literals */
|
|
{ size_t const lastRun = (size_t)(iend - anchor);
|
|
if ( (outputLimited) && /* Check output buffer overflow */
|
|
((op - (BYTE*)dest) + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > (U32)maxOutputSize) )
|
|
return 0;
|
|
if (lastRun >= RUN_MASK) {
|
|
size_t accumulator = lastRun - RUN_MASK;
|
|
*op++ = RUN_MASK << ML_BITS;
|
|
for(; accumulator >= 255 ; accumulator-=255) *op++ = 255;
|
|
*op++ = (BYTE) accumulator;
|
|
} else {
|
|
*op++ = (BYTE)(lastRun<<ML_BITS);
|
|
}
|
|
memcpy(op, anchor, lastRun);
|
|
op += lastRun;
|
|
}
|
|
|
|
/* End */
|
|
return (int) (((char*)op)-dest);
|
|
}
|
|
|
|
|
|
int LZ4_compress_fast_extState(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration)
|
|
{
|
|
LZ4_stream_t_internal* ctx = &((LZ4_stream_t*)state)->internal_donotuse;
|
|
LZ4_resetStream((LZ4_stream_t*)state);
|
|
if (acceleration < 1) acceleration = ACCELERATION_DEFAULT;
|
|
|
|
if (maxOutputSize >= LZ4_compressBound(inputSize)) {
|
|
if (inputSize < LZ4_64Klimit)
|
|
return LZ4_compress_generic(ctx, source, dest, inputSize, 0, notLimited, byU16, noDict, noDictIssue, acceleration);
|
|
else
|
|
return LZ4_compress_generic(ctx, source, dest, inputSize, 0, notLimited, (sizeof(void*)==8) ? byU32 : byPtr, noDict, noDictIssue, acceleration);
|
|
} else {
|
|
if (inputSize < LZ4_64Klimit)
|
|
return LZ4_compress_generic(ctx, source, dest, inputSize, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue, acceleration);
|
|
else
|
|
return LZ4_compress_generic(ctx, source, dest, inputSize, maxOutputSize, limitedOutput, (sizeof(void*)==8) ? byU32 : byPtr, noDict, noDictIssue, acceleration);
|
|
}
|
|
}
|
|
|
|
|
|
int LZ4_compress_fast(const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration)
|
|
{
|
|
#if (HEAPMODE)
|
|
void* ctxPtr = ALLOCATOR(1, sizeof(LZ4_stream_t)); /* malloc-calloc always properly aligned */
|
|
#else
|
|
LZ4_stream_t ctx;
|
|
void* const ctxPtr = &ctx;
|
|
#endif
|
|
|
|
int const result = LZ4_compress_fast_extState(ctxPtr, source, dest, inputSize, maxOutputSize, acceleration);
|
|
|
|
#if (HEAPMODE)
|
|
FREEMEM(ctxPtr);
|
|
#endif
|
|
return result;
|
|
}
|
|
|
|
|
|
int LZ4_compress_default(const char* source, char* dest, int inputSize, int maxOutputSize)
|
|
{
|
|
return LZ4_compress_fast(source, dest, inputSize, maxOutputSize, 1);
|
|
}
|
|
|
|
|
|
/* hidden debug function */
|
|
/* strangely enough, gcc generates faster code when this function is uncommented, even if unused */
|
|
int LZ4_compress_fast_force(const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration)
|
|
{
|
|
LZ4_stream_t ctx;
|
|
LZ4_resetStream(&ctx);
|
|
|
|
if (inputSize < LZ4_64Klimit)
|
|
return LZ4_compress_generic(&ctx.internal_donotuse, source, dest, inputSize, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue, acceleration);
|
|
else
|
|
return LZ4_compress_generic(&ctx.internal_donotuse, source, dest, inputSize, maxOutputSize, limitedOutput, sizeof(void*)==8 ? byU32 : byPtr, noDict, noDictIssue, acceleration);
|
|
}
|
|
|
|
|
|
/*-******************************
|
|
* *_destSize() variant
|
|
********************************/
|
|
|
|
static int LZ4_compress_destSize_generic(
|
|
LZ4_stream_t_internal* const ctx,
|
|
const char* const src,
|
|
char* const dst,
|
