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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 14:29:10 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 14:29:10 +0000
commit2aa4a82499d4becd2284cdb482213d541b8804dd (patch)
treeb80bf8bf13c3766139fbacc530efd0dd9d54394c /mfbt/lz4/lz4.c
parentInitial commit. (diff)
downloadfirefox-2aa4a82499d4becd2284cdb482213d541b8804dd.tar.xz
firefox-2aa4a82499d4becd2284cdb482213d541b8804dd.zip
Adding upstream version 86.0.1.upstream/86.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'mfbt/lz4/lz4.c')
-rw-r--r--mfbt/lz4/lz4.c2495
1 files changed, 2495 insertions, 0 deletions
diff --git a/mfbt/lz4/lz4.c b/mfbt/lz4/lz4.c
new file mode 100644
index 0000000000..9f5e9bfa08
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+++ b/mfbt/lz4/lz4.c
@@ -0,0 +1,2495 @@
+/*
+ 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
+
+/*
+ * LZ4_ACCELERATION_DEFAULT :
+ * Select "acceleration" for LZ4_compress_fast() when parameter value <= 0
+ */
+#define LZ4_ACCELERATION_DEFAULT 1
+/*
+ * LZ4_ACCELERATION_MAX :
+ * Any "acceleration" value higher than this threshold
+ * get treated as LZ4_ACCELERATION_MAX instead (fix #876)
+ */
+#define LZ4_ACCELERATION_MAX 65537
+
+
+/*-************************************
+* 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 */
+# undef LZ4_FORCE_SW_BITCOUNT /* avoid double def */
+# 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
+**************************************/
+#if defined(_MSC_VER) && (_MSC_VER >= 1400) /* Visual Studio 2005+ */
+# include <intrin.h> /* only present in VS2005+ */
+# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
+#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 and LZ4_FORCE_INLINE
+ * 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 __attribute__((optimize("O2")))
+# undef LZ4_FORCE_INLINE
+# define LZ4_FORCE_INLINE static __inline __attribute__((optimize("O2"),always_inline))
+#else
+# define LZ4_FORCE_O2
+#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
+
+/* Should the alignment test prove unreliable, for some reason,
+ * it can be disabled by setting LZ4_ALIGN_TEST to 0 */
+#ifndef LZ4_ALIGN_TEST /* can be externally provided */
+# define LZ4_ALIGN_TEST 1
+#endif
+
+
+/*-************************************
+* Memory routines
+**************************************/
+#ifdef LZ4_USER_MEMORY_FUNCTIONS
+/* memory management functions can be customized by user project.
+ * Below functions must exist somewhere in the Project
+ * and be available at link time */
+void* LZ4_malloc(size_t s);
+void* LZ4_calloc(size_t n, size_t s);
+void LZ4_free(void* p);
+# define ALLOC(s) LZ4_malloc(s)
+# define ALLOC_AND_ZERO(s) LZ4_calloc(1,s)
+# define FREEMEM(p) LZ4_free(p)
+#else
+# include <stdlib.h> /* malloc, calloc, free */
+# define ALLOC(s) malloc(s)
+# define ALLOC_AND_ZERO(s) calloc(1,s)
+# define FREEMEM(p) free(p)
+#endif
+
+#include <string.h> /* memset, memcpy */
+#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
+
+static int LZ4_isAligned(const void* ptr, size_t alignment)
+{
+ return ((size_t)ptr & (alignment -1)) == 0;
+}
+
+
+/*-************************************
+* Types
+**************************************/
+#include <limits.h>
+#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
+# if UINT_MAX != 4294967295UL
+# error "LZ4 code (when not C++ or C99) assumes that sizeof(int) == 4"
+# endif
+ 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
+**************************************/
+
+/**
+ * LZ4 relies on memcpy with a constant size being inlined. In freestanding
+ * environments, the compiler can't assume the implementation of memcpy() is
+ * standard compliant, so it can't apply its specialized memcpy() inlining
+ * logic. When possible, use __builtin_memcpy() to tell the compiler to analyze
+ * memcpy() as if it were standard compliant, so it can inline it in freestanding
+ * environments. This is needed when decompressing the Linux Kernel, for example.
+ */
+#if defined(__GNUC__) && (__GNUC__ >= 4)
+#define LZ4_memcpy(dst, src, size) __builtin_memcpy(dst, src, size)
+#else
+#define LZ4_memcpy(dst, src, size) memcpy(dst, src, size)
+#endif
+
+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; LZ4_memcpy(&val, memPtr, sizeof(val)); return val;
+}
+
+static U32 LZ4_read32(const void* memPtr)
+{
+ U32 val; LZ4_memcpy(&val, memPtr, sizeof(val)); return val;
+}
+
+static reg_t LZ4_read_ARCH(const void* memPtr)
+{
+ reg_t val; LZ4_memcpy(&val, memPtr, sizeof(val)); return val;
+}
+
+static void LZ4_write16(void* memPtr, U16 value)
+{
+ LZ4_memcpy(memPtr, &value, sizeof(value));
+}
+
+static void LZ4_write32(void* memPtr, U32 value)
+{
+ LZ4_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_INLINE
+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 { LZ4_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 _M_IX86 || defined __x86_64__ || defined _M_X64
+# define LZ4_FAST_DEC_LOOP 1
+# elif defined(__aarch64__) && !defined(__clang__)
+ /* On aarch64, we disable this optimization for clang because on certain
+ * mobile chipsets, performance is reduced with clang. For 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_INLINE void
+LZ4_memcpy_using_offset_base(BYTE* dstPtr, const BYTE* srcPtr, BYTE* dstEnd, const size_t offset)
+{
+ assert(srcPtr + offset == dstPtr);
+ if (offset < 8) {
+ LZ4_write32(dstPtr, 0); /* silence an msan warning when offset==0 */
+ dstPtr[0] = srcPtr[0];
+ dstPtr[1] = srcPtr[1];
+ dstPtr[2] = srcPtr[2];
+ dstPtr[3] = srcPtr[3];
+ srcPtr += inc32table[offset];
+ LZ4_memcpy(dstPtr+4, srcPtr, 4);
+ srcPtr -= dec64table[offset];
+ dstPtr += 8;
+ } else {
+ LZ4_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_INLINE void
+LZ4_wildCopy32(void* dstPtr, const void* srcPtr, void* dstEnd)
+{
+ BYTE* d = (BYTE*)dstPtr;
+ const BYTE* s = (const BYTE*)srcPtr;
+ BYTE* const e = (BYTE*)dstEnd;
+
+ do { LZ4_memcpy(d,s,16); LZ4_memcpy(d+16,s+16,16); d+=32; s+=32; } while (d<e);
+}
+
+/* LZ4_memcpy_using_offset() presumes :
+ * - dstEnd >= dstPtr + MINMATCH
+ * - there is at least 8 bytes available to write after dstEnd */
+LZ4_FORCE_INLINE void
+LZ4_memcpy_using_offset(BYTE* dstPtr, const BYTE* srcPtr, BYTE* dstEnd, const size_t offset)
+{
+ BYTE v[8];
+
+ assert(dstEnd >= dstPtr + MINMATCH);
+
+ switch(offset) {
+ case 1:
+ MEM_INIT(v, *srcPtr, 8);
+ break;
+ case 2:
+ LZ4_memcpy(v, srcPtr, 2);
+ LZ4_memcpy(&v[2], srcPtr, 2);
+ LZ4_memcpy(&v[4], v, 4);
+ break;
+ case 4:
+ LZ4_memcpy(v, srcPtr, 4);
+ LZ4_memcpy(&v[4], srcPtr, 4);
+ break;
+ default:
+ LZ4_memcpy_using_offset_base(dstPtr, srcPtr, dstEnd, offset);
+ return;
+ }
+
+ LZ4_memcpy(dstPtr, v, 8);
+ dstPtr += 8;
+ while (dstPtr < dstEnd) {
+ LZ4_memcpy(dstPtr, v, 8);
+ dstPtr += 8;
+ }
+}
+#endif
+
+
+/*-************************************
+* Common functions
+**************************************/
+static unsigned LZ4_NbCommonBytes (reg_t val)
+{
+ assert(val != 0);
+ if (LZ4_isLittleEndian()) {
+ if (sizeof(val) == 8) {
+# if defined(_MSC_VER) && (_MSC_VER >= 1800) && defined(_M_AMD64) && !defined(LZ4_FORCE_SW_BITCOUNT)
+ /* x64 CPUS without BMI support interpret `TZCNT` as `REP BSF` */
+ return (unsigned)_tzcnt_u64(val) >> 3;
+# elif defined(_MSC_VER) && defined(_WIN64) && !defined(LZ4_FORCE_SW_BITCOUNT)
+ unsigned long r = 0;
+ _BitScanForward64(&r, (U64)val);
+ return (unsigned)r >> 3;
+# elif (defined(__clang__) || (defined(__GNUC__) && ((__GNUC__ > 3) || \
+ ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4))))) && \
+ !defined(LZ4_FORCE_SW_BITCOUNT)
+ return (unsigned)__builtin_ctzll((U64)val) >> 3;
+# else
+ const U64 m = 0x0101010101010101ULL;
+ val ^= val - 1;
+ return (unsigned)(((U64)((val & (m - 1)) * m)) >> 56);
+# endif
+ } else /* 32 bits */ {
+# if defined(_MSC_VER) && (_MSC_VER >= 1400) && !defined(LZ4_FORCE_SW_BITCOUNT)
+ unsigned long r;
+ _BitScanForward(&r, (U32)val);
+ return (unsigned)r >> 3;
+# elif (defined(__clang__) || (defined(__GNUC__) && ((__GNUC__ > 3) || \
+ ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4))))) && \
+ !defined(__TINYC__) && !defined(LZ4_FORCE_SW_BITCOUNT)
+ return (unsigned)__builtin_ctz((U32)val) >> 3;
+# else
+ const U32 m = 0x01010101;
+ return (unsigned)((((val - 1) ^ val) & (m - 1)) * m) >> 24;
+# endif
+ }
+ } else /* Big Endian CPU */ {
+ if (sizeof(val)==8) {
+# if (defined(__clang__) || (defined(__GNUC__) && ((__GNUC__ > 3) || \
+ ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4))))) && \
+ !defined(__TINYC__) && !defined(LZ4_FORCE_SW_BITCOUNT)
+ return (unsigned)__builtin_clzll((U64)val) >> 3;
+# else
+#if 1
+ /* this method is probably faster,
+ * but adds a 128 bytes lookup table */
+ static const unsigned char ctz7_tab[128] = {
+ 7, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ };
+ U64 const mask = 0x0101010101010101ULL;
+ U64 const t = (((val >> 8) - mask) | val) & mask;
+ return ctz7_tab[(t * 0x0080402010080402ULL) >> 57];
+#else
+ /* this method doesn't consume memory space like the previous one,
+ * but it contains several branches,
+ * that may end up slowing execution */
+ static const U32 by32 = sizeof(val)*4; /* 32 on 64 bits (goal), 16 on 32 bits.
+ Just to avoid some static analyzer complaining about shift by 32 on 32-bits target.
