diff options
Diffstat (limited to 'lib/lz4')
| -rw-r--r-- | lib/lz4/Makemodule.am | 10 | ||||
| -rw-r--r-- | lib/lz4/README | 12 | ||||
| -rw-r--r-- | lib/lz4/lz4.c | 1708 | ||||
| -rw-r--r-- | lib/lz4/lz4.h | 341 | ||||
| -rw-r--r-- | lib/lz4/lz4hc.c | 1343 | ||||
| -rw-r--r-- | lib/lz4/lz4hc.h | 307 |
6 files changed, 3721 insertions, 0 deletions
diff --git a/lib/lz4/Makemodule.am b/lib/lz4/Makemodule.am new file mode 100644 index 0000000..89e480f --- /dev/null +++ b/lib/lz4/Makemodule.am @@ -0,0 +1,10 @@ +if WITH_OWN_LZ4 +liblz4_la_SOURCES = lib/lz4/lz4.c lib/lz4/lz4.h +liblz4_la_SOURCES += lib/lz4/lz4hc.c lib/lz4/lz4hc.h + +liblz4_la_CPPFLAGS = -I$(top_srcdir)/lib/lz4 -DLZ4_HEAPMODE=1 + +noinst_LTLIBRARIES += liblz4.la +endif + +EXTRA_DIST += lib/lz4/README diff --git a/lib/lz4/README b/lib/lz4/README new file mode 100644 index 0000000..4c15347 --- /dev/null +++ b/lib/lz4/README @@ -0,0 +1,12 @@ +This source has been extracted from the lz4 release tarball, version 1.9.2 +released on August 20th, 2019. + +The source code originates from the "lib" subdirectory. The license is included +in the subdirectory licenses/LZ4.txt in the tools-ng subdirectory of the +squashfs-tools-ng source package. + +The following modifications have been made: + - Always define LZ4LIB_API and LZ4LIB_STATIC_API to set default visibility to + hidden, so the LZ4 functions aren't exported from libsquashfs. + - Remove the streaming functions and most of the functions that aren't used + by libsquashfs. diff --git a/lib/lz4/lz4.c b/lib/lz4/lz4.c new file mode 100644 index 0000000..853d228 --- /dev/null +++ b/lib/lz4/lz4.c @@ -0,0 +1,1708 @@ +/* + 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 */ diff --git a/lib/lz4/lz4.h b/lib/lz4/lz4.h new file mode 100644 index 0000000..43d3b14 --- /dev/null +++ b/lib/lz4/lz4.h @@ -0,0 +1,341 @@ +/* + * LZ4 - Fast LZ compression algorithm + * Header File + * 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 +*/ +#if defined (__cplusplus) +extern "C" { +#endif + +#ifndef LZ4_H_2983827168210 +#define LZ4_H_2983827168210 + +/* --- Dependency --- */ +#include <stddef.h> /* size_t */ + + +/** + Introduction + + LZ4 is lossless compression algorithm, providing compression speed >500 MB/s per core, + scalable with multi-cores CPU. It features an extremely fast decoder, with speed in + multiple GB/s per core, typically reaching RAM speed limits on multi-core systems. + + The LZ4 compression library provides in-memory compression and decompression functions. + It gives full buffer control to user. + Compression can be done in: + - a single step (described as Simple Functions) + - a single step, reusing a context (described in Advanced Functions) + - unbounded multiple steps (described as Streaming compression) + + lz4.h generates and decodes LZ4-compressed blocks (doc/lz4_Block_format.md). + Decompressing such a compressed block requires additional metadata. + Exact metadata depends on exact decompression function. + For the typical case of LZ4_decompress_safe(), + metadata includes block's compressed size, and maximum bound of decompressed size. + Each application is free to encode and pass such metadata in whichever way it wants. + + lz4.h only handle blocks, it can not generate Frames. + + Blocks are different from Frames (doc/lz4_Frame_format.md). + Frames bundle both blocks and metadata in a specified manner. + Embedding metadata is required for compressed data to be self-contained and portable. + Frame format is delivered through a companion API, declared in lz4frame.h. + The `lz4` CLI can only manage frames. +*/ + +/*^*************************************************************** +* Export parameters +*****************************************************************/ +/* +* LZ4_DLL_EXPORT : +* Enable exporting of functions when building a Windows DLL +* LZ4LIB_VISIBILITY : +* Control library symbols visibility. +*/ +#ifndef LZ4LIB_VISIBILITY +# if defined(__GNUC__) && (__GNUC__ >= 4) +# define LZ4LIB_VISIBILITY __attribute__ ((visibility ("hidden"))) +# else +# define LZ4LIB_VISIBILITY +# endif +#endif + +#define LZ4LIB_API LZ4LIB_VISIBILITY + +/*------ Version ------*/ +#define LZ4_QUOTE(str) #str +#define LZ4_EXPAND_AND_QUOTE(str) LZ4_QUOTE(str) +#define LZ4_VERSION_STRING LZ4_EXPAND_AND_QUOTE(LZ4_LIB_VERSION) + +/*-************************************ +* Tuning parameter +**************************************/ +/*! + * LZ4_MEMORY_USAGE : + * Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.) + * Increasing memory usage improves compression ratio. + * Reduced memory usage may improve speed, thanks to better cache locality. + * Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache + */ +#ifndef LZ4_MEMORY_USAGE +# define LZ4_MEMORY_USAGE 14 +#endif + + +/*-************************************ +* Simple Functions +**************************************/ +/*! LZ4_compress_default() : + * Compresses 'srcSize' bytes from buffer 'src' + * into already allocated 'dst' buffer of size 'dstCapacity'. + * Compression is guaranteed to succeed if 'dstCapacity' >= LZ4_compressBound(srcSize). + * It also runs faster, so it's a recommended setting. + * If the function cannot compress 'src' into a more limited 'dst' budget, + * compression stops *immediately*, and the function result is zero. + * In which case, 'dst' content is undefined (invalid). + * srcSize : max supported value is LZ4_MAX_INPUT_SIZE. + * dstCapacity : size of buffer 'dst' (which must be already allocated) + * @return : the number of bytes written into buffer 'dst' (necessarily <= dstCapacity) + * or 0 if compression fails + * Note : This function is protected against buffer overflow scenarios (never writes outside 'dst' buffer, nor read outside 'source' buffer). + */ +LZ4LIB_API int LZ4_compress_default(const char* src, char* dst, int srcSize, int dstCapacity); + +/*! LZ4_decompress_safe() : + * compressedSize : is the exact complete size of the compressed block. + * dstCapacity : is the size of destination buffer (which must be already allocated), presumed an upper bound of decompressed size. + * @return : the number of bytes decompressed into destination buffer (necessarily <= dstCapacity) + * If destination buffer is not large enough, decoding will stop and output an error code (negative value). + * If the source stream is detected malformed, the function will stop decoding and return a negative result. + * Note 1 : This function is protected against malicious data packets : + * it will never writes outside 'dst' buffer, nor read outside 'source' buffer, + * even if the compressed block is maliciously modified to order the decoder to do these actions. + * In such case, the decoder stops immediately, and considers the compressed block malformed. + * Note 2 : compressedSize and dstCapacity must be provided to the function, the compressed block does not contain them. + * The implementation is free to send / store / derive this information in whichever way is most beneficial. + * If there is a need for a different format which bundles together both compressed data and its metadata, consider looking at lz4frame.h instead. + */ +LZ4LIB_API int LZ4_decompress_safe (const char* src, char* dst, int compressedSize, int dstCapacity); + + +/*-************************************ +* Advanced Functions +**************************************/ +#define LZ4_MAX_INPUT_SIZE 0x7E000000 /* 2 113 929 216 bytes */ +#define LZ4_COMPRESSBOUND(isize) ((unsigned)(isize) > (unsigned)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16) + +/*! LZ4_compressBound() : + Provides the maximum size that LZ4 compression may output in a "worst case" scenario (input data not compressible) + This function is primarily useful for memory allocation purposes (destination buffer size). + Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example). + Note that LZ4_compress_default() compresses faster when dstCapacity is >= LZ4_compressBound(srcSize) + inputSize : max supported value is LZ4_MAX_INPUT_SIZE + return : maximum output size in a "worst case" scenario + or 0, if input size is incorrect (too large or negative) +*/ +LZ4LIB_API int LZ4_compressBound(int inputSize); + + +/*! LZ4_compress_fast_extState() : + * Same as LZ4_compress_fast(), using an externally allocated memory space for its state. + * Use LZ4_sizeofState() to know how much memory must be allocated, + * and allocate it on 8-bytes boundaries (using `malloc()` typically). + * Then, provide this buffer as `void* state` to compression function. + */ +LZ4LIB_API int LZ4_sizeofState(void); +LZ4LIB_API int LZ4_compress_fast_extState (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration); + +/*-********************************************* +* Streaming Compression Functions +***********************************************/ +typedef union LZ4_stream_u LZ4_stream_t; /* incomplete type (defined later) */ + +/*-********************************************** +* Streaming Decompression Functions +* Bufferless synchronous API +************************************************/ +typedef