6010 lines
248 KiB
C
6010 lines
248 KiB
C
/*
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LZ4 - Fast LZ compression algorithm
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Copyright (C) 2011-present, Yann Collet.
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BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
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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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* LZ4_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 LZ4_ACCELERATION_DEFAULT 1
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/*
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* LZ4_ACCELERATION_MAX :
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* Any "acceleration" value higher than this threshold
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* get treated as LZ4_ACCELERATION_MAX instead (fix #876)
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*/
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#define LZ4_ACCELERATION_MAX 65537
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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__) && \
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( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) \
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|| 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 WinCE doesn't support Hardware bit count */
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# undef LZ4_FORCE_SW_BITCOUNT /* avoid double def */
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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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/*
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* LZ4_SRC_INCLUDED:
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* Amalgamation flag, whether lz4.c is included
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*/
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#ifndef LZ4_SRC_INCLUDED
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# define LZ4_SRC_INCLUDED 1
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#endif
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#ifndef LZ4_STATIC_LINKING_ONLY
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#define LZ4_STATIC_LINKING_ONLY
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#endif
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#ifndef LZ4_DISABLE_DEPRECATE_WARNINGS
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#define LZ4_DISABLE_DEPRECATE_WARNINGS /* due to LZ4_decompress_safe_withPrefix64k */
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#endif
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#define LZ4_STATIC_LINKING_ONLY /* LZ4_DISTANCE_MAX */
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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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#if defined(_MSC_VER) && (_MSC_VER >= 1400) /* Visual Studio 2005+ */
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# include <intrin.h> /* only present in VS2005+ */
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# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
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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 and LZ4_FORCE_INLINE
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* gcc on ppc64le generates an unrolled SIMDized loop for LZ4_wildCopy8,
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* together with a simple 8-byte copy loop as a fall-back path.
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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_wildCopy8
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* functions are annotated with __attribute__((optimize("O2"))),
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* and also LZ4_wildCopy8 is forcibly inlined, so that the O2 attribute
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* of LZ4_wildCopy8 does not affect the compression speed.
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*/
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#if defined(__PPC64__) && defined(__LITTLE_ENDIAN__) && defined(__GNUC__) && !defined(__clang__)
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# define LZ4_FORCE_O2 __attribute__((optimize("O2")))
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# undef LZ4_FORCE_INLINE
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# define LZ4_FORCE_INLINE static __inline __attribute__((optimize("O2"),always_inline))
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#else
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# define LZ4_FORCE_O2
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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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#ifndef likely
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#define likely(expr) expect((expr) != 0, 1)
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#endif
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#ifndef unlikely
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#define unlikely(expr) expect((expr) != 0, 0)
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#endif
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/* Should the alignment test prove unreliable, for some reason,
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* it can be disabled by setting LZ4_ALIGN_TEST to 0 */
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#ifndef LZ4_ALIGN_TEST /* can be externally provided */
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# define LZ4_ALIGN_TEST 1
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#endif
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/*-************************************
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* Memory routines
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**************************************/
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#ifdef LZ4_USER_MEMORY_FUNCTIONS
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/* memory management functions can be customized by user project.
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* Below functions must exist somewhere in the Project
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* and be available at link time */
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void* LZ4_malloc(size_t s);
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void* LZ4_calloc(size_t n, size_t s);
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void LZ4_free(void* p);
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# define ALLOC(s) LZ4_malloc(s)
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# define ALLOC_AND_ZERO(s) LZ4_calloc(1,s)
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# define FREEMEM(p) LZ4_free(p)
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#else
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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(p) free(p)
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#endif
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#include <string.h> /* memset, memcpy */
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#define MEM_INIT(p,v,s) memset((p),(v),(s))
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/*-************************************
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* 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 /* see ../doc/lz4_Block_format.md#parsing-restrictions */
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#define MFLIMIT 12 /* see ../doc/lz4_Block_format.md#parsing-restrictions */
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#define MATCH_SAFEGUARD_DISTANCE ((2*WILDCOPYLENGTH) - MINMATCH) /* ensure it's possible to write 2 x wildcopyLength without overflowing output buffer */
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#define FASTLOOP_SAFE_DISTANCE 64
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static const int LZ4_minLength = (MFLIMIT+1);
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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 LZ4_DISTANCE_ABSOLUTE_MAX 65535
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#if (LZ4_DISTANCE_MAX > LZ4_DISTANCE_ABSOLUTE_MAX) /* max supported by LZ4 format */
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# error "LZ4_DISTANCE_MAX is too big : must be <= 65535"
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#endif
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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 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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static int LZ4_isAligned(const void* ptr, size_t alignment)
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{
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return ((size_t)ptr & (alignment -1)) == 0;
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}
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/*-************************************
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* Types
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**************************************/
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#include <limits.h>
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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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# if UINT_MAX != 4294967295UL
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# error "LZ4 code (when not C++ or C99) assumes that sizeof(int) == 4"
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# endif
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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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typedef enum {
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notLimited = 0,
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limitedOutput = 1,
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fillOutput = 2
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} limitedOutput_directive;
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/*-************************************
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* Reading and writing into memory
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**************************************/
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/**
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* LZ4 relies on memcpy with a constant size being inlined. In freestanding
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* environments, the compiler can't assume the implementation of memcpy() is
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* standard compliant, so it can't apply its specialized memcpy() inlining
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* logic. When possible, use __builtin_memcpy() to tell the compiler to analyze
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* memcpy() as if it were standard compliant, so it can inline it in freestanding
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* environments. This is needed when decompressing the Linux Kernel, for example.
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*/
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#if defined(__GNUC__) && (__GNUC__ >= 4)
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#define LZ4_memcpy(dst, src, size) __builtin_memcpy(dst, src, size)
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#else
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#define LZ4_memcpy(dst, src, size) memcpy(dst, src, size)
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#endif
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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 using memcpy() */
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static U16 LZ4_read16(const void* memPtr)
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{
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U16 val; LZ4_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; LZ4_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; LZ4_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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LZ4_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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LZ4_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_INLINE
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void LZ4_wildCopy8(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_memcpy(d,s,8); d+=8; s+=8; } while (d<e);
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}
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static const unsigned inc32table[8] = {0, 1, 2, 1, 0, 4, 4, 4};
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static const int dec64table[8] = {0, 0, 0, -1, -4, 1, 2, 3};
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#ifndef LZ4_FAST_DEC_LOOP
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# if defined __i386__ || defined _M_IX86 || defined __x86_64__ || defined _M_X64
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# define LZ4_FAST_DEC_LOOP 1
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# elif defined(__aarch64__) && !defined(__clang__)
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/* On aarch64, we disable this optimization for clang because on certain
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* mobile chipsets, performance is reduced with clang. For information
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* refer to https://github.com/lz4/lz4/pull/707 */
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# define LZ4_FAST_DEC_LOOP 1
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# else
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# define LZ4_FAST_DEC_LOOP 0
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# endif
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#endif
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#if LZ4_FAST_DEC_LOOP
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LZ4_FORCE_INLINE void
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LZ4_memcpy_using_offset_base(BYTE* dstPtr, const BYTE* srcPtr, BYTE* dstEnd, const size_t offset)
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{
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assert(srcPtr + offset == dstPtr);
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if (offset < 8) {
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LZ4_write32(dstPtr, 0); /* silence an msan warning when offset==0 */
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dstPtr[0] = srcPtr[0];
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dstPtr[1] = srcPtr[1];
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dstPtr[2] = srcPtr[2];
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dstPtr[3] = srcPtr[3];
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srcPtr += inc32table[offset];
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LZ4_memcpy(dstPtr+4, srcPtr, 4);
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srcPtr -= dec64table[offset];
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dstPtr += 8;
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} else {
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LZ4_memcpy(dstPtr, srcPtr, 8);
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dstPtr += 8;
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srcPtr += 8;
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}
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LZ4_wildCopy8(dstPtr, srcPtr, dstEnd);
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}
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/* customized variant of memcpy, which can overwrite up to 32 bytes beyond dstEnd
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* this version copies two times 16 bytes (instead of one time 32 bytes)
|
|
* because it must be compatible with offsets >= 16. */
|
|
LZ4_FORCE_INLINE void
|
|
LZ4_wildCopy32(void* dstPtr, const void* srcPtr, void* dstEnd)
|
|
{
|
|
BYTE* d = (BYTE*)dstPtr;
|
|
const BYTE* s = (const BYTE*)srcPtr;
|
|
BYTE* const e = (BYTE*)dstEnd;
|
|
|
|
do { LZ4_memcpy(d,s,16); LZ4_memcpy(d+16,s+16,16); d+=32; s+=32; } while (d<e);
|
|
}
|
|
|
|
/* LZ4_memcpy_using_offset() presumes :
|
|
* - dstEnd >= dstPtr + MINMATCH
|
|
* - there is at least 8 bytes available to write after dstEnd */
|
|
LZ4_FORCE_INLINE void
|
|
LZ4_memcpy_using_offset(BYTE* dstPtr, const BYTE* srcPtr, BYTE* dstEnd, const size_t offset)
|
|
{
|
|
BYTE v[8];
|
|
|
|
assert(dstEnd >= dstPtr + MINMATCH);
|
|
|
|
switch(offset) {
|
|
case 1:
|
|
MEM_INIT(v, *srcPtr, 8);
|
|
break;
|
|
case 2:
|
|
LZ4_memcpy(v, srcPtr, 2);
|
|
LZ4_memcpy(&v[2], srcPtr, 2);
|
|
LZ4_memcpy(&v[4], v, 4);
|
|
break;
|
|
case 4:
|
|
LZ4_memcpy(v, srcPtr, 4);
|
|
LZ4_memcpy(&v[4], srcPtr, 4);
|
|
break;
|
|
default:
|
|
LZ4_memcpy_using_offset_base(dstPtr, srcPtr, dstEnd, offset);
|
|
return;
|
|
}
|
|
|
|
LZ4_memcpy(dstPtr, v, 8);
|
|
dstPtr += 8;
|
|
while (dstPtr < dstEnd) {
|
|
LZ4_memcpy(dstPtr, v, 8);
|
|
dstPtr += 8;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
|
|
/*-************************************
|
|
* Common functions
|
|
**************************************/
|
|
static unsigned LZ4_NbCommonBytes (reg_t val)
|
|
{
|
|
assert(val != 0);
|
|
if (LZ4_isLittleEndian()) {
|
|
if (sizeof(val) == 8) {
|
|
# if defined(_MSC_VER) && (_MSC_VER >= 1800) && defined(_M_AMD64) && !defined(LZ4_FORCE_SW_BITCOUNT)
|
|
/* x64 CPUS without BMI support interpret `TZCNT` as `REP BSF` */
|
|
return (unsigned)_tzcnt_u64(val) >> 3;
|
|
# elif defined(_MSC_VER) && defined(_WIN64) && !defined(LZ4_FORCE_SW_BITCOUNT)
|
|
unsigned long r = 0;
|
|
_BitScanForward64(&r, (U64)val);
|
|
return (unsigned)r >> 3;
|
|
# elif (defined(__clang__) || (defined(__GNUC__) && ((__GNUC__ > 3) || \
|
|
((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4))))) && \
|
|
!defined(LZ4_FORCE_SW_BITCOUNT)
|
|
return (unsigned)__builtin_ctzll((U64)val) >> 3;
|
|
# else
|
|
const U64 m = 0x0101010101010101ULL;
|
|
val ^= val - 1;
|
|
return (unsigned)(((U64)((val & (m - 1)) * m)) >> 56);
|
|
# endif
|
|
} else /* 32 bits */ {
|
|
# if defined(_MSC_VER) && (_MSC_VER >= 1400) && !defined(LZ4_FORCE_SW_BITCOUNT)
|
|
unsigned long r;
|
|
_BitScanForward(&r, (U32)val);
|
|
return (unsigned)r >> 3;
|
|
# elif (defined(__clang__) || (defined(__GNUC__) && ((__GNUC__ > 3) || \
|
|
((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4))))) && \
|
|
!defined(__TINYC__) && !defined(LZ4_FORCE_SW_BITCOUNT)
|
|
return (unsigned)__builtin_ctz((U32)val) >> 3;
|
|
# else
|
|
const U32 m = 0x01010101;
|
|
return (unsigned)((((val - 1) ^ val) & (m - 1)) * m) >> 24;
|
|
# endif
|
|
}
|
|
} else /* Big Endian CPU */ {
|
|
if (sizeof(val)==8) {
|
|
# if (defined(__clang__) || (defined(__GNUC__) && ((__GNUC__ > 3) || \
|
|
((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4))))) && \
|
|
!defined(__TINYC__) && !defined(LZ4_FORCE_SW_BITCOUNT)
|
|
return (unsigned)__builtin_clzll((U64)val) >> 3;
|
|
# else
|
|
#if 1
|
|
/* this method is probably faster,
|
|
* but adds a 128 bytes lookup table */
|
|
static const unsigned char ctz7_tab[128] = {
|
|
7, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
|
|
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
|
|
5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
|
|
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
|
|
6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
|
|
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
|
|
5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
|
|
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
|
|
};
|
|
U64 const mask = 0x0101010101010101ULL;
|
|
U64 const t = (((val >> 8) - mask) | val) & mask;
|
|
return ctz7_tab[(t * 0x0080402010080402ULL) >> 57];
|
|
#else
|
|
/* this method doesn't consume memory space like the previous one,
|
|
* but it contains several branches,
|
|
* that may end up slowing execution */
|
|
static const U32 by32 = sizeof(val)*4; /* 32 on 64 bits (goal), 16 on 32 bits.
|
|
Just to avoid some static analyzer complaining about shift by 32 on 32-bits target.
|
|
Note that this code path is never triggered in 32-bits mode. */
|
|
unsigned r;
|
|
if (!(val>>by32)) { r=4; } else { r=0; val>>=by32; }
|
|
if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
|
|
r += (!val);
|
|
return r;
|
|
#endif
|
|
# endif
|
|
} else /* 32 bits */ {
|
|
# if (defined(__clang__) || (defined(__GNUC__) && ((__GNUC__ > 3) || \
|
|
((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4))))) && \
|
|
!defined(LZ4_FORCE_SW_BITCOUNT)
|
|
return (unsigned)__builtin_clz((U32)val) >> 3;
|
|
# else
|
|
val >>= 8;
|
|
val = ((((val + 0x00FFFF00) | 0x00FFFFFF) + val) |
|
|
(val + 0x00FF0000)) >> 24;
|
|
return (unsigned)val ^ 3;
|
|
# endif
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
#define STEPSIZE sizeof(reg_t)
|
|
LZ4_FORCE_INLINE
|
|
unsigned LZ4_count(const BYTE* pIn, const BYTE* pMatch, const BYTE* pInLimit)
|
|
{
|
|
const BYTE* const pStart = pIn;
|
|
|
|
if (likely(pIn < pInLimit-(STEPSIZE-1))) {
|
|
reg_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn);
|
|
if (!diff) {
|
|
pIn+=STEPSIZE; pMatch+=STEPSIZE;
|
|
} else {
|
|
return LZ4_NbCommonBytes(diff);
|
|
} }
|
|
|
|
while (likely(pIn < pInLimit-(STEPSIZE-1))) {
|
|
reg_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn);
|
|
if (!diff) { pIn+=STEPSIZE; pMatch+=STEPSIZE; continue; }
|
|
pIn += LZ4_NbCommonBytes(diff);
|
|
return (unsigned)(pIn - pStart);
|
|
}
|
|
|
|
if ((STEPSIZE==8) && (pIn<(pInLimit-3)) && (LZ4_read32(pMatch) == LZ4_read32(pIn))) { pIn+=4; pMatch+=4; }
|
|
if ((pIn<(pInLimit-1)) && (LZ4_read16(pMatch) == LZ4_read16(pIn))) { pIn+=2; pMatch+=2; }
|
|
if ((pIn<pInLimit) && (*pMatch == *pIn)) pIn++;
|
|
return (unsigned)(pIn - pStart);
|
|
}
|
|
|
|
|
|
#ifndef LZ4_COMMONDEFS_ONLY
|
|
/*-************************************
|
|
* Local Constants
|
|
**************************************/
|
|
static const int LZ4_64Klimit = ((64 KB) + (MFLIMIT-1));
|
|
static const U32 LZ4_skipTrigger = 6; /* Increase this value ==> compression run slower on incompressible data */
|
|
|
|
|
|
/*-************************************
|
|
* Local Structures and types
|
|
**************************************/
|
|
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;
|
|
|
|
|
|
/*-************************************
|
|
* 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(void) { return LZ4_STREAMSIZE; }
|
|
|
|
|
|
/*-************************************
|
|
* Internal Definitions used in Tests
|
|
**************************************/
|
|
#if defined (__cplusplus)
|
|
extern "C" {
|
|
#endif
|
|
|
|
int LZ4_compress_forceExtDict (LZ4_stream_t* LZ4_dict, const char* source, char* dest, int srcSize);
|
|
|
|
int LZ4_decompress_safe_forceExtDict(const char* source, char* dest,
|
|
int compressedSize, int maxOutputSize,
|
|
const void* dictStart, size_t dictSize);
|
|
|
|
#if defined (__cplusplus)
|
|
}
|
|
#endif
|
|
|
|
/*-******************************
|
|
* Compression functions
|
|
********************************/
|
|
LZ4_FORCE_INLINE 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));
|
|
}
|
|
|
|
LZ4_FORCE_INLINE U32 LZ4_hash5(U64 sequence, tableType_t const tableType)
|
|
{
|
|
const U32 hashLog = (tableType == byU16) ? LZ4_HASHLOG+1 : LZ4_HASHLOG;
|
|
if (LZ4_isLittleEndian()) {
|
|
const U64 prime5bytes = 889523592379ULL;
|
|
return (U32)(((sequence << 24) * prime5bytes) >> (64 - hashLog));
|
|
} else {
|
|
const U64 prime8bytes = 11400714785074694791ULL;
|
|
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);
|
|
}
|
|
|
|
LZ4_FORCE_INLINE void LZ4_clearHash(U32 h, void* tableBase, tableType_t const tableType)
|
|
{
|
|
switch (tableType)
|
|
{
|
|
default: /* fallthrough */
|
|
case clearedTable: { /* illegal! */ assert(0); return; }
|
|
case byPtr: { const BYTE** hashTable = (const BYTE**)tableBase; hashTable[h] = NULL; return; }
|
|
case byU32: { U32* hashTable = (U32*) tableBase; hashTable[h] = 0; return; }
|
|
case byU16: { U16* hashTable = (U16*) tableBase; hashTable[h] = 0; return; }
|
|
}
|
|
}
|
|
|
|
LZ4_FORCE_INLINE 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; }
|
|
}
|
|
}
|
|
|
|
LZ4_FORCE_INLINE 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)
|
|
*/
|
|
LZ4_FORCE_INLINE 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 ((tableType_t)cctx->tableType != clearedTable) {
|
|
assert(inputSize >= 0);
|
|
if ((tableType_t)cctx->tableType != tableType
|
|
|| ((tableType == byU16) && cctx->currentOffset + (unsigned)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 = (U32)clearedTable;
|
|
} else {
|
|
DEBUGLOG(4, "LZ4_prepareTable: Re-use hash table (no reset)");
|
|
}
|
|
}
|
|
|
|
/* Adding a gap, so all previous entries are > LZ4_DISTANCE_MAX 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.
|
|
* Presumed already validated at this stage:
|
|
* - source != NULL
|
|
* - inputSize > 0
|
|
*/
|
|
LZ4_FORCE_INLINE int LZ4_compress_generic_validated(
|
|
LZ4_stream_t_internal* const cctx,
|
|
const char* const source,
|
|
char* const dest,
|
|
const int inputSize,
|
|
int *inputConsumed, /* only written when outputDirective == fillOutput */
|
|
const int maxOutputSize,
|
|
const limitedOutput_directive outputDirective,
|
|
const tableType_t tableType,
|
|
const dict_directive dictDirective,
|
|
const dictIssue_directive dictIssue,
|
|
const int acceleration)
|
|
{
|
|
int result;
|
|
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 ? dictionary + dictSize : dictionary;
|
|
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 = !dictionary ? NULL : (dictDirective == usingDictCtx) ?
|
|
dictionary + dictSize - dictCtx->currentOffset :
|
|
dictionary + dictSize - startIndex;
|
|
|
|
BYTE* op = (BYTE*) dest;
|
|
BYTE* const olimit = op + maxOutputSize;
|
|
|
|
U32 offset = 0;
|
|
U32 forwardH;
|
|
|
|
DEBUGLOG(5, "LZ4_compress_generic_validated: srcSize=%i, tableType=%u", inputSize, tableType);
|
|
assert(ip != NULL);
|
|
/* If init conditions are not met, we don't have to mark stream
|
|
* as having dirty context, since no action was taken yet */
|
|
if (outputDirective == fillOutput && maxOutputSize < 1) { return 0; } /* Impossible to store anything */
|
|
if ((tableType == byU16) && (inputSize>=LZ4_64Klimit)) { return 0; } /* Size too large (not within 64K limit) */
|
|
if (tableType==byPtr) assert(dictDirective==noDict); /* only supported use case with byPtr */
|
|
assert(acceleration >= 1);
|
|
|
|
lowLimit = (const BYTE*)source - (dictDirective == withPrefix64k ? dictSize : 0);
|
|
|
|
/* Update context state */
|
|
if (dictDirective == usingDictCtx) {
|
|
/* Subsequent linked blocks can't use the dictionary. */
|
|
/* Instead, they use the block we just compressed. */
|
|
cctx->dictCtx = NULL;
|
|
cctx->dictSize = (U32)inputSize;
|
|
} else {
|
|
cctx->dictSize += (U32)inputSize;
|
|
}
|
|
cctx->currentOffset += (U32)inputSize;
|
|
cctx->tableType = (U32)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;
|
|
const BYTE* filledIp;
|
|
|
|
/* Find a match */
|
|
if (tableType == byPtr) {
|
|
const BYTE* forwardIp = ip;
|
|
int step = 1;
|
|
int 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+LZ4_DISTANCE_MAX < ip)
|
|
|| (LZ4_read32(match) != LZ4_read32(ip)) );
|
|
|
|
} else { /* byU32, byU16 */
|
|
|
|
const BYTE* forwardIp = ip;
|
|
int step = 1;
|
|
int 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);
|
|
assert(startIndex - matchIndex >= MINMATCH);
|
|
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);
|
|
|
|
DEBUGLOG(7, "candidate at pos=%u (offset=%u \n", matchIndex, current - matchIndex);
|
|
if ((dictIssue == dictSmall) && (matchIndex < prefixIdxLimit)) { continue; } /* match outside of valid area */
|
|
assert(matchIndex < current);
|
|
if ( ((tableType != byU16) || (LZ4_DISTANCE_MAX < LZ4_DISTANCE_ABSOLUTE_MAX))
|
|
&& (matchIndex+LZ4_DISTANCE_MAX < current)) {
|
|
continue;
|
|
} /* too far */
|
|
assert((current - matchIndex) <= LZ4_DISTANCE_MAX); /* match now expected within distance */
|
|
|
|
if (LZ4_read32(match) == LZ4_read32(ip)) {
|
|
if (maybe_extMem) offset = current - matchIndex;
|
|
break; /* match found */
|
|
}
|
|
|
|
} while(1);
|
|
}
|
|
|
|
/* Catch up */
|
|
filledIp = ip;
|
|
while (((ip>anchor) & (match > lowLimit)) && (unlikely(ip[-1]==match[-1]))) { ip--; match--; }
|
|
|
|
/* Encode Literals */
|
|
{ unsigned const litLength = (unsigned)(ip - anchor);
|
|
token = op++;
|
|
if ((outputDirective == limitedOutput) && /* Check output buffer overflow */
|
|
(unlikely(op + litLength + (2 + 1 + LASTLITERALS) + (litLength/255) > olimit)) ) {
|
|
return 0; /* cannot compress within `dst` budget. Stored indexes in hash table are nonetheless fine */
|
|
}
|
|
if ((outputDirective == fillOutput) &&
|
|
(unlikely(op + (litLength+240)/255 /* litlen */ + litLength /* literals */ + 2 /* offset */ + 1 /* token */ + MFLIMIT - MINMATCH /* min last literals so last match is <= end - MFLIMIT */ > olimit))) {
|
|
op--;
|
|
goto _last_literals;
|
|
}
|
|
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_wildCopy8(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
|
|
*/
|
|
|
|
if ((outputDirective == fillOutput) &&
|
|
(op + 2 /* offset */ + 1 /* token */ + MFLIMIT - MINMATCH /* min last literals so last match is <= end - MFLIMIT */ > olimit)) {
|
|
/* the match was too close to the end, rewind and go to last literals */
|
|
op = token;
|
|
goto _last_literals;
|
|
}
|
|
|
|
/* Encode Offset */
|
|
if (maybe_extMem) { /* static test */
|
|
DEBUGLOG(6, " with offset=%u (ext if > %i)", offset, (int)(ip - (const BYTE*)source));
|
|
assert(offset <= LZ4_DISTANCE_MAX && offset > 0);
|
|
LZ4_writeLE16(op, (U16)offset); op+=2;
|
|
} else {
|
|
DEBUGLOG(6, " with offset=%u (same segment)", (U32)(ip - match));
|
|
assert(ip-match <= LZ4_DISTANCE_MAX);
|
|
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 += (size_t)matchCode + MINMATCH;
|
|
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 += (size_t)matchCode + MINMATCH;
|
|
DEBUGLOG(6, " with matchLength=%u", matchCode+MINMATCH);
|
|
}
|
|
|
|
if ((outputDirective) && /* Check output buffer overflow */
|
|
(unlikely(op + (1 + LASTLITERALS) + (matchCode+240)/255 > olimit)) ) {
|
|
if (outputDirective == fillOutput) {
|
|
/* Match description too long : reduce it */
|
|
U32 newMatchCode = 15 /* in token */ - 1 /* to avoid needing a zero byte */ + ((U32)(olimit - op) - 1 - LASTLITERALS) * 255;
|
|
ip -= matchCode - newMatchCode;
|
|
assert(newMatchCode < matchCode);
|
|
matchCode = newMatchCode;
|
|
if (unlikely(ip <= filledIp)) {
|
|
/* We have already filled up to filledIp so if ip ends up less than filledIp
|
|
* we have positions in the hash table beyond the current position. This is
|
|
* a problem if we reuse the hash table. So we have to remove these positions
|
|
* from the hash table.
|
|
*/
|
|
const BYTE* ptr;
|
|
DEBUGLOG(5, "Clearing %u positions", (U32)(filledIp - ip));
|
|
for (ptr = ip; ptr <= filledIp; ++ptr) {
|
|
U32 const h = LZ4_hashPosition(ptr, tableType);
|
|
LZ4_clearHash(h, cctx->hashTable, tableType);
|
|
}
|
|
}
|
|
} else {
|
|
assert(outputDirective == limitedOutput);
|
|
return 0; /* cannot compress within `dst` budget. Stored indexes in hash table are nonetheless fine */
|
|
}
|
|
}
|
|
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);
|
|
}
|
|
/* Ensure we have enough space for the last literals. */
|
|
assert(!(outputDirective == fillOutput && op + 1 + LASTLITERALS > olimit));
|
|
|
|
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+LZ4_DISTANCE_MAX >= 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);
|
|
assert(matchIndex < current);
|
|
if ( ((dictIssue==dictSmall) ? (matchIndex >= prefixIdxLimit) : 1)
|
|
&& (((tableType==byU16) && (LZ4_DISTANCE_MAX == LZ4_DISTANCE_ABSOLUTE_MAX)) ? 1 : (matchIndex+LZ4_DISTANCE_MAX >= current))
|
|
&& (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 lastRun = (size_t)(iend - anchor);
|
|
if ( (outputDirective) && /* Check output buffer overflow */
|
|
(op + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > olimit)) {
|
|
if (outputDirective == fillOutput) {
|
|
/* adapt lastRun to fill 'dst' */
|
|
assert(olimit >= op);
|
|
lastRun = (size_t)(olimit-op) - 1/*token*/;
|
|
lastRun -= (lastRun + 256 - RUN_MASK) / 256; /*additional length tokens*/
|
|
} else {
|
|
assert(outputDirective == limitedOutput);
|
|
return 0; /* cannot compress within `dst` budget. Stored indexes in hash table are nonetheless fine */
|
|
}
|
|
}
|
|
DEBUGLOG(6, "Final literal run : %i literals", (int)lastRun);
|
|
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);
|
|
}
|
|
LZ4_memcpy(op, anchor, lastRun);
|
|
ip = anchor + lastRun;
|
|
op += lastRun;
|
|
}
|
|
|
|
if (outputDirective == fillOutput) {
|
|
*inputConsumed = (int) (((const char*)ip)-source);
|
|
}
|
|
result = (int)(((char*)op) - dest);
|
|
assert(result > 0);
|
|
DEBUGLOG(5, "LZ4_compress_generic: compressed %i bytes into %i bytes", inputSize, result);
|
|
return result;
|
|
}
|
|
|
|
/** LZ4_compress_generic() :
|
|
* inlined, to ensure branches are decided at compilation time;
|
|
* takes care of src == (NULL, 0)
|
|
* and forward the rest to LZ4_compress_generic_validated */
|
|
LZ4_FORCE_INLINE int LZ4_compress_generic(
|
|
LZ4_stream_t_internal* const cctx,
|
|
const char* const src,
|
|
char* const dst,
|
|
const int srcSize,
|
|
int *inputConsumed, /* only written when outputDirective == fillOutput */
|
|
const int dstCapacity,
|
|
const limitedOutput_directive outputDirective,
|
|
const tableType_t tableType,
|
|
const dict_directive dictDirective,
|
|
const dictIssue_directive dictIssue,
|
|
const int acceleration)
|
|
{
|
|
DEBUGLOG(5, "LZ4_compress_generic: srcSize=%i, dstCapacity=%i",
|
|
srcSize, dstCapacity);
|
|
|
|
if ((U32)srcSize > (U32)LZ4_MAX_INPUT_SIZE) { return 0; } /* Unsupported srcSize, too large (or negative) */
|
|
if (srcSize == 0) { /* src == NULL supported if srcSize == 0 */
|
|
if (outputDirective != notLimited && dstCapacity <= 0) return 0; /* no output, can't write anything */
|
|
DEBUGLOG(5, "Generating an empty block");
|
|
assert(outputDirective == notLimited || dstCapacity >= 1);
|
|
assert(dst != NULL);
|
|
dst[0] = 0;
|
|
if (outputDirective == fillOutput) {
|
|
assert (inputConsumed != NULL);
|
|
*inputConsumed = 0;
|
|
}
|
|
return 1;
|
|
}
|
|
assert(src != NULL);
|
|
|
|
return LZ4_compress_generic_validated(cctx, src, dst, srcSize,
|
|
inputConsumed, /* only written into if outputDirective == fillOutput */
|
|
dstCapacity, outputDirective,
|
|
tableType, dictDirective, dictIssue, acceleration);
|
|
}
|
|
|
|
|
|
int LZ4_compress_fast_extState(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration)
|
|
{
|
|
LZ4_stream_t_internal* const ctx = & LZ4_initStream(state, sizeof(LZ4_stream_t)) -> internal_donotuse;
|
|
assert(ctx != NULL);
|
|
if (acceleration < 1) acceleration = LZ4_ACCELERATION_DEFAULT;
|
|
if (acceleration > LZ4_ACCELERATION_MAX) acceleration = LZ4_ACCELERATION_MAX;
|
|
if (maxOutputSize >= LZ4_compressBound(inputSize)) {
|
|
if (inputSize < LZ4_64Klimit) {
|
|
return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, 0, notLimited, byU16, noDict, noDictIssue, acceleration);
|
|
} else {
|
|
const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)source > LZ4_DISTANCE_MAX)) ? byPtr : byU32;
|
|
return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, 0, notLimited, tableType, noDict, noDictIssue, acceleration);
|
|
}
|
|
} else {
|
|
if (inputSize < LZ4_64Klimit) {
|
|
return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue, acceleration);
|
|
} else {
|
|
const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)source > LZ4_DISTANCE_MAX)) ? byPtr : byU32;
|
|
return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, noDict, noDictIssue, acceleration);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* LZ4_compress_fast_extState_fastReset() :
|
|
* A variant of LZ4_compress_fast_extState().
