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https://github.com/Atmosphere-NX/Atmosphere
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subrepo: subdir: "stratosphere/libstratosphere" merged: "0c5dab80" upstream: origin: "https://github.com/Atmosphere-NX/libstratosphere" branch: "master" commit: "0c5dab80" git-subrepo: version: "0.4.0" origin: "https://github.com/ingydotnet/git-subrepo" commit: "5d6aba9"
1857 lines
76 KiB
C
1857 lines
76 KiB
C
/*
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LZ4 - Fast LZ compression algorithm
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Copyright (C) 2011-2017, 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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* LZ4_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 LZ4_HEAPMODE
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# define LZ4_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 assembly generation depends 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 */
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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
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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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#define LZ4_STATIC_LINKING_ONLY
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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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# 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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#endif /* _MSC_VER */
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#ifndef LZ4_FORCE_INLINE
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# ifdef _MSC_VER /* Visual Studio */
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# define LZ4_FORCE_INLINE static __forceinline
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# else
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# if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */
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# ifdef __GNUC__
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# define LZ4_FORCE_INLINE static inline __attribute__((always_inline))
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# else
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# define LZ4_FORCE_INLINE static inline
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# endif
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# else
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# define LZ4_FORCE_INLINE static
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# endif /* __STDC_VERSION__ */
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# endif /* _MSC_VER */
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#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_wildCopy,
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* together with a simple 8-byte copy loop as a fall-back path.
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* However, this optimization hurts the decompression speed by >30%,
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* because the execution does not go to the optimized loop
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* for typical compressible data, and all of the preamble checks
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* before going to the fall-back path become useless overhead.
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* This optimization happens only with the -O3 flag, and -O2 generates
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* a simple 8-byte copy loop.
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* With gcc on ppc64le, all of the LZ4_decompress_* and LZ4_wildCopy
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* functions are annotated with __attribute__((optimize("O2"))),
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* and also LZ4_wildCopy is forcibly inlined, so that the O2 attribute
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* of LZ4_wildCopy does not affect the compression speed.
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*/
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#if defined(__PPC64__) && defined(__LITTLE_ENDIAN__) && defined(__GNUC__)
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# define LZ4_FORCE_O2_GCC_PPC64LE __attribute__((optimize("O2")))
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# define LZ4_FORCE_O2_INLINE_GCC_PPC64LE __attribute__((optimize("O2"))) LZ4_FORCE_INLINE
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#else
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# define LZ4_FORCE_O2_GCC_PPC64LE
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# define LZ4_FORCE_O2_INLINE_GCC_PPC64LE static
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#endif
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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 ALLOC(s) malloc(s)
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#define ALLOC_AND_ZERO(s) calloc(1,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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/* 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_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 { memcpy(d,s,8); 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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* Error detection
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**************************************/
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#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=1)
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# include <assert.h>
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#else
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# ifndef assert
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# define assert(condition) ((void)0)
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# endif
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#endif
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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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#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=2)
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# include <stdio.h>
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static int g_debuglog_enable = 1;
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# define DEBUGLOG(l, ...) { \
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if ((g_debuglog_enable) && (l<=LZ4_DEBUG)) { \
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fprintf(stderr, __FILE__ ": "); \
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fprintf(stderr, __VA_ARGS__); \
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fprintf(stderr, " \n"); \
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} }
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#else
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# define DEBUGLOG(l, ...) {} /* disabled */
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#endif
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/*-************************************
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* Common functions
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**************************************/
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static unsigned LZ4_NbCommonBytes (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,
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0, 3, 1, 3, 1, 4, 2, 7,
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0, 2, 3, 6, 1, 5, 3, 5,
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1, 3, 4, 4, 2, 5, 6, 7,
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7, 0, 1, 2, 3, 3, 4, 6,
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2, 6, 5, 5, 3, 4, 5, 6,
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7, 1, 2, 4, 6, 4, 4, 5,
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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,
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3, 2, 2, 1, 3, 2, 0, 1,
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3, 3, 1, 2, 2, 2, 2, 0,
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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) { /* 64-bits */
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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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static const U32 by32 = sizeof(val)*4; /* 32 on 64 bits (goal), 16 on 32 bits.
