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ZeroTierOne/ext/lz4/lz4.c

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/*
LZ4 - Fast LZ compression algorithm
Copyright (C) 2011-2013, 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 : http://code.google.com/p/lz4/
- LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
*/
//**************************************
// Tuning parameters
//**************************************
// 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 can improve speed, due to cache effect
// Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache
#define MEMORY_USAGE 14
// 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 memory allocation (malloc)).
#define HEAPMODE 0
//**************************************
// CPU Feature Detection
//**************************************
// 32 or 64 bits ?
#if (defined(__x86_64__) || defined(_M_X64) || defined(_WIN64) \
|| defined(__powerpc64__) || defined(__ppc64__) || defined(__PPC64__) \
|| defined(__64BIT__) || defined(_LP64) || defined(__LP64__) \
|| defined(__ia64) || defined(__itanium__) || defined(_M_IA64) ) // Detects 64 bits mode
# define LZ4_ARCH64 1
#else
# define LZ4_ARCH64 0
#endif
// Little Endian or Big Endian ?
// Overwrite the #define below if you know your architecture endianess
#if defined (__GLIBC__)
# include <endian.h>
# if (__BYTE_ORDER == __BIG_ENDIAN)
# define LZ4_BIG_ENDIAN 1
# endif
#elif (defined(__BIG_ENDIAN__) || defined(__BIG_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(__LITTLE_ENDIAN__) || defined(__LITTLE_ENDIAN) || defined(_LITTLE_ENDIAN))
# define LZ4_BIG_ENDIAN 1
#elif defined(__sparc) || defined(__sparc__) \
|| defined(__powerpc__) || defined(__ppc__) || defined(__PPC__) \
|| defined(__hpux) || defined(__hppa) \
|| defined(_MIPSEB) || defined(__s390__)
# define LZ4_BIG_ENDIAN 1
#else
// Little Endian assumed. PDP Endian and other very rare endian format are unsupported.
#endif
// Unaligned memory access is automatically enabled for "common" CPU, such as x86.
// For others CPU, such as ARM, the compiler may be more cautious, inserting unnecessary extra code to ensure aligned access property
// If you know your target CPU supports unaligned memory access, you want to force this option manually to improve performance
#if defined(__ARM_FEATURE_UNALIGNED)
# define LZ4_FORCE_UNALIGNED_ACCESS 1
#endif
// 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 Windows CE does not support Hardware bit count
# define LZ4_FORCE_SW_BITCOUNT
#endif
// BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE :
// This option may provide a small boost to performance for some big endian cpu, although probably modest.
// You may set this option to 1 if data will remain within closed environment.
// This option is useless on Little_Endian CPU (such as x86)
//#define BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE 1
//**************************************
// Compiler Options
//**************************************
#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) // C99
/* "restrict" is a known keyword */
#else
# define restrict // Disable restrict
#endif
#ifdef _MSC_VER // Visual Studio
# define FORCE_INLINE static __forceinline
# include <intrin.h> // For Visual 2005
# if LZ4_ARCH64 // 64-bits
# pragma intrinsic(_BitScanForward64) // For Visual 2005
# pragma intrinsic(_BitScanReverse64) // For Visual 2005
# else // 32-bits
# pragma intrinsic(_BitScanForward) // For Visual 2005
# pragma intrinsic(_BitScanReverse) // For Visual 2005
# endif
# pragma warning(disable : 4127) // disable: C4127: conditional expression is constant
#else
