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authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-12-27 11:44:20 +0100
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-12-28 16:15:35 +0100
commit113b174c5807f76cb14cfed7a8f86a299393666e (patch)
tree5049d9bf32dbc582c5da0f251e7fdfcfe817c2f4 /lib/sqfs/comp
parent2e109625bb7496bf1f3e75e30345c8cbd6eacede (diff)
Add a small version of liblz4 that can be built in statically
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'lib/sqfs/comp')
-rw-r--r--lib/sqfs/comp/lz4/README12
-rw-r--r--lib/sqfs/comp/lz4/lz4.c1708
-rw-r--r--lib/sqfs/comp/lz4/lz4.h341
-rw-r--r--lib/sqfs/comp/lz4/lz4hc.c1343
-rw-r--r--lib/sqfs/comp/lz4/lz4hc.h307
5 files changed, 3711 insertions, 0 deletions
diff --git a/lib/sqfs/comp/lz4/README b/lib/sqfs/comp/lz4/README
new file mode 100644
index 0000000..4c15347
--- /dev/null
+++ b/lib/sqfs/comp/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/sqfs/comp/lz4/lz4.c b/lib/sqfs/comp/lz4/lz4.c
new file mode 100644
index 0000000..853d228
--- /dev/null
+++ b/lib/sqfs/comp/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/sqfs/comp/lz4/lz4.h b/lib/sqfs/comp/lz4/lz4.h
new file mode 100644
index 0000000..43d3b14
--- /dev/null
+++ b/lib/sqfs/comp/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/sqfs/comp/lz4/lz4hc.c b/lib/sqfs/comp/lz4/lz4hc.c
new file mode 100644
index 0000000..4bdf96e
--- /dev/null
+++ b/lib/sqfs/comp/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/sqfs/comp/lz4/lz4hc.h b/lib/sqfs/comp/lz4/lz4hc.h
new file mode 100644
index 0000000..157d813
--- /dev/null
+++ b/lib/sqfs/comp/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 */
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