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Just to avoid some static analyzer complaining about shift by 32 on 32-bits target.
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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; }
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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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LZ4_FORCE_INLINE
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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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if (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) {
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pIn+=STEPSIZE; pMatch+=STEPSIZE;
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} else {
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return LZ4_NbCommonBytes(diff);
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} }
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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; }
|
|
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
|
|
**************************************/
|
|
typedef enum { notLimited = 0, limitedOutput = 1 } limitedOutput_directive;
|
|
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;
|
|
typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive;
|
|
|
|
typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
|
|
typedef enum { full = 0, partial = 1 } earlyEnd_directive;
|
|
|
|
|
|
/*-************************************
|
|
* Local Utils
|
|
**************************************/
|
|
int LZ4_versionNumber (void) { return LZ4_VERSION_NUMBER; }
|
|
const char* LZ4_versionString(void) { return LZ4_VERSION_STRING; }
|
|
int LZ4_compressBound(int isize) { return LZ4_COMPRESSBOUND(isize); }
|
|
int LZ4_sizeofState() { return LZ4_STREAMSIZE; }
|
|
|
|
|
|
/*-******************************
|
|
* Compression functions
|
|
********************************/
|
|
static U32 LZ4_hash4(U32 sequence, tableType_t const tableType)
|
|
{
|
|
if (tableType == byU16)
|
|
return ((sequence * 2654435761U) >> ((MINMATCH*8)-(LZ4_HASHLOG+1)));
|
|
else
|
|
return ((sequence * 2654435761U) >> ((MINMATCH*8)-LZ4_HASHLOG));
|
|
}
|
|
|
|
static U32 LZ4_hash5(U64 sequence, tableType_t const tableType)
|
|
{
|
|
static const U64 prime5bytes = 889523592379ULL;
|
|
static const U64 prime8bytes = 11400714785074694791ULL;
|
|
const U32 hashLog = (tableType == byU16) ? LZ4_HASHLOG+1 : LZ4_HASHLOG;
|
|
if (LZ4_isLittleEndian())
|
|
return (U32)(((sequence << 24) * prime5bytes) >> (64 - hashLog));
|
|
else
|
|
return (U32)(((sequence >> 24) * prime8bytes) >> (64 - hashLog));
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
static void LZ4_putIndexOnHash(U32 idx, U32 h, void* tableBase, tableType_t const tableType)
|
|
{
|
|
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; }
|
|
}
|
|
}
|
|
|
|
static void LZ4_putPositionOnHash(const BYTE* p, U32 h, void* tableBase, tableType_t const tableType, const BYTE* srcBase)
|
|
{
|
|
switch (tableType)
|
|
{
|
|
case clearedTable: { /* illegal! */ assert(0); return; }
|
|
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);
|
|
}
|
|
|
|
/* 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)
|
|
*/
|
|
