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691 lines
25 KiB
C
691 lines
25 KiB
C
/*
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LZ4 - Fast LZ compression algorithm
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Copyright (C) 2011-2013, 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://fastcompression.blogspot.com/p/lz4.html
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- LZ4 source repository : http://code.google.com/p/lz4/
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*/
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/*
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Note : this source file requires "lz4_encoder.h"
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*/
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//**************************************
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// Tuning parameters
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//**************************************
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// MEMORY_USAGE :
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// Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
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// Increasing memory usage improves compression ratio
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// Reduced memory usage can improve speed, due to cache effect
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// Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache
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#define MEMORY_USAGE 14
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// HEAPMODE :
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// Select how default compression function will allocate memory for its hash table,
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// in memory stack (0:default, fastest), or in memory heap (1:requires memory allocation (malloc)).
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// Default allocation strategy is to use stack (HEAPMODE 0)
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// Note : explicit functions *_stack* and *_heap* are unaffected by this setting
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#define HEAPMODE 0
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// BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE :
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// This will provide a small boost to performance for big endian cpu, but the resulting compressed stream will be incompatible with little-endian CPU.
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// You can set this option to 1 in situations where data will remain within closed environment
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// This option is useless on Little_Endian CPU (such as x86)
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//#define BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE 1
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//**************************************
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// CPU Feature Detection
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//**************************************
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// 32 or 64 bits ?
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#if (defined(__x86_64__) || defined(_M_X64) || defined(_WIN64) \
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|| defined(__powerpc64__) || defined(__ppc64__) || defined(__PPC64__) \
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|| defined(__64BIT__) || defined(_LP64) || defined(__LP64__) \
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|| defined(__ia64) || defined(__itanium__) || defined(_M_IA64) ) // Detects 64 bits mode
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# define LZ4_ARCH64 1
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#else
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# define LZ4_ARCH64 0
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#endif
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// Little Endian or Big Endian ?
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// Overwrite the #define below if you know your architecture endianess
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#if defined (__GLIBC__)
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# include <endian.h>
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# if (__BYTE_ORDER == __BIG_ENDIAN)
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# define LZ4_BIG_ENDIAN 1
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# endif
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#elif (defined(__BIG_ENDIAN__) || defined(__BIG_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(__LITTLE_ENDIAN__) || defined(__LITTLE_ENDIAN) || defined(_LITTLE_ENDIAN))
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# define LZ4_BIG_ENDIAN 1
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#elif defined(__sparc) || defined(__sparc__) \
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|| defined(__powerpc__) || defined(__ppc__) || defined(__PPC__) \
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|| defined(__hpux) || defined(__hppa) \
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|| defined(_MIPSEB) || defined(__s390__)
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# define LZ4_BIG_ENDIAN 1
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#else
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// Little Endian assumed. PDP Endian and other very rare endian format are unsupported.
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#endif
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// Unaligned memory access is automatically enabled for "common" CPU, such as x86.
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// For others CPU, the compiler will be more cautious, and insert extra code to ensure aligned access is respected
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// If you know your target CPU supports unaligned memory access, you want to force this option manually to improve performance
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#if defined(__ARM_FEATURE_UNALIGNED)
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# define LZ4_FORCE_UNALIGNED_ACCESS 1
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#endif
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// Define this parameter if your target system or compiler does not support hardware bit count
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#if defined(_MSC_VER) && defined(_WIN32_WCE) // Visual Studio for Windows CE does not support Hardware bit count
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# define LZ4_FORCE_SW_BITCOUNT
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#endif
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//**************************************
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// Compiler Options
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//**************************************
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#if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L // C99
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/* "restrict" is a known keyword */
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#else
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# define restrict // Disable restrict
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#endif
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#define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
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#ifdef _MSC_VER // Visual Studio
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# include <intrin.h> // For Visual 2005
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# if LZ4_ARCH64 // 64-bit
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# pragma intrinsic(_BitScanForward64) // For Visual 2005
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# pragma intrinsic(_BitScanReverse64) // For Visual 2005
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# else
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# pragma intrinsic(_BitScanForward) // For Visual 2005
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# pragma intrinsic(_BitScanReverse) // For Visual 2005
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# endif
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# pragma warning(disable : 4127) // disable: C4127: conditional expression is constant
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#endif
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#ifdef _MSC_VER
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# define lz4_bswap16(x) _byteswap_ushort(x)
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#else