+ Note that this code path is never triggered in 32-bits mode. */
+ unsigned r;
+ if (!(val>>by32)) { r=4; } else { r=0; val>>=by32; }
+ if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
+ r += (!val);
+ return r;
+#endif
+# endif
+ } else /* 32 bits */ {
+# if (defined(__clang__) || (defined(__GNUC__) && ((__GNUC__ > 3) || \
+ ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4))))) && \
+ !defined(LZ4_FORCE_SW_BITCOUNT)
+ return (unsigned)__builtin_clz((U32)val) >> 3;
+# else
+ val >>= 8;
+ val = ((((val + 0x00FFFF00) | 0x00FFFFFF) + val) |
+ (val + 0x00FF0000)) >> 24;
+ return (unsigned)val ^ 3;
+# endif
+ }
+ }
+}
+
+
+#define STEPSIZE sizeof(reg_t)
+LZ4_FORCE_INLINE
+unsigned LZ4_count(const BYTE* pIn, const BYTE* pMatch, const BYTE* pInLimit)
+{
+ const BYTE* const pStart = pIn;
+
+ if (likely(pIn < pInLimit-(STEPSIZE-1))) {
+ reg_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn);
+ if (!diff) {
+ pIn+=STEPSIZE; pMatch+=STEPSIZE;
+ } else {
+ return LZ4_NbCommonBytes(diff);
+ } }
+
+ while (likely(pIn < pInLimit-(STEPSIZE-1))) {
+ reg_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn);
+ if (!diff) { pIn+=STEPSIZE; pMatch+=STEPSIZE; continue; }
+ pIn += LZ4_NbCommonBytes(diff);
+ return (unsigned)(pIn - pStart);
+ }
+
+ if ((STEPSIZE==8) && (pIn<(pInLimit-3)) && (LZ4_read32(pMatch) == LZ4_read32(pIn))) { pIn+=4; pMatch+=4; }
+ if ((pIn<(pInLimit-1)) && (LZ4_read16(pMatch) == LZ4_read16(pIn))) { pIn+=2; pMatch+=2; }
+ if ((pIn<pInLimit) && (*pMatch == *pIn)) pIn++;
+ return (unsigned)(pIn - pStart);
+}
+
+
+#ifndef LZ4_COMMONDEFS_ONLY
+/*-************************************
+* Local Constants
+**************************************/
+static const int LZ4_64Klimit = ((64 KB) + (MFLIMIT-1));
+static const U32 LZ4_skipTrigger = 6; /* Increase this value ==> compression run slower on incompressible data */
+
+
+/*-************************************
+* Local Structures and types
+**************************************/
+typedef enum { clearedTable = 0, byPtr, byU32, byU16 } tableType_t;
+
+/**
+ * This enum distinguishes several different modes of accessing previous
+ * content in the stream.
+ *
+ * - noDict : There is no preceding content.
+ * - withPrefix64k : Table entries up to ctx->dictSize before the current blob
+ * blob being compressed are valid and refer to the preceding
+ * content (of length ctx->dictSize), which is available
+ * contiguously preceding in memory the content currently
+ * being compressed.
+ * - usingExtDict : Like withPrefix64k, but the preceding content is somewhere
+ * else in memory, starting at ctx->dictionary with length
+ * ctx->dictSize.
+ * - usingDictCtx : Like usingExtDict, but everything concerning the preceding
+ * content is in a separate context, pointed to by
+ * ctx->dictCtx. ctx->dictionary, ctx->dictSize, and table
+ * entries in the current context that refer to positions
+ * preceding the beginning of the current compression are
+ * ignored. Instead, ctx->dictCtx->dictionary and ctx->dictCtx
+ * ->dictSize describe the location and size of the preceding
+ * content, and matches are found by looking in the ctx
+ * ->dictCtx->hashTable.
+ */
+typedef enum { noDict = 0, withPrefix64k, usingExtDict, usingDictCtx } dict_directive;
+typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive;
+
+
+/*-************************************
+* Local Utils
+**************************************/
+int LZ4_versionNumber (void) { return LZ4_VERSION_NUMBER; }
+const char* LZ4_versionString(void) { return LZ4_VERSION_STRING; }
+int LZ4_compressBound(int isize) { return LZ4_COMPRESSBOUND(isize); }
+int LZ4_sizeofState(void) { return LZ4_STREAMSIZE; }
+
+
+/*-************************************
+* Internal Definitions used in Tests
+**************************************/
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+int LZ4_compress_forceExtDict (LZ4_stream_t* LZ4_dict, const char* source, char* dest, int srcSize);
+
+int LZ4_decompress_safe_forceExtDict(const char* source, char* dest,
+ int compressedSize, int maxOutputSize,
+ const void* dictStart, size_t dictSize);
+
+#if defined (__cplusplus)
+}
+#endif
+
+/*-******************************
+* Compression functions
+********************************/
+LZ4_FORCE_INLINE U32 LZ4_hash4(U32 sequence, tableType_t const tableType)
+{
+ if (tableType == byU16)
+ return ((sequence * 2654435761U) >> ((MINMATCH*8)-(LZ4_HASHLOG+1)));
+ else
+ return ((sequence * 2654435761U) >> ((MINMATCH*8)-LZ4_HASHLOG));
+}
+
+LZ4_FORCE_INLINE U32 LZ4_hash5(U64 sequence, tableType_t const tableType)
+{
+ const U32 hashLog = (tableType == byU16) ? LZ4_HASHLOG+1 : LZ4_HASHLOG;
+ if (LZ4_isLittleEndian()) {
+ const U64 prime5bytes = 889523592379ULL;
+ return (U32)(((sequence << 24) * prime5bytes) >> (64 - hashLog));
+ } else {
+ const U64 prime8bytes = 11400714785074694791ULL;
+ return (U32)(((sequence >> 24) * prime8bytes) >> (64 - hashLog));
+ }
+}
+
+LZ4_FORCE_INLINE U32 LZ4_hashPosition(const void* const p, tableType_t const tableType)
+{
+ if ((sizeof(reg_t)==8) && (tableType != byU16)) return LZ4_hash5(LZ4_read_ARCH(p), tableType);
+ return LZ4_hash4(LZ4_read32(p), tableType);
+}
+
+LZ4_FORCE_INLINE void LZ4_clearHash(U32 h, void* tableBase, tableType_t const tableType)
+{
+ switch (tableType)
+ {
+ default: /* fallthrough */
+ case clearedTable: { /* illegal! */ assert(0); return; }
+ case byPtr: { const BYTE** hashTable = (const BYTE**)tableBase; hashTable[h] = NULL; return; }
+ case byU32: { U32* hashTable = (U32*) tableBase; hashTable[h] = 0; return; }
+ case byU16: { U16* hashTable = (U16*) tableBase; hashTable[h] = 0; return; }
+ }
+}
+
+LZ4_FORCE_INLINE void LZ4_putIndexOnHash(U32 idx, U32 h, void* tableBase, tableType_t const tableType)
+{
+ switch (tableType)
+ {
+ default: /* fallthrough */
+ case clearedTable: /* fallthrough */
+ case byPtr: { /* illegal! */ assert(0); return; }
+ case byU32: { U32* hashTable = (U32*) tableBase; hashTable[h] = idx; return; }
+ case byU16: { U16* hashTable = (U16*) tableBase; assert(idx < 65536); hashTable[h] = (U16)idx; return; }
+ }
+}
+
+LZ4_FORCE_INLINE void LZ4_putPositionOnHash(const BYTE* p, U32 h,
+ void* tableBase, tableType_t const tableType,
+ const BYTE* srcBase)
+{
+ switch (tableType)
+ {
+ case clearedTable: { /* illegal! */ assert(0); return; }
+ case byPtr: { const BYTE** hashTable = (const BYTE**)tableBase; hashTable[h] = p; return; }
+ case byU32: { U32* hashTable = (U32*) tableBase; hashTable[h] = (U32)(p-srcBase); return; }
+ case byU16: { U16* hashTable = (U16*) tableBase; hashTable[h] = (U16)(p-srcBase); return; }
+ }
+}
+
+LZ4_FORCE_INLINE void LZ4_putPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
+{
+ U32 const h = LZ4_hashPosition(p, tableType);
+ LZ4_putPositionOnHash(p, h, tableBase, tableType, srcBase);
+}
+
+/* LZ4_getIndexOnHash() :
+ * Index of match position registered in hash table.
+ * hash position must be calculated by using base+index, or dictBase+index.
+ * Assumption 1 : only valid if tableType == byU32 or byU16.
+ * Assumption 2 : h is presumed valid (within limits of hash table)
+ */
+LZ4_FORCE_INLINE U32 LZ4_getIndexOnHash(U32 h, const void* tableBase, tableType_t tableType)
+{
+ LZ4_STATIC_ASSERT(LZ4_MEMORY_USAGE > 2);
+ if (tableType == byU32) {
+ const U32* const hashTable = (const U32*) tableBase;
+ assert(h < (1U << (LZ4_MEMORY_USAGE-2)));
+ return hashTable[h];
+ }
+ if (tableType == byU16) {
+ const U16* const hashTable = (const U16*) tableBase;
+ assert(h < (1U << (LZ4_MEMORY_USAGE-1)));
+ return hashTable[h];
+ }
+ assert(0); return 0; /* forbidden case */
+}
+
+static const BYTE* LZ4_getPositionOnHash(U32 h, const void* tableBase, tableType_t tableType, const BYTE* srcBase)
+{
+ if (tableType == byPtr) { const BYTE* const* hashTable = (const BYTE* const*) tableBase; return hashTable[h]; }
+ if (tableType == byU32) { const U32* const hashTable = (const U32*) tableBase; return hashTable[h] + srcBase; }
+ { const U16* const hashTable = (const U16*) tableBase; return hashTable[h] + srcBase; } /* default, to ensure a return */
+}
+
+LZ4_FORCE_INLINE const BYTE*
+LZ4_getPosition(const BYTE* p,
+ const void* tableBase, tableType_t tableType,
+ const BYTE* srcBase)
+{
+ U32 const h = LZ4_hashPosition(p, tableType);
+ return LZ4_getPositionOnHash(h, tableBase, tableType, srcBase);
+}
+
+LZ4_FORCE_INLINE void
+LZ4_prepareTable(LZ4_stream_t_internal* const cctx,
+ const int inputSize,
+ const tableType_t tableType) {
+ /* If the table hasn't been used, it's guaranteed to be zeroed out, and is
+ * therefore safe to use no matter what mode we're in. Otherwise, we figure
+ * out if it's safe to leave as is or whether it needs to be reset.
+ */
+ if ((tableType_t)cctx->tableType != clearedTable) {
+ assert(inputSize >= 0);
+ if ((tableType_t)cctx->tableType != tableType
+ || ((tableType == byU16) && cctx->currentOffset + (unsigned)inputSize >= 0xFFFFU)
+ || ((tableType == byU32) && cctx->currentOffset > 1 GB)
+ || tableType == byPtr
+ || inputSize >= 4 KB)
+ {
+ DEBUGLOG(4, "LZ4_prepareTable: Resetting table in %p", cctx);
+ MEM_INIT(cctx->hashTable, 0, LZ4_HASHTABLESIZE);
+ cctx->currentOffset = 0;
+ cctx->tableType = (U32)clearedTable;
+ } else {
+ DEBUGLOG(4, "LZ4_prepareTable: Re-use hash table (no reset)");
+ }
+ }
+
+ /* Adding a gap, so all previous entries are > LZ4_DISTANCE_MAX back, is faster
+ * than compressing without a gap. However, compressing with
+ * currentOffset == 0 is faster still, so we preserve that case.
+ */
+ if (cctx->currentOffset != 0 && tableType == byU32) {
+ DEBUGLOG(5, "LZ4_prepareTable: adding 64KB to currentOffset");
+ cctx->currentOffset += 64 KB;
+ }
+
+ /* Finally, clear history */
+ cctx->dictCtx = NULL;
+ cctx->dictionary = NULL;
+ cctx->dictSize = 0;
+}
+
+/** LZ4_compress_generic() :
+ * inlined, to ensure branches are decided at compilation time.
