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Diffstat (limited to 'lib/lz4/lz4.c')
| -rw-r--r-- | lib/lz4/lz4.c | 1708 |
1 files changed, 0 insertions, 1708 deletions
diff --git a/lib/lz4/lz4.c b/lib/lz4/lz4.c deleted file mode 100644 index 853d228..0000000 --- a/lib/lz4/lz4.c +++ /dev/null @@ -1,1708 +0,0 @@ -/* - LZ4 - Fast LZ compression algorithm - Copyright (C) 2011-present, Yann Collet. - - BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) - - Redistribution and use in source and binary forms, with or without - modification, are permitted provided that the following conditions are - met: - - * Redistributions of source code must retain the above copyright - notice, this list of conditions and the following disclaimer. - * Redistributions in binary form must reproduce the above - copyright notice, this list of conditions and the following disclaimer - in the documentation and/or other materials provided with the - distribution. - - THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR - A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT - OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, - SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT - LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, - DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY - THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT - (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE - OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - - You can contact the author at : - - LZ4 homepage : http://www.lz4.org - - LZ4 source repository : https://github.com/lz4/lz4 -*/ - -/*-************************************ -* Tuning parameters -**************************************/ -/* - * LZ4_HEAPMODE : - * Select how default compression functions will allocate memory for their hash table, - * in memory stack (0:default, fastest), or in memory heap (1:requires malloc()). - */ -#ifndef LZ4_HEAPMODE -# define LZ4_HEAPMODE 0 -#endif - -/* - * ACCELERATION_DEFAULT : - * Select "acceleration" for LZ4_compress_fast() when parameter value <= 0 - */ -#define ACCELERATION_DEFAULT 1 - - -/*-************************************ -* CPU Feature Detection -**************************************/ -/* LZ4_FORCE_MEMORY_ACCESS - * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable. - * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal. - * The below switch allow to select different access method for improved performance. - * Method 0 (default) : use `memcpy()`. Safe and portable. - * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable). - * This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`. - * Method 2 : direct access. This method is portable but violate C standard. - * It can generate buggy code on targets which assembly generation depends on alignment. - * But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6) - * See https://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details. - * Prefer these methods in priority order (0 > 1 > 2) - */ -#ifndef LZ4_FORCE_MEMORY_ACCESS /* can be defined externally */ -# if defined(__GNUC__) && \ - ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) \ - || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) ) -# define LZ4_FORCE_MEMORY_ACCESS 2 -# elif (defined(__INTEL_COMPILER) && !defined(_WIN32)) || defined(__GNUC__) -# define LZ4_FORCE_MEMORY_ACCESS 1 -# endif -#endif - -/* - * LZ4_FORCE_SW_BITCOUNT - * Define this parameter if your target system or compiler does not support hardware bit count - */ -#if defined(_MSC_VER) && defined(_WIN32_WCE) /* Visual Studio for WinCE doesn't support Hardware bit count */ -# define LZ4_FORCE_SW_BITCOUNT -#endif - - - -/*-************************************ -* Dependency -**************************************/ -/* - * LZ4_SRC_INCLUDED: - * Amalgamation flag, whether lz4.c is included - */ -#ifndef