static U32 LZ4_getIndexOnHash(U32 h, const void* tableBase, tableType_t tableType)
|
|
{
|
|
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 */
|
|
}
|
|
|
|
static const BYTE* LZ4_getPositionOnHash(U32 h, const void* tableBase, tableType_t tableType, const BYTE* srcBase)
|
|
{
|
|
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 */
|
|
}
|
|
|
|
LZ4_FORCE_INLINE const BYTE* LZ4_getPosition(const BYTE* p, const void* tableBase, tableType_t tableType, const BYTE* srcBase)
|
|
{
|
|
U32 const h = LZ4_hashPosition(p, tableType);
|
|
return LZ4_getPositionOnHash(h, tableBase, tableType, srcBase);
|
|
}
|
|
|
|
LZ4_FORCE_INLINE void LZ4_prepareTable(
|
|
LZ4_stream_t_internal* const cctx,
|
|
const int inputSize,
|
|
const tableType_t tableType) {
|
|
/* 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)");
|
|
}
|
|
}
|
|
|
|
/* Adding a gap, so all previous entries are > MAX_DISTANCE back, is faster
|
|
* 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;
|
|
}
|
|
|
|
/** 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,
|
|
const int maxOutputSize,
|
|
const limitedOutput_directive outputLimited,
|
|
const tableType_t tableType,
|
|
const dict_directive dictDirective,
|
|
const dictIssue_directive dictIssue,
|
|
const U32 acceleration)
|
|
{
|
|
const BYTE* ip = (const BYTE*) source;
|
|
|
|
U32 const startIndex = cctx->currentOffset;
|
|
const BYTE* base = (const BYTE*) source - startIndex;
|
|
const BYTE* lowLimit;
|
|
|
|
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;
|
|
const BYTE* anchor = (const BYTE*) source;
|
|
const BYTE* const iend = ip + inputSize;
|
|
const BYTE* const mflimitPlusOne = iend - MFLIMIT + 1;
|
|
const BYTE* const matchlimit = iend - LASTLITERALS;
|
|
|
|
/* the dictCtx currentOffset is indexed on the start of the dictionary,
|
|
* while a dictionary in the current context precedes the currentOffset */
|
|
const BYTE* dictBase = dictDirective == usingDictCtx ?
|
|
dictionary + dictSize - dictCtx->currentOffset : /* is it possible that dictCtx->currentOffset != dictCtx->dictSize ? Yes if the dictionary context is not reset */
|
|
dictionary + dictSize - startIndex;
|
|
|
|
BYTE* op = (BYTE*) dest;
|
|
BYTE* const olimit = op + maxOutputSize;
|
|
|
|
U32 offset = 0;
|
|
U32 forwardH;
|
|
|
|
DEBUGLOG(5, "LZ4_compress_generic: srcSize=%i, tableType=%u", inputSize, tableType);
|
|
/* Init conditions */
|
|
if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported inputSize, too large (or negative) */
|
|
if (tableType==byPtr) assert(dictDirective==noDict); /* only supported use case with byPtr */
|
|
assert(acceleration >= 1);
|
|
|
|
lowLimit = (const BYTE*)source - (dictDirective == withPrefix64k ? dictSize : 0);
|
|
|
|
if ((tableType == byU16) && (inputSize>=LZ4_64Klimit)) return 0; /* Size too large (not within 64K limit) */
|
|
|
|
/* 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;
|
|
}
|
|
cctx->currentOffset += (U32)inputSize;
|
|
cctx->tableType = tableType;
|
|
|
|
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 ( ; ; ) {
|
|
const BYTE* match;
|
|
BYTE* token;
|
|
|
|
/* Find a match */
|
|
if (tableType == byPtr) {
|
|
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 > mflimitPlusOne)) goto _last_literals;
|
|
assert(ip < mflimitPlusOne);
|