+ * Presumed already validated at this stage:
+ * - source != NULL
+ * - inputSize > 0
+ */
+LZ4_FORCE_INLINE int LZ4_compress_generic_validated(
+ LZ4_stream_t_internal* const cctx,
+ const char* const source,
+ char* const dest,
+ const int inputSize,
+ int *inputConsumed, /* only written when outputDirective == fillOutput */
+ const int maxOutputSize,
+ const limitedOutput_directive outputDirective,
+ const tableType_t tableType,
+ const dict_directive dictDirective,
+ const dictIssue_directive dictIssue,
+ const int acceleration)
+{
+ int result;
+ const BYTE* ip = (const BYTE*) source;
+
+ U32 const startIndex = cctx->currentOffset;
+ const BYTE* base = (const BYTE*) source - startIndex;
+ const BYTE* lowLimit;
+
+ const LZ4_stream_t_internal* dictCtx = (const LZ4_stream_t_internal*) cctx->dictCtx;
+ const BYTE* const dictionary =
+ dictDirective == usingDictCtx ? dictCtx->dictionary : cctx->dictionary;
+ const U32 dictSize =
+ dictDirective == usingDictCtx ? dictCtx->dictSize : cctx->dictSize;
+ const U32 dictDelta = (dictDirective == usingDictCtx) ? startIndex - dictCtx->currentOffset : 0; /* make indexes in dictCtx comparable with index in current context */
+
+ int const maybe_extMem = (dictDirective == usingExtDict) || (dictDirective == usingDictCtx);
+ U32 const prefixIdxLimit = startIndex - dictSize; /* used when dictDirective == dictSmall */
+ const BYTE* const dictEnd = dictionary ? dictionary + dictSize : dictionary;
+ const BYTE* anchor = (const BYTE*) source;
+ const BYTE* const iend = ip + inputSize;
+ const BYTE* const mflimitPlusOne = iend - MFLIMIT + 1;
+ const BYTE* const matchlimit = iend - LASTLITERALS;
+
+ /* the dictCtx currentOffset is indexed on the start of the dictionary,
+ * while a dictionary in the current context precedes the currentOffset */
+ const BYTE* dictBase = !dictionary ? NULL : (dictDirective == usingDictCtx) ?
+ dictionary + dictSize - dictCtx->currentOffset :
+ dictionary + dictSize - startIndex;
+
+ BYTE* op = (BYTE*) dest;
+ BYTE* const olimit = op + maxOutputSize;
+
+ U32 offset = 0;
+ U32 forwardH;
+
+ DEBUGLOG(5, "LZ4_compress_generic_validated: srcSize=%i, tableType=%u", inputSize, tableType);
+ assert(ip != NULL);
+ /* If init conditions are not met, we don't have to mark stream
+ * as having dirty context, since no action was taken yet */
+ if (outputDirective == fillOutput && maxOutputSize < 1) { return 0; } /* Impossible to store anything */
+ if ((tableType == byU16) && (inputSize>=LZ4_64Klimit)) { return 0; } /* Size too large (not within 64K limit) */
+ if (tableType==byPtr) assert(dictDirective==noDict); /* only supported use case with byPtr */
+ assert(acceleration >= 1);
+
+ lowLimit = (const BYTE*)source - (dictDirective == withPrefix64k ? dictSize : 0);
+
+ /* Update context state */
+ if (dictDirective == usingDictCtx) {
+ /* Subsequent linked blocks can't use the dictionary. */
+ /* Instead, they use the block we just compressed. */
+ cctx->dictCtx = NULL;
+ cctx->dictSize = (U32)inputSize;
+ } else {
+ cctx->dictSize += (U32)inputSize;
+ }
+ cctx->currentOffset += (U32)inputSize;
+ cctx->tableType = (U32)tableType;
+
+ if (inputSize<LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */
+
+ /* First Byte */
+ LZ4_putPosition(ip, cctx->hashTable, tableType, base);
+ ip++; forwardH = LZ4_hashPosition(ip, tableType);
+
+ /* Main Loop */
+ for ( ; ; ) {
+ const BYTE* match;
+ BYTE* token;
+ const BYTE* filledIp;
+
+ /* Find a match */
+ if (tableType == byPtr) {
+ const BYTE* forwardIp = ip;
+ int step = 1;
+ int searchMatchNb = acceleration << LZ4_skipTrigger;
+ do {
+ U32 const h = forwardH;
+ ip = forwardIp;
+ forwardIp += step;
+ step = (searchMatchNb++ >> LZ4_skipTrigger);
+
+ if (unlikely(forwardIp > mflimitPlusOne)) goto _last_literals;
+ assert(ip < mflimitPlusOne);
+
+ match = LZ4_getPositionOnHash(h, cctx->hashTable, tableType, base);
+ forwardH = LZ4_hashPosition(forwardIp, tableType);
+ LZ4_putPositionOnHash(ip, h, cctx->hashTable, tableType, base);
+
+ } while ( (match+LZ4_DISTANCE_MAX < ip)
+ || (LZ4_read32(match) != LZ4_read32(ip)) );
+
+ } else { /* byU32, byU16 */
+
+ const BYTE* forwardIp = ip;
+ int step = 1;
+ int searchMatchNb = acceleration << LZ4_skipTrigger;
+ do {
+ U32 const h = forwardH;
+ U32 const current = (U32)(forwardIp - base);
+ U32 matchIndex = LZ4_getIndexOnHash(h, cctx->hashTable, tableType);
+ assert(matchIndex <= current);
+ assert(forwardIp - base < (ptrdiff_t)(2 GB - 1));
+ ip = forwardIp;
+ forwardIp += step;
+ step = (searchMatchNb++ >> LZ4_skipTrigger);
+
+ if (unlikely(forwardIp > mflimitPlusOne)) goto _last_literals;
+ assert(ip < mflimitPlusOne);
+
+ if (dictDirective == usingDictCtx) {
+ if (matchIndex < startIndex) {
+ /* there was no match, try the dictionary */
+ assert(tableType == byU32);
+ matchIndex = LZ4_getIndexOnHash(h, dictCtx->hashTable, byU32);
+ match = dictBase + matchIndex;
+ matchIndex += dictDelta; /* make dictCtx index comparable with current context */
+ lowLimit = dictionary;
+ } else {
+ match = base + matchIndex;
+ lowLimit = (const BYTE*)source;
+ }
+ } else if (dictDirective==usingExtDict) {
+ if (matchIndex < startIndex) {
+ DEBUGLOG(7, "extDict candidate: matchIndex=%5u < startIndex=%5u", matchIndex, startIndex);
+ assert(startIndex - matchIndex >= MINMATCH);
+ match = dictBase + matchIndex;
+ lowLimit = dictionary;
+ } else {
+ match = base + matchIndex;
+ lowLimit = (const BYTE*)source;
+ }
+ } else { /* single continuous memory segment */
+ match = base + matchIndex;
+ }
+ forwardH = LZ4_hashPosition(forwardIp, tableType);
+ LZ4_putIndexOnHash(current, h, cctx->hashTable, tableType);
+
+ DEBUGLOG(7, "candidate at pos=%u (offset=%u \n", matchIndex, current - matchIndex);
+ if ((dictIssue == dictSmall) && (matchIndex < prefixIdxLimit)) { continue; } /* match outside of valid area */
+ assert(matchIndex < current);
+ if ( ((tableType != byU16) || (LZ4_DISTANCE_MAX < LZ4_DISTANCE_ABSOLUTE_MAX))
+ && (matchIndex+LZ4_DISTANCE_MAX < current)) {
+ continue;
+ } /* too far */
+ assert((current - matchIndex) <= LZ4_DISTANCE_MAX); /* match now expected within distance */
+
+ if (LZ4_read32(match) == LZ4_read32(ip)) {
+ if (maybe_extMem) offset = current - matchIndex;
+ break; /* match found */
+ }
+
+ } while(1);
+ }
+
+ /* Catch up */
+ filledIp = ip;
+ while (((ip>anchor) & (match > lowLimit)) && (unlikely(ip[-1]==match[-1]))) { ip--; match--; }
+
+ /* Encode Literals */
+ { unsigned const litLength = (unsigned)(ip - anchor);
+ token = op++;
+ if ((outputDirective == limitedOutput) && /* Check output buffer overflow */
+ (unlikely(op + litLength + (2 + 1 + LASTLITERALS) + (litLength/255) > olimit)) ) {
+ return 0; /* cannot compress within `dst` budget. Stored indexes in hash table are nonetheless fine */
+ }
+ if ((outputDirective == fillOutput) &&
+ (unlikely(op + (litLength+240)/255 /* litlen */ + litLength /* literals */ + 2 /* offset */ + 1 /* token */ + MFLIMIT - MINMATCH /* min last literals so last match is <= end - MFLIMIT */ > olimit))) {
+ op--;
+ goto _last_literals;
+ }
+ if (litLength >= RUN_MASK) {
+ int len = (int)(litLength - RUN_MASK);
+ *token = (RUN_MASK<<ML_BITS);
+ for(; len >= 255 ; len-=255) *op++ = 255;
+ *op++ = (BYTE)len;
+ }
+ else *token = (BYTE)(litLength<<ML_BITS);
+
+ /* Copy Literals */
+ LZ4_wildCopy8(op, anchor, op+litLength);
+ op+=litLength;
+ DEBUGLOG(6, "seq.start:%i, literals=%u, match.start:%i",
+ (int)(anchor-(const BYTE*)source), litLength, (int)(ip-(const BYTE*)source));
+ }
+
+_next_match:
+ /* at this stage, the following variables must be correctly set :
+ * - ip : at start of LZ operation
+ * - match : at start of previous pattern occurence; can be within current prefix, or within extDict
+ * - offset : if maybe_ext_memSegment==1 (constant)
+ * - lowLimit : must be == dictionary to mean "match is within extDict"; must be == source otherwise
+ * - token and *token : position to write 4-bits for match length; higher 4-bits for literal length supposed already written
+ */
+
+ if ((outputDirective == fillOutput) &&
+ (op + 2 /* offset */ + 1 /* token */ + MFLIMIT - MINMATCH /* min last literals so last match is <= end - MFLIMIT */ > olimit)) {
+ /* the match was too close to the end, rewind and go to last literals */
+ op = token;
+ goto _last_literals;
+ }
+
+ /* Encode Offset */
+ if (maybe_extMem) { /* static test */
+ DEBUGLOG(6, " with offset=%u (ext if > %i)", offset, (int)(ip - (const BYTE*)source));
+ assert(offset <= LZ4_DISTANCE_MAX && offset > 0);
+ LZ4_writeLE16(op, (U16)offset); op+=2;
+ } else {
+ DEBUGLOG(6, " with offset=%u (same segment)", (U32)(ip - match));
+ assert(ip-match <= LZ4_DISTANCE_MAX);
+ LZ4_writeLE16(op, (U16)(ip - match)); op+=2;
+ }
+
+ /* Encode MatchLength */
+ { unsigned matchCode;
+
+ if ( (dictDirective==usingExtDict || dictDirective==usingDictCtx)
+ && (lowLimit==dictionary) /* match within extDict */ ) {
+ const BYTE* limit = ip + (dictEnd-match);
+ assert(dictEnd > match);
+ if (limit > matchlimit) limit = matchlimit;
+ matchCode = LZ4_count(ip+MINMATCH, match+MINMATCH, limit);
+ ip += (size_t)matchCode + MINMATCH;
+ if (ip==limit) {
+ unsigned const more = LZ4_count(limit, (const BYTE*)source, matchlimit);
+ matchCode += more;
+ ip += more;
+ }
+ DEBUGLOG(6, " with matchLength=%u starting in extDict", matchCode+MINMATCH);
+ } else {
+ matchCode = LZ4_count(ip+MINMATCH, match+MINMATCH, matchlimit);
+ ip += (size_t)matchCode + MINMATCH;
+ DEBUGLOG(6, " with matchLength=%u", matchCode+MINMATCH);
+ }
+
+ if ((outputDirective) && /* Check output buffer overflow */
+ (unlikely(op + (1 + LASTLITERALS) + (matchCode+240)/255 > olimit)) ) {
+ if (outputDirective == fillOutput) {
+ /* Match description too long : reduce it */
+ U32 newMatchCode = 15 /* in token */ - 1 /* to avoid needing a zero byte */ + ((U32)(olimit - op) - 1 - LASTLITERALS) * 255;
+ ip -= matchCode - newMatchCode;
+ assert(newMatchCode < matchCode);
+ matchCode = newMatchCode;
+ if (unlikely(ip <= filledIp)) {
+ /* We have already filled up to filledIp so if ip ends up less than filledIp
+ * we have positions in the hash table beyond the current position. This is
+ * a problem if we reuse the hash table. So we have to remove these positions
+ * from the hash table.
