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 homepage : http://fastcompression.blogspot.com/p/lz4.html
   - LZ4 source repository : http://code.google.com/p/lz4/
*/

#ifndef LZ4_CS_ADAPTER
//**************************************
// 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

// BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE :
// This will provide a small boost to performance for big endian cpu, but the resulting compressed stream will be incompatible with little-endian CPU.
// You can set this option to 1 in situations where data will remain within closed environment
// This option is useless on Little_Endian CPU (such as x86)
//#define BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE 1

//**************************************
// CPU Feature Detection
//**************************************
// 32 or 64 bits ?
#ifndef LZ4_ARCH64

#if (defined(__x86_64__) || defined(__x86_64) || defined(__amd64__) || defined(__amd64) || defined(__ppc64__) || defined(_WIN64) || defined(__LP64__) || defined(_LP64) )   // Detects 64 bits mode
#  define LZ4_ARCH64 1
#else
#  define LZ4_ARCH64 0
#endif

#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(__ppc__) || defined(_POWER) || defined(__powerpc__) || defined(_ARCH_PPC) || defined(__PPC__) || defined(__PPC) || defined(PPC) || defined(__powerpc__) || defined(__powerpc) || defined(powerpc) \
   || 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, the compiler will be more cautious, and insert extra code to ensure aligned access is respected
// 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

//**************************************
// Compiler Options
//**************************************
#if __STDC_VERSION__ >= 199901L   // C99
/* "restrict" is a known keyword */
#else
#  define restrict // Disable restrict
#endif

#define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)

#if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT) // Visual Studio
#  include <intrin.h>   // For Visual 2005
#  if LZ4_ARCH64 && defined(_M_X64) // 64-bit
#    pragma intrinsic(_BitScanForward64) // For Visual 2005
#    pragma intrinsic(_BitScanReverse64) // For Visual 2005
#  else
#    pragma intrinsic(_BitScanForward) // For Visual 2005
#    pragma intrinsic(_BitScanReverse) // For Visual 2005
#  endif
#  pragma warning(disable : 4127)        // disable: C4127: conditional expression is constant
#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

#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)


//**************************************
// Includes
//**************************************
#include <stdlib.h>   // for malloc
#include <string.h>   // for memset
#include "lz4.h"


//**************************************
// Basic Types
//**************************************
#if defined(_MSC_VER)    // Visual Studio does not support 'stdint' natively
#  define BYTE      unsigned __int8
#  define U16       unsigned __int16
#  define U32       unsigned __int32
#  define S32       __int32
#  define U64       unsigned __int64
#  define S64       __int64
#else
#  include <stdint.h>
#  define BYTE      uint8_t
#  define U16       uint16_t
#  define U32       uint32_t
#  define S32       int32_t
#  define U64       uint64_t
#  define S64       int64_t
#endif

#ifndef LZ4_FORCE_UNALIGNED_ACCESS
#  pragma pack(push, 1)
#endif

typedef struct _U16_S { U16 v; } U16_S;
typedef struct _U32_S { U32 v; } U32_S;
typedef struct _U64_S { U64 v; } U64_S;

#ifndef LZ4_FORCE_UNALIGNED_ACCESS
#  pragma pack(pop)
#endif

#define A64(x) (((U64_S *)(x))->v)
#define A32(x) (((U32_S *)(x))->v)
#define A16(x) (((U16_S *)(x))->v)


//**************************************
// Constants
//**************************************
#define MINMATCH 4

#define HASH_LOG (MEMORY_USAGE-2)
#define HASHTABLESIZE (1 << HASH_LOG)
#define HASH_MASK (HASHTABLESIZE - 1)