|
int* const srcSizePtr,
|
|
const int targetDstSize,
|
|
const tableType_t tableType)
|
|
{
|
|
const BYTE* ip = (const BYTE*) src;
|
|
const BYTE* base = (const BYTE*) src;
|
|
const BYTE* lowLimit = (const BYTE*) src;
|
|
const BYTE* anchor = ip;
|
|
const BYTE* const iend = ip + *srcSizePtr;
|
|
const BYTE* const mflimit = iend - MFLIMIT;
|
|
const BYTE* const matchlimit = iend - LASTLITERALS;
|
|
|
|
BYTE* op = (BYTE*) dst;
|
|
BYTE* const oend = op + targetDstSize;
|
|
BYTE* const oMaxLit = op + targetDstSize - 2 /* offset */ - 8 /* because 8+MINMATCH==MFLIMIT */ - 1 /* token */;
|
|
BYTE* const oMaxMatch = op + targetDstSize - (LASTLITERALS + 1 /* token */);
|
|
BYTE* const oMaxSeq = oMaxLit - 1 /* token */;
|
|
|
|
U32 forwardH;
|
|
|
|
|
|
/* Init conditions */
|
|
if (targetDstSize < 1) return 0; /* Impossible to store anything */
|
|
if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size, too large (or negative) */
|
|
if ((tableType == byU16) && (*srcSizePtr>=LZ4_64Klimit)) return 0; /* Size too large (not within 64K limit) */
|
|
if (*srcSizePtr<LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */
|
|
|
|
/* First Byte */
|
|
*srcSizePtr = 0;
|
|
LZ4_putPosition(ip, ctx->hashTable, tableType, base);
|
|
ip++; forwardH = LZ4_hashPosition(ip, tableType);
|
|
|
|
/* Main Loop */
|
|
for ( ; ; ) {
|
|
const BYTE* match;
|
|
BYTE* token;
|
|
|
|
/* Find a match */
|
|
{ const BYTE* forwardIp = ip;
|
|
unsigned step = 1;
|
|
unsigned searchMatchNb = 1 << LZ4_skipTrigger;
|
|
|
|
do {
|
|
U32 h = forwardH;
|
|
ip = forwardIp;
|
|
forwardIp += step;
|
|
step = (searchMatchNb++ >> LZ4_skipTrigger);
|
|
|
|
if (unlikely(forwardIp > mflimit)) goto _last_literals;
|
|
|
|
match = LZ4_getPositionOnHash(h, ctx->hashTable, tableType, base);
|
|
forwardH = LZ4_hashPosition(forwardIp, tableType);
|
|
LZ4_putPositionOnHash(ip, h, ctx->hashTable, tableType, base);
|
|
|
|
} while ( ((tableType==byU16) ? 0 : (match + MAX_DISTANCE < ip))
|
|
|| (LZ4_read32(match) != LZ4_read32(ip)) );
|
|
}
|
|
|
|
/* Catch up */
|
|
while ((ip>anchor) && (match > lowLimit) && (unlikely(ip[-1]==match[-1]))) { ip--; match--; }
|
|
|
|
/* Encode Literal length */
|
|
{ unsigned litLength = (unsigned)(ip - anchor);
|
|
token = op++;
|
|
if (op + ((litLength+240)/255) + litLength > oMaxLit) {
|
|
/* Not enough space for a last match */
|
|
op--;
|
|
goto _last_literals;
|
|
}
|
|
if (litLength>=RUN_MASK) {
|
|
unsigned len = litLength - RUN_MASK;
|
|
*token=(RUN_MASK<<ML_BITS);
|
|
for(; len >= 255 ; len-=255) *op++ = 255;
|
|
*op++ = (BYTE)len;
|
|
}
|
|
else *token = (BYTE)(litLength<<ML_BITS);
|
|
|
|
/* Copy Literals */
|
|
LZ4_wildCopy(op, anchor, op+litLength);
|
|
op += litLength;
|
|
}
|
|
|
|
_next_match:
|
|
/* Encode Offset */
|
|
LZ4_writeLE16(op, (U16)(ip-match)); op+=2;
|
|
|
|
/* Encode MatchLength */
|
|
{ size_t matchLength = LZ4_count(ip+MINMATCH, match+MINMATCH, matchlimit);
|
|
|
|
if (op + ((matchLength+240)/255) > oMaxMatch) {
|
|
/* Match description too long : reduce it */
|
|
matchLength = (15-1) + (oMaxMatch-op) * 255;
|
|
}
|
|
ip += MINMATCH + matchLength;
|
|
|
|
if (matchLength>=ML_MASK) {
|
|
*token += ML_MASK;
|
|
matchLength -= ML_MASK;
|
|
while (matchLength >= 255) { matchLength-=255; *op++ = 255; }