|
|
|
match = LZ4_getPositionOnHash(h, cctx->hashTable, tableType, base);
|
|
forwardH = LZ4_hashPosition(forwardIp, tableType);
|
|
LZ4_putPositionOnHash(ip, h, cctx->hashTable, tableType, base);
|
|
|
|
} while ( (match+MAX_DISTANCE < ip)
|
|
|| (LZ4_read32(match) != LZ4_read32(ip)) );
|
|
|
|
} else { /* byU32, byU16 */
|
|
|
|
const BYTE* forwardIp = ip;
|
|
unsigned step = 1;
|
|
unsigned searchMatchNb = acceleration << LZ4_skipTrigger;
|
|
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);
|
|
match = dictBase + matchIndex;
|
|
lowLimit = dictionary;
|
|
} else {
|
|
match = base + matchIndex;
|
|
lowLimit = (const BYTE*)source;
|
|
}
|
|
} else { /* single continuous memory segment */
|
|
match = base + matchIndex;
|
|
}
|
|
forwardH = LZ4_hashPosition(forwardIp, tableType);
|
|
LZ4_putIndexOnHash(current, h, cctx->hashTable, tableType);
|
|
|
|
if ((dictIssue == dictSmall) && (matchIndex < prefixIdxLimit)) continue; /* match outside of valid area */
|
|
if ((tableType != byU16) && (current - matchIndex > MAX_DISTANCE)) continue; /* too far - note: works even if matchIndex overflows */
|
|
if (tableType == byU16) assert((current - matchIndex) <= MAX_DISTANCE); /* too_far presumed impossible with byU16 */
|
|
|
|
if (LZ4_read32(match) == LZ4_read32(ip)) {
|
|
if (maybe_extMem) offset = current - matchIndex;
|
|
break; /* match found */
|
|
}
|
|
|
|
} while(1);
|
|
}
|
|
|
|
/* Catch up */
|
|
while (((ip>anchor) & (match > lowLimit)) && (unlikely(ip[-1]==match[-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;
|
|
DEBUGLOG(6, "seq.start:%i, literals=%u, match.start:%i", (int)(anchor-(const BYTE*)source), litLength, (int)(ip-(const BYTE*)source));
|
|
}
|
|
|
|
_next_match:
|
|
/* 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
|
|
*/
|
|
|
|
/* Encode Offset */
|
|
if (maybe_extMem) { /* static test */
|
|
DEBUGLOG(6, " with offset=%u (ext if > %i)", offset, (int)(ip - (const BYTE*)source));
|
|
assert(offset <= MAX_DISTANCE && offset > 0);
|
|
LZ4_writeLE16(op, (U16)offset); op+=2;
|
|
} else {
|
|
DEBUGLOG(6, " with offset=%u (same segment)", (U32)(ip - match));
|
|
assert(ip-match <= MAX_DISTANCE);
|
|
LZ4_writeLE16(op, (U16)(ip - match)); op+=2;
|
|
}
|
|
|
|
/* Encode MatchLength */
|
|
{ unsigned matchCode;
|
|
|
|
if ( (dictDirective==usingExtDict || dictDirective==usingDictCtx)
|
|
&& (lowLimit==dictionary) /* match within extDict */ ) {
|
|
const BYTE* limit = ip + (dictEnd-match);
|
|
assert(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(limit, (const BYTE*)source, matchlimit);
|
|
matchCode += more;
|
|
ip += more;
|
|
}
|
|
DEBUGLOG(6, " with matchLength=%u starting in extDict", matchCode+MINMATCH);
|
|
} else {
|
|
matchCode = LZ4_count(ip+MINMATCH, match+MINMATCH, matchlimit);
|
|
ip += MINMATCH + matchCode;
|
|
DEBUGLOG(6, " with matchLength=%u", matchCode+MINMATCH);
|
|
}
|
|
|
|
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 >= mflimitPlusOne) break;
|
|
|
|
/* Fill table */
|
|
LZ4_putPosition(ip-2, cctx->hashTable, tableType, base);
|
|
|
|
/* Test next position */
|
|
if (tableType == byPtr) {
|
|
|
|
match = LZ4_getPosition(ip, cctx->hashTable, tableType, base);
|
|
LZ4_putPosition(ip, cctx->hashTable, tableType, base);
|
|
if ( (match+MAX_DISTANCE >= ip)
|
|