#define NOTCOMPRESSIBLE_DETECTIONLEVEL 6 // Increasing this value will make the algorithm slower on incompressible data
#define SKIPSTRENGTH (NOTCOMPRESSIBLE_DETECTIONLEVEL>2?NOTCOMPRESSIBLE_DETECTIONLEVEL:2)
#define STACKLIMIT 13
#define HEAPMODE (HASH_LOG>STACKLIMIT)  // Defines if memory is allocated into the stack (local variable), or into the heap (malloc()).
#define COPYLENGTH 8
#define LASTLITERALS 5
#define MFLIMIT (COPYLENGTH+MINMATCH)
#define MINLENGTH (MFLIMIT+1)

#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)


//**************************************
// Architecture-specific macros
//**************************************
#if LZ4_ARCH64  // 64-bit
#  define STEPSIZE 8
#  define UARCH U64
#  define AARCH A64
#  define LZ4_COPYSTEP(s,d)       A64(d) = A64(s); d+=8; s+=8;
#  define LZ4_COPYPACKET(s,d)     LZ4_COPYSTEP(s,d)
#  define LZ4_SECURECOPY(s,d,e)   if (d<e) LZ4_WILDCOPY(s,d,e)
#  define HTYPE                   U32
#  define INITBASE(base)          const BYTE* const base = ip
#else       // 32-bit
#  define STEPSIZE 4
#  define UARCH U32
#  define AARCH A32
#  define LZ4_COPYSTEP(s,d)       A32(d) = A32(s); d+=4; s+=4;
#  define LZ4_COPYPACKET(s,d)     LZ4_COPYSTEP(s,d); LZ4_COPYSTEP(s,d);
#  define LZ4_SECURECOPY          LZ4_WILDCOPY
#  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

//**************************************
// Local structures
//**************************************
struct refTables
{
    HTYPE hashTable[HASHTABLESIZE];
};

//**************************************
// Macros
//**************************************
#define LZ4_HASH_FUNCTION(i)    (((i) * 2654435761U) >> ((MINMATCH*8)-HASH_LOG))
#define LZ4_HASH_VALUE(p)       LZ4_HASH_FUNCTION(A32(p))
#define LZ4_WILDCOPY(s,d,e)     do { LZ4_COPYPACKET(s,d) } while (d<e);
#define LZ4_BLINDCOPY(s,d,l)    { BYTE* e=(d)+l; LZ4_WILDCOPY(s,d,e); d=e; }

#endif // LZ4_CS_ADAPTER

//****************************
// Private functions
//****************************
#ifndef LZ4_CS_ADAPTER

#if LZ4_ARCH64

static inline int LZ4_NbCommonBytes (register U64 val)
{
#if defined(LZ4_BIG_ENDIAN)
    #if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT) && defined(_M_X64)
    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) && defined(_M_X64)
    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 };
#ifdef LZ4_MK_OPT
    return DeBruijnBytePos[((U64)((U64)((S64)val & -(S64)val) * 0x0218A392CDABBD3F)) >> 58];
#else
    return DeBruijnBytePos[((U64)((val & -val) * 0x0218A392CDABBD3F)) >> 58];
#endif
    #endif
#endif
}

#else

static 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 };
#ifdef LZ4_MK_OPT
    return DeBruijnBytePos[((U32)((U32)((S32)val & -(S32)val) * 0x077CB531U)) >> 27];
#else
    return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27];
#endif
    #endif
#endif
}

#endif

#endif // LZ4_CS_ADAPTER

//******************************
// Compression functions
//******************************

// LZ4_compressCtx :
// -----------------
// Compress 'isize' bytes from 'source' into an output buffer 'dest' of maximum size 'maxOutputSize'.
// If it cannot achieve it, compression will stop, and result of the function will be zero.
// return : the number of bytes written in buffer 'dest', or 0 if the compression fails

static inline int LZ4_compressCtx(void** ctx,
    const char* source,
    char* dest,
    int inputSize,
    int maxOutputSize)
{
#if HEAPMODE
    struct refTables *srt = (struct refTables *) (*ctx);
    HTYPE* HashTable;
#else
    HTYPE HashTable[HASHTABLESIZE] = {0};
#endif

    const BYTE* ip = (BYTE*) source;
    INITBASE(base);
    const BYTE* anchor = ip;
    const BYTE* const iend = ip + inputSize;
    const BYTE* const mflimit = iend - MFLIMIT;