|
|
*op++ = (BYTE)matchLength;
|
|
}
|
|
else *token += (BYTE)(matchLength);
|
|
}
|
|
|
|
anchor = ip;
|
|
|
|
/* Test end of block */
|
|
if (ip > mflimit) break;
|
|
if (op > oMaxSeq) break;
|
|
|
|
/* Fill table */
|
|
LZ4_putPosition(ip-2, ctx->hashTable, tableType, base);
|
|
|
|
/* Test next position */
|
|
match = LZ4_getPosition(ip, ctx->hashTable, tableType, base);
|
|
LZ4_putPosition(ip, ctx->hashTable, tableType, base);
|
|
if ( (match+MAX_DISTANCE>=ip)
|
|
&& (LZ4_read32(match)==LZ4_read32(ip)) )
|
|
{ token=op++; *token=0; goto _next_match; }
|
|
|
|
/* Prepare next loop */
|
|
forwardH = LZ4_hashPosition(++ip, tableType);
|
|
}
|
|
|
|
_last_literals:
|
|
/* Encode Last Literals */
|
|
{ size_t lastRunSize = (size_t)(iend - anchor);
|
|
if (op + 1 /* token */ + ((lastRunSize+240)/255) /* litLength */ + lastRunSize /* literals */ > oend) {
|
|
/* adapt lastRunSize to fill 'dst' */
|
|
lastRunSize = (oend-op) - 1;
|
|
lastRunSize -= (lastRunSize+240)/255;
|
|
}
|
|
ip = anchor + lastRunSize;
|
|
|
|
if (lastRunSize >= RUN_MASK) {
|
|
size_t accumulator = lastRunSize - RUN_MASK;
|
|
*op++ = RUN_MASK << ML_BITS;
|
|
for(; accumulator >= 255 ; accumulator-=255) *op++ = 255;
|
|
*op++ = (BYTE) accumulator;
|
|
} else {
|
|
*op++ = (BYTE)(lastRunSize<<ML_BITS);
|
|
}
|
|
memcpy(op, anchor, lastRunSize);
|
|
op += lastRunSize;
|
|
}
|
|
|
|
/* End */
|
|
*srcSizePtr = (int) (((const char*)ip)-src);
|
|
return (int) (((char*)op)-dst);
|
|
}
|
|
|
|
|
|
static int LZ4_compress_destSize_extState (LZ4_stream_t* state, const char* src, char* dst, int* srcSizePtr, int targetDstSize)
|
|
{
|
|
LZ4_resetStream(state);
|
|
|
|
if (targetDstSize >= LZ4_compressBound(*srcSizePtr)) { /* compression success is guaranteed */
|
|
return LZ4_compress_fast_extState(state, src, dst, *srcSizePtr, targetDstSize, 1);
|
|
} else {
|
|
if (*srcSizePtr < LZ4_64Klimit)
|
|
return LZ4_compress_destSize_generic(&state->internal_donotuse, src, dst, srcSizePtr, targetDstSize, byU16);
|
|
else
|
|
return LZ4_compress_destSize_generic(&state->internal_donotuse, src, dst, srcSizePtr, targetDstSize, sizeof(void*)==8 ? byU32 : byPtr);
|
|
}
|
|
}
|
|
|
|
|
|
int LZ4_compress_destSize(const char* src, char* dst, int* srcSizePtr, int targetDstSize)
|
|
{
|
|
#if (HEAPMODE)
|
|
LZ4_stream_t* ctx = (LZ4_stream_t*)ALLOCATOR(1, sizeof(LZ4_stream_t)); /* malloc-calloc always properly aligned */
|
|
#else
|
|
LZ4_stream_t ctxBody;
|
|
LZ4_stream_t* ctx = &ctxBody;
|
|
#endif
|
|
|
|
int result = LZ4_compress_destSize_extState(ctx, src, dst, srcSizePtr, targetDstSize);
|
|
|
|
#if (HEAPMODE)
|
|
FREEMEM(ctx);
|
|
#endif
|
|
return result;
|
|
}
|
|
|
|
|
|
|
|
/*-******************************
|
|
* Streaming functions
|
|
********************************/
|
|
|
|
LZ4_stream_t* LZ4_createStream(void)
|
|
{
|
|
LZ4_stream_t* lz4s = (LZ4_stream_t*)ALLOCATOR(8, LZ4_STREAMSIZE_U64);
|
|
LZ4_STATIC_ASSERT(LZ4_STREAMSIZE >= sizeof(LZ4_stream_t_internal)); /* A compilation error here means LZ4_STREAMSIZE is not large enough */
|
|
LZ4_resetStream(lz4s);
|
|
return lz4s;
|
|
}
|
|
|
|
void LZ4_resetStream (LZ4_stream_t* LZ4_stream)
|
|
{
|
|
MEM_INIT(LZ4_stream, 0, sizeof(LZ4_stream_t));
|
|
}
|
|
|
|
int LZ4_freeStream (LZ4_stream_t* LZ4_stream)
|