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# define lz4_bswap16(x) ((unsigned short int) ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8)))
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#endif
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#if (GCC_VERSION >= 302) || (__INTEL_COMPILER >= 800) || defined(__clang__)
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# define expect(expr,value) (__builtin_expect ((expr),(value)) )
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#else
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# define expect(expr,value) (expr)
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#endif
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#define likely(expr) expect((expr) != 0, 1)
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#define unlikely(expr) expect((expr) != 0, 0)
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//**************************************
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// Includes
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//**************************************
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#include <stdlib.h> // for malloc
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#include <string.h> // for memset
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#include "lz4.h"
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//**************************************
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// Basic Types
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//**************************************
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#if 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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#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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#endif
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#if defined(__GNUC__) && !defined(LZ4_FORCE_UNALIGNED_ACCESS)
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# define _PACKED __attribute__ ((packed))
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#else
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# define _PACKED
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#endif
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#if !defined(LZ4_FORCE_UNALIGNED_ACCESS) && !defined(__GNUC__)
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# pragma pack(push, 1)
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#endif
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typedef struct _U16_S { U16 v; } _PACKED U16_S;
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typedef struct _U32_S { U32 v; } _PACKED U32_S;
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typedef struct _U64_S { U64 v; } _PACKED U64_S;
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#if !defined(LZ4_FORCE_UNALIGNED_ACCESS) && !defined(__GNUC__)
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# pragma pack(pop)
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#endif
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#define A64(x) (((U64_S *)(x))->v)
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#define A32(x) (((U32_S *)(x))->v)
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#define A16(x) (((U16_S *)(x))->v)
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//**************************************
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// Constants
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//**************************************
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#define HASHTABLESIZE (1 << MEMORY_USAGE)
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#define MINMATCH 4
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#define COPYLENGTH 8
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#define LASTLITERALS 5
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#define MFLIMIT (COPYLENGTH+MINMATCH)
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#define MINLENGTH (MFLIMIT+1)
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#define LZ4_64KLIMIT ((1<<16) + (MFLIMIT-1))
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#define SKIPSTRENGTH 6 // Increasing this value will make the compression run slower on incompressible data
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#define MAXD_LOG 16
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#define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
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#define ML_BITS 4
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#define ML_MASK ((1U<<ML_BITS)-1)
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#define RUN_BITS (8-ML_BITS)
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#define RUN_MASK ((1U<<RUN_BITS)-1)
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//**************************************
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// Architecture-specific macros
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//**************************************
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#if LZ4_ARCH64 // 64-bit
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# define STEPSIZE 8
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# define UARCH U64
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# define AARCH A64
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# define LZ4_COPYSTEP(s,d) A64(d) = A64(s); d+=8; s+=8;
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# define LZ4_COPYPACKET(s,d) LZ4_COPYSTEP(s,d)
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# define LZ4_SECURECOPY(s,d,e) if (d<e) LZ4_WILDCOPY(s,d,e)
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# define HTYPE U32
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# define INITBASE(base) const BYTE* const base = ip
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#else // 32-bit
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# define STEPSIZE 4
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# define UARCH U32
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# define AARCH A32
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# define LZ4_COPYSTEP(s,d) A32(d) = A32(s); d+=4; s+=4;
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# define LZ4_COPYPACKET(s,d) LZ4_COPYSTEP(s,d); LZ4_COPYSTEP(s,d);
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# define LZ4_SECURECOPY LZ4_WILDCOPY
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# define HTYPE const BYTE*
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# define INITBASE(base) const int base = 0
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#endif
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#if (defined(LZ4_BIG_ENDIAN) && !defined(BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE))
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# define LZ4_READ_LITTLEENDIAN_16(d,s,p) { U16 v = A16(p); v = lz4_bswap16(v); d = (s) - v; }
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# define LZ4_WRITE_LITTLEENDIAN_16(p,i) { U16 v = (U16)(i); v = lz4_bswap16(v); A16(p) = v; p+=2; }
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#else // Little Endian
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# define LZ4_READ_LITTLEENDIAN_16(d,s,p) { d = (s) - A16(p); }
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# define LZ4_WRITE_LITTLEENDIAN_16(p,v) { A16(p) = v; p+=2; }
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#endif
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//**************************************
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// Macros
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//**************************************
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#define LZ4_WILDCOPY(s,d,e) do { LZ4_COPYPACKET(s,d) } while (d<e);
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#define LZ4_BLINDCOPY(s,d,l) { BYTE* e=(d)+(l); LZ4_WILDCOPY(s,d,e); d=e; }
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//****************************
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// Private functions
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//****************************
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#if LZ4_ARCH64
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static inline int LZ4_NbCommonBytes (register U64 val)
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{
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#if defined(LZ4_BIG_ENDIAN)
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#if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
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unsigned long r = 0;
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_BitScanReverse64( &r, val );
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return (int)(r>>3);