# ifdef __GNUC__
# define FORCE_INLINE static inline __attribute__((always_inline))
# else
# define FORCE_INLINE static inline
# endif
#endif
#ifdef _MSC_VER
# define lz4_bswap16(x) _byteswap_ushort(x)
#else
# define lz4_bswap16(x) ((unsigned short int) ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8)))
#endif
#define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
#if (GCC_VERSION >= 302) || (__INTEL_COMPILER >= 800) || defined(__clang__)
# define expect(expr,value) (__builtin_expect ((expr),(value)) )
#else
# define expect(expr,value) (expr)
#endif
#define likely(expr) expect((expr) != 0, 1)
#define unlikely(expr) expect((expr) != 0, 0)
//**************************************
// Memory routines
//**************************************
#include <stdlib.h> // malloc, calloc, free
#define ALLOCATOR(n,s) calloc(n,s)
#define FREEMEM free
#include <string.h> // memset, memcpy
#define MEM_INIT memset
//**************************************
// Includes
//**************************************
#include "lz4.h"
//**************************************
// Basic Types
//**************************************
#if 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;
#else
typedef unsigned char BYTE;
typedef unsigned short U16;
typedef unsigned int U32;
typedef signed int S32;
typedef unsigned long long U64;
#endif
#if defined(__GNUC__) && !defined(LZ4_FORCE_UNALIGNED_ACCESS)
# define _PACKED __attribute__ ((packed))
#else
# define _PACKED
#endif
#if !defined(LZ4_FORCE_UNALIGNED_ACCESS) && !defined(__GNUC__)
# if defined(__IBMC__) || defined(__SUNPRO_C) || defined(__SUNPRO_CC)
# pragma pack(1)
# else
# pragma pack(push, 1)
# endif
#endif
typedef struct { U16 v; } _PACKED U16_S;
typedef struct { U32 v; } _PACKED U32_S;
typedef struct { U64 v; } _PACKED U64_S;
typedef struct {size_t v;} _PACKED size_t_S;
#if !defined(LZ4_FORCE_UNALIGNED_ACCESS) && !defined(__GNUC__)
# if defined(__SUNPRO_C) || defined(__SUNPRO_CC)
# pragma pack(0)
# else
# pragma pack(pop)
# endif
#endif
#define A16(x) (((U16_S *)(x))->v)
#define A32(x) (((U32_S *)(x))->v)
#define A64(x) (((U64_S *)(x))->v)
#define AARCH(x) (((size_t_S *)(x))->v)
//**************************************
// Constants
//**************************************
#define LZ4_HASHLOG (MEMORY_USAGE-2)
#define HASHTABLESIZE (1 << MEMORY_USAGE)
#define HASHNBCELLS4 (1 << LZ4_HASHLOG)
#define MINMATCH 4
#define COPYLENGTH 8
#define LASTLITERALS 5
#define MFLIMIT (COPYLENGTH+MINMATCH)
const int LZ4_minLength = (MFLIMIT+1);
#define LZ4_64KLIMIT ((1<<16) + (MFLIMIT-1))
#define SKIPSTRENGTH 6 // Increasing this value will make the compression run slower on incompressible data
#define MAXD_LOG 16
#define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
#define ML_BITS 4
#define ML_MASK ((1U<<ML_BITS)-1)
#define RUN_BITS (8-ML_BITS)
#define RUN_MASK ((1U<<RUN_BITS)-1)
#define KB *(1U<<10)
#define MB *(1U<<20)
#define GB *(1U<<30)
//**************************************
// Structures and local types
//**************************************
typedef struct {
U32 hashTable[HASHNBCELLS4];
const BYTE* bufferStart;
const BYTE* base;
const BYTE* nextBlock;
} LZ4_Data_Structure;
typedef enum { notLimited = 0, limited = 1 } limitedOutput_directive;
