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2398 lines
99 KiB
C
2398 lines
99 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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* ACCELERATION_DEFAULT :
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* Select "acceleration" for LZ4_compress_fast() when parameter value <= 0
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*/
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#define ACCELERATION_DEFAULT 1
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/*-************************************
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* CPU Feature Detection
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**************************************/
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/* LZ4_FORCE_MEMORY_ACCESS
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* By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
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* Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
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* The below switch allow to select different access method for improved performance.
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* Method 0 (default) : use `memcpy()`. Safe and portable.
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* Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
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* This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
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* Method 2 : direct access. This method is portable but violate C standard.
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* It can generate buggy code on targets which assembly generation depends on alignment.
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* But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
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* See https://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
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* Prefer these methods in priority order (0 > 1 > 2)
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*/
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#ifndef LZ4_FORCE_MEMORY_ACCESS /* can be defined externally */
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# if defined(__GNUC__) && \
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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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# 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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#ifdef _MSC_VER /* Visual Studio */
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# include <intrin.h>
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# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
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# pragma warning(disable : 4293) /* disable: C4293: too large shift (32-bits) */
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#endif /* _MSC_VER */
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#ifndef LZ4_FORCE_INLINE
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# ifdef _MSC_VER /* Visual Studio */
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# define LZ4_FORCE_INLINE static __forceinline
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# else
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# if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */
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# ifdef __GNUC__
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# define LZ4_FORCE_INLINE static inline __attribute__((always_inline))
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# else
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# define LZ4_FORCE_INLINE static inline
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# endif
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# else
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# define LZ4_FORCE_INLINE static
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# endif /* __STDC_VERSION__ */
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# endif /* _MSC_VER */
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#endif /* LZ4_FORCE_INLINE */
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/* LZ4_FORCE_O2_GCC_PPC64LE and LZ4_FORCE_O2_INLINE_GCC_PPC64LE
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* gcc on ppc64le generates an unrolled SIMDized loop for LZ4_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_GCC_PPC64LE __attribute__((optimize("O2")))
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# define LZ4_FORCE_O2_INLINE_GCC_PPC64LE __attribute__((optimize("O2"))) LZ4_FORCE_INLINE
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#else
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# define LZ4_FORCE_O2_GCC_PPC64LE
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# define LZ4_FORCE_O2_INLINE_GCC_PPC64LE static
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#endif
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#if (defined(__GNUC__) && (__GNUC__ >= 3)) || (defined(__INTEL_COMPILER) && (__INTEL_COMPILER >= 800)) || defined(__clang__)
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# define expect(expr,value) (__builtin_expect ((expr),(value)) )
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#else
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# define expect(expr,value) (expr)
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#endif
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#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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/*-************************************
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* Memory routines
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**************************************/
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#include <stdlib.h> /* malloc, calloc, free */
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#define ALLOC(s) malloc(s)
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#define ALLOC_AND_ZERO(s) calloc(1,s)
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#define FREEMEM(p) free(p)
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#include <string.h> /* memset, memcpy */
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#define MEM_INIT(p,v,s) memset((p),(v),(s))
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/*-************************************
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* 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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/*-************************************
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* Types
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**************************************/