+ */
+ const BYTE* ptr;
+ DEBUGLOG(5, "Clearing %u positions", (U32)(filledIp - ip));
+ for (ptr = ip; ptr <= filledIp; ++ptr) {
+ U32 const h = LZ4_hashPosition(ptr, tableType);
+ LZ4_clearHash(h, cctx->hashTable, tableType);
+ }
+ }
+ } else {
+ assert(outputDirective == limitedOutput);
+ return 0; /* cannot compress within `dst` budget. Stored indexes in hash table are nonetheless fine */
+ }
+ }
+ if (matchCode >= ML_MASK) {
+ *token += ML_MASK;
+ matchCode -= ML_MASK;
+ LZ4_write32(op, 0xFFFFFFFF);
+ while (matchCode >= 4*255) {
+ op+=4;
+ LZ4_write32(op, 0xFFFFFFFF);
+ matchCode -= 4*255;
+ }
+ op += matchCode / 255;
+ *op++ = (BYTE)(matchCode % 255);
+ } else
+ *token += (BYTE)(matchCode);
+ }
+ /* Ensure we have enough space for the last literals. */
+ assert(!(outputDirective == fillOutput && op + 1 + LASTLITERALS > olimit));
+
+ anchor = ip;
+
+ /* Test end of chunk */
+ if (ip >= mflimitPlusOne) break;
+
+ /* Fill table */
+ LZ4_putPosition(ip-2, cctx->hashTable, tableType, base);
+
+ /* Test next position */
+ if (tableType == byPtr) {
+
+ match = LZ4_getPosition(ip, cctx->hashTable, tableType, base);
+ LZ4_putPosition(ip, cctx->hashTable, tableType, base);
+ if ( (match+LZ4_DISTANCE_MAX >= ip)
+ && (LZ4_read32(match) == LZ4_read32(ip)) )
+ { token=op++; *token=0; goto _next_match; }
+
+ } else { /* byU32, byU16 */
+
+ U32 const h = LZ4_hashPosition(ip, tableType);
+ U32 const current = (U32)(ip-base);
+ U32 matchIndex = LZ4_getIndexOnHash(h, cctx->hashTable, tableType);
+ assert(matchIndex < current);
+ if (dictDirective == usingDictCtx) {
+ if (matchIndex < startIndex) {
+ /* there was no match, try the dictionary */
+ matchIndex = LZ4_getIndexOnHash(h, dictCtx->hashTable, byU32);
+ match = dictBase + matchIndex;
+ lowLimit = dictionary; /* required for match length counter */
+ matchIndex += dictDelta;
+ } else {
+ match = base + matchIndex;
+ lowLimit = (const BYTE*)source; /* required for match length counter */
+ }
+ } else if (dictDirective==usingExtDict) {
+ if (matchIndex < startIndex) {
+ match = dictBase + matchIndex;
+ lowLimit = dictionary; /* required for match length counter */
+ } else {
+ match = base + matchIndex;
+ lowLimit = (const BYTE*)source; /* required for match length counter */
+ }
+ } else { /* single memory segment */
+ match = base + matchIndex;
+ }
+ LZ4_putIndexOnHash(current, h, cctx->hashTable, tableType);
+ assert(matchIndex < current);
+ if ( ((dictIssue==dictSmall) ? (matchIndex >= prefixIdxLimit) : 1)
+ && (((tableType==byU16) && (LZ4_DISTANCE_MAX == LZ4_DISTANCE_ABSOLUTE_MAX)) ? 1 : (matchIndex+LZ4_DISTANCE_MAX >= current))
+ && (LZ4_read32(match) == LZ4_read32(ip)) ) {
+ token=op++;
+ *token=0;
+ if (maybe_extMem) offset = current - matchIndex;
+ DEBUGLOG(6, "seq.start:%i, literals=%u, match.start:%i",
+ (int)(anchor-(const BYTE*)source), 0, (int)(ip-(const BYTE*)source));
+ goto _next_match;
+ }
+ }
+
+ /* Prepare next loop */
+ forwardH = LZ4_hashPosition(++ip, tableType);
+
+ }
+
+_last_literals:
+ /* Encode Last Literals */
+ { size_t lastRun = (size_t)(iend - anchor);
+ if ( (outputDirective) && /* Check output buffer overflow */
+ (op + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > olimit)) {
+ if (outputDirective == fillOutput) {
+ /* adapt lastRun to fill 'dst' */
+ assert(olimit >= op);
+ lastRun = (size_t)(olimit-op) - 1/*token*/;
+ lastRun -= (lastRun + 256 - RUN_MASK) / 256; /*additional length tokens*/
+ } else {
+ assert(outputDirective == limitedOutput);
+ return 0; /* cannot compress within `dst` budget. Stored indexes in hash table are nonetheless fine */
+ }
+ }
+ DEBUGLOG(6, "Final literal run : %i literals", (int)lastRun);
+ if (lastRun >= RUN_MASK) {
+ size_t accumulator = lastRun - RUN_MASK;
+ *op++ = RUN_MASK << ML_BITS;
+ for(; accumulator >= 255 ; accumulator-=255) *op++ = 255;
+ *op++ = (BYTE) accumulator;
+ } else {
+ *op++ = (BYTE)(lastRun<<ML_BITS);
+ }
+ LZ4_memcpy(op, anchor, lastRun);
+ ip = anchor + lastRun;
+ op += lastRun;
+ }
+
+ if (outputDirective == fillOutput) {
+ *inputConsumed = (int) (((const char*)ip)-source);
+ }
+ result = (int)(((char*)op) - dest);
+ assert(result > 0);
+ DEBUGLOG(5, "LZ4_compress_generic: compressed %i bytes into %i bytes", inputSize, result);
+ return result;
+}
+
+/** LZ4_compress_generic() :
+ * inlined, to ensure branches are decided at compilation time;
+ * takes care of src == (NULL, 0)
+ * and forward the rest to LZ4_compress_generic_validated */
+LZ4_FORCE_INLINE int LZ4_compress_generic(
+ LZ4_stream_t_internal* const cctx,
+ const char* const src,
+ char* const dst,
+ const int srcSize,
+ int *inputConsumed, /* only written when outputDirective == fillOutput */
+ const int dstCapacity,
+ const limitedOutput_directive outputDirective,
+ const tableType_t tableType,
+ const dict_directive dictDirective,
+ const dictIssue_directive dictIssue,
+ const int acceleration)
+{
+ DEBUGLOG(5, "LZ4_compress_generic: srcSize=%i, dstCapacity=%i",
+ srcSize, dstCapacity);
+
+ if ((U32)srcSize > (U32)LZ4_MAX_INPUT_SIZE) { return 0; } /* Unsupported srcSize, too large (or negative) */
+ if (srcSize == 0) { /* src == NULL supported if srcSize == 0 */
+ if (outputDirective != notLimited && dstCapacity <= 0) return 0; /* no output, can't write anything */
+ DEBUGLOG(5, "Generating an empty block");
+ assert(outputDirective == notLimited || dstCapacity >= 1);
+ assert(dst != NULL);
+ dst[0] = 0;
+ if (outputDirective == fillOutput) {
+ assert (inputConsumed != NULL);
+ *inputConsumed = 0;
+ }
+ return 1;
+ }
+ assert(src != NULL);
+
+ return LZ4_compress_generic_validated(cctx, src, dst, srcSize,
+ inputConsumed, /* only written into if outputDirective == fillOutput */
+ dstCapacity, outputDirective,
+ tableType, dictDirective, dictIssue, acceleration);
+}
+
+
+int LZ4_compress_fast_extState(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration)
+{
+ LZ4_stream_t_internal* const ctx = & LZ4_initStream(state, sizeof(LZ4_stream_t)) -> internal_donotuse;
+ assert(ctx != NULL);
+ if (acceleration < 1) acceleration = LZ4_ACCELERATION_DEFAULT;
+ if (acceleration > LZ4_ACCELERATION_MAX) acceleration = LZ4_ACCELERATION_MAX;
+ if (maxOutputSize >= LZ4_compressBound(inputSize)) {
+ if (inputSize < LZ4_64Klimit) {
+ return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, 0, notLimited, byU16, noDict, noDictIssue, acceleration);
+ } else {
+ const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)source > LZ4_DISTANCE_MAX)) ? byPtr : byU32;
+ return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, 0, notLimited, tableType, noDict, noDictIssue, acceleration);
+ }
+ } else {
+ if (inputSize < LZ4_64Klimit) {
+ return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue, acceleration);
+ } else {
+ const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)source > LZ4_DISTANCE_MAX)) ? byPtr : byU32;
+ return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, noDict, noDictIssue, acceleration);
+ }
+ }
+}
+
+/**
+ * LZ4_compress_fast_extState_fastReset() :
+ * A variant of LZ4_compress_fast_extState().
+ *
+ * Using this variant avoids an expensive initialization step. It is only safe
+ * to call if the state buffer is known to be correctly initialized already
+ * (see comment in lz4.h on LZ4_resetStream_fast() for a definition of
+ * "correctly initialized").
+ */
+int LZ4_compress_fast_extState_fastReset(void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration)
+{
+ LZ4_stream_t_internal* ctx = &((LZ4_stream_t*)state)->internal_donotuse;
+ if (acceleration < 1) acceleration = LZ4_ACCELERATION_DEFAULT;
+ if (acceleration > LZ4_ACCELERATION_MAX) acceleration = LZ4_ACCELERATION_MAX;
+
+ if (dstCapacity >= LZ4_compressBound(srcSize)) {
+ if (srcSize < LZ4_64Klimit) {
+ const tableType_t tableType = byU16;
+ LZ4_prepareTable(ctx, srcSize, tableType);
+ if (ctx->currentOffset) {
+ return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 0, notLimited, tableType, noDict, dictSmall, acceleration);
+ } else {
+ return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 0, notLimited, tableType, noDict, noDictIssue, acceleration);
+ }
+ } else {
+ const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)src > LZ4_DISTANCE_MAX)) ? byPtr : byU32;
+ LZ4_prepareTable(ctx, srcSize, tableType);
+ return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 0, notLimited, tableType, noDict, noDictIssue, acceleration);
+ }
+ } else {
+ if (srcSize < LZ4_64Klimit) {
+ const tableType_t tableType = byU16;
+ LZ4_prepareTable(ctx, srcSize, tableType);
+ if (ctx->currentOffset) {
+ return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, dstCapacity, limitedOutput, tableType, noDict, dictSmall, acceleration);
+ } else {
+ return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, dstCapacity, limitedOutput, tableType, noDict, noDictIssue, acceleration);
+ }
+ } else {
+ const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)src > LZ4_DISTANCE_MAX)) ? byPtr : byU32;
+ LZ4_prepareTable(ctx, srcSize, tableType);
+ return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, dstCapacity, limitedOutput, tableType, noDict, noDictIssue, acceleration);
+ }
+ }
+}
+
+
+int LZ4_compress_fast(const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration)
+{
+ int result;
+#if (LZ4_HEAPMODE)
+ LZ4_stream_t* ctxPtr = ALLOC(sizeof(LZ4_stream_t)); /* malloc-calloc always properly aligned */
+ if (ctxPtr == NULL) return 0;
+#else
+ LZ4_stream_t ctx;
+ LZ4_stream_t* const ctxPtr = &ctx;
+#endif
+ result = LZ4_compress_fast_extState(ctxPtr, source, dest, inputSize, maxOutputSize, acceleration);
+
+#if (LZ4_HEAPMODE)
+ FREEMEM(ctxPtr);
+#endif
+ return result;
+}
+
+
+int LZ4_compress_default(const char* src, char* dst, int srcSize, int maxOutputSize)
+{
+ return LZ4_compress_fast(src, dst, srcSize, maxOutputSize, 1);
+}
+
+
+/* Note!: This function leaves the stream in an unclean/broken state!