typedef enum { byPtr, byU32, byU16 } tableType_t;
typedef enum { noPrefix = 0, withPrefix = 1 } prefix64k_directive;
typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
typedef enum { full = 0, partial = 1 } earlyEnd_directive;
//**************************************
// Architecture-specific macros
//**************************************
#define STEPSIZE sizeof(size_t)
#define LZ4_COPYSTEP(d,s) { AARCH(d) = AARCH(s); d+=STEPSIZE; s+=STEPSIZE; }
#define LZ4_COPY8(d,s) { LZ4_COPYSTEP(d,s); if (STEPSIZE<8) LZ4_COPYSTEP(d,s); }
#define LZ4_SECURECOPY(d,s,e) { if ((STEPSIZE==4)||(d<e)) LZ4_WILDCOPY(d,s,e); }
#if LZ4_ARCH64 // 64-bit
# define HTYPE U32
# define INITBASE(base) const BYTE* const base = ip
#else // 32-bit
# define HTYPE const BYTE*
# define INITBASE(base) const int base = 0
#endif
#if (defined(LZ4_BIG_ENDIAN) && !defined(BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE))
# define LZ4_READ_LITTLEENDIAN_16(d,s,p) { U16 v = A16(p); v = lz4_bswap16(v); d = (s) - v; }
# define LZ4_WRITE_LITTLEENDIAN_16(p,i) { U16 v = (U16)(i); v = lz4_bswap16(v); A16(p) = v; p+=2; }
#else // Little Endian
# define LZ4_READ_LITTLEENDIAN_16(d,s,p) { d = (s) - A16(p); }
# define LZ4_WRITE_LITTLEENDIAN_16(p,v) { A16(p) = v; p+=2; }
#endif
//**************************************
// Macros
//**************************************
#define LZ4_WILDCOPY(d,s,e) { do { LZ4_COPY8(d,s) } while (d<e); } // at the end, d>=e;
//****************************
// Private functions
//****************************
#if LZ4_ARCH64
FORCE_INLINE int LZ4_NbCommonBytes (register U64 val)
{
# if defined(LZ4_BIG_ENDIAN)
# if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
unsigned long r = 0;
_BitScanReverse64( &r, val );
return (int)(r>>3);
# elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
return (__builtin_clzll(val) >> 3);
# else
int r;
if (!(val>>32)) { r=4; } else { r=0; val>>=32; }
if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
r += (!val);
return r;
# endif
# else
# if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
unsigned long r = 0;
_BitScanForward64( &r, val );
return (int)(r>>3);
# elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
return (__builtin_ctzll(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
# endif
}
#else
FORCE_INLINE int LZ4_NbCommonBytes (register U32 val)
{
# if defined(LZ4_BIG_ENDIAN)
# if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
unsigned long r = 0;
_BitScanReverse( &r, val );
return (int)(r>>3);
# elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
return (__builtin_clz(val) >> 3);
# else
int r;
if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
r += (!val);
return r;
# endif
# else
# if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)
unsigned long r;
_BitScanForward( &r, val );
return (int)(r>>3);
# elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)
return (__builtin_ctz(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
# endif
}
#endif
//****************************
// Compression functions
//****************************
FORCE_INLINE int LZ4_hashSequence(U32 sequence, tableType_t tableType)
{
if (tableType == byU16)
return (((sequence) * 2654435761U) >> ((MINMATCH*8)-(LZ4_HASHLOG+1)));
else
return (((sequence) * 2654435761U) >> ((MINMATCH*8)-LZ4_HASHLOG));
}
FORCE_INLINE int LZ4_hashPosition(const BYTE* p, tableType_t tableType) { return LZ4_hashSequence(A32(p), tableType); }