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#elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
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return (__builtin_clzll(val) >> 3);
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#else
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int r;
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if (!(val>>32)) { r=4; } else { r=0; val>>=32; }
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if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
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r += (!val);
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return r;
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#endif
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#else
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#if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
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unsigned long r = 0;
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_BitScanForward64( &r, val );
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return (int)(r>>3);
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#elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
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return (__builtin_ctzll(val) >> 3);
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#else
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static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2, 0, 3, 1, 3, 1, 4, 2, 7, 0, 2, 3, 6, 1, 5, 3, 5, 1, 3, 4, 4, 2, 5, 6, 7, 7, 0, 1, 2, 3, 3, 4, 6, 2, 6, 5, 5, 3, 4, 5, 6, 7, 1, 2, 4, 6, 4, 4, 5, 7, 2, 6, 5, 7, 6, 7, 7 };
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return DeBruijnBytePos[((U64)((val & -val) * 0x0218A392CDABBD3F)) >> 58];
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#endif
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#endif
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}
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#else
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static inline int LZ4_NbCommonBytes (register U32 val)
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{
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#if defined(LZ4_BIG_ENDIAN)
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# if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
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unsigned long r = 0;
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_BitScanReverse( &r, val );
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return (int)(r>>3);
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# elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
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return (__builtin_clz(val) >> 3);
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# else
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int r;
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if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
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r += (!val);
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return r;
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# endif
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#else
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# if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
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unsigned long r;
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_BitScanForward( &r, val );
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return (int)(r>>3);
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# elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
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return (__builtin_ctz(val) >> 3);
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# else
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static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0, 3, 2, 2, 1, 3, 2, 0, 1, 3, 3, 1, 2, 2, 2, 2, 0, 3, 1, 2, 0, 1, 0, 1, 1 };
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return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27];
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# endif
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#endif
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}
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#endif
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//******************************
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// Compression functions
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//******************************
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/*
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int LZ4_compress_stack(
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const char* source,
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char* dest,
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int inputSize)
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Compress 'inputSize' bytes from 'source' into an output buffer 'dest'.
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Destination buffer must be already allocated, and sized at a minimum of LZ4_compressBound(inputSize).
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return : the number of bytes written in buffer 'dest'
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*/
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#define FUNCTION_NAME LZ4_compress_stack
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#include "lz4_encoder.h"
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/*
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int LZ4_compress_stack_limitedOutput(
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const char* source,
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char* dest,
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int inputSize,
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int maxOutputSize)
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Compress 'inputSize' bytes from 'source' into an output buffer 'dest' of maximum size 'maxOutputSize'.
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If it cannot achieve it, compression will stop, and result of the function will be zero.
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return : the number of bytes written in buffer 'dest', or 0 if the compression fails
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*/
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#define FUNCTION_NAME LZ4_compress_stack_limitedOutput
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#define LIMITED_OUTPUT
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#include "lz4_encoder.h"
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/*
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int LZ4_compress64k_stack(
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const char* source,
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char* dest,
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int inputSize)
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Compress 'inputSize' bytes from 'source' into an output buffer 'dest'.
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This function compresses better than LZ4_compress_stack(), on the condition that
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'inputSize' must be < to LZ4_64KLIMIT, or the function will fail.
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Destination buffer must be already allocated, and sized at a minimum of LZ4_compressBound(inputSize).
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return : the number of bytes written in buffer 'dest', or 0 if compression fails
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*/
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#define FUNCTION_NAME LZ4_compress64k_stack
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#define COMPRESS_64K
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#include "lz4_encoder.h"
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/*
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int LZ4_compress64k_stack_limitedOutput(
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const char* source,
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char* dest,
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int inputSize,
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int maxOutputSize)
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Compress 'inputSize' bytes from 'source' into an output buffer 'dest' of maximum size 'maxOutputSize'.
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This function compresses better than LZ4_compress_stack_limitedOutput(), on the condition that
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'inputSize' must be < to LZ4_64KLIMIT, or the function will fail.