LZ4_SRC_INCLUDED -# define LZ4_SRC_INCLUDED 1 -#endif - -#ifndef LZ4_STATIC_LINKING_ONLY -#define LZ4_STATIC_LINKING_ONLY -#endif - -#ifndef LZ4_DISABLE_DEPRECATE_WARNINGS -#define LZ4_DISABLE_DEPRECATE_WARNINGS /* due to LZ4_decompress_safe_withPrefix64k */ -#endif - -#define LZ4_STATIC_LINKING_ONLY /* LZ4_DISTANCE_MAX */ -#include "lz4.h" -/* see also "memory routines" below */ - - -/*-************************************ -* Compiler Options -**************************************/ -#ifdef _MSC_VER /* Visual Studio */ -# include <intrin.h> -# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */ -# pragma warning(disable : 4293) /* disable: C4293: too large shift (32-bits) */ -#endif /* _MSC_VER */ - -#ifndef LZ4_FORCE_INLINE -# ifdef _MSC_VER /* Visual Studio */ -# define LZ4_FORCE_INLINE static __forceinline -# else -# if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */ -# ifdef __GNUC__ -# define LZ4_FORCE_INLINE static inline __attribute__((always_inline)) -# else -# define LZ4_FORCE_INLINE static inline -# endif -# else -# define LZ4_FORCE_INLINE static -# endif /* __STDC_VERSION__ */ -# endif /* _MSC_VER */ -#endif /* LZ4_FORCE_INLINE */ - -/* LZ4_FORCE_O2_GCC_PPC64LE and LZ4_FORCE_O2_INLINE_GCC_PPC64LE - * gcc on ppc64le generates an unrolled SIMDized loop for LZ4_wildCopy8, - * together with a simple 8-byte copy loop as a fall-back path. - * However, this optimization hurts the decompression speed by >30%, - * because the execution does not go to the optimized loop - * for typical compressible data, and all of the preamble checks - * before going to the fall-back path become useless overhead. - * This optimization happens only with the -O3 flag, and -O2 generates - * a simple 8-byte copy loop. - * With gcc on ppc64le, all of the LZ4_decompress_* and LZ4_wildCopy8 - * functions are annotated with __attribute__((optimize("O2"))), - * and also LZ4_wildCopy8 is forcibly inlined, so that the O2 attribute - * of LZ4_wildCopy8 does not affect the compression speed. - */ -#if defined(__PPC64__) && defined(__LITTLE_ENDIAN__) && defined(__GNUC__) && !defined(__clang__) -# define LZ4_FORCE_O2_GCC_PPC64LE __attribute__((optimize("O2"))) -# define LZ4_FORCE_O2_INLINE_GCC_PPC64LE __attribute__((optimize("O2"))) LZ4_FORCE_INLINE -#else -# define LZ4_FORCE_O2_GCC_PPC64LE -# define LZ4_FORCE_O2_INLINE_GCC_PPC64LE static -#endif - -#if (defined(__GNUC__) && (__GNUC__ >= 3)) || (defined(__INTEL_COMPILER) && (__INTEL_COMPILER >= 800)) || defined(__clang__) -# define expect(expr,value) (__builtin_expect ((expr),(value)) ) -#else -# define expect(expr,value) (expr) -#endif - -#ifndef likely -#define likely(expr) expect((expr) != 0, 1) -#endif -#ifndef unlikely -#define unlikely(expr) expect((expr) != 0, 0) -#endif - - -/*-************************************ -* Memory routines -**************************************/ -#include <stdlib.h> /* malloc, calloc, free */ -#define ALLOC(s) malloc(s) -#define ALLOC_AND_ZERO(s) calloc(1,s) -#define FREEMEM(p) free(p) -#include <string.h> /* memset, memcpy */ -#define MEM_INIT(p,v,s) memset((p),(v),(s)) - - -/*-************************************ -* Common Constants -**************************************/ -#define MINMATCH 4 - -#define WILDCOPYLENGTH 8 -#define LASTLITERALS 5 /* see ../doc/lz4_Block_format.md#parsing-restrictions */ -#define MFLIMIT 12 /* see ../doc/lz4_Block_format.md#parsing-restrictions */ -#define MATCH_SAFEGUARD_DISTANCE ((2*WILDCOPYLENGTH) - MINMATCH) /* ensure it's possible to write 2 x wildcopyLength without overflowing output buffer */ -#define FASTLOOP_SAFE_DISTANCE 64 -static const int LZ4_minLength = (MFLIMIT+1); - -#define KB *(1 <<10) -#define MB *(1 <<20) -#define GB *(1U<<30) - -#define LZ4_DISTANCE_ABSOLUTE_MAX 65535 -#if (LZ4_DISTANCE_MAX > LZ4_DISTANCE_ABSOLUTE_MAX) /* max supported by LZ4 format */ -# error "LZ4_DISTANCE_MAX is too big : must be <= 65535" -#endif - -#define ML_BITS 4 -#define ML_MASK ((1U<<ML_BITS)-1) -#define RUN_BITS (8-ML_BITS) -#define RUN_MASK ((1U<<RUN_BITS)-1) - - -/*-************************************ -* Error detection -**************************************/ -#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=1) -# include <assert.h> -#else -# ifndef assert -# define assert(condition) ((void)0) -# endif -#endif - -#define LZ4_STATIC_ASSERT(c) { enum { LZ4_static_assert = 1/(int)(!!