&& (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);
|
|
if ( ((dictIssue==dictSmall) ? (matchIndex >= prefixIdxLimit) : 1)
|
|
&& ((tableType==byU16) ? 1 : (current - matchIndex <= MAX_DISTANCE))
|
|
&& (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;
|
|
}
|
|
}
|
|
|
|
/* 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;
|
|
}
|
|
|
|
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;
|
|
if (acceleration < 1) acceleration = ACCELERATION_DEFAULT;
|
|
LZ4_resetStream((LZ4_stream_t*)state);
|
|
if (maxOutputSize >= LZ4_compressBound(inputSize)) {
|
|
if (inputSize < LZ4_64Klimit) {
|
|
return LZ4_compress_generic(ctx, source, dest, inputSize, 0, notLimited, byU16, noDict, noDictIssue, acceleration);
|
|
} else {
|
|
const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)source > MAX_DISTANCE)) ? byPtr : byU32;
|
|
return LZ4_compress_generic(ctx, source, dest, inputSize, 0, notLimited, tableType, noDict, noDictIssue, acceleration);
|
|
}
|
|
} else {
|
|
if (inputSize < LZ4_64Klimit) {;
|
|
return LZ4_compress_generic(ctx, source, dest, inputSize, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue, acceleration);
|
|
} else {
|
|
const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)source > MAX_DISTANCE)) ? byPtr : byU32;
|
|
return LZ4_compress_generic(ctx, source, dest, inputSize, 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, 0, notLimited, tableType, noDict, dictSmall, acceleration);
|
|
} else {
|
|
return LZ4_compress_generic(ctx, src, dst, srcSize, 0, notLimited, tableType, noDict, noDictIssue, acceleration);
|
|
}
|
|
} else {
|
|
const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)src > MAX_DISTANCE)) ? byPtr : byU32;
|
|
LZ4_prepareTable(ctx, srcSize, tableType);
|
|
return LZ4_compress_generic(ctx, src, dst, srcSize, 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, dstCapacity, limitedOutput, tableType, noDict, dictSmall, acceleration);
|
|
} else {
|
|
return LZ4_compress_generic(ctx, src, dst, srcSize, dstCapacity, limitedOutput, tableType, noDict, noDictIssue, acceleration);
|
|
}
|
|
} else {
|
|
const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)src > MAX_DISTANCE)) ? byPtr : byU32;
|
|
LZ4_prepareTable(ctx, srcSize, tableType);
|
|
return LZ4_compress_generic(ctx, src, dst, srcSize, dstCapacity, limitedOutput, tableType, noDict, noDictIssue, acceleration);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
int LZ4_compress_fast(const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration)
|
|
{
|
|
int result;
|
|
#if (LZ4_HEAPMODE)
|
|
LZ4_stream_t* ctxPtr = ALLOC(sizeof(LZ4_stream_t)); /* malloc-calloc always properly aligned */
|
|
if (ctxPtr == NULL) return 0;
|
|
#else
|
|
LZ4_stream_t ctx;
|
|
LZ4_stream_t* const ctxPtr = &ctx;
|
|
#endif
|
|
result = LZ4_compress_fast_extState(ctxPtr, source, dest, inputSize, maxOutputSize, acceleration);
|
|
|
|
#if (LZ4_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 {
|
|
tableType_t const tableType = ((sizeof(void*)==4) && ((uptrval)src > MAX_DISTANCE)) ? byPtr : byU32;
|
|
return LZ4_compress_destSize_generic(&state->internal_donotuse, src, dst, srcSizePtr, targetDstSize, tableType);
|
|
} }
|
|
}
|
|
|
|
|
|
int LZ4_compress_destSize(const char* src, char* dst, int* srcSizePtr, int targetDstSize)