|
|
*
|
|
* Using this variant avoids an expensive initialization step. It is only safe
|
|
* to call if the state buffer is known to be correctly initialized already
|
|
* (see comment in lz4.h on LZ4_resetStream_fast() for a definition of
|
|
* "correctly initialized").
|
|
*/
|
|
int LZ4_compress_fast_extState_fastReset(void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration)
|
|
{
|
|
LZ4_stream_t_internal* ctx = &((LZ4_stream_t*)state)->internal_donotuse;
|
|
if (acceleration < 1) acceleration = LZ4_ACCELERATION_DEFAULT;
|
|
if (acceleration > LZ4_ACCELERATION_MAX) acceleration = LZ4_ACCELERATION_MAX;
|
|
|
|
if (dstCapacity >= LZ4_compressBound(srcSize)) {
|
|
if (srcSize < LZ4_64Klimit) {
|
|
const tableType_t tableType = byU16;
|
|
LZ4_prepareTable(ctx, srcSize, tableType);
|
|
if (ctx->currentOffset) {
|
|
return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 0, notLimited, tableType, noDict, dictSmall, acceleration);
|
|
} else {
|
|
return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 0, notLimited, tableType, noDict, noDictIssue, acceleration);
|
|
}
|
|
} else {
|
|
const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)src > LZ4_DISTANCE_MAX)) ? byPtr : byU32;
|
|
LZ4_prepareTable(ctx, srcSize, tableType);
|
|
return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 0, notLimited, tableType, noDict, noDictIssue, acceleration);
|
|
}
|
|
} else {
|
|
if (srcSize < LZ4_64Klimit) {
|
|
const tableType_t tableType = byU16;
|
|
LZ4_prepareTable(ctx, srcSize, tableType);
|
|
if (ctx->currentOffset) {
|
|
return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, dstCapacity, limitedOutput, tableType, noDict, dictSmall, acceleration);
|
|
} else {
|
|
return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, dstCapacity, limitedOutput, tableType, noDict, noDictIssue, acceleration);
|
|
}
|
|
} else {
|
|
const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)src > LZ4_DISTANCE_MAX)) ? byPtr : byU32;
|
|
LZ4_prepareTable(ctx, srcSize, tableType);
|
|
return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 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* src, char* dst, int srcSize, int maxOutputSize)
|
|
{
|
|
return LZ4_compress_fast(src, dst, srcSize, maxOutputSize, 1);
|
|
}
|
|
|
|
|
|
/* Note!: This function leaves the stream in an unclean/broken state!
|
|
* It is not safe to subsequently use the same state with a _fastReset() or
|
|
* _continue() call without resetting it. */
|
|
static int LZ4_compress_destSize_extState (LZ4_stream_t* state, const char* src, char* dst, int* srcSizePtr, int targetDstSize)
|
|
{
|
|
void* const s = LZ4_initStream(state, sizeof (*state));
|
|
assert(s != NULL); (void)s;
|
|
|
|
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_generic(&state->internal_donotuse, src, dst, *srcSizePtr, srcSizePtr, targetDstSize, fillOutput, byU16, noDict, noDictIssue, 1);
|
|
} else {
|
|
tableType_t const addrMode = ((sizeof(void*)==4) && ((uptrval)src > LZ4_DISTANCE_MAX)) ? byPtr : byU32;
|
|
return LZ4_compress_generic(&state->internal_donotuse, src, dst, *srcSizePtr, srcSizePtr, targetDstSize, fillOutput, addrMode, noDict, noDictIssue, 1);
|
|
} }
|
|
}
|
|
|
|
|
|
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* const 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_initStream(lz4s, sizeof(*lz4s));
|
|
return lz4s;
|
|
}
|
|
|
|
static size_t LZ4_stream_t_alignment(void)
|
|
{
|
|
#if LZ4_ALIGN_TEST
|
|
typedef struct { char c; LZ4_stream_t t; } t_a;
|
|
return sizeof(t_a) - sizeof(LZ4_stream_t);
|
|
#else
|
|
return 1; /* effectively disabled */
|
|
#endif
|
|
}
|
|
|
|
LZ4_stream_t* LZ4_initStream (void* buffer, size_t size)
|
|
{
|
|
DEBUGLOG(5, "LZ4_initStream");
|
|
if (buffer == NULL) { return NULL; }
|
|
if (size < sizeof(LZ4_stream_t)) { return NULL; }
|
|
if (!LZ4_isAligned(buffer, LZ4_stream_t_alignment())) return NULL;
|
|
MEM_INIT(buffer, 0, sizeof(LZ4_stream_t_internal));
|
|
return (LZ4_stream_t*)buffer;
|
|
}
|
|
|
|
/* resetStream is now deprecated,
|
|
* prefer initStream() which is more general */
|
|
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_internal));
|
|
}
|
|
|
|
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);
|
|
|
|
/* It's necessary to reset the context,
|
|
* and not just continue it with prepareTable()
|
|
* to avoid any risk of generating overflowing matchIndex
|
|
* when compressing using this dictionary */
|
|
LZ4_resetStream(LZ4_dict);
|
|
|
|
/* We always increment the offset by 64 KB, since, if the dict is longer,
|
|
* we truncate it to the last 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. */
|
|
dict->currentOffset += 64 KB;
|
|
|
|
if (dictSize < (int)HASH_UNIT) {
|
|
return 0;
|
|
}
|
|
|
|
if ((dictEnd - p) > 64 KB) p = dictEnd - 64 KB;
|
|
base = dictEnd - dict->currentOffset;
|
|
dict->dictionary = p;
|
|
dict->dictSize = (U32)(dictEnd - p);
|
|
dict->tableType = (U32)tableType;
|
|
|
|
while (p <= dictEnd-HASH_UNIT) {
|
|
LZ4_putPosition(p, dict->hashTable, tableType, base);
|
|
p+=3;
|
|
}
|
|
|
|
return (int)dict->dictSize;
|
|
}
|
|
|
|
void LZ4_attach_dictionary(LZ4_stream_t* workingStream, const LZ4_stream_t* dictionaryStream) {
|
|
const LZ4_stream_t_internal* dictCtx = dictionaryStream == NULL ? NULL :
|
|
&(dictionaryStream->internal_donotuse);
|
|
|
|
DEBUGLOG(4, "LZ4_attach_dictionary (%p, %p, size %u)",
|
|
workingStream, dictionaryStream,
|
|
dictCtx != NULL ? dictCtx->dictSize : 0);
|
|
|
|
if (dictCtx != 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 (workingStream->internal_donotuse.currentOffset == 0) {
|
|
workingStream->internal_donotuse.currentOffset = 64 KB;
|
|
}
|
|
|
|
/* Don't actually attach an empty dictionary.
|
|
*/
|
|
if (dictCtx->dictSize == 0) {
|
|
dictCtx = NULL;
|
|
}
|
|
}
|
|
workingStream->internal_donotuse.dictCtx = dictCtx;
|
|
}
|
|
|
|
|
|
static void LZ4_renormDictT(LZ4_stream_t_internal* LZ4_dict, int nextSize)
|
|
{
|
|
assert(nextSize >= 0);
|
|
if (LZ4_dict->currentOffset + (unsigned)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* dictEnd = streamPtr->dictionary + streamPtr->dictSize;
|
|
|
|
DEBUGLOG(5, "LZ4_compress_fast_continue (inputSize=%i)", inputSize);
|
|
|
|
LZ4_renormDictT(streamPtr, inputSize); /* avoid index overflow */
|
|
if (acceleration < 1) acceleration = LZ4_ACCELERATION_DEFAULT;
|
|
if (acceleration > LZ4_ACCELERATION_MAX) acceleration = LZ4_ACCELERATION_MAX;
|
|
|
|
/* invalidate tiny dictionaries */
|
|
if ( (streamPtr->dictSize-1 < 4-1) /* intentional underflow */
|
|
&& (dictEnd != (const BYTE*)source) ) {
|
|
DEBUGLOG(5, "LZ4_compress_fast_continue: dictSize(%u) at addr:%p is too small", streamPtr->dictSize, streamPtr->dictionary);
|
|
streamPtr->dictSize = 0;
|
|
streamPtr->dictionary = (const BYTE*)source;
|
|
dictEnd = (const BYTE*)source;
|
|
}
|
|
|
|
/* 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, NULL, maxOutputSize, limitedOutput, tableType, withPrefix64k, dictSmall, acceleration);
|
|
else
|
|
return LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, 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.
|
|
*/
|
|
LZ4_memcpy(streamPtr, streamPtr->dictCtx, sizeof(*streamPtr));
|
|
result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingExtDict, noDictIssue, acceleration);
|
|
} else {
|
|
result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingDictCtx, noDictIssue, acceleration);
|
|
}
|
|
} else {
|
|
if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset)) {
|
|
result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingExtDict, dictSmall, acceleration);
|
|
} else {
|
|
result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingExtDict, noDictIssue, acceleration);
|
|
}
|
|
}
|
|
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, NULL, 0, notLimited, byU32, usingExtDict, dictSmall, 1);
|
|
} else {
|
|
result = LZ4_compress_generic(streamPtr, source, dest, srcSize, NULL, 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 = (int)dict->dictSize; }
|
|
|
|
if (safeBuffer == NULL) assert(dictSize == 0);
|
|
if (dictSize > 0)
|
|
memmove(safeBuffer, previousDictEnd - dictSize, dictSize);
|
|
|
|
dict->dictionary = (const BYTE*)safeBuffer;
|
|
dict->dictSize = (U32)dictSize;
|
|
|
|
return dictSize;
|
|
}
|
|
|
|
|
|
|
|
/*-*******************************
|
|
* Decompression functions
|
|
********************************/
|
|
|
|
typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
|
|
typedef enum { decode_full_block = 0, partial_decode = 1 } earlyEnd_directive;
|
|
|
|
#undef MIN
|
|
#define MIN(a,b) ( (a) < (b) ? (a) : (b) )
|
|
|
|
/* Read the variable-length literal or match length.
|
|
*
|
|
* ip - pointer to use as input.
|
|
* lencheck - end ip. Return an error if ip advances >= lencheck.
|
|
* loop_check - check ip >= lencheck in body of loop. Returns loop_error if so.
|
|
* initial_check - check ip >= lencheck before start of loop. Returns initial_error if so.
|
|
* error (output) - error code. Should be set to 0 before call.
|
|
*/
|
|
typedef enum { loop_error = -2, initial_error = -1, ok = 0 } variable_length_error;
|
|
LZ4_FORCE_INLINE unsigned
|
|
read_variable_length(const BYTE**ip, const BYTE* lencheck,
|
|
int loop_check, int initial_check,
|
|
variable_length_error* error)
|
|
{
|
|
U32 length = 0;
|
|
U32 s;
|
|
if (initial_check && unlikely((*ip) >= lencheck)) { /* overflow detection */
|
|
*error = initial_error;
|
|
return length;
|
|
}
|
|
do {
|
|
s = **ip;
|
|
(*ip)++;
|
|
length += s;
|
|
if (loop_check && unlikely((*ip) >= lencheck)) { /* overflow detection */
|
|
*error = loop_error;
|
|
return length;
|
|
}
|
|
} while (s==255);
|
|
|
|
return length;
|
|
}
|
|
|
|
/*! 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_INLINE int
|
|
LZ4_decompress_generic(
|
|
const char* const src,
|
|
char* const dst,
|
|
int srcSize,
|
|
int outputSize, /* If endOnInput==endOnInputSize, this value is `dstCapacity` */
|
|
|
|
endCondition_directive endOnInput, /* endOnOutputSize, endOnInputSize */
|
|
earlyEnd_directive partialDecoding, /* full, partial */
|
|
dict_directive 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 */
|
|
)
|
|
{
|
|
if (src == NULL) { return -1; }
|
|
|
|
{ const BYTE* ip = (const BYTE*) src;
|
|
const BYTE* const iend = ip + srcSize;
|
|
|
|
BYTE* op = (BYTE*) dst;
|
|
BYTE* const oend = op + outputSize;
|
|
BYTE* cpy;
|
|
|
|
const BYTE* const dictEnd = (dictStart == NULL) ? NULL : dictStart + dictSize;
|
|
|
|
const int safeDecode = (endOnInput==endOnInputSize);
|
|
const int checkOffset = ((safeDecode) && (dictSize < (int)(64 KB)));
|
|
|
|
|
|
/* Set up the "end" pointers for the shortcut. */
|
|
const BYTE* const shortiend = iend - (endOnInput ? 14 : 8) /*maxLL*/ - 2 /*offset*/;
|
|
const BYTE* const shortoend = oend - (endOnInput ? 14 : 8) /*maxLL*/ - 18 /*maxML*/;
|
|
|
|
const BYTE* match;
|
|
size_t offset;
|
|
unsigned token;
|
|
size_t length;
|
|
|
|
|
|
DEBUGLOG(5, "LZ4_decompress_generic (srcSize:%i, dstSize:%i)", srcSize, outputSize);
|
|
|
|
/* Special cases */
|
|
assert(lowPrefix <= op);
|
|
if ((endOnInput) && (unlikely(outputSize==0))) {
|
|
/* Empty output buffer */
|
|
if (partialDecoding) return 0;
|
|
return ((srcSize==1) && (*ip==0)) ? 0 : -1;
|
|
}
|
|
if ((!endOnInput) && (unlikely(outputSize==0))) { return (*ip==0 ? 1 : -1); }
|
|
if ((endOnInput) && unlikely(srcSize==0)) { return -1; }
|
|
|
|
/* Currently the fast loop shows a regression on qualcomm arm chips. */
|
|
#if LZ4_FAST_DEC_LOOP
|
|
if ((oend - op) < FASTLOOP_SAFE_DISTANCE) {
|
|
DEBUGLOG(6, "skip fast decode loop");
|
|
goto safe_decode;
|
|
}
|
|
|
|
/* Fast loop : decode sequences as long as output < iend-FASTLOOP_SAFE_DISTANCE */
|
|
while (1) {
|
|
/* Main fastloop assertion: We can always wildcopy FASTLOOP_SAFE_DISTANCE */
|
|
assert(oend - op >= FASTLOOP_SAFE_DISTANCE);
|
|
if (endOnInput) { assert(ip < iend); }
|
|
token = *ip++;
|
|
length = token >> ML_BITS; /* literal length */
|
|
|
|
assert(!endOnInput || ip <= iend); /* ip < iend before the increment */
|
|
|
|
/* decode literal length */
|
|
if (length == RUN_MASK) {
|
|
variable_length_error error = ok;
|
|
length += read_variable_length(&ip, iend-RUN_MASK, (int)endOnInput, (int)endOnInput, &error);
|
|
if (error == initial_error) { goto _output_error; }
|
|
if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)(op))) { goto _output_error; } /* overflow detection */
|
|
if ((safeDecode) && unlikely((uptrval)(ip)+length<(uptrval)(ip))) { goto _output_error; } /* overflow detection */
|
|
|
|
/* copy literals */
|
|
cpy = op+length;
|
|
LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH);
|
|
if (endOnInput) { /* LZ4_decompress_safe() */
|
|
if ((cpy>oend-32) || (ip+length>iend-32)) { goto safe_literal_copy; }
|
|
LZ4_wildCopy32(op, ip, cpy);
|
|
} else { /* LZ4_decompress_fast() */
|
|
if (cpy>oend-8) { goto safe_literal_copy; }
|
|
LZ4_wildCopy8(op, ip, cpy); /* LZ4_decompress_fast() cannot copy more than 8 bytes at a time :
|
|
* it doesn't know input length, and only relies on end-of-block properties */
|
|
}
|
|
ip += length; op = cpy;
|
|
} else {
|
|
cpy = op+length;
|
|
if (endOnInput) { /* LZ4_decompress_safe() */
|
|
DEBUGLOG(7, "copy %u bytes in a 16-bytes stripe", (unsigned)length);
|
|
/* We don't need to check oend, since we check it once for each loop below */
|
|
if (ip > iend-(16 + 1/*max lit + offset + nextToken*/)) { goto safe_literal_copy; }
|
|
/* Literals can only be 14, but hope compilers optimize if we copy by a register size */
|
|
LZ4_memcpy(op, ip, 16);
|
|
} else { /* LZ4_decompress_fast() */
|
|
/* LZ4_decompress_fast() cannot copy more than 8 bytes at a time :
|
|
* it doesn't know input length, and relies on end-of-block properties */
|
|
LZ4_memcpy(op, ip, 8);
|
|
if (length > 8) { LZ4_memcpy(op+8, ip+8, 8); }
|
|
}
|
|
ip += length; op = cpy;
|
|
}
|
|
|
|
/* get offset */
|
|
offset = LZ4_readLE16(ip); ip+=2;
|
|
match = op - offset;
|
|
assert(match <= op);
|
|
|
|
/* get matchlength */
|
|
length = token & ML_MASK;
|
|
|
|
if (length == ML_MASK) {
|
|
variable_length_error error = ok;
|
|
if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) { goto _output_error; } /* Error : offset outside buffers */
|
|
length += read_variable_length(&ip, iend - LASTLITERALS + 1, (int)endOnInput, 0, &error);
|
|
if (error != ok) { goto _output_error; }
|
|
if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)op)) { goto _output_error; } /* overflow detection */
|
|
length += MINMATCH;
|
|
if (op + length >= oend - FASTLOOP_SAFE_DISTANCE) {
|
|
goto safe_match_copy;
|
|
}
|
|
} else {
|
|
length += MINMATCH;
|
|
if (op + length >= oend - FASTLOOP_SAFE_DISTANCE) {
|
|
goto safe_match_copy;
|
|
}
|
|
|
|
/* Fastpath check: Avoids a branch in LZ4_wildCopy32 if true */
|
|
if ((dict == withPrefix64k) || (match >= lowPrefix)) {
|
|
if (offset >= 8) {
|
|
assert(match >= lowPrefix);
|
|
assert(match <= op);
|
|
assert(op + 18 <= oend);
|
|
|
|
LZ4_memcpy(op, match, 8);
|
|
LZ4_memcpy(op+8, match+8, 8);
|
|
LZ4_memcpy(op+16, match+16, 2);
|
|
op += length;
|
|
continue;
|
|
} } }
|
|
|
|
if (checkOffset && (unlikely(match + dictSize < lowPrefix))) { goto _output_error; } /* Error : offset outside buffers */
|
|
/* match starting within external dictionary */
|
|
if ((dict==usingExtDict) && (match < lowPrefix)) {
|
|
if (unlikely(op+length > oend-LASTLITERALS)) {
|
|
if (partialDecoding) {
|
|
DEBUGLOG(7, "partialDecoding: dictionary match, close to dstEnd");
|
|
length = MIN(length, (size_t)(oend-op));
|
|
} else {
|
|
goto _output_error; /* end-of-block condition violated */
|
|
} }
|
|
|
|
if (length <= (size_t)(lowPrefix-match)) {
|
|
/* match fits entirely within external dictionary : just copy */
|
|
memmove(op, dictEnd - (lowPrefix-match), length);
|
|
op += length;
|
|
} else {
|
|
/* match stretches into both external dictionary and current block */
|
|
size_t const copySize = (size_t)(lowPrefix - match);
|
|
size_t const restSize = length - copySize;
|
|
LZ4_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 {
|
|
LZ4_memcpy(op, lowPrefix, restSize);
|
|
op += restSize;
|
|
} }
|
|
continue;
|
|
}
|
|
|
|
/* copy match within block */
|
|
cpy = op + length;
|
|
|
|
assert((op <= oend) && (oend-op >= 32));
|
|
if (unlikely(offset<16)) {
|
|
LZ4_memcpy_using_offset(op, match, cpy, offset);
|
|
} else {
|
|
LZ4_wildCopy32(op, match, cpy);
|
|
}
|
|
|
|
op = cpy; /* wildcopy correction */
|
|
}
|
|
safe_decode:
|
|
#endif
|
|
|
|
/* Main Loop : decode remaining sequences where output < FASTLOOP_SAFE_DISTANCE */
|
|
while (1) {
|
|
token = *ip++;
|
|
length = token >> ML_BITS; /* literal length */
|
|
|
|
assert(!endOnInput || ip <= iend); /* ip < iend before the increment */
|
|
|
|
/* A two-stage shortcut for the most common case:
|
|
* 1) If the literal length is 0..14, and there is enough space,
|
|
* enter the shortcut and copy 16 bytes on behalf of the literals
|
|
* (in the fast mode, only 8 bytes can be safely copied this way).
|
|
* 2) Further if the match length is 4..18, copy 18 bytes in a similar
|
|
* manner; but we ensure that there's enough space in the output for
|
|
* those 18 bytes earlier, upon entering the shortcut (in other words,
|
|
* there is a combined check for both stages).
|
|
*/
|
|
if ( (endOnInput ? length != RUN_MASK : length <= 8)
|
|
/* strictly "less than" on input, to re-enter the loop with at least one byte */
|
|
&& likely((endOnInput ? ip < shortiend : 1) & (op <= shortoend)) ) {
|
|
/* Copy the literals */
|
|
LZ4_memcpy(op, ip, endOnInput ? 16 : 8);
|
|
op += length; ip += length;
|
|
|
|
/* The second stage: prepare for match copying, decode full info.
|
|
* If it doesn't work out, the info won't be wasted. */
|
|
length = token & ML_MASK; /* match length */
|
|
offset = LZ4_readLE16(ip); ip += 2;
|
|
match = op - offset;
|
|
assert(match <= op); /* check overflow */
|
|
|
|
/* Do not deal with overlapping matches. */
|
|
if ( (length != ML_MASK)
|
|
&& (offset >= 8)
|
|
&& (dict==withPrefix64k || match >= lowPrefix) ) {
|
|
/* Copy the match. */
|
|
LZ4_memcpy(op + 0, match + 0, 8);
|
|
LZ4_memcpy(op + 8, match + 8, 8);
|
|
LZ4_memcpy(op +16, match +16, 2);
|
|
op += length + MINMATCH;
|
|
/* Both stages worked, load the next token. */
|
|
continue;
|
|
}
|
|
|
|
/* The second stage didn't work out, but the info is ready.
|
|
* Propel it right to the point of match copying. */
|
|
goto _copy_match;
|
|
}
|
|
|
|
/* decode literal length */
|
|
if (length == RUN_MASK) {
|
|
variable_length_error error = ok;
|
|
length += read_variable_length(&ip, iend-RUN_MASK, (int)endOnInput, (int)endOnInput, &error);
|
|
if (error == initial_error) { goto _output_error; }
|
|
if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)(op))) { goto _output_error; } /* overflow detection */
|
|
if ((safeDecode) && unlikely((uptrval)(ip)+length<(uptrval)(ip))) { goto _output_error; } /* overflow detection */
|
|
}
|
|
|
|
/* copy literals */
|
|
cpy = op+length;
|
|
#if LZ4_FAST_DEC_LOOP
|
|
safe_literal_copy:
|
|
#endif
|
|
LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH);
|
|
if ( ((endOnInput) && ((cpy>oend-MFLIMIT) || (ip+length>iend-(2+1+LASTLITERALS))) )
|
|
|| ((!endOnInput) && (cpy>oend-WILDCOPYLENGTH)) )
|
|
{
|
|
/* We've either hit the input parsing restriction or the output parsing restriction.
|
|
* In the normal scenario, decoding a full block, it must be the last sequence,
|
|
* otherwise it's an error (invalid input or dimensions).
|
|
* In partialDecoding scenario, it's necessary to ensure there is no buffer overflow.
|
|
*/
|
|
if (partialDecoding) {
|
|
/* Since we are partial decoding we may be in this block because of the output parsing
|
|
* restriction, which is not valid since the output buffer is allowed to be undersized.
|
|
*/
|
|
assert(endOnInput);
|
|
DEBUGLOG(7, "partialDecoding: copying literals, close to input or output end")
|
|
DEBUGLOG(7, "partialDecoding: literal length = %u", (unsigned)length);
|
|
DEBUGLOG(7, "partialDecoding: remaining space in dstBuffer : %i", (int)(oend - op));
|
|
DEBUGLOG(7, "partialDecoding: remaining space in srcBuffer : %i", (int)(iend - ip));
|
|
/* Finishing in the middle of a literals segment,
|
|
* due to lack of input.
|
|
*/
|
|
if (ip+length > iend) {
|
|
length = (size_t)(iend-ip);
|
|
cpy = op + length;
|
|
}
|
|
/* Finishing in the middle of a literals segment,
|
|
* due to lack of output space.
|
|
*/
|
|
if (cpy > oend) {
|
|
cpy = oend;
|
|
assert(op<=oend);
|
|
length = (size_t)(oend-op);
|
|
}
|
|
} else {
|
|
/* We must be on the last sequence because of the parsing limitations so check
|
|
* that we exactly regenerate the original size (must be exact when !endOnInput).
|
|
*/
|
|
if ((!endOnInput) && (cpy != oend)) { goto _output_error; }
|
|
/* We must be on the last sequence (or invalid) because of the parsing limitations
|
|
* so check that we exactly consume the input and don't overrun the output buffer.
|
|
*/
|
|
if ((endOnInput) && ((ip+length != iend) || (cpy > oend))) {
|
|
DEBUGLOG(6, "should have been last run of literals")
|
|
DEBUGLOG(6, "ip(%p) + length(%i) = %p != iend (%p)", ip, (int)length, ip+length, iend);
|
|
DEBUGLOG(6, "or cpy(%p) > oend(%p)", cpy, oend);
|
|
goto _output_error;
|
|
}
|
|
}
|
|
memmove(op, ip, length); /* supports overlapping memory regions; only matters for in-place decompression scenarios */
|
|
ip += length;
|
|
op += length;
|
|
/* Necessarily EOF when !partialDecoding.
|
|
* When partialDecoding, it is EOF if we've either
|
|
* filled the output buffer or
|
|
* can't proceed with reading an offset for following match.
|
|
*/
|
|
if (!partialDecoding || (cpy == oend) || (ip >= (iend-2))) {
|
|
break;
|
|
}
|
|
} else {
|
|
LZ4_wildCopy8(op, ip, cpy); /* may overwrite up to WILDCOPYLENGTH beyond cpy */
|
|
ip += length; op = cpy;
|
|
}
|
|
|
|
/* get offset */
|
|
offset = LZ4_readLE16(ip); ip+=2;
|
|
match = op - offset;
|
|
|
|
/* get matchlength */
|
|
length = token & ML_MASK;
|
|
|
|
_copy_match:
|
|
if (length == ML_MASK) {
|
|
variable_length_error error = ok;
|
|
length += read_variable_length(&ip, iend - LASTLITERALS + 1, (int)endOnInput, 0, &error);
|
|
if (error != ok) goto _output_error;
|
|
if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)op)) goto _output_error; /* overflow detection */
|
|
}
|
|
length += MINMATCH;
|
|
|
|
#if LZ4_FAST_DEC_LOOP
|
|
safe_match_copy:
|
|
#endif
|
|
if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) goto _output_error; /* Error : offset outside buffers */
|
|
/* match starting within external dictionary */
|
|
if ((dict==usingExtDict) && (match < lowPrefix)) {
|
|
if (unlikely(op+length > oend-LASTLITERALS)) {
|
|
if (partialDecoding) length = MIN(length, (size_t)(oend-op));
|
|
else goto _output_error; /* doesn't respect parsing restriction */
|
|
}
|
|
|
|
if (length <= (size_t)(lowPrefix-match)) {
|
|
/* match fits entirely within external dictionary : just copy */
|
|
memmove(op, dictEnd - (lowPrefix-match), length);
|
|
op += length;
|
|
} else {
|
|
/* match stretches into both external dictionary and current block */
|
|
size_t const copySize = (size_t)(lowPrefix - match);
|
|
size_t const restSize = length - copySize;
|
|
LZ4_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 {
|
|
LZ4_memcpy(op, lowPrefix, restSize);
|
|
op += restSize;
|
|
} }
|
|
continue;
|
|
}
|
|
assert(match >= lowPrefix);
|
|
|
|
/* copy match within block */
|
|
cpy = op + length;
|
|
|
|
/* partialDecoding : may end anywhere within the block */
|
|
assert(op<=oend);
|
|
if (partialDecoding && (cpy > oend-MATCH_SAFEGUARD_DISTANCE)) {
|
|
size_t const mlen = MIN(length, (size_t)(oend-op));
|
|
const BYTE* const matchEnd = match + mlen;
|
|
BYTE* const copyEnd = op + mlen;
|
|
if (matchEnd > op) { /* overlap copy */
|
|
while (op < copyEnd) { *op++ = *match++; }
|
|
} else {
|
|
LZ4_memcpy(op, match, mlen);
|
|
}
|
|
op = copyEnd;
|
|
if (op == oend) { break; }
|
|
continue;
|
|
}
|
|
|
|
if (unlikely(offset<8)) {
|
|
LZ4_write32(op, 0); /* silence msan warning when offset==0 */
|
|
op[0] = match[0];
|
|
op[1] = match[1];
|
|
op[2] = match[2];
|
|
op[3] = match[3];
|
|
match += inc32table[offset];
|
|
LZ4_memcpy(op+4, match, 4);
|
|
match -= dec64table[offset];
|
|
} else {
|
|
LZ4_memcpy(op, match, 8);
|
|
match += 8;
|
|
}
|
|
op += 8;
|
|
|
|
if (unlikely(cpy > oend-MATCH_SAFEGUARD_DISTANCE)) {
|
|
BYTE* const oCopyLimit = oend - (WILDCOPYLENGTH-1);
|
|
if (cpy > oend-LASTLITERALS) { goto _output_error; } /* Error : last LASTLITERALS bytes must be literals (uncompressed) */
|
|
if (op < oCopyLimit) {
|
|
LZ4_wildCopy8(op, match, oCopyLimit);
|
|
match += oCopyLimit - op;
|
|
op = oCopyLimit;
|
|
}
|
|
while (op < cpy) { *op++ = *match++; }
|
|
} else {
|
|
LZ4_memcpy(op, match, 8);
|
|
if (length > 16) { LZ4_wildCopy8(op+8, match+8, cpy); }
|
|
}
|
|
op = cpy; /* wildcopy correction */
|
|
}
|
|
|
|
/* end of decoding */
|
|
if (endOnInput) {
|
|
DEBUGLOG(5, "decoded %i bytes", (int) (((char*)op)-dst));
|
|
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;
|
|
}
|
|
}
|
|
|
|
|
|
/*===== Instantiate the API decoding functions. =====*/
|
|
|
|
LZ4_FORCE_O2
|
|
int LZ4_decompress_safe(const char* source, char* dest, int compressedSize, int maxDecompressedSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxDecompressedSize,
|
|
endOnInputSize, decode_full_block, noDict,
|
|
(BYTE*)dest, NULL, 0);
|
|
}
|
|
|
|
LZ4_FORCE_O2
|
|
int LZ4_decompress_safe_partial(const char* src, char* dst, int compressedSize, int targetOutputSize, int dstCapacity)
|
|
{
|
|
dstCapacity = MIN(targetOutputSize, dstCapacity);
|
|
return LZ4_decompress_generic(src, dst, compressedSize, dstCapacity,
|
|
endOnInputSize, partial_decode,
|
|
noDict, (BYTE*)dst, NULL, 0);
|
|
}
|
|
|
|
LZ4_FORCE_O2
|
|
int LZ4_decompress_fast(const char* source, char* dest, int originalSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, 0, originalSize,
|
|
endOnOutputSize, decode_full_block, withPrefix64k,
|
|
(BYTE*)dest - 64 KB, NULL, 0);
|
|
}
|
|
|
|
/*===== Instantiate a few more decoding cases, used more than once. =====*/
|
|
|
|
LZ4_FORCE_O2 /* Exported, an obsolete API function. */
|
|
int LZ4_decompress_safe_withPrefix64k(const char* source, char* dest, int compressedSize, int maxOutputSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
|
|
endOnInputSize, decode_full_block, withPrefix64k,
|
|
(BYTE*)dest - 64 KB, NULL, 0);
|
|
}
|
|
|
|
/* Another obsolete API function, paired with the previous one. */
|
|
int LZ4_decompress_fast_withPrefix64k(const char* source, char* dest, int originalSize)
|
|
{
|
|
/* LZ4_decompress_fast doesn't validate match offsets,
|
|
* and thus serves well with any prefixed dictionary. */
|
|
return LZ4_decompress_fast(source, dest, originalSize);
|
|
}
|
|
|
|
LZ4_FORCE_O2
|
|
static int LZ4_decompress_safe_withSmallPrefix(const char* source, char* dest, int compressedSize, int maxOutputSize,
|
|
size_t prefixSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
|
|
endOnInputSize, decode_full_block, noDict,
|
|
(BYTE*)dest-prefixSize, NULL, 0);
|
|
}
|
|
|
|
LZ4_FORCE_O2
|
|
int LZ4_decompress_safe_forceExtDict(const char* source, char* dest,
|
|
int compressedSize, int maxOutputSize,
|
|
const void* dictStart, size_t dictSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
|
|
endOnInputSize, decode_full_block, usingExtDict,
|
|
(BYTE*)dest, (const BYTE*)dictStart, dictSize);
|
|
}
|
|
|
|
LZ4_FORCE_O2
|
|
static int LZ4_decompress_fast_extDict(const char* source, char* dest, int originalSize,
|
|
const void* dictStart, size_t dictSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, 0, originalSize,
|
|
endOnOutputSize, decode_full_block, usingExtDict,
|
|
(BYTE*)dest, (const BYTE*)dictStart, dictSize);
|
|
}
|
|
|
|
/* The "double dictionary" mode, for use with e.g. ring buffers: the first part
|
|
* of the dictionary is passed as prefix, and the second via dictStart + dictSize.