|
{
|
|
FREEMEM(LZ4_stream);
|
|
return (0);
|
|
}
|
|
|
|
|
|
#define HASH_UNIT sizeof(reg_t)
|
|
int LZ4_loadDict (LZ4_stream_t* LZ4_dict, const char* dictionary, int dictSize)
|
|
{
|
|
LZ4_stream_t_internal* dict = &LZ4_dict->internal_donotuse;
|
|
const BYTE* p = (const BYTE*)dictionary;
|
|
const BYTE* const dictEnd = p + dictSize;
|
|
const BYTE* base;
|
|
|
|
if ((dict->initCheck) || (dict->currentOffset > 1 GB)) /* Uninitialized structure, or reuse overflow */
|
|
LZ4_resetStream(LZ4_dict);
|
|
|
|
if (dictSize < (int)HASH_UNIT) {
|
|
dict->dictionary = NULL;
|
|
dict->dictSize = 0;
|
|
return 0;
|
|
}
|
|
|
|
if ((dictEnd - p) > 64 KB) p = dictEnd - 64 KB;
|
|
dict->currentOffset += 64 KB;
|
|
base = p - dict->currentOffset;
|
|
dict->dictionary = p;
|
|
dict->dictSize = (U32)(dictEnd - p);
|
|
dict->currentOffset += dict->dictSize;
|
|
|
|
while (p <= dictEnd-HASH_UNIT) {
|
|
LZ4_putPosition(p, dict->hashTable, byU32, base);
|
|
p+=3;
|
|
}
|
|
|
|
return dict->dictSize;
|
|
}
|
|
|
|
|
|
static void LZ4_renormDictT(LZ4_stream_t_internal* LZ4_dict, const BYTE* src)
|
|
{
|
|
if ((LZ4_dict->currentOffset > 0x80000000) ||
|
|
((uptrval)LZ4_dict->currentOffset > (uptrval)src)) { /* address space overflow */
|
|
/* rescale hash table */
|
|
U32 const delta = LZ4_dict->currentOffset - 64 KB;
|
|
const BYTE* dictEnd = LZ4_dict->dictionary + LZ4_dict->dictSize;
|
|
int i;
|
|
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;
|
|
}
|
|
}
|
|
|
|
|
|
int LZ4_compress_fast_continue (LZ4_stream_t* LZ4_stream, const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration)
|
|
{
|
|
LZ4_stream_t_internal* streamPtr = &LZ4_stream->internal_donotuse;
|
|
const BYTE* const dictEnd = streamPtr->dictionary + streamPtr->dictSize;
|
|
|
|
const BYTE* smallest = (const BYTE*) source;
|
|
if (streamPtr->initCheck) return 0; /* Uninitialized structure detected */
|
|
if ((streamPtr->dictSize>0) && (smallest>dictEnd)) smallest = dictEnd;
|
|
LZ4_renormDictT(streamPtr, smallest);
|
|
if (acceleration < 1) acceleration = ACCELERATION_DEFAULT;
|
|
|
|
/* 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) {
|
|
int result;
|
|
if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset))
|
|
result = LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, byU32, withPrefix64k, dictSmall, acceleration);
|
|
else
|
|
result = LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, byU32, withPrefix64k, noDictIssue, acceleration);
|
|
streamPtr->dictSize += (U32)inputSize;
|
|
streamPtr->currentOffset += (U32)inputSize;
|
|
return result;
|
|
}
|
|
|
|
/* external dictionary mode */
|
|
{ int result;
|
|
if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset))
|
|
result = LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, byU32, usingExtDict, dictSmall, acceleration);
|
|
else
|
|
result = LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, byU32, usingExtDict, noDictIssue, acceleration);
|
|
streamPtr->dictionary = (const BYTE*)source;
|
|
streamPtr->dictSize = (U32)inputSize;
|
|
streamPtr->currentOffset += (U32)inputSize;
|
|
return result;
|
|
}
|
|
}
|
|
|
|
|
|
/* Hidden debug function, to force external dictionary mode */
|
|
int LZ4_compress_forceExtDict (LZ4_stream_t* LZ4_dict, const char* source, char* dest, int inputSize)