|
|
{
|
|
#if (LZ4_HEAPMODE)
|
|
LZ4_stream_t* ctx = (LZ4_stream_t*)ALLOC(sizeof(LZ4_stream_t)); /* malloc-calloc always properly aligned */
|
|
if (ctx == NULL) return 0;
|
|
#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)
|
|
{
|
|
LZ4_stream_t* lz4s = (LZ4_stream_t*)ALLOC(sizeof(LZ4_stream_t));
|
|
LZ4_STATIC_ASSERT(LZ4_STREAMSIZE >= sizeof(LZ4_stream_t_internal)); /* A compilation error here means LZ4_STREAMSIZE is not large enough */
|
|
DEBUGLOG(4, "LZ4_createStream %p", lz4s);
|
|
if (lz4s == NULL) return NULL;
|
|
LZ4_resetStream(lz4s);
|
|
return lz4s;
|
|
}
|
|
|
|
void LZ4_resetStream (LZ4_stream_t* LZ4_stream)
|
|
{
|
|
DEBUGLOG(5, "LZ4_resetStream (ctx:%p)", LZ4_stream);
|
|
MEM_INIT(LZ4_stream, 0, sizeof(LZ4_stream_t));
|
|
}
|
|
|
|
void LZ4_resetStream_fast(LZ4_stream_t* ctx) {
|
|
LZ4_prepareTable(&(ctx->internal_donotuse), 0, byU32);
|
|
}
|
|
|
|
int LZ4_freeStream (LZ4_stream_t* LZ4_stream)
|
|
{
|
|
if (!LZ4_stream) return 0; /* support free on NULL */
|
|
DEBUGLOG(5, "LZ4_freeStream %p", 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 tableType_t tableType = byU32;
|
|
const BYTE* p = (const BYTE*)dictionary;
|
|
const BYTE* const dictEnd = p + dictSize;
|
|
const BYTE* base;
|
|
|
|
DEBUGLOG(4, "LZ4_loadDict (%i bytes from %p into %p)", dictSize, dictionary, LZ4_dict);
|
|
|
|
LZ4_prepareTable(dict, 0, tableType);
|
|
|
|
/* We always increment the offset by 64 KB, since, if the dict is longer,
|
|
* we truncate it to the last 64k, 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 64k. */
|
|
|
|
if ((dictEnd - p) > 64 KB) p = dictEnd - 64 KB;
|
|
base = dictEnd - 64 KB - dict->currentOffset;
|
|
dict->dictionary = p;
|
|
dict->dictSize = (U32)(dictEnd - p);
|
|
dict->currentOffset += 64 KB;
|
|
dict->tableType = tableType;
|
|
|
|
if (dictSize < (int)HASH_UNIT) {
|
|
return 0;
|
|
}
|
|
|
|
while (p <= dictEnd-HASH_UNIT) {
|
|
LZ4_putPosition(p, dict->hashTable, tableType, base);
|
|
p+=3;
|
|
}
|
|
|
|
return dict->dictSize;
|
|
}
|
|
|
|
void LZ4_attach_dictionary(LZ4_stream_t *working_stream, const LZ4_stream_t *dictionary_stream) {
|
|
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;
|
|
}
|
|
}
|
|
|
|
|
|
static void LZ4_renormDictT(LZ4_stream_t_internal* LZ4_dict, int nextSize)
|
|
{
|
|
if (LZ4_dict->currentOffset + nextSize > 0x80000000) { /* potential ptrdiff_t overflow (32-bits mode) */
|
|
/* rescale hash table */
|
|
U32 const delta = LZ4_dict->currentOffset - 64 KB;
|
|
const BYTE* dictEnd = LZ4_dict->dictionary + LZ4_dict->dictSize;
|
|
int i;
|
|
DEBUGLOG(4, "LZ4_renormDictT");
|
|
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)
|
|
{
|
|
const tableType_t tableType = byU32;
|
|
LZ4_stream_t_internal* streamPtr = &LZ4_stream->internal_donotuse;
|
|
const BYTE* const dictEnd = streamPtr->dictionary + streamPtr->dictSize;
|
|
|
|
if (streamPtr->initCheck) return 0; /* Uninitialized structure detected */
|
|
LZ4_renormDictT(streamPtr, inputSize); /* avoid index overflow */
|
|
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) {
|
|
if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset))
|
|
return LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, tableType, withPrefix64k, dictSmall, acceleration);
|
|
else
|
|
return LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, tableType, withPrefix64k, noDictIssue, acceleration);
|
|
}
|
|
|
|
/* external dictionary mode */
|
|
{ int result;
|
|
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, maxOutputSize, limitedOutput, tableType, usingExtDict, noDictIssue, acceleration);
|
|
} else {
|
|
result = LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, tableType, usingDictCtx, noDictIssue, acceleration);
|
|
}
|
|
} else {
|
|
if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset)) {
|
|
result = LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, tableType, usingExtDict, dictSmall, acceleration);
|
|
} else {
|
|
result = LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, tableType, usingExtDict, noDictIssue, acceleration);
|
|
}
|
|
}
|
|
streamPtr->dictionary = (const BYTE*)source;
|
|
streamPtr->dictSize = (U32)inputSize;
|
|
return result;
|
|
}
|
|
}
|
|
|
|
|
|
/* 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)
|
|
{
|
|
LZ4_stream_t_internal* streamPtr = &LZ4_dict->internal_donotuse;
|
|
int result;
|
|
|
|
LZ4_renormDictT(streamPtr, srcSize);
|
|
|
|
if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset)) {
|
|
result = LZ4_compress_generic(streamPtr, source, dest, srcSize, 0, notLimited, byU32, usingExtDict, dictSmall, 1);
|
|
} else {
|
|
result = LZ4_compress_generic(streamPtr, source, dest, srcSize, 0, notLimited, byU32, usingExtDict, noDictIssue, 1);
|
|
}
|
|
|
|
streamPtr->dictionary = (const BYTE*)source;
|
|
streamPtr->dictSize = (U32)srcSize;
|
|
|
|
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 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.
|
|
*/
|
|
LZ4_FORCE_O2_GCC_PPC64LE
|
|
LZ4_FORCE_INLINE int LZ4_decompress_generic(
|
|
const char* const src,
|
|
char* const dst,
|
|
int srcSize,
|
|
int outputSize, /* If endOnInput==endOnInputSize, this value is `dstCapacity` */
|
|
|
|
int endOnInput, /* endOnOutputSize, endOnInputSize */
|
|
int partialDecoding, /* full, partial */
|
|
int targetOutputSize, /* only used if partialDecoding==partial */
|
|
int dict, /* noDict, withPrefix64k, usingExtDict */
|
|
const BYTE* const lowPrefix, /* always <= dst, == dst when no prefix */
|
|
const BYTE* const dictStart, /* only if dict==usingExtDict */
|
|
const size_t dictSize /* note : = 0 if noDict */
|
|
)
|
|
{
|
|
const BYTE* ip = (const BYTE*) src;
|
|
const BYTE* const iend = ip + srcSize;
|
|
|
|
BYTE* op = (BYTE*) dst;
|
|
BYTE* const oend = op + outputSize;
|
|
BYTE* cpy;
|
|
BYTE* oexit = op + targetOutputSize;
|
|
|
|
const BYTE* const dictEnd = (const BYTE*)dictStart + dictSize;
|
|
const unsigned inc32table[8] = {0, 1, 2, 1, 0, 4, 4, 4};
|
|
const int dec64table[8] = {0, 0, 0, -1, -4, 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 => just decode everything */
|
|
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);
|
|
|
|
/* Main Loop : decode sequences */
|
|
while (1) {
|
|
size_t length;
|
|
const BYTE* match;
|
|
size_t offset;
|
|
|
|
unsigned const token = *ip++;
|
|
|
|
/* shortcut for common case :
|
|
* in most circumstances, we expect to decode small matches (<= 18 bytes) separated by few literals (<= 14 bytes).
|
|
* this shortcut was tested on x86 and x64, where it improves decoding speed.