    BYTE* op = (BYTE*) dest;
    BYTE* const oend = op + maxOutputSize;

#ifdef LZ4_MK_OPT
    const BYTE* matchlimit = iend - LASTLITERALS;
    const BYTE* matchlimit_1 = matchlimit - 1;
    #if (LZ4_ARCH64 == 1)
    const BYTE* matchlimit_3 = matchlimit - 3;
    #endif
    const BYTE* matchlimit_STEPSIZE_1 = matchlimit - (STEPSIZE - 1);
    const BYTE* oend_LASTLITERALS_1 = oend - (1 + LASTLITERALS);
    const BYTE* oend_LASTLITERALS_3 = oend - (2 + 1 + LASTLITERALS);
#else
    #define matchlimit (iend - LASTLITERALS)
#endif

    int length;
#ifndef LZ4_CS_ADAPTER
    const int skipStrength = SKIPSTRENGTH;
#endif
    U32 forwardH;

    // Init
    if (inputSize<MINLENGTH) goto _last_literals;
#ifndef LZ4_CS_ADAPTER
#if HEAPMODE
    if (*ctx == NULL)
    {
        srt = (struct refTables *) malloc ( sizeof(struct refTables) );
        *ctx = (void*) srt;
    }
    HashTable = (HTYPE*)(srt->hashTable);
    memset((void*)HashTable, 0, sizeof(srt->hashTable));
#else
    (void) ctx;
#endif
#endif

    // First Byte
    HashTable[LZ4_HASH_VALUE(ip)] = (HTYPE)(ip - base);
    ip++; forwardH = LZ4_HASH_VALUE(ip);

    // Main Loop
    while (1)
    {
        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_HASH_VALUE(forwardIp);
            ref = base + HashTable[h];
            HashTable[h] = (HTYPE)(ip - base);

        } while ((ref < ip - MAX_DISTANCE) || (A32(ref) != A32(ip)));

        // Catch up
        while ((ip>anchor) && (ref>(BYTE*)source) && unlikely(ip[-1]==ref[-1])) { ip--; ref--; }

        // Encode Literal length
        length = (int)(ip - anchor);
        token = op++;
#ifdef LZ4_MK_OPT
        if unlikely(op + length + (length>>8) > oend_LASTLITERALS_3) return 0; // Check output limit
#else
        if unlikely(op + length + (2 + 1 + LASTLITERALS) + (length>>8) > oend) return 0; // Check output limit
#endif
#ifdef _MSC_VER
        if (length>=(int)RUN_MASK)
        {
            int len = length-RUN_MASK;
            *token=(RUN_MASK<<ML_BITS);
            if (len>254)
            {
                do { *op++ = 255; len -= 255; } while (len>254);
                *op++ = (BYTE)len;
                memcpy(op, anchor, length);
                op += length;
                goto _next_match;
            }
            else
            *op++ = (BYTE)len;
        }
        else *token = (BYTE)(length<<ML_BITS);
#else
        if (length>=(int)RUN_MASK)
        {
            int len;
            *token=(RUN_MASK<<ML_BITS);
            len = length-RUN_MASK;
            for(; len > 254 ; len-=255) *op++ = 255;
            *op++ = (BYTE)len;
        }
        else *token = (length<<ML_BITS);
#endif

        // Copy Literals
        LZ4_BLINDCOPY(anchor, op, length);

_next_match:
        // Encode Offset
        LZ4_WRITE_LITTLEENDIAN_16(op,(U16)(ip-ref));