+ * It is not safe to subsequently use the same state with a _fastReset() or
+ * _continue() call without resetting it. */
+static int LZ4_compress_destSize_extState (LZ4_stream_t* state, const char* src, char* dst, int* srcSizePtr, int targetDstSize)
+{
+ void* const s = LZ4_initStream(state, sizeof (*state));
+ assert(s != NULL); (void)s;
+
+ if (targetDstSize >= LZ4_compressBound(*srcSizePtr)) { /* compression success is guaranteed */
+ return LZ4_compress_fast_extState(state, src, dst, *srcSizePtr, targetDstSize, 1);
+ } else {
+ if (*srcSizePtr < LZ4_64Klimit) {
+ return LZ4_compress_generic(&state->internal_donotuse, src, dst, *srcSizePtr, srcSizePtr, targetDstSize, fillOutput, byU16, noDict, noDictIssue, 1);
+ } else {
+ tableType_t const addrMode = ((sizeof(void*)==4) && ((uptrval)src > LZ4_DISTANCE_MAX)) ? byPtr : byU32;
+ return LZ4_compress_generic(&state->internal_donotuse, src, dst, *srcSizePtr, srcSizePtr, targetDstSize, fillOutput, addrMode, noDict, noDictIssue, 1);
+ } }
+}
+
+
+int LZ4_compress_destSize(const char* src, char* dst, int* srcSizePtr, int targetDstSize)
+{
+#if (LZ4_HEAPMODE)
+ LZ4_stream_t* ctx = (LZ4_stream_t*)ALLOC(sizeof(LZ4_stream_t)); /* malloc-calloc always properly aligned */
+ if (ctx == NULL) return 0;
+#else
+ LZ4_stream_t ctxBody;
+ LZ4_stream_t* ctx = &ctxBody;
+#endif
+
+ int result = LZ4_compress_destSize_extState(ctx, src, dst, srcSizePtr, targetDstSize);
+
+#if (LZ4_HEAPMODE)
+ FREEMEM(ctx);
+#endif
+ return result;
+}
+
+
+
+/*-******************************
+* Streaming functions
+********************************/
+
+LZ4_stream_t* LZ4_createStream(void)
+{
+ LZ4_stream_t* const lz4s = (LZ4_stream_t*)ALLOC(sizeof(LZ4_stream_t));
+ LZ4_STATIC_ASSERT(LZ4_STREAMSIZE >= sizeof(LZ4_stream_t_internal)); /* A compilation error here means LZ4_STREAMSIZE is not large enough */
+ DEBUGLOG(4, "LZ4_createStream %p", lz4s);
+ if (lz4s == NULL) return NULL;
+ LZ4_initStream(lz4s, sizeof(*lz4s));
+ return lz4s;
+}
+
+static size_t LZ4_stream_t_alignment(void)
+{
+#if LZ4_ALIGN_TEST
+ typedef struct { char c; LZ4_stream_t t; } t_a;
+ return sizeof(t_a) - sizeof(LZ4_stream_t);
+#else
+ return 1; /* effectively disabled */
+#endif
+}
+
+LZ4_stream_t* LZ4_initStream (void* buffer, size_t size)
+{
+ DEBUGLOG(5, "LZ4_initStream");
+ if (buffer == NULL) { return NULL; }
+ if (size < sizeof(LZ4_stream_t)) { return NULL; }
+ if (!LZ4_isAligned(buffer, LZ4_stream_t_alignment())) return NULL;
+ MEM_INIT(buffer, 0, sizeof(LZ4_stream_t_internal));
+ return (LZ4_stream_t*)buffer;
+}
+
+/* resetStream is now deprecated,
+ * prefer initStream() which is more general */
+void LZ4_resetStream (LZ4_stream_t* LZ4_stream)
+{
+ DEBUGLOG(5, "LZ4_resetStream (ctx:%p)", LZ4_stream);
+ MEM_INIT(LZ4_stream, 0, sizeof(LZ4_stream_t_internal));
+}
+
+void LZ4_resetStream_fast(LZ4_stream_t* ctx) {
+ LZ4_prepareTable(&(ctx->internal_donotuse), 0, byU32);
+}
+
+int LZ4_freeStream (LZ4_stream_t* LZ4_stream)
+{
+ if (!LZ4_stream) return 0; /* support free on NULL */
+ DEBUGLOG(5, "LZ4_freeStream %p", LZ4_stream);
+ FREEMEM(LZ4_stream);
+ return (0);
+}
+
+
+#define HASH_UNIT sizeof(reg_t)
+int LZ4_loadDict (LZ4_stream_t* LZ4_dict, const char* dictionary, int dictSize)
+{
+ LZ4_stream_t_internal* dict = &LZ4_dict->internal_donotuse;
+ const tableType_t tableType = byU32;
+ const BYTE* p = (const BYTE*)dictionary;
+ const BYTE* const dictEnd = p + dictSize;
+ const BYTE* base;
+
+ DEBUGLOG(4, "LZ4_loadDict (%i bytes from %p into %p)", dictSize, dictionary, LZ4_dict);
+
+ /* It's necessary to reset the context,
+ * and not just continue it with prepareTable()
+ * to avoid any risk of generating overflowing matchIndex
+ * when compressing using this dictionary */
+ LZ4_resetStream(LZ4_dict);
+
+ /* We always increment the offset by 64 KB, since, if the dict is longer,
+ * we truncate it to the last 64k, and if it's shorter, we still want to
+ * advance by a whole window length so we can provide the guarantee that
+ * there are only valid offsets in the window, which allows an optimization
+ * in LZ4_compress_fast_continue() where it uses noDictIssue even when the
+ * dictionary isn't a full 64k. */
+ dict->currentOffset += 64 KB;
+
+ if (dictSize < (int)HASH_UNIT) {
+ return 0;
+ }
+
+ if ((dictEnd - p) > 64 KB) p = dictEnd - 64 KB;
+ base = dictEnd - dict->currentOffset;
+ dict->dictionary = p;
+ dict->dictSize = (U32)(dictEnd - p);
+ dict->tableType = (U32)tableType;
+
+ while (p <= dictEnd-HASH_UNIT) {
+ LZ4_putPosition(p, dict->hashTable, tableType, base);
+ p+=3;
+ }
+
+ return (int)dict->dictSize;
+}
+
+void LZ4_attach_dictionary(LZ4_stream_t* workingStream, const LZ4_stream_t* dictionaryStream) {
+ const LZ4_stream_t_internal* dictCtx = dictionaryStream == NULL ? NULL :
+ &(dictionaryStream->internal_donotuse);
+
+ DEBUGLOG(4, "LZ4_attach_dictionary (%p, %p, size %u)",
+ workingStream, dictionaryStream,
+ dictCtx != NULL ? dictCtx->dictSize : 0);
+
+ if (dictCtx != NULL) {
+ /* If the current offset is zero, we will never look in the
+ * external dictionary context, since there is no value a table
+ * entry can take that indicate a miss. In that case, we need
+ * to bump the offset to something non-zero.
+ */
+ if (workingStream->internal_donotuse.currentOffset == 0) {
+ workingStream->internal_donotuse.currentOffset = 64 KB;
+ }
+
+ /* Don't actually attach an empty dictionary.
+ */
+ if (dictCtx->dictSize == 0) {
+ dictCtx = NULL;
+ }
+ }
+ workingStream->internal_donotuse.dictCtx = dictCtx;
+}
+
+
+static void LZ4_renormDictT(LZ4_stream_t_internal* LZ4_dict, int nextSize)
+{
+ assert(nextSize >= 0);
+ if (LZ4_dict->currentOffset + (unsigned)nextSize > 0x80000000) { /* potential ptrdiff_t overflow (32-bits mode) */
+ /* rescale hash table */
+ U32 const delta = LZ4_dict->currentOffset - 64 KB;
+ const BYTE* dictEnd = LZ4_dict->dictionary + LZ4_dict->dictSize;
+ int i;
+ DEBUGLOG(4, "LZ4_renormDictT");
+ for (i=0; i<LZ4_HASH_SIZE_U32; i++) {
+ if (LZ4_dict->hashTable[i] < delta) LZ4_dict->hashTable[i]=0;
+ else LZ4_dict->hashTable[i] -= delta;
+ }
+ LZ4_dict->currentOffset = 64 KB;
+ if (LZ4_dict->dictSize > 64 KB) LZ4_dict->dictSize = 64 KB;
+ LZ4_dict->dictionary = dictEnd - LZ4_dict->dictSize;
+ }
+}
+
+
+int LZ4_compress_fast_continue (LZ4_stream_t* LZ4_stream,
+ const char* source, char* dest,
+ int inputSize, int maxOutputSize,
+ int acceleration)
+{
+ const tableType_t tableType = byU32;
+ LZ4_stream_t_internal* streamPtr = &LZ4_stream->internal_donotuse;
+ const BYTE* dictEnd = streamPtr->dictionary + streamPtr->dictSize;
+
+ DEBUGLOG(5, "LZ4_compress_fast_continue (inputSize=%i)", inputSize);
+
+ LZ4_renormDictT(streamPtr, inputSize); /* avoid index overflow */
+ if (acceleration < 1) acceleration = LZ4_ACCELERATION_DEFAULT;
+ if (acceleration > LZ4_ACCELERATION_MAX) acceleration = LZ4_ACCELERATION_MAX;
+
+ /* invalidate tiny dictionaries */
+ if ( (streamPtr->dictSize-1 < 4-1) /* intentional underflow */
+ && (dictEnd != (const BYTE*)source) ) {
+ DEBUGLOG(5, "LZ4_compress_fast_continue: dictSize(%u) at addr:%p is too small", streamPtr->dictSize, streamPtr->dictionary);
+ streamPtr->dictSize = 0;
+ streamPtr->dictionary = (const BYTE*)source;
+ dictEnd = (const BYTE*)source;
+ }
+
+ /* Check overlapping input/dictionary space */
+ { const BYTE* sourceEnd = (const BYTE*) source + inputSize;
+ if ((sourceEnd > streamPtr->dictionary) && (sourceEnd < dictEnd)) {
+ streamPtr->dictSize = (U32)(dictEnd - sourceEnd);
+ if (streamPtr->dictSize > 64 KB) streamPtr->dictSize = 64 KB;
+ if (streamPtr->dictSize < 4) streamPtr->dictSize = 0;
+ streamPtr->dictionary = dictEnd - streamPtr->dictSize;
+ }
+ }
+
+ /* prefix mode : source data follows dictionary */
+ if (dictEnd == (const BYTE*)source) {
+ if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset))
+ return LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, withPrefix64k, dictSmall, acceleration);
+ else
+ return LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, withPrefix64k, noDictIssue, acceleration);
+ }
+
+ /* external dictionary mode */
+ { int result;
+ if (streamPtr->dictCtx) {
+ /* We depend here on the fact that dictCtx'es (produced by
+ * LZ4_loadDict) guarantee that their tables contain no references
+ * to offsets between dictCtx->currentOffset - 64 KB and
+ * dictCtx->currentOffset - dictCtx->dictSize. This makes it safe
+ * to use noDictIssue even when the dict isn't a full 64 KB.
+ */
+ if (inputSize > 4 KB) {
+ /* For compressing large blobs, it is faster to pay the setup
+ * cost to copy the dictionary's tables into the active context,
+ * so that the compression loop is only looking into one table.
+ */
+ LZ4_memcpy(streamPtr, streamPtr->dictCtx, sizeof(*streamPtr));
+ result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingExtDict, noDictIssue, acceleration);
+ } else {
+ result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingDictCtx, noDictIssue, acceleration);
+ }
+ } else {
+ if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset)) {
+ result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingExtDict, dictSmall, acceleration);
+ } else {
+ result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingExtDict, noDictIssue, acceleration);
+ }
+ }
+ streamPtr->dictionary = (const BYTE*)source;
+ streamPtr->dictSize = (U32)inputSize;
+ return result;
+ }
+}
+
+
+/* Hidden debug function, to force-test external dictionary mode */
+int LZ4_compress_forceExtDict (LZ4_stream_t* LZ4_dict, const char* source, char* dest, int srcSize)
+{
+ LZ4_stream_t_internal* streamPtr = &LZ4_dict->internal_donotuse;
+ int result;
+
+ LZ4_renormDictT(streamPtr, srcSize);
+
+ if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset)) {
+ result = LZ4_compress_generic(streamPtr, source, dest, srcSize, NULL, 0, notLimited, byU32, usingExtDict, dictSmall, 1);
+ } else {
+ result = LZ4_compress_generic(streamPtr, source, dest, srcSize, NULL, 0, notLimited, byU32, usingExtDict, noDictIssue, 1);
+ }
+
+ streamPtr->dictionary = (const BYTE*)source;
+ streamPtr->dictSize = (U32)srcSize;
+
+ return result;
+}
+
+
+/*! LZ4_saveDict() :
+ * If previously compressed data block is not guaranteed to remain available at its memory location,
+ * save it into a safer place (char* safeBuffer).