|
|
* it has not yet been benchmarked on ARM, Power, mips, etc. */
|
|
if (((ip + 14 /*maxLL*/ + 2 /*offset*/ <= iend)
|
|
& (op + 14 /*maxLL*/ + 18 /*maxML*/ <= oend))
|
|
& ((token < (15<<ML_BITS)) & ((token & ML_MASK) != 15)) ) {
|
|
size_t const ll = token >> ML_BITS;
|
|
size_t const off = LZ4_readLE16(ip+ll);
|
|
const BYTE* const matchPtr = op + ll - off; /* pointer underflow risk ? */
|
|
if ((off >= 8) /* do not deal with overlapping matches */ & (matchPtr >= lowPrefix)) {
|
|
size_t const ml = (token & ML_MASK) + MINMATCH;
|
|
memcpy(op, ip, 16); op += ll; ip += ll + 2 /*offset*/;
|
|
memcpy(op + 0, matchPtr + 0, 8);
|
|
memcpy(op + 8, matchPtr + 8, 8);
|
|
memcpy(op +16, matchPtr +16, 2);
|
|
op += ml;
|
|
continue;
|
|
}
|
|
}
|
|
|
|
/* decode literal length */
|
|
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 + dictSize < lowPrefix))) 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)) {
|
|
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];
|
|
} else { memcpy(op, match, 8); 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 {
|
|
memcpy(op, match, 8);
|
|
if (length>16) LZ4_wildCopy(op+8, match+8, cpy);
|
|
}
|
|
op = cpy; /* correction */
|
|
}
|
|
|
|
/* 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 */
|
|
|
|
/* Overflow error detected */
|
|
_output_error:
|
|
return (int) (-(((const char*)ip)-src))-1;
|
|
}
|
|
|
|
|
|
LZ4_FORCE_O2_GCC_PPC64LE
|
|
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);
|
|
}
|
|
|
|
LZ4_FORCE_O2_GCC_PPC64LE
|
|
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);
|
|
}
|
|
|
|
LZ4_FORCE_O2_GCC_PPC64LE
|
|
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 =====*/
|
|
|
|
LZ4_streamDecode_t* LZ4_createStreamDecode(void)
|
|
{
|
|
LZ4_streamDecode_t* lz4s = (LZ4_streamDecode_t*) ALLOC_AND_ZERO(sizeof(LZ4_streamDecode_t));
|
|
return lz4s;
|
|
}
|
|
|
|
int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream)
|
|
{
|
|
if (!LZ4_stream) return 0; /* support free on NULL */
|
|
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()
|
|
*/
|
|
LZ4_FORCE_O2_GCC_PPC64LE
|
|
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;
|
|
}
|
|
|
|
LZ4_FORCE_O2_GCC_PPC64LE
|
|
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
|
|
*/
|
|
|
|
LZ4_FORCE_O2_GCC_PPC64LE
|
|
LZ4_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);
|
|
}
|
|
|
|
LZ4_FORCE_O2_GCC_PPC64LE
|
|
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);
|
|
}
|
|
|
|
LZ4_FORCE_O2_GCC_PPC64LE
|
|
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 */
|
|
LZ4_FORCE_O2_GCC_PPC64LE
|
|
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; }
|
|
|
|
int LZ4_resetStreamState(void* state, char* inputBuffer)
|
|
{
|
|
(void)inputBuffer;
|
|
LZ4_resetStream((LZ4_stream_t*)state);
|
|
return 0;
|
|
}
|
|
|
|
void* LZ4_create (char* inputBuffer)
|
|
{
|
|
(void)inputBuffer;
|
|
return LZ4_createStream();
|
|
}
|
|
|
|
char* LZ4_slideInputBuffer (void* state)
|
|
{
|
|
/* avoid const char * -> char * conversion warning */
|
|
return (char *)(uptrval)((LZ4_stream_t*)state)->internal_donotuse.dictionary;
|
|
}
|
|
|
|
/* 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 */
|