        // Start Counting
        ip+=MINMATCH; ref+=MINMATCH;    // MinMatch already verified
        anchor = ip;
#ifdef LZ4_MK_OPT
        while likely(ip < matchlimit_STEPSIZE_1)
#else
        while likely(ip<matchlimit-(STEPSIZE-1))
#endif
        {
            UARCH diff = AARCH(ref) ^ AARCH(ip);
            if (!diff) { ip += STEPSIZE; ref += STEPSIZE; continue; }
            ip += LZ4_NbCommonBytes(diff);
            goto _endCount;
        }
#ifdef LZ4_MK_OPT
        #if (LZ4_ARCH64 == 1)
        if ((ip<matchlimit_3) && (A32(ref) == A32(ip))) { ip+=4; ref+=4; }
        #endif
        if ((ip<matchlimit_1) && (A16(ref) == A16(ip))) { ip+=2; ref+=2; }
        if ((ip<matchlimit) && (*ref == *ip)) ip++;
#else
        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++;
#endif

_endCount:

        // Encode MatchLength
        length = (int)(ip - anchor);
#ifdef LZ4_MK_OPT
        if unlikely(op + (length>>8) > oend_LASTLITERALS_1) return 0; // Check output limit
#else
        if unlikely(op + (1 + LASTLITERALS) + (length>>8) > oend) return 0;         // Check output limit
#endif

        if (length>=(int)ML_MASK)
        {
            *token+=ML_MASK;
            length -= ML_MASK;
            for (; length > 509 ; length-=510) { *op++ = 255; *op++ = 255; }
            if (length > 254) { length-=255; *op++ = 255; }
            *op++ = (BYTE)length;
        }
        else *token += (BYTE)length;

        // Test end of chunk
        if (ip > mflimit) { anchor = ip;  break; }

        // Fill table
        HashTable[LZ4_HASH_VALUE(ip-2)] = (HTYPE)(ip - 2 - base);

        // Test next position
#ifdef LZ4_MK_OPT
        U32 h = LZ4_HASH_VALUE(ip);
        ref = base + HashTable[h];
        HashTable[h] = (HTYPE)(ip - base);
#else
        ref = base + HashTable[LZ4_HASH_VALUE(ip)];
        HashTable[LZ4_HASH_VALUE(ip)] = (HTYPE)(ip - base);
#endif

        if ((ref > ip - (MAX_DISTANCE + 1)) && (A32(ref) == A32(ip))) { token = op++; *token=0; goto _next_match; }

        // Prepare next loop
        anchor = ip++;
        forwardH = LZ4_HASH_VALUE(ip);
    }

_last_literals:
    // Encode Last Literals
    {
        int lastRun = (int)(iend - anchor);
#ifdef LZ4_MK_OPT
        if ((BYTE*)op + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > oend) return 0;
#else
        if (((char*)op - dest) + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > (U32)maxOutputSize) return 0;  // Check output limit
#endif
        if (lastRun>=(int)RUN_MASK) { *op++=(RUN_MASK<<ML_BITS); lastRun-=RUN_MASK; for(; lastRun > 254 ; 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);
}

// Note : this function is valid only if isize < LZ4_64KLIMIT
#ifndef LZ4_CS_ADAPTER
#define LZ4_64KLIMIT ((1<<16) + (MFLIMIT-1))
#define HASHLOG64K (HASH_LOG+1)
#define HASH64KTABLESIZE (1U<<HASHLOG64K)
#define LZ4_HASH64K_FUNCTION(i) (((i) * 2654435761U) >> ((MINMATCH*8)-HASHLOG64K))
#define LZ4_HASH64K_VALUE(p)    LZ4_HASH64K_FUNCTION(A32(p))
#endif

static inline int LZ4_compress64kCtx(void** ctx,
                 const char* source,
                 char* dest,
                 int isize,
                 int maxOutputSize)
{
#if HEAPMODE
    struct refTables *srt = (struct refTables *) (*ctx);
    U16* HashTable;
#else
    U16 HashTable[HASH64KTABLESIZE] = {0};
#endif

    const BYTE* ip = (BYTE*) source;
    const BYTE* anchor = ip;
    const BYTE* const base = ip;
    const BYTE* const iend = ip + isize;
    const BYTE* const mflimit = iend - MFLIMIT;