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If it cannot achieve it, compression will stop, and result of the function will be zero.
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return : the number of bytes written in buffer 'dest', or 0 if the compression fails
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*/
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#define FUNCTION_NAME LZ4_compress64k_stack_limitedOutput
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#define COMPRESS_64K
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#define LIMITED_OUTPUT
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#include "lz4_encoder.h"
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/*
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void* LZ4_createHeapMemory();
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int LZ4_freeHeapMemory(void* ctx);
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Used to allocate and free hashTable memory
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to be used by the LZ4_compress_heap* family of functions.
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LZ4_createHeapMemory() returns NULL is memory allocation fails.
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*/
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void* LZ4_create() { return malloc(HASHTABLESIZE); }
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int LZ4_free(void* ctx) { free(ctx); return 0; }
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/*
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int LZ4_compress_heap(
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void* ctx,
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const char* source,
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char* dest,
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int inputSize)
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Compress 'inputSize' bytes from 'source' into an output buffer 'dest'.
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The memory used for compression must be created by LZ4_createHeapMemory() and provided by pointer 'ctx'.
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Destination buffer must be already allocated, and sized at a minimum of LZ4_compressBound(inputSize).
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return : the number of bytes written in buffer 'dest'
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*/
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#define FUNCTION_NAME LZ4_compress_heap
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#define USE_HEAPMEMORY
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#include "lz4_encoder.h"
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/*
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int LZ4_compress_heap_limitedOutput(
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void* ctx,
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const char* source,
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char* dest,
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int inputSize,
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int maxOutputSize)
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Compress 'inputSize' bytes from 'source' into an output buffer 'dest' of maximum size 'maxOutputSize'.
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If it cannot achieve it, compression will stop, and result of the function will be zero.
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The memory used for compression must be created by LZ4_createHeapMemory() and provided by pointer 'ctx'.
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return : the number of bytes written in buffer 'dest', or 0 if the compression fails
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*/
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#define FUNCTION_NAME LZ4_compress_heap_limitedOutput
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#define LIMITED_OUTPUT
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#define USE_HEAPMEMORY
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#include "lz4_encoder.h"
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/*
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int LZ4_compress64k_heap(
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void* ctx,
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const char* source,
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char* dest,
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int inputSize)
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Compress 'inputSize' bytes from 'source' into an output buffer 'dest'.
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The memory used for compression must be created by LZ4_createHeapMemory() and provided by pointer 'ctx'.
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'inputSize' must be < to LZ4_64KLIMIT, or the function will fail.
|
|
Destination buffer must be already allocated, and sized at a minimum of LZ4_compressBound(inputSize).
|
|
return : the number of bytes written in buffer 'dest'
|
|
*/
|
|
#define FUNCTION_NAME LZ4_compress64k_heap
|
|
#define COMPRESS_64K
|
|
#define USE_HEAPMEMORY
|
|
#include "lz4_encoder.h"
|
|
|
|
|
|
/*
|
|
int LZ4_compress64k_heap_limitedOutput(
|
|
void* ctx,
|
|
const char* source,
|
|
char* dest,
|
|
int inputSize,
|
|
int maxOutputSize)
|
|
|
|
Compress 'inputSize' bytes from 'source' into an output buffer 'dest' of maximum size 'maxOutputSize'.
|
|
If it cannot achieve it, compression will stop, and result of the function will be zero.
|
|
The memory used for compression must be created by LZ4_createHeapMemory() and provided by pointer 'ctx'.
|
|
'inputSize' must be < to LZ4_64KLIMIT, or the function will fail.