|
|
{
|
|
LZ4_stream_t_internal* streamPtr = &LZ4_dict->internal_donotuse;
|
|
int result;
|
|
const BYTE* const dictEnd = streamPtr->dictionary + streamPtr->dictSize;
|
|
|
|
const BYTE* smallest = dictEnd;
|
|
if (smallest > (const BYTE*) source) smallest = (const BYTE*) source;
|
|
LZ4_renormDictT(streamPtr, smallest);
|
|
|
|
result = LZ4_compress_generic(streamPtr, source, dest, inputSize, 0, notLimited, byU32, usingExtDict, noDictIssue, 1);
|
|
|
|
streamPtr->dictionary = (const BYTE*)source;
|
|
streamPtr->dictSize = (U32)inputSize;
|
|
streamPtr->currentOffset += (U32)inputSize;
|
|
|
|
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 */
|
|
if ((U32)dictSize > dict->dictSize) dictSize = dict->dictSize;
|
|
|
|
memmove(safeBuffer, previousDictEnd - dictSize, dictSize);
|
|
|
|
dict->dictionary = (const BYTE*)safeBuffer;
|
|
dict->dictSize = (U32)dictSize;
|
|
|
|
return dictSize;
|
|
}
|
|
|
|
|
|
|
|
/*-*****************************
|
|
* Decompression functions
|
|
*******************************/
|
|
/*! LZ4_decompress_generic() :
|
|
* This generic decompression function cover all use cases.
|
|
* It shall be instantiated several times, using different sets of directives
|
|
* Note that it is important this generic function is really inlined,
|
|
* in order to remove useless branches during compilation optimization.
|
|
*/
|
|
FORCE_INLINE int LZ4_decompress_generic(
|
|
const char* const source,
|
|
char* const dest,
|
|
int inputSize,
|
|
int outputSize, /* If endOnInput==endOnInputSize, this value is the max size of Output Buffer. */
|
|
|
|
int endOnInput, /* endOnOutputSize, endOnInputSize */
|
|
int partialDecoding, /* full, partial */
|
|
int targetOutputSize, /* only used if partialDecoding==partial */
|
|
int dict, /* noDict, withPrefix64k, usingExtDict */
|
|
const BYTE* const lowPrefix, /* == dest when no prefix */
|
|
const BYTE* const dictStart, /* only if dict==usingExtDict */
|
|
const size_t dictSize /* note : = 0 if noDict */
|
|
)
|
|
{
|
|
/* Local Variables */
|
|
const BYTE* ip = (const BYTE*) source;
|
|
const BYTE* const iend = ip + inputSize;
|
|
|
|
BYTE* op = (BYTE*) dest;
|
|
BYTE* const oend = op + outputSize;
|
|
BYTE* cpy;
|
|
BYTE* oexit = op + targetOutputSize;
|
|
const BYTE* const lowLimit = lowPrefix - dictSize;
|
|
|
|
const BYTE* const dictEnd = (const BYTE*)dictStart + dictSize;
|
|
const unsigned dec32table[] = {0, 1, 2, 1, 4, 4, 4, 4};
|
|
const int dec64table[] = {0, 0, 0, -1, 0, 1, 2, 3};
|
|
|
|
const int safeDecode = (endOnInput==endOnInputSize);
|
|
const int checkOffset = ((safeDecode) && (dictSize < (int)(64 KB)));
|
|
|
|
|
|
/* Special cases */
|
|
if ((partialDecoding) && (oexit > oend-MFLIMIT)) oexit = oend-MFLIMIT; /* targetOutputSize too high => decode everything */
|
|
if ((endOnInput) && (unlikely(outputSize==0))) return ((inputSize==1) && (*ip==0)) ? 0 : -1; /* Empty output buffer */
|
|
if ((!endOnInput) && (unlikely(outputSize==0))) return (*ip==0?1:-1);
|
|
|
|
/* Main Loop : decode sequences */
|
|
while (1) {
|
|
size_t length;
|
|
const BYTE* match;
|
|
size_t offset;
|
|
|
|
/* get literal length */
|
|
unsigned const token = *ip++;
|
|
if ((length=(token>>ML_BITS)) == RUN_MASK) {
|
|
unsigned s;
|
|
do {