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#if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
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# include <stdint.h>
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typedef uint8_t BYTE;
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typedef uint16_t U16;
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typedef uint32_t U32;
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typedef int32_t S32;
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typedef uint64_t U64;
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typedef uintptr_t uptrval;
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#else
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typedef unsigned char BYTE;
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typedef unsigned short U16;
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typedef unsigned int U32;
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typedef signed int S32;
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typedef unsigned long long U64;
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typedef size_t uptrval; /* generally true, except OpenVMS-64 */
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#endif
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#if defined(__x86_64__)
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typedef U64 reg_t; /* 64-bits in x32 mode */
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#else
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typedef size_t reg_t; /* 32-bits in x32 mode */
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#endif
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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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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; memcpy(&val, memPtr, sizeof(val)); return val;
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}
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static U32 LZ4_read32(const void* memPtr)
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{
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U32 val; memcpy(&val, memPtr, sizeof(val)); return val;
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}
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static reg_t LZ4_read_ARCH(const void* memPtr)
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{
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reg_t val; memcpy(&val, memPtr, sizeof(val)); return val;
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}
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static void LZ4_write16(void* memPtr, U16 value)
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{
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memcpy(memPtr, &value, sizeof(value));
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}
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static void LZ4_write32(void* memPtr, U32 value)
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{
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memcpy(memPtr, &value, sizeof(value));
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}
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#endif /* LZ4_FORCE_MEMORY_ACCESS */
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static U16 LZ4_readLE16(const void* memPtr)
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{
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if (LZ4_isLittleEndian()) {
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return LZ4_read16(memPtr);
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} else {
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const BYTE* p = (const BYTE*)memPtr;
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return (U16)((U16)p[0] + (p[1]<<8));
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}
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}
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static void LZ4_writeLE16(void* memPtr, U16 value)
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{
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if (LZ4_isLittleEndian()) {
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LZ4_write16(memPtr, value);
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} else {
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BYTE* p = (BYTE*)memPtr;
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p[0] = (BYTE) value;
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p[1] = (BYTE)(value>>8);
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}
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}
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/* customized variant of memcpy, which can overwrite up to 8 bytes beyond dstEnd */
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LZ4_FORCE_O2_INLINE_GCC_PPC64LE
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void LZ4_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 { 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(__x86_64__)
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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 and clang, it reduces performance. For more 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_O2_INLINE_GCC_PPC64LE 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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if (offset < 8) {
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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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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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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)
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* because it must be compatible with offsets >= 16. */
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LZ4_FORCE_O2_INLINE_GCC_PPC64LE void
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LZ4_wildCopy32(void* dstPtr, const void* srcPtr, void* dstEnd)
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{
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BYTE* d = (BYTE*)dstPtr;
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const BYTE* s = (const BYTE*)srcPtr;
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BYTE* const e = (BYTE*)dstEnd;
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do { memcpy(d,s,16); memcpy(d+16,s+16,16); d+=32; s+=32; } while (d<e);
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}
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/* LZ4_memcpy_using_offset() presumes :
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* - dstEnd >= dstPtr + MINMATCH
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* - there is at least 8 bytes available to write after dstEnd */
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LZ4_FORCE_O2_INLINE_GCC_PPC64LE void