    BYTE* op = (BYTE*) dest;
    BYTE* const oend = op + maxOutputSize;

#ifdef LZ4_MK_OPT
    const BYTE* matchlimit = iend - LASTLITERALS;
    const BYTE* matchlimit_1 = matchlimit - 1;
    #if (LZ4_ARCH64 == 1)
    const BYTE* matchlimit_3 = matchlimit - 3;
    #endif
    const BYTE* matchlimit_STEPSIZE_1 = matchlimit - (STEPSIZE - 1);
    const BYTE* oend_LASTLITERALS_1 = oend - (1 + LASTLITERALS);
    const BYTE* oend_LASTLITERALS_3 = oend - (2 + 1 + LASTLITERALS);
#else
    #define matchlimit (iend - LASTLITERALS)
#endif

    int len, length;
#ifndef LZ4_CS_ADAPTER
    const int skipStrength = SKIPSTRENGTH;
#endif
    U32 forwardH;

    // Init
    if (isize < MINLENGTH) goto _last_literals;
#ifndef LZ4_CS_ADAPTER
#if HEAPMODE
    if (*ctx == NULL)
    {
        srt = (struct refTables *) malloc ( sizeof(struct refTables) );
        *ctx = (void*) srt;
    }
    HashTable = (U16*)(srt->hashTable);
    memset((void*)HashTable, 0, sizeof(srt->hashTable));
#else
    (void) ctx;
#endif
#endif

    // First Byte
    ip++; forwardH = LZ4_HASH64K_VALUE(ip);

    // Main Loop
    while (1)
    {
        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 (forwardIp > mflimit) goto _last_literals;

            forwardH = LZ4_HASH64K_VALUE(forwardIp);
            ref = base + HashTable[h];
            HashTable[h] = (U16)(ip - base);

        } while (A32(ref) != A32(ip));

        // Catch up
        while ((ip>anchor) && (ref>(BYTE*)source) && (ip[-1]==ref[-1])) { ip--; ref--; }

        // Encode Literal length
        length = (int)(ip - anchor);
        token = op++;
#ifdef LZ4_MK_OPT
        if unlikely(op + length + (length>>8) > oend_LASTLITERALS_3) return 0; // Check output limit
#else
        if unlikely(op + length + (2 + 1 + LASTLITERALS) + (length>>8) > oend) return 0;        // Check output limit
#endif

#ifdef _MSC_VER
        if (length>=(int)RUN_MASK)
        {
            int len = length-RUN_MASK;
            *token=(RUN_MASK<<ML_BITS);
            if (len>254)
            {
                do { *op++ = 255; len -= 255; } while (len>254);
                *op++ = (BYTE)len;
                memcpy(op, anchor, length);
                op += length;
                goto _next_match;
            }
            else
            *op++ = (BYTE)len;
        }
        else *token = (BYTE)(length<<ML_BITS);
#else
        if (length>=(int)RUN_MASK) { *token=(RUN_MASK<<ML_BITS); len = length-RUN_MASK; for(; len > 254 ; len-=255) *op++ = 255; *op++ = (BYTE)len; }
        else *token = (length<<ML_BITS);
#endif

        // Copy Literals
        LZ4_BLINDCOPY(anchor, op, length);

_next_match:
        // Encode Offset
        LZ4_WRITE_LITTLEENDIAN_16(op,(U16)(ip-ref));

        // Start Counting
        ip+=MINMATCH; ref+=MINMATCH;   // MinMatch verified
        anchor = ip;
#ifdef LZ4_MK_OPT
        while (ip<matchlimit_STEPSIZE_1)
#else
        while (ip<matchlimit-(STEPSIZE-1))
#endif
        {
            UARCH diff = AARCH(ref) ^ AARCH(ip);
            if (!diff) { ip+=STEPSIZE; ref+=STEPSIZE; continue; }
            ip += LZ4_NbCommonBytes(diff);
            goto _endCount;
        }
#ifdef LZ4_MK_OPT
        #if (LZ4_ARCH64 == 1)
        if ((ip<matchlimit_3) && (A32(ref) == A32(ip))) { ip+=4; ref+=4; }
        #endif
        if ((ip<matchlimit_1) && (A16(ref) == A16(ip))) { ip+=2; ref+=2; }
        if ((ip<matchlimit) && (*ref == *ip)) ip++;
#else
        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++;
#endif