+ * Note : you don't need to call LZ4_loadDict() afterwards,
+ * dictionary is immediately usable, you can therefore call LZ4_compress_fast_continue().
+ * Return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error.
+ */
+int LZ4_saveDict (LZ4_stream_t* LZ4_dict, char* safeBuffer, int dictSize)
+{
+ LZ4_stream_t_internal* const dict = &LZ4_dict->internal_donotuse;
+ const BYTE* const previousDictEnd = dict->dictionary + dict->dictSize;
+
+ if ((U32)dictSize > 64 KB) { dictSize = 64 KB; } /* useless to define a dictionary > 64 KB */
+ if ((U32)dictSize > dict->dictSize) { dictSize = (int)dict->dictSize; }
+
+ if (safeBuffer == NULL) assert(dictSize == 0);
+ if (dictSize > 0)
+ memmove(safeBuffer, previousDictEnd - dictSize, dictSize);
+
+ dict->dictionary = (const BYTE*)safeBuffer;
+ dict->dictSize = (U32)dictSize;
+
+ return dictSize;
+}
+
+
+
+/*-*******************************
+ * Decompression functions
+ ********************************/
+
+typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
+typedef enum { decode_full_block = 0, partial_decode = 1 } earlyEnd_directive;
+
+#undef MIN
+#define MIN(a,b) ( (a) < (b) ? (a) : (b) )
+
+/* Read the variable-length literal or match length.
+ *
+ * ip - pointer to use as input.
+ * lencheck - end ip. Return an error if ip advances >= lencheck.
+ * loop_check - check ip >= lencheck in body of loop. Returns loop_error if so.
+ * initial_check - check ip >= lencheck before start of loop. Returns initial_error if so.
+ * error (output) - error code. Should be set to 0 before call.
+ */
+typedef enum { loop_error = -2, initial_error = -1, ok = 0 } variable_length_error;
+LZ4_FORCE_INLINE unsigned
+read_variable_length(const BYTE**ip, const BYTE* lencheck,
+ int loop_check, int initial_check,
+ variable_length_error* error)
+{
+ U32 length = 0;
+ U32 s;
+ if (initial_check && unlikely((*ip) >= lencheck)) { /* overflow detection */
+ *error = initial_error;
+ return length;
+ }
+ do {
+ s = **ip;
+ (*ip)++;
+ length += s;
+ if (loop_check && unlikely((*ip) >= lencheck)) { /* overflow detection */
+ *error = loop_error;
+ return length;
+ }
+ } while (s==255);
+
+ return length;
+}
+
+/*! LZ4_decompress_generic() :
+ * This generic decompression function covers all use cases.
+ * It shall be instantiated several times, using different sets of directives.
+ * Note that it is important for performance that this function really get inlined,
+ * in order to remove useless branches during compilation optimization.
+ */
+LZ4_FORCE_INLINE int
+LZ4_decompress_generic(
+ const char* const src,
+ char* const dst,
+ int srcSize,
+ int outputSize, /* If endOnInput==endOnInputSize, this value is `dstCapacity` */
+
+ endCondition_directive endOnInput, /* endOnOutputSize, endOnInputSize */
+ earlyEnd_directive partialDecoding, /* full, partial */
+ dict_directive dict, /* noDict, withPrefix64k, usingExtDict */
+ const BYTE* const lowPrefix, /* always <= dst, == dst when no prefix */
+ const BYTE* const dictStart, /* only if dict==usingExtDict */
+ const size_t dictSize /* note : = 0 if noDict */
+ )
+{
+ if (src == NULL) { return -1; }
+
+ { const BYTE* ip = (const BYTE*) src;
+ const BYTE* const iend = ip + srcSize;
+
+ BYTE* op = (BYTE*) dst;
+ BYTE* const oend = op + outputSize;
+ BYTE* cpy;
+
+ const BYTE* const dictEnd = (dictStart == NULL) ? NULL : dictStart + dictSize;
+
+ const int safeDecode = (endOnInput==endOnInputSize);
+ const int checkOffset = ((safeDecode) && (dictSize < (int)(64 KB)));
+
+
+ /* Set up the "end" pointers for the shortcut. */
+ const BYTE* const shortiend = iend - (endOnInput ? 14 : 8) /*maxLL*/ - 2 /*offset*/;
+ const BYTE* const shortoend = oend - (endOnInput ? 14 : 8) /*maxLL*/ - 18 /*maxML*/;
+
+ const BYTE* match;
+ size_t offset;
+ unsigned token;
+ size_t length;
+
+
+ DEBUGLOG(5, "LZ4_decompress_generic (srcSize:%i, dstSize:%i)", srcSize, outputSize);
+
+ /* Special cases */
+ assert(lowPrefix <= op);
+ if ((endOnInput) && (unlikely(outputSize==0))) {
+ /* Empty output buffer */
+ if (partialDecoding) return 0;
+ return ((srcSize==1) && (*ip==0)) ? 0 : -1;
+ }
+ if ((!endOnInput) && (unlikely(outputSize==0))) { return (*ip==0 ? 1 : -1); }
+ if ((endOnInput) && unlikely(srcSize==0)) { return -1; }
+
+ /* Currently the fast loop shows a regression on qualcomm arm chips. */
+#if LZ4_FAST_DEC_LOOP
+ if ((oend - op) < FASTLOOP_SAFE_DISTANCE) {
+ DEBUGLOG(6, "skip fast decode loop");
+ goto safe_decode;
+ }
+
+ /* Fast loop : decode sequences as long as output < iend-FASTLOOP_SAFE_DISTANCE */
+ while (1) {
+ /* Main fastloop assertion: We can always wildcopy FASTLOOP_SAFE_DISTANCE */
+ assert(oend - op >= FASTLOOP_SAFE_DISTANCE);
+ if (endOnInput) { assert(ip < iend); }
+ token = *ip++;
+ length = token >> ML_BITS; /* literal length */
+
+ assert(!endOnInput || ip <= iend); /* ip < iend before the increment */
+
+ /* decode literal length */
+ if (length == RUN_MASK) {
+ variable_length_error error = ok;
+ length += read_variable_length(&ip, iend-RUN_MASK, (int)endOnInput, (int)endOnInput, &error);
+ if (error == initial_error) { goto _output_error; }
+ if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)(op))) { goto _output_error; } /* overflow detection */
+ if ((safeDecode) && unlikely((uptrval)(ip)+length<(uptrval)(ip))) { goto _output_error; } /* overflow detection */
+
+ /* copy literals */
+ cpy = op+length;
+ LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH);
+ if (endOnInput) { /* LZ4_decompress_safe() */
+ if ((cpy>oend-32) || (ip+length>iend-32)) { goto safe_literal_copy; }
+ LZ4_wildCopy32(op, ip, cpy);
+ } else { /* LZ4_decompress_fast() */
+ if (cpy>oend-8) { goto safe_literal_copy; }
+ LZ4_wildCopy8(op, ip, cpy); /* LZ4_decompress_fast() cannot copy more than 8 bytes at a time :
+ * it doesn't know input length, and only relies on end-of-block properties */
+ }
+ ip += length; op = cpy;
+ } else {
+ cpy = op+length;
+ if (endOnInput) { /* LZ4_decompress_safe() */
+ DEBUGLOG(7, "copy %u bytes in a 16-bytes stripe", (unsigned)length);
+ /* We don't need to check oend, since we check it once for each loop below */
+ if (ip > iend-(16 + 1/*max lit + offset + nextToken*/)) { goto safe_literal_copy; }
+ /* Literals can only be 14, but hope compilers optimize if we copy by a register size */
+ LZ4_memcpy(op, ip, 16);
+ } else { /* LZ4_decompress_fast() */
+ /* LZ4_decompress_fast() cannot copy more than 8 bytes at a time :
+ * it doesn't know input length, and relies on end-of-block properties */
+ LZ4_memcpy(op, ip, 8);
+ if (length > 8) { LZ4_memcpy(op+8, ip+8, 8); }
+ }
+ ip += length; op = cpy;
+ }
+
+ /* get offset */
+ offset = LZ4_readLE16(ip); ip+=2;
+ match = op - offset;
+ assert(match <= op);
+
+ /* get matchlength */
+ length = token & ML_MASK;
+
+ if (length == ML_MASK) {
+ variable_length_error error = ok;
+ if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) { goto _output_error; } /* Error : offset outside buffers */
+ length += read_variable_length(&ip, iend - LASTLITERALS + 1, (int)endOnInput, 0, &error);
+ if (error != ok) { goto _output_error; }
+ if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)op)) { goto _output_error; } /* overflow detection */
+ length += MINMATCH;
+ if (op + length >= oend - FASTLOOP_SAFE_DISTANCE) {
+ goto safe_match_copy;
+ }
+ } else {
+ length += MINMATCH;
+ if (op + length >= oend - FASTLOOP_SAFE_DISTANCE) {
+ goto safe_match_copy;
+ }
+
+ /* Fastpath check: Avoids a branch in LZ4_wildCopy32 if true */
+ if ((dict == withPrefix64k) || (match >= lowPrefix)) {
+ if (offset >= 8) {
+ assert(match >= lowPrefix);
+ assert(match <= op);
+ assert(op + 18 <= oend);
+
+ LZ4_memcpy(op, match, 8);
+ LZ4_memcpy(op+8, match+8, 8);
+ LZ4_memcpy(op+16, match+16, 2);
+ op += length;
+ continue;
+ } } }
+
+ if (checkOffset && (unlikely(match + dictSize < lowPrefix))) { goto _output_error; } /* Error : offset outside buffers */
+ /* match starting within external dictionary */
+ if ((dict==usingExtDict) && (match < lowPrefix)) {
+ if (unlikely(op+length > oend-LASTLITERALS)) {
+ if (partialDecoding) {
+ DEBUGLOG(7, "partialDecoding: dictionary match, close to dstEnd");
+ length = MIN(length, (size_t)(oend-op));
+ } else {
+ goto _output_error; /* end-of-block condition violated */
+ } }
+
+ if (length <= (size_t)(lowPrefix-match)) {
+ /* match fits entirely within external dictionary : just copy */
+ memmove(op, dictEnd - (lowPrefix-match), length);
+ op += length;
+ } else {
+ /* match stretches into both external dictionary and current block */
+ size_t const copySize = (size_t)(lowPrefix - match);
+ size_t const restSize = length - copySize;
+ LZ4_memcpy(op, dictEnd - copySize, copySize);
+ op += copySize;
+ if (restSize > (size_t)(op - lowPrefix)) { /* overlap copy */
+ BYTE* const endOfMatch = op + restSize;
+ const BYTE* copyFrom = lowPrefix;
+ while (op < endOfMatch) { *op++ = *copyFrom++; }
+ } else {
+ LZ4_memcpy(op, lowPrefix, restSize);
+ op += restSize;
+ } }
+ continue;
+ }
+
+ /* copy match within block */
+ cpy = op + length;
+
+ assert((op <= oend) && (oend-op >= 32));
+ if (unlikely(offset<16)) {
+ LZ4_memcpy_using_offset(op, match, cpy, offset);
+ } else {
+ LZ4_wildCopy32(op, match, cpy);
+ }
+
+ op = cpy; /* wildcopy correction */
+ }
+ safe_decode:
+#endif
+
+ /* Main Loop : decode remaining sequences where output < FASTLOOP_SAFE_DISTANCE */
+ while (1) {
+ token = *ip++;
+ length = token >> ML_BITS; /* literal length */
+
+ assert(!endOnInput || ip <= iend); /* ip < iend before the increment */
+
+ /* A two-stage shortcut for the most common case:
+ * 1) If the literal length is 0..14, and there is enough space,
+ * enter the shortcut and copy 16 bytes on behalf of the literals
+ * (in the fast mode, only 8 bytes can be safely copied this way).