(c)) }; } /* use after variable declarations */ - -#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=2) -# include <stdio.h> -static int g_debuglog_enable = 1; -# define DEBUGLOG(l, ...) { \ - if ((g_debuglog_enable) && (l<=LZ4_DEBUG)) { \ - fprintf(stderr, __FILE__ ": "); \ - fprintf(stderr, __VA_ARGS__); \ - fprintf(stderr, " \n"); \ - } } -#else -# define DEBUGLOG(l, ...) {} /* disabled */ -#endif - - -/*-************************************ -* Types -**************************************/ -#if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) -# include <stdint.h> - typedef uint8_t BYTE; - typedef uint16_t U16; - typedef uint32_t U32; - typedef int32_t S32; - typedef uint64_t U64; - typedef uintptr_t uptrval; -#else - typedef unsigned char BYTE; - typedef unsigned short U16; - typedef unsigned int U32; - typedef signed int S32; - typedef unsigned long long U64; - typedef size_t uptrval; /* generally true, except OpenVMS-64 */ -#endif - -#if defined(__x86_64__) - typedef U64 reg_t; /* 64-bits in x32 mode */ -#else - typedef size_t reg_t; /* 32-bits in x32 mode */ -#endif - -typedef enum { - notLimited = 0, - limitedOutput = 1, - fillOutput = 2 -} limitedOutput_directive; - - -/*-************************************ -* Reading and writing into memory -**************************************/ -static unsigned LZ4_isLittleEndian(void) -{ - const union { U32 u; BYTE c[4]; } one = { 1 }; /* don't use static : performance detrimental */ - return one.c[0]; -} - - -#if defined(LZ4_FORCE_MEMORY_ACCESS) && (LZ4_FORCE_MEMORY_ACCESS==2) -/* lie to the compiler about data alignment; use with caution */ - -static U16 LZ4_read16(const void* memPtr) { return *(const U16*) memPtr; } -static U32 LZ4_read32(const void* memPtr) { return *(const U32*) memPtr; } -static reg_t LZ4_read_ARCH(const void* memPtr) { return *(const reg_t*) memPtr; } - -static void LZ4_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; } -static void LZ4_write32(void* memPtr, U32 value) { *(U32*)memPtr = value; } - -#elif defined(LZ4_FORCE_MEMORY_ACCESS) && (LZ4_FORCE_MEMORY_ACCESS==1) - -/* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */ -/* currently only defined for gcc and icc */ -typedef union { U16 u16; U32 u32; reg_t uArch; } __attribute__((packed)) unalign; - -static U16 LZ4_read16(const void* ptr) { return ((const unalign*)ptr)->u16; } -static U32 LZ4_read32(const void* ptr) { return ((const unalign*)ptr)->u32; } -static reg_t LZ4_read_ARCH(const void* ptr) { return ((const unalign*)ptr)->uArch; } - -static void LZ4_write16(void* memPtr, U16 value) { ((unalign*)memPtr)->u16 = value; } -static void LZ4_write32(void* memPtr, U32 value) { ((unalign*)memPtr)->u32 = value; } - -#else /* safe and portable access using memcpy() */ - -static U16 LZ4_read16(const void* memPtr) -{ - U16 val; memcpy(&val, memPtr, sizeof(val)); return val; -} - -static U32 LZ4_read32(const void* memPtr) -{ - U32 val; memcpy(&val, memPtr, sizeof(val)); return val; -} - -static reg_t LZ4_read_ARCH(const void* memPtr) -{ - reg_t val; memcpy(&val, memPtr, sizeof(val)); return val; -} - -static void LZ4_write16(void* memPtr, U16 value) -{ - memcpy(memPtr, &value, sizeof(value)); -} - -static void LZ4_write32(void* memPtr, U32 value) -{ - memcpy(memPtr, &value, sizeof(value)); -} - -#endif /* LZ4_FORCE_MEMORY_ACCESS */ - - -static U16 LZ4_readLE16(const void* memPtr) -{ - if (LZ4_isLittleEndian()) { - return LZ4_read16(memPtr); - } else { - const BYTE* p = (const BYTE*)memPtr; - return (U16)((U16)p[0] + (p[1]<<8)); - } -} - -static void LZ4_writeLE16(void* memPtr, U16 value) -{ - if (LZ4_isLittleEndian()) { - LZ4_write16(memPtr, value); - } else { - BYTE* p = (BYTE*)memPtr; - p[0] = (BYTE) value; - p[1] = (BYTE)(value>>8); - } -} - -/* customized variant of memcpy, which can overwrite up to 8 bytes beyond dstEnd */ -LZ4_FORCE_O2_INLINE_GCC_PPC64LE -void LZ4_wildCopy8(void* dstPtr, const void* srcPtr, void* dstEnd) -{ - BYTE* d = (BYTE*)dstPtr; - const BYTE* s = (const BYTE*)srcPtr; - BYTE* const e = (BYTE*)dstEnd; - - do { memcpy(d,s,8); d+=8; s+=8; } while (d<e); -} - -static const unsigned inc32table[8] = {0, 1, 2, 1, 0, 4, 4, 4}; -static const int dec64table[8] = {0, 0, 0, -1, -4, 1, 2, 3}; - - -#ifndef LZ4_FAST_DEC_LOOP -# if defined(__i386__) || defined(__x86_64__) -# define LZ4_FAST_DEC_LOOP 1 -# elif defined(__aarch64__) && !defined(__clang__) - /* On aarch64, we disable this optimization for clang because on certain - * mobile chipsets and clang, it reduces performance. For more information - * refer to https://github.com/lz4/lz4/pull/707. */ -# define LZ4_FAST_DEC_LOOP 1 -# else -# define LZ4_FAST_DEC_LOOP 0 -# endif -#endif - -#if LZ4_FAST_DEC_LOOP - -LZ4_FORCE_O2_INLINE_GCC_PPC64LE void -LZ4_memcpy_using_offset_base(BYTE* dstPtr, const BYTE* srcPtr, BYTE* dstEnd, const size_t offset) -{ - if (offset < 8) { - dstPtr[0] = srcPtr[0]; - dstPtr[1] = srcPtr[1]; - dstPtr[2] = srcPtr[2]; - dstPtr[3] = srcPtr[3]; - srcPtr += inc32table[offset]; - memcpy(dstPtr+4, srcPtr, 4); - srcPtr -= dec64table[offset]; - dstPtr += 8; - } else { - memcpy(dstPtr, srcPtr, 8); - dstPtr += 8; - srcPtr += 8; - } - - LZ4_wildCopy8(dstPtr, srcPtr, dstEnd); -} - -/* customized variant of memcpy, which can overwrite up to 32 bytes beyond dstEnd - * this version copies two times 16 bytes (instead of one time 32 bytes) - * because it must be compatible with offsets >= 16. */ -LZ4_FORCE_O2_INLINE_GCC_PPC64LE void -LZ4_wildCopy32(void* dstPtr, const void* srcPtr, void* dstEnd) -{ - BYTE* d = (BYTE*)dstPtr; - const BYTE* s = (const BYTE*)srcPtr; - BYTE* const e = (BYTE*)dstEnd; - - do { memcpy(d,s,16); memcpy(d+16,s+16,16); d+=32; s+=32; } while (d<e); -} - -/* LZ4_memcpy_using_offset() presumes : - * - dstEnd >= dstPtr + MINMATCH - * - there is at least 8 bytes available to write after dstEnd */ -LZ4_FORCE_O2_INLINE_GCC_PPC64LE void -LZ4_memcpy_using_offset(BYTE* dstPtr, const BYTE* srcPtr, BYTE* dstEnd, const size_t offset) -{ - BYTE v[8]; - - assert(dstEnd >= dstPtr + MINMATCH); - LZ4_write32(dstPtr, 0); /* silence an msan warning when offset==0 */ - - switch(offset) { - case 1: - memset(v, *srcPtr, 8); - break; - case 2: - memcpy(v, srcPtr, 2); - memcpy(&v[2], srcPtr, 2); - memcpy(&v[4], &v[0], 4); - break; - case 4: - memcpy(v, srcPtr, 4); - memcpy(&v[4], srcPtr, 4); - break; - default: - LZ4_memcpy_using_offset_base(dstPtr, srcPtr, dstEnd, offset); - return; - } - - memcpy(dstPtr, v, 8); - dstPtr += 8; - while (dstPtr < dstEnd) { - memcpy(dstPtr, v, 8); - dstPtr += 8; - } -} -#endif - - -/*-************************************ -* Common functions -**************************************/ -static unsigned LZ4_NbCommonBytes (reg_t val) -{ - 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_compressBound(int isize) { return LZ4_COMPRESSBOUND(isize); } - -/*-****************************** -* 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); - } - } -} - -static 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); -} - -/*-****************************** -* Streaming functions -********************************/ - -#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; -} - -/*-******************************* - * 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); -} - -#endif /* LZ4_COMMONDEFS_ONLY */ |