_endCount:

        // Encode MatchLength
        len = (int)(ip - anchor);
#ifdef LZ4_MK_OPT
        if unlikely(op + (len>>8) > oend_LASTLITERALS_1) return 0; // Check output limit
#else
        if unlikely(op + (1 + LASTLITERALS) + (len>>8) > oend) return 0; // Check output limit
#endif
        if (len>=(int)ML_MASK) { *token+=ML_MASK; len-=ML_MASK; for(; len > 509 ; len-=510) { *op++ = 255; *op++ = 255; } if (len > 254) { len-=255; *op++ = 255; } *op++ = (BYTE)len; }
        else *token += (BYTE)len;

        // Test end of chunk
        if (ip > mflimit) { anchor = ip;  break; }

        // Fill table
        HashTable[LZ4_HASH64K_VALUE(ip-2)] = (U16)(ip - 2 - base);

        // Test next position
#ifdef LZ4_MK_OPT
        U32 h = LZ4_HASH64K_VALUE(ip);
        ref = base + HashTable[h];
        HashTable[h] = (U16)(ip - base);
#else
        ref = base + HashTable[LZ4_HASH64K_VALUE(ip)];
        HashTable[LZ4_HASH64K_VALUE(ip)] = (U16)(ip - base);
#endif

        if (A32(ref) == A32(ip)) { token = op++; *token=0; goto _next_match; }

        // Prepare next loop
        anchor = ip++;
        forwardH = LZ4_HASH64K_VALUE(ip);
    }

_last_literals:
    // Encode Last Literals
    {
        int lastRun = (int)(iend - anchor);
        if (op + lastRun + 1 + (lastRun-RUN_MASK+255)/255 > oend) return 0;
        if (lastRun>=(int)RUN_MASK) { *op++=(RUN_MASK<<ML_BITS); lastRun-=RUN_MASK; for(; lastRun > 254 ; 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);
}


CORE_EXPORT( int ) LZ4_compress_limitedOutput(const char* source,
    char* dest,
    int isize,
    int maxOutputSize)
{
#if HEAPMODE
    void* ctx = malloc(sizeof(struct refTables));
    int result;
    if (ctx == NULL) return 0;    // Failed allocation => compression not done
    if (isize < LZ4_64KLIMIT)
        result = LZ4_compress64kCtx(&ctx, source, dest, isize, maxOutputSize);
    else result = LZ4_compressCtx(&ctx, source, dest, isize, maxOutputSize);
    free(ctx);
    return result;
#else
    if (isize < (int)LZ4_64KLIMIT) return LZ4_compress64kCtx(NULL, source, dest, isize, maxOutputSize);
    return LZ4_compressCtx(NULL, source, dest, isize, maxOutputSize);
#endif
}

CORE_EXPORT( int ) LZ4_compress(const char* source,
    char* dest,
    int isize)
{
    return LZ4_compress_limitedOutput(source, dest, isize, LZ4_compressBound(isize));
}

//****************************
// Decompression functions
//****************************

// Note : The decoding functions LZ4_uncompress() and LZ4_uncompress_unknownOutputSize()
//      are safe against "buffer overflow" attack type.
//      They will never write nor read outside of the provided output buffers.
//      LZ4_uncompress_unknownOutputSize() also insures that it will never read outside of the input buffer.
//      LZ4_uncompress() guarantees that it will never read before source, nor beyond source + LZ4_compressBound(osize)
//      A corrupted input will produce an error result, a negative int, indicating the position of the error within input stream.