|
|
* These routines are used only once, in LZ4_decompress_*_continue().
|
|
*/
|
|
LZ4_FORCE_INLINE
|
|
int LZ4_decompress_safe_doubleDict(const char* source, char* dest, int compressedSize, int maxOutputSize,
|
|
size_t prefixSize, const void* dictStart, size_t dictSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
|
|
endOnInputSize, decode_full_block, usingExtDict,
|
|
(BYTE*)dest-prefixSize, (const BYTE*)dictStart, dictSize);
|
|
}
|
|
|
|
LZ4_FORCE_INLINE
|
|
int LZ4_decompress_fast_doubleDict(const char* source, char* dest, int originalSize,
|
|
size_t prefixSize, const void* dictStart, size_t dictSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, 0, originalSize,
|
|
endOnOutputSize, decode_full_block, usingExtDict,
|
|
(BYTE*)dest-prefixSize, (const BYTE*)dictStart, dictSize);
|
|
}
|
|
|
|
/*===== streaming decompression functions =====*/
|
|
|
|
LZ4_streamDecode_t* LZ4_createStreamDecode(void)
|
|
{
|
|
LZ4_streamDecode_t* lz4s = (LZ4_streamDecode_t*) ALLOC_AND_ZERO(sizeof(LZ4_streamDecode_t));
|
|
LZ4_STATIC_ASSERT(LZ4_STREAMDECODESIZE >= sizeof(LZ4_streamDecode_t_internal)); /* A compilation error here means LZ4_STREAMDECODESIZE is not large enough */
|
|
return lz4s;
|
|
}
|
|
|
|
int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream)
|
|
{
|
|
if (LZ4_stream == NULL) { 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;
|
|
}
|
|
|
|
/*! LZ4_decoderRingBufferSize() :
|
|
* when setting a ring buffer for streaming decompression (optional scenario),
|
|
* provides the minimum size of this ring buffer
|
|
* to be compatible with any source respecting maxBlockSize condition.
|
|
* Note : in a ring buffer scenario,
|
|
* blocks are presumed decompressed next to each other.
|
|
* When not enough space remains for next block (remainingSize < maxBlockSize),
|
|
* decoding resumes from beginning of ring buffer.
|
|
* @return : minimum ring buffer size,
|
|
* or 0 if there is an error (invalid maxBlockSize).
|
|
*/
|
|
int LZ4_decoderRingBufferSize(int maxBlockSize)
|
|
{
|
|
if (maxBlockSize < 0) return 0;
|
|
if (maxBlockSize > LZ4_MAX_INPUT_SIZE) return 0;
|
|
if (maxBlockSize < 16) maxBlockSize = 16;
|
|
return LZ4_DECODER_RING_BUFFER_SIZE(maxBlockSize);
|
|
}
|
|
|
|
/*
|
|
*_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
|
|
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->prefixSize == 0) {
|
|
/* The first call, no dictionary yet. */
|
|
assert(lz4sd->extDictSize == 0);
|
|
result = LZ4_decompress_safe(source, dest, compressedSize, maxOutputSize);
|
|
if (result <= 0) return result;
|
|
lz4sd->prefixSize = (size_t)result;
|
|
lz4sd->prefixEnd = (BYTE*)dest + result;
|
|
} else if (lz4sd->prefixEnd == (BYTE*)dest) {
|
|
/* They're rolling the current segment. */
|
|
if (lz4sd->prefixSize >= 64 KB - 1)
|
|
result = LZ4_decompress_safe_withPrefix64k(source, dest, compressedSize, maxOutputSize);
|
|
else if (lz4sd->extDictSize == 0)
|
|
result = LZ4_decompress_safe_withSmallPrefix(source, dest, compressedSize, maxOutputSize,
|
|
lz4sd->prefixSize);
|
|
else
|
|
result = LZ4_decompress_safe_doubleDict(source, dest, compressedSize, maxOutputSize,
|
|
lz4sd->prefixSize, lz4sd->externalDict, lz4sd->extDictSize);
|
|
if (result <= 0) return result;
|
|
lz4sd->prefixSize += (size_t)result;
|
|
lz4sd->prefixEnd += result;
|
|
} else {
|
|
/* The buffer wraps around, or they're switching to another buffer. */
|
|
lz4sd->extDictSize = lz4sd->prefixSize;
|
|
lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize;
|
|
result = LZ4_decompress_safe_forceExtDict(source, dest, compressedSize, maxOutputSize,
|
|
lz4sd->externalDict, lz4sd->extDictSize);
|
|
if (result <= 0) return result;
|
|
lz4sd->prefixSize = (size_t)result;
|
|
lz4sd->prefixEnd = (BYTE*)dest + result;
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
LZ4_FORCE_O2
|
|
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;
|
|
assert(originalSize >= 0);
|
|
|
|
if (lz4sd->prefixSize == 0) {
|
|
assert(lz4sd->extDictSize == 0);
|
|
result = LZ4_decompress_fast(source, dest, originalSize);
|
|
if (result <= 0) return result;
|
|
lz4sd->prefixSize = (size_t)originalSize;
|
|
lz4sd->prefixEnd = (BYTE*)dest + originalSize;
|
|
} else if (lz4sd->prefixEnd == (BYTE*)dest) {
|
|
if (lz4sd->prefixSize >= 64 KB - 1 || lz4sd->extDictSize == 0)
|
|
result = LZ4_decompress_fast(source, dest, originalSize);
|
|
else
|
|
result = LZ4_decompress_fast_doubleDict(source, dest, originalSize,
|
|
lz4sd->prefixSize, lz4sd->externalDict, lz4sd->extDictSize);
|
|
if (result <= 0) return result;
|
|
lz4sd->prefixSize += (size_t)originalSize;
|
|
lz4sd->prefixEnd += originalSize;
|
|
} else {
|
|
lz4sd->extDictSize = lz4sd->prefixSize;
|
|
lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize;
|
|
result = LZ4_decompress_fast_extDict(source, dest, originalSize,
|
|
lz4sd->externalDict, lz4sd->extDictSize);
|
|
if (result <= 0) return result;
|
|
lz4sd->prefixSize = (size_t)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
|
|
*/
|
|
|
|
int LZ4_decompress_safe_usingDict(const char* source, char* dest, int compressedSize, int maxOutputSize, const char* dictStart, int dictSize)
|
|
{
|
|
if (dictSize==0)
|
|
return LZ4_decompress_safe(source, dest, compressedSize, maxOutputSize);
|
|
if (dictStart+dictSize == dest) {
|
|
if (dictSize >= 64 KB - 1) {
|
|
return LZ4_decompress_safe_withPrefix64k(source, dest, compressedSize, maxOutputSize);
|
|
}
|
|
assert(dictSize >= 0);
|
|
return LZ4_decompress_safe_withSmallPrefix(source, dest, compressedSize, maxOutputSize, (size_t)dictSize);
|
|
}
|
|
assert(dictSize >= 0);
|
|
return LZ4_decompress_safe_forceExtDict(source, dest, compressedSize, maxOutputSize, dictStart, (size_t)dictSize);
|
|
}
|
|
|
|
int LZ4_decompress_fast_usingDict(const char* source, char* dest, int originalSize, const char* dictStart, int dictSize)
|
|
{
|
|
if (dictSize==0 || dictStart+dictSize == dest)
|
|
return LZ4_decompress_fast(source, dest, originalSize);
|
|
assert(dictSize >= 0);
|
|
return LZ4_decompress_fast_extDict(source, dest, originalSize, dictStart, (size_t)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* src, char* dest, int srcSize)
|
|
{
|
|
return LZ4_compress_default(src, dest, srcSize, LZ4_compressBound(srcSize));
|
|
}
|
|
int LZ4_compress_limitedOutput_withState (void* state, const char* src, char* dst, int srcSize, int dstSize)
|
|
{
|
|
return LZ4_compress_fast_extState(state, src, dst, srcSize, dstSize, 1);
|
|
}
|
|
int LZ4_compress_withState (void* state, const char* src, char* dst, int srcSize)
|
|
{
|
|
return LZ4_compress_fast_extState(state, src, dst, srcSize, LZ4_compressBound(srcSize), 1);
|
|
}
|
|
int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_stream, const char* src, char* dst, int srcSize, int dstCapacity)
|
|
{
|
|
return LZ4_compress_fast_continue(LZ4_stream, src, dst, srcSize, dstCapacity, 1);
|
|
}
|
|
int LZ4_compress_continue (LZ4_stream_t* LZ4_stream, const char* source, char* dest, int inputSize)
|
|
{
|
|
return LZ4_compress_fast_continue(LZ4_stream, source, dest, inputSize, LZ4_compressBound(inputSize), 1);
|
|
}
|
|
|
|
/*
|
|
These decompression functions 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(void) { 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;
|
|
}
|
|
|
|
#endif /* LZ4_COMMONDEFS_ONLY */
|
|
/*
|
|
LZ4 HC - High Compression Mode of LZ4
|
|
Copyright (C) 2011-2017, Yann Collet.
|
|
|
|
BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions are
|
|
met:
|
|
|
|
* Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
* Redistributions in binary form must reproduce the above
|
|
copyright notice, this list of conditions and the following disclaimer
|
|
in the documentation and/or other materials provided with the
|
|
distribution.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
You can contact the author at :
|
|
- LZ4 source repository : https://github.com/lz4/lz4
|
|
- LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
|
|
*/
|
|
/* note : lz4hc is not an independent module, it requires lz4.h/lz4.c for proper compilation */
|
|
|
|
|
|
/* *************************************
|
|
* Tuning Parameter
|
|
***************************************/
|
|
|
|
/*! HEAPMODE :
|
|
* Select how default compression function will allocate workplace memory,
|
|
* in stack (0:fastest), or in heap (1:requires malloc()).
|
|
* Since workplace is rather large, heap mode is recommended.
|
|
*/
|
|
#ifndef LZ4HC_HEAPMODE
|
|
# define LZ4HC_HEAPMODE 1
|
|
#endif
|
|
|
|
|
|
/*=== Dependency ===*/
|
|
#define LZ4_HC_STATIC_LINKING_ONLY
|
|
#include "lz4hc.h"
|
|
|
|
|
|
/*=== Common definitions ===*/
|
|
#if defined(__GNUC__)
|
|
# pragma GCC diagnostic ignored "-Wunused-function"
|
|
#endif
|
|
#if defined (__clang__)
|
|
# pragma clang diagnostic ignored "-Wunused-function"
|
|
#endif
|
|
|
|
#define LZ4_COMMONDEFS_ONLY
|
|
#ifndef LZ4_SRC_INCLUDED
|
|
#include "lz4.c" /* LZ4_count, constants, mem */
|
|
#endif
|
|
|
|
|
|
/*=== Enums ===*/
|
|
typedef enum { noDictCtx, usingDictCtxHc } dictCtx_directive;
|
|
|
|
|
|
/*=== Constants ===*/
|
|
#define OPTIMAL_ML (int)((ML_MASK-1)+MINMATCH)
|
|
#define LZ4_OPT_NUM (1<<12)
|
|
|
|
|
|
/*=== Macros ===*/
|
|
#define MIN(a,b) ( (a) < (b) ? (a) : (b) )
|
|
#define MAX(a,b) ( (a) > (b) ? (a) : (b) )
|
|
#define HASH_FUNCTION(i) (((i) * 2654435761U) >> ((MINMATCH*8)-LZ4HC_HASH_LOG))
|
|
#define DELTANEXTMAXD(p) chainTable[(p) & LZ4HC_MAXD_MASK] /* flexible, LZ4HC_MAXD dependent */
|
|
#define DELTANEXTU16(table, pos) table[(U16)(pos)] /* faster */
|
|
/* Make fields passed to, and updated by LZ4HC_encodeSequence explicit */
|
|
#define UPDATABLE(ip, op, anchor) &ip, &op, &anchor
|
|
|
|
static U32 LZ4HC_hashPtr(const void* ptr) { return HASH_FUNCTION(LZ4_read32(ptr)); }
|
|
|
|
|
|
/**************************************
|
|
* HC Compression
|
|
**************************************/
|
|
static void LZ4HC_clearTables (LZ4HC_CCtx_internal* hc4)
|
|
{
|
|
MEM_INIT(hc4->hashTable, 0, sizeof(hc4->hashTable));
|
|
MEM_INIT(hc4->chainTable, 0xFF, sizeof(hc4->chainTable));
|
|
}
|
|
|
|
static void LZ4HC_init_internal (LZ4HC_CCtx_internal* hc4, const BYTE* start)
|
|
{
|
|
uptrval startingOffset = (uptrval)(hc4->end - hc4->base);
|
|
if (startingOffset > 1 GB) {
|
|
LZ4HC_clearTables(hc4);
|
|
startingOffset = 0;
|
|
}
|
|
startingOffset += 64 KB;
|
|
hc4->nextToUpdate = (U32) startingOffset;
|
|
hc4->base = start - startingOffset;
|
|
hc4->end = start;
|
|
hc4->dictBase = start - startingOffset;
|
|
hc4->dictLimit = (U32) startingOffset;
|
|
hc4->lowLimit = (U32) startingOffset;
|
|
}
|
|
|
|
|
|
/* Update chains up to ip (excluded) */
|
|
LZ4_FORCE_INLINE void LZ4HC_Insert (LZ4HC_CCtx_internal* hc4, const BYTE* ip)
|
|
{
|
|
U16* const chainTable = hc4->chainTable;
|
|
U32* const hashTable = hc4->hashTable;
|
|
const BYTE* const base = hc4->base;
|
|
U32 const target = (U32)(ip - base);
|
|
U32 idx = hc4->nextToUpdate;
|
|
|
|
while (idx < target) {
|
|
U32 const h = LZ4HC_hashPtr(base+idx);
|
|
size_t delta = idx - hashTable[h];
|
|
if (delta>LZ4_DISTANCE_MAX) delta = LZ4_DISTANCE_MAX;
|
|
DELTANEXTU16(chainTable, idx) = (U16)delta;
|
|
hashTable[h] = idx;
|
|
idx++;
|
|
}
|
|
|
|
hc4->nextToUpdate = target;
|
|
}
|
|
|
|
/** LZ4HC_countBack() :
|
|
* @return : negative value, nb of common bytes before ip/match */
|
|
LZ4_FORCE_INLINE
|
|
int LZ4HC_countBack(const BYTE* const ip, const BYTE* const match,
|
|
const BYTE* const iMin, const BYTE* const mMin)
|
|
{
|
|
int back = 0;
|
|
int const min = (int)MAX(iMin - ip, mMin - match);
|
|
assert(min <= 0);
|
|
assert(ip >= iMin); assert((size_t)(ip-iMin) < (1U<<31));
|
|
assert(match >= mMin); assert((size_t)(match - mMin) < (1U<<31));
|
|
while ( (back > min)
|
|
&& (ip[back-1] == match[back-1]) )
|
|
back--;
|
|
return back;
|
|
}
|
|
|
|
#if defined(_MSC_VER)
|
|
# define LZ4HC_rotl32(x,r) _rotl(x,r)
|
|
#else
|
|
# define LZ4HC_rotl32(x,r) ((x << r) | (x >> (32 - r)))
|
|
#endif
|
|
|
|
|
|
static U32 LZ4HC_rotatePattern(size_t const rotate, U32 const pattern)
|
|
{
|
|
size_t const bitsToRotate = (rotate & (sizeof(pattern) - 1)) << 3;
|
|
if (bitsToRotate == 0) return pattern;
|
|
return LZ4HC_rotl32(pattern, (int)bitsToRotate);
|
|
}
|
|
|
|
/* LZ4HC_countPattern() :
|
|
* pattern32 must be a sample of repetitive pattern of length 1, 2 or 4 (but not 3!) */
|
|
static unsigned
|
|
LZ4HC_countPattern(const BYTE* ip, const BYTE* const iEnd, U32 const pattern32)
|
|
{
|
|
const BYTE* const iStart = ip;
|
|
reg_t const pattern = (sizeof(pattern)==8) ?
|
|
(reg_t)pattern32 + (((reg_t)pattern32) << (sizeof(pattern)*4)) : pattern32;
|
|
|
|
while (likely(ip < iEnd-(sizeof(pattern)-1))) {
|
|
reg_t const diff = LZ4_read_ARCH(ip) ^ pattern;
|
|
if (!diff) { ip+=sizeof(pattern); continue; }
|
|
ip += LZ4_NbCommonBytes(diff);
|
|
return (unsigned)(ip - iStart);
|
|
}
|
|
|
|
if (LZ4_isLittleEndian()) {
|
|
reg_t patternByte = pattern;
|
|
while ((ip<iEnd) && (*ip == (BYTE)patternByte)) {
|
|
ip++; patternByte >>= 8;
|
|
}
|
|
} else { /* big endian */
|
|
U32 bitOffset = (sizeof(pattern)*8) - 8;
|
|
while (ip < iEnd) {
|
|
BYTE const byte = (BYTE)(pattern >> bitOffset);
|
|
if (*ip != byte) break;
|
|
ip ++; bitOffset -= 8;
|
|
}
|
|
}
|
|
|
|
return (unsigned)(ip - iStart);
|
|
}
|
|
|
|
/* LZ4HC_reverseCountPattern() :
|
|
* pattern must be a sample of repetitive pattern of length 1, 2 or 4 (but not 3!)
|
|
* read using natural platform endianess */
|
|
static unsigned
|
|
LZ4HC_reverseCountPattern(const BYTE* ip, const BYTE* const iLow, U32 pattern)
|
|
{
|
|
const BYTE* const iStart = ip;
|
|
|
|
while (likely(ip >= iLow+4)) {
|
|
if (LZ4_read32(ip-4) != pattern) break;
|
|
ip -= 4;
|
|
}
|
|
{ const BYTE* bytePtr = (const BYTE*)(&pattern) + 3; /* works for any endianess */
|
|
while (likely(ip>iLow)) {
|
|
if (ip[-1] != *bytePtr) break;
|
|
ip--; bytePtr--;
|
|
} }
|
|
return (unsigned)(iStart - ip);
|
|
}
|
|
|
|
/* LZ4HC_protectDictEnd() :
|
|
* Checks if the match is in the last 3 bytes of the dictionary, so reading the
|
|
* 4 byte MINMATCH would overflow.
|
|
* @returns true if the match index is okay.
|
|
*/
|
|
static int LZ4HC_protectDictEnd(U32 const dictLimit, U32 const matchIndex)
|
|
{
|
|
return ((U32)((dictLimit - 1) - matchIndex) >= 3);
|
|
}
|
|
|
|
typedef enum { rep_untested, rep_not, rep_confirmed } repeat_state_e;
|
|
typedef enum { favorCompressionRatio=0, favorDecompressionSpeed } HCfavor_e;
|
|
|
|
LZ4_FORCE_INLINE int
|
|
LZ4HC_InsertAndGetWiderMatch (
|
|
LZ4HC_CCtx_internal* hc4,
|
|
const BYTE* const ip,
|
|
const BYTE* const iLowLimit,
|
|
const BYTE* const iHighLimit,
|
|
int longest,
|
|
const BYTE** matchpos,
|
|
const BYTE** startpos,
|
|
const int maxNbAttempts,
|
|
const int patternAnalysis,
|
|
const int chainSwap,
|
|
const dictCtx_directive dict,
|
|
const HCfavor_e favorDecSpeed)
|
|
{
|
|
U16* const chainTable = hc4->chainTable;
|
|
U32* const HashTable = hc4->hashTable;
|
|
const LZ4HC_CCtx_internal * const dictCtx = hc4->dictCtx;
|
|
const BYTE* const base = hc4->base;
|
|
const U32 dictLimit = hc4->dictLimit;
|
|
const BYTE* const lowPrefixPtr = base + dictLimit;
|
|
const U32 ipIndex = (U32)(ip - base);
|
|
const U32 lowestMatchIndex = (hc4->lowLimit + (LZ4_DISTANCE_MAX + 1) > ipIndex) ? hc4->lowLimit : ipIndex - LZ4_DISTANCE_MAX;
|
|
const BYTE* const dictBase = hc4->dictBase;
|
|
int const lookBackLength = (int)(ip-iLowLimit);
|
|
int nbAttempts = maxNbAttempts;
|
|
U32 matchChainPos = 0;
|
|
U32 const pattern = LZ4_read32(ip);
|
|
U32 matchIndex;
|
|
repeat_state_e repeat = rep_untested;
|
|
size_t srcPatternLength = 0;
|
|
|
|
DEBUGLOG(7, "LZ4HC_InsertAndGetWiderMatch");
|
|
/* First Match */
|
|
LZ4HC_Insert(hc4, ip);
|
|
matchIndex = HashTable[LZ4HC_hashPtr(ip)];
|
|
DEBUGLOG(7, "First match at index %u / %u (lowestMatchIndex)",
|
|
matchIndex, lowestMatchIndex);
|
|
|
|
while ((matchIndex>=lowestMatchIndex) && (nbAttempts>0)) {
|
|
int matchLength=0;
|
|
nbAttempts--;
|
|
assert(matchIndex < ipIndex);
|
|
if (favorDecSpeed && (ipIndex - matchIndex < 8)) {
|
|
/* do nothing */
|
|
} else if (matchIndex >= dictLimit) { /* within current Prefix */
|
|
const BYTE* const matchPtr = base + matchIndex;
|
|
assert(matchPtr >= lowPrefixPtr);
|
|
assert(matchPtr < ip);
|
|
assert(longest >= 1);
|
|
if (LZ4_read16(iLowLimit + longest - 1) == LZ4_read16(matchPtr - lookBackLength + longest - 1)) {
|
|
if (LZ4_read32(matchPtr) == pattern) {
|
|
int const back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, lowPrefixPtr) : 0;
|
|
matchLength = MINMATCH + (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit);
|
|
matchLength -= back;
|
|
if (matchLength > longest) {
|
|
longest = matchLength;
|
|
*matchpos = matchPtr + back;
|
|
*startpos = ip + back;
|
|
} } }
|
|
} else { /* lowestMatchIndex <= matchIndex < dictLimit */
|
|
const BYTE* const matchPtr = dictBase + matchIndex;
|
|
if (LZ4_read32(matchPtr) == pattern) {
|
|
const BYTE* const dictStart = dictBase + hc4->lowLimit;
|
|
int back = 0;
|
|
const BYTE* vLimit = ip + (dictLimit - matchIndex);
|
|
if (vLimit > iHighLimit) vLimit = iHighLimit;
|
|
matchLength = (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH;
|
|
if ((ip+matchLength == vLimit) && (vLimit < iHighLimit))
|
|
matchLength += LZ4_count(ip+matchLength, lowPrefixPtr, iHighLimit);
|
|
back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictStart) : 0;
|
|
matchLength -= back;
|
|
if (matchLength > longest) {
|
|
longest = matchLength;
|
|
*matchpos = base + matchIndex + back; /* virtual pos, relative to ip, to retrieve offset */
|
|
*startpos = ip + back;
|
|
} } }
|
|
|
|
if (chainSwap && matchLength==longest) { /* better match => select a better chain */
|
|
assert(lookBackLength==0); /* search forward only */
|
|
if (matchIndex + (U32)longest <= ipIndex) {
|
|
int const kTrigger = 4;
|
|
U32 distanceToNextMatch = 1;
|
|
int const end = longest - MINMATCH + 1;
|
|
int step = 1;
|
|
int accel = 1 << kTrigger;
|
|
int pos;
|
|
for (pos = 0; pos < end; pos += step) {
|
|
U32 const candidateDist = DELTANEXTU16(chainTable, matchIndex + (U32)pos);
|
|
step = (accel++ >> kTrigger);
|
|
if (candidateDist > distanceToNextMatch) {
|
|
distanceToNextMatch = candidateDist;
|
|
matchChainPos = (U32)pos;
|
|
accel = 1 << kTrigger;
|
|
}
|
|
}
|
|
if (distanceToNextMatch > 1) {
|
|
if (distanceToNextMatch > matchIndex) break; /* avoid overflow */
|
|
matchIndex -= distanceToNextMatch;
|
|
continue;
|
|
} } }
|
|
|
|
{ U32 const distNextMatch = DELTANEXTU16(chainTable, matchIndex);
|
|
if (patternAnalysis && distNextMatch==1 && matchChainPos==0) {
|
|
U32 const matchCandidateIdx = matchIndex-1;
|
|
/* may be a repeated pattern */
|
|
if (repeat == rep_untested) {
|
|
if ( ((pattern & 0xFFFF) == (pattern >> 16))
|
|
& ((pattern & 0xFF) == (pattern >> 24)) ) {
|
|
repeat = rep_confirmed;
|
|
srcPatternLength = LZ4HC_countPattern(ip+sizeof(pattern), iHighLimit, pattern) + sizeof(pattern);
|
|
} else {
|
|
repeat = rep_not;
|
|
} }
|
|
if ( (repeat == rep_confirmed) && (matchCandidateIdx >= lowestMatchIndex)
|
|
&& LZ4HC_protectDictEnd(dictLimit, matchCandidateIdx) ) {
|
|
const int extDict = matchCandidateIdx < dictLimit;
|
|
const BYTE* const matchPtr = (extDict ? dictBase : base) + matchCandidateIdx;
|
|
if (LZ4_read32(matchPtr) == pattern) { /* good candidate */
|
|
const BYTE* const dictStart = dictBase + hc4->lowLimit;
|
|
const BYTE* const iLimit = extDict ? dictBase + dictLimit : iHighLimit;
|
|
size_t forwardPatternLength = LZ4HC_countPattern(matchPtr+sizeof(pattern), iLimit, pattern) + sizeof(pattern);
|
|
if (extDict && matchPtr + forwardPatternLength == iLimit) {
|
|
U32 const rotatedPattern = LZ4HC_rotatePattern(forwardPatternLength, pattern);
|
|
forwardPatternLength += LZ4HC_countPattern(lowPrefixPtr, iHighLimit, rotatedPattern);
|
|
}
|
|
{ const BYTE* const lowestMatchPtr = extDict ? dictStart : lowPrefixPtr;
|
|
size_t backLength = LZ4HC_reverseCountPattern(matchPtr, lowestMatchPtr, pattern);
|
|
size_t currentSegmentLength;
|
|
if (!extDict && matchPtr - backLength == lowPrefixPtr && hc4->lowLimit < dictLimit) {
|
|
U32 const rotatedPattern = LZ4HC_rotatePattern((U32)(-(int)backLength), pattern);
|
|
backLength += LZ4HC_reverseCountPattern(dictBase + dictLimit, dictStart, rotatedPattern);
|
|
}
|
|
/* Limit backLength not go further than lowestMatchIndex */
|
|
backLength = matchCandidateIdx - MAX(matchCandidateIdx - (U32)backLength, lowestMatchIndex);
|
|
assert(matchCandidateIdx - backLength >= lowestMatchIndex);
|
|
currentSegmentLength = backLength + forwardPatternLength;
|
|
/* Adjust to end of pattern if the source pattern fits, otherwise the beginning of the pattern */
|
|
if ( (currentSegmentLength >= srcPatternLength) /* current pattern segment large enough to contain full srcPatternLength */
|
|
&& (forwardPatternLength <= srcPatternLength) ) { /* haven't reached this position yet */
|
|
U32 const newMatchIndex = matchCandidateIdx + (U32)forwardPatternLength - (U32)srcPatternLength; /* best position, full pattern, might be followed by more match */
|
|
if (LZ4HC_protectDictEnd(dictLimit, newMatchIndex))
|
|
matchIndex = newMatchIndex;
|
|
else {
|
|
/* Can only happen if started in the prefix */
|
|
assert(newMatchIndex >= dictLimit - 3 && newMatchIndex < dictLimit && !extDict);
|
|
matchIndex = dictLimit;
|
|
}
|
|
} else {
|
|
U32 const newMatchIndex = matchCandidateIdx - (U32)backLength; /* farthest position in current segment, will find a match of length currentSegmentLength + maybe some back */
|
|
if (!LZ4HC_protectDictEnd(dictLimit, newMatchIndex)) {
|
|
assert(newMatchIndex >= dictLimit - 3 && newMatchIndex < dictLimit && !extDict);
|
|
matchIndex = dictLimit;
|
|
} else {
|
|
matchIndex = newMatchIndex;
|
|
if (lookBackLength==0) { /* no back possible */
|
|
size_t const maxML = MIN(currentSegmentLength, srcPatternLength);
|
|
if ((size_t)longest < maxML) {
|
|
assert(base + matchIndex != ip);
|
|
if ((size_t)(ip - base) - matchIndex > LZ4_DISTANCE_MAX) break;
|
|
assert(maxML < 2 GB);
|
|
longest = (int)maxML;
|
|
*matchpos = base + matchIndex; /* virtual pos, relative to ip, to retrieve offset */
|
|
*startpos = ip;
|
|
}
|
|
{ U32 const distToNextPattern = DELTANEXTU16(chainTable, matchIndex);
|
|
if (distToNextPattern > matchIndex) break; /* avoid overflow */
|
|
matchIndex -= distToNextPattern;
|
|
} } } } }
|
|
continue;
|
|
} }
|
|
} } /* PA optimization */
|
|
|
|
/* follow current chain */
|
|
matchIndex -= DELTANEXTU16(chainTable, matchIndex + matchChainPos);
|
|
|
|
} /* while ((matchIndex>=lowestMatchIndex) && (nbAttempts)) */
|
|
|
|
if ( dict == usingDictCtxHc
|
|
&& nbAttempts > 0
|
|
&& ipIndex - lowestMatchIndex < LZ4_DISTANCE_MAX) {
|
|
size_t const dictEndOffset = (size_t)(dictCtx->end - dictCtx->base);
|
|
U32 dictMatchIndex = dictCtx->hashTable[LZ4HC_hashPtr(ip)];
|
|
assert(dictEndOffset <= 1 GB);
|
|
matchIndex = dictMatchIndex + lowestMatchIndex - (U32)dictEndOffset;
|
|
while (ipIndex - matchIndex <= LZ4_DISTANCE_MAX && nbAttempts--) {