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LZ4_memcpy_using_offset(BYTE* dstPtr, const BYTE* srcPtr, BYTE* dstEnd, const size_t offset)
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{
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BYTE v[8];
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assert(dstEnd >= dstPtr + MINMATCH);
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LZ4_write32(dstPtr, 0); /* silence an msan warning when offset==0 */
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switch(offset) {
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case 1:
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memset(v, *srcPtr, 8);
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break;
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case 2:
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memcpy(v, srcPtr, 2);
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memcpy(&v[2], srcPtr, 2);
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memcpy(&v[4], &v[0], 4);
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break;
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case 4:
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memcpy(v, srcPtr, 4);
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memcpy(&v[4], srcPtr, 4);
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break;
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default:
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LZ4_memcpy_using_offset_base(dstPtr, srcPtr, dstEnd, offset);
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return;
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}
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memcpy(dstPtr, v, 8);
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dstPtr += 8;
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while (dstPtr < dstEnd) {
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memcpy(dstPtr, v, 8);
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dstPtr += 8;
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}
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}
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#endif
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/*-************************************
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* Common functions
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**************************************/
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static unsigned LZ4_NbCommonBytes (reg_t val)
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{
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if (LZ4_isLittleEndian()) {
|
|
if (sizeof(val)==8) {
|
|
# if defined(_MSC_VER) && defined(_WIN64) && !defined(LZ4_FORCE_SW_BITCOUNT)
|
|
unsigned long r = 0;
|
|
_BitScanForward64( &r, (U64)val );
|
|
return (int)(r>>3);
|
|
# elif (defined(__clang__) || (defined(__GNUC__) && (__GNUC__>=3))) && !defined(LZ4_FORCE_SW_BITCOUNT)
|
|
return (unsigned)__builtin_ctzll((U64)val) >> 3;
|
|
# else
|
|
static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2,
|
|
0, 3, 1, 3, 1, 4, 2, 7,
|
|
0, 2, 3, 6, 1, 5, 3, 5,
|
|
1, 3, 4, 4, 2, 5, 6, 7,
|
|
7, 0, 1, 2, 3, 3, 4, 6,
|
|
2, 6, 5, 5, 3, 4, 5, 6,
|
|
7, 1, 2, 4, 6, 4, 4, 5,
|
|
7, 2, 6, 5, 7, 6, 7, 7 };
|
|
return DeBruijnBytePos[((U64)((val & -(long long)val) * 0x0218A392CDABBD3FULL)) >> 58];
|
|
# endif
|
|
} else /* 32 bits */ {
|
|
# if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
|
|
unsigned long r;
|
|
_BitScanForward( &r, (U32)val );
|
|
return (int)(r>>3);
|
|
# elif (defined(__clang__) || (defined(__GNUC__) && (__GNUC__>=3))) && !defined(LZ4_FORCE_SW_BITCOUNT)
|
|
return (unsigned)__builtin_ctz((U32)val) >> 3;
|
|
# else
|
|
static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0,
|
|
3, 2, 2, 1, 3, 2, 0, 1,
|
|
3, 3, 1, 2, 2, 2, 2, 0,
|
|
3, 1, 2, 0, 1, 0, 1, 1 };
|
|
return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27];
|
|
# endif
|
|
}
|
|
} else /* Big Endian CPU */ {
|
|
if (sizeof(val)==8) { /* 64-bits */
|
|
# if defined(_MSC_VER) && defined(_WIN64) && !defined(LZ4_FORCE_SW_BITCOUNT)
|
|
unsigned long r = 0;
|
|
_BitScanReverse64( &r, val );
|
|
return (unsigned)(r>>3);
|
|
# elif (defined(__clang__) || (defined(__GNUC__) && (__GNUC__>=3))) && !defined(LZ4_FORCE_SW_BITCOUNT)
|
|
return (unsigned)__builtin_clzll((U64)val) >> 3;
|
|
# else
|
|
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
|
|
} else /* 32 bits */ {
|
|
# if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
|
|
unsigned long r = 0;
|
|
_BitScanReverse( &r, (unsigned long)val );
|
|
return (unsigned)(r>>3);
|
|
# elif (defined(__clang__) || (defined(__GNUC__) && (__GNUC__>=3))) && !defined(LZ4_FORCE_SW_BITCOUNT)
|
|
return (unsigned)__builtin_clz((U32)val) >> 3;
|
|
# else
|
|
unsigned r;
|
|
if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
|
|
r += (!val);
|
|
return r;
|
|
# endif
|
|
}
|
|
}
|
|
}
|
|
|
|
#define STEPSIZE sizeof(reg_t)
|
|
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() { 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
|
|
********************************/
|
|
static U32 LZ4_hash4(U32 sequence, tableType_t const tableType)
|
|
{
|
|
if (tableType == byU16)
|
|
return ((sequence * 2654435761U) >> ((MINMATCH*8)-(LZ4_HASHLOG+1)));
|
|
else
|
|
return ((sequence * 2654435761U) >> ((MINMATCH*8)-LZ4_HASHLOG));
|
|
}
|
|
|
|
static U32 LZ4_hash5(U64 sequence, tableType_t const tableType)
|
|
{
|
|
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);
|
|
}
|
|
|
|
static 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; }
|
|
}
|
|
}
|
|
|
|
static void LZ4_putIndexOnHash(U32 idx, U32 h, void* tableBase, tableType_t const tableType)
|
|
{
|
|
switch (tableType)
|
|
{
|
|
default: /* fallthrough */
|
|
case clearedTable: /* fallthrough */
|
|
case byPtr: { /* illegal! */ assert(0); return; }
|
|
case byU32: { U32* hashTable = (U32*) tableBase; hashTable[h] = idx; return; }
|
|
case byU16: { U16* hashTable = (U16*) tableBase; assert(idx < 65536); hashTable[h] = (U16)idx; return; }
|
|
}
|
|
}
|
|
|
|
static void LZ4_putPositionOnHash(const BYTE* p, U32 h,
|
|
void* tableBase, tableType_t const tableType,
|
|
const BYTE* srcBase)
|
|
{
|
|
switch (tableType)
|
|
{
|
|
case clearedTable: { /* illegal! */ assert(0); return; }
|
|
case byPtr: { const BYTE** hashTable = (const BYTE**)tableBase; hashTable[h] = p; return; }
|
|
case byU32: { U32* hashTable = (U32*) tableBase; hashTable[h] = (U32)(p-srcBase); return; }
|
|
case byU16: { U16* hashTable = (U16*) tableBase; hashTable[h] = (U16)(p-srcBase); return; }
|
|
}
|
|
}
|
|
|
|
LZ4_FORCE_INLINE void LZ4_putPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
|
|
{
|
|
U32 const h = LZ4_hashPosition(p, tableType);
|
|
LZ4_putPositionOnHash(p, h, tableBase, tableType, srcBase);
|
|
}
|
|
|
|
/* LZ4_getIndexOnHash() :
|
|
* Index of match position registered in hash table.