union LZ4_streamDecode_u LZ4_streamDecode_t; /* tracking context */ + +#endif /* LZ4_H_2983827168210 */ + + +/*^************************************* + * !!!!!! STATIC LINKING ONLY !!!!!! + ***************************************/ + +/*-**************************************************************************** + * Experimental section + * + * Symbols declared in this section must be considered unstable. Their + * signatures or semantics may change, or they may be removed altogether in the + * future. They are therefore only safe to depend on when the caller is + * statically linked against the library. + * + * To protect against unsafe usage, not only are the declarations guarded, + * the definitions are hidden by default + * when building LZ4 as a shared/dynamic library. + * + * In order to access these declarations, + * define LZ4_STATIC_LINKING_ONLY in your application + * before including LZ4's headers. + * + * In order to make their implementations accessible dynamically, you must + * define LZ4_PUBLISH_STATIC_FUNCTIONS when building the LZ4 library. + ******************************************************************************/ + +#ifdef LZ4_STATIC_LINKING_ONLY + +#ifndef LZ4_STATIC_3504398509 +#define LZ4_STATIC_3504398509 + +#define LZ4LIB_STATIC_API LZ4LIB_API + +#ifndef LZ4_DISTANCE_MAX /* history window size; can be user-defined at compile time */ +# define LZ4_DISTANCE_MAX 65535 /* set to maximum value by default */ +#endif + +#endif /* LZ4_STATIC_3504398509 */ +#endif /* LZ4_STATIC_LINKING_ONLY */ + + + +#ifndef LZ4_H_98237428734687 +#define LZ4_H_98237428734687 + +/*-************************************************************ + * PRIVATE DEFINITIONS + ************************************************************** + * Do not use these definitions directly. + * They are only exposed to allow static allocation of `LZ4_stream_t` and `LZ4_streamDecode_t`. + * Accessing members will expose code to API and/or ABI break in future versions of the library. + **************************************************************/ +#define LZ4_HASHLOG (LZ4_MEMORY_USAGE-2) +#define LZ4_HASHTABLESIZE (1 << LZ4_MEMORY_USAGE) +#define LZ4_HASH_SIZE_U32 (1 << LZ4_HASHLOG) /* required as macro for static allocation */ + +#if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) +#include <stdint.h> + +typedef struct LZ4_stream_t_internal LZ4_stream_t_internal; +struct LZ4_stream_t_internal { + uint32_t hashTable[LZ4_HASH_SIZE_U32]; + uint32_t currentOffset; + uint16_t dirty; + uint16_t tableType; + const uint8_t* dictionary; + const LZ4_stream_t_internal* dictCtx; + uint32_t dictSize; +}; + +typedef struct { + const uint8_t* externalDict; + size_t extDictSize; + const uint8_t* prefixEnd; + size_t prefixSize; +} LZ4_streamDecode_t_internal; + +#else + +typedef struct LZ4_stream_t_internal LZ4_stream_t_internal; +struct LZ4_stream_t_internal { + unsigned int hashTable[LZ4_HASH_SIZE_U32]; + unsigned int currentOffset; + unsigned short dirty; + unsigned short tableType; + const unsigned char* dictionary; + const LZ4_stream_t_internal* dictCtx; + unsigned int dictSize; +}; + +typedef struct { + const unsigned char* externalDict; + const unsigned char* prefixEnd; + size_t extDictSize; + size_t prefixSize; +} LZ4_streamDecode_t_internal; + +#endif + +/*! LZ4_stream_t : + * information structure to track an LZ4 stream. + * LZ4_stream_t can also be created using LZ4_createStream(), which is recommended. + * The structure definition can be convenient for static allocation + * (on stack, or as part of larger structure). + * Init this structure with LZ4_initStream() before first use. + * note : only use this definition in association with static linking ! + * this definition is not API/ABI safe, and may change in a future version. + */ +#define LZ4_STREAMSIZE_U64 ((1 << (LZ4_MEMORY_USAGE-3)) + 4 + ((sizeof(void*)==16) ? 4 : 0) /*AS-400*/ ) +#define LZ4_STREAMSIZE (LZ4_STREAMSIZE_U64 * sizeof(unsigned long long)) +union LZ4_stream_u { + unsigned long long table[LZ4_STREAMSIZE_U64]; + LZ4_stream_t_internal internal_donotuse; +} ; /* previously typedef'd to LZ4_stream_t */ + +/*! LZ4_initStream() : v1.9.0+ + * An LZ4_stream_t structure must be initialized at least once. + * This is automatically done when invoking LZ4_createStream(), + * but it's not when the structure is simply declared on stack (for example). + * + * Use LZ4_initStream() to properly initialize a newly declared LZ4_stream_t. + * It can also initialize any arbitrary buffer of sufficient size, + * and will @return a pointer of proper type upon initialization. + * + * Note : initialization fails if size and alignment conditions are not respected. + * In which case, the function will @return NULL. + * Note2: An LZ4_stream_t structure guarantees correct alignment and size. + * Note3: Before v1.9.0, use LZ4_resetStream() instead + */ +LZ4LIB_API LZ4_stream_t* LZ4_initStream (void* buffer, size_t size); + + +/*! LZ4_streamDecode_t : + * information structure to track an LZ4 stream during decompression. + * init this structure using LZ4_setStreamDecode() before first use. + * note : only use in association with static linking ! + * this definition is not API/ABI safe, + * and may change in a future version ! + */ +#define LZ4_STREAMDECODESIZE_U64 (4 + ((sizeof(void*)==16) ? 2 : 0) /*AS-400*/ ) +#define LZ4_STREAMDECODESIZE (LZ4_STREAMDECODESIZE_U64 * sizeof(unsigned long long)) +union LZ4_streamDecode_u { + unsigned long long table[LZ4_STREAMDECODESIZE_U64]; + LZ4_streamDecode_t_internal internal_donotuse; +} ; /* previously typedef'd to LZ4_streamDecode_t */ + +#endif /* LZ4_H_98237428734687 */ + + +#if defined (__cplusplus) +} +#endif diff --git a/lib/lz4/lz4hc.c b/lib/lz4/lz4hc.c new file mode 100644 index 0000000..4bdf96e --- /dev/null +++ b/lib/lz4/lz4hc.c @@ -0,0 +1,1343 @@ +/* + LZ4 HC - High Compression Mode of LZ4 + Copyright (C) 2011-2017, Yann Collet. + + BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are + met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above + copyright notice, this list of conditions and the following disclaimer + in the documentation and/or other materials provided with the + distribution. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + + You can contact the author at : + - LZ4 source repository : https://github.com/lz4/lz4 + - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c +*/ +/* note : lz4hc is not an independent module, it requires lz4.h/lz4.c for proper compilation */ + + +/* ************************************* +* Tuning Parameter +***************************************/ + +/*! HEAPMODE : + * Select how default compression function will allocate workplace memory, + * in stack (0:fastest), or in heap (1:requires malloc()). + * Since workplace is rather large, heap mode is recommended. + */ +#ifndef LZ4HC_HEAPMODE +# define LZ4HC_HEAPMODE 1 +#endif + + +/*=== Dependency ===*/ +#define LZ4_HC_STATIC_LINKING_ONLY +#include "lz4hc.h" + + +/*=== Common LZ4 definitions ===*/ +#if defined(__GNUC__) +# pragma GCC diagnostic ignored "-Wunused-function" +#endif +#if defined (__clang__) +# pragma clang diagnostic ignored "-Wunused-function" +#endif + +/*=== Enums ===*/ +typedef enum { noDictCtx, usingDictCtxHc } dictCtx_directive; + + +#define LZ4_COMMONDEFS_ONLY +#ifndef LZ4_SRC_INCLUDED +#include "lz4.c" /* LZ4_count, constants, mem */ +#endif + +/*=== Constants ===*/ +#define OPTIMAL_ML (int)((ML_MASK-1)+MINMATCH) +#define LZ4_OPT_NUM (1<<12) + + +/*=== Macros ===*/ +#define MIN(a,b) ( (a) < (b) ? (a) : (b) ) +#define MAX(a,b) ( (a) > (b) ? (a) : (b) ) +#define HASH_FUNCTION(i) (((i) * 2654435761U) >> ((MINMATCH*8)-LZ4HC_HASH_LOG)) +#define DELTANEXTMAXD(p) chainTable[(p) & LZ4HC_MAXD_MASK] /* flexible, LZ4HC_MAXD dependent */ +#define DELTANEXTU16(table, pos) table[(U16)(pos)] /* faster */ +/* Make fields passed to, and updated by LZ4HC_encodeSequence explicit */ +#define UPDATABLE(ip, op, anchor) &ip, &op, &anchor + +static U32 LZ4HC_hashPtr(const void* ptr) { return HASH_FUNCTION(LZ4_read32(ptr)); } + + +/************************************** +* HC Compression +**************************************/ +static void LZ4HC_clearTables (LZ4HC_CCtx_internal* hc4) +{ + MEM_INIT((void*)hc4->hashTable, 0, sizeof(hc4->hashTable)); + MEM_INIT(hc4->chainTable, 0xFF, sizeof(hc4->chainTable)); +} + +static void LZ4HC_init_internal (LZ4HC_CCtx_internal* hc4, const BYTE* start) +{ + uptrval startingOffset = (uptrval)(hc4->end - hc4->base); + if (startingOffset > 1 GB) { + LZ4HC_clearTables(hc4); + startingOffset = 0; + } + startingOffset += 64 KB; + hc4->nextToUpdate = (U32) startingOffset; + hc4->base = start - startingOffset; + hc4->end = start; + hc4->dictBase = start - startingOffset; + hc4->dictLimit = (U32) startingOffset; + hc4->lowLimit = (U32) startingOffset; +} + + +/* Update chains up to ip (excluded) */ +LZ4_FORCE_INLINE void LZ4HC_Insert (LZ4HC_CCtx_internal* hc4, const BYTE* ip) +{ + U16* const chainTable = hc4->chainTable; + U32* const hashTable = hc4->hashTable; + const BYTE* const base = hc4->base; + U32 const target = (U32)(ip - base); + U32 idx = hc4->nextToUpdate; + + while (idx < target) { + U32 const h = LZ4HC_hashPtr(base+idx); + size_t delta = idx - hashTable[h]; + if (delta>LZ4_DISTANCE_MAX) delta = LZ4_DISTANCE_MAX; + DELTANEXTU16(chainTable, idx) = (U16)delta; + hashTable[h] = idx; + idx++; + } + + hc4->nextToUpdate = target; +} + +/** LZ4HC_countBack() : + * @return : negative value, nb of common bytes before ip/match */ +LZ4_FORCE_INLINE +int LZ4HC_countBack(const BYTE* const ip, const BYTE* const match, + const BYTE* const iMin, const BYTE* const mMin) +{ + int back = 0; + int const min = (int)MAX(iMin - ip, mMin - match); + assert(min <= 0); + assert(ip >= iMin); assert((size_t)(ip-iMin) < (1U<<31)); + assert(match >= mMin); assert((size_t)(match - mMin) < (1U<<31)); + while ( (back > min) + && (ip[back-1] == match[back-1]) ) + back--; + return back; +} + +#if defined(_MSC_VER) +# define LZ4HC_rotl32(x,r) _rotl(x,r) +#else +# define LZ4HC_rotl32(x,r) ((x << r) | (x >> (32 - r))) +#endif + + +static U32 LZ4HC_rotatePattern(size_t const rotate, U32 const pattern) +{ + size_t const bitsToRotate = (rotate & (sizeof(pattern) - 1)) << 3; + if (bitsToRotate == 0) + return pattern; + return LZ4HC_rotl32(pattern, (int)bitsToRotate); +} + +/* LZ4HC_countPattern() : + * pattern32 must be a sample of repetitive pattern of length 1, 2 or 4 (but not 3!) */ +static unsigned +LZ4HC_countPattern(const BYTE* ip, const BYTE* const iEnd, U32 const pattern32) +{ + const BYTE* const iStart = ip; + reg_t const pattern = (sizeof(pattern)==8) ? (reg_t)pattern32 + (((reg_t)pattern32) << 32) : pattern32; + + while (likely(ip < iEnd-(sizeof(pattern)-1))) { + reg_t const diff = LZ4_read_ARCH(ip) ^ pattern; + if (!diff) { ip+=sizeof(pattern); continue; } + ip += LZ4_NbCommonBytes(diff); + return (unsigned)(ip - iStart); + } + + if (LZ4_isLittleEndian()) { + reg_t patternByte = pattern; + while ((ip<iEnd) && (*ip == (BYTE)patternByte)) { + ip++; patternByte >>= 8; + } + } else { /* big endian */ + U32 bitOffset = (sizeof(pattern)*8) - 8; + while (ip < iEnd) { + BYTE const byte = (BYTE)(pattern >> bitOffset); + if (*ip != byte) break; + ip ++; bitOffset -= 8; + } + } + + return (unsigned)(ip - iStart); +} + +/* LZ4HC_reverseCountPattern() : + * pattern must be a sample of repetitive pattern of length 1, 2 or 4 (but not 3!) + * read using natural platform endianess */ +static unsigned +LZ4HC_reverseCountPattern(const BYTE* ip, const BYTE* const iLow, U32 pattern) +{ + const BYTE* const iStart = ip; + + while (likely(ip >= iLow+4)) { + if (LZ4_read32(ip-4) != pattern) break; + ip -= 4; + } + { const BYTE* bytePtr = (const BYTE*)(&pattern) + 3; /* works for any endianess */ + while (likely(ip>iLow)) { + if (ip[-1] != *bytePtr) break; + ip--; bytePtr--; + } } + return (unsigned)(iStart - ip); +} + +/* LZ4HC_protectDictEnd() : + * Checks if the match is in the last 3 bytes of the dictionary, so reading the + * 4 byte MINMATCH would overflow. + * @returns true if the match index is okay. + */ +static int LZ4HC_protectDictEnd(U32 const dictLimit, U32 const matchIndex) +{ + return ((U32)((dictLimit - 1) - matchIndex) >= 3); +} + +typedef enum { rep_untested, rep_not, rep_confirmed } repeat_state_e; +typedef enum { favorCompressionRatio=0, favorDecompressionSpeed } HCfavor_e; + +LZ4_FORCE_INLINE int +LZ4HC_InsertAndGetWiderMatch ( + LZ4HC_CCtx_internal* hc4, + const BYTE* const ip, + const BYTE* const iLowLimit, + const BYTE* const iHighLimit, + int longest, + const BYTE** matchpos, + const BYTE** startpos, + const int maxNbAttempts, + const int patternAnalysis, + const int chainSwap, + const dictCtx_directive dict, + const HCfavor_e favorDecSpeed) +{ + U16* const chainTable = hc4->chainTable; + U32* const HashTable = hc4->hashTable; + const LZ4HC_CCtx_internal * const dictCtx = hc4->dictCtx; + const BYTE* const base = hc4->base; + const U32 dictLimit = hc4->dictLimit; + const BYTE* const lowPrefixPtr = base + dictLimit; + const U32 ipIndex = (U32)(ip - base); + const U32 lowestMatchIndex = (hc4->lowLimit + (LZ4_DISTANCE_MAX + 1) > ipIndex) ? hc4->lowLimit : ipIndex - LZ4_DISTANCE_MAX; + const BYTE* const dictBase = hc4->dictBase; + int const lookBackLength = (int)(ip-iLowLimit); + int nbAttempts = maxNbAttempts; + U32 matchChainPos = 0; + U32 const pattern = LZ4_read32(ip); + U32 matchIndex; + repeat_state_e repeat = rep_untested; + size_t srcPatternLength = 0; + + DEBUGLOG(7, "LZ4HC_InsertAndGetWiderMatch"); + /* First Match */ + LZ4HC_Insert(hc4, ip); + matchIndex = HashTable[LZ4HC_hashPtr(ip)]; + DEBUGLOG(7, "First match at index %u / %u (lowestMatchIndex)", + matchIndex, lowestMatchIndex); + + while ((matchIndex>=lowestMatchIndex) && (nbAttempts)) { + int matchLength=0; + nbAttempts--; + assert(matchIndex < ipIndex); + if (favorDecSpeed && (ipIndex - matchIndex < 8)) { + /* do nothing */ + } else if (matchIndex >= dictLimit) { /* within current Prefix */ + const BYTE* const matchPtr = base + matchIndex; + assert(matchPtr >= lowPrefixPtr); + assert(matchPtr < ip); + assert(longest >= 1); + if (LZ4_read16(iLowLimit + longest - 1) == LZ4_read16(matchPtr - lookBackLength + longest - 1)) { + if (LZ4_read32(matchPtr) == pattern) { + int const back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, lowPrefixPtr) : 0; + matchLength = MINMATCH + (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit); + matchLength -= back; + if (matchLength > longest) { + longest = matchLength; + *matchpos = matchPtr + back; + *startpos = ip + back; + } } } + } else { /* lowestMatchIndex <= matchIndex < dictLimit */ + const BYTE* const matchPtr = dictBase + matchIndex; + if (LZ4_read32(matchPtr) == pattern) { + const BYTE* const dictStart = dictBase + hc4->lowLimit; + int back = 0; + const BYTE* vLimit = ip + (dictLimit - matchIndex); + if (vLimit > iHighLimit) vLimit = iHighLimit; + matchLength = (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH; + if ((ip+matchLength == vLimit) && (vLimit < iHighLimit)) + matchLength += LZ4_count(ip+matchLength, lowPrefixPtr, iHighLimit); + back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictStart) : 0; + matchLength -= back; + if (matchLength > longest) { + longest = matchLength; + *matchpos = base + matchIndex + back; /* virtual pos, relative to ip, to retrieve offset */ + *startpos = ip + back; + } } } + + if (chainSwap && matchLength==longest) { /* better match => select a better chain */ + assert(lookBackLength==0); /* search forward only */ + if (matchIndex + (U32)longest <= ipIndex) { + int const kTrigger = 4; + U32 distanceToNextMatch = 1; + int const end = longest - MINMATCH + 1; + int step = 1; + int accel = 1 << kTrigger; + int pos; + for (pos = 0; pos < end; pos += step) { + U32 const candidateDist = DELTANEXTU16(chainTable, matchIndex + (U32)pos); + step = (accel++ >> kTrigger); + if (candidateDist > distanceToNextMatch) { + distanceToNextMatch = candidateDist; + matchChainPos = (U32)pos; + accel = 1 << kTrigger; + } + } + if (distanceToNextMatch > 1) { + if (distanceToNextMatch > matchIndex) break; /* avoid overflow */ + matchIndex -= distanceToNextMatch; + continue; + } } } + + { U32 const distNextMatch = DELTANEXTU16(chainTable, matchIndex); + if (patternAnalysis && distNextMatch==1 && matchChainPos==0) { + U32 const matchCandidateIdx = matchIndex-1; + /* may be a repeated pattern */ + if (repeat == rep_untested) { + if ( ((pattern & 0xFFFF) == (pattern >> 16)) + & ((pattern & 0xFF) == (pattern >> 24)) ) { + repeat = rep_confirmed; + srcPatternLength = LZ4HC_countPattern(ip+sizeof(pattern), iHighLimit, pattern) + sizeof(pattern); + } else { + repeat = rep_not; + } } + if ( (repeat == rep_confirmed) && (matchCandidateIdx >= lowestMatchIndex) + && LZ4HC_protectDictEnd(dictLimit, matchCandidateIdx) ) { + const int extDict = matchCandidateIdx < dictLimit; + const BYTE* const matchPtr = (extDict ? dictBase : base) + matchCandidateIdx; + if (LZ4_read32(matchPtr) == pattern) { /* good candidate */ + const BYTE* const dictStart = dictBase + hc4->lowLimit; + const BYTE* const iLimit = extDict ? dictBase + dictLimit : iHighLimit; + size_t forwardPatternLength = LZ4HC_countPattern(matchPtr+sizeof(pattern), iLimit, pattern) + sizeof(pattern); + if (extDict && matchPtr + forwardPatternLength == iLimit) { + U32 const rotatedPattern = LZ4HC_rotatePattern(forwardPatternLength, pattern); + forwardPatternLength += LZ4HC_countPattern(lowPrefixPtr, iHighLimit, rotatedPattern); + } + { const BYTE* const lowestMatchPtr = extDict ? dictStart : lowPrefixPtr; + size_t backLength = LZ4HC_reverseCountPattern(matchPtr, lowestMatchPtr, pattern); + size_t currentSegmentLength; + if (!extDict && matchPtr - backLength == lowPrefixPtr && hc4->lowLimit < dictLimit) { + U32 const rotatedPattern = LZ4HC_rotatePattern((U32)(-(int)backLength), pattern); + backLength += LZ4HC_reverseCountPattern(dictBase + dictLimit, dictStart, rotatedPattern); + } + /* Limit backLength not go further than lowestMatchIndex */ + backLength = matchCandidateIdx - MAX(matchCandidateIdx - (U32)backLength, lowestMatchIndex); + assert(matchCandidateIdx - backLength >= lowestMatchIndex); + currentSegmentLength = backLength + forwardPatternLength; + /* Adjust to end of pattern if the source pattern fits, otherwise the beginning of the pattern */ + if ( (currentSegmentLength >= srcPatternLength) /* current pattern segment large enough to contain full srcPatternLength */ + && (forwardPatternLength <= srcPatternLength) ) { /* haven't reached this position yet */ + U32 const newMatchIndex = matchCandidateIdx + (U32)forwardPatternLength - (U32)srcPatternLength; /* best position, full pattern, might be followed by more match */ + if (LZ4HC_protectDictEnd(dictLimit, newMatchIndex)) + matchIndex = newMatchIndex; + else { + /* Can only happen if started in the prefix */ + assert(newMatchIndex >= dictLimit - 3 && newMatchIndex < dictLimit && !extDict); + matchIndex = dictLimit; + } + } else { + U32 const newMatchIndex = matchCandidateIdx - (U32)backLength; /* farthest position in current segment, will find a match of length currentSegmentLength + maybe some back */ + if (!LZ4HC_protectDictEnd(dictLimit, newMatchIndex)) { + assert(newMatchIndex >= dictLimit - 3 && newMatchIndex < dictLimit && !extDict); + matchIndex = dictLimit; + } else { + matchIndex = newMatchIndex; + if (lookBackLength==0) { /* no back possible */ + size_t const maxML = MIN(currentSegmentLength, srcPatternLength); + if ((size_t)longest < maxML) { + assert(base + matchIndex < ip); + if (ip - (base+matchIndex) > LZ4_DISTANCE_MAX) break; + assert(maxML < 2 GB); + longest = (int)maxML; + *matchpos = base + matchIndex; /* virtual pos, relative to ip, to retrieve offset */ + *startpos = ip; + } + { U32 const distToNextPattern = DELTANEXTU16(chainTable, matchIndex); + if (distToNextPattern > matchIndex) break; /* avoid overflow */ + matchIndex -= distToNextPattern; + } } } } } + continue; + } } + } } /* PA optimization */ + + /* follow current chain */ + matchIndex -= DELTANEXTU16(chainTable, matchIndex + matchChainPos); + + } /* while ((matchIndex>=lowestMatchIndex) && (nbAttempts)) */ + + if ( dict == usingDictCtxHc + && nbAttempts + && ipIndex - lowestMatchIndex < LZ4_DISTANCE_MAX) { + size_t const dictEndOffset = (size_t)(dictCtx->end - dictCtx->base); + U32 dictMatchIndex = dictCtx->hashTable[LZ4HC_hashPtr(ip)]; + assert(dictEndOffset <= 1 GB); + matchIndex = dictMatchIndex + lowestMatchIndex - (U32)dictEndOffset; + while (ipIndex - matchIndex <= LZ4_DISTANCE_MAX && nbAttempts--) { + const BYTE* const matchPtr = dictCtx->base + dictMatchIndex; + + if (LZ4_read32(matchPtr) == pattern) { + int mlt; + int back = 0; + const BYTE* vLimit = ip + (dictEndOffset - dictMatchIndex); + if (vLimit > iHighLimit) vLimit = iHighLimit; + mlt = (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH; + back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictCtx->base + dictCtx->dictLimit) : 0; + mlt -= back; + if (mlt > longest) { + longest = mlt; + *matchpos = base + matchIndex + back; + *startpos = ip + back; + } } + + { U32 const nextOffset = DELTANEXTU16(dictCtx->chainTable, dictMatchIndex); + dictMatchIndex -= nextOffset; + matchIndex -= nextOffset; + } } } + + return longest; +} + +LZ4_FORCE_INLINE +int LZ4HC_InsertAndFindBestMatch(LZ4HC_CCtx_internal* const hc4, /* Index table will be updated */ + const BYTE* const ip, const BYTE* const iLimit, + const BYTE** matchpos, + const int maxNbAttempts, + const int patternAnalysis, + const dictCtx_directive dict) +{ + const BYTE* uselessPtr = ip; + /* note : LZ4HC_InsertAndGetWiderMatch() is able to modify the starting position of a match (*startpos), + * but this won't be the case here, as we define iLowLimit==ip, + * so LZ4HC_InsertAndGetWiderMatch() won't be allowed to search past ip */ + return LZ4HC_InsertAndGetWiderMatch(hc4, ip, ip, iLimit, MINMATCH-1, matchpos, &uselessPtr, maxNbAttempts, patternAnalysis, 0 /*chainSwap*/, dict, favorCompressionRatio); +} + +/* LZ4HC_encodeSequence() : + * @return : 0 if ok, + * 1 if buffer issue detected */ +LZ4_FORCE_INLINE int LZ4HC_encodeSequence ( + const BYTE** ip, + BYTE** op, + const BYTE** anchor, + int matchLength, + const BYTE* const match, + limitedOutput_directive limit, + BYTE* oend) +{ + size_t length; + BYTE* const token = (*op)++; + +#if defined(LZ4_DEBUG) && (LZ4_DEBUG >= 6) + static const BYTE* start = NULL; + static U32 totalCost = 0; + U32 const pos = (start==NULL) ? 0 : (U32)(*anchor - start); + U32 const ll = (U32)(*ip - *anchor); + U32 const llAdd = (ll>=15) ? ((ll-15) / 255) + 1 : 0; + U32 const mlAdd = (matchLength>=19) ? ((matchLength-19) / 255) + 1 : 0; + U32 const cost = 1 + llAdd + ll + 2 + mlAdd; + if (start==NULL) start = *anchor; /* only works for single segment */ + /* g_debuglog_enable = (pos >= 2228) & (pos <= 2262); */ + DEBUGLOG(6, "pos:%7u -- literals:%3u, match:%4i, offset:%5u, cost:%3u + %u", + pos, + (U32)(*ip - *anchor), matchLength, (U32)(*ip-match), + cost, totalCost); + totalCost += cost; +#endif + + /* Encode Literal length */ + length = (size_t)(*ip - *anchor); + if ((limit) && ((*op + (length / 255) + length + (2 + 1 + LASTLITERALS)) > oend)) return 1; /* Check output limit */ + if (length >= RUN_MASK) { + size_t len = length - RUN_MASK; + *token = (RUN_MASK << ML_BITS); + for(; len >= 255 ; len -= 255) *(*op)++ = 255; + *(*op)++ = (BYTE)len; + } else { + *token = (BYTE)(length << ML_BITS); + } + + /* Copy Literals */ + LZ4_wildCopy8(*op, *anchor, (*op) + length); + *op += length; + + /* Encode Offset */ + assert( (*ip - match) <= LZ4_DISTANCE_MAX ); /* note : consider providing offset as a value, rather than as a pointer difference */ + LZ4_writeLE16(*op, (U16)(*ip-match)); *op += 2; + + /* Encode MatchLength */ + assert(matchLength >= MINMATCH); + length = (size_t)matchLength - MINMATCH; + if ((limit) && (*op + (length / 255) + (1 + LASTLITERALS) > oend)) return 1; /* Check output limit */ + if (length >= ML_MASK) { + *token += ML_MASK; + length -= ML_MASK; + for(; length >= 510 ; length -= 510) { *(*op)++ = 255; *(*op)++ = 255; } + if (length >= 255) { length -= 255; *(*op)++ = 255; } + *(*op)++ = (BYTE)length; + } else { + *token += (BYTE)(length); + } + + /* Prepare next loop */ + *ip += matchLength; + *anchor = *ip; + + return 0; +} + +LZ4_FORCE_INLINE int LZ4HC_compress_hashChain ( + LZ4HC_CCtx_internal* const ctx, + const char* const source, + char* const dest, + int* srcSizePtr, + int const maxOutputSize, + unsigned maxNbAttempts, + const limitedOutput_directive limit, + const dictCtx_directive dict + ) +{ + const int inputSize = *srcSizePtr; + const int patternAnalysis = (maxNbAttempts > 128); /* levels 9+ */ + + const BYTE* ip = (const BYTE*) source; + const BYTE* anchor = ip; + const BYTE* const iend = ip + inputSize; + const BYTE* const mflimit = iend - MFLIMIT; + const BYTE* const matchlimit = (iend - LASTLITERALS); + + BYTE* optr = (BYTE*) dest; + BYTE* op = (BYTE*) dest; + BYTE* oend = op + maxOutputSize; + + int ml0, ml, ml2, ml3; + const BYTE* start0; + const BYTE* ref0; + const BYTE* ref = NULL; + const BYTE* start2 = NULL; + const BYTE* ref2 = NULL; + const BYTE* start3 = NULL; + const BYTE* ref3 = NULL; + + /* init */ + *srcSizePtr = 0; + if (limit == fillOutput) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */ + if (inputSize < LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */ + + /* Main Loop */ + while (ip <= mflimit) { + ml = LZ4HC_InsertAndFindBestMatch(ctx, ip, matchlimit, &ref, maxNbAttempts, patternAnalysis, dict); + if (ml<MINMATCH) { ip++; continue; } + + /* saved, in case we would skip too much */ + start0 = ip; ref0 = ref; ml0 = ml; + +_Search2: + if (ip+ml <= mflimit) { + ml2 = LZ4HC_InsertAndGetWiderMatch(ctx, + ip + ml - 2, ip + 0, matchlimit, ml, &ref2, &start2, + maxNbAttempts, patternAnalysis, 0, dict, favorCompressionRatio); + } else { + ml2 = ml; + } + + if (ml2 == ml) { /* No better match => encode ML1 */ + optr = op; + if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow; + continue; + } + + if (start0 < ip) { /* first match was skipped at least once */ + if (start2 < ip + ml0) { /* squeezing ML1 between ML0(original ML1) and ML2 */ + ip = start0; ref = ref0; ml = ml0; /* restore initial ML1 */ + } } + + /* Here, start0==ip */ + if ((start2 - ip) < 3) { /* First Match too small : removed */ + ml = ml2; + ip = start2; + ref =ref2; + goto _Search2; + } + +_Search3: + /* At this stage, we have : + * ml2 > ml1, and + * ip1+3 <= ip2 (usually < ip1+ml1) */ + if ((start2 - ip) < OPTIMAL_ML) { + int correction; + int new_ml = ml; + if (new_ml > OPTIMAL_ML) new_ml = OPTIMAL_ML; + if (ip+new_ml > start2 + ml2 - MINMATCH) new_ml = (int)(start2 - ip) + ml2 - MINMATCH; + correction = new_ml - (int)(start2 - ip); + if (correction > 0) { + start2 += correction; + ref2 += correction; + ml2 -= correction; + } + } + /* Now, we have start2 = ip+new_ml, with new_ml = min(ml, OPTIMAL_ML=18) */ + + if (start2 + ml2 <= mflimit) { + ml3 = LZ4HC_InsertAndGetWiderMatch(ctx, + start2 + ml2 - 3, start2, matchlimit, ml2, &ref3, &start3, + maxNbAttempts, patternAnalysis, 0, dict, favorCompressionRatio); + } else { + ml3 = ml2; + } + + if (ml3 == ml2) { /* No better match => encode ML1 and ML2 */ + /* ip & ref are known; Now for ml */ + if (start2 < ip+ml) ml = (int)(start2 - ip); + /* Now, encode 2 sequences */ + optr = op; + if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow; + ip = start2; + optr = op; + if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml2, ref2, limit, oend)) goto _dest_overflow; + continue; + } + + if (start3 < ip+ml+3) { /* Not enough space for match 2 : remove it */ + if (start3 >= (ip+ml)) { /* can write Seq1 immediately ==> Seq2 is removed, so Seq3 becomes Seq1 */ + if (start2 < ip+ml) { + int correction = (int)(ip+ml - start2); + start2 += correction; + ref2 += correction; + ml2 -= correction; + if (ml2 < MINMATCH) { + start2 = start3; + ref2 = ref3; + ml2 = ml3; + } + } + + optr = op; + if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow; + ip = start3; + ref = ref3; + ml = ml3; + + start0 = start2; + ref0 = ref2; + ml0 = ml2; + goto _Search2; + } + + start2 = start3; + ref2 = ref3; + ml2 = ml3; + goto _Search3; + } + + /* + * OK, now we have 3 ascending matches; + * let's write the first one ML1. + * ip & ref are known; Now decide ml. + */ + if (start2 < ip+ml) { + if ((start2 - ip) < OPTIMAL_ML) { + int correction; + if (ml > OPTIMAL_ML) ml = OPTIMAL_ML; + if (ip + ml > start2 + ml2 - MINMATCH) ml = (int)(start2 - ip) + ml2 - MINMATCH; + correction = ml - (int)(start2 - ip); + if (correction > 0) { + start2 += correction; + ref2 += correction; + ml2 -= correction; + } + } else { + ml = (int)(start2 - ip); + } + } + optr = op; + if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow; + + /* ML2 becomes ML1 */ + ip = start2; ref = ref2; ml = ml2; + + /* ML3 becomes ML2 */ + start2 = start3; ref2 = ref3; ml2 = ml3; + + /* let's find a new ML3 */ + goto _Search3; + } + +_last_literals: + /* Encode Last Literals */ + { size_t lastRunSize = (size_t)(iend - anchor); /* literals */ + size_t litLength = (lastRunSize + 255 - RUN_MASK) / 255; + size_t const totalSize = 1 + litLength + lastRunSize; + if (limit == fillOutput) oend += LASTLITERALS; /* restore correct value */ + if (limit && (op + totalSize > oend)) { + if (limit == limitedOutput) return 0; /* Check output limit */ + /* adapt lastRunSize to fill 'dest' */ + lastRunSize = (size_t)(oend - op) - 1; + litLength = (lastRunSize + 255 - RUN_MASK) / 255; + lastRunSize -= litLength; + } + ip = anchor + lastRunSize; + + if (lastRunSize >= RUN_MASK) { + size_t accumulator = lastRunSize - RUN_MASK; + *op++ = (RUN_MASK << ML_BITS); + for(; accumulator >= 255 ; accumulator -= 255) *op++ = 255; + *op++ = (BYTE) accumulator; + } else { + *op++ = (BYTE)(lastRunSize << ML_BITS); + } + memcpy(op, anchor, lastRunSize); + op += lastRunSize; + } + + /* End */ + *srcSizePtr = (int) (((const char*)ip) - source); + return (int) (((char*)op)-dest); + +_dest_overflow: + if (limit == fillOutput) { + op = optr; /* restore correct out pointer */ + goto _last_literals; + } + return 0; +} + + +static int LZ4HC_compress_optimal( LZ4HC_CCtx_internal* ctx, + const char* const source, char* dst, + int* srcSizePtr, int dstCapacity, + int const nbSearches, size_t sufficient_len, + const limitedOutput_directive limit, int const fullUpdate, + const dictCtx_directive dict, + HCfavor_e favorDecSpeed); + + +LZ4_FORCE_INLINE int LZ4HC_compress_generic_internal ( + LZ4HC_CCtx_internal* const ctx, + const char* const src, + char* const dst, + int* const srcSizePtr, + int const dstCapacity, + int cLevel, + const limitedOutput_directive limit, + const dictCtx_directive dict + ) +{ + typedef enum { lz4hc, lz4opt } lz4hc_strat_e; + typedef struct { + lz4hc_strat_e strat; + U32 nbSearches; + U32 targetLength; + } cParams_t; + static const cParams_t clTable[LZ4HC_CLEVEL_MAX+1] = { + { lz4hc, 2, 16 }, /* 0, unused */ + { lz4hc, 2, 16 }, /* 1, unused */ + { lz4hc, 2, 16 }, /* 2, unused */ + { lz4hc, 4, 16 }, /* 3 */ + { lz4hc, 8, 16 }, /* 4 */ + { lz4hc, 16, 16 }, /* 5 */ + { lz4hc, 32, 16 }, /* 6 */ + { lz4hc, 64, 16 }, /* 7 */ + { lz4hc, 128, 16 }, /* 8 */ + { lz4hc, 256, 16 }, /* 9 */ + { lz4opt, 96, 64 }, /*10==LZ4HC_CLEVEL_OPT_MIN*/ + { lz4opt, 512,128 }, /*11 */ + { lz4opt,16384,LZ4_OPT_NUM }, /* 12==LZ4HC_CLEVEL_MAX */ + }; + + DEBUGLOG(4, "LZ4HC_compress_generic(ctx=%p, src=%p, srcSize=%d)", ctx, src, *srcSizePtr); + + if (limit == fillOutput && dstCapacity < 1) return 0; /* Impossible to store anything */ + if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size (too large or negative) */ + + ctx->end += *srcSizePtr; + if (cLevel < 1) cLevel = LZ4HC_CLEVEL_DEFAULT; /* note : convention is different from lz4frame, maybe something to review */ + cLevel = MIN(LZ4HC_CLEVEL_MAX, cLevel); + { cParams_t const cParam = clTable[cLevel]; + HCfavor_e const favor = ctx->favorDecSpeed ? favorDecompressionSpeed : favorCompressionRatio; + int result; + + if (cParam.strat == lz4hc) { + result = LZ4HC_compress_hashChain(ctx, + src, dst, srcSizePtr, dstCapacity, + cParam.nbSearches, limit, dict); + } else { + assert(cParam.strat == lz4opt); + result = LZ4HC_compress_optimal(ctx, + src, dst, srcSizePtr, dstCapacity, + (int)cParam.nbSearches, cParam.targetLength, limit, + cLevel == LZ4HC_CLEVEL_MAX, /* ultra mode */ + dict, favor); + } + if (result <= 0) ctx->dirty = 1; + return result; + } +} + +static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* ctxPtr, const BYTE* newBlock); + +static int +LZ4HC_compress_generic_noDictCtx ( + LZ4HC_CCtx_internal* const ctx, + const char* const src, + char* const dst, + int* const srcSizePtr, + int const dstCapacity, + int cLevel, + limitedOutput_directive limit + ) +{ + assert(ctx->dictCtx == NULL); + return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, noDictCtx); +} + +static int +LZ4HC_compress_generic_dictCtx ( + LZ4HC_CCtx_internal* const ctx, + const char* const src, + char* const dst, + int* const srcSizePtr, + int const dstCapacity, + int cLevel, + limitedOutput_directive limit + ) +{ + const size_t position = (size_t)(ctx->end - ctx->base) - ctx->lowLimit; + assert(ctx->dictCtx != NULL); + if (position >= 64 KB) { + ctx->dictCtx = NULL; + return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit); + } else if (position == 0 && *srcSizePtr > 4 KB) { + memcpy(ctx, ctx->dictCtx, sizeof(LZ4HC_CCtx_internal)); + LZ4HC_setExternalDict(ctx, (const BYTE *)src); + ctx->compressionLevel = (short)cLevel; + return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit); + } else { + return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, usingDictCtxHc); + } +} + +static int +LZ4HC_compress_generic ( + LZ4HC_CCtx_internal* const ctx, + const char* const src, + char* const dst, + int* const srcSizePtr, + int const dstCapacity, + int cLevel, + limitedOutput_directive limit + ) +{ + if (ctx->dictCtx == NULL) { + return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit); + } else { + return LZ4HC_compress_generic_dictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit); + } +} + + +int LZ4_sizeofStateHC(void) { return (int)sizeof(LZ4_streamHC_t); } + +#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_streamHC_t on 4 bytes. */ +static size_t LZ4_streamHC_t_alignment(void) +{ + struct { char c; LZ4_streamHC_t t; } t_a; + return sizeof(t_a) - sizeof(t_a.t); +} +#endif + +/* state is presumed correctly initialized, + * in which case its size and alignment have already been validate */ +static int LZ4_compress_HC_extStateHC_fastReset (void* state, const char* src, char* dst, int srcSize, + int dstCapacity, int compressionLevel) +{ + LZ4HC_CCtx_internal* const ctx = &((LZ4_streamHC_t*)state)->internal_donotuse; +#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_streamHC_t on 4 bytes. */ + assert(((size_t)state & (LZ4_streamHC_t_alignment() - 1)) == 0); /* check alignment */ +#endif + if (((size_t)(state)&(sizeof(void*)-1)) != 0) return 0; /* Error : state is not aligned for pointers (32 or 64 bits) */ + LZ4_resetStreamHC_fast((LZ4_streamHC_t*)state, compressionLevel); + LZ4HC_init_internal (ctx, (const BYTE*)src); + if (dstCapacity < LZ4_compressBound(srcSize)) + return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, limitedOutput); + else + return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, notLimited); +} + +int LZ4_compress_HC_extStateHC (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel) +{ + LZ4_streamHC_t* const ctx = LZ4_initStreamHC(state, sizeof(*ctx)); + if (ctx==NULL) return 0; /* init failure */ + return LZ4_compress_HC_extStateHC_fastReset(state, src, dst, srcSize, dstCapacity, compressionLevel); +} + +int LZ4_compress_HC(const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel) +{ +#if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1 + LZ4_streamHC_t* const statePtr = (LZ4_streamHC_t*)ALLOC(sizeof(LZ4_streamHC_t)); +#else + LZ4_streamHC_t state; + LZ4_streamHC_t* const statePtr = &state; +#endif + int const cSize = LZ4_compress_HC_extStateHC(statePtr, src, dst, srcSize, dstCapacity, compressionLevel); +#if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1 + FREEMEM(statePtr); +#endif + return cSize; +} + +/* state is presumed sized correctly (>= sizeof(LZ4_streamHC_t)) */ +int LZ4_compress_HC_destSize(void* state, const char* source, char* dest, int* sourceSizePtr, int targetDestSize, int cLevel) +{ + LZ4_streamHC_t* const ctx = LZ4_initStreamHC(state, sizeof(*ctx)); + if (ctx==NULL) return 0; /* init failure */ + LZ4HC_init_internal(&ctx->internal_donotuse, (const BYTE*) source); + LZ4_setCompressionLevel(ctx, cLevel); + return LZ4HC_compress_generic(&ctx->internal_donotuse, source, dest, sourceSizePtr, targetDestSize, cLevel, fillOutput); +} + + + +/************************************** +* Streaming Functions +**************************************/ + +LZ4_streamHC_t* LZ4_initStreamHC (void* buffer, size_t size) +{ + LZ4_streamHC_t* const LZ4_streamHCPtr = (LZ4_streamHC_t*)buffer; + if (buffer == NULL) return NULL; + if (size < sizeof(LZ4_streamHC_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_streamHC_t on 4 bytes. */ + if (((size_t)buffer) & (LZ4_streamHC_t_alignment() - 1)) return NULL; /* alignment check */ +#endif + /* if compilation fails here, LZ4_STREAMHCSIZE must be increased */ + LZ4_STATIC_ASSERT(sizeof(LZ4HC_CCtx_internal) <= LZ4_STREAMHCSIZE); + DEBUGLOG(4, "LZ4_initStreamHC(%p, %u)", LZ4_streamHCPtr, (unsigned)size); + /* end-base will trigger a clearTable on starting compression */ + LZ4_streamHCPtr->internal_donotuse.end = (const BYTE *)(ptrdiff_t)-1; + LZ4_streamHCPtr->internal_donotuse.base = NULL; + LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL; + LZ4_streamHCPtr->internal_donotuse.favorDecSpeed = 0; + LZ4_streamHCPtr->internal_donotuse.dirty = 0; + LZ4_setCompressionLevel(LZ4_streamHCPtr, LZ4HC_CLEVEL_DEFAULT); + return LZ4_streamHCPtr; +} + +/* just a stub */ +void LZ4_resetStreamHC_fast (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel) +{ + DEBUGLOG(4, "LZ4_resetStreamHC_fast(%p, %d)", LZ4_streamHCPtr, compressionLevel); + if (LZ4_streamHCPtr->internal_donotuse.dirty) { + LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr)); + } else { + /* preserve end - base : can trigger clearTable's threshold */ + LZ4_streamHCPtr->internal_donotuse.end -= (uptrval)LZ4_streamHCPtr->internal_donotuse.base; + LZ4_streamHCPtr->internal_donotuse.base = NULL; + LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL; + } + LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel); +} + +void LZ4_setCompressionLevel(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel) +{ + DEBUGLOG(5, "LZ4_setCompressionLevel(%p, %d)", LZ4_streamHCPtr, compressionLevel); + if (compressionLevel < 1) compressionLevel = LZ4HC_CLEVEL_DEFAULT; + if (compressionLevel > LZ4HC_CLEVEL_MAX) compressionLevel = LZ4HC_CLEVEL_MAX; + LZ4_streamHCPtr->internal_donotuse.compressionLevel = (short)compressionLevel; +} + +/* compression */ + +static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* ctxPtr, const BYTE* newBlock) +{ + DEBUGLOG(4, "LZ4HC_setExternalDict(%p, %p)", ctxPtr, newBlock); + if (ctxPtr->end >= ctxPtr->base + ctxPtr->dictLimit + 4) + LZ4HC_Insert (ctxPtr, ctxPtr->end-3); /* Referencing remaining dictionary content */ + + /* Only one memory segment for extDict, so any previous extDict is lost at this stage */ + ctxPtr->lowLimit = ctxPtr->dictLimit; + ctxPtr->dictLimit = (U32)(ctxPtr->end - ctxPtr->base); + ctxPtr->dictBase = ctxPtr->base; + ctxPtr->base = newBlock - ctxPtr->dictLimit; + ctxPtr->end = newBlock; + ctxPtr->nextToUpdate = ctxPtr->dictLimit; /* match referencing will resume from there */ + + /* cannot reference an extDict and a dictCtx at the same time */ + ctxPtr->dictCtx = NULL; +} + +/* ================================================ + * LZ4 Optimal parser (levels [LZ4HC_CLEVEL_OPT_MIN - LZ4HC_CLEVEL_MAX]) + * ===============================================*/ +typedef struct { + int price; + int off; + int mlen; + int litlen; +} LZ4HC_optimal_t; + +/* price in bytes */ +LZ4_FORCE_INLINE int LZ4HC_literalsPrice(int const litlen) +{ + int price = litlen; + assert(litlen >= 0); + if (litlen >= (int)RUN_MASK) + price += 1 + ((litlen-(int)RUN_MASK) / 255); + return price; +} + + +/* requires mlen >= MINMATCH */ +LZ4_FORCE_INLINE int LZ4HC_sequencePrice(int litlen, int mlen) +{ + int price = 1 + 2 ; /* token + 16-bit offset */ + assert(litlen >= 0); + assert(mlen >= MINMATCH); + + price += LZ4HC_literalsPrice(litlen); + + if (mlen >= (int)(ML_MASK+MINMATCH)) + price += 1 + ((mlen-(int)(ML_MASK+MINMATCH)) / 255); + + return price; +} + + +typedef struct { + int off; + int len; +} LZ4HC_match_t; + +LZ4_FORCE_INLINE LZ4HC_match_t +LZ4HC_FindLongerMatch(LZ4HC_CCtx_internal* const ctx, + const BYTE* ip, const BYTE* const iHighLimit, + int minLen, int nbSearches, + const dictCtx_directive dict, + const HCfavor_e favorDecSpeed) +{ + LZ4HC_match_t match = { 0 , 0 }; + const BYTE* matchPtr = NULL; + /* note : LZ4HC_InsertAndGetWiderMatch() is able to modify the starting position of a match (*startpos), + * but this won't be the case here, as we define iLowLimit==ip, + * so LZ4HC_InsertAndGetWiderMatch() won't be allowed to search past ip */ + int matchLength = LZ4HC_InsertAndGetWiderMatch(ctx, ip, ip, iHighLimit, minLen, &matchPtr, &ip, nbSearches, 1 /*patternAnalysis*/, 1 /*chainSwap*/, dict, favorDecSpeed); + if (matchLength <= minLen) return match; + if (favorDecSpeed) { + if ((matchLength>18) & (matchLength<=36)) matchLength=18; /* favor shortcut */ + } + match.len = matchLength; + match.off = (int)(ip-matchPtr); + return match; +} + + +static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx, + const char* const source, + char* dst, + int* srcSizePtr, + int dstCapacity, + int const nbSearches, + size_t sufficient_len, + const limitedOutput_directive limit, + int const fullUpdate, + const dictCtx_directive dict, + const HCfavor_e favorDecSpeed) +{ +#define TRAILING_LITERALS 3 + LZ4HC_optimal_t opt[LZ4_OPT_NUM + TRAILING_LITERALS]; /* ~64 KB, which is a bit large for stack... */ + + const BYTE* ip = (const BYTE*) source; + const BYTE* anchor = ip; + const BYTE* const iend = ip + *srcSizePtr; + const BYTE* const mflimit = iend - MFLIMIT; + const BYTE* const matchlimit = iend - LASTLITERALS; + BYTE* op = (BYTE*) dst; + BYTE* opSaved = (BYTE*) dst; + BYTE* oend = op + dstCapacity; + + /* init */ + DEBUGLOG(5, "LZ4HC_compress_optimal(dst=%p, dstCapa=%u)", dst, (unsigned)dstCapacity); + *srcSizePtr = 0; + if (limit == fillOutput) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */ + if (sufficient_len >= LZ4_OPT_NUM) sufficient_len = LZ4_OPT_NUM-1; + + /* Main Loop */ + assert(ip - anchor < LZ4_MAX_INPUT_SIZE); + while (ip <= mflimit) { + int const llen = (int)(ip - anchor); + int best_mlen, best_off; + int cur, last_match_pos = 0; + + LZ4HC_match_t const firstMatch = LZ4HC_FindLongerMatch(ctx, ip, matchlimit, MINMATCH-1, nbSearches, dict, favorDecSpeed); + if (firstMatch.len==0) { ip++; continue; } + + if ((size_t)firstMatch.len > sufficient_len) { + /* good enough solution : immediate encoding */ + int const firstML = firstMatch.len; + const BYTE* const matchPos = ip - firstMatch.off; + opSaved = op; + if ( LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), firstML, matchPos, limit, oend) ) /* updates ip, op and anchor */ + goto _dest_overflow; + continue; + } + + /* set prices for first positions (literals) */ + { int rPos; + for (rPos = 0 ; rPos < MINMATCH ; rPos++) { + int const cost = LZ4HC_literalsPrice(llen + rPos); + opt[rPos].mlen = 1; + opt[rPos].off = 0; + opt[rPos].litlen = llen + rPos; + opt[rPos].price = cost; + DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i) -- initial setup", + rPos, cost, opt[rPos].litlen); + } } + /* set prices using initial match */ + { int mlen = MINMATCH; + int const matchML = firstMatch.len; /* necessarily < sufficient_len < LZ4_OPT_NUM */ + int const offset = firstMatch.off; + assert(matchML < LZ4_OPT_NUM); + for ( ; mlen <= matchML ; mlen++) { + int const cost = LZ4HC_sequencePrice(llen, mlen); + opt[mlen].mlen = mlen; + opt[mlen].off = offset; + opt[mlen].litlen = llen; + opt[mlen].price = cost; + DEBUGLOG(7, "rPos:%3i => price:%3i (matchlen=%i) -- initial setup", + mlen, cost, mlen); + } } + last_match_pos = firstMatch.len; + { int addLit; + for (addLit = 1; addLit <= TRAILING_LITERALS; addLit ++) { + opt[last_match_pos+addLit].mlen = 1; /* literal */ + opt[last_match_pos+addLit].off = 0; + opt[last_match_pos+addLit].litlen = addLit; + opt[last_match_pos+addLit].price = opt[last_match_pos].price + LZ4HC_literalsPrice(addLit); + DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i) -- initial setup", + last_match_pos+addLit, opt[last_match_pos+addLit].price, addLit); + } } + + /* check further positions */ + for (cur = 1; cur < last_match_pos; cur++) { + const BYTE* const curPtr = ip + cur; + LZ4HC_match_t newMatch; + + if (curPtr > mflimit) break; + DEBUGLOG(7, "rPos:%u[%u] vs [%u]%u", + cur, opt[cur].price, opt[cur+1].price, cur+1); + if (fullUpdate) { + /* not useful to search here if next position has same (or lower) cost */ + if ( (opt[cur+1].price <= opt[cur].price) + /* in some cases, next position has same cost, but cost rises sharply after, so a small match would still be beneficial */ + && (opt[cur+MINMATCH].price < opt[cur].price + 3/*min seq price*/) ) + continue; + } else { + /* not useful to search here if next position has same (or lower) cost */ + if (opt[cur+1].price <= opt[cur].price) continue; + } + + DEBUGLOG(7, "search at rPos:%u", cur); + if (fullUpdate) + newMatch = LZ4HC_FindLongerMatch(ctx, curPtr, matchlimit, MINMATCH-1, nbSearches, dict, favorDecSpeed); + else + /* only test matches of minimum length; slightly faster, but misses a few bytes */ + newMatch = LZ4HC_FindLongerMatch(ctx, curPtr, matchlimit, last_match_pos - cur, nbSearches, dict, favorDecSpeed); + if (!newMatch.len) continue; + + if ( ((size_t)newMatch.len > sufficient_len) + || (newMatch.len + cur >= LZ4_OPT_NUM) ) { + /* immediate encoding */ + best_mlen = newMatch.len; + best_off = newMatch.off; + last_match_pos = cur + 1; + goto encode; + } + + /* before match : set price with literals at beginning */ + { int const baseLitlen = opt[cur].litlen; + int litlen; + for (litlen = 1; litlen < MINMATCH; litlen++) { + int const price = opt[cur].price - LZ4HC_literalsPrice(baseLitlen) + LZ4HC_literalsPrice(baseLitlen+litlen); + int const pos = cur + litlen; + if (price < opt[pos].price) { + opt[pos].mlen = 1; /* literal */ + opt[pos].off = 0; + opt[pos].litlen = baseLitlen+litlen; + opt[pos].price = price; + DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i)", + pos, price, opt[pos].litlen); + } } } + + /* set prices using match at position = cur */ + { int const matchML = newMatch.len; + int ml = MINMATCH; + + assert(cur + newMatch.len < LZ4_OPT_NUM); + for ( ; ml <= matchML ; ml++) { + int const pos = cur + ml; + int const offset = newMatch.off; + int price; + int ll; + DEBUGLOG(7, "testing price rPos %i (last_match_pos=%i)", + pos, last_match_pos); + if (opt[cur].mlen == 1) { + ll = opt[cur].litlen; + price = ((cur > ll) ? opt[cur - ll].price : 0) + + LZ4HC_sequencePrice(ll, ml); + } else { + ll = 0; + price = opt[cur].price + LZ4HC_sequencePrice(0, ml); + } + + assert((U32)favorDecSpeed <= 1); + if (pos > last_match_pos+TRAILING_LITERALS + || price <= opt[pos].price - (int)favorDecSpeed) { + DEBUGLOG(7, "rPos:%3i => price:%3i (matchlen=%i)", + pos, price, ml); + assert(pos < LZ4_OPT_NUM); + if ( (ml == matchML) /* last pos of last match */ + && (last_match_pos < pos) ) + last_match_pos = pos; + opt[pos].mlen = ml; + opt[pos].off = offset; + opt[pos].litlen = ll; + opt[pos].price = price; + } } } + /* complete following positions with literals */ + { int addLit; + for (addLit = 1; addLit <= TRAILING_LITERALS; addLit ++) { + opt[last_match_pos+addLit].mlen = 1; /* literal */ + opt[last_match_pos+addLit].off = 0; + opt[last_match_pos+addLit].litlen = addLit; + opt[last_match_pos+addLit].price = opt[last_match_pos].price + LZ4HC_literalsPrice(addLit); + DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i)", last_match_pos+addLit, opt[last_match_pos+addLit].price, addLit); + } } + } /* for (cur = 1; cur <= last_match_pos; cur++) */ + + assert(last_match_pos < LZ4_OPT_NUM + TRAILING_LITERALS); + best_mlen = opt[last_match_pos].mlen; + best_off = opt[last_match_pos].off; + cur = last_match_pos - best_mlen; + + encode: /* cur, last_match_pos, best_mlen, best_off must be set */ + assert(cur < LZ4_OPT_NUM); + assert(last_match_pos >= 1); /* == 1 when only one candidate */ + DEBUGLOG(6, "reverse traversal, looking for shortest path (last_match_pos=%i)", last_match_pos); + { int candidate_pos = cur; + int selected_matchLength = best_mlen; + int selected_offset = best_off; + while (1) { /* from end to beginning */ + int const next_matchLength = opt[candidate_pos].mlen; /* can be 1, means literal */ + int const next_offset = opt[candidate_pos].off; + DEBUGLOG(7, "pos %i: sequence length %i", candidate_pos, selected_matchLength); + opt[candidate_pos].mlen = selected_matchLength; + opt[candidate_pos].off = selected_offset; + selected_matchLength = next_matchLength; + selected_offset = next_offset; + if (next_matchLength > candidate_pos) break; /* last match elected, first match to encode */ + assert(next_matchLength > 0); /* can be 1, means literal */ + candidate_pos -= next_matchLength; + } } + + /* encode all recorded sequences in order */ + { int rPos = 0; /* relative position (to ip) */ + while (rPos < last_match_pos) { + int const ml = opt[rPos].mlen; + int const offset = opt[rPos].off; + if (ml == 1) { ip++; rPos++; continue; } /* literal; note: can end up with several literals, in which case, skip them */ + rPos += ml; + assert(ml >= MINMATCH); + assert((offset >= 1) && (offset <= LZ4_DISTANCE_MAX)); + opSaved = op; + if ( LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ip - offset, limit, oend) ) /* updates ip, op and anchor */ + goto _dest_overflow; + } } + } /* while (ip <= mflimit) */ + + _last_literals: + /* Encode Last Literals */ + { size_t lastRunSize = (size_t)(iend - anchor); /* literals */ + size_t litLength = (lastRunSize + 255 - RUN_MASK) / 255; + size_t const totalSize = 1 + litLength + lastRunSize; + if (limit == fillOutput) oend += LASTLITERALS; /* restore correct value */ + if (limit && (op + totalSize > oend)) { + if (limit == limitedOutput) return 0; /* Check output limit */ + /* adapt lastRunSize to fill 'dst' */ + lastRunSize = (size_t)(oend - op) - 1; + litLength = (lastRunSize + 255 - RUN_MASK) / 255; + lastRunSize -= litLength; + } + ip = anchor + lastRunSize; + + if (lastRunSize >= RUN_MASK) { + size_t accumulator = lastRunSize - RUN_MASK; + *op++ = (RUN_MASK << ML_BITS); + for(; accumulator >= 255 ; accumulator -= 255) *op++ = 255; + *op++ = (BYTE) accumulator; + } else { + *op++ = (BYTE)(lastRunSize << ML_BITS); + } + memcpy(op, anchor, lastRunSize); + op += lastRunSize; + } + + /* End */ + *srcSizePtr = (int) (((const char*)ip) - source); + return (int) ((char*)op-dst); + + _dest_overflow: + if (limit == fillOutput) { + op = opSaved; /* restore correct out pointer */ + goto _last_literals; + } + return 0; + } diff --git a/lib/lz4/lz4hc.h b/lib/lz4/lz4hc.h new file mode 100644 index 0000000..157d813 --- /dev/null +++ b/lib/lz4/lz4hc.h @@ -0,0 +1,307 @@ +/* + LZ4 HC - High Compression Mode of LZ4 + Header File + Copyright (C) 2011-2017, Yann Collet. + BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are + met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above + copyright notice, this list of conditions and the following disclaimer + in the documentation and/or other materials provided with the + distribution. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + + You can contact the author at : + - LZ4 source repository : https://github.com/lz4/lz4 + - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c +*/ +#ifndef LZ4_HC_H_19834876238432 +#define LZ4_HC_H_19834876238432 + +#if defined (__cplusplus) +extern "C" { +#endif + +/* --- Dependency --- */ +/* note : lz4hc requires lz4.h/lz4.c for compilation */ +#include "lz4.h" /* stddef, LZ4LIB_API, LZ4_DEPRECATED */ + + +/* --- Useful constants --- */ +#define LZ4HC_CLEVEL_MIN 3 +#define LZ4HC_CLEVEL_DEFAULT 9 +#define LZ4HC_CLEVEL_OPT_MIN 10 +#define LZ4HC_CLEVEL_MAX 12 + + +/*-************************************ + * Block Compression + **************************************/ +/*! LZ4_compress_HC() : + * Compress data from `src` into `dst`, using the powerful but slower "HC" algorithm. + * `dst` must be already allocated. + * Compression is guaranteed to succeed if `dstCapacity >= LZ4_compressBound(srcSize)` (see "lz4.h") + * Max supported `srcSize` value is LZ4_MAX_INPUT_SIZE (see "lz4.h") + * `compressionLevel` : any value between 1 and LZ4HC_CLEVEL_MAX will work. + * Values > LZ4HC_CLEVEL_MAX behave the same as LZ4HC_CLEVEL_MAX. + * @return : the number of bytes written into 'dst' + * or 0 if compression fails. + */ +LZ4LIB_API int LZ4_compress_HC (const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel); + + +/* Note : + * Decompression functions are provided within "lz4.h" (BSD license) + */ + + +/*! LZ4_compress_HC_extStateHC() : + * Same as LZ4_compress_HC(), but using an externally allocated memory segment for `state`. + * `state` size is provided by LZ4_sizeofStateHC(). + * Memory segment must be aligned on 8-bytes boundaries (which a normal malloc() should do properly). + */ +LZ4LIB_API int LZ4_sizeofStateHC(void); +LZ4LIB_API int LZ4_compress_HC_extStateHC(void* stateHC, const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel); + + +/*! LZ4_compress_HC_destSize() : v1.9.0+ + * Will compress as much data as possible from `src` + * to fit into `targetDstSize` budget. + * Result is provided in 2 parts : + * @return : the number of bytes written into 'dst' (necessarily <= targetDstSize) + * or 0 if compression fails. + * `srcSizePtr` : on success, *srcSizePtr is updated to indicate how much bytes were read from `src` + */ +LZ4LIB_API int LZ4_compress_HC_destSize(void* stateHC, + const char* src, char* dst, + int* srcSizePtr, int