CORE_EXPORT( int ) LZ4_uncompress(const char* source,
    char* dest,
    int osize)
{
    // Local Variables
    const BYTE* restrict ip = (const BYTE*) source;
    const BYTE* ref;

    BYTE* op = (BYTE*) dest;
    BYTE* const oend = op + osize;
    BYTE* cpy;

    #ifdef LZ4_MK_OPT
        const BYTE* oend_LASTLITERALS = oend - LASTLITERALS;
        const BYTE* oend_COPYLENGTH = oend - COPYLENGTH;
        const BYTE* oend_COPYLENGTH_STEPSIZE_4 = oend - COPYLENGTH - (STEPSIZE - 4);
    #endif

    unsigned token;

    size_t dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0};
#if LZ4_ARCH64
    size_t dec64table[] = {0, 0, 0, (size_t)-1, 0, 1, 2, 3};
#endif

    // Main Loop
    while (1)
    {
        size_t length;

        // get runlength
        token = *ip++;
        if ((length=(token>>ML_BITS)) == RUN_MASK)  { size_t len; for (;(len=*ip++)==255;length+=255) { } length += len; }

        // copy literals
        cpy = op+length;
#ifdef LZ4_MK_OPT
        if (cpy>oend_COPYLENGTH)
#else
        if (cpy>oend-COPYLENGTH)
#endif
        {
            if (cpy != oend) goto _output_error;         // Error : not enough place for another match (min 4) + 5 literals
            memcpy(op, ip, length);
            ip += length;
            break;                                       // EOF
        }
        LZ4_WILDCOPY(ip, op, cpy); ip -= (op-cpy); op = cpy;

        // get offset
        LZ4_READ_LITTLEENDIAN_16(ref,cpy,ip); ip+=2;
        if unlikely(ref < (BYTE* const)dest) goto _output_error;   // Error : offset outside destination buffer

        // get matchlength
        if ((length=(token&ML_MASK)) == ML_MASK) { for (;*ip==255;length+=255) {ip++;} length += *ip++; }

        // copy repeated sequence
        if unlikely((op-ref)<STEPSIZE)
        {
#if LZ4_ARCH64
            size_t dec64 = dec64table[op-ref];
#else
            const int dec64 = 0;
#endif
            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(ref,op); }
        cpy = op + length - (STEPSIZE-4);

#ifdef LZ4_MK_OPT
        if unlikely(cpy > oend_COPYLENGTH_STEPSIZE_4)
#else
        if unlikely(cpy>oend-(COPYLENGTH)-(STEPSIZE-4))
#endif
        {
#ifdef LZ4_MK_OPT
            if (cpy > oend_LASTLITERALS) goto _output_error;    // Error : last 5 bytes must be literals
            LZ4_SECURECOPY(ref, op, oend_COPYLENGTH);
#else
            if (cpy > oend-LASTLITERALS) goto _output_error;    // Error : last 5 bytes must be literals
            LZ4_SECURECOPY(ref, op, (oend-COPYLENGTH));
#endif
            while(op<cpy) *op++=*ref++;
            op=cpy;
            continue;
        }

        LZ4_WILDCOPY(ref, op, cpy);
        op = cpy;       // correction
    }

    // end of decoding
    return (int) (((char*)ip)-source);

    // write overflow error detected
_output_error:
    return (int) (-(((char*)ip)-source));
}

CORE_EXPORT( int ) LZ4_uncompress_unknownOutputSize(
    const char* source,
    char* dest,
    int isize,
    int maxOutputSize)
{
    // Local Variables
    const BYTE* restrict ip = (const BYTE*) source;
    const BYTE* const iend = ip + isize;
    const BYTE* ref;

    BYTE* op = (BYTE*) dest;
    BYTE* const oend = op + maxOutputSize;
    BYTE* cpy;