+ * 2) Further if the match length is 4..18, copy 18 bytes in a similar
+ * manner; but we ensure that there's enough space in the output for
+ * those 18 bytes earlier, upon entering the shortcut (in other words,
+ * there is a combined check for both stages).
+ */
+ if ( (endOnInput ? length != RUN_MASK : length <= 8)
+ /* strictly "less than" on input, to re-enter the loop with at least one byte */
+ && likely((endOnInput ? ip < shortiend : 1) & (op <= shortoend)) ) {
+ /* Copy the literals */
+ LZ4_memcpy(op, ip, endOnInput ? 16 : 8);
+ op += length; ip += length;
+
+ /* The second stage: prepare for match copying, decode full info.
+ * If it doesn't work out, the info won't be wasted. */
+ length = token & ML_MASK; /* match length */
+ offset = LZ4_readLE16(ip); ip += 2;
+ match = op - offset;
+ assert(match <= op); /* check overflow */
+
+ /* Do not deal with overlapping matches. */
+ if ( (length != ML_MASK)
+ && (offset >= 8)
+ && (dict==withPrefix64k || match >= lowPrefix) ) {
+ /* Copy the match. */
+ LZ4_memcpy(op + 0, match + 0, 8);
+ LZ4_memcpy(op + 8, match + 8, 8);
+ LZ4_memcpy(op +16, match +16, 2);
+ op += length + MINMATCH;
+ /* Both stages worked, load the next token. */
+ continue;
+ }
+
+ /* The second stage didn't work out, but the info is ready.
+ * Propel it right to the point of match copying. */
+ goto _copy_match;
+ }
+
+ /* decode literal length */
+ if (length == RUN_MASK) {
+ variable_length_error error = ok;
+ length += read_variable_length(&ip, iend-RUN_MASK, (int)endOnInput, (int)endOnInput, &error);
+ if (error == initial_error) { goto _output_error; }
+ if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)(op))) { goto _output_error; } /* overflow detection */
+ if ((safeDecode) && unlikely((uptrval)(ip)+length<(uptrval)(ip))) { goto _output_error; } /* overflow detection */
+ }
+
+ /* copy literals */
+ cpy = op+length;
+#if LZ4_FAST_DEC_LOOP
+ safe_literal_copy:
+#endif
+ LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH);
+ if ( ((endOnInput) && ((cpy>oend-MFLIMIT) || (ip+length>iend-(2+1+LASTLITERALS))) )
+ || ((!endOnInput) && (cpy>oend-WILDCOPYLENGTH)) )
+ {
+ /* We've either hit the input parsing restriction or the output parsing restriction.
+ * In the normal scenario, decoding a full block, it must be the last sequence,
+ * otherwise it's an error (invalid input or dimensions).
+ * In partialDecoding scenario, it's necessary to ensure there is no buffer overflow.
+ */
+ if (partialDecoding) {
+ /* Since we are partial decoding we may be in this block because of the output parsing
+ * restriction, which is not valid since the output buffer is allowed to be undersized.
+ */
+ assert(endOnInput);
+ DEBUGLOG(7, "partialDecoding: copying literals, close to input or output end")
+ DEBUGLOG(7, "partialDecoding: literal length = %u", (unsigned)length);
+ DEBUGLOG(7, "partialDecoding: remaining space in dstBuffer : %i", (int)(oend - op));
+ DEBUGLOG(7, "partialDecoding: remaining space in srcBuffer : %i", (int)(iend - ip));
+ /* Finishing in the middle of a literals segment,
+ * due to lack of input.
+ */
+ if (ip+length > iend) {
+ length = (size_t)(iend-ip);
+ cpy = op + length;
+ }
+ /* Finishing in the middle of a literals segment,
+ * due to lack of output space.
+ */
+ if (cpy > oend) {
+ cpy = oend;
+ assert(op<=oend);
+ length = (size_t)(oend-op);
+ }
+ } else {
+ /* We must be on the last sequence because of the parsing limitations so check
+ * that we exactly regenerate the original size (must be exact when !endOnInput).
+ */
+ if ((!endOnInput) && (cpy != oend)) { goto _output_error; }
+ /* We must be on the last sequence (or invalid) because of the parsing limitations
+ * so check that we exactly consume the input and don't overrun the output buffer.
+ */
+ if ((endOnInput) && ((ip+length != iend) || (cpy > oend))) {
+ DEBUGLOG(6, "should have been last run of literals")
+ DEBUGLOG(6, "ip(%p) + length(%i) = %p != iend (%p)", ip, (int)length, ip+length, iend);
+ DEBUGLOG(6, "or cpy(%p) > oend(%p)", cpy, oend);
+ goto _output_error;
+ }
+ }
+ memmove(op, ip, length); /* supports overlapping memory regions; only matters for in-place decompression scenarios */
+ ip += length;
+ op += length;
+ /* Necessarily EOF when !partialDecoding.
+ * When partialDecoding, it is EOF if we've either
+ * filled the output buffer or
+ * can't proceed with reading an offset for following match.
+ */
+ if (!partialDecoding || (cpy == oend) || (ip >= (iend-2))) {
+ break;
+ }
+ } else {
+ LZ4_wildCopy8(op, ip, cpy); /* may overwrite up to WILDCOPYLENGTH beyond cpy */
+ ip += length; op = cpy;
+ }
+
+ /* get offset */
+ offset = LZ4_readLE16(ip); ip+=2;
+ match = op - offset;
+
+ /* get matchlength */
+ length = token & ML_MASK;
+
+ _copy_match:
+ if (length == ML_MASK) {
+ variable_length_error error = ok;
+ length += read_variable_length(&ip, iend - LASTLITERALS + 1, (int)endOnInput, 0, &error);
+ if (error != ok) goto _output_error;
+ if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)op)) goto _output_error; /* overflow detection */
+ }
+ length += MINMATCH;
+
+#if LZ4_FAST_DEC_LOOP
+ safe_match_copy:
+#endif
+ if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) goto _output_error; /* Error : offset outside buffers */
+ /* match starting within external dictionary */
+ if ((dict==usingExtDict) && (match < lowPrefix)) {
+ if (unlikely(op+length > oend-LASTLITERALS)) {
+ if (partialDecoding) length = MIN(length, (size_t)(oend-op));
+ else goto _output_error; /* doesn't respect parsing restriction */
+ }
+
+ if (length <= (size_t)(lowPrefix-match)) {
+ /* match fits entirely within external dictionary : just copy */
+ memmove(op, dictEnd - (lowPrefix-match), length);
+ op += length;
+ } else {
+ /* match stretches into both external dictionary and current block */
+ size_t const copySize = (size_t)(lowPrefix - match);
+ size_t const restSize = length - copySize;
+ LZ4_memcpy(op, dictEnd - copySize, copySize);
+ op += copySize;
+ if (restSize > (size_t)(op - lowPrefix)) { /* overlap copy */
+ BYTE* const endOfMatch = op + restSize;
+ const BYTE* copyFrom = lowPrefix;
+ while (op < endOfMatch) *op++ = *copyFrom++;
+ } else {
+ LZ4_memcpy(op, lowPrefix, restSize);
+ op += restSize;
+ } }
+ continue;
+ }
+ assert(match >= lowPrefix);
+
+ /* copy match within block */
+ cpy = op + length;
+
+ /* partialDecoding : may end anywhere within the block */
+ assert(op<=oend);
+ if (partialDecoding && (cpy > oend-MATCH_SAFEGUARD_DISTANCE)) {
+ size_t const mlen = MIN(length, (size_t)(oend-op));
+ const BYTE* const matchEnd = match + mlen;
+ BYTE* const copyEnd = op + mlen;
+ if (matchEnd > op) { /* overlap copy */
+ while (op < copyEnd) { *op++ = *match++; }
+ } else {
+ LZ4_memcpy(op, match, mlen);
+ }
+ op = copyEnd;
+ if (op == oend) { break; }
+ continue;
+ }
+
+ if (unlikely(offset<8)) {
+ LZ4_write32(op, 0); /* silence msan warning when offset==0 */
+ op[0] = match[0];
+ op[1] = match[1];
+ op[2] = match[2];
+ op[3] = match[3];
+ match += inc32table[offset];
+ LZ4_memcpy(op+4, match, 4);
+ match -= dec64table[offset];
+ } else {
+ LZ4_memcpy(op, match, 8);
+ match += 8;
+ }
+ op += 8;
+
+ if (unlikely(cpy > oend-MATCH_SAFEGUARD_DISTANCE)) {
+ BYTE* const oCopyLimit = oend - (WILDCOPYLENGTH-1);
+ if (cpy > oend-LASTLITERALS) { goto _output_error; } /* Error : last LASTLITERALS bytes must be literals (uncompressed) */
+ if (op < oCopyLimit) {
+ LZ4_wildCopy8(op, match, oCopyLimit);
+ match += oCopyLimit - op;
+ op = oCopyLimit;
+ }
+ while (op < cpy) { *op++ = *match++; }
+ } else {
+ LZ4_memcpy(op, match, 8);
+ if (length > 16) { LZ4_wildCopy8(op+8, match+8, cpy); }
+ }
+ op = cpy; /* wildcopy correction */
+ }
+
+ /* end of decoding */
+ if (endOnInput) {
+ DEBUGLOG(5, "decoded %i bytes", (int) (((char*)op)-dst));
+ return (int) (((char*)op)-dst); /* Nb of output bytes decoded */
+ } else {
+ return (int) (((const char*)ip)-src); /* Nb of input bytes read */
+ }
+
+ /* Overflow error detected */
+ _output_error:
+ return (int) (-(((const char*)ip)-src))-1;
+ }
+}
+
+
+/*===== Instantiate the API decoding functions. =====*/
+
+LZ4_FORCE_O2
+int LZ4_decompress_safe(const char* source, char* dest, int compressedSize, int maxDecompressedSize)
+{
+ return LZ4_decompress_generic(source, dest, compressedSize, maxDecompressedSize,
+ endOnInputSize, decode_full_block, noDict,
+ (BYTE*)dest, NULL, 0);
+}
+
+LZ4_FORCE_O2
+int LZ4_decompress_safe_partial(const char* src, char* dst, int compressedSize, int targetOutputSize, int dstCapacity)
+{
+ dstCapacity = MIN(targetOutputSize, dstCapacity);
+ return LZ4_decompress_generic(src, dst, compressedSize, dstCapacity,
+ endOnInputSize, partial_decode,
+ noDict, (BYTE*)dst, NULL, 0);
+}
+
+LZ4_FORCE_O2
+int LZ4_decompress_fast(const char* source, char* dest, int originalSize)
+{
+ return LZ4_decompress_generic(source, dest, 0, originalSize,
+ endOnOutputSize, decode_full_block, withPrefix64k,
+ (BYTE*)dest - 64 KB, NULL, 0);
+}
+
+/*===== Instantiate a few more decoding cases, used more than once. =====*/
+
+LZ4_FORCE_O2 /* Exported, an obsolete API function. */
+int LZ4_decompress_safe_withPrefix64k(const char* source, char* dest, int compressedSize, int maxOutputSize)
+{
+ return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
+ endOnInputSize, decode_full_block, withPrefix64k,
+ (BYTE*)dest - 64 KB, NULL, 0);
+}
+
+/* Another obsolete API function, paired with the previous one. */
+int LZ4_decompress_fast_withPrefix64k(const char* source, char* dest, int originalSize)
+{
+ /* LZ4_decompress_fast doesn't validate match offsets,
+ * and thus serves well with any prefixed dictionary. */
+ return LZ4_decompress_fast(source, dest, originalSize);
+}
+
+LZ4_FORCE_O2
+static int LZ4_decompress_safe_withSmallPrefix(const char* source, char* dest, int compressedSize, int maxOutputSize,
+ size_t prefixSize)
+{
+ return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
+ endOnInputSize, decode_full_block, noDict,
+ (BYTE*)dest-prefixSize, NULL, 0);
+}
+
+LZ4_FORCE_O2
+int LZ4_decompress_safe_forceExtDict(const char* source, char* dest,
+ int compressedSize, int maxOutputSize,
+ const void* dictStart, size_t dictSize)
+{
+ return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
+ endOnInputSize, decode_full_block, usingExtDict,
+ (BYTE*)dest, (const BYTE*)dictStart, dictSize);
+}
+
+LZ4_FORCE_O2
+static int LZ4_decompress_fast_extDict(const char* source, char* dest, int originalSize,
+ const void* dictStart, size_t dictSize)
+{
+ return LZ4_decompress_generic(source, dest, 0, originalSize,
+ endOnOutputSize, decode_full_block, usingExtDict,
+ (BYTE*)dest, (const BYTE*)dictStart, dictSize);
+}
+
+/* The "double dictionary" mode, for use with e.g. ring buffers: the first part
+ * of the dictionary is passed as prefix, and the second via dictStart + dictSize.