|
|
* hash position must be calculated by using base+index, or dictBase+index.
|
|
* Assumption 1 : only valid if tableType == byU32 or byU16.
|
|
* Assumption 2 : h is presumed valid (within limits of hash table)
|
|
*/
|
|
static U32 LZ4_getIndexOnHash(U32 h, const void* tableBase, tableType_t tableType)
|
|
{
|
|
LZ4_STATIC_ASSERT(LZ4_MEMORY_USAGE > 2);
|
|
if (tableType == byU32) {
|
|
const U32* const hashTable = (const U32*) tableBase;
|
|
assert(h < (1U << (LZ4_MEMORY_USAGE-2)));
|
|
return hashTable[h];
|
|
}
|
|
if (tableType == byU16) {
|
|
const U16* const hashTable = (const U16*) tableBase;
|
|
assert(h < (1U << (LZ4_MEMORY_USAGE-1)));
|
|
return hashTable[h];
|
|
}
|
|
assert(0); return 0; /* forbidden case */
|
|
}
|
|
|
|
static const BYTE* LZ4_getPositionOnHash(U32 h, const void* tableBase, tableType_t tableType, const BYTE* srcBase)
|
|
{
|
|
if (tableType == byPtr) { const BYTE* const* hashTable = (const BYTE* const*) tableBase; return hashTable[h]; }
|
|
if (tableType == byU32) { const U32* const hashTable = (const U32*) tableBase; return hashTable[h] + srcBase; }
|
|
{ const U16* const hashTable = (const U16*) tableBase; return hashTable[h] + srcBase; } /* default, to ensure a return */
|
|
}
|
|
|
|
LZ4_FORCE_INLINE const BYTE*
|
|
LZ4_getPosition(const BYTE* p,
|
|
const void* tableBase, tableType_t tableType,
|
|
const BYTE* srcBase)
|
|
{
|
|
U32 const h = LZ4_hashPosition(p, tableType);
|
|
return LZ4_getPositionOnHash(h, tableBase, tableType, srcBase);
|
|
}
|
|
|
|
LZ4_FORCE_INLINE void
|
|
LZ4_prepareTable(LZ4_stream_t_internal* const cctx,
|
|
const int inputSize,
|
|
const tableType_t tableType) {
|
|
/* If compression failed during the previous step, then the context
|
|
* is marked as dirty, therefore, it has to be fully reset.
|
|
*/
|
|
if (cctx->dirty) {
|
|
DEBUGLOG(5, "LZ4_prepareTable: Full reset for %p", cctx);
|
|
MEM_INIT(cctx, 0, sizeof(LZ4_stream_t_internal));
|
|
return;
|
|
}
|
|
|
|
/* If the table hasn't been used, it's guaranteed to be zeroed out, and is
|
|
* therefore safe to use no matter what mode we're in. Otherwise, we figure
|
|
* out if it's safe to leave as is or whether it needs to be reset.
|
|
*/
|
|
if (cctx->tableType != clearedTable) {
|
|
assert(inputSize >= 0);
|
|
if (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 = 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 */
|
|
LZ4_FORCE_INLINE int LZ4_compress_generic(
|
|
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 + dictSize;
|
|
const BYTE* anchor = (const BYTE*) source;
|
|
const BYTE* const iend = ip + inputSize;
|
|
const BYTE* const mflimitPlusOne = iend - MFLIMIT + 1;
|
|
const BYTE* const matchlimit = iend - LASTLITERALS;
|
|
|
|
/* the dictCtx currentOffset is indexed on the start of the dictionary,
|
|
* while a dictionary in the current context precedes the currentOffset */
|
|
const BYTE* dictBase = (dictDirective == usingDictCtx) ?