|
|
const BYTE* const matchPtr = dictCtx->base + dictMatchIndex;
|
|
|
|
if (LZ4_read32(matchPtr) == pattern) {
|
|
int mlt;
|
|
int back = 0;
|
|
const BYTE* vLimit = ip + (dictEndOffset - dictMatchIndex);
|
|
if (vLimit > iHighLimit) vLimit = iHighLimit;
|
|
mlt = (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH;
|
|
back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictCtx->base + dictCtx->dictLimit) : 0;
|
|
mlt -= back;
|
|
if (mlt > longest) {
|
|
longest = mlt;
|
|
*matchpos = base + matchIndex + back;
|
|
*startpos = ip + back;
|
|
} }
|
|
|
|
{ U32 const nextOffset = DELTANEXTU16(dictCtx->chainTable, dictMatchIndex);
|
|
dictMatchIndex -= nextOffset;
|
|
matchIndex -= nextOffset;
|
|
} } }
|
|
|
|
return longest;
|
|
}
|
|
|
|
LZ4_FORCE_INLINE
|
|
int LZ4HC_InsertAndFindBestMatch(LZ4HC_CCtx_internal* const hc4, /* Index table will be updated */
|
|
const BYTE* const ip, const BYTE* const iLimit,
|
|
const BYTE** matchpos,
|
|
const int maxNbAttempts,
|
|
const int patternAnalysis,
|
|
const dictCtx_directive dict)
|
|
{
|
|
const BYTE* uselessPtr = ip;
|
|
/* note : LZ4HC_InsertAndGetWiderMatch() is able to modify the starting position of a match (*startpos),
|
|
* but this won't be the case here, as we define iLowLimit==ip,
|
|
* so LZ4HC_InsertAndGetWiderMatch() won't be allowed to search past ip */
|
|
return LZ4HC_InsertAndGetWiderMatch(hc4, ip, ip, iLimit, MINMATCH-1, matchpos, &uselessPtr, maxNbAttempts, patternAnalysis, 0 /*chainSwap*/, dict, favorCompressionRatio);
|
|
}
|
|
|
|
/* LZ4HC_encodeSequence() :
|
|
* @return : 0 if ok,
|
|
* 1 if buffer issue detected */
|
|
LZ4_FORCE_INLINE int LZ4HC_encodeSequence (
|
|
const BYTE** _ip,
|
|
BYTE** _op,
|
|
const BYTE** _anchor,
|
|
int matchLength,
|
|
const BYTE* const match,
|
|
limitedOutput_directive limit,
|
|
BYTE* oend)
|
|
{
|
|
#define ip (*_ip)
|
|
#define op (*_op)
|
|
#define anchor (*_anchor)
|
|
|
|
size_t length;
|
|
BYTE* const token = op++;
|
|
|
|
#if defined(LZ4_DEBUG) && (LZ4_DEBUG >= 6)
|
|
static const BYTE* start = NULL;
|
|
static U32 totalCost = 0;
|
|
U32 const pos = (start==NULL) ? 0 : (U32)(anchor - start);
|
|
U32 const ll = (U32)(ip - anchor);
|
|
U32 const llAdd = (ll>=15) ? ((ll-15) / 255) + 1 : 0;
|
|
U32 const mlAdd = (matchLength>=19) ? ((matchLength-19) / 255) + 1 : 0;
|
|
U32 const cost = 1 + llAdd + ll + 2 + mlAdd;
|
|
if (start==NULL) start = anchor; /* only works for single segment */
|
|
/* g_debuglog_enable = (pos >= 2228) & (pos <= 2262); */
|
|
DEBUGLOG(6, "pos:%7u -- literals:%4u, match:%4i, offset:%5u, cost:%4u + %5u",
|
|
pos,
|
|
(U32)(ip - anchor), matchLength, (U32)(ip-match),
|
|
cost, totalCost);
|
|
totalCost += cost;
|
|
#endif
|
|
|
|
/* Encode Literal length */
|
|
length = (size_t)(ip - anchor);
|
|
LZ4_STATIC_ASSERT(notLimited == 0);
|
|
/* Check output limit */
|
|
if (limit && ((op + (length / 255) + length + (2 + 1 + LASTLITERALS)) > oend)) {
|
|
DEBUGLOG(6, "Not enough room to write %i literals (%i bytes remaining)",
|
|
(int)length, (int)(oend - op));
|
|
return 1;
|
|
}
|
|
if (length >= RUN_MASK) {
|
|
size_t len = length - RUN_MASK;
|
|
*token = (RUN_MASK << ML_BITS);
|
|
for(; len >= 255 ; len -= 255) *op++ = 255;
|
|
*op++ = (BYTE)len;
|
|
} else {
|
|
*token = (BYTE)(length << ML_BITS);
|
|
}
|
|
|
|
/* Copy Literals */
|
|
LZ4_wildCopy8(op, anchor, op + length);
|
|
op += length;
|
|
|
|
/* Encode Offset */
|
|
assert( (ip - match) <= LZ4_DISTANCE_MAX ); /* note : consider providing offset as a value, rather than as a pointer difference */
|
|
LZ4_writeLE16(op, (U16)(ip - match)); op += 2;
|
|
|
|
/* Encode MatchLength */
|
|
assert(matchLength >= MINMATCH);
|
|
length = (size_t)matchLength - MINMATCH;
|
|
if (limit && (op + (length / 255) + (1 + LASTLITERALS) > oend)) {
|
|
DEBUGLOG(6, "Not enough room to write match length");
|
|
return 1; /* Check output limit */
|
|
}
|
|
if (length >= ML_MASK) {
|
|
*token += ML_MASK;
|
|
length -= ML_MASK;
|
|
for(; length >= 510 ; length -= 510) { *op++ = 255; *op++ = 255; }
|
|
if (length >= 255) { length -= 255; *op++ = 255; }
|
|
*op++ = (BYTE)length;
|
|
} else {
|
|
*token += (BYTE)(length);
|
|
}
|
|
|
|
/* Prepare next loop */
|
|
ip += matchLength;
|
|
anchor = ip;
|
|
|
|
return 0;
|
|
}
|
|
#undef ip
|
|
#undef op
|
|
#undef anchor
|
|
|
|
LZ4_FORCE_INLINE int LZ4HC_compress_hashChain (
|
|
LZ4HC_CCtx_internal* const ctx,
|
|
const char* const source,
|
|
char* const dest,
|
|
int* srcSizePtr,
|
|
int const maxOutputSize,
|
|
int maxNbAttempts,
|
|
const limitedOutput_directive limit,
|
|
const dictCtx_directive dict
|
|
)
|
|
{
|
|
const int inputSize = *srcSizePtr;
|
|
const int patternAnalysis = (maxNbAttempts > 128); /* levels 9+ */
|
|
|
|
const BYTE* ip = (const BYTE*) source;
|
|
const BYTE* anchor = ip;
|
|
const BYTE* const iend = ip + inputSize;
|
|
const BYTE* const mflimit = iend - MFLIMIT;
|
|
const BYTE* const matchlimit = (iend - LASTLITERALS);
|
|
|
|
BYTE* optr = (BYTE*) dest;
|
|
BYTE* op = (BYTE*) dest;
|
|
BYTE* oend = op + maxOutputSize;
|
|
|
|
int ml0, ml, ml2, ml3;
|
|
const BYTE* start0;
|
|
const BYTE* ref0;
|
|
const BYTE* ref = NULL;
|
|
const BYTE* start2 = NULL;
|
|
const BYTE* ref2 = NULL;
|
|
const BYTE* start3 = NULL;
|
|
const BYTE* ref3 = NULL;
|
|
|
|
/* init */
|
|
*srcSizePtr = 0;
|
|
if (limit == fillOutput) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */
|
|
if (inputSize < LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */
|
|
|
|
/* Main Loop */
|
|
while (ip <= mflimit) {
|
|
ml = LZ4HC_InsertAndFindBestMatch(ctx, ip, matchlimit, &ref, maxNbAttempts, patternAnalysis, dict);
|
|
if (ml<MINMATCH) { ip++; continue; }
|
|
|
|
/* saved, in case we would skip too much */
|
|
start0 = ip; ref0 = ref; ml0 = ml;
|
|
|
|
_Search2:
|
|
if (ip+ml <= mflimit) {
|
|
ml2 = LZ4HC_InsertAndGetWiderMatch(ctx,
|
|
ip + ml - 2, ip + 0, matchlimit, ml, &ref2, &start2,
|
|
maxNbAttempts, patternAnalysis, 0, dict, favorCompressionRatio);
|
|
} else {
|
|
ml2 = ml;
|
|
}
|
|
|
|
if (ml2 == ml) { /* No better match => encode ML1 */
|
|
optr = op;
|
|
if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow;
|
|
continue;
|
|
}
|
|
|
|
if (start0 < ip) { /* first match was skipped at least once */
|
|
if (start2 < ip + ml0) { /* squeezing ML1 between ML0(original ML1) and ML2 */
|
|
ip = start0; ref = ref0; ml = ml0; /* restore initial ML1 */
|
|
} }
|
|
|
|
/* Here, start0==ip */
|
|
if ((start2 - ip) < 3) { /* First Match too small : removed */
|
|
ml = ml2;
|
|
ip = start2;
|
|
ref =ref2;
|
|
goto _Search2;
|
|
}
|
|
|
|
_Search3:
|
|
/* At this stage, we have :
|
|
* ml2 > ml1, and
|
|
* ip1+3 <= ip2 (usually < ip1+ml1) */
|
|
if ((start2 - ip) < OPTIMAL_ML) {
|
|
int correction;
|
|
int new_ml = ml;
|
|
if (new_ml > OPTIMAL_ML) new_ml = OPTIMAL_ML;
|
|
if (ip+new_ml > start2 + ml2 - MINMATCH) new_ml = (int)(start2 - ip) + ml2 - MINMATCH;
|
|
correction = new_ml - (int)(start2 - ip);
|
|
if (correction > 0) {
|
|
start2 += correction;
|
|
ref2 += correction;
|
|
ml2 -= correction;
|
|
}
|
|
}
|
|
/* Now, we have start2 = ip+new_ml, with new_ml = min(ml, OPTIMAL_ML=18) */
|
|
|
|
if (start2 + ml2 <= mflimit) {
|
|
ml3 = LZ4HC_InsertAndGetWiderMatch(ctx,
|
|
start2 + ml2 - 3, start2, matchlimit, ml2, &ref3, &start3,
|
|
maxNbAttempts, patternAnalysis, 0, dict, favorCompressionRatio);
|
|
} else {
|
|
ml3 = ml2;
|
|
}
|
|
|
|
if (ml3 == ml2) { /* No better match => encode ML1 and ML2 */
|
|
/* ip & ref are known; Now for ml */
|
|
if (start2 < ip+ml) ml = (int)(start2 - ip);
|
|
/* Now, encode 2 sequences */
|
|
optr = op;
|
|
if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow;
|
|
ip = start2;
|
|
optr = op;
|
|
if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml2, ref2, limit, oend)) {
|
|
ml = ml2;
|
|
ref = ref2;
|
|
goto _dest_overflow;
|
|
}
|
|
continue;
|
|
}
|
|
|
|
if (start3 < ip+ml+3) { /* Not enough space for match 2 : remove it */
|
|
if (start3 >= (ip+ml)) { /* can write Seq1 immediately ==> Seq2 is removed, so Seq3 becomes Seq1 */
|
|
if (start2 < ip+ml) {
|
|
int correction = (int)(ip+ml - start2);
|
|
start2 += correction;
|
|
ref2 += correction;
|
|
ml2 -= correction;
|
|
if (ml2 < MINMATCH) {
|
|
start2 = start3;
|
|
ref2 = ref3;
|
|
ml2 = ml3;
|
|
}
|
|
}
|
|
|
|
optr = op;
|
|
if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow;
|
|
ip = start3;
|
|
ref = ref3;
|
|
ml = ml3;
|
|
|
|
start0 = start2;
|
|
ref0 = ref2;
|
|
ml0 = ml2;
|
|
goto _Search2;
|
|
}
|
|
|
|
start2 = start3;
|
|
ref2 = ref3;
|
|
ml2 = ml3;
|
|
goto _Search3;
|
|
}
|
|
|
|
/*
|
|
* OK, now we have 3 ascending matches;
|
|
* let's write the first one ML1.
|
|
* ip & ref are known; Now decide ml.
|
|
*/
|
|
if (start2 < ip+ml) {
|
|
if ((start2 - ip) < OPTIMAL_ML) {
|
|
int correction;
|
|
if (ml > OPTIMAL_ML) ml = OPTIMAL_ML;
|
|
if (ip + ml > start2 + ml2 - MINMATCH) ml = (int)(start2 - ip) + ml2 - MINMATCH;
|
|
correction = ml - (int)(start2 - ip);
|
|
if (correction > 0) {
|
|
start2 += correction;
|
|
ref2 += correction;
|
|
ml2 -= correction;
|
|
}
|
|
} else {
|
|
ml = (int)(start2 - ip);
|
|
}
|
|
}
|
|
optr = op;
|
|
if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow;
|
|
|
|
/* ML2 becomes ML1 */
|
|
ip = start2; ref = ref2; ml = ml2;
|
|
|
|
/* ML3 becomes ML2 */
|
|
start2 = start3; ref2 = ref3; ml2 = ml3;
|
|
|
|
/* let's find a new ML3 */
|
|
goto _Search3;
|
|
}
|
|
|
|
_last_literals:
|
|
/* Encode Last Literals */
|
|
{ size_t lastRunSize = (size_t)(iend - anchor); /* literals */
|
|
size_t llAdd = (lastRunSize + 255 - RUN_MASK) / 255;
|
|
size_t const totalSize = 1 + llAdd + lastRunSize;
|
|
if (limit == fillOutput) oend += LASTLITERALS; /* restore correct value */
|
|
if (limit && (op + totalSize > oend)) {
|
|
if (limit == limitedOutput) return 0;
|
|
/* adapt lastRunSize to fill 'dest' */
|
|
lastRunSize = (size_t)(oend - op) - 1 /*token*/;
|
|
llAdd = (lastRunSize + 256 - RUN_MASK) / 256;
|
|
lastRunSize -= llAdd;
|
|
}
|
|
DEBUGLOG(6, "Final literal run : %i literals", (int)lastRunSize);
|
|
ip = anchor + lastRunSize; /* can be != iend if limit==fillOutput */
|
|
|
|
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) - source);
|
|
return (int) (((char*)op)-dest);
|
|
|
|
_dest_overflow:
|
|
if (limit == fillOutput) {
|
|
/* Assumption : ip, anchor, ml and ref must be set correctly */
|
|
size_t const ll = (size_t)(ip - anchor);
|
|
size_t const ll_addbytes = (ll + 240) / 255;
|
|
size_t const ll_totalCost = 1 + ll_addbytes + ll;
|
|
BYTE* const maxLitPos = oend - 3; /* 2 for offset, 1 for token */
|
|
DEBUGLOG(6, "Last sequence overflowing");
|
|
op = optr; /* restore correct out pointer */
|
|
if (op + ll_totalCost <= maxLitPos) {
|
|
/* ll validated; now adjust match length */
|
|
size_t const bytesLeftForMl = (size_t)(maxLitPos - (op+ll_totalCost));
|
|
size_t const maxMlSize = MINMATCH + (ML_MASK-1) + (bytesLeftForMl * 255);
|
|
assert(maxMlSize < INT_MAX); assert(ml >= 0);
|
|
if ((size_t)ml > maxMlSize) ml = (int)maxMlSize;
|
|
if ((oend + LASTLITERALS) - (op + ll_totalCost + 2) - 1 + ml >= MFLIMIT) {
|
|
LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, notLimited, oend);
|
|
} }
|
|
goto _last_literals;
|
|
}
|
|
/* compression failed */
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int LZ4HC_compress_optimal( LZ4HC_CCtx_internal* ctx,
|
|
const char* const source, char* dst,
|
|
int* srcSizePtr, int dstCapacity,
|
|
int const nbSearches, size_t sufficient_len,
|
|
const limitedOutput_directive limit, int const fullUpdate,
|
|
const dictCtx_directive dict,
|
|
const HCfavor_e favorDecSpeed);
|
|
|
|
|
|
LZ4_FORCE_INLINE int LZ4HC_compress_generic_internal (
|
|
LZ4HC_CCtx_internal* const ctx,
|
|
const char* const src,
|
|
char* const dst,
|
|
int* const srcSizePtr,
|
|
int const dstCapacity,
|
|
int cLevel,
|
|
const limitedOutput_directive limit,
|
|
const dictCtx_directive dict
|
|
)
|
|
{
|
|
typedef enum { lz4hc, lz4opt } lz4hc_strat_e;
|
|
typedef struct {
|
|
lz4hc_strat_e strat;
|
|
int nbSearches;
|
|
U32 targetLength;
|
|
} cParams_t;
|
|
static const cParams_t clTable[LZ4HC_CLEVEL_MAX+1] = {
|
|
{ lz4hc, 2, 16 }, /* 0, unused */
|
|
{ lz4hc, 2, 16 }, /* 1, unused */
|
|
{ lz4hc, 2, 16 }, /* 2, unused */
|
|
{ lz4hc, 4, 16 }, /* 3 */
|
|
{ lz4hc, 8, 16 }, /* 4 */
|
|
{ lz4hc, 16, 16 }, /* 5 */
|
|
{ lz4hc, 32, 16 }, /* 6 */
|
|
{ lz4hc, 64, 16 }, /* 7 */
|
|
{ lz4hc, 128, 16 }, /* 8 */
|
|
{ lz4hc, 256, 16 }, /* 9 */
|
|
{ lz4opt, 96, 64 }, /*10==LZ4HC_CLEVEL_OPT_MIN*/
|
|
{ lz4opt, 512,128 }, /*11 */
|
|
{ lz4opt,16384,LZ4_OPT_NUM }, /* 12==LZ4HC_CLEVEL_MAX */
|
|
};
|
|
|
|
DEBUGLOG(4, "LZ4HC_compress_generic(ctx=%p, src=%p, srcSize=%d, limit=%d)",
|
|
ctx, src, *srcSizePtr, limit);
|
|
|
|
if (limit == fillOutput && dstCapacity < 1) return 0; /* Impossible to store anything */
|
|
if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size (too large or negative) */
|
|
|
|
ctx->end += *srcSizePtr;
|
|
if (cLevel < 1) cLevel = LZ4HC_CLEVEL_DEFAULT; /* note : convention is different from lz4frame, maybe something to review */
|
|
cLevel = MIN(LZ4HC_CLEVEL_MAX, cLevel);
|
|
{ cParams_t const cParam = clTable[cLevel];
|
|
HCfavor_e const favor = ctx->favorDecSpeed ? favorDecompressionSpeed : favorCompressionRatio;
|
|
int result;
|
|
|
|
if (cParam.strat == lz4hc) {
|
|
result = LZ4HC_compress_hashChain(ctx,
|
|
src, dst, srcSizePtr, dstCapacity,
|
|
cParam.nbSearches, limit, dict);
|
|
} else {
|
|
assert(cParam.strat == lz4opt);
|
|
result = LZ4HC_compress_optimal(ctx,
|
|
src, dst, srcSizePtr, dstCapacity,
|
|
cParam.nbSearches, cParam.targetLength, limit,
|
|
cLevel == LZ4HC_CLEVEL_MAX, /* ultra mode */
|
|
dict, favor);
|
|
}
|
|
if (result <= 0) ctx->dirty = 1;
|
|
return result;
|
|
}
|
|
}
|
|
|
|
static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* ctxPtr, const BYTE* newBlock);
|
|
|
|
static int
|
|
LZ4HC_compress_generic_noDictCtx (
|
|
LZ4HC_CCtx_internal* const ctx,
|
|
const char* const src,
|
|
char* const dst,
|
|
int* const srcSizePtr,
|
|
int const dstCapacity,
|
|
int cLevel,
|
|
limitedOutput_directive limit
|
|
)
|
|
{
|
|
assert(ctx->dictCtx == NULL);
|
|
return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, noDictCtx);
|
|
}
|
|
|
|
static int
|
|
LZ4HC_compress_generic_dictCtx (
|
|
LZ4HC_CCtx_internal* const ctx,
|
|
const char* const src,
|
|
char* const dst,
|
|
int* const srcSizePtr,
|
|
int const dstCapacity,
|
|
int cLevel,
|
|
limitedOutput_directive limit
|
|
)
|
|
{
|
|
const size_t position = (size_t)(ctx->end - ctx->base) - ctx->lowLimit;
|
|
assert(ctx->dictCtx != NULL);
|
|
if (position >= 64 KB) {
|
|
ctx->dictCtx = NULL;
|
|
return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
|
|
} else if (position == 0 && *srcSizePtr > 4 KB) {
|
|
memcpy(ctx, ctx->dictCtx, sizeof(LZ4HC_CCtx_internal));
|
|
LZ4HC_setExternalDict(ctx, (const BYTE *)src);
|
|
ctx->compressionLevel = (short)cLevel;
|
|
return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
|
|
} else {
|
|
return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, usingDictCtxHc);
|
|
}
|
|
}
|
|
|
|
static int
|
|
LZ4HC_compress_generic (
|
|
LZ4HC_CCtx_internal* const ctx,
|
|
const char* const src,
|
|
char* const dst,
|
|
int* const srcSizePtr,
|
|
int const dstCapacity,
|
|
int cLevel,
|
|
limitedOutput_directive limit
|
|
)
|
|
{
|
|
if (ctx->dictCtx == NULL) {
|
|
return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
|
|
} else {
|
|
return LZ4HC_compress_generic_dictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
|
|
}
|
|
}
|
|
|
|
|
|
int LZ4_sizeofStateHC(void) { return (int)sizeof(LZ4_streamHC_t); }
|
|
|
|
static size_t LZ4_streamHC_t_alignment(void)
|
|
{
|
|
#if LZ4_ALIGN_TEST
|
|
typedef struct { char c; LZ4_streamHC_t t; } t_a;
|
|
return sizeof(t_a) - sizeof(LZ4_streamHC_t);
|
|
#else
|
|
return 1; /* effectively disabled */
|
|
#endif
|
|
}
|
|
|
|
/* state is presumed correctly initialized,
|
|
* in which case its size and alignment have already been validate */
|
|
int LZ4_compress_HC_extStateHC_fastReset (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
|
|
{
|
|
LZ4HC_CCtx_internal* const ctx = &((LZ4_streamHC_t*)state)->internal_donotuse;
|
|
if (!LZ4_isAligned(state, LZ4_streamHC_t_alignment())) return 0;
|
|
LZ4_resetStreamHC_fast((LZ4_streamHC_t*)state, compressionLevel);
|
|
LZ4HC_init_internal (ctx, (const BYTE*)src);
|
|
if (dstCapacity < LZ4_compressBound(srcSize))
|
|
return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, limitedOutput);
|
|
else
|
|
return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, notLimited);
|
|
}
|
|
|
|
int LZ4_compress_HC_extStateHC (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
|
|
{
|
|
LZ4_streamHC_t* const ctx = LZ4_initStreamHC(state, sizeof(*ctx));
|
|
if (ctx==NULL) return 0; /* init failure */
|
|
return LZ4_compress_HC_extStateHC_fastReset(state, src, dst, srcSize, dstCapacity, compressionLevel);
|
|
}
|
|
|
|
int LZ4_compress_HC(const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
|
|
{
|
|
#if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1
|
|
LZ4_streamHC_t* const statePtr = (LZ4_streamHC_t*)ALLOC(sizeof(LZ4_streamHC_t));
|
|
#else
|
|
LZ4_streamHC_t state;
|
|
LZ4_streamHC_t* const statePtr = &state;
|
|
#endif
|
|
int const cSize = LZ4_compress_HC_extStateHC(statePtr, src, dst, srcSize, dstCapacity, compressionLevel);
|
|
#if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1
|
|
FREEMEM(statePtr);
|
|
#endif
|
|
return cSize;
|
|
}
|
|
|
|
/* state is presumed sized correctly (>= sizeof(LZ4_streamHC_t)) */
|
|
int LZ4_compress_HC_destSize(void* state, const char* source, char* dest, int* sourceSizePtr, int targetDestSize, int cLevel)
|
|
{
|
|
LZ4_streamHC_t* const ctx = LZ4_initStreamHC(state, sizeof(*ctx));
|
|
if (ctx==NULL) return 0; /* init failure */
|
|
LZ4HC_init_internal(&ctx->internal_donotuse, (const BYTE*) source);
|
|
LZ4_setCompressionLevel(ctx, cLevel);
|
|
return LZ4HC_compress_generic(&ctx->internal_donotuse, source, dest, sourceSizePtr, targetDestSize, cLevel, fillOutput);
|
|
}
|
|
|
|
|
|
|
|
/**************************************
|
|
* Streaming Functions
|
|
**************************************/
|
|
/* allocation */
|
|
LZ4_streamHC_t* LZ4_createStreamHC(void)
|
|
{
|
|
LZ4_streamHC_t* const state =
|
|
(LZ4_streamHC_t*)ALLOC_AND_ZERO(sizeof(LZ4_streamHC_t));
|
|
if (state == NULL) return NULL;
|
|
LZ4_setCompressionLevel(state, LZ4HC_CLEVEL_DEFAULT);
|
|
return state;
|
|
}
|
|
|
|
int LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr)
|
|
{
|
|
DEBUGLOG(4, "LZ4_freeStreamHC(%p)", LZ4_streamHCPtr);
|
|
if (!LZ4_streamHCPtr) return 0; /* support free on NULL */
|
|
FREEMEM(LZ4_streamHCPtr);
|
|
return 0;
|
|
}
|
|
|
|
|
|
LZ4_streamHC_t* LZ4_initStreamHC (void* buffer, size_t size)
|
|
{
|
|
LZ4_streamHC_t* const LZ4_streamHCPtr = (LZ4_streamHC_t*)buffer;
|
|
/* if compilation fails here, LZ4_STREAMHCSIZE must be increased */
|
|
LZ4_STATIC_ASSERT(sizeof(LZ4HC_CCtx_internal) <= LZ4_STREAMHCSIZE);
|
|
DEBUGLOG(4, "LZ4_initStreamHC(%p, %u)", buffer, (unsigned)size);
|
|
/* check conditions */
|
|
if (buffer == NULL) return NULL;
|
|
if (size < sizeof(LZ4_streamHC_t)) return NULL;
|
|
if (!LZ4_isAligned(buffer, LZ4_streamHC_t_alignment())) return NULL;
|
|
/* init */
|
|
{ LZ4HC_CCtx_internal* const hcstate = &(LZ4_streamHCPtr->internal_donotuse);
|
|
MEM_INIT(hcstate, 0, sizeof(*hcstate)); }
|
|
LZ4_setCompressionLevel(LZ4_streamHCPtr, LZ4HC_CLEVEL_DEFAULT);
|
|
return LZ4_streamHCPtr;
|
|
}
|
|
|
|
/* just a stub */
|
|
void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
|
|
{
|
|
LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr));
|
|
LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel);
|
|
}
|
|
|
|
void LZ4_resetStreamHC_fast (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
|
|
{
|
|
DEBUGLOG(4, "LZ4_resetStreamHC_fast(%p, %d)", LZ4_streamHCPtr, compressionLevel);
|
|
if (LZ4_streamHCPtr->internal_donotuse.dirty) {
|
|
LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr));
|
|
} else {
|
|
/* preserve end - base : can trigger clearTable's threshold */
|
|
LZ4_streamHCPtr->internal_donotuse.end -= (uptrval)LZ4_streamHCPtr->internal_donotuse.base;
|
|
LZ4_streamHCPtr->internal_donotuse.base = NULL;
|
|
LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL;
|
|
}
|
|
LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel);
|
|
}
|
|
|
|
void LZ4_setCompressionLevel(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
|
|
{
|
|
DEBUGLOG(5, "LZ4_setCompressionLevel(%p, %d)", LZ4_streamHCPtr, compressionLevel);
|
|
if (compressionLevel < 1) compressionLevel = LZ4HC_CLEVEL_DEFAULT;
|
|
if (compressionLevel > LZ4HC_CLEVEL_MAX) compressionLevel = LZ4HC_CLEVEL_MAX;
|
|
LZ4_streamHCPtr->internal_donotuse.compressionLevel = (short)compressionLevel;
|
|
}
|
|
|
|
void LZ4_favorDecompressionSpeed(LZ4_streamHC_t* LZ4_streamHCPtr, int favor)
|
|
{
|
|
LZ4_streamHCPtr->internal_donotuse.favorDecSpeed = (favor!=0);
|
|
}
|
|
|
|
/* LZ4_loadDictHC() :
|
|
* LZ4_streamHCPtr is presumed properly initialized */
|
|
int LZ4_loadDictHC (LZ4_streamHC_t* LZ4_streamHCPtr,
|
|
const char* dictionary, int dictSize)
|
|
{
|
|
LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
|
|
DEBUGLOG(4, "LZ4_loadDictHC(ctx:%p, dict:%p, dictSize:%d)", LZ4_streamHCPtr, dictionary, dictSize);
|
|
assert(LZ4_streamHCPtr != NULL);
|
|
if (dictSize > 64 KB) {
|
|
dictionary += (size_t)dictSize - 64 KB;
|
|
dictSize = 64 KB;
|
|
}
|
|
/* need a full initialization, there are bad side-effects when using resetFast() */
|
|
{ int const cLevel = ctxPtr->compressionLevel;
|
|
LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr));
|
|
LZ4_setCompressionLevel(LZ4_streamHCPtr, cLevel);
|
|
}
|
|
LZ4HC_init_internal (ctxPtr, (const BYTE*)dictionary);
|
|
ctxPtr->end = (const BYTE*)dictionary + dictSize;
|
|
if (dictSize >= 4) LZ4HC_Insert (ctxPtr, ctxPtr->end-3);
|
|
return dictSize;
|
|
}
|
|
|
|
void LZ4_attach_HC_dictionary(LZ4_streamHC_t *working_stream, const LZ4_streamHC_t *dictionary_stream) {
|
|
working_stream->internal_donotuse.dictCtx = dictionary_stream != NULL ? &(dictionary_stream->internal_donotuse) : NULL;
|
|
}
|
|
|
|
/* compression */
|
|
|
|
static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* ctxPtr, const BYTE* newBlock)
|
|
{
|
|
DEBUGLOG(4, "LZ4HC_setExternalDict(%p, %p)", ctxPtr, newBlock);
|
|
if (ctxPtr->end >= ctxPtr->base + ctxPtr->dictLimit + 4)
|
|
LZ4HC_Insert (ctxPtr, ctxPtr->end-3); /* Referencing remaining dictionary content */
|
|
|
|
/* Only one memory segment for extDict, so any previous extDict is lost at this stage */
|
|
ctxPtr->lowLimit = ctxPtr->dictLimit;
|
|
ctxPtr->dictLimit = (U32)(ctxPtr->end - ctxPtr->base);
|
|
ctxPtr->dictBase = ctxPtr->base;
|
|
ctxPtr->base = newBlock - ctxPtr->dictLimit;
|
|
ctxPtr->end = newBlock;
|
|
ctxPtr->nextToUpdate = ctxPtr->dictLimit; /* match referencing will resume from there */
|
|
|
|