|
|
return : the number of bytes written in buffer 'dest', or 0 if the compression fails
|
|
*/
|
|
#define FUNCTION_NAME LZ4_compress64k_heap_limitedOutput
|
|
#define COMPRESS_64K
|
|
#define LIMITED_OUTPUT
|
|
#define USE_HEAPMEMORY
|
|
#include "lz4_encoder.h"
|
|
|
|
|
|
int LZ4_compress(const char* source, char* dest, int inputSize)
|
|
{
|
|
#if HEAPMODE
|
|
void* ctx = LZ4_create();
|
|
int result;
|
|
if (ctx == NULL) return 0; // Failed allocation => compression not done
|
|
if (inputSize < LZ4_64KLIMIT)
|
|
result = LZ4_compress64k_heap(ctx, source, dest, inputSize);
|
|
else result = LZ4_compress_heap(ctx, source, dest, inputSize);
|
|
LZ4_free(ctx);
|
|
return result;
|
|
#else
|
|
if (inputSize < (int)LZ4_64KLIMIT) return LZ4_compress64k_stack(source, dest, inputSize);
|
|
return LZ4_compress_stack(source, dest, inputSize);
|
|
#endif
|
|
}
|
|
|
|
|
|
int LZ4_compress_limitedOutput(const char* source, char* dest, int inputSize, int maxOutputSize)
|
|
{
|
|
#if HEAPMODE
|
|
void* ctx = LZ4_create();
|
|
int result;
|
|
if (ctx == NULL) return 0; // Failed allocation => compression not done
|
|
if (inputSize < LZ4_64KLIMIT)
|
|
result = LZ4_compress64k_heap_limitedOutput(ctx, source, dest, inputSize, maxOutputSize);
|
|
else result = LZ4_compress_heap_limitedOutput(ctx, source, dest, inputSize, maxOutputSize);
|
|
LZ4_free(ctx);
|
|
return result;
|
|
#else
|
|
if (inputSize < (int)LZ4_64KLIMIT) return LZ4_compress64k_stack_limitedOutput(source, dest, inputSize, maxOutputSize);
|
|
return LZ4_compress_stack_limitedOutput(source, dest, inputSize, maxOutputSize);
|
|
#endif
|
|
}
|
|
|
|
|
|
//****************************
|
|
// Decompression functions
|
|
//****************************
|
|
|
|
typedef enum { noPrefix = 0, withPrefix = 1 } prefix64k_directive;
|
|
typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } end_directive;
|
|
typedef enum { full = 0, partial = 1 } exit_directive;
|
|
|
|
|
|
// This generic decompression function cover all use cases.
|
|
// It shall be instanciated several times, using different sets of directives
|
|
// Note that it is essential this generic function is really inlined,
|
|
// in order to remove useless branches during compilation optimisation.
|
|
static inline int LZ4_decompress_generic(
|
|
const char* source,
|
|
char* dest,
|
|
int inputSize, //
|
|
int outputSize, // OutputSize must be != 0; if endOnInput==endOnInputSize, this value is the max size of Output Buffer.
|
|
|
|
int endOnInput, // endOnOutputSize, endOnInputSize
|
|
int prefix64k, // noPrefix, withPrefix
|
|
int partialDecoding, // full, partial
|
|
int targetOutputSize // only used if partialDecoding==partial
|
|
)
|
|
{
|
|
// Local Variables
|
|
const BYTE* restrict ip = (const BYTE*) source;
|
|
const BYTE* ref;
|
|
const BYTE* const iend = ip + inputSize;
|
|
|
|
BYTE* op = (BYTE*) dest;
|
|
BYTE* const oend = op + outputSize;
|
|
BYTE* cpy;
|
|
BYTE* oexit = op + targetOutputSize;
|
|
|
|
size_t dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0};
|
|
#if LZ4_ARCH64
|
|
size_t dec64table[] = {0, 0, 0, (size_t)-1, 0, 1, 2, 3};
|
|
#endif
|
|
|
|
|
|
// Special case
|
|
if ((partialDecoding) && (oexit> oend-MFLIMIT)) oexit = oend-MFLIMIT; // targetOutputSize too large, better decode everything
|
|
if unlikely(outputSize==0) goto _output_error; // Empty output buffer
|
|
|
|
|
|
// Main Loop
|
|
while (1)
|
|
{
|
|
unsigned token;
|
|
size_t length;
|
|
|
|
// get runlength
|
|
token = *ip++;
|
|
if ((length=(token>>ML_BITS)) == RUN_MASK)
|
|
{
|
|
unsigned s=255;
|
|
while (((endOnInput)?ip<iend:1) && (s==255))
|
|
{
|
|
s = *ip++;
|
|
length += s;
|