FORCE_INLINE void LZ4_putPositionOnHash(const BYTE* p, U32 h, void* tableBase, tableType_t tableType, const BYTE* srcBase)
{
switch (tableType)
{
case byPtr: { const BYTE** hashTable = (const BYTE**) tableBase; hashTable[h] = p; break; }
case byU32: { U32* hashTable = (U32*) tableBase; hashTable[h] = (U32)(p-srcBase); break; }
case byU16: { U16* hashTable = (U16*) tableBase; hashTable[h] = (U16)(p-srcBase); break; }
}
}
FORCE_INLINE void LZ4_putPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
{
U32 h = LZ4_hashPosition(p, tableType);
LZ4_putPositionOnHash(p, h, tableBase, tableType, srcBase);
}
FORCE_INLINE const BYTE* LZ4_getPositionOnHash(U32 h, void* tableBase, tableType_t tableType, const BYTE* srcBase)
{
if (tableType == byPtr) { const BYTE** hashTable = (const BYTE**) tableBase; return hashTable[h]; }
if (tableType == byU32) { U32* hashTable = (U32*) tableBase; return hashTable[h] + srcBase; }
{ U16* hashTable = (U16*) tableBase; return hashTable[h] + srcBase; } // default, to ensure a return
}
FORCE_INLINE const BYTE* LZ4_getPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
{
U32 h = LZ4_hashPosition(p, tableType);
return LZ4_getPositionOnHash(h, tableBase, tableType, srcBase);
}
FORCE_INLINE int LZ4_compress_generic(
void* ctx,
const char* source,
char* dest,
int inputSize,
int maxOutputSize,
limitedOutput_directive limitedOutput,
tableType_t tableType,
prefix64k_directive prefix)
{
const BYTE* ip = (const BYTE*) source;
const BYTE* const base = (prefix==withPrefix) ? ((LZ4_Data_Structure*)ctx)->base : (const BYTE*) source;
const BYTE* const lowLimit = ((prefix==withPrefix) ? ((LZ4_Data_Structure*)ctx)->bufferStart : (const BYTE*)source);
const BYTE* anchor = (const BYTE*) source;
const BYTE* const iend = ip + inputSize;
const BYTE* const mflimit = iend - MFLIMIT;
const BYTE* const matchlimit = iend - LASTLITERALS;
BYTE* op = (BYTE*) dest;
BYTE* const oend = op + maxOutputSize;
int length;
const int skipStrength = SKIPSTRENGTH;
U32 forwardH;
// Init conditions
if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) return 0; // Unsupported input size, too large (or negative)
if ((prefix==withPrefix) && (ip != ((LZ4_Data_Structure*)ctx)->nextBlock)) return 0; // must continue from end of previous block
if (prefix==withPrefix) ((LZ4_Data_Structure*)ctx)->nextBlock=iend; // do it now, due to potential early exit
if ((tableType == byU16) && (inputSize>=LZ4_64KLIMIT)) return 0; // Size too large (not within 64K limit)
if (inputSize<LZ4_minLength) goto _last_literals; // Input too small, no compression (all literals)
// First Byte
LZ4_putPosition(ip, ctx, tableType, base);
ip++; forwardH = LZ4_hashPosition(ip, tableType);
// Main Loop
for ( ; ; )
{
int findMatchAttempts = (1U << skipStrength) + 3;
const BYTE* forwardIp = ip;
const BYTE* ref;
BYTE* token;
// Find a match
do {
U32 h = forwardH;
int step = findMatchAttempts++ >> skipStrength;
ip = forwardIp;
forwardIp = ip + step;
if unlikely(forwardIp > mflimit) { goto _last_literals; }
forwardH = LZ4_hashPosition(forwardIp, tableType);
ref = LZ4_getPositionOnHash(h, ctx, tableType, base);
LZ4_putPositionOnHash(ip, h, ctx, tableType, base);
} while ((ref + MAX_DISTANCE < ip) || (A32(ref) != A32(ip)));
// Catch up
while ((ip>anchor) && (ref > lowLimit) && unlikely(ip[-1]==ref[-1])) { ip--; ref--; }
// Encode Literal length
length = (int)(ip - anchor);
token = op++;