|
|
dictionary + dictSize - dictCtx->currentOffset :
|
|
dictionary + dictSize - startIndex;
|
|
|
|
BYTE* op = (BYTE*) dest;
|
|
BYTE* const olimit = op + maxOutputSize;
|
|
|
|
U32 offset = 0;
|
|
U32 forwardH;
|
|
|
|
DEBUGLOG(5, "LZ4_compress_generic: srcSize=%i, tableType=%u", inputSize, tableType);
|
|
/* If init conditions are not met, we don't have to mark stream
|
|
* as having dirty context, since no action was taken yet */
|
|
if (outputDirective == fillOutput && maxOutputSize < 1) { return 0; } /* Impossible to store anything */
|
|
if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) { return 0; } /* Unsupported inputSize, too large (or negative) */
|
|
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 = (U16)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;
|
|
lastRun -= (lastRun+240)/255;
|
|
} else {
|
|
assert(outputDirective == limitedOutput);
|
|
return 0; /* cannot compress within `dst` budget. Stored indexes in hash table are nonetheless fine */
|
|
}
|
|
}
|
|
if (lastRun >= RUN_MASK) {
|
|
size_t accumulator = lastRun - RUN_MASK;
|
|
*op++ = RUN_MASK << ML_BITS;
|
|
for(; accumulator >= 255 ; accumulator-=255) *op++ = 255;
|
|
*op++ = (BYTE) accumulator;
|
|
} else {
|
|
*op++ = (BYTE)(lastRun<<ML_BITS);
|
|
}
|
|
memcpy(op, anchor, lastRun);
|
|
ip = anchor + lastRun;
|
|
op += lastRun;
|
|
}
|
|
|
|
if (outputDirective == fillOutput) {
|
|
*inputConsumed = (int) (((const char*)ip)-source);
|
|
}
|
|
DEBUGLOG(5, "LZ4_compress_generic: compressed %i bytes into %i bytes", inputSize, (int)(((char*)op) - dest));
|
|
result = (int)(((char*)op) - dest);
|
|
assert(result > 0);
|
|
return result;
|
|
}
|
|
|
|
|
|
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 = ACCELERATION_DEFAULT;
|
|
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 = ACCELERATION_DEFAULT;
|
|
|
|
if (dstCapacity >= LZ4_compressBound(srcSize)) {
|
|
if (srcSize < LZ4_64Klimit) {
|
|
const tableType_t tableType = byU16;
|
|
LZ4_prepareTable(ctx, srcSize, tableType);
|
|
if (ctx->currentOffset) {
|
|
return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 0, notLimited, tableType, noDict, dictSmall, acceleration);
|
|
} else {
|
|
return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 0, notLimited, tableType, noDict, noDictIssue, acceleration);
|
|
}
|
|
} else {
|
|
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);
|
|
}
|
|
|
|
|
|
/* hidden debug function */
|
|
/* strangely enough, gcc generates faster code when this function is uncommented, even if unused */
|
|
int LZ4_compress_fast_force(const char* src, char* dst, int srcSize, int dstCapacity, int acceleration)
|
|
{
|
|
LZ4_stream_t ctx;
|
|
LZ4_initStream(&ctx, sizeof(ctx));
|
|
|
|
if (srcSize < LZ4_64Klimit) {
|
|
return LZ4_compress_generic(&ctx.internal_donotuse, src, dst, srcSize, NULL, dstCapacity, limitedOutput, byU16, noDict, noDictIssue, acceleration);
|
|
} else {
|
|
tableType_t const addrMode = (sizeof(void*) > 4) ? byU32 : byPtr;
|
|
return LZ4_compress_generic(&ctx.internal_donotuse, src, dst, srcSize, NULL, dstCapacity, limitedOutput, addrMode, noDict, noDictIssue, acceleration);
|
|
}
|
|
}
|
|
|
|
|
|
/* 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;
|
|
}
|
|
|
|
#ifndef _MSC_VER /* for some reason, Visual fails the aligment test on 32-bit x86 :
|
|
it reports an aligment of 8-bytes,
|
|
while actually aligning LZ4_stream_t on 4 bytes. */
|
|
static size_t LZ4_stream_t_alignment(void)
|
|
{
|
|
struct { char c; LZ4_stream_t t; } t_a;
|
|
return sizeof(t_a) - sizeof(t_a.t);
|
|
}
|
|
#endif
|
|
|
|
LZ4_stream_t* LZ4_initStream (void* buffer, size_t size)
|
|
{
|
|
DEBUGLOG(5, "LZ4_initStream");
|
|
if (buffer == NULL) { return NULL; }
|
|
if (size < sizeof(LZ4_stream_t)) { return NULL; }
|
|
#ifndef _MSC_VER /* for some reason, Visual fails the aligment test on 32-bit x86 :
|
|
it reports an aligment of 8-bytes,