|
|
s = *ip++;
|
|
length += s;
|
|
} while ( likely(endOnInput ? ip<iend-RUN_MASK : 1) & (s==255) );
|
|
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;
|
|
if ( ((endOnInput) && ((cpy>(partialDecoding?oexit:oend-MFLIMIT)) || (ip+length>iend-(2+1+LASTLITERALS))) )
|
|
|| ((!endOnInput) && (cpy>oend-WILDCOPYLENGTH)) )
|
|
{
|
|
if (partialDecoding) {
|
|
if (cpy > oend) goto _output_error; /* Error : write attempt beyond end of output buffer */
|
|
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;
|
|
break; /* Necessarily EOF, due to parsing restrictions */
|
|
}
|
|
LZ4_wildCopy(op, ip, cpy);
|
|
ip += length; op = cpy;
|
|
|
|
/* get offset */
|
|
offset = LZ4_readLE16(ip); ip+=2;
|
|
match = op - offset;
|
|
if ((checkOffset) && (unlikely(match < lowLimit))) goto _output_error; /* Error : offset outside buffers */
|
|
LZ4_write32(op, (U32)offset); /* costs ~1%; silence an msan warning when offset==0 */
|
|
|
|
/* get matchlength */
|
|
length = token & ML_MASK;
|
|
if (length == ML_MASK) {
|
|
unsigned s;
|
|
do {
|
|
s = *ip++;
|
|
if ((endOnInput) && (ip > iend-LASTLITERALS)) goto _output_error;
|
|
length += s;
|
|
} while (s==255);
|
|
if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)op)) goto _output_error; /* overflow detection */
|
|
}
|
|
length += MINMATCH;
|
|
|
|
/* check external dictionary */
|
|
if ((dict==usingExtDict) && (match < lowPrefix)) {
|
|
if (unlikely(op+length > oend-LASTLITERALS)) goto _output_error; /* doesn't respect parsing restriction */
|
|
|
|
if (length <= (size_t)(lowPrefix-match)) {
|
|
/* match can be copied as a single segment from external dictionary */
|
|
memmove(op, dictEnd - (lowPrefix-match), length);
|
|
op += length;
|
|
} else {
|
|
/* match encompass 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;
|
|
}
|
|
|
|
/* copy match within block */
|
|
cpy = op + length;
|
|
if (unlikely(offset<8)) {
|
|
const int dec64 = dec64table[offset];
|
|
op[0] = match[0];
|
|
op[1] = match[1];
|
|
op[2] = match[2];
|
|
op[3] = match[3];
|
|
match += dec32table[offset];
|
|
memcpy(op+4, match, 4);
|
|
match -= dec64;
|
|
} else { LZ4_copy8(op, match); match+=8; }
|
|
op += 8;
|
|
|
|
if (unlikely(cpy>oend-12)) {
|
|
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_wildCopy(op, match, oCopyLimit);
|
|
match += oCopyLimit - op;
|
|
op = oCopyLimit;
|
|
}
|
|
while (op<cpy) *op++ = *match++;
|
|
} else {
|
|
LZ4_copy8(op, match);
|
|
if (length>16) LZ4_wildCopy(op+8, match+8, cpy);
|
|
}
|
|
op=cpy; /* correction */
|
|
}
|
|
|
|
/* end of decoding */
|
|
if (endOnInput)
|
|
return (int) (((char*)op)-dest); /* Nb of output bytes decoded */
|
|
else
|
|
return (int) (((const char*)ip)-source); /* Nb of input bytes read */
|
|
|
|
/* Overflow error detected */
|
|
_output_error:
|
|
return (int) (-(((const char*)ip)-source))-1;
|
|
}
|
|
|
|
|
|
int LZ4_decompress_safe(const char* source, char* dest, int compressedSize, int maxDecompressedSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxDecompressedSize, endOnInputSize, full, 0, noDict, (BYTE*)dest, NULL, 0);
|
|
}
|
|
|
|
int LZ4_decompress_safe_partial(const char* source, char* dest, int compressedSize, int targetOutputSize, int maxDecompressedSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxDecompressedSize, endOnInputSize, partial, targetOutputSize, noDict, (BYTE*)dest, NULL, 0);