/* cannot reference an extDict and a dictCtx at the same time */
|
|
ctxPtr->dictCtx = NULL;
|
|
}
|
|
|
|
static int
|
|
LZ4_compressHC_continue_generic (LZ4_streamHC_t* LZ4_streamHCPtr,
|
|
const char* src, char* dst,
|
|
int* srcSizePtr, int dstCapacity,
|
|
limitedOutput_directive limit)
|
|
{
|
|
LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
|
|
DEBUGLOG(5, "LZ4_compressHC_continue_generic(ctx=%p, src=%p, srcSize=%d, limit=%d)",
|
|
LZ4_streamHCPtr, src, *srcSizePtr, limit);
|
|
assert(ctxPtr != NULL);
|
|
/* auto-init if forgotten */
|
|
if (ctxPtr->base == NULL) LZ4HC_init_internal (ctxPtr, (const BYTE*) src);
|
|
|
|
/* Check overflow */
|
|
if ((size_t)(ctxPtr->end - ctxPtr->base) > 2 GB) {
|
|
size_t dictSize = (size_t)(ctxPtr->end - ctxPtr->base) - ctxPtr->dictLimit;
|
|
if (dictSize > 64 KB) dictSize = 64 KB;
|
|
LZ4_loadDictHC(LZ4_streamHCPtr, (const char*)(ctxPtr->end) - dictSize, (int)dictSize);
|
|
}
|
|
|
|
/* Check if blocks follow each other */
|
|
if ((const BYTE*)src != ctxPtr->end)
|
|
LZ4HC_setExternalDict(ctxPtr, (const BYTE*)src);
|
|
|
|
/* Check overlapping input/dictionary space */
|
|
{ const BYTE* sourceEnd = (const BYTE*) src + *srcSizePtr;
|
|
const BYTE* const dictBegin = ctxPtr->dictBase + ctxPtr->lowLimit;
|
|
const BYTE* const dictEnd = ctxPtr->dictBase + ctxPtr->dictLimit;
|
|
if ((sourceEnd > dictBegin) && ((const BYTE*)src < dictEnd)) {
|
|
if (sourceEnd > dictEnd) sourceEnd = dictEnd;
|
|
ctxPtr->lowLimit = (U32)(sourceEnd - ctxPtr->dictBase);
|
|
if (ctxPtr->dictLimit - ctxPtr->lowLimit < 4) ctxPtr->lowLimit = ctxPtr->dictLimit;
|
|
} }
|
|
|
|
return LZ4HC_compress_generic (ctxPtr, src, dst, srcSizePtr, dstCapacity, ctxPtr->compressionLevel, limit);
|
|
}
|
|
|
|
int LZ4_compress_HC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* src, char* dst, int srcSize, int dstCapacity)
|
|
{
|
|
if (dstCapacity < LZ4_compressBound(srcSize))
|
|
return LZ4_compressHC_continue_generic (LZ4_streamHCPtr, src, dst, &srcSize, dstCapacity, limitedOutput);
|
|
else
|
|
return LZ4_compressHC_continue_generic (LZ4_streamHCPtr, src, dst, &srcSize, dstCapacity, notLimited);
|
|
}
|
|
|
|
int LZ4_compress_HC_continue_destSize (LZ4_streamHC_t* LZ4_streamHCPtr, const char* src, char* dst, int* srcSizePtr, int targetDestSize)
|
|
{
|
|
return LZ4_compressHC_continue_generic(LZ4_streamHCPtr, src, dst, srcSizePtr, targetDestSize, fillOutput);
|
|
}
|
|
|
|
|
|
|
|
/* LZ4_saveDictHC :
|
|
* save history content
|
|
* into a user-provided buffer
|
|
* which is then used to continue compression
|
|
*/
|
|
int LZ4_saveDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, char* safeBuffer, int dictSize)
|
|
{
|
|
LZ4HC_CCtx_internal* const streamPtr = &LZ4_streamHCPtr->internal_donotuse;
|
|
int const prefixSize = (int)(streamPtr->end - (streamPtr->base + streamPtr->dictLimit));
|
|
DEBUGLOG(5, "LZ4_saveDictHC(%p, %p, %d)", LZ4_streamHCPtr, safeBuffer, dictSize);
|
|
assert(prefixSize >= 0);
|
|
if (dictSize > 64 KB) dictSize = 64 KB;
|
|
if (dictSize < 4) dictSize = 0;
|
|
if (dictSize > prefixSize) dictSize = prefixSize;
|
|
if (safeBuffer == NULL) assert(dictSize == 0);
|
|
if (dictSize > 0)
|
|
memmove(safeBuffer, streamPtr->end - dictSize, dictSize);
|
|
{ U32 const endIndex = (U32)(streamPtr->end - streamPtr->base);
|
|
streamPtr->end = (const BYTE*)safeBuffer + dictSize;
|
|
streamPtr->base = streamPtr->end - endIndex;
|
|
streamPtr->dictLimit = endIndex - (U32)dictSize;
|
|
streamPtr->lowLimit = endIndex - (U32)dictSize;
|
|
if (streamPtr->nextToUpdate < streamPtr->dictLimit)
|
|
streamPtr->nextToUpdate = streamPtr->dictLimit;
|
|
}
|
|
return dictSize;
|
|
}
|
|
|
|
|
|
/***************************************************
|
|
* Deprecated Functions
|
|
***************************************************/
|
|
|
|
/* These functions currently generate deprecation warnings */
|
|
|
|
/* Wrappers for deprecated compression functions */
|
|
int LZ4_compressHC(const char* src, char* dst, int srcSize) { return LZ4_compress_HC (src, dst, srcSize, LZ4_compressBound(srcSize), 0); }
|
|
int LZ4_compressHC_limitedOutput(const char* src, char* dst, int srcSize, int maxDstSize) { return LZ4_compress_HC(src, dst, srcSize, maxDstSize, 0); }
|
|
int LZ4_compressHC2(const char* src, char* dst, int srcSize, int cLevel) { return LZ4_compress_HC (src, dst, srcSize, LZ4_compressBound(srcSize), cLevel); }
|
|
int LZ4_compressHC2_limitedOutput(const char* src, char* dst, int srcSize, int maxDstSize, int cLevel) { return LZ4_compress_HC(src, dst, srcSize, maxDstSize, cLevel); }
|
|
int LZ4_compressHC_withStateHC (void* state, const char* src, char* dst, int srcSize) { return LZ4_compress_HC_extStateHC (state, src, dst, srcSize, LZ4_compressBound(srcSize), 0); }
|
|
int LZ4_compressHC_limitedOutput_withStateHC (void* state, const char* src, char* dst, int srcSize, int maxDstSize) { return LZ4_compress_HC_extStateHC (state, src, dst, srcSize, maxDstSize, 0); }
|
|
int LZ4_compressHC2_withStateHC (void* state, const char* src, char* dst, int srcSize, int cLevel) { return LZ4_compress_HC_extStateHC(state, src, dst, srcSize, LZ4_compressBound(srcSize), cLevel); }
|
|
int LZ4_compressHC2_limitedOutput_withStateHC (void* state, const char* src, char* dst, int srcSize, int maxDstSize, int cLevel) { return LZ4_compress_HC_extStateHC(state, src, dst, srcSize, maxDstSize, cLevel); }
|
|
int LZ4_compressHC_continue (LZ4_streamHC_t* ctx, const char* src, char* dst, int srcSize) { return LZ4_compress_HC_continue (ctx, src, dst, srcSize, LZ4_compressBound(srcSize)); }
|
|
int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* ctx, const char* src, char* dst, int srcSize, int maxDstSize) { return LZ4_compress_HC_continue (ctx, src, dst, srcSize, maxDstSize); }
|
|
|
|
|
|
/* Deprecated streaming functions */
|
|
int LZ4_sizeofStreamStateHC(void) { return LZ4_STREAMHCSIZE; }
|
|
|
|
/* state is presumed correctly sized, aka >= sizeof(LZ4_streamHC_t)
|
|
* @return : 0 on success, !=0 if error */
|
|
int LZ4_resetStreamStateHC(void* state, char* inputBuffer)
|
|
{
|
|
LZ4_streamHC_t* const hc4 = LZ4_initStreamHC(state, sizeof(*hc4));
|
|
if (hc4 == NULL) return 1; /* init failed */
|
|
LZ4HC_init_internal (&hc4->internal_donotuse, (const BYTE*)inputBuffer);
|
|
return 0;
|
|
}
|
|
|
|
void* LZ4_createHC (const char* inputBuffer)
|
|
{
|
|
LZ4_streamHC_t* const hc4 = LZ4_createStreamHC();
|
|
if (hc4 == NULL) return NULL; /* not enough memory */
|
|
LZ4HC_init_internal (&hc4->internal_donotuse, (const BYTE*)inputBuffer);
|
|
return hc4;
|
|
}
|
|
|
|
int LZ4_freeHC (void* LZ4HC_Data)
|
|
{
|
|
if (!LZ4HC_Data) return 0; /* support free on NULL */
|
|
FREEMEM(LZ4HC_Data);
|
|
return 0;
|
|
}
|
|
|
|
int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* src, char* dst, int srcSize, int cLevel)
|
|
{
|
|
return LZ4HC_compress_generic (&((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse, src, dst, &srcSize, 0, cLevel, notLimited);
|
|
}
|
|
|
|
int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* src, char* dst, int srcSize, int dstCapacity, int cLevel)
|
|
{
|
|
return LZ4HC_compress_generic (&((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse, src, dst, &srcSize, dstCapacity, cLevel, limitedOutput);
|
|
}
|
|
|
|
char* LZ4_slideInputBufferHC(void* LZ4HC_Data)
|
|
{
|
|
LZ4_streamHC_t *ctx = (LZ4_streamHC_t*)LZ4HC_Data;
|
|
const BYTE *bufferStart = ctx->internal_donotuse.base + ctx->internal_donotuse.lowLimit;
|
|
LZ4_resetStreamHC_fast(ctx, ctx->internal_donotuse.compressionLevel);
|
|
/* avoid const char * -> char * conversion warning :( */
|
|
return (char *)(uptrval)bufferStart;
|
|
}
|
|
|
|
|
|
/* ================================================
|
|
* LZ4 Optimal parser (levels [LZ4HC_CLEVEL_OPT_MIN - LZ4HC_CLEVEL_MAX])
|
|
* ===============================================*/
|
|
typedef struct {
|
|
int price;
|
|
int off;
|
|
int mlen;
|
|
int litlen;
|
|
} LZ4HC_optimal_t;
|
|
|
|
/* price in bytes */
|
|
LZ4_FORCE_INLINE int LZ4HC_literalsPrice(int const litlen)
|
|
{
|
|
int price = litlen;
|
|
assert(litlen >= 0);
|
|
if (litlen >= (int)RUN_MASK)
|
|
price += 1 + ((litlen-(int)RUN_MASK) / 255);
|
|
return price;
|
|
}
|
|
|
|
|
|
/* requires mlen >= MINMATCH */
|
|
LZ4_FORCE_INLINE int LZ4HC_sequencePrice(int litlen, int mlen)
|
|
{
|
|
int price = 1 + 2 ; /* token + 16-bit offset */
|
|
assert(litlen >= 0);
|
|
assert(mlen >= MINMATCH);
|
|
|
|
price += LZ4HC_literalsPrice(litlen);
|
|
|
|
if (mlen >= (int)(ML_MASK+MINMATCH))
|
|
price += 1 + ((mlen-(int)(ML_MASK+MINMATCH)) / 255);
|
|
|
|
return price;
|
|
}
|
|
|
|
|
|
typedef struct {
|
|
int off;
|
|
int len;
|
|
} LZ4HC_match_t;
|
|
|
|
LZ4_FORCE_INLINE LZ4HC_match_t
|
|
LZ4HC_FindLongerMatch(LZ4HC_CCtx_internal* const ctx,
|
|
const BYTE* ip, const BYTE* const iHighLimit,
|
|
int minLen, int nbSearches,
|
|
const dictCtx_directive dict,
|
|
const HCfavor_e favorDecSpeed)
|
|
{
|
|
LZ4HC_match_t match = { 0 , 0 };
|
|
const BYTE* matchPtr = NULL;
|
|
/* note : LZ4HC_InsertAndGetWiderMatch() is able to modify the starting position of a match (*startpos),
|
|
* but this won't be the case here, as we define iLowLimit==ip,
|
|
* so LZ4HC_InsertAndGetWiderMatch() won't be allowed to search past ip */
|
|
int matchLength = LZ4HC_InsertAndGetWiderMatch(ctx, ip, ip, iHighLimit, minLen, &matchPtr, &ip, nbSearches, 1 /*patternAnalysis*/, 1 /*chainSwap*/, dict, favorDecSpeed);
|
|
if (matchLength <= minLen) return match;
|
|
if (favorDecSpeed) {
|
|
if ((matchLength>18) & (matchLength<=36)) matchLength=18; /* favor shortcut */
|
|
}
|
|
match.len = matchLength;
|
|
match.off = (int)(ip-matchPtr);
|
|
return match;
|
|
}
|
|
|
|
|
|
static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx,
|
|
const char* const source,
|
|
char* dst,
|
|
int* srcSizePtr,
|
|
int dstCapacity,
|
|
int const nbSearches,
|
|
size_t sufficient_len,
|
|
const limitedOutput_directive limit,
|
|
int const fullUpdate,
|
|
const dictCtx_directive dict,
|
|
const HCfavor_e favorDecSpeed)
|
|
{
|
|
int retval = 0;
|
|
#define TRAILING_LITERALS 3
|
|
#ifdef LZ4HC_HEAPMODE
|
|
LZ4HC_optimal_t* const opt = (LZ4HC_optimal_t*)ALLOC(sizeof(LZ4HC_optimal_t) * (LZ4_OPT_NUM + TRAILING_LITERALS));
|
|
#else
|
|
LZ4HC_optimal_t opt[LZ4_OPT_NUM + TRAILING_LITERALS]; /* ~64 KB, which is a bit large for stack... */
|
|
#endif
|
|
|
|
const BYTE* ip = (const BYTE*) source;
|
|
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* opSaved = (BYTE*) dst;
|
|
BYTE* oend = op + dstCapacity;
|
|
int ovml = MINMATCH; /* overflow - last sequence */
|
|
const BYTE* ovref = NULL;
|
|
|
|
/* init */
|
|
#ifdef LZ4HC_HEAPMODE
|
|
if (opt == NULL) goto _return_label;
|
|
#endif
|
|
DEBUGLOG(5, "LZ4HC_compress_optimal(dst=%p, dstCapa=%u)", dst, (unsigned)dstCapacity);
|
|
*srcSizePtr = 0;
|
|
if (limit == fillOutput) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */
|
|
if (sufficient_len >= LZ4_OPT_NUM) sufficient_len = LZ4_OPT_NUM-1;
|
|
|
|
/* Main Loop */
|
|
while (ip <= mflimit) {
|
|
int const llen = (int)(ip - anchor);
|
|
int best_mlen, best_off;
|
|
int cur, last_match_pos = 0;
|
|
|
|
LZ4HC_match_t const firstMatch = LZ4HC_FindLongerMatch(ctx, ip, matchlimit, MINMATCH-1, nbSearches, dict, favorDecSpeed);
|
|
if (firstMatch.len==0) { ip++; continue; }
|
|
|
|
if ((size_t)firstMatch.len > sufficient_len) {
|
|
/* good enough solution : immediate encoding */
|
|
int const firstML = firstMatch.len;
|
|
const BYTE* const matchPos = ip - firstMatch.off;
|
|
opSaved = op;
|
|
if ( LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), firstML, matchPos, limit, oend) ) { /* updates ip, op and anchor */
|
|
ovml = firstML;
|
|
ovref = matchPos;
|
|
goto _dest_overflow;
|
|
}
|
|
continue;
|
|
}
|
|
|
|
/* set prices for first positions (literals) */
|
|
{ int rPos;
|
|
for (rPos = 0 ; rPos < MINMATCH ; rPos++) {
|
|
int const cost = LZ4HC_literalsPrice(llen + rPos);
|
|
opt[rPos].mlen = 1;
|
|
opt[rPos].off = 0;
|
|
opt[rPos].litlen = llen + rPos;
|
|
opt[rPos].price = cost;
|
|
DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i) -- initial setup",
|
|
rPos, cost, opt[rPos].litlen);
|
|
} }
|
|
/* set prices using initial match */
|
|
{ int mlen = MINMATCH;
|
|
int const matchML = firstMatch.len; /* necessarily < sufficient_len < LZ4_OPT_NUM */
|
|
int const offset = firstMatch.off;
|
|
assert(matchML < LZ4_OPT_NUM);
|
|
for ( ; mlen <= matchML ; mlen++) {
|
|
int const cost = LZ4HC_sequencePrice(llen, mlen);
|
|
opt[mlen].mlen = mlen;
|
|
opt[mlen].off = offset;
|
|
opt[mlen].litlen = llen;
|
|
opt[mlen].price = cost;
|
|
DEBUGLOG(7, "rPos:%3i => price:%3i (matchlen=%i) -- initial setup",
|
|
mlen, cost, mlen);
|
|
} }
|
|
last_match_pos = firstMatch.len;
|
|
{ int addLit;
|
|
for (addLit = 1; addLit <= TRAILING_LITERALS; addLit ++) {
|
|
opt[last_match_pos+addLit].mlen = 1; /* literal */
|
|
opt[last_match_pos+addLit].off = 0;
|
|
opt[last_match_pos+addLit].litlen = addLit;
|
|
opt[last_match_pos+addLit].price = opt[last_match_pos].price + LZ4HC_literalsPrice(addLit);
|
|
DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i) -- initial setup",
|
|
last_match_pos+addLit, opt[last_match_pos+addLit].price, addLit);
|
|
} }
|
|
|
|
/* check further positions */
|
|
for (cur = 1; cur < last_match_pos; cur++) {
|
|
const BYTE* const curPtr = ip + cur;
|
|
LZ4HC_match_t newMatch;
|
|
|
|
if (curPtr > mflimit) break;
|
|
DEBUGLOG(7, "rPos:%u[%u] vs [%u]%u",
|
|
cur, opt[cur].price, opt[cur+1].price, cur+1);
|
|
if (fullUpdate) {
|
|
/* not useful to search here if next position has same (or lower) cost */
|
|
if ( (opt[cur+1].price <= opt[cur].price)
|
|
/* in some cases, next position has same cost, but cost rises sharply after, so a small match would still be beneficial */
|
|
&& (opt[cur+MINMATCH].price < opt[cur].price + 3/*min seq price*/) )
|
|
continue;
|
|
} else {
|
|
/* not useful to search here if next position has same (or lower) cost */
|
|
if (opt[cur+1].price <= opt[cur].price) continue;
|
|
}
|
|
|
|
DEBUGLOG(7, "search at rPos:%u", cur);
|
|
if (fullUpdate)
|
|
newMatch = LZ4HC_FindLongerMatch(ctx, curPtr, matchlimit, MINMATCH-1, nbSearches, dict, favorDecSpeed);
|
|
else
|
|
/* only test matches of minimum length; slightly faster, but misses a few bytes */
|
|
newMatch = LZ4HC_FindLongerMatch(ctx, curPtr, matchlimit, last_match_pos - cur, nbSearches, dict, favorDecSpeed);
|
|
if (!newMatch.len) continue;
|
|
|
|
if ( ((size_t)newMatch.len > sufficient_len)
|
|
|| (newMatch.len + cur >= LZ4_OPT_NUM) ) {
|
|
/* immediate encoding */
|
|
best_mlen = newMatch.len;
|
|
best_off = newMatch.off;
|
|
last_match_pos = cur + 1;
|
|
goto encode;
|
|
}
|
|
|
|
/* before match : set price with literals at beginning */
|
|
{ int const baseLitlen = opt[cur].litlen;
|
|
int litlen;
|
|
for (litlen = 1; litlen < MINMATCH; litlen++) {
|
|
int const price = opt[cur].price - LZ4HC_literalsPrice(baseLitlen) + LZ4HC_literalsPrice(baseLitlen+litlen);
|
|
int const pos = cur + litlen;
|
|
if (price < opt[pos].price) {
|
|
opt[pos].mlen = 1; /* literal */
|
|
opt[pos].off = 0;
|
|
opt[pos].litlen = baseLitlen+litlen;
|
|
opt[pos].price = price;
|
|
DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i)",
|
|
pos, price, opt[pos].litlen);
|
|
} } }
|
|
|
|
/* set prices using match at position = cur */
|
|
{ int const matchML = newMatch.len;
|
|
int ml = MINMATCH;
|
|
|
|
assert(cur + newMatch.len < LZ4_OPT_NUM);
|
|
for ( ; ml <= matchML ; ml++) {
|
|
int const pos = cur + ml;
|
|
int const offset = newMatch.off;
|
|
int price;
|
|
int ll;
|
|
DEBUGLOG(7, "testing price rPos %i (last_match_pos=%i)",
|
|
pos, last_match_pos);
|
|
if (opt[cur].mlen == 1) {
|
|
ll = opt[cur].litlen;
|
|
price = ((cur > ll) ? opt[cur - ll].price : 0)
|
|
+ LZ4HC_sequencePrice(ll, ml);
|
|
} else {
|
|
ll = 0;
|
|
price = opt[cur].price + LZ4HC_sequencePrice(0, ml);
|
|
}
|
|
|
|
assert((U32)favorDecSpeed <= 1);
|
|
if (pos > last_match_pos+TRAILING_LITERALS
|
|
|| price <= opt[pos].price - (int)favorDecSpeed) {
|
|
DEBUGLOG(7, "rPos:%3i => price:%3i (matchlen=%i)",
|
|
pos, price, ml);
|
|
assert(pos < LZ4_OPT_NUM);
|
|
if ( (ml == matchML) /* last pos of last match */
|
|
&& (last_match_pos < pos) )
|
|
last_match_pos = pos;
|
|
opt[pos].mlen = ml;
|
|
opt[pos].off = offset;
|
|
opt[pos].litlen = ll;
|
|
opt[pos].price = price;
|
|
} } }
|
|
/* complete following positions with literals */
|
|
{ int addLit;
|
|
for (addLit = 1; addLit <= TRAILING_LITERALS; addLit ++) {
|
|
opt[last_match_pos+addLit].mlen = 1; /* literal */
|
|
opt[last_match_pos+addLit].off = 0;
|
|
opt[last_match_pos+addLit].litlen = addLit;
|
|
opt[last_match_pos+addLit].price = opt[last_match_pos].price + LZ4HC_literalsPrice(addLit);
|
|
DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i)", last_match_pos+addLit, opt[last_match_pos+addLit].price, addLit);
|
|
} }
|
|
} /* for (cur = 1; cur <= last_match_pos; cur++) */
|
|
|
|
assert(last_match_pos < LZ4_OPT_NUM + TRAILING_LITERALS);
|
|
best_mlen = opt[last_match_pos].mlen;
|
|
best_off = opt[last_match_pos].off;
|
|
cur = last_match_pos - best_mlen;
|
|
|
|
encode: /* cur, last_match_pos, best_mlen, best_off must be set */
|
|
assert(cur < LZ4_OPT_NUM);
|
|
assert(last_match_pos >= 1); /* == 1 when only one candidate */
|
|
DEBUGLOG(6, "reverse traversal, looking for shortest path (last_match_pos=%i)", last_match_pos);
|
|
{ int candidate_pos = cur;
|
|
int selected_matchLength = best_mlen;
|
|
int selected_offset = best_off;
|
|
while (1) { /* from end to beginning */
|
|
int const next_matchLength = opt[candidate_pos].mlen; /* can be 1, means literal */
|
|
int const next_offset = opt[candidate_pos].off;
|
|
DEBUGLOG(7, "pos %i: sequence length %i", candidate_pos, selected_matchLength);
|
|
opt[candidate_pos].mlen = selected_matchLength;
|
|
opt[candidate_pos].off = selected_offset;
|
|
selected_matchLength = next_matchLength;
|
|
selected_offset = next_offset;
|
|
if (next_matchLength > candidate_pos) break; /* last match elected, first match to encode */
|
|
assert(next_matchLength > 0); /* can be 1, means literal */
|
|
candidate_pos -= next_matchLength;
|
|
} }
|
|
|
|
/* encode all recorded sequences in order */
|
|
{ int rPos = 0; /* relative position (to ip) */
|
|
while (rPos < last_match_pos) {
|
|
int const ml = opt[rPos].mlen;
|
|
int const offset = opt[rPos].off;
|
|
if (ml == 1) { ip++; rPos++; continue; } /* literal; note: can end up with several literals, in which case, skip them */
|
|
rPos += ml;
|
|
assert(ml >= MINMATCH);
|
|
assert((offset >= 1) && (offset <= LZ4_DISTANCE_MAX));
|
|
opSaved = op;
|
|
if ( LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ip - offset, limit, oend) ) { /* updates ip, op and anchor */
|
|
ovml = ml;
|
|
ovref = ip - offset;
|
|
goto _dest_overflow;
|
|
} } }
|
|
} /* while (ip <= mflimit) */
|
|
|
|
_last_literals:
|
|
/* Encode Last Literals */
|
|
{ size_t lastRunSize = (size_t)(iend - anchor); /* literals */
|
|
size_t llAdd = (lastRunSize + 255 - RUN_MASK) / 255;
|
|
size_t const totalSize = 1 + llAdd + lastRunSize;
|
|
if (limit == fillOutput) oend += LASTLITERALS; /* restore correct value */
|
|
if (limit && (op + totalSize > oend)) {
|
|
if (limit == limitedOutput) { /* Check output limit */
|
|
retval = 0;
|
|
goto _return_label;
|
|
}
|
|
/* adapt lastRunSize to fill 'dst' */
|
|
lastRunSize = (size_t)(oend - op) - 1 /*token*/;
|
|
llAdd = (lastRunSize + 256 - RUN_MASK) / 256;
|
|
lastRunSize -= llAdd;
|
|
}
|
|
DEBUGLOG(6, "Final literal run : %i literals", (int)lastRunSize);
|
|
ip = anchor + lastRunSize; /* can be != iend if limit==fillOutput */
|
|
|
|
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) - source);
|
|
retval = (int) ((char*)op-dst);
|
|
goto _return_label;
|
|
|
|
_dest_overflow:
|
|
if (limit == fillOutput) {
|
|
/* Assumption : ip, anchor, ovml and ovref must be set correctly */
|
|
size_t const ll = (size_t)(ip - anchor);
|
|
size_t const ll_addbytes = (ll + 240) / 255;
|
|
size_t const ll_totalCost = 1 + ll_addbytes + ll;
|
|
BYTE* const maxLitPos = oend - 3; /* 2 for offset, 1 for token */
|
|
DEBUGLOG(6, "Last sequence overflowing (only %i bytes remaining)", (int)(oend-1-opSaved));
|
|
op = opSaved; /* restore correct out pointer */
|
|
if (op + ll_totalCost <= maxLitPos) {
|
|
/* ll validated; now adjust match length */
|
|
size_t const bytesLeftForMl = (size_t)(maxLitPos - (op+ll_totalCost));
|
|
size_t const maxMlSize = MINMATCH + (ML_MASK-1) + (bytesLeftForMl * 255);
|
|
assert(maxMlSize < INT_MAX); assert(ovml >= 0);
|
|
if ((size_t)ovml > maxMlSize) ovml = (int)maxMlSize;
|
|
if ((oend + LASTLITERALS) - (op + ll_totalCost + 2) - 1 + ovml >= MFLIMIT) {
|
|
DEBUGLOG(6, "Space to end : %i + ml (%i)", (int)((oend + LASTLITERALS) - (op + ll_totalCost + 2) - 1), ovml);
|
|
DEBUGLOG(6, "Before : ip = %p, anchor = %p", ip, anchor);
|
|
LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ovml, ovref, notLimited, oend);
|
|
DEBUGLOG(6, "After : ip = %p, anchor = %p", ip, anchor);
|
|
} }
|
|
goto _last_literals;
|
|
}
|
|
_return_label:
|
|
#ifdef LZ4HC_HEAPMODE
|
|
FREEMEM(opt);
|
|
#endif
|
|
return retval;
|
|
}
|
|
/*
|
|
* LZ4 auto-framing library
|
|
* Copyright (C) 2011-2016, Yann Collet.
|
|
*
|
|
* BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are
|
|
* met:
|
|
*
|
|
* - Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* - Redistributions in binary form must reproduce the above
|
|
* copyright notice, this list of conditions and the following disclaimer
|
|
* in the documentation and/or other materials provided with the
|
|
* distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
* You can contact the author at :
|
|
* - LZ4 homepage : http://www.lz4.org
|
|
* - LZ4 source repository : https://github.com/lz4/lz4
|
|
*/
|
|
|
|
/* LZ4F is a stand-alone API to create LZ4-compressed Frames
|
|
* in full conformance with specification v1.6.1 .
|
|
* This library rely upon memory management capabilities (malloc, free)
|
|
* provided either by <stdlib.h>,
|
|
* or redirected towards another library of user's choice
|
|
* (see Memory Routines below).
|
|
*/
|
|
|
|
|
|
/*-************************************
|
|
* Compiler Options
|
|
**************************************/
|
|
#ifdef _MSC_VER /* Visual Studio */
|
|
# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
|
|
#endif
|
|
|
|
|
|
/*-************************************
|
|
* Tuning parameters
|
|
**************************************/
|
|
/*
|
|
* LZ4F_HEAPMODE :
|
|
* Select how default compression functions will allocate memory for their hash table,
|
|
* in memory stack (0:default, fastest), or in memory heap (1:requires malloc()).
|
|
*/
|
|
#ifndef LZ4F_HEAPMODE
|
|
# define LZ4F_HEAPMODE 0
|
|
#endif
|
|
|
|
|
|
/*-************************************
|
|
* Memory routines
|
|
**************************************/
|
|
/*
|
|
* User may redirect invocations of
|
|
* malloc(), calloc() and free()
|
|
* towards another library or solution of their choice
|
|
* by modifying below section.