|
|
while actually aligning LZ4_stream_t on 4 bytes. */
|
|
if (((size_t)buffer) & (LZ4_stream_t_alignment() - 1)) { return NULL; } /* alignment check */
|
|
#endif
|
|
MEM_INIT(buffer, 0, sizeof(LZ4_stream_t));
|
|
return (LZ4_stream_t*)buffer;
|
|
}
|
|
|
|
/* resetStream is now deprecated,
|
|
* prefer initStream() which is more general */
|
|
void LZ4_resetStream (LZ4_stream_t* LZ4_stream)
|
|
{
|
|
DEBUGLOG(5, "LZ4_resetStream (ctx:%p)", LZ4_stream);
|
|
MEM_INIT(LZ4_stream, 0, sizeof(LZ4_stream_t));
|
|
}
|
|
|
|
void LZ4_resetStream_fast(LZ4_stream_t* ctx) {
|
|
LZ4_prepareTable(&(ctx->internal_donotuse), 0, byU32);
|
|
}
|
|
|
|
int LZ4_freeStream (LZ4_stream_t* LZ4_stream)
|
|
{
|
|
if (!LZ4_stream) return 0; /* support free on NULL */
|
|
DEBUGLOG(5, "LZ4_freeStream %p", LZ4_stream);
|
|
FREEMEM(LZ4_stream);
|
|
return (0);
|
|
}
|
|
|
|
|
|
#define HASH_UNIT sizeof(reg_t)
|
|
int LZ4_loadDict (LZ4_stream_t* LZ4_dict, const char* dictionary, int dictSize)
|
|
{
|
|
LZ4_stream_t_internal* dict = &LZ4_dict->internal_donotuse;
|
|
const tableType_t tableType = byU32;
|
|
const BYTE* p = (const BYTE*)dictionary;
|
|
const BYTE* const dictEnd = p + dictSize;
|
|
const BYTE* base;
|
|
|
|
DEBUGLOG(4, "LZ4_loadDict (%i bytes from %p into %p)", dictSize, dictionary, LZ4_dict);
|
|
|
|
/* 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 = 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);
|
|
|
|
/* Calling LZ4_resetStream_fast() here makes sure that changes will not be
|
|
* erased by subsequent calls to LZ4_resetStream_fast() in case stream was
|
|
* marked as having dirty context, e.g. requiring full reset.
|
|
*/
|
|
LZ4_resetStream_fast(workingStream);
|
|
|
|
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);
|
|
|
|
if (streamPtr->dirty) { return 0; } /* Uninitialized structure detected */
|
|
LZ4_renormDictT(streamPtr, inputSize); /* avoid index overflow */
|
|
if (acceleration < 1) acceleration = ACCELERATION_DEFAULT;
|
|
|
|
/* 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.
|
|
*/
|
|
memcpy(streamPtr, streamPtr->dictCtx, sizeof(LZ4_stream_t));
|
|
result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingExtDict, noDictIssue, acceleration);
|
|
} else {
|
|
result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingDictCtx, noDictIssue, acceleration);
|
|
}
|
|
} else {
|
|
if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset)) {
|
|
result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingExtDict, dictSmall, acceleration);
|
|
} else {
|
|
result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingExtDict, noDictIssue, acceleration);
|
|
}
|
|
}
|
|
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; }
|
|
|
|
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)
|
|
{
|
|
unsigned length = 0;
|
|
unsigned s;
|
|
if (initial_check && unlikely((*ip) >= lencheck)) { /* overflow detection */
|
|
*error = initial_error;
|
|
return length;
|
|
}
|
|
do {
|
|
s = **ip;
|
|
(*ip)++;
|
|
length += s;
|
|
if (loop_check && unlikely((*ip) >= lencheck)) { /* overflow detection */
|
|
*error = loop_error;
|
|
return length;
|
|
}
|
|
} while (s==255);
|
|
|
|
return length;
|
|
}
|
|
|
|
/*! 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, endOnInput, endOnInput, &error);
|
|
if (error == initial_error) { goto _output_error; }
|
|
if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)(op))) { goto _output_error; } /* overflow detection */
|
|
if ((safeDecode) && unlikely((uptrval)(ip)+length<(uptrval)(ip))) { goto _output_error; } /* overflow detection */
|
|
|
|
/* copy literals */
|
|
cpy = op+length;
|
|
LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH);
|
|
if (endOnInput) { /* LZ4_decompress_safe() */
|
|
if ((cpy>oend-32) || (ip+length>iend-32)) { goto safe_literal_copy; }
|
|
LZ4_wildCopy32(op, ip, cpy);
|
|
} else { /* LZ4_decompress_fast() */
|
|