|
|
}
|
|
|
|
int LZ4_decompress_fast(const char* source, char* dest, int originalSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, 0, originalSize, endOnOutputSize, full, 0, withPrefix64k, (BYTE*)(dest - 64 KB), NULL, 64 KB);
|
|
}
|
|
|
|
|
|
/*===== streaming decompression functions =====*/
|
|
|
|
/*
|
|
* If you prefer dynamic allocation methods,
|
|
* LZ4_createStreamDecode()
|
|
* provides a pointer (void*) towards an initialized LZ4_streamDecode_t structure.
|
|
*/
|
|
LZ4_streamDecode_t* LZ4_createStreamDecode(void)
|
|
{
|
|
LZ4_streamDecode_t* lz4s = (LZ4_streamDecode_t*) ALLOCATOR(1, sizeof(LZ4_streamDecode_t));
|
|
return lz4s;
|
|
}
|
|
|
|
int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream)
|
|
{
|
|
FREEMEM(LZ4_stream);
|
|
return 0;
|
|
}
|
|
|
|
/*!
|
|
* 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
|
|
*/
|
|
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;
|
|
}
|
|
|
|
/*
|
|
*_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()
|
|
*/
|
|
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;
|
|
|
|
if (lz4sd->prefixEnd == (BYTE*)dest) {
|
|
result = LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
|
|
endOnInputSize, full, 0,
|
|
usingExtDict, lz4sd->prefixEnd - lz4sd->prefixSize, lz4sd->externalDict, lz4sd->extDictSize);
|
|
if (result <= 0) return result;
|
|
lz4sd->prefixSize += result;
|
|
lz4sd->prefixEnd += result;
|
|
} else {
|
|
lz4sd->extDictSize = lz4sd->prefixSize;
|
|
lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize;
|
|
result = LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
|
|
endOnInputSize, full, 0,
|
|
usingExtDict, (BYTE*)dest, lz4sd->externalDict, lz4sd->extDictSize);
|
|
if (result <= 0) return result;
|
|
lz4sd->prefixSize = result;
|
|
lz4sd->prefixEnd = (BYTE*)dest + result;
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
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;
|
|
|
|
if (lz4sd->prefixEnd == (BYTE*)dest) {
|
|
result = LZ4_decompress_generic(source, dest, 0, originalSize,
|
|
endOnOutputSize, full, 0,
|
|
usingExtDict, lz4sd->prefixEnd - lz4sd->prefixSize, lz4sd->externalDict, lz4sd->extDictSize);
|
|
if (result <= 0) return result;
|
|
lz4sd->prefixSize += originalSize;
|
|
lz4sd->prefixEnd += originalSize;
|
|
} else {
|
|
lz4sd->extDictSize = lz4sd->prefixSize;
|
|
lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize;
|
|
result = LZ4_decompress_generic(source, dest, 0, originalSize,
|
|
endOnOutputSize, full, 0,
|
|
usingExtDict, (BYTE*)dest, lz4sd->externalDict, lz4sd->extDictSize);
|
|
if (result <= 0) return result;
|
|
lz4sd->prefixSize = originalSize;
|
|
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
|
|
*/
|
|
|
|
FORCE_INLINE int LZ4_decompress_usingDict_generic(const char* source, char* dest, int compressedSize, int maxOutputSize, int safe, const char* dictStart, int dictSize)
|
|
{
|
|
if (dictSize==0)
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, safe, full, 0, noDict, (BYTE*)dest, NULL, 0);
|
|
if (dictStart+dictSize == dest) {
|
|
if (dictSize >= (int)(64 KB - 1))
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, safe, full, 0, withPrefix64k, (BYTE*)dest-64 KB, NULL, 0);