|
}
|
|
}
|
|
|
|
// copy literals
|
|
cpy = op+length;
|
|
if (((endOnInput) && ((cpy>(partialDecoding?oexit:oend-MFLIMIT)) || (ip+length>iend-(2+1+LASTLITERALS))) )
|
|
|| ((!endOnInput) && (cpy>oend-COPYLENGTH)))
|
|
{
|
|
if (partialDecoding)
|
|
{
|
|
if (cpy > oend) goto _output_error; // Error : write attempt beyond end of output buffer
|
|
if ((endOnInput) && (ip+length > iend)) goto _output_error; // Error : read attempt beyond end of input buffer
|
|
}
|
|
else
|
|
{
|
|
if ((!endOnInput) && (cpy != oend)) goto _output_error; // Error : block decoding must stop exactly there, due to parsing restrictions
|
|
if ((endOnInput) && ((ip+length != iend) || (cpy > oend))) goto _output_error; // Error : not enough place for another match (min 4) + 5 literals
|
|
}
|
|
memcpy(op, ip, length);
|
|
ip += length;
|
|
op += length;
|
|
break; // Necessarily EOF, due to parsing restrictions
|
|
}
|
|
LZ4_WILDCOPY(ip, op, cpy); ip -= (op-cpy); op = cpy;
|
|
|
|
// get offset
|
|
LZ4_READ_LITTLEENDIAN_16(ref,cpy,ip); ip+=2;
|
|
if ((prefix64k==noPrefix) && unlikely(ref < (BYTE* const)dest)) goto _output_error; // Error : offset outside destination buffer
|
|
|
|
// get matchlength
|
|
if ((length=(token&ML_MASK)) == ML_MASK)
|
|
{
|
|
while (endOnInput ? ip<iend-(LASTLITERALS+1) : 1) // A minimum nb of input bytes must remain for LASTLITERALS + token
|
|
{
|
|
unsigned s = *ip++;
|
|
length += s;
|
|
if (s==255) continue;
|
|
break;
|
|
}
|
|
}
|
|
|
|
// copy repeated sequence
|
|
if unlikely((op-ref)<STEPSIZE)
|
|
{
|
|
#if LZ4_ARCH64
|
|
size_t dec64 = dec64table[op-ref];
|
|
#else
|
|
const size_t dec64 = 0;
|
|
#endif
|
|
op[0] = ref[0];
|
|
op[1] = ref[1];
|
|
op[2] = ref[2];
|
|
op[3] = ref[3];
|
|
op += 4, ref += 4; ref -= dec32table[op-ref];
|
|
A32(op) = A32(ref);
|
|
op += STEPSIZE-4; ref -= dec64;
|
|
} else { LZ4_COPYSTEP(ref,op); }
|
|
cpy = op + length - (STEPSIZE-4);
|
|
|
|
if unlikely(cpy>oend-(COPYLENGTH)-(STEPSIZE-4))
|
|
{
|
|
if (cpy > oend-LASTLITERALS) goto _output_error; // Error : last 5 bytes must be literals
|
|
LZ4_SECURECOPY(ref, op, (oend-COPYLENGTH));
|
|
while(op<cpy) *op++=*ref++;
|
|
op=cpy;
|
|
continue;
|
|
}
|
|
LZ4_WILDCOPY(ref, op, cpy);
|
|
op=cpy; // correction
|
|
}
|
|
|
|
// end of decoding
|
|
if (endOnInput)
|
|
return (int) (((char*)op)-dest); // Nb of output bytes decoded
|
|
else
|
|
return (int) (((char*)ip)-source); // Nb of input bytes read
|
|
|
|
// Overflow error detected
|
|
_output_error:
|
|
return (int) (-(((char*)ip)-source))-1;
|
|
}
|
|
|
|
|
|
int LZ4_decompress_safe(const char* source, char* dest, int inputSize, int maxOutputSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, inputSize, maxOutputSize, endOnInputSize, noPrefix, full, 0);
|
|
}
|
|
|
|
int LZ4_decompress_fast(const char* source, char* dest, int outputSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, 0, outputSize, endOnOutputSize, noPrefix, full, 0);
|
|
}
|
|
|
|
int LZ4_decompress_safe_withPrefix64k(const char* source, char* dest, int inputSize, int maxOutputSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, inputSize, maxOutputSize, endOnInputSize, withPrefix, full, 0);
|
|
}
|
|
|
|
int LZ4_decompress_fast_withPrefix64k(const char* source, char* dest, int outputSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, 0, outputSize, endOnOutputSize, withPrefix, full, 0);
|
|
}
|
|
|
|
int LZ4_decompress_safe_partial(const char* source, char* dest, int inputSize, int targetOutputSize, int maxOutputSize)
|
|
{
|
|
return LZ4_decompress_generic(source, dest, inputSize, maxOutputSize, endOnInputSize, noPrefix, partial, targetOutputSize);
|
|
}
|
|
|