if (cpy>oend-8) { goto safe_literal_copy; }
|
|
LZ4_wildCopy8(op, ip, cpy); /* LZ4_decompress_fast() cannot copy more than 8 bytes at a time :
|
|
* it doesn't know input length, and only relies on end-of-block properties */
|
|
}
|
|
ip += length; op = cpy;
|
|
} else {
|
|
cpy = op+length;
|
|
if (endOnInput) { /* LZ4_decompress_safe() */
|
|
DEBUGLOG(7, "copy %u bytes in a 16-bytes stripe", (unsigned)length);
|
|
/* We don't need to check oend, since we check it once for each loop below */
|
|
if (ip > iend-(16 + 1/*max lit + offset + nextToken*/)) { goto safe_literal_copy; }
|
|
/* Literals can only be 14, but hope compilers optimize if we copy by a register size */
|
|
memcpy(op, ip, 16);
|
|
} else { /* LZ4_decompress_fast() */
|
|
/* LZ4_decompress_fast() cannot copy more than 8 bytes at a time :
|
|
* it doesn't know input length, and relies on end-of-block properties */
|
|
memcpy(op, ip, 8);
|
|
if (length > 8) { memcpy(op+8, ip+8, 8); }
|
|
}
|
|
ip += length; op = cpy;
|
|
}
|
|
|
|
/* get offset */
|
|
offset = LZ4_readLE16(ip); ip+=2;
|
|
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, 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);
|
|
|
|
memcpy(op, match, 8);
|
|
memcpy(op+8, match+8, 8);
|
|
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) {
|
|
length = MIN(length, (size_t)(oend-op)); /* reach end of buffer */
|
|
} 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;
|
|
memcpy(op, dictEnd - copySize, copySize);
|
|
op += copySize;
|
|
if (restSize > (size_t)(op - lowPrefix)) { /* overlap copy */
|
|
BYTE* const endOfMatch = op + restSize;
|
|
const BYTE* copyFrom = lowPrefix;
|
|
while (op < endOfMatch) { *op++ = *copyFrom++; }
|
|
} else {
|
|
memcpy(op, lowPrefix, restSize);
|
|
op += restSize;
|
|
} }
|
|
continue;
|
|
}
|
|
|
|
/* copy match within block */
|
|
cpy = op + length;
|
|
|
|
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 */
|
|
memcpy(op, ip, endOnInput ? 16 : 8);
|
|
op += length; ip += length;
|
|
|
|
/* The second stage: prepare for match copying, decode full info.
|
|
* If it doesn't work out, the info won't be wasted. */
|
|
length = token & ML_MASK; /* match length */
|
|
offset = LZ4_readLE16(ip); ip += 2;
|
|
match = op - offset;
|
|
assert(match <= op); /* check overflow */
|
|
|
|
/* Do not deal with overlapping matches. */
|
|
if ( (length != ML_MASK)
|
|
&& (offset >= 8)
|
|
&& (dict==withPrefix64k || match >= lowPrefix) ) {
|
|
/* Copy the match. */
|
|
memcpy(op + 0, match + 0, 8);
|
|
memcpy(op + 8, match + 8, 8);
|
|
memcpy(op +16, match +16, 2);
|
|
op += length + MINMATCH;
|
|
/* Both stages worked, load the next token. */
|
|
continue;
|
|
}
|
|
|
|
/* The second stage didn't work out, but the info is ready.
|
|
* Propel it right to the point of match copying. */
|
|
goto _copy_match;
|
|
}
|
|
|
|
/* decode literal length */
|
|
if (length == RUN_MASK) {
|
|
variable_length_error error = ok;
|
|
length += read_variable_length(&ip, iend-RUN_MASK, endOnInput, endOnInput, &error);
|
|
if (error == initial_error) { goto _output_error; }
|
|
if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)(op))) { goto _output_error; } /* overflow detection */
|
|
if ((safeDecode) && unlikely((uptrval)(ip)+length<(uptrval)(ip))) { goto _output_error; } /* overflow detection */
|
|
}
|
|
|
|
/* copy literals */
|
|
cpy = op+length;
|
|
#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.
|
|
* If we've hit the input parsing condition then this must be the last sequence.
|
|
* If we've hit the output parsing condition then we are either using partialDecoding
|
|
* or we've hit the output parsing condition.
|
|
*/
|
|
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);
|
|
/* If we're in this block because of the input parsing condition, then we must be on the
|
|
* last sequence (or invalid), so we must check that we exactly consume the input.