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, safe, full, 0, noDict, (BYTE*)dest-dictSize, NULL, 0);
|
|
}
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, safe, full, 0, usingExtDict, (BYTE*)dest, (const BYTE*)dictStart, dictSize);
|
|
}
|
|
|
|
int LZ4_decompress_safe_usingDict(const char* source, char* dest, int compressedSize, int maxOutputSize, const char* dictStart, int dictSize)
|
|
{
|
|
return LZ4_decompress_usingDict_generic(source, dest, compressedSize, maxOutputSize, 1, dictStart, dictSize);
|
|
}
|
|
|
|
int LZ4_decompress_fast_usingDict(const char* source, char* dest, int originalSize, const char* dictStart, int dictSize)
|
|
{
|
|
return LZ4_decompress_usingDict_generic(source, dest, 0, originalSize, 0, dictStart, dictSize);
|
|
}
|
|
|
|
/* debug function */
|
|
int LZ4_decompress_safe_forceExtDict(const char* source, char* dest, int compressedSize, int maxOutputSize, const char* dictStart, int dictSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, usingExtDict, (BYTE*)dest, (const BYTE*)dictStart, dictSize);
|
|
}
|
|
|
|
|
|
/*=*************************************************
|
|
* Obsolete Functions
|
|
***************************************************/
|
|
/* obsolete compression functions */
|
|
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 maxDstSize) { return LZ4_compress_fast_continue(LZ4_stream, src, dst, srcSize, maxDstSize, 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); }
|
|
|
|
/*
|
|
These function names are deprecated and should no longer be used.
|
|
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
|
|
*/
|
|
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); }
|
|
|
|
|
|
/* Obsolete Streaming functions */
|
|
|
|
int LZ4_sizeofStreamState() { return LZ4_STREAMSIZE; }
|
|
|
|
static void LZ4_init(LZ4_stream_t* lz4ds, BYTE* base)
|
|
{
|
|
MEM_INIT(lz4ds, 0, sizeof(LZ4_stream_t));
|
|
lz4ds->internal_donotuse.bufferStart = base;
|
|
}
|
|
|
|
int LZ4_resetStreamState(void* state, char* inputBuffer)
|
|
{
|
|
if ((((uptrval)state) & 3) != 0) return 1; /* Error : pointer is not aligned on 4-bytes boundary */
|
|
LZ4_init((LZ4_stream_t*)state, (BYTE*)inputBuffer);
|
|
return 0;
|
|
}
|
|
|
|
void* LZ4_create (char* inputBuffer)
|
|
{
|
|
LZ4_stream_t* lz4ds = (LZ4_stream_t*)ALLOCATOR(8, sizeof(LZ4_stream_t));
|
|
LZ4_init (lz4ds, (BYTE*)inputBuffer);
|
|
return lz4ds;
|
|
}
|
|
|
|
char* LZ4_slideInputBuffer (void* LZ4_Data)
|
|
{
|
|
LZ4_stream_t_internal* ctx = &((LZ4_stream_t*)LZ4_Data)->internal_donotuse;
|
|
int dictSize = LZ4_saveDict((LZ4_stream_t*)LZ4_Data, (char*)ctx->bufferStart, 64 KB);
|
|
return (char*)(ctx->bufferStart + dictSize);
|
|
}
|
|
|
|
/* Obsolete streaming decompression functions */
|
|
|
|
int LZ4_decompress_safe_withPrefix64k(const char* source, char* dest, int compressedSize, int maxOutputSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, withPrefix64k, (BYTE*)dest - 64 KB, NULL, 64 KB);
|
|
}
|
|
|
|
int LZ4_decompress_fast_withPrefix64k(const char* source, char* dest, int originalSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, 0, originalSize, endOnOutputSize, full, 0, withPrefix64k, (BYTE*)dest - 64 KB, NULL, 64 KB);
|
|
}
|
|
|
|
#endif /* LZ4_COMMONDEFS_ONLY */
|