#ifdef LZ4_MK_OPT
    const BYTE* iend_LASTLITERALS_3 = (iend-(2+1+LASTLITERALS));
    const BYTE* iend_LASTLITERALS_1 = (iend-(LASTLITERALS+1));
    const BYTE* oend_COPYLENGTH = (oend-COPYLENGTH);
    const BYTE* oend_COPYLENGTH_STEPSIZE_4 = (oend-(COPYLENGTH+(STEPSIZE-4)));
    const BYTE* oend_LASTLITERALS = (oend - LASTLITERALS);
    const BYTE* oend_MFLIMIT = (oend - MFLIMIT);
#endif

    size_t dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0};
#if LZ4_ARCH64
    size_t dec64table[] = {0, 0, 0, (size_t)-1, 0, 1, 2, 3};
#endif

    // Special case
    if unlikely(ip==iend) goto _output_error;    // A correctly formed null-compressed LZ4 must have at least one byte (token=0)

    // Main Loop
    while (1)
    {
        unsigned token;
        size_t length;

        // get runlength
        token = *ip++;
        if ((length=(token>>ML_BITS)) == RUN_MASK)
        {
            int s=255;
            while (likely(ip<iend) && (s==255)) { s=*ip++; length += s; }
        }

        // copy literals
        cpy = op+length;
#ifdef LZ4_MK_OPT
        if ((cpy>oend_MFLIMIT) || (ip+length>iend_LASTLITERALS_3))
#else
        if ((cpy>oend-MFLIMIT) || (ip+length>iend-(2+1+LASTLITERALS)))
#endif
        {
            if (cpy > oend) goto _output_error;          // Error : writes beyond output buffer
            if (ip+length != iend) goto _output_error;   // Error : LZ4 format requires to consume all input at this stage (no match within the last 11 bytes, and at least 8 remaining input bytes for another match+literals)
            memcpy(op, ip, length);
            op += length;
            break;                                       // Necessarily EOF, due to parsing restrictions
        }
        LZ4_WILDCOPY(ip, op, cpy); ip -= (op-cpy); op = cpy;

        // get offset
        LZ4_READ_LITTLEENDIAN_16(ref,cpy,ip); ip+=2;
        if unlikely(ref < (BYTE* const)dest) goto _output_error;   // Error : offset outside of destination buffer

        // get matchlength
        if ((length=(token&ML_MASK)) == ML_MASK)
        {
#ifdef LZ4_MK_OPT
            while likely(ip<iend_LASTLITERALS_1) // Error : a minimum input bytes must remain for LASTLITERALS + token
#else
            while likely(ip<iend-(LASTLITERALS+1)) // Error : a minimum input bytes must remain for LASTLITERALS + token
#endif
            {
                int s = *ip++;
                length +=s;
                if (s==255) continue;
                break;
            }
        }

        // copy repeated sequence
        if unlikely(op-ref<STEPSIZE)
        {
#if LZ4_ARCH64
            size_t dec64 = dec64table[op-ref];
#else
            const int dec64 = 0;
#endif
            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(ref,op); }
        cpy = op + length - (STEPSIZE-4);

#ifdef LZ4_MK_OPT
        if unlikely(cpy>oend_COPYLENGTH_STEPSIZE_4)
#else
        if unlikely(cpy>oend-(COPYLENGTH+(STEPSIZE-4)))
#endif
        {
#ifdef LZ4_MK_OPT
            if (cpy > oend_LASTLITERALS) goto _output_error;    // Error : last 5 bytes must be literals
            LZ4_SECURECOPY(ref, op, oend_COPYLENGTH);
#else
            if (cpy > oend-LASTLITERALS) goto _output_error;    // Error : last 5 bytes must be literals
            LZ4_SECURECOPY(ref, op, (oend-COPYLENGTH));
#endif
            while(op<cpy) *op++=*ref++;
            op=cpy;
            continue;
        }

        LZ4_WILDCOPY(ref, op, cpy);
        op=cpy;     // correction
    }

    // end of decoding
    return (int) (((char*)op)-dest);

    // write overflow error detected
_output_error:
    return (int) (-(((char*)ip)-source));
}