|
|
*/
|
|
if ((ip+length>iend-(2+1+LASTLITERALS)) && (ip+length != iend)) { goto _output_error; }
|
|
assert(ip+length <= iend);
|
|
/* We are finishing in the middle of a literals segment.
|
|
* Break after the copy.
|
|
*/
|
|
if (cpy > oend) {
|
|
cpy = oend;
|
|
assert(op<=oend);
|
|
length = (size_t)(oend-op);
|
|
}
|
|
assert(ip+length <= iend);
|
|
} 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))) { goto _output_error; }
|
|
}
|
|
memmove(op, ip, length); /* supports overlapping memory regions, which 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 hit
|
|
* the input parsing restriction.
|
|
*/
|
|
if (!partialDecoding || (cpy == oend) || (ip == iend)) {
|
|
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, 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;
|
|
memcpy(op, dictEnd - copySize, copySize);
|
|
op += copySize;
|
|
if (restSize > (size_t)(op - lowPrefix)) { /* overlap copy */
|
|
BYTE* const endOfMatch = op + restSize;
|
|
const BYTE* copyFrom = lowPrefix;
|
|
while (op < endOfMatch) *op++ = *copyFrom++;
|
|
} else {
|
|
memcpy(op, lowPrefix, restSize);
|
|
op += restSize;
|
|
} }
|
|
continue;
|
|
}
|
|
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 {
|
|
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];
|
|
memcpy(op+4, match, 4);
|
|
match -= dec64table[offset];
|
|
} else {
|
|
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 {
|
|
memcpy(op, match, 8);
|
|
if (length > 16) { LZ4_wildCopy8(op+8, match+8, cpy); }
|
|
}
|
|
op = cpy; /* wildcopy correction */
|
|
}
|
|
|
|
/* end of decoding */
|
|
if (endOnInput) {
|
|
return (int) (((char*)op)-dst); /* Nb of output bytes decoded */
|
|
} else {
|
|
return (int) (((const char*)ip)-src); /* Nb of input bytes read */
|
|
}
|
|
|
|
/* Overflow error detected */
|
|
_output_error:
|
|
return (int) (-(((const char*)ip)-src))-1;
|
|
}
|
|
}
|
|
|
|
|
|
/*===== Instantiate the API decoding functions. =====*/
|
|
|
|
LZ4_FORCE_O2_GCC_PPC64LE
|
|
int LZ4_decompress_safe(const char* source, char* dest, int compressedSize, int maxDecompressedSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxDecompressedSize,
|
|
endOnInputSize, decode_full_block, noDict,
|
|
(BYTE*)dest, NULL, 0);
|
|
}
|
|
|
|
LZ4_FORCE_O2_GCC_PPC64LE
|
|
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_GCC_PPC64LE
|
|
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_GCC_PPC64LE /* Exported, an obsolete API function. */
|
|
int LZ4_decompress_safe_withPrefix64k(const char* source, char* dest, int compressedSize, int maxOutputSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
|
|
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_GCC_PPC64LE
|
|
static int LZ4_decompress_safe_withSmallPrefix(const char* source, char* dest, int compressedSize, int maxOutputSize,
|
|
size_t prefixSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
|
|
endOnInputSize, decode_full_block, noDict,
|
|
(BYTE*)dest-prefixSize, NULL, 0);
|
|
}
|
|
|
|
LZ4_FORCE_O2_GCC_PPC64LE
|
|
int LZ4_decompress_safe_forceExtDict(const char* source, char* dest,
|
|
int compressedSize, int maxOutputSize,
|
|
const void* dictStart, size_t dictSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
|
|
endOnInputSize, decode_full_block, usingExtDict,
|
|
(BYTE*)dest, (const BYTE*)dictStart, dictSize);
|
|
}
|
|
|
|
LZ4_FORCE_O2_GCC_PPC64LE
|
|
static int LZ4_decompress_fast_extDict(const char* source, char* dest, int originalSize,
|
|
const void* dictStart, size_t dictSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, 0, originalSize,
|
|
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_GCC_PPC64LE
|
|
int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxOutputSize)
|
|
{
|
|
LZ4_streamDecode_t_internal* lz4sd = &LZ4_streamDecode->internal_donotuse;
|
|
int result;
|
|
|
|
if (lz4sd->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_GCC_PPC64LE
|
|
int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int originalSize)
|
|
{
|
|
LZ4_streamDecode_t_internal* lz4sd = &LZ4_streamDecode->internal_donotuse;
|
|
int result;
|
|
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() { 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 */
|