if ((limitedOutput) && unlikely(op + length + (2 + 1 + LASTLITERALS) + (length>>8) > oend)) return 0; // Check output limit
if (length>=(int)RUN_MASK)
{
int 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
{ BYTE* end=(op)+(length); LZ4_WILDCOPY(op,anchor,end); op=end; }
_next_match:
// Encode Offset
LZ4_WRITE_LITTLEENDIAN_16(op,(U16)(ip-ref));
// Start Counting
ip+=MINMATCH; ref+=MINMATCH; // MinMatch already verified
anchor = ip;
while likely(ip<matchlimit-(STEPSIZE-1))
{
size_t diff = AARCH(ref) ^ AARCH(ip);
if (!diff) { ip+=STEPSIZE; ref+=STEPSIZE; continue; }
ip += LZ4_NbCommonBytes(diff);
goto _endCount;
}
if (LZ4_ARCH64) if ((ip<(matchlimit-3)) && (A32(ref) == A32(ip))) { ip+=4; ref+=4; }
if ((ip<(matchlimit-1)) && (A16(ref) == A16(ip))) { ip+=2; ref+=2; }
if ((ip<matchlimit) && (*ref == *ip)) ip++;
_endCount:
// Encode MatchLength
length = (int)(ip - anchor);
if ((limitedOutput) && unlikely(op + (1 + LASTLITERALS) + (length>>8) > oend)) return 0; // Check output limit
if (length>=(int)ML_MASK)
{
*token += ML_MASK;
length -= ML_MASK;
for (; length > 509 ; length-=510) { *op++ = 255; *op++ = 255; }
if (length >= 255) { length-=255; *op++ = 255; }
*op++ = (BYTE)length;
}
else *token += (BYTE)(length);
// Test end of chunk
if (ip > mflimit) { anchor = ip; break; }
// Fill table
LZ4_putPosition(ip-2, ctx, tableType, base);
// Test next position
ref = LZ4_getPosition(ip, ctx, tableType, base);
LZ4_putPosition(ip, ctx, tableType, base);
if ((ref + MAX_DISTANCE >= ip) && (A32(ref) == A32(ip))) { token = op++; *token=0; goto _next_match; }
// Prepare next loop
anchor = ip++;
forwardH = LZ4_hashPosition(ip, tableType);
}
_last_literals:
// Encode Last Literals
{
int lastRun = (int)(iend - anchor);
if ((limitedOutput) && (((char*)op - dest) + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > (U32)maxOutputSize)) return 0; // Check output limit
if (lastRun>=(int)RUN_MASK) { *op++=(RUN_MASK<<ML_BITS); lastRun-=RUN_MASK; for(; lastRun >= 255 ; lastRun-=255) *op++ = 255; *op++ = (BYTE) lastRun; }
else *op++ = (BYTE)(lastRun<<ML_BITS);
memcpy(op, anchor, iend - anchor);
op += iend-anchor;
}
// End
return (int) (((char*)op)-dest);
}
int LZ4_compress(const char* source, char* dest, int inputSize)
{
#if (HEAPMODE)
void* ctx = ALLOCATOR(HASHNBCELLS4, 4); // Aligned on 4-bytes boundaries
#else
U32 ctx[1U<<(MEMORY_USAGE-2)] = {0}; // Ensure data is aligned on 4-bytes boundaries
#endif
int result;
if (inputSize < (int)LZ4_64KLIMIT)
result = LZ4_compress_generic((void*)ctx, source, dest, inputSize, 0, notLimited, byU16, noPrefix);
else
result = LZ4_compress_generic((void*)ctx, source, dest, inputSize, 0, notLimited, (sizeof(void*)==8) ? byU32 : byPtr, noPrefix);
#if (HEAPMODE)
FREEMEM(ctx);
#endif
return result;
}
int LZ4_compress_continue (void* LZ4_Data, const char* source, char* dest, int inputSize)
{
return LZ4_compress_generic(LZ4_Data, source, dest, inputSize, 0, notLimited, byU32, withPrefix);
}
int LZ4_compress_limitedOutput(const char* source, char* dest, int inputSize, int maxOutputSize)
{
#if (HEAPMODE)
void* ctx = ALLOCATOR(HASHNBCELLS4, 4); // Aligned on 4-bytes boundaries
#else
U32 ctx[1U<<(MEMORY_USAGE-2)] = {0}; // Ensure data is aligned on 4-bytes boundaries
#endif
int result;
if (inputSize < (int)LZ4_64KLIMIT)
result = LZ4_compress_generic((void*)ctx, source, dest, inputSize, maxOutputSize, limited, byU16, noPrefix);
else
result = LZ4_compress_generic((void*)ctx, source, dest, inputSize, maxOutputSize, limited, (sizeof(void*)==8) ? byU32 : byPtr, noPrefix);