+ * These routines are used only once, in LZ4_decompress_*_continue().
+ */
+LZ4_FORCE_INLINE
+int LZ4_decompress_safe_doubleDict(const char* source, char* dest, int compressedSize, int maxOutputSize,
+ size_t prefixSize, const void* dictStart, size_t dictSize)
+{
+ return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
+ endOnInputSize, decode_full_block, usingExtDict,
+ (BYTE*)dest-prefixSize, (const BYTE*)dictStart, dictSize);
+}
+
+LZ4_FORCE_INLINE
+int LZ4_decompress_fast_doubleDict(const char* source, char* dest, int originalSize,
+ size_t prefixSize, const void* dictStart, size_t dictSize)
+{
+ return LZ4_decompress_generic(source, dest, 0, originalSize,
+ endOnOutputSize, decode_full_block, usingExtDict,
+ (BYTE*)dest-prefixSize, (const BYTE*)dictStart, dictSize);
+}
+
+/*===== streaming decompression functions =====*/
+
+LZ4_streamDecode_t* LZ4_createStreamDecode(void)
+{
+ LZ4_streamDecode_t* lz4s = (LZ4_streamDecode_t*) ALLOC_AND_ZERO(sizeof(LZ4_streamDecode_t));
+ LZ4_STATIC_ASSERT(LZ4_STREAMDECODESIZE >= sizeof(LZ4_streamDecode_t_internal)); /* A compilation error here means LZ4_STREAMDECODESIZE is not large enough */
+ return lz4s;
+}
+
+int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream)
+{
+ if (LZ4_stream == NULL) { return 0; } /* support free on NULL */
+ FREEMEM(LZ4_stream);
+ return 0;
+}
+
+/*! LZ4_setStreamDecode() :
+ * Use this function to instruct where to find the dictionary.
+ * This function is not necessary if previous data is still available where it was decoded.
+ * Loading a size of 0 is allowed (same effect as no dictionary).
+ * @return : 1 if OK, 0 if error
+ */
+int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize)
+{
+ LZ4_streamDecode_t_internal* lz4sd = &LZ4_streamDecode->internal_donotuse;
+ lz4sd->prefixSize = (size_t) dictSize;
+ lz4sd->prefixEnd = (const BYTE*) dictionary + dictSize;
+ lz4sd->externalDict = NULL;
+ lz4sd->extDictSize = 0;
+ return 1;
+}
+
+/*! LZ4_decoderRingBufferSize() :
+ * when setting a ring buffer for streaming decompression (optional scenario),
+ * provides the minimum size of this ring buffer
+ * to be compatible with any source respecting maxBlockSize condition.
+ * Note : in a ring buffer scenario,
+ * blocks are presumed decompressed next to each other.
+ * When not enough space remains for next block (remainingSize < maxBlockSize),
+ * decoding resumes from beginning of ring buffer.
+ * @return : minimum ring buffer size,
+ * or 0 if there is an error (invalid maxBlockSize).
+ */
+int LZ4_decoderRingBufferSize(int maxBlockSize)
+{
+ if (maxBlockSize < 0) return 0;
+ if (maxBlockSize > LZ4_MAX_INPUT_SIZE) return 0;
+ if (maxBlockSize < 16) maxBlockSize = 16;
+ return LZ4_DECODER_RING_BUFFER_SIZE(maxBlockSize);
+}
+
+/*
+*_continue() :
+ These decoding functions allow decompression of multiple blocks in "streaming" mode.
+ Previously decoded blocks must still be available at the memory position where they were decoded.
+ If it's not possible, save the relevant part of decoded data into a safe buffer,
+ and indicate where it stands using LZ4_setStreamDecode()
+*/
+LZ4_FORCE_O2
+int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxOutputSize)
+{
+ LZ4_streamDecode_t_internal* lz4sd = &LZ4_streamDecode->internal_donotuse;
+ int result;
+
+ if (lz4sd->prefixSize == 0) {
+ /* The first call, no dictionary yet. */
+ assert(lz4sd->extDictSize == 0);
+ result = LZ4_decompress_safe(source, dest, compressedSize, maxOutputSize);
+ if (result <= 0) return result;
+ lz4sd->prefixSize = (size_t)result;
+ lz4sd->prefixEnd = (BYTE*)dest + result;
+ } else if (lz4sd->prefixEnd == (BYTE*)dest) {
+ /* They're rolling the current segment. */
+ if (lz4sd->prefixSize >= 64 KB - 1)
+ result = LZ4_decompress_safe_withPrefix64k(source, dest, compressedSize, maxOutputSize);
+ else if (lz4sd->extDictSize == 0)
+ result = LZ4_decompress_safe_withSmallPrefix(source, dest, compressedSize, maxOutputSize,
+ lz4sd->prefixSize);
+ else
+ result = LZ4_decompress_safe_doubleDict(source, dest, compressedSize, maxOutputSize,
+ lz4sd->prefixSize, lz4sd->externalDict, lz4sd->extDictSize);
+ if (result <= 0) return result;
+ lz4sd->prefixSize += (size_t)result;
+ lz4sd->prefixEnd += result;
+ } else {
+ /* The buffer wraps around, or they're switching to another buffer. */
+ lz4sd->extDictSize = lz4sd->prefixSize;
+ lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize;
+ result = LZ4_decompress_safe_forceExtDict(source, dest, compressedSize, maxOutputSize,
+ lz4sd->externalDict, lz4sd->extDictSize);
+ if (result <= 0) return result;
+ lz4sd->prefixSize = (size_t)result;
+ lz4sd->prefixEnd = (BYTE*)dest + result;
+ }
+
+ return result;
+}
+
+LZ4_FORCE_O2
+int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int originalSize)
+{
+ LZ4_streamDecode_t_internal* lz4sd = &LZ4_streamDecode->internal_donotuse;
+ int result;
+ assert(originalSize >= 0);
+
+ if (lz4sd->prefixSize == 0) {
+ assert(lz4sd->extDictSize == 0);
+ result = LZ4_decompress_fast(source, dest, originalSize);
+ if (result <= 0) return result;
+ lz4sd->prefixSize = (size_t)originalSize;
+ lz4sd->prefixEnd = (BYTE*)dest + originalSize;
+ } else if (lz4sd->prefixEnd == (BYTE*)dest) {
+ if (lz4sd->prefixSize >= 64 KB - 1 || lz4sd->extDictSize == 0)
+ result = LZ4_decompress_fast(source, dest, originalSize);
+ else
+ result = LZ4_decompress_fast_doubleDict(source, dest, originalSize,
+ lz4sd->prefixSize, lz4sd->externalDict, lz4sd->extDictSize);
+ if (result <= 0) return result;
+ lz4sd->prefixSize += (size_t)originalSize;
+ lz4sd->prefixEnd += originalSize;
+ } else {
+ lz4sd->extDictSize = lz4sd->prefixSize;
+ lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize;
+ result = LZ4_decompress_fast_extDict(source, dest, originalSize,
+ lz4sd->externalDict, lz4sd->extDictSize);
+ if (result <= 0) return result;
+ lz4sd->prefixSize = (size_t)originalSize;
+ lz4sd->prefixEnd = (BYTE*)dest + originalSize;
+ }
+
+ return result;
+}
+
+
+/*
+Advanced decoding functions :
+*_usingDict() :
+ These decoding functions work the same as "_continue" ones,
+ the dictionary must be explicitly provided within parameters
+*/
+
+int LZ4_decompress_safe_usingDict(const char* source, char* dest, int compressedSize, int maxOutputSize, const char* dictStart, int dictSize)
+{
+ if (dictSize==0)
+ return LZ4_decompress_safe(source, dest, compressedSize, maxOutputSize);
+ if (dictStart+dictSize == dest) {
+ if (dictSize >= 64 KB - 1) {
+ return LZ4_decompress_safe_withPrefix64k(source, dest, compressedSize, maxOutputSize);
+ }
+ assert(dictSize >= 0);
+ return LZ4_decompress_safe_withSmallPrefix(source, dest, compressedSize, maxOutputSize, (size_t)dictSize);
+ }
+ assert(dictSize >= 0);
+ return LZ4_decompress_safe_forceExtDict(source, dest, compressedSize, maxOutputSize, dictStart, (size_t)dictSize);
+}
+
+int LZ4_decompress_fast_usingDict(const char* source, char* dest, int originalSize, const char* dictStart, int dictSize)
+{
+ if (dictSize==0 || dictStart+dictSize == dest)
+ return LZ4_decompress_fast(source, dest, originalSize);
+ assert(dictSize >= 0);
+ return LZ4_decompress_fast_extDict(source, dest, originalSize, dictStart, (size_t)dictSize);
+}
+
+
+/*=*************************************************
+* Obsolete Functions
+***************************************************/
+/* obsolete compression functions */
+int LZ4_compress_limitedOutput(const char* source, char* dest, int inputSize, int maxOutputSize)
+{
+ return LZ4_compress_default(source, dest, inputSize, maxOutputSize);
+}
+int LZ4_compress(const char* src, char* dest, int srcSize)
+{
+ return LZ4_compress_default(src, dest, srcSize, LZ4_compressBound(srcSize));
+}
+int LZ4_compress_limitedOutput_withState (void* state, const char* src, char* dst, int srcSize, int dstSize)
+{
+ return LZ4_compress_fast_extState(state, src, dst, srcSize, dstSize, 1);
+}
+int LZ4_compress_withState (void* state, const char* src, char* dst, int srcSize)
+{
+ return LZ4_compress_fast_extState(state, src, dst, srcSize, LZ4_compressBound(srcSize), 1);
+}
+int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_stream, const char* src, char* dst, int srcSize, int dstCapacity)
+{
+ return LZ4_compress_fast_continue(LZ4_stream, src, dst, srcSize, dstCapacity, 1);
+}
+int LZ4_compress_continue (LZ4_stream_t* LZ4_stream, const char* source, char* dest, int inputSize)
+{
+ return LZ4_compress_fast_continue(LZ4_stream, source, dest, inputSize, LZ4_compressBound(inputSize), 1);
+}
+
+/*
+These decompression functions are deprecated and should no longer be used.
+They are only provided here for compatibility with older user programs.
+- LZ4_uncompress is totally equivalent to LZ4_decompress_fast
+- LZ4_uncompress_unknownOutputSize is totally equivalent to LZ4_decompress_safe
+*/
+int LZ4_uncompress (const char* source, char* dest, int outputSize)
+{
+ return LZ4_decompress_fast(source, dest, outputSize);
+}
+int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize)
+{
+ return LZ4_decompress_safe(source, dest, isize, maxOutputSize);
+}
+
+/* Obsolete Streaming functions */
+
+int LZ4_sizeofStreamState(void) { return LZ4_STREAMSIZE; }
+
+int LZ4_resetStreamState(void* state, char* inputBuffer)
+{
+ (void)inputBuffer;
+ LZ4_resetStream((LZ4_stream_t*)state);
+ return 0;
+}
+
+void* LZ4_create (char* inputBuffer)
+{
+ (void)inputBuffer;
+ return LZ4_createStream();
+}
+
+char* LZ4_slideInputBuffer (void* state)
+{
+ /* avoid const char * -> char * conversion warning */
+ return (char *)(uptrval)((LZ4_stream_t*)state)->internal_donotuse.dictionary;
+}
+
+#endif /* LZ4_COMMONDEFS_ONLY */