|
|
*/
|
|
#ifndef LZ4_SRC_INCLUDED /* avoid redefinition when sources are coalesced */
|
|
# include <stdlib.h> /* malloc, calloc, free */
|
|
# define ALLOC(s) malloc(s)
|
|
# define ALLOC_AND_ZERO(s) calloc(1,(s))
|
|
# define FREEMEM(p) free(p)
|
|
#endif
|
|
|
|
#include <string.h> /* memset, memcpy, memmove */
|
|
#ifndef LZ4_SRC_INCLUDED /* avoid redefinition when sources are coalesced */
|
|
# define MEM_INIT(p,v,s) memset((p),(v),(s))
|
|
#endif
|
|
|
|
|
|
/*-************************************
|
|
* Library declarations
|
|
**************************************/
|
|
#define LZ4F_STATIC_LINKING_ONLY
|
|
#include "lz4frame.h"
|
|
#define LZ4_STATIC_LINKING_ONLY
|
|
#include "lz4.h"
|
|
#define LZ4_HC_STATIC_LINKING_ONLY
|
|
#include "lz4hc.h"
|
|
#define XXH_STATIC_LINKING_ONLY
|
|
#include "xxhash.h"
|
|
|
|
|
|
/*-************************************
|
|
* Debug
|
|
**************************************/
|
|
#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=1)
|
|
# include <assert.h>
|
|
#else
|
|
# ifndef assert
|
|
# define assert(condition) ((void)0)
|
|
# endif
|
|
#endif
|
|
|
|
#define LZ4F_STATIC_ASSERT(c) { enum { LZ4F_static_assert = 1/(int)(!!(c)) }; } /* use only *after* variable declarations */
|
|
|
|
#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=2) && !defined(DEBUGLOG)
|
|
# include <stdio.h>
|
|
static int g_debuglog_enable = 1;
|
|
# define DEBUGLOG(l, ...) { \
|
|
if ((g_debuglog_enable) && (l<=LZ4_DEBUG)) { \
|
|
fprintf(stderr, __FILE__ ": "); \
|
|
fprintf(stderr, __VA_ARGS__); \
|
|
fprintf(stderr, " \n"); \
|
|
} }
|
|
#else
|
|
# define DEBUGLOG(l, ...) {} /* disabled */
|
|
#endif
|
|
|
|
|
|
/*-************************************
|
|
* Basic Types
|
|
**************************************/
|
|
#if !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
|
|
# include <stdint.h>
|
|
typedef uint8_t BYTE;
|
|
typedef uint16_t U16;
|
|
typedef uint32_t U32;
|
|
typedef int32_t S32;
|
|
typedef uint64_t U64;
|
|
#else
|
|
typedef unsigned char BYTE;
|
|
typedef unsigned short U16;
|
|
typedef unsigned int U32;
|
|
typedef signed int S32;
|
|
typedef unsigned long long U64;
|
|
#endif
|
|
|
|
|
|
/* unoptimized version; solves endianess & alignment issues */
|
|
static U32 LZ4F_readLE32 (const void* src)
|
|
{
|
|
const BYTE* const srcPtr = (const BYTE*)src;
|
|
U32 value32 = srcPtr[0];
|
|
value32 += ((U32)srcPtr[1])<< 8;
|
|
value32 += ((U32)srcPtr[2])<<16;
|
|
value32 += ((U32)srcPtr[3])<<24;
|
|
return value32;
|
|
}
|
|
|
|
static void LZ4F_writeLE32 (void* dst, U32 value32)
|
|
{
|
|
BYTE* const dstPtr = (BYTE*)dst;
|
|
dstPtr[0] = (BYTE)value32;
|
|
dstPtr[1] = (BYTE)(value32 >> 8);
|
|
dstPtr[2] = (BYTE)(value32 >> 16);
|
|
dstPtr[3] = (BYTE)(value32 >> 24);
|
|
}
|
|
|
|
static U64 LZ4F_readLE64 (const void* src)
|
|
{
|
|
const BYTE* const srcPtr = (const BYTE*)src;
|
|
U64 value64 = srcPtr[0];
|
|
value64 += ((U64)srcPtr[1]<<8);
|
|
value64 += ((U64)srcPtr[2]<<16);
|
|
value64 += ((U64)srcPtr[3]<<24);
|
|
value64 += ((U64)srcPtr[4]<<32);
|
|
value64 += ((U64)srcPtr[5]<<40);
|
|
value64 += ((U64)srcPtr[6]<<48);
|
|
value64 += ((U64)srcPtr[7]<<56);
|
|
return value64;
|
|
}
|
|
|
|
static void LZ4F_writeLE64 (void* dst, U64 value64)
|
|
{
|
|
BYTE* const dstPtr = (BYTE*)dst;
|
|
dstPtr[0] = (BYTE)value64;
|
|
dstPtr[1] = (BYTE)(value64 >> 8);
|
|
dstPtr[2] = (BYTE)(value64 >> 16);
|
|
dstPtr[3] = (BYTE)(value64 >> 24);
|
|
dstPtr[4] = (BYTE)(value64 >> 32);
|
|
dstPtr[5] = (BYTE)(value64 >> 40);
|
|
dstPtr[6] = (BYTE)(value64 >> 48);
|
|
dstPtr[7] = (BYTE)(value64 >> 56);
|
|
}
|
|
|
|
|
|
/*-************************************
|
|
* Constants
|
|
**************************************/
|
|
#ifndef LZ4_SRC_INCLUDED /* avoid double definition */
|
|
# define KB *(1<<10)
|
|
# define MB *(1<<20)
|
|
# define GB *(1<<30)
|
|
#endif
|
|
|
|
#define _1BIT 0x01
|
|
#define _2BITS 0x03
|
|
#define _3BITS 0x07
|
|
#define _4BITS 0x0F
|
|
#define _8BITS 0xFF
|
|
|
|
#define LZ4F_MAGIC_SKIPPABLE_START 0x184D2A50U
|
|
#define LZ4F_MAGICNUMBER 0x184D2204U
|
|
#define LZ4F_BLOCKUNCOMPRESSED_FLAG 0x80000000U
|
|
#define LZ4F_BLOCKSIZEID_DEFAULT LZ4F_max64KB
|
|
|
|
static const size_t minFHSize = LZ4F_HEADER_SIZE_MIN; /* 7 */
|
|
static const size_t maxFHSize = LZ4F_HEADER_SIZE_MAX; /* 19 */
|
|
static const size_t BHSize = LZ4F_BLOCK_HEADER_SIZE; /* block header : size, and compress flag */
|
|
static const size_t BFSize = LZ4F_BLOCK_CHECKSUM_SIZE; /* block footer : checksum (optional) */
|
|
|
|
|
|
/*-************************************
|
|
* Structures and local types
|
|
**************************************/
|
|
typedef struct LZ4F_cctx_s
|
|
{
|
|
LZ4F_preferences_t prefs;
|
|
U32 version;
|
|
U32 cStage;
|
|
const LZ4F_CDict* cdict;
|
|
size_t maxBlockSize;
|
|
size_t maxBufferSize;
|
|
BYTE* tmpBuff;
|
|
BYTE* tmpIn;
|
|
size_t tmpInSize;
|
|
U64 totalInSize;
|
|
XXH32_state_t xxh;
|
|
void* lz4CtxPtr;
|
|
U16 lz4CtxAlloc; /* sized for: 0 = none, 1 = lz4 ctx, 2 = lz4hc ctx */
|
|
U16 lz4CtxState; /* in use as: 0 = none, 1 = lz4 ctx, 2 = lz4hc ctx */
|
|
} LZ4F_cctx_t;
|
|
|
|
|
|
/*-************************************
|
|
* Error management
|
|
**************************************/
|
|
#define LZ4F_GENERATE_STRING(STRING) #STRING,
|
|
static const char* LZ4F_errorStrings[] = { LZ4F_LIST_ERRORS(LZ4F_GENERATE_STRING) };
|
|
|
|
|
|
unsigned LZ4F_isError(LZ4F_errorCode_t code)
|
|
{
|
|
return (code > (LZ4F_errorCode_t)(-LZ4F_ERROR_maxCode));
|
|
}
|
|
|
|
const char* LZ4F_getErrorName(LZ4F_errorCode_t code)
|
|
{
|
|
static const char* codeError = "Unspecified error code";
|
|
if (LZ4F_isError(code)) return LZ4F_errorStrings[-(int)(code)];
|
|
return codeError;
|
|
}
|
|
|
|
LZ4F_errorCodes LZ4F_getErrorCode(size_t functionResult)
|
|
{
|
|
if (!LZ4F_isError(functionResult)) return LZ4F_OK_NoError;
|
|
return (LZ4F_errorCodes)(-(ptrdiff_t)functionResult);
|
|
}
|
|
|
|
static LZ4F_errorCode_t err0r(LZ4F_errorCodes code)
|
|
{
|
|
/* A compilation error here means sizeof(ptrdiff_t) is not large enough */
|
|
LZ4F_STATIC_ASSERT(sizeof(ptrdiff_t) >= sizeof(size_t));
|
|
return (LZ4F_errorCode_t)-(ptrdiff_t)code;
|
|
}
|
|
|
|
unsigned LZ4F_getVersion(void) { return LZ4F_VERSION; }
|
|
|
|
int LZ4F_compressionLevel_max(void) { return LZ4HC_CLEVEL_MAX; }
|
|
|
|
size_t LZ4F_getBlockSize(unsigned blockSizeID)
|
|
{
|
|
static const size_t blockSizes[4] = { 64 KB, 256 KB, 1 MB, 4 MB };
|
|
|
|
if (blockSizeID == 0) blockSizeID = LZ4F_BLOCKSIZEID_DEFAULT;
|
|
if (blockSizeID < LZ4F_max64KB || blockSizeID > LZ4F_max4MB)
|
|
return err0r(LZ4F_ERROR_maxBlockSize_invalid);
|
|
blockSizeID -= LZ4F_max64KB;
|
|
return blockSizes[blockSizeID];
|
|
}
|
|
|
|
/*-************************************
|
|
* Private functions
|
|
**************************************/
|
|
#define MIN(a,b) ( (a) < (b) ? (a) : (b) )
|
|
|
|
static BYTE LZ4F_headerChecksum (const void* header, size_t length)
|
|
{
|
|
U32 const xxh = XXH32(header, length, 0);
|
|
return (BYTE)(xxh >> 8);
|
|
}
|
|
|
|
|
|
/*-************************************
|
|
* Simple-pass compression functions
|
|
**************************************/
|
|
static LZ4F_blockSizeID_t LZ4F_optimalBSID(const LZ4F_blockSizeID_t requestedBSID,
|
|
const size_t srcSize)
|
|
{
|
|
LZ4F_blockSizeID_t proposedBSID = LZ4F_max64KB;
|
|
size_t maxBlockSize = 64 KB;
|
|
while (requestedBSID > proposedBSID) {
|
|
if (srcSize <= maxBlockSize)
|
|
return proposedBSID;
|
|
proposedBSID = (LZ4F_blockSizeID_t)((int)proposedBSID + 1);
|
|
maxBlockSize <<= 2;
|
|
}
|
|
return requestedBSID;
|
|
}
|
|
|
|
/*! LZ4F_compressBound_internal() :
|
|
* Provides dstCapacity given a srcSize to guarantee operation success in worst case situations.
|
|
* prefsPtr is optional : if NULL is provided, preferences will be set to cover worst case scenario.
|
|
* @return is always the same for a srcSize and prefsPtr, so it can be relied upon to size reusable buffers.
|
|
* When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() operations.
|
|
*/
|
|
static size_t LZ4F_compressBound_internal(size_t srcSize,
|
|
const LZ4F_preferences_t* preferencesPtr,
|
|
size_t alreadyBuffered)
|
|
{
|
|
LZ4F_preferences_t prefsNull = LZ4F_INIT_PREFERENCES;
|
|
prefsNull.frameInfo.contentChecksumFlag = LZ4F_contentChecksumEnabled; /* worst case */
|
|
prefsNull.frameInfo.blockChecksumFlag = LZ4F_blockChecksumEnabled; /* worst case */
|
|
{ const LZ4F_preferences_t* const prefsPtr = (preferencesPtr==NULL) ? &prefsNull : preferencesPtr;
|
|
U32 const flush = prefsPtr->autoFlush | (srcSize==0);
|
|
LZ4F_blockSizeID_t const blockID = prefsPtr->frameInfo.blockSizeID;
|
|
size_t const blockSize = LZ4F_getBlockSize(blockID);
|
|
size_t const maxBuffered = blockSize - 1;
|
|
size_t const bufferedSize = MIN(alreadyBuffered, maxBuffered);
|
|
size_t const maxSrcSize = srcSize + bufferedSize;
|
|
unsigned const nbFullBlocks = (unsigned)(maxSrcSize / blockSize);
|
|
size_t const partialBlockSize = maxSrcSize & (blockSize-1);
|
|
size_t const lastBlockSize = flush ? partialBlockSize : 0;
|
|
unsigned const nbBlocks = nbFullBlocks + (lastBlockSize>0);
|
|
|
|
size_t const blockCRCSize = BFSize * prefsPtr->frameInfo.blockChecksumFlag;
|
|
size_t const frameEnd = BHSize + (prefsPtr->frameInfo.contentChecksumFlag*BFSize);
|
|
|
|
return ((BHSize + blockCRCSize) * nbBlocks) +
|
|
(blockSize * nbFullBlocks) + lastBlockSize + frameEnd;
|
|
}
|
|
}
|
|
|
|
size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr)
|
|
{
|
|
LZ4F_preferences_t prefs;
|
|
size_t const headerSize = maxFHSize; /* max header size, including optional fields */
|
|
|
|
if (preferencesPtr!=NULL) prefs = *preferencesPtr;
|
|
else MEM_INIT(&prefs, 0, sizeof(prefs));
|
|
prefs.autoFlush = 1;
|
|
|
|
return headerSize + LZ4F_compressBound_internal(srcSize, &prefs, 0);;
|
|
}
|
|
|
|
|
|
/*! LZ4F_compressFrame_usingCDict() :
|
|
* Compress srcBuffer using a dictionary, in a single step.
|
|
* cdict can be NULL, in which case, no dictionary is used.
|
|
* dstBuffer MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr).
|
|
* The LZ4F_preferences_t structure is optional : you may provide NULL as argument,
|
|
* however, it's the only way to provide a dictID, so it's not recommended.
|
|
* @return : number of bytes written into dstBuffer,
|
|
* or an error code if it fails (can be tested using LZ4F_isError())
|
|
*/
|
|
size_t LZ4F_compressFrame_usingCDict(LZ4F_cctx* cctx,
|
|
void* dstBuffer, size_t dstCapacity,
|
|
const void* srcBuffer, size_t srcSize,
|
|
const LZ4F_CDict* cdict,
|
|
const LZ4F_preferences_t* preferencesPtr)
|
|
{
|
|
LZ4F_preferences_t prefs;
|
|
LZ4F_compressOptions_t options;
|
|
BYTE* const dstStart = (BYTE*) dstBuffer;
|
|
BYTE* dstPtr = dstStart;
|
|
BYTE* const dstEnd = dstStart + dstCapacity;
|
|
|
|
if (preferencesPtr!=NULL)
|
|
prefs = *preferencesPtr;
|
|
else
|
|
MEM_INIT(&prefs, 0, sizeof(prefs));
|
|
if (prefs.frameInfo.contentSize != 0)
|
|
prefs.frameInfo.contentSize = (U64)srcSize; /* auto-correct content size if selected (!=0) */
|
|
|
|
prefs.frameInfo.blockSizeID = LZ4F_optimalBSID(prefs.frameInfo.blockSizeID, srcSize);
|
|
prefs.autoFlush = 1;
|
|
if (srcSize <= LZ4F_getBlockSize(prefs.frameInfo.blockSizeID))
|
|
prefs.frameInfo.blockMode = LZ4F_blockIndependent; /* only one block => no need for inter-block link */
|
|
|
|
MEM_INIT(&options, 0, sizeof(options));
|
|
options.stableSrc = 1;
|
|
|
|
if (dstCapacity < LZ4F_compressFrameBound(srcSize, &prefs)) /* condition to guarantee success */
|
|
return err0r(LZ4F_ERROR_dstMaxSize_tooSmall);
|
|
|
|
{ size_t const headerSize = LZ4F_compressBegin_usingCDict(cctx, dstBuffer, dstCapacity, cdict, &prefs); /* write header */
|
|
if (LZ4F_isError(headerSize)) return headerSize;
|
|
dstPtr += headerSize; /* header size */ }
|
|
|
|
assert(dstEnd >= dstPtr);
|
|
{ size_t const cSize = LZ4F_compressUpdate(cctx, dstPtr, (size_t)(dstEnd-dstPtr), srcBuffer, srcSize, &options);
|
|
if (LZ4F_isError(cSize)) return cSize;
|
|
dstPtr += cSize; }
|
|
|
|
assert(dstEnd >= dstPtr);
|
|
{ size_t const tailSize = LZ4F_compressEnd(cctx, dstPtr, (size_t)(dstEnd-dstPtr), &options); /* flush last block, and generate suffix */
|
|
if (LZ4F_isError(tailSize)) return tailSize;
|
|
dstPtr += tailSize; }
|
|
|
|
assert(dstEnd >= dstStart);
|
|
return (size_t)(dstPtr - dstStart);
|
|
}
|
|
|
|
|
|
/*! LZ4F_compressFrame() :
|
|
* Compress an entire srcBuffer into a valid LZ4 frame, in a single step.
|
|
* dstBuffer MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr).
|
|
* The LZ4F_preferences_t structure is optional : you can provide NULL as argument. All preferences will be set to default.
|
|
* @return : number of bytes written into dstBuffer.
|
|
* or an error code if it fails (can be tested using LZ4F_isError())
|
|
*/
|
|
size_t LZ4F_compressFrame(void* dstBuffer, size_t dstCapacity,
|
|
const void* srcBuffer, size_t srcSize,
|
|
const LZ4F_preferences_t* preferencesPtr)
|
|
{
|
|
size_t result;
|
|
#if (LZ4F_HEAPMODE)
|
|
LZ4F_cctx_t *cctxPtr;
|
|
result = LZ4F_createCompressionContext(&cctxPtr, LZ4F_VERSION);
|
|
if (LZ4F_isError(result)) return result;
|
|
#else
|
|
LZ4F_cctx_t cctx;
|
|
LZ4_stream_t lz4ctx;
|
|
LZ4F_cctx_t *cctxPtr = &cctx;
|
|
|
|
DEBUGLOG(4, "LZ4F_compressFrame");
|
|
MEM_INIT(&cctx, 0, sizeof(cctx));
|
|
cctx.version = LZ4F_VERSION;
|
|
cctx.maxBufferSize = 5 MB; /* mess with real buffer size to prevent dynamic allocation; works only because autoflush==1 & stableSrc==1 */
|
|
if (preferencesPtr == NULL ||
|
|
preferencesPtr->compressionLevel < LZ4HC_CLEVEL_MIN)
|
|
{
|
|
LZ4_initStream(&lz4ctx, sizeof(lz4ctx));
|
|
cctxPtr->lz4CtxPtr = &lz4ctx;
|
|
cctxPtr->lz4CtxAlloc = 1;
|
|
cctxPtr->lz4CtxState = 1;
|
|
}
|
|
#endif
|
|
|
|
result = LZ4F_compressFrame_usingCDict(cctxPtr, dstBuffer, dstCapacity,
|
|
srcBuffer, srcSize,
|
|
NULL, preferencesPtr);
|
|
|
|
#if (LZ4F_HEAPMODE)
|
|
LZ4F_freeCompressionContext(cctxPtr);
|
|
#else
|
|
if (preferencesPtr != NULL &&
|
|
preferencesPtr->compressionLevel >= LZ4HC_CLEVEL_MIN)
|
|
{
|
|
FREEMEM(cctxPtr->lz4CtxPtr);
|
|
}
|
|
#endif
|
|
return result;
|
|
}
|
|
|
|
|
|
/*-***************************************************
|
|
* Dictionary compression
|
|
*****************************************************/
|
|
|
|
struct LZ4F_CDict_s {
|
|
void* dictContent;
|
|
LZ4_stream_t* fastCtx;
|
|
LZ4_streamHC_t* HCCtx;
|
|
}; /* typedef'd to LZ4F_CDict within lz4frame_static.h */
|
|
|
|
/*! LZ4F_createCDict() :
|
|
* When compressing multiple messages / blocks with the same dictionary, it's recommended to load it just once.
|
|
* LZ4F_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay.
|
|
* LZ4F_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only.
|
|
* `dictBuffer` can be released after LZ4F_CDict creation, since its content is copied within CDict
|
|
* @return : digested dictionary for compression, or NULL if failed */
|
|
LZ4F_CDict* LZ4F_createCDict(const void* dictBuffer, size_t dictSize)
|
|
{
|
|
const char* dictStart = (const char*)dictBuffer;
|
|
LZ4F_CDict* cdict = (LZ4F_CDict*) ALLOC(sizeof(*cdict));
|
|
DEBUGLOG(4, "LZ4F_createCDict");
|
|
if (!cdict) return NULL;
|
|
if (dictSize > 64 KB) {
|
|
dictStart += dictSize - 64 KB;
|
|
dictSize = 64 KB;
|
|
}
|
|
cdict->dictContent = ALLOC(dictSize);
|
|
cdict->fastCtx = LZ4_createStream();
|
|
cdict->HCCtx = LZ4_createStreamHC();
|
|
if (!cdict->dictContent || !cdict->fastCtx || !cdict->HCCtx) {
|
|
LZ4F_freeCDict(cdict);
|
|
return NULL;
|
|
}
|
|
memcpy(cdict->dictContent, dictStart, dictSize);
|
|
LZ4_loadDict (cdict->fastCtx, (const char*)cdict->dictContent, (int)dictSize);
|
|
LZ4_setCompressionLevel(cdict->HCCtx, LZ4HC_CLEVEL_DEFAULT);
|
|
LZ4_loadDictHC(cdict->HCCtx, (const char*)cdict->dictContent, (int)dictSize);
|
|
return cdict;
|
|
}
|
|
|
|
void LZ4F_freeCDict(LZ4F_CDict* cdict)
|
|
{
|
|
if (cdict==NULL) return; /* support free on NULL */
|
|
FREEMEM(cdict->dictContent);
|
|
LZ4_freeStream(cdict->fastCtx);
|
|
LZ4_freeStreamHC(cdict->HCCtx);
|
|
FREEMEM(cdict);
|
|
}
|
|
|
|
|
|
/*-*********************************
|
|
* Advanced compression functions
|
|
***********************************/
|
|
|
|
/*! LZ4F_createCompressionContext() :
|
|
* The first thing to do is to create a compressionContext object, which will be used in all compression operations.
|
|
* This is achieved using LZ4F_createCompressionContext(), which takes as argument a version and an LZ4F_preferences_t structure.
|
|
* The version provided MUST be LZ4F_VERSION. It is intended to track potential incompatible differences between different binaries.
|
|
* The function will provide a pointer to an allocated LZ4F_compressionContext_t object.
|
|
* If the result LZ4F_errorCode_t is not OK_NoError, there was an error during context creation.
|
|
* Object can release its memory using LZ4F_freeCompressionContext();
|
|
*/
|
|
LZ4F_errorCode_t LZ4F_createCompressionContext(LZ4F_cctx** LZ4F_compressionContextPtr, unsigned version)
|
|
{
|
|
LZ4F_cctx_t* const cctxPtr = (LZ4F_cctx_t*)ALLOC_AND_ZERO(sizeof(LZ4F_cctx_t));
|
|
if (cctxPtr==NULL) return err0r(LZ4F_ERROR_allocation_failed);
|
|
|
|
cctxPtr->version = version;
|
|
cctxPtr->cStage = 0; /* Next stage : init stream */
|
|
|
|
*LZ4F_compressionContextPtr = cctxPtr;
|
|
|
|
return LZ4F_OK_NoError;
|
|
}
|
|
|
|
|
|
LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctxPtr)
|
|
{
|
|
if (cctxPtr != NULL) { /* support free on NULL */
|
|
FREEMEM(cctxPtr->lz4CtxPtr); /* note: LZ4_streamHC_t and LZ4_stream_t are simple POD types */
|
|
FREEMEM(cctxPtr->tmpBuff);
|
|
FREEMEM(cctxPtr);
|
|
}
|
|
|
|
return LZ4F_OK_NoError;
|
|
}
|
|
|
|
|
|
/**
|
|
* This function prepares the internal LZ4(HC) stream for a new compression,
|
|
* resetting the context and attaching the dictionary, if there is one.
|
|
*
|
|
* It needs to be called at the beginning of each independent compression
|
|
* stream (i.e., at the beginning of a frame in blockLinked mode, or at the
|
|
* beginning of each block in blockIndependent mode).
|
|
*/
|
|
static void LZ4F_initStream(void* ctx,
|
|
const LZ4F_CDict* cdict,
|
|
int level,
|
|
LZ4F_blockMode_t blockMode) {
|
|
if (level < LZ4HC_CLEVEL_MIN) {
|
|
if (cdict != NULL || blockMode == LZ4F_blockLinked) {
|
|
/* In these cases, we will call LZ4_compress_fast_continue(),
|
|
* which needs an already reset context. Otherwise, we'll call a
|
|
* one-shot API. The non-continued APIs internally perform their own
|
|
* resets at the beginning of their calls, where they know what
|
|
* tableType they need the context to be in. So in that case this
|
|
* would be misguided / wasted work. */
|
|
LZ4_resetStream_fast((LZ4_stream_t*)ctx);
|
|
}
|
|
LZ4_attach_dictionary((LZ4_stream_t *)ctx, cdict ? cdict->fastCtx : NULL);
|
|
} else {
|
|
LZ4_resetStreamHC_fast((LZ4_streamHC_t*)ctx, level);
|
|
LZ4_attach_HC_dictionary((LZ4_streamHC_t *)ctx, cdict ? cdict->HCCtx : NULL);
|
|
}
|
|
}
|
|
|
|
|
|
/*! LZ4F_compressBegin_usingCDict() :
|
|
* init streaming compression and writes frame header into dstBuffer.
|
|
* dstBuffer must be >= LZ4F_HEADER_SIZE_MAX bytes.
|
|
* @return : number of bytes written into dstBuffer for the header
|
|
* or an error code (can be tested using LZ4F_isError())
|
|
*/
|
|
size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr,
|
|
void* dstBuffer, size_t dstCapacity,
|
|
const LZ4F_CDict* cdict,
|
|
const LZ4F_preferences_t* preferencesPtr)
|
|
{
|
|
LZ4F_preferences_t prefNull;
|
|
BYTE* const dstStart = (BYTE*)dstBuffer;
|
|
BYTE* dstPtr = dstStart;
|
|
BYTE* headerStart;
|
|
|
|
if (dstCapacity < maxFHSize) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall);
|
|
MEM_INIT(&prefNull, 0, sizeof(prefNull));
|
|
if (preferencesPtr == NULL) preferencesPtr = &prefNull;
|
|
cctxPtr->prefs = *preferencesPtr;
|
|
|
|
/* Ctx Management */
|
|
{ U16 const ctxTypeID = (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) ? 1 : 2;
|
|
if (cctxPtr->lz4CtxAlloc < ctxTypeID) {
|
|
FREEMEM(cctxPtr->lz4CtxPtr);
|
|
if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) {
|
|
cctxPtr->lz4CtxPtr = LZ4_createStream();
|
|
} else {
|
|
cctxPtr->lz4CtxPtr = LZ4_createStreamHC();
|
|
}
|
|
if (cctxPtr->lz4CtxPtr == NULL)
|
|
return err0r(LZ4F_ERROR_allocation_failed);
|
|
cctxPtr->lz4CtxAlloc = ctxTypeID;
|
|
cctxPtr->lz4CtxState = ctxTypeID;
|
|
} else if (cctxPtr->lz4CtxState != ctxTypeID) {
|
|
/* otherwise, a sufficient buffer is allocated, but we need to
|
|
* reset it to the correct context type */
|
|
if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) {
|
|
LZ4_initStream((LZ4_stream_t *) cctxPtr->lz4CtxPtr, sizeof (LZ4_stream_t));
|
|
} else {
|
|
LZ4_initStreamHC((LZ4_streamHC_t *) cctxPtr->lz4CtxPtr, sizeof(LZ4_streamHC_t));
|
|
LZ4_setCompressionLevel((LZ4_streamHC_t *) cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel);
|
|
}
|
|
cctxPtr->lz4CtxState = ctxTypeID;
|
|
}
|
|
}
|
|
|
|
/* Buffer Management */
|
|
if (cctxPtr->prefs.frameInfo.blockSizeID == 0)
|
|
cctxPtr->prefs.frameInfo.blockSizeID = LZ4F_BLOCKSIZEID_DEFAULT;
|
|
cctxPtr->maxBlockSize = LZ4F_getBlockSize(cctxPtr->prefs.frameInfo.blockSizeID);
|
|
|
|
{ size_t const requiredBuffSize = preferencesPtr->autoFlush ?
|
|
((cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) ? 64 KB : 0) : /* only needs past data up to window size */
|
|
cctxPtr->maxBlockSize + ((cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) ? 128 KB : 0);
|
|
|
|
if (cctxPtr->maxBufferSize < requiredBuffSize) {
|
|
cctxPtr->maxBufferSize = 0;
|
|
FREEMEM(cctxPtr->tmpBuff);
|
|
cctxPtr->tmpBuff = (BYTE*)ALLOC_AND_ZERO(requiredBuffSize);
|
|
if (cctxPtr->tmpBuff == NULL) return err0r(LZ4F_ERROR_allocation_failed);
|
|
cctxPtr->maxBufferSize = requiredBuffSize;
|
|
} }
|
|
cctxPtr->tmpIn = cctxPtr->tmpBuff;
|
|
cctxPtr->tmpInSize = 0;
|
|
(void)XXH32_reset(&(cctxPtr->xxh), 0);
|
|
|
|
/* context init */
|
|
cctxPtr->cdict = cdict;
|
|
if (cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) {
|
|
/* frame init only for blockLinked : blockIndependent will be init at each block */
|
|
LZ4F_initStream(cctxPtr->lz4CtxPtr, cdict, cctxPtr->prefs.compressionLevel, LZ4F_blockLinked);
|
|
}
|
|
if (preferencesPtr->compressionLevel >= LZ4HC_CLEVEL_MIN) {
|
|
LZ4_favorDecompressionSpeed((LZ4_streamHC_t*)cctxPtr->lz4CtxPtr, (int)preferencesPtr->favorDecSpeed);
|
|
}
|
|
|
|
/* Magic Number */
|
|
LZ4F_writeLE32(dstPtr, LZ4F_MAGICNUMBER);
|
|
dstPtr += 4;
|
|
headerStart = dstPtr;
|
|
|
|
/* FLG Byte */
|
|
*dstPtr++ = (BYTE)(((1 & _2BITS) << 6) /* Version('01') */
|
|
+ ((cctxPtr->prefs.frameInfo.blockMode & _1BIT ) << 5)
|
|
+ ((cctxPtr->prefs.frameInfo.blockChecksumFlag & _1BIT ) << 4)
|
|
+ ((unsigned)(cctxPtr->prefs.frameInfo.contentSize > 0) << 3)
|
|
+ ((cctxPtr->prefs.frameInfo.contentChecksumFlag & _1BIT ) << 2)
|
|
+ (cctxPtr->prefs.frameInfo.dictID > 0) );
|
|
/* BD Byte */
|
|
*dstPtr++ = (BYTE)((cctxPtr->prefs.frameInfo.blockSizeID & _3BITS) << 4);
|
|
/* Optional Frame content size field */
|
|
if (cctxPtr->prefs.frameInfo.contentSize) {
|
|
LZ4F_writeLE64(dstPtr, cctxPtr->prefs.frameInfo.contentSize);
|
|
dstPtr += 8;
|
|
cctxPtr->totalInSize = 0;
|
|
}
|
|
/* Optional dictionary ID field */
|
|
if (cctxPtr->prefs.frameInfo.dictID) {
|
|
LZ4F_writeLE32(dstPtr, cctxPtr->prefs.frameInfo.dictID);
|
|
dstPtr += 4;
|
|
}
|
|
/* Header CRC Byte */
|
|
*dstPtr = LZ4F_headerChecksum(headerStart, (size_t)(dstPtr - headerStart));
|
|
dstPtr++;
|
|
|
|
cctxPtr->cStage = 1; /* header written, now request input data block */
|
|
return (size_t)(dstPtr - dstStart);
|
|
}
|
|
|
|
|
|
/*! LZ4F_compressBegin() :
|
|
* init streaming compression and writes frame header into dstBuffer.
|
|
* dstBuffer must be >= LZ4F_HEADER_SIZE_MAX bytes.
|
|
* preferencesPtr can be NULL, in which case default parameters are selected.
|
|
* @return : number of bytes written into dstBuffer for the header
|
|
* or an error code (can be tested using LZ4F_isError())
|
|
*/
|
|
size_t LZ4F_compressBegin(LZ4F_cctx* cctxPtr,
|
|
void* dstBuffer, size_t dstCapacity,
|
|
const LZ4F_preferences_t* preferencesPtr)
|
|
{
|
|
return LZ4F_compressBegin_usingCDict(cctxPtr, dstBuffer, dstCapacity,
|
|
NULL, preferencesPtr);
|
|
}
|
|
|
|
|
|
/* LZ4F_compressBound() :
|
|
* @return minimum capacity of dstBuffer for a given srcSize to handle worst case scenario.