#if (HEAPMODE)
FREEMEM(ctx);
#endif
return result;
}
int LZ4_compress_limitedOutput_continue (void* LZ4_Data, const char* source, char* dest, int inputSize, int maxOutputSize)
{
return LZ4_compress_generic(LZ4_Data, source, dest, inputSize, maxOutputSize, limited, byU32, withPrefix);
}
//****************************
// Stream functions
//****************************
FORCE_INLINE void LZ4_init(LZ4_Data_Structure* lz4ds, const BYTE* base)
{
MEM_INIT(lz4ds->hashTable, 0, sizeof(lz4ds->hashTable));
lz4ds->bufferStart = base;
lz4ds->base = base;
lz4ds->nextBlock = base;
}
void* LZ4_create (const char* inputBuffer)
{
void* lz4ds = ALLOCATOR(1, sizeof(LZ4_Data_Structure));
LZ4_init ((LZ4_Data_Structure*)lz4ds, (const BYTE*)inputBuffer);
return lz4ds;
}
int LZ4_free (void* LZ4_Data)
{
FREEMEM(LZ4_Data);
return (0);
}
char* LZ4_slideInputBuffer (void* LZ4_Data)
{
LZ4_Data_Structure* lz4ds = (LZ4_Data_Structure*)LZ4_Data;
size_t delta = lz4ds->nextBlock - (lz4ds->bufferStart + 64 KB);
if ( (lz4ds->base - delta > lz4ds->base) // underflow control
|| ((size_t)(lz4ds->nextBlock - lz4ds->base) > 0xE0000000) ) // close to 32-bits limit
{
size_t deltaLimit = (lz4ds->nextBlock - 64 KB) - lz4ds->base;
int nH;
for (nH=0; nH < HASHNBCELLS4; nH++)
{
if ((size_t)(lz4ds->hashTable[nH]) < deltaLimit) lz4ds->hashTable[nH] = 0;
else lz4ds->hashTable[nH] -= (U32)deltaLimit;
}
memcpy((void*)(lz4ds->bufferStart), (const void*)(lz4ds->nextBlock - 64 KB), 64 KB);
lz4ds->base = lz4ds->bufferStart;
lz4ds->nextBlock = lz4ds->base + 64 KB;
}
else
{
memcpy((void*)(lz4ds->bufferStart), (const void*)(lz4ds->nextBlock - 64 KB), 64 KB);
lz4ds->nextBlock -= delta;
lz4ds->base -= delta;
}
return (char*)(lz4ds->nextBlock);
}
//****************************
// Decompression functions
//****************************
// This generic decompression function cover all use cases.
// It shall be instanciated several times, using different sets of directives
// Note that it is essential this generic function is really inlined,
// in order to remove useless branches during compilation optimisation.
FORCE_INLINE int LZ4_decompress_generic(
const char* source,
char* dest,
int inputSize, //
int outputSize, // If endOnInput==endOnInputSize, this value is the max size of Output Buffer.
int endOnInput, // endOnOutputSize, endOnInputSize
int prefix64k, // noPrefix, withPrefix
int partialDecoding, // full, partial
int targetOutputSize // only used if partialDecoding==partial
)
{
// Local Variables
const BYTE* restrict ip = (const BYTE*) source;
const BYTE* ref;
const BYTE* const iend = ip + inputSize;
BYTE* op = (BYTE*) dest;
BYTE* const oend = op + outputSize;
BYTE* cpy;
BYTE* oexit = op + targetOutputSize;
const size_t dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0}; // static reduces speed for LZ4_decompress_safe() on GCC64
static const size_t dec64table[] = {0, 0, 0, (size_t)-1, 0, 1, 2, 3};
// Special cases
if ((partialDecoding) && (oexit> oend-MFLIMIT)) oexit = oend-MFLIMIT; // targetOutputSize too high => decode everything
if ((endOnInput) && unlikely(outputSize==0)) return ((inputSize==1) && (*ip==0)) ? 0 : -1; // Empty output buffer
if ((!endOnInput) && unlikely(outputSize==0)) return (*ip==0?1:-1);
// Main Loop
while (1)
{
unsigned token;
size_t length;
// get runlength
token = *ip++;
if ((length=(token>>ML_BITS)) == RUN_MASK)
{
unsigned s=255;