targetDstSize, + int compressionLevel); + + +/*-************************************ + * Streaming Compression + * Bufferless synchronous API + **************************************/ + typedef union LZ4_streamHC_u LZ4_streamHC_t; /* incomplete type (defined later) */ + +/* + These functions compress data in successive blocks of any size, + using previous blocks as dictionary, to improve compression ratio. + One key assumption is that previous blocks (up to 64 KB) remain read-accessible while compressing next blocks. + There is an exception for ring buffers, which can be smaller than 64 KB. + Ring-buffer scenario is automatically detected and handled within LZ4_compress_HC_continue(). + + Before starting compression, state must be allocated and properly initialized. + LZ4_createStreamHC() does both, though compression level is set to LZ4HC_CLEVEL_DEFAULT. + + Selecting the compression level can be done with LZ4_resetStreamHC_fast() (starts a new stream) + or LZ4_setCompressionLevel() (anytime, between blocks in the same stream) (experimental). + LZ4_resetStreamHC_fast() only works on states which have been properly initialized at least once, + which is automatically the case when state is created using LZ4_createStreamHC(). + + After reset, a first "fictional block" can be designated as initial dictionary, + using LZ4_loadDictHC() (Optional). + + Invoke LZ4_compress_HC_continue() to compress each successive block. + The number of blocks is unlimited. + Previous input blocks, including initial dictionary when present, + must remain accessible and unmodified during compression. + + It's allowed to update compression level anytime between blocks, + using LZ4_setCompressionLevel() (experimental). + + 'dst' buffer should be sized to handle worst case scenarios + (see LZ4_compressBound(), it ensures compression success). + In case of failure, the API does not guarantee recovery, + so the state _must_ be reset. + To ensure compression success + whenever `dst` buffer size cannot be made >= LZ4_compressBound(), + consider using LZ4_compress_HC_continue_destSize(). + + Whenever previous input blocks can't be preserved unmodified in-place during compression of next blocks, + it's possible to copy the last blocks into a more stable memory space, using LZ4_saveDictHC(). + Return value of LZ4_saveDictHC() is the size of dictionary effectively saved into 'safeBuffer' (<= 64 KB) + + After completing a streaming compression, + it's possible to start a new stream of blocks, using the same LZ4_streamHC_t state, + just by resetting it, using LZ4_resetStreamHC_fast(). +*/ + +LZ4LIB_API void LZ4_resetStreamHC_fast(LZ4_streamHC_t* streamHCPtr, int compressionLevel); /* v1.9.0+ */ + +/*^********************************************** + * !!!!!! STATIC LINKING ONLY !!!!!! + ***********************************************/ + +/*-****************************************************************** + * PRIVATE DEFINITIONS : + * Do not use these definitions directly. + * They are merely exposed to allow static allocation of `LZ4_streamHC_t`. + * Declare an `LZ4_streamHC_t` directly, rather than any type below. + * Even then, only do so in the context of static linking, as definitions may change between versions. + ********************************************************************/ + +#define LZ4HC_DICTIONARY_LOGSIZE 16 +#define LZ4HC_MAXD (1<<LZ4HC_DICTIONARY_LOGSIZE) +#define LZ4HC_MAXD_MASK (LZ4HC_MAXD - 1) + +#define LZ4HC_HASH_LOG 15 +#define LZ4HC_HASHTABLESIZE (1 << LZ4HC_HASH_LOG) +#define LZ4HC_HASH_MASK (LZ4HC_HASHTABLESIZE - 1) + + +#if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) +#include <stdint.h> + +typedef struct LZ4HC_CCtx_internal LZ4HC_CCtx_internal; +struct LZ4HC_CCtx_internal +{ + uint32_t hashTable[LZ4HC_HASHTABLESIZE]; + uint16_t chainTable[LZ4HC_MAXD]; + const uint8_t* end; /* next block here to continue on current prefix */ + const uint8_t* base; /* All index relative to this position */ + const uint8_t* dictBase; /* alternate base for extDict */ + uint32_t dictLimit; /* below that point, need extDict */ + uint32_t lowLimit; /* below that point, no more dict */ + uint32_t nextToUpdate; /* index from which to continue dictionary update */ + short compressionLevel; + int8_t favorDecSpeed; /* favor decompression speed if this flag set, + otherwise, favor compression ratio */ + int8_t dirty; /* stream has to be fully reset if this flag is set */ + const LZ4HC_CCtx_internal* dictCtx; +}; + +#else + +typedef struct LZ4HC_CCtx_internal LZ4HC_CCtx_internal; +struct LZ4HC_CCtx_internal +{ + unsigned int hashTable[LZ4HC_HASHTABLESIZE]; + unsigned short chainTable[LZ4HC_MAXD]; + const unsigned char* end; /* next block here to continue on current prefix */ + const unsigned char* base; /* All index relative to this position */ + const unsigned char* dictBase; /* alternate base for extDict */ + unsigned int dictLimit; /* below that point, need extDict */ + unsigned int lowLimit; /* below that point, no more dict */ + unsigned int nextToUpdate; /* index from which to continue dictionary update */ + short compressionLevel; + char favorDecSpeed; /* favor decompression speed if this flag set, + otherwise, favor compression ratio */ + char dirty; /* stream has to be fully reset if this flag is set */ + const LZ4HC_CCtx_internal* dictCtx; +}; + +#endif + + +/* Do not use these definitions directly ! + * Declare or allocate an LZ4_streamHC_t instead. + */ +#define LZ4_STREAMHCSIZE (4*LZ4HC_HASHTABLESIZE + 2*LZ4HC_MAXD + 56 + ((sizeof(void*)==16) ? 56 : 0) /* AS400*/ ) /* 262200 or 262256*/ +#define LZ4_STREAMHCSIZE_SIZET (LZ4_STREAMHCSIZE / sizeof(size_t)) +union LZ4_streamHC_u { + size_t table[LZ4_STREAMHCSIZE_SIZET]; + LZ4HC_CCtx_internal internal_donotuse; +}; /* previously typedef'd to LZ4_streamHC_t */ + +/* LZ4_streamHC_t : + * This structure allows static allocation of LZ4 HC streaming state. + * This can be used to allocate statically, on state, or as part of a larger structure. + * + * Such state **must** be initialized using LZ4_initStreamHC() before first use. + * + * Note that invoking LZ4_initStreamHC() is not required when + * the state was created using LZ4_createStreamHC() (which is recommended). + * Using the normal builder, a newly created state is automatically initialized. + * + * Static allocation shall only be used in combination with static linking. + */ + +/* LZ4_initStreamHC() : v1.9.0+ + * Required before first use of a statically allocated LZ4_streamHC_t. + * Before v1.9.0 : use LZ4_resetStreamHC() instead + */ +LZ4LIB_API LZ4_streamHC_t* LZ4_initStreamHC (void* buffer, size_t size); + +#if defined (__cplusplus) +} +#endif + +#endif /* LZ4_HC_H_19834876238432 */ + + +/*-************************************************** + * !!!!! STATIC LINKING ONLY !!!!! + * Following definitions are considered experimental. + * They should not be linked from DLL, + * as there is no guarantee of API stability yet. + * Prototypes will be promoted to "stable" status + * after successfull usage in real-life scenarios. + ***************************************************/ +#ifdef LZ4_HC_STATIC_LINKING_ONLY /* protection macro */ +#ifndef LZ4_HC_SLO_098092834 +#define LZ4_HC_SLO_098092834 + +#define LZ4_STATIC_LINKING_ONLY /* LZ4LIB_STATIC_API */ +#include "lz4.h" + +#if defined (__cplusplus) +extern "C" { +#endif + +/*! LZ4_setCompressionLevel() : v1.8.0+ (experimental) + * It's possible to change compression level + * between successive invocations of LZ4_compress_HC_continue*() + * for dynamic adaptation. + */ +LZ4LIB_STATIC_API void LZ4_setCompressionLevel( + LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel); + +/*! LZ4_resetStreamHC_fast() : v1.9.0+ + * When an LZ4_streamHC_t is known to be in a internally coherent state, + * it can often be prepared for a new compression with almost no work, only + * sometimes falling back to the full, expensive reset that is always required + * when the stream is in an indeterminate state (i.e., the reset performed by + * LZ4_resetStreamHC()). + * + * LZ4_streamHCs are guaranteed to be in a valid state when: + * - returned from LZ4_createStreamHC() + * - reset by LZ4_resetStreamHC() + * - memset(stream, 0, sizeof(LZ4_streamHC_t)) + * - the stream was in a valid state and was reset by LZ4_resetStreamHC_fast() + * - the stream was in a valid state and was then used in any compression call + * that returned success + * - the stream was in an indeterminate state and was used in a compression + * call that fully reset the state (LZ4_compress_HC_extStateHC()) and that + * returned success + * + * Note: + * A stream that was last used in a compression call that returned an error + * may be passed to this function. However, it will be fully reset, which will + * clear any existing history and settings from the context. + */ +LZ4LIB_STATIC_API void LZ4_resetStreamHC_fast( + LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel); + +#if defined (__cplusplus) +} +#endif + +#endif /* LZ4_HC_SLO_098092834 */ +#endif /* LZ4_HC_STATIC_LINKING_ONLY */ |