|
|
* LZ4F_preferences_t structure is optional : if NULL, preferences will be set to cover worst case scenario.
|
|
* This function cannot fail.
|
|
*/
|
|
size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr)
|
|
{
|
|
if (preferencesPtr && preferencesPtr->autoFlush) {
|
|
return LZ4F_compressBound_internal(srcSize, preferencesPtr, 0);
|
|
}
|
|
return LZ4F_compressBound_internal(srcSize, preferencesPtr, (size_t)-1);
|
|
}
|
|
|
|
|
|
typedef int (*compressFunc_t)(void* ctx, const char* src, char* dst, int srcSize, int dstSize, int level, const LZ4F_CDict* cdict);
|
|
|
|
|
|
/*! LZ4F_makeBlock():
|
|
* compress a single block, add header and optional checksum.
|
|
* assumption : dst buffer capacity is >= BHSize + srcSize + crcSize
|
|
*/
|
|
static size_t LZ4F_makeBlock(void* dst,
|
|
const void* src, size_t srcSize,
|
|
compressFunc_t compress, void* lz4ctx, int level,
|
|
const LZ4F_CDict* cdict,
|
|
LZ4F_blockChecksum_t crcFlag)
|
|
{
|
|
BYTE* const cSizePtr = (BYTE*)dst;
|
|
U32 cSize = (U32)compress(lz4ctx, (const char*)src, (char*)(cSizePtr+BHSize),
|
|
(int)(srcSize), (int)(srcSize-1),
|
|
level, cdict);
|
|
if (cSize == 0) { /* compression failed */
|
|
DEBUGLOG(5, "LZ4F_makeBlock: compression failed, creating a raw block (size %u)", (U32)srcSize);
|
|
cSize = (U32)srcSize;
|
|
LZ4F_writeLE32(cSizePtr, cSize | LZ4F_BLOCKUNCOMPRESSED_FLAG);
|
|
memcpy(cSizePtr+BHSize, src, srcSize);
|
|
} else {
|
|
LZ4F_writeLE32(cSizePtr, cSize);
|
|
}
|
|
if (crcFlag) {
|
|
U32 const crc32 = XXH32(cSizePtr+BHSize, cSize, 0); /* checksum of compressed data */
|
|
LZ4F_writeLE32(cSizePtr+BHSize+cSize, crc32);
|
|
}
|
|
return BHSize + cSize + ((U32)crcFlag)*BFSize;
|
|
}
|
|
|
|
|
|
static int LZ4F_compressBlock(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
|
|
{
|
|
int const acceleration = (level < 0) ? -level + 1 : 1;
|
|
LZ4F_initStream(ctx, cdict, level, LZ4F_blockIndependent);
|
|
if (cdict) {
|
|
return LZ4_compress_fast_continue((LZ4_stream_t*)ctx, src, dst, srcSize, dstCapacity, acceleration);
|
|
} else {
|
|
return LZ4_compress_fast_extState_fastReset(ctx, src, dst, srcSize, dstCapacity, acceleration);
|
|
}
|
|
}
|
|
|
|
static int LZ4F_compressBlock_continue(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
|
|
{
|
|
int const acceleration = (level < 0) ? -level + 1 : 1;
|
|
(void)cdict; /* init once at beginning of frame */
|
|
return LZ4_compress_fast_continue((LZ4_stream_t*)ctx, src, dst, srcSize, dstCapacity, acceleration);
|
|
}
|
|
|
|
static int LZ4F_compressBlockHC(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
|
|
{
|
|
LZ4F_initStream(ctx, cdict, level, LZ4F_blockIndependent);
|
|
if (cdict) {
|
|
return LZ4_compress_HC_continue((LZ4_streamHC_t*)ctx, src, dst, srcSize, dstCapacity);
|
|
}
|
|
return LZ4_compress_HC_extStateHC_fastReset(ctx, src, dst, srcSize, dstCapacity, level);
|
|
}
|
|
|
|
static int LZ4F_compressBlockHC_continue(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
|
|
{
|
|
(void)level; (void)cdict; /* init once at beginning of frame */
|
|
return LZ4_compress_HC_continue((LZ4_streamHC_t*)ctx, src, dst, srcSize, dstCapacity);
|
|
}
|
|
|
|
static compressFunc_t LZ4F_selectCompression(LZ4F_blockMode_t blockMode, int level)
|
|
{
|
|
if (level < LZ4HC_CLEVEL_MIN) {
|
|
if (blockMode == LZ4F_blockIndependent) return LZ4F_compressBlock;
|
|
return LZ4F_compressBlock_continue;
|
|
}
|
|
if (blockMode == LZ4F_blockIndependent) return LZ4F_compressBlockHC;
|
|
return LZ4F_compressBlockHC_continue;
|
|
}
|
|
|
|
static int LZ4F_localSaveDict(LZ4F_cctx_t* cctxPtr)
|
|
{
|
|
if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN)
|
|
return LZ4_saveDict ((LZ4_stream_t*)(cctxPtr->lz4CtxPtr), (char*)(cctxPtr->tmpBuff), 64 KB);
|
|
return LZ4_saveDictHC ((LZ4_streamHC_t*)(cctxPtr->lz4CtxPtr), (char*)(cctxPtr->tmpBuff), 64 KB);
|
|
}
|
|
|
|
typedef enum { notDone, fromTmpBuffer, fromSrcBuffer } LZ4F_lastBlockStatus;
|
|
|
|
/*! LZ4F_compressUpdate() :
|
|
* LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
|
|
* dstBuffer MUST be >= LZ4F_compressBound(srcSize, preferencesPtr).
|
|
* LZ4F_compressOptions_t structure is optional : you can provide NULL as argument.
|
|
* @return : the number of bytes written into dstBuffer. It can be zero, meaning input data was just buffered.
|
|
* or an error code if it fails (which can be tested using LZ4F_isError())
|
|
*/
|
|
size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr,
|
|
void* dstBuffer, size_t dstCapacity,
|
|
const void* srcBuffer, size_t srcSize,
|
|
const LZ4F_compressOptions_t* compressOptionsPtr)
|
|
{
|
|
LZ4F_compressOptions_t cOptionsNull;
|
|
size_t const blockSize = cctxPtr->maxBlockSize;
|
|
const BYTE* srcPtr = (const BYTE*)srcBuffer;
|
|
const BYTE* const srcEnd = srcPtr + srcSize;
|
|
BYTE* const dstStart = (BYTE*)dstBuffer;
|
|
BYTE* dstPtr = dstStart;
|
|
LZ4F_lastBlockStatus lastBlockCompressed = notDone;
|
|
compressFunc_t const compress = LZ4F_selectCompression(cctxPtr->prefs.frameInfo.blockMode, cctxPtr->prefs.compressionLevel);
|
|
|
|
DEBUGLOG(4, "LZ4F_compressUpdate (srcSize=%zu)", srcSize);
|
|
|
|
if (cctxPtr->cStage != 1) return err0r(LZ4F_ERROR_GENERIC);
|
|
if (dstCapacity < LZ4F_compressBound_internal(srcSize, &(cctxPtr->prefs), cctxPtr->tmpInSize))
|
|
return err0r(LZ4F_ERROR_dstMaxSize_tooSmall);
|
|
MEM_INIT(&cOptionsNull, 0, sizeof(cOptionsNull));
|
|
if (compressOptionsPtr == NULL) compressOptionsPtr = &cOptionsNull;
|
|
|
|
/* complete tmp buffer */
|
|
if (cctxPtr->tmpInSize > 0) { /* some data already within tmp buffer */
|
|
size_t const sizeToCopy = blockSize - cctxPtr->tmpInSize;
|
|
if (sizeToCopy > srcSize) {
|
|
/* add src to tmpIn buffer */
|
|
memcpy(cctxPtr->tmpIn + cctxPtr->tmpInSize, srcBuffer, srcSize);
|
|
srcPtr = srcEnd;
|
|
cctxPtr->tmpInSize += srcSize;
|
|
/* still needs some CRC */
|
|
} else {
|
|
/* complete tmpIn block and then compress it */
|
|
lastBlockCompressed = fromTmpBuffer;
|
|
memcpy(cctxPtr->tmpIn + cctxPtr->tmpInSize, srcBuffer, sizeToCopy);
|
|
srcPtr += sizeToCopy;
|
|
|
|
dstPtr += LZ4F_makeBlock(dstPtr,
|
|
cctxPtr->tmpIn, blockSize,
|
|
compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
|
|
cctxPtr->cdict,
|
|
cctxPtr->prefs.frameInfo.blockChecksumFlag);
|
|
|
|
if (cctxPtr->prefs.frameInfo.blockMode==LZ4F_blockLinked) cctxPtr->tmpIn += blockSize;
|
|
cctxPtr->tmpInSize = 0;
|
|
}
|
|
}
|
|
|
|
while ((size_t)(srcEnd - srcPtr) >= blockSize) {
|
|
/* compress full blocks */
|
|
lastBlockCompressed = fromSrcBuffer;
|
|
dstPtr += LZ4F_makeBlock(dstPtr,
|
|
srcPtr, blockSize,
|
|
compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
|
|
cctxPtr->cdict,
|
|
cctxPtr->prefs.frameInfo.blockChecksumFlag);
|
|
srcPtr += blockSize;
|
|
}
|
|
|
|
if ((cctxPtr->prefs.autoFlush) && (srcPtr < srcEnd)) {
|
|
/* compress remaining input < blockSize */
|
|
lastBlockCompressed = fromSrcBuffer;
|
|
dstPtr += LZ4F_makeBlock(dstPtr,
|
|
srcPtr, (size_t)(srcEnd - srcPtr),
|
|
compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
|
|
cctxPtr->cdict,
|
|
cctxPtr->prefs.frameInfo.blockChecksumFlag);
|
|
srcPtr = srcEnd;
|
|
}
|
|
|
|
/* preserve dictionary if necessary */
|
|
if ((cctxPtr->prefs.frameInfo.blockMode==LZ4F_blockLinked) && (lastBlockCompressed==fromSrcBuffer)) {
|
|
if (compressOptionsPtr->stableSrc) {
|
|
cctxPtr->tmpIn = cctxPtr->tmpBuff;
|
|
} else {
|
|
int const realDictSize = LZ4F_localSaveDict(cctxPtr);
|
|
if (realDictSize==0) return err0r(LZ4F_ERROR_GENERIC);
|
|
cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize;
|
|
}
|
|
}
|
|
|
|
/* keep tmpIn within limits */
|
|
if ((cctxPtr->tmpIn + blockSize) > (cctxPtr->tmpBuff + cctxPtr->maxBufferSize) /* necessarily LZ4F_blockLinked && lastBlockCompressed==fromTmpBuffer */
|
|
&& !(cctxPtr->prefs.autoFlush))
|
|
{
|
|
int const realDictSize = LZ4F_localSaveDict(cctxPtr);
|
|
cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize;
|
|
}
|
|
|
|
/* some input data left, necessarily < blockSize */
|
|
if (srcPtr < srcEnd) {
|
|
/* fill tmp buffer */
|
|
size_t const sizeToCopy = (size_t)(srcEnd - srcPtr);
|
|
memcpy(cctxPtr->tmpIn, srcPtr, sizeToCopy);
|
|
cctxPtr->tmpInSize = sizeToCopy;
|
|
}
|
|
|
|
if (cctxPtr->prefs.frameInfo.contentChecksumFlag == LZ4F_contentChecksumEnabled)
|
|
(void)XXH32_update(&(cctxPtr->xxh), srcBuffer, srcSize);
|
|
|
|
cctxPtr->totalInSize += srcSize;
|
|
return (size_t)(dstPtr - dstStart);
|
|
}
|
|
|
|
|
|
/*! LZ4F_flush() :
|
|
* When compressed data must be sent immediately, without waiting for a block to be filled,
|
|
* invoke LZ4_flush(), which will immediately compress any remaining data stored within LZ4F_cctx.
|
|
* The result of the function is the number of bytes written into dstBuffer.
|
|
* It can be zero, this means there was no data left within LZ4F_cctx.
|
|
* The function outputs an error code if it fails (can be tested using LZ4F_isError())
|
|
* LZ4F_compressOptions_t* is optional. NULL is a valid argument.
|
|
*/
|
|
size_t LZ4F_flush(LZ4F_cctx* cctxPtr,
|
|
void* dstBuffer, size_t dstCapacity,
|
|
const LZ4F_compressOptions_t* compressOptionsPtr)
|
|
{
|
|
BYTE* const dstStart = (BYTE*)dstBuffer;
|
|
BYTE* dstPtr = dstStart;
|
|
compressFunc_t compress;
|
|
|
|
if (cctxPtr->tmpInSize == 0) return 0; /* nothing to flush */
|
|
if (cctxPtr->cStage != 1) return err0r(LZ4F_ERROR_GENERIC);
|
|
if (dstCapacity < (cctxPtr->tmpInSize + BHSize + BFSize))
|
|
return err0r(LZ4F_ERROR_dstMaxSize_tooSmall);
|
|
(void)compressOptionsPtr; /* not yet useful */
|
|
|
|
/* select compression function */
|
|
compress = LZ4F_selectCompression(cctxPtr->prefs.frameInfo.blockMode, cctxPtr->prefs.compressionLevel);
|
|
|
|
/* compress tmp buffer */
|
|
dstPtr += LZ4F_makeBlock(dstPtr,
|
|
cctxPtr->tmpIn, cctxPtr->tmpInSize,
|
|
compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
|
|
cctxPtr->cdict,
|
|
cctxPtr->prefs.frameInfo.blockChecksumFlag);
|
|
assert(((void)"flush overflows dstBuffer!", (size_t)(dstPtr - dstStart) <= dstCapacity));
|
|
|
|
if (cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked)
|
|
cctxPtr->tmpIn += cctxPtr->tmpInSize;
|
|
cctxPtr->tmpInSize = 0;
|
|
|
|
/* keep tmpIn within limits */
|
|
if ((cctxPtr->tmpIn + cctxPtr->maxBlockSize) > (cctxPtr->tmpBuff + cctxPtr->maxBufferSize)) { /* necessarily LZ4F_blockLinked */
|
|
int const realDictSize = LZ4F_localSaveDict(cctxPtr);
|
|
cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize;
|
|
}
|
|
|
|
return (size_t)(dstPtr - dstStart);
|
|
}
|
|
|
|
|
|
/*! LZ4F_compressEnd() :
|
|
* When you want to properly finish the compressed frame, just call LZ4F_compressEnd().
|
|
* It will flush whatever data remained within compressionContext (like LZ4_flush())
|
|
* but also properly finalize the frame, with an endMark and an (optional) checksum.
|
|
* LZ4F_compressOptions_t structure is optional : you can provide NULL as argument.
|
|
* @return: the number of bytes written into dstBuffer (necessarily >= 4 (endMark size))
|
|
* or an error code if it fails (can be tested using LZ4F_isError())
|
|
* The context can then be used again to compress a new frame, starting with LZ4F_compressBegin().
|
|
*/
|
|
size_t LZ4F_compressEnd(LZ4F_cctx* cctxPtr,
|
|
void* dstBuffer, size_t dstCapacity,
|
|
const LZ4F_compressOptions_t* compressOptionsPtr)
|
|
{
|
|
BYTE* const dstStart = (BYTE*)dstBuffer;
|
|
BYTE* dstPtr = dstStart;
|
|
|
|
size_t const flushSize = LZ4F_flush(cctxPtr, dstBuffer, dstCapacity, compressOptionsPtr);
|
|
DEBUGLOG(5,"LZ4F_compressEnd: dstCapacity=%u", (unsigned)dstCapacity);
|
|
if (LZ4F_isError(flushSize)) return flushSize;
|
|
dstPtr += flushSize;
|
|
|
|
assert(flushSize <= dstCapacity);
|
|
dstCapacity -= flushSize;
|
|
|
|
if (dstCapacity < 4) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall);
|
|
LZ4F_writeLE32(dstPtr, 0);
|
|
dstPtr += 4; /* endMark */
|
|
|
|
if (cctxPtr->prefs.frameInfo.contentChecksumFlag == LZ4F_contentChecksumEnabled) {
|
|
U32 const xxh = XXH32_digest(&(cctxPtr->xxh));
|
|
if (dstCapacity < 8) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall);
|
|
DEBUGLOG(5,"Writing 32-bit content checksum");
|
|
LZ4F_writeLE32(dstPtr, xxh);
|
|
dstPtr+=4; /* content Checksum */
|
|
}
|
|
|
|
cctxPtr->cStage = 0; /* state is now re-usable (with identical preferences) */
|
|
cctxPtr->maxBufferSize = 0; /* reuse HC context */
|
|
|
|
if (cctxPtr->prefs.frameInfo.contentSize) {
|
|
if (cctxPtr->prefs.frameInfo.contentSize != cctxPtr->totalInSize)
|
|
return err0r(LZ4F_ERROR_frameSize_wrong);
|
|
}
|
|
|
|
return (size_t)(dstPtr - dstStart);
|
|
}
|
|
|
|
|
|
/*-***************************************************
|
|
* Frame Decompression
|
|
*****************************************************/
|
|
|
|
typedef enum {
|
|
dstage_getFrameHeader=0, dstage_storeFrameHeader,
|
|
dstage_init,
|
|
dstage_getBlockHeader, dstage_storeBlockHeader,
|
|
dstage_copyDirect, dstage_getBlockChecksum,
|
|
dstage_getCBlock, dstage_storeCBlock,
|
|
dstage_flushOut,
|
|
dstage_getSuffix, dstage_storeSuffix,
|
|
dstage_getSFrameSize, dstage_storeSFrameSize,
|
|
dstage_skipSkippable
|
|
} dStage_t;
|
|
|
|
struct LZ4F_dctx_s {
|
|
LZ4F_frameInfo_t frameInfo;
|
|
U32 version;
|
|
dStage_t dStage;
|
|
U64 frameRemainingSize;
|
|
size_t maxBlockSize;
|
|
size_t maxBufferSize;
|
|
BYTE* tmpIn;
|
|
size_t tmpInSize;
|
|
size_t tmpInTarget;
|
|
BYTE* tmpOutBuffer;
|
|
const BYTE* dict;
|
|
size_t dictSize;
|
|
BYTE* tmpOut;
|
|
size_t tmpOutSize;
|
|
size_t tmpOutStart;
|
|
XXH32_state_t xxh;
|
|
XXH32_state_t blockChecksum;
|
|
BYTE header[LZ4F_HEADER_SIZE_MAX];
|
|
}; /* typedef'd to LZ4F_dctx in lz4frame.h */
|
|
|
|
|
|
/*! LZ4F_createDecompressionContext() :
|
|
* Create a decompressionContext object, which will track all decompression operations.
|
|
* Provides a pointer to a fully allocated and initialized LZ4F_decompressionContext object.
|
|
* Object can later be released using LZ4F_freeDecompressionContext().
|
|
* @return : if != 0, there was an error during context creation.
|
|
*/
|
|
LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_dctx** LZ4F_decompressionContextPtr, unsigned versionNumber)
|
|
{
|
|
LZ4F_dctx* const dctx = (LZ4F_dctx*)ALLOC_AND_ZERO(sizeof(LZ4F_dctx));
|
|
if (dctx == NULL) { /* failed allocation */
|
|
*LZ4F_decompressionContextPtr = NULL;
|
|
return err0r(LZ4F_ERROR_allocation_failed);
|
|
}
|
|
|
|
dctx->version = versionNumber;
|
|
*LZ4F_decompressionContextPtr = dctx;
|
|
return LZ4F_OK_NoError;
|
|
}
|
|
|
|
LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx)
|
|
{
|
|
LZ4F_errorCode_t result = LZ4F_OK_NoError;
|
|
if (dctx != NULL) { /* can accept NULL input, like free() */
|
|
result = (LZ4F_errorCode_t)dctx->dStage;
|
|
FREEMEM(dctx->tmpIn);
|
|
FREEMEM(dctx->tmpOutBuffer);
|
|
FREEMEM(dctx);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
|
|
/*==--- Streaming Decompression operations ---==*/
|
|
|
|
void LZ4F_resetDecompressionContext(LZ4F_dctx* dctx)
|
|
{
|
|
dctx->dStage = dstage_getFrameHeader;
|
|
dctx->dict = NULL;
|
|
dctx->dictSize = 0;
|
|
}
|
|
|
|
|
|
/*! LZ4F_decodeHeader() :
|
|
* input : `src` points at the **beginning of the frame**
|
|
* output : set internal values of dctx, such as
|
|
* dctx->frameInfo and dctx->dStage.
|
|
* Also allocates internal buffers.
|
|
* @return : nb Bytes read from src (necessarily <= srcSize)
|
|
* or an error code (testable with LZ4F_isError())
|
|
*/
|
|
static size_t LZ4F_decodeHeader(LZ4F_dctx* dctx, const void* src, size_t srcSize)
|
|
{
|
|
unsigned blockMode, blockChecksumFlag, contentSizeFlag, contentChecksumFlag, dictIDFlag, blockSizeID;
|
|
size_t frameHeaderSize;
|
|
const BYTE* srcPtr = (const BYTE*)src;
|
|
|
|
DEBUGLOG(5, "LZ4F_decodeHeader");
|
|
/* need to decode header to get frameInfo */
|
|
if (srcSize < minFHSize) return err0r(LZ4F_ERROR_frameHeader_incomplete); /* minimal frame header size */
|
|
MEM_INIT(&(dctx->frameInfo), 0, sizeof(dctx->frameInfo));
|
|
|
|
/* special case : skippable frames */
|
|
if ((LZ4F_readLE32(srcPtr) & 0xFFFFFFF0U) == LZ4F_MAGIC_SKIPPABLE_START) {
|
|
dctx->frameInfo.frameType = LZ4F_skippableFrame;
|
|
if (src == (void*)(dctx->header)) {
|
|
dctx->tmpInSize = srcSize;
|
|
dctx->tmpInTarget = 8;
|
|
dctx->dStage = dstage_storeSFrameSize;
|
|
return srcSize;
|
|
} else {
|
|
dctx->dStage = dstage_getSFrameSize;
|
|
return 4;
|
|
}
|
|
}
|
|
|
|
/* control magic number */
|
|
#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
|
|
if (LZ4F_readLE32(srcPtr) != LZ4F_MAGICNUMBER) {
|
|
DEBUGLOG(4, "frame header error : unknown magic number");
|
|
return err0r(LZ4F_ERROR_frameType_unknown);
|
|
}
|
|
#endif
|
|
dctx->frameInfo.frameType = LZ4F_frame;
|
|
|
|
/* Flags */
|
|
{ U32 const FLG = srcPtr[4];
|
|
U32 const version = (FLG>>6) & _2BITS;
|
|
blockChecksumFlag = (FLG>>4) & _1BIT;
|
|
blockMode = (FLG>>5) & _1BIT;
|
|
contentSizeFlag = (FLG>>3) & _1BIT;
|
|
contentChecksumFlag = (FLG>>2) & _1BIT;
|
|
dictIDFlag = FLG & _1BIT;
|
|
/* validate */
|
|
if (((FLG>>1)&_1BIT) != 0) return err0r(LZ4F_ERROR_reservedFlag_set); /* Reserved bit */
|
|
if (version != 1) return err0r(LZ4F_ERROR_headerVersion_wrong); /* Version Number, only supported value */
|
|
}
|
|
|
|
/* Frame Header Size */
|
|
frameHeaderSize = minFHSize + (contentSizeFlag?8:0) + (dictIDFlag?4:0);
|
|
|
|
if (srcSize < frameHeaderSize) {
|
|
/* not enough input to fully decode frame header */
|
|
if (srcPtr != dctx->header)
|
|
memcpy(dctx->header, srcPtr, srcSize);
|
|
dctx->tmpInSize = srcSize;
|
|
dctx->tmpInTarget = frameHeaderSize;
|
|
dctx->dStage = dstage_storeFrameHeader;
|
|
return srcSize;
|
|
}
|
|
|
|
{ U32 const BD = srcPtr[5];
|
|
blockSizeID = (BD>>4) & _3BITS;
|
|
/* validate */
|
|
if (((BD>>7)&_1BIT) != 0) return err0r(LZ4F_ERROR_reservedFlag_set); /* Reserved bit */
|
|
if (blockSizeID < 4) return err0r(LZ4F_ERROR_maxBlockSize_invalid); /* 4-7 only supported values for the time being */
|
|
if (((BD>>0)&_4BITS) != 0) return err0r(LZ4F_ERROR_reservedFlag_set); /* Reserved bits */
|
|
}
|
|
|
|
/* check header */
|
|
assert(frameHeaderSize > 5);
|
|
#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
|
|
{ BYTE const HC = LZ4F_headerChecksum(srcPtr+4, frameHeaderSize-5);
|
|
if (HC != srcPtr[frameHeaderSize-1])
|
|
return err0r(LZ4F_ERROR_headerChecksum_invalid);
|
|
}
|
|
#endif
|
|
|
|
/* save */
|
|
dctx->frameInfo.blockMode = (LZ4F_blockMode_t)blockMode;
|
|
dctx->frameInfo.blockChecksumFlag = (LZ4F_blockChecksum_t)blockChecksumFlag;
|
|
dctx->frameInfo.contentChecksumFlag = (LZ4F_contentChecksum_t)contentChecksumFlag;
|
|
dctx->frameInfo.blockSizeID = (LZ4F_blockSizeID_t)blockSizeID;
|
|
dctx->maxBlockSize = LZ4F_getBlockSize(blockSizeID);
|
|
if (contentSizeFlag)
|
|
dctx->frameRemainingSize =
|
|
dctx->frameInfo.contentSize = LZ4F_readLE64(srcPtr+6);
|
|
if (dictIDFlag)
|
|
dctx->frameInfo.dictID = LZ4F_readLE32(srcPtr + frameHeaderSize - 5);
|
|
|
|
dctx->dStage = dstage_init;
|
|
|
|
return frameHeaderSize;
|
|
}
|
|
|
|
|
|
/*! LZ4F_headerSize() :
|
|
* @return : size of frame header
|
|
* or an error code, which can be tested using LZ4F_isError()
|
|
*/
|
|
size_t LZ4F_headerSize(const void* src, size_t srcSize)
|
|
{
|
|
if (src == NULL) return err0r(LZ4F_ERROR_srcPtr_wrong);
|
|
|
|
/* minimal srcSize to determine header size */
|
|
if (srcSize < LZ4F_MIN_SIZE_TO_KNOW_HEADER_LENGTH)
|
|
return err0r(LZ4F_ERROR_frameHeader_incomplete);
|
|
|
|
/* special case : skippable frames */
|
|
if ((LZ4F_readLE32(src) & 0xFFFFFFF0U) == LZ4F_MAGIC_SKIPPABLE_START)
|
|
return 8;
|
|
|
|
/* control magic number */
|
|
#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
|
|
if (LZ4F_readLE32(src) != LZ4F_MAGICNUMBER)
|
|
return err0r(LZ4F_ERROR_frameType_unknown);
|
|
#endif
|
|
|
|
/* Frame Header Size */
|
|
{ BYTE const FLG = ((const BYTE*)src)[4];
|
|
U32 const contentSizeFlag = (FLG>>3) & _1BIT;
|
|
U32 const dictIDFlag = FLG & _1BIT;
|
|
return minFHSize + (contentSizeFlag?8:0) + (dictIDFlag?4:0);
|
|
}
|
|
}
|
|
|
|
/*! LZ4F_getFrameInfo() :
|
|
* This function extracts frame parameters (max blockSize, frame checksum, etc.).
|
|
* Usage is optional. Objective is to provide relevant information for allocation purposes.
|
|
* This function works in 2 situations :
|
|
* - At the beginning of a new frame, in which case it will decode this information from `srcBuffer`, and start the decoding process.
|
|
* Amount of input data provided must be large enough to successfully decode the frame header.
|
|
* A header size is variable, but is guaranteed to be <= LZ4F_HEADER_SIZE_MAX bytes. It's possible to provide more input data than this minimum.
|
|
* - After decoding has been started. In which case, no input is read, frame parameters are extracted from dctx.
|
|
* The number of bytes consumed from srcBuffer will be updated within *srcSizePtr (necessarily <= original value).
|
|
* Decompression must resume from (srcBuffer + *srcSizePtr).
|
|
* @return : an hint about how many srcSize bytes LZ4F_decompress() expects for next call,
|
|
* or an error code which can be tested using LZ4F_isError()
|
|
* note 1 : in case of error, dctx is not modified. Decoding operations can resume from where they stopped.
|
|
* note 2 : frame parameters are *copied into* an already allocated LZ4F_frameInfo_t structure.
|
|
*/
|
|
LZ4F_errorCode_t LZ4F_getFrameInfo(LZ4F_dctx* dctx,
|
|
LZ4F_frameInfo_t* frameInfoPtr,
|
|
const void* srcBuffer, size_t* srcSizePtr)
|
|
{
|
|
LZ4F_STATIC_ASSERT(dstage_getFrameHeader < dstage_storeFrameHeader);
|
|
if (dctx->dStage > dstage_storeFrameHeader) {
|
|
/* frameInfo already decoded */
|
|
size_t o=0, i=0;
|
|
*srcSizePtr = 0;
|
|
*frameInfoPtr = dctx->frameInfo;
|
|
/* returns : recommended nb of bytes for LZ4F_decompress() */
|
|
return LZ4F_decompress(dctx, NULL, &o, NULL, &i, NULL);
|
|
} else {
|
|
if (dctx->dStage == dstage_storeFrameHeader) {
|
|
/* frame decoding already started, in the middle of header => automatic fail */
|
|
*srcSizePtr = 0;
|
|
return err0r(LZ4F_ERROR_frameDecoding_alreadyStarted);
|
|
} else {
|
|
size_t const hSize = LZ4F_headerSize(srcBuffer, *srcSizePtr);
|
|
if (LZ4F_isError(hSize)) { *srcSizePtr=0; return hSize; }
|
|
if (*srcSizePtr < hSize) {
|
|
*srcSizePtr=0;
|
|
return err0r(LZ4F_ERROR_frameHeader_incomplete);
|
|
}
|
|
|
|
{ size_t decodeResult = LZ4F_decodeHeader(dctx, srcBuffer, hSize);
|
|
if (LZ4F_isError(decodeResult)) {
|
|
*srcSizePtr = 0;
|
|
} else {
|
|
*srcSizePtr = decodeResult;
|
|
decodeResult = BHSize; /* block header size */
|
|
}
|
|
*frameInfoPtr = dctx->frameInfo;
|
|
return decodeResult;
|
|
} } }
|
|
}
|
|
|
|
|
|
/* LZ4F_updateDict() :
|
|
* only used for LZ4F_blockLinked mode
|
|
* Condition : dstPtr != NULL
|
|
*/
|
|
static void LZ4F_updateDict(LZ4F_dctx* dctx,
|
|
const BYTE* dstPtr, size_t dstSize, const BYTE* dstBufferStart,
|
|
unsigned withinTmp)
|
|
{
|
|
assert(dstPtr != NULL);
|
|
if (dctx->dictSize==0) {
|
|
dctx->dict = (const BYTE*)dstPtr; /* priority to prefix mode */
|
|
}
|
|
assert(dctx->dict != NULL);
|
|
|
|
if (dctx->dict + dctx->dictSize == dstPtr) { /* prefix mode, everything within dstBuffer */
|
|
dctx->dictSize += dstSize;
|
|
return;
|
|
}
|
|
|
|
assert(dstPtr >= dstBufferStart);
|
|
if ((size_t)(dstPtr - dstBufferStart) + dstSize >= 64 KB) { /* history in dstBuffer becomes large enough to become dictionary */
|
|
dctx->dict = (const BYTE*)dstBufferStart;
|
|
dctx->dictSize = (size_t)(dstPtr - dstBufferStart) + dstSize;
|
|
return;
|
|
}
|
|
|
|
assert(dstSize < 64 KB); /* if dstSize >= 64 KB, dictionary would be set into dstBuffer directly */
|
|
|
|
/* dstBuffer does not contain whole useful history (64 KB), so it must be saved within tmpOutBuffer */
|
|
assert(dctx->tmpOutBuffer != NULL);
|
|
|
|
if (withinTmp && (dctx->dict == dctx->tmpOutBuffer)) { /* continue history within tmpOutBuffer */
|
|
/* withinTmp expectation : content of [dstPtr,dstSize] is same as [dict+dictSize,dstSize], so we just extend it */
|
|
assert(dctx->dict + dctx->dictSize == dctx->tmpOut + dctx->tmpOutStart);
|
|
dctx->dictSize += dstSize;
|
|
return;
|
|
}
|
|
|
|
if (withinTmp) { /* copy relevant dict portion in front of tmpOut within tmpOutBuffer */
|
|
size_t const preserveSize = (size_t)(dctx->tmpOut - dctx->tmpOutBuffer);
|
|
size_t copySize = 64 KB - dctx->tmpOutSize;
|
|
const BYTE* const oldDictEnd = dctx->dict + dctx->dictSize - dctx->tmpOutStart;
|
|
if (dctx->tmpOutSize > 64 KB) copySize = 0;
|
|
if (copySize > preserveSize) copySize = preserveSize;
|
|
|
|
memcpy(dctx->tmpOutBuffer + preserveSize - copySize, oldDictEnd - copySize, copySize);
|
|
|
|
dctx->dict = dctx->tmpOutBuffer;
|
|
dctx->dictSize = preserveSize + dctx->tmpOutStart + dstSize;
|
|
return;
|
|
}
|
|
|
|
if (dctx->dict == dctx->tmpOutBuffer) { /* copy dst into tmp to complete dict */
|
|
if (dctx->dictSize + dstSize > dctx->maxBufferSize) { /* tmp buffer not large enough */
|
|
size_t const preserveSize = 64 KB - dstSize;
|
|
memcpy(dctx->tmpOutBuffer, dctx->dict + dctx->dictSize - preserveSize, preserveSize);
|
|
dctx->dictSize = preserveSize;
|
|
}
|
|
memcpy(dctx->tmpOutBuffer + dctx->dictSize, dstPtr, dstSize);
|
|
dctx->dictSize += dstSize;
|
|
return;
|
|
}
|
|
|
|
/* join dict & dest into tmp */
|
|
{ size_t preserveSize = 64 KB - dstSize;
|
|
if (preserveSize > dctx->dictSize) preserveSize = dctx->dictSize;
|
|
memcpy(dctx->tmpOutBuffer, dctx->dict + dctx->dictSize - preserveSize, preserveSize);
|
|
memcpy(dctx->tmpOutBuffer + preserveSize, dstPtr, dstSize);
|
|
dctx->dict = dctx->tmpOutBuffer;
|
|
dctx->dictSize = preserveSize + dstSize;
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/*! LZ4F_decompress() :
|
|
* Call this function repetitively to regenerate compressed data in srcBuffer.