while (((endOnInput)?ip<iend:1) && (s==255))
{
s = *ip++;
length += s;
}
}
// copy literals
cpy = op+length;
if (((endOnInput) && ((cpy>(partialDecoding?oexit:oend-MFLIMIT)) || (ip+length>iend-(2+1+LASTLITERALS))) )
|| ((!endOnInput) && (cpy>oend-COPYLENGTH)))
{
if (partialDecoding)
{
if (cpy > oend) goto _output_error; // Error : write attempt beyond end of output buffer
if ((endOnInput) && (ip+length > iend)) goto _output_error; // Error : read attempt beyond end of input buffer
}
else
{
if ((!endOnInput) && (cpy != oend)) goto _output_error; // Error : block decoding must stop exactly there
if ((endOnInput) && ((ip+length != iend) || (cpy > oend))) goto _output_error; // Error : input must be consumed
}
memcpy(op, ip, length);
ip += length;
op += length;
break; // Necessarily EOF, due to parsing restrictions
}
LZ4_WILDCOPY(op, ip, cpy); ip -= (op-cpy); op = cpy;
// get offset
LZ4_READ_LITTLEENDIAN_16(ref,cpy,ip); ip+=2;
if ((prefix64k==noPrefix) && unlikely(ref < (BYTE* const)dest)) goto _output_error; // Error : offset outside destination buffer
// get matchlength
if ((length=(token&ML_MASK)) == ML_MASK)
{
while ((!endOnInput) || (ip<iend-(LASTLITERALS+1))) // Ensure enough bytes remain for LASTLITERALS + token
{
unsigned s = *ip++;
length += s;
if (s==255) continue;
break;
}
}
// copy repeated sequence
if unlikely((op-ref)<(int)STEPSIZE)
{
const size_t dec64 = dec64table[(sizeof(void*)==4) ? 0 : op-ref];
op[0] = ref[0];
op[1] = ref[1];
op[2] = ref[2];
op[3] = ref[3];
op += 4, ref += 4; ref -= dec32table[op-ref];
A32(op) = A32(ref);
op += STEPSIZE-4; ref -= dec64;
} else { LZ4_COPYSTEP(op,ref); }
cpy = op + length - (STEPSIZE-4);
if unlikely(cpy>oend-COPYLENGTH-(STEPSIZE-4))
{
if (cpy > oend-LASTLITERALS) goto _output_error; // Error : last 5 bytes must be literals
LZ4_SECURECOPY(op, ref, (oend-COPYLENGTH));
while(op<cpy) *op++=*ref++;
op=cpy;
continue;
}
LZ4_WILDCOPY(op, ref, cpy);
op=cpy; // correction
}
// end of decoding
if (endOnInput)
return (int) (((char*)op)-dest); // Nb of output bytes decoded
else
return (int) (((char*)ip)-source); // Nb of input bytes read
// Overflow error detected
_output_error:
return (int) (-(((char*)ip)-source))-1;
}
int LZ4_decompress_safe(const char* source, char* dest, int inputSize, int maxOutputSize)
{
return LZ4_decompress_generic(source, dest, inputSize, maxOutputSize, endOnInputSize, noPrefix, full, 0);
}
int LZ4_decompress_safe_withPrefix64k(const char* source, char* dest, int inputSize, int maxOutputSize)
{
return LZ4_decompress_generic(source, dest, inputSize, maxOutputSize, endOnInputSize, withPrefix, full, 0);
}
int LZ4_decompress_safe_partial(const char* source, char* dest, int inputSize, int targetOutputSize, int maxOutputSize)
{
return LZ4_decompress_generic(source, dest, inputSize, maxOutputSize, endOnInputSize, noPrefix, partial, targetOutputSize);
}
int LZ4_decompress_fast_withPrefix64k(const char* source, char* dest, int outputSize)
{
return LZ4_decompress_generic(source, dest, 0, outputSize, endOnOutputSize, withPrefix, full, 0);
}
int LZ4_decompress_fast(const char* source, char* dest, int outputSize)
{
#ifdef _MSC_VER // This version is faster with Visual
return LZ4_decompress_generic(source, dest, 0, outputSize, endOnOutputSize, noPrefix, full, 0);
#else
return LZ4_decompress_generic(source, dest, 0, outputSize, endOnOutputSize, withPrefix, full, 0);
#endif
}
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