|
|
* The function will attempt to decode up to *srcSizePtr bytes from srcBuffer
|
|
* into dstBuffer of capacity *dstSizePtr.
|
|
*
|
|
* The number of bytes regenerated into dstBuffer will be provided within *dstSizePtr (necessarily <= original value).
|
|
*
|
|
* The number of bytes effectively read from srcBuffer will be provided within *srcSizePtr (necessarily <= original value).
|
|
* If number of bytes read is < number of bytes provided, then decompression operation is not complete.
|
|
* Remaining data will have to be presented again in a subsequent invocation.
|
|
*
|
|
* The function result is an hint of the better srcSize to use for next call to LZ4F_decompress.
|
|
* Schematically, it's the size of the current (or remaining) compressed block + header of next block.
|
|
* Respecting the hint provides a small boost to performance, since it allows less buffer shuffling.
|
|
* Note that this is just a hint, and it's always possible to any srcSize value.
|
|
* When a frame is fully decoded, @return will be 0.
|
|
* If decompression failed, @return is an error code which can be tested using LZ4F_isError().
|
|
*/
|
|
size_t LZ4F_decompress(LZ4F_dctx* dctx,
|
|
void* dstBuffer, size_t* dstSizePtr,
|
|
const void* srcBuffer, size_t* srcSizePtr,
|
|
const LZ4F_decompressOptions_t* decompressOptionsPtr)
|
|
{
|
|
LZ4F_decompressOptions_t optionsNull;
|
|
const BYTE* const srcStart = (const BYTE*)srcBuffer;
|
|
const BYTE* const srcEnd = srcStart + *srcSizePtr;
|
|
const BYTE* srcPtr = srcStart;
|
|
BYTE* const dstStart = (BYTE*)dstBuffer;
|
|
BYTE* const dstEnd = dstStart ? dstStart + *dstSizePtr : NULL;
|
|
BYTE* dstPtr = dstStart;
|
|
const BYTE* selectedIn = NULL;
|
|
unsigned doAnotherStage = 1;
|
|
size_t nextSrcSizeHint = 1;
|
|
|
|
|
|
DEBUGLOG(5, "LZ4F_decompress : %p,%u => %p,%u",
|
|
srcBuffer, (unsigned)*srcSizePtr, dstBuffer, (unsigned)*dstSizePtr);
|
|
if (dstBuffer == NULL) assert(*dstSizePtr == 0);
|
|
MEM_INIT(&optionsNull, 0, sizeof(optionsNull));
|
|
if (decompressOptionsPtr==NULL) decompressOptionsPtr = &optionsNull;
|
|
*srcSizePtr = 0;
|
|
*dstSizePtr = 0;
|
|
assert(dctx != NULL);
|
|
|
|
/* behaves as a state machine */
|
|
|
|
while (doAnotherStage) {
|
|
|
|
switch(dctx->dStage)
|
|
{
|
|
|
|
case dstage_getFrameHeader:
|
|
DEBUGLOG(6, "dstage_getFrameHeader");
|
|
if ((size_t)(srcEnd-srcPtr) >= maxFHSize) { /* enough to decode - shortcut */
|
|
size_t const hSize = LZ4F_decodeHeader(dctx, srcPtr, (size_t)(srcEnd-srcPtr)); /* will update dStage appropriately */
|
|
if (LZ4F_isError(hSize)) return hSize;
|
|
srcPtr += hSize;
|
|
break;
|
|
}
|
|
dctx->tmpInSize = 0;
|
|
if (srcEnd-srcPtr == 0) return minFHSize; /* 0-size input */
|
|
dctx->tmpInTarget = minFHSize; /* minimum size to decode header */
|
|
dctx->dStage = dstage_storeFrameHeader;
|
|
/* fall-through */
|
|
|
|
case dstage_storeFrameHeader:
|
|
DEBUGLOG(6, "dstage_storeFrameHeader");
|
|
{ size_t const sizeToCopy = MIN(dctx->tmpInTarget - dctx->tmpInSize, (size_t)(srcEnd - srcPtr));
|
|
memcpy(dctx->header + dctx->tmpInSize, srcPtr, sizeToCopy);
|
|
dctx->tmpInSize += sizeToCopy;
|
|
srcPtr += sizeToCopy;
|
|
}
|
|
if (dctx->tmpInSize < dctx->tmpInTarget) {
|
|
nextSrcSizeHint = (dctx->tmpInTarget - dctx->tmpInSize) + BHSize; /* rest of header + nextBlockHeader */
|
|
doAnotherStage = 0; /* not enough src data, ask for some more */
|
|
break;
|
|
}
|
|
{ size_t const hSize = LZ4F_decodeHeader(dctx, dctx->header, dctx->tmpInTarget); /* will update dStage appropriately */
|
|
if (LZ4F_isError(hSize)) return hSize;
|
|
}
|
|
break;
|
|
|
|
case dstage_init:
|
|
DEBUGLOG(6, "dstage_init");
|
|
if (dctx->frameInfo.contentChecksumFlag) (void)XXH32_reset(&(dctx->xxh), 0);
|
|
/* internal buffers allocation */
|
|
{ size_t const bufferNeeded = dctx->maxBlockSize
|
|
+ ((dctx->frameInfo.blockMode==LZ4F_blockLinked) ? 128 KB : 0);
|
|
if (bufferNeeded > dctx->maxBufferSize) { /* tmp buffers too small */
|
|
dctx->maxBufferSize = 0; /* ensure allocation will be re-attempted on next entry*/
|
|
FREEMEM(dctx->tmpIn);
|
|
dctx->tmpIn = (BYTE*)ALLOC(dctx->maxBlockSize + BFSize /* block checksum */);
|
|
if (dctx->tmpIn == NULL)
|
|
return err0r(LZ4F_ERROR_allocation_failed);
|
|
FREEMEM(dctx->tmpOutBuffer);
|
|
dctx->tmpOutBuffer= (BYTE*)ALLOC(bufferNeeded);
|
|
if (dctx->tmpOutBuffer== NULL)
|
|
return err0r(LZ4F_ERROR_allocation_failed);
|
|
dctx->maxBufferSize = bufferNeeded;
|
|
} }
|
|
dctx->tmpInSize = 0;
|
|
dctx->tmpInTarget = 0;
|
|
dctx->tmpOut = dctx->tmpOutBuffer;
|
|
dctx->tmpOutStart = 0;
|
|
dctx->tmpOutSize = 0;
|
|
|
|
dctx->dStage = dstage_getBlockHeader;
|
|
/* fall-through */
|
|
|
|
case dstage_getBlockHeader:
|
|
if ((size_t)(srcEnd - srcPtr) >= BHSize) {
|
|
selectedIn = srcPtr;
|
|
srcPtr += BHSize;
|
|
} else {
|
|
/* not enough input to read cBlockSize field */
|
|
dctx->tmpInSize = 0;
|
|
dctx->dStage = dstage_storeBlockHeader;
|
|
}
|
|
|
|
if (dctx->dStage == dstage_storeBlockHeader) /* can be skipped */
|
|
case dstage_storeBlockHeader:
|
|
{ size_t const remainingInput = (size_t)(srcEnd - srcPtr);
|
|
size_t const wantedData = BHSize - dctx->tmpInSize;
|
|
size_t const sizeToCopy = MIN(wantedData, remainingInput);
|
|
memcpy(dctx->tmpIn + dctx->tmpInSize, srcPtr, sizeToCopy);
|
|
srcPtr += sizeToCopy;
|
|
dctx->tmpInSize += sizeToCopy;
|
|
|
|
if (dctx->tmpInSize < BHSize) { /* not enough input for cBlockSize */
|
|
nextSrcSizeHint = BHSize - dctx->tmpInSize;
|
|
doAnotherStage = 0;
|
|
break;
|
|
}
|
|
selectedIn = dctx->tmpIn;
|
|
} /* if (dctx->dStage == dstage_storeBlockHeader) */
|
|
|
|
/* decode block header */
|
|
{ U32 const blockHeader = LZ4F_readLE32(selectedIn);
|
|
size_t const nextCBlockSize = blockHeader & 0x7FFFFFFFU;
|
|
size_t const crcSize = dctx->frameInfo.blockChecksumFlag * BFSize;
|
|
if (blockHeader==0) { /* frameEnd signal, no more block */
|
|
DEBUGLOG(5, "end of frame");
|
|
dctx->dStage = dstage_getSuffix;
|
|
break;
|
|
}
|
|
if (nextCBlockSize > dctx->maxBlockSize) {
|
|
return err0r(LZ4F_ERROR_maxBlockSize_invalid);
|
|
}
|
|
if (blockHeader & LZ4F_BLOCKUNCOMPRESSED_FLAG) {
|
|
/* next block is uncompressed */
|
|
dctx->tmpInTarget = nextCBlockSize;
|
|
DEBUGLOG(5, "next block is uncompressed (size %u)", (U32)nextCBlockSize);
|
|
if (dctx->frameInfo.blockChecksumFlag) {
|
|
(void)XXH32_reset(&dctx->blockChecksum, 0);
|
|
}
|
|
dctx->dStage = dstage_copyDirect;
|
|
break;
|
|
}
|
|
/* next block is a compressed block */
|
|
dctx->tmpInTarget = nextCBlockSize + crcSize;
|
|
dctx->dStage = dstage_getCBlock;
|
|
if (dstPtr==dstEnd || srcPtr==srcEnd) {
|
|
nextSrcSizeHint = BHSize + nextCBlockSize + crcSize;
|
|
doAnotherStage = 0;
|
|
}
|
|
break;
|
|
}
|
|
|
|
case dstage_copyDirect: /* uncompressed block */
|
|
DEBUGLOG(6, "dstage_copyDirect");
|
|
{ size_t sizeToCopy;
|
|
if (dstPtr == NULL) {
|
|
sizeToCopy = 0;
|
|
} else {
|
|
size_t const minBuffSize = MIN((size_t)(srcEnd-srcPtr), (size_t)(dstEnd-dstPtr));
|
|
sizeToCopy = MIN(dctx->tmpInTarget, minBuffSize);
|
|
memcpy(dstPtr, srcPtr, sizeToCopy);
|
|
if (dctx->frameInfo.blockChecksumFlag) {
|
|
(void)XXH32_update(&dctx->blockChecksum, srcPtr, sizeToCopy);
|
|
}
|
|
if (dctx->frameInfo.contentChecksumFlag)
|
|
(void)XXH32_update(&dctx->xxh, srcPtr, sizeToCopy);
|
|
if (dctx->frameInfo.contentSize)
|
|
dctx->frameRemainingSize -= sizeToCopy;
|
|
|
|
/* history management (linked blocks only)*/
|
|
if (dctx->frameInfo.blockMode == LZ4F_blockLinked) {
|
|
LZ4F_updateDict(dctx, dstPtr, sizeToCopy, dstStart, 0);
|
|
} }
|
|
|
|
srcPtr += sizeToCopy;
|
|
dstPtr += sizeToCopy;
|
|
if (sizeToCopy == dctx->tmpInTarget) { /* all done */
|
|
if (dctx->frameInfo.blockChecksumFlag) {
|
|
dctx->tmpInSize = 0;
|
|
dctx->dStage = dstage_getBlockChecksum;
|
|
} else
|
|
dctx->dStage = dstage_getBlockHeader; /* new block */
|
|
break;
|
|
}
|
|
dctx->tmpInTarget -= sizeToCopy; /* need to copy more */
|
|
}
|
|
nextSrcSizeHint = dctx->tmpInTarget +
|
|
+(dctx->frameInfo.blockChecksumFlag ? BFSize : 0)
|
|
+ BHSize /* next header size */;
|
|
doAnotherStage = 0;
|
|
break;
|
|
|
|
/* check block checksum for recently transferred uncompressed block */
|
|
case dstage_getBlockChecksum:
|
|
DEBUGLOG(6, "dstage_getBlockChecksum");
|
|
{ const void* crcSrc;
|
|
if ((srcEnd-srcPtr >= 4) && (dctx->tmpInSize==0)) {
|
|
crcSrc = srcPtr;
|
|
srcPtr += 4;
|
|
} else {
|
|
size_t const stillToCopy = 4 - dctx->tmpInSize;
|
|
size_t const sizeToCopy = MIN(stillToCopy, (size_t)(srcEnd-srcPtr));
|
|
memcpy(dctx->header + dctx->tmpInSize, srcPtr, sizeToCopy);
|
|
dctx->tmpInSize += sizeToCopy;
|
|
srcPtr += sizeToCopy;
|
|
if (dctx->tmpInSize < 4) { /* all input consumed */
|
|
doAnotherStage = 0;
|
|
break;
|
|
}
|
|
crcSrc = dctx->header;
|
|
}
|
|
{ U32 const readCRC = LZ4F_readLE32(crcSrc);
|
|
U32 const calcCRC = XXH32_digest(&dctx->blockChecksum);
|
|
#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
|
|
DEBUGLOG(6, "compare block checksum");
|
|
if (readCRC != calcCRC) {
|
|
DEBUGLOG(4, "incorrect block checksum: %08X != %08X",
|
|
readCRC, calcCRC);
|
|
return err0r(LZ4F_ERROR_blockChecksum_invalid);
|
|
}
|
|
#else
|
|
(void)readCRC;
|
|
(void)calcCRC;
|
|
#endif
|
|
} }
|
|
dctx->dStage = dstage_getBlockHeader; /* new block */
|
|
break;
|
|
|
|
case dstage_getCBlock:
|
|
DEBUGLOG(6, "dstage_getCBlock");
|
|
if ((size_t)(srcEnd-srcPtr) < dctx->tmpInTarget) {
|
|
dctx->tmpInSize = 0;
|
|
dctx->dStage = dstage_storeCBlock;
|
|
break;
|
|
}
|
|
/* input large enough to read full block directly */
|
|
selectedIn = srcPtr;
|
|
srcPtr += dctx->tmpInTarget;
|
|
|
|
if (0) /* always jump over next block */
|
|
case dstage_storeCBlock:
|
|
{ size_t const wantedData = dctx->tmpInTarget - dctx->tmpInSize;
|
|
size_t const inputLeft = (size_t)(srcEnd-srcPtr);
|
|
size_t const sizeToCopy = MIN(wantedData, inputLeft);
|
|
memcpy(dctx->tmpIn + dctx->tmpInSize, srcPtr, sizeToCopy);
|
|
dctx->tmpInSize += sizeToCopy;
|
|
srcPtr += sizeToCopy;
|
|
if (dctx->tmpInSize < dctx->tmpInTarget) { /* need more input */
|
|
nextSrcSizeHint = (dctx->tmpInTarget - dctx->tmpInSize)
|
|
+ (dctx->frameInfo.blockChecksumFlag ? BFSize : 0)
|
|
+ BHSize /* next header size */;
|
|
doAnotherStage = 0;
|
|
break;
|
|
}
|
|
selectedIn = dctx->tmpIn;
|
|
}
|
|
|
|
/* At this stage, input is large enough to decode a block */
|
|
if (dctx->frameInfo.blockChecksumFlag) {
|
|
dctx->tmpInTarget -= 4;
|
|
assert(selectedIn != NULL); /* selectedIn is defined at this stage (either srcPtr, or dctx->tmpIn) */
|
|
{ U32 const readBlockCrc = LZ4F_readLE32(selectedIn + dctx->tmpInTarget);
|
|
U32 const calcBlockCrc = XXH32(selectedIn, dctx->tmpInTarget, 0);
|
|
#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
|
|
if (readBlockCrc != calcBlockCrc)
|
|
return err0r(LZ4F_ERROR_blockChecksum_invalid);
|
|
#else
|
|
(void)readBlockCrc;
|
|
(void)calcBlockCrc;
|
|
#endif
|
|
} }
|
|
|
|
if ((size_t)(dstEnd-dstPtr) >= dctx->maxBlockSize) {
|
|
const char* dict = (const char*)dctx->dict;
|
|
size_t dictSize = dctx->dictSize;
|
|
int decodedSize;
|
|
assert(dstPtr != NULL);
|
|
if (dict && dictSize > 1 GB) {
|
|
/* the dictSize param is an int, avoid truncation / sign issues */
|
|
dict += dictSize - 64 KB;
|
|
dictSize = 64 KB;
|
|
}
|
|
/* enough capacity in `dst` to decompress directly there */
|
|
decodedSize = LZ4_decompress_safe_usingDict(
|
|
(const char*)selectedIn, (char*)dstPtr,
|
|
(int)dctx->tmpInTarget, (int)dctx->maxBlockSize,
|
|
dict, (int)dictSize);
|
|
if (decodedSize < 0) return err0r(LZ4F_ERROR_GENERIC); /* decompression failed */
|
|
if (dctx->frameInfo.contentChecksumFlag)
|
|
XXH32_update(&(dctx->xxh), dstPtr, (size_t)decodedSize);
|
|
if (dctx->frameInfo.contentSize)
|
|
dctx->frameRemainingSize -= (size_t)decodedSize;
|
|
|
|
/* dictionary management */
|
|
if (dctx->frameInfo.blockMode==LZ4F_blockLinked) {
|
|
LZ4F_updateDict(dctx, dstPtr, (size_t)decodedSize, dstStart, 0);
|
|
}
|
|
|
|
dstPtr += decodedSize;
|
|
dctx->dStage = dstage_getBlockHeader;
|
|
break;
|
|
}
|
|
|
|
/* not enough place into dst : decode into tmpOut */
|
|
/* ensure enough place for tmpOut */
|
|
if (dctx->frameInfo.blockMode == LZ4F_blockLinked) {
|
|
if (dctx->dict == dctx->tmpOutBuffer) {
|
|
if (dctx->dictSize > 128 KB) {
|
|
memcpy(dctx->tmpOutBuffer, dctx->dict + dctx->dictSize - 64 KB, 64 KB);
|
|
dctx->dictSize = 64 KB;
|
|
}
|
|
dctx->tmpOut = dctx->tmpOutBuffer + dctx->dictSize;
|
|
} else { /* dict not within tmp */
|
|
size_t const reservedDictSpace = MIN(dctx->dictSize, 64 KB);
|
|
dctx->tmpOut = dctx->tmpOutBuffer + reservedDictSpace;
|
|
} }
|
|
|
|
/* Decode block */
|
|
{ const char* dict = (const char*)dctx->dict;
|
|
size_t dictSize = dctx->dictSize;
|
|
int decodedSize;
|
|
if (dict && dictSize > 1 GB) {
|
|
/* the dictSize param is an int, avoid truncation / sign issues */
|
|
dict += dictSize - 64 KB;
|
|
dictSize = 64 KB;
|
|
}
|
|
decodedSize = LZ4_decompress_safe_usingDict(
|
|
(const char*)selectedIn, (char*)dctx->tmpOut,
|
|
(int)dctx->tmpInTarget, (int)dctx->maxBlockSize,
|
|
dict, (int)dictSize);
|
|
if (decodedSize < 0) /* decompression failed */
|
|
return err0r(LZ4F_ERROR_decompressionFailed);
|
|
if (dctx->frameInfo.contentChecksumFlag)
|
|
XXH32_update(&(dctx->xxh), dctx->tmpOut, (size_t)decodedSize);
|
|
if (dctx->frameInfo.contentSize)
|
|
dctx->frameRemainingSize -= (size_t)decodedSize;
|
|
dctx->tmpOutSize = (size_t)decodedSize;
|
|
dctx->tmpOutStart = 0;
|
|
dctx->dStage = dstage_flushOut;
|
|
}
|
|
/* fall-through */
|
|
|
|
case dstage_flushOut: /* flush decoded data from tmpOut to dstBuffer */
|
|
DEBUGLOG(6, "dstage_flushOut");
|
|
if (dstPtr != NULL) {
|
|
size_t const sizeToCopy = MIN(dctx->tmpOutSize - dctx->tmpOutStart, (size_t)(dstEnd-dstPtr));
|
|
memcpy(dstPtr, dctx->tmpOut + dctx->tmpOutStart, sizeToCopy);
|
|
|
|
/* dictionary management */
|
|
if (dctx->frameInfo.blockMode == LZ4F_blockLinked)
|
|
LZ4F_updateDict(dctx, dstPtr, sizeToCopy, dstStart, 1 /*withinTmp*/);
|
|
|
|
dctx->tmpOutStart += sizeToCopy;
|
|
dstPtr += sizeToCopy;
|
|
}
|
|
if (dctx->tmpOutStart == dctx->tmpOutSize) { /* all flushed */
|
|
dctx->dStage = dstage_getBlockHeader; /* get next block */
|
|
break;
|
|
}
|
|
/* could not flush everything : stop there, just request a block header */
|
|
doAnotherStage = 0;
|
|
nextSrcSizeHint = BHSize;
|
|
break;
|
|
|
|
case dstage_getSuffix:
|
|
if (dctx->frameRemainingSize)
|
|
return err0r(LZ4F_ERROR_frameSize_wrong); /* incorrect frame size decoded */
|
|
if (!dctx->frameInfo.contentChecksumFlag) { /* no checksum, frame is completed */
|
|
nextSrcSizeHint = 0;
|
|
LZ4F_resetDecompressionContext(dctx);
|
|
doAnotherStage = 0;
|
|
break;
|
|
}
|
|
if ((srcEnd - srcPtr) < 4) { /* not enough size for entire CRC */
|
|
dctx->tmpInSize = 0;
|
|
dctx->dStage = dstage_storeSuffix;
|
|
} else {
|
|
selectedIn = srcPtr;
|
|
srcPtr += 4;
|
|
}
|
|
|
|
if (dctx->dStage == dstage_storeSuffix) /* can be skipped */
|
|
case dstage_storeSuffix:
|
|
{ size_t const remainingInput = (size_t)(srcEnd - srcPtr);
|
|
size_t const wantedData = 4 - dctx->tmpInSize;
|
|
size_t const sizeToCopy = MIN(wantedData, remainingInput);
|
|
memcpy(dctx->tmpIn + dctx->tmpInSize, srcPtr, sizeToCopy);
|
|
srcPtr += sizeToCopy;
|
|
dctx->tmpInSize += sizeToCopy;
|
|
if (dctx->tmpInSize < 4) { /* not enough input to read complete suffix */
|
|
nextSrcSizeHint = 4 - dctx->tmpInSize;
|
|
doAnotherStage=0;
|
|
break;
|
|
}
|
|
selectedIn = dctx->tmpIn;
|
|
} /* if (dctx->dStage == dstage_storeSuffix) */
|
|
|
|
/* case dstage_checkSuffix: */ /* no direct entry, avoid initialization risks */
|
|
{ U32 const readCRC = LZ4F_readLE32(selectedIn);
|
|
U32 const resultCRC = XXH32_digest(&(dctx->xxh));
|
|
#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
|
|
if (readCRC != resultCRC)
|
|
return err0r(LZ4F_ERROR_contentChecksum_invalid);
|
|
#else
|
|
(void)readCRC;
|
|
(void)resultCRC;
|
|
#endif
|
|
nextSrcSizeHint = 0;
|
|
LZ4F_resetDecompressionContext(dctx);
|
|
doAnotherStage = 0;
|
|
break;
|
|
}
|
|
|
|
case dstage_getSFrameSize:
|
|
if ((srcEnd - srcPtr) >= 4) {
|
|
selectedIn = srcPtr;
|
|
srcPtr += 4;
|
|
} else {
|
|
/* not enough input to read cBlockSize field */
|
|
dctx->tmpInSize = 4;
|
|
dctx->tmpInTarget = 8;
|
|
dctx->dStage = dstage_storeSFrameSize;
|
|
}
|
|
|
|
if (dctx->dStage == dstage_storeSFrameSize)
|
|
case dstage_storeSFrameSize:
|
|
{ size_t const sizeToCopy = MIN(dctx->tmpInTarget - dctx->tmpInSize,
|
|
(size_t)(srcEnd - srcPtr) );
|
|
memcpy(dctx->header + dctx->tmpInSize, srcPtr, sizeToCopy);
|
|
srcPtr += sizeToCopy;
|
|
dctx->tmpInSize += sizeToCopy;
|
|
if (dctx->tmpInSize < dctx->tmpInTarget) {
|
|
/* not enough input to get full sBlockSize; wait for more */
|
|
nextSrcSizeHint = dctx->tmpInTarget - dctx->tmpInSize;
|
|
doAnotherStage = 0;
|
|
break;
|
|
}
|
|
selectedIn = dctx->header + 4;
|
|
} /* if (dctx->dStage == dstage_storeSFrameSize) */
|
|
|
|
/* case dstage_decodeSFrameSize: */ /* no direct entry */
|
|
{ size_t const SFrameSize = LZ4F_readLE32(selectedIn);
|
|
dctx->frameInfo.contentSize = SFrameSize;
|
|
dctx->tmpInTarget = SFrameSize;
|
|
dctx->dStage = dstage_skipSkippable;
|
|
break;
|
|
}
|
|
|
|
case dstage_skipSkippable:
|
|
{ size_t const skipSize = MIN(dctx->tmpInTarget, (size_t)(srcEnd-srcPtr));
|
|
srcPtr += skipSize;
|
|
dctx->tmpInTarget -= skipSize;
|
|
doAnotherStage = 0;
|
|
nextSrcSizeHint = dctx->tmpInTarget;
|
|
if (nextSrcSizeHint) break; /* still more to skip */
|
|
/* frame fully skipped : prepare context for a new frame */
|
|
LZ4F_resetDecompressionContext(dctx);
|
|
break;
|
|
}
|
|
} /* switch (dctx->dStage) */
|
|
} /* while (doAnotherStage) */
|
|
|
|
/* preserve history within tmp whenever necessary */
|
|
LZ4F_STATIC_ASSERT((unsigned)dstage_init == 2);
|
|
if ( (dctx->frameInfo.blockMode==LZ4F_blockLinked) /* next block will use up to 64KB from previous ones */
|
|
&& (dctx->dict != dctx->tmpOutBuffer) /* dictionary is not already within tmp */
|
|
&& (dctx->dict != NULL) /* dictionary exists */
|
|
&& (!decompressOptionsPtr->stableDst) /* cannot rely on dst data to remain there for next call */
|
|
&& ((unsigned)(dctx->dStage)-2 < (unsigned)(dstage_getSuffix)-2) ) /* valid stages : [init ... getSuffix[ */
|
|
{
|
|
if (dctx->dStage == dstage_flushOut) {
|
|
size_t const preserveSize = (size_t)(dctx->tmpOut - dctx->tmpOutBuffer);
|
|
size_t copySize = 64 KB - dctx->tmpOutSize;
|
|
const BYTE* oldDictEnd = dctx->dict + dctx->dictSize - dctx->tmpOutStart;
|
|
if (dctx->tmpOutSize > 64 KB) copySize = 0;
|
|
if (copySize > preserveSize) copySize = preserveSize;
|
|
assert(dctx->tmpOutBuffer != NULL);
|
|
|
|
memcpy(dctx->tmpOutBuffer + preserveSize - copySize, oldDictEnd - copySize, copySize);
|
|
|
|
dctx->dict = dctx->tmpOutBuffer;
|
|
dctx->dictSize = preserveSize + dctx->tmpOutStart;
|
|
} else {
|
|
const BYTE* const oldDictEnd = dctx->dict + dctx->dictSize;
|
|
size_t const newDictSize = MIN(dctx->dictSize, 64 KB);
|
|
|
|
memcpy(dctx->tmpOutBuffer, oldDictEnd - newDictSize, newDictSize);
|
|
|
|
dctx->dict = dctx->tmpOutBuffer;
|
|
dctx->dictSize = newDictSize;
|
|
dctx->tmpOut = dctx->tmpOutBuffer + newDictSize;
|
|
}
|
|
}
|
|
|
|
*srcSizePtr = (size_t)(srcPtr - srcStart);
|
|
*dstSizePtr = (size_t)(dstPtr - dstStart);
|
|
return nextSrcSizeHint;
|
|
}
|
|
|
|
/*! LZ4F_decompress_usingDict() :
|
|
* Same as LZ4F_decompress(), using a predefined dictionary.
|
|
* Dictionary is used "in place", without any preprocessing.
|
|
* It must remain accessible throughout the entire frame decoding.
|
|
*/
|
|
size_t LZ4F_decompress_usingDict(LZ4F_dctx* dctx,
|
|
void* dstBuffer, size_t* dstSizePtr,
|
|
const void* srcBuffer, size_t* srcSizePtr,
|
|
const void* dict, size_t dictSize,
|
|
const LZ4F_decompressOptions_t* decompressOptionsPtr)
|
|
{
|
|
if (dctx->dStage <= dstage_init) {
|
|
dctx->dict = (const BYTE*)dict;
|
|
dctx->dictSize = dictSize;
|
|
}
|
|
return LZ4F_decompress(dctx, dstBuffer, dstSizePtr,
|
|
srcBuffer, srcSizePtr,
|
|
decompressOptionsPtr);
|
|
}
|