/*

*  xxHash - Fast Hash algorithm

*  Copyright (C) 2012-2016, 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 :

*  - xxHash homepage: http://www.xxhash.com

*  - xxHash source repository : https://github.com/Cyan4973/xxHash

*/

/* *************************************

*  Tuning parameters

***************************************/

/*!XXH_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 doesn't depend on compiler but violate C standard.

 *            It can generate buggy code on targets which do not support unaligned memory accesses.

 *            But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)

 * See http://stackoverflow.com/a/32095106/646947 for details.

 * Prefer these methods in priority order (0 > 1 > 2)

 */

#ifndef XXH_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */

#  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 XXH_FORCE_MEMORY_ACCESS 2

#  elif (defined(__INTEL_COMPILER) && !defined(WIN32)) || \

  (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) ))

#    define XXH_FORCE_MEMORY_ACCESS 1

#  endif

#endif

/*!XXH_ACCEPT_NULL_INPUT_POINTER :

 * If the input pointer is a null pointer, xxHash default behavior is to trigger a memory access error, since it is a bad pointer.

 * When this option is enabled, xxHash output for null input pointers will be the same as a null-length input.

 * By default, this option is disabled. To enable it, uncomment below define :

 */

/* #define XXH_ACCEPT_NULL_INPUT_POINTER 1 */

/*!XXH_FORCE_NATIVE_FORMAT :

 * By default, xxHash library provides endian-independant Hash values, based on little-endian convention.

 * Results are therefore identical for little-endian and big-endian CPU.

 * This comes at a performance cost for big-endian CPU, since some swapping is required to emulate little-endian format.

 * Should endian-independance be of no importance for your application, you may set the #define below to 1,

 * to improve speed for Big-endian CPU.

 * This option has no impact on Little_Endian CPU.

 */

#ifndef XXH_FORCE_NATIVE_FORMAT   /* can be defined externally */

#  define XXH_FORCE_NATIVE_FORMAT 0

#endif

/*!XXH_FORCE_ALIGN_CHECK :

 * This is a minor performance trick, only useful with lots of very small keys.

 * It means : check for aligned/unaligned input.

 * The check costs one initial branch per hash; set to 0 when the input data

 * is guaranteed to be aligned.

 */

#ifndef XXH_FORCE_ALIGN_CHECK /* can be defined externally */

#  if defined(__i386) || defined(_M_IX86) || defined(__x86_64__) || defined(_M_X64)

#    define XXH_FORCE_ALIGN_CHECK 0

#  else

#    define XXH_FORCE_ALIGN_CHECK 1

#  endif

#endif

/* *************************************

*  Includes & Memory related functions

***************************************/

/* Modify the local functions below should you wish to use some other memory routines */

/* for malloc(), free() */

#include <stdlib.h>

static void* XXH_malloc(size_t s) { return malloc(s); }

static void  XXH_free  (void* p)  { free(p); }

/* for memcpy() */

#include <string.h>

static void* XXH_memcpy(void* dest, const void* src, size_t size) { return memcpy(dest,src,size); }

#define XXH_STATIC_LINKING_ONLY

#include "xxhash.h"

/* *************************************

*  Compiler Specific Options

***************************************/

#ifdef _MSC_VER    /* Visual Studio */

#  pragma warning(disable : 4127)      /* disable: C4127: conditional expression is constant */

#  define FORCE_INLINE static __forceinline

#else

#  if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */

#    ifdef __GNUC__

#      define FORCE_INLINE static inline __attribute__((always_inline))

#    else

#      define FORCE_INLINE static inline

#    endif

#  else

#    define FORCE_INLINE static

#  endif /* __STDC_VERSION__ */

#endif

/* *************************************

*  Basic Types

***************************************/

#ifndef MEM_MODULE

# define MEM_MODULE

# if !defined (__VMS) && (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;

#  else

    typedef unsigned char      BYTE;

    typedef unsigned short     U16;

    typedef unsigned int       U32;

    typedef   signed int       S32;

    typedef unsigned long long U64;   /* if your compiler doesn't support unsigned long long, replace by another 64-bit type here. Note that xxhash.h will also need to be updated. */

#  endif

#endif

#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))

/* Force direct memory access. Only works on CPU which support unaligned memory access in hardware */

static U32 XXH_read32(const void* memPtr) { return *(const U32*) memPtr; }

static U64 XXH_read64(const void* memPtr) { return *(const U64*) memPtr; }

#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_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 { U32 u32; U64 u64; } __attribute__((packed)) unalign;

static U32 XXH_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }

static U64 XXH_read64(const void* ptr) { return ((const unalign*)ptr)->u64; }

#else

/* portable and safe solution. Generally efficient.

 * see : http://stackoverflow.com/a/32095106/646947

 */

static U32 XXH_read32(const void* memPtr)

{

    U32 val;

    memcpy(&val, memPtr, sizeof(val));

    return val;

}

static U64 XXH_read64(const void* memPtr)

{

    U64 val;

    memcpy(&val, memPtr, sizeof(val));

    return val;

}

#endif   /* XXH_FORCE_DIRECT_MEMORY_ACCESS */

/* ****************************************

*  Compiler-specific Functions and Macros

******************************************/

#define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)

/* Note : although _rotl exists for minGW (GCC under windows), performance seems poor */

#if defined(_MSC_VER)

#  define XXH_rotl32(x,r) _rotl(x,r)

#  define XXH_rotl64(x,r) _rotl64(x,r)

#else

#  define XXH_rotl32(x,r) ((x << r) | (x >> (32 - r)))

#  define XXH_rotl64(x,r) ((x << r) | (x >> (64 - r)))

#endif

#if defined(_MSC_VER)     /* Visual Studio */

#  define XXH_swap32 _byteswap_ulong

#  define XXH_swap64 _byteswap_uint64

#elif GCC_VERSION >= 403

#  define XXH_swap32 __builtin_bswap32

#  define XXH_swap64 __builtin_bswap64

#else

static U32 XXH_swap32 (U32 x)

{

    return  ((x << 24) & 0xff000000 ) |

            ((x <<  8) & 0x00ff0000 ) |

            ((x >>  8) & 0x0000ff00 ) |

            ((x >> 24) & 0x000000ff );

}

static U64 XXH_swap64 (U64 x)

{

    return  ((x << 56) & 0xff00000000000000ULL) |

            ((x << 40) & 0x00ff000000000000ULL) |

            ((x << 24) & 0x0000ff0000000000ULL) |

            ((x << 8)  & 0x000000ff00000000ULL) |

            ((x >> 8)  & 0x00000000ff000000ULL) |

            ((x >> 24) & 0x0000000000ff0000ULL) |

            ((x >> 40) & 0x000000000000ff00ULL) |

            ((x >> 56) & 0x00000000000000ffULL);

}

#endif

/* *************************************

*  Architecture Macros

***************************************/

typedef enum { XXH_bigEndian=0, XXH_littleEndian=1 } XXH_endianess;

/* XXH_CPU_LITTLE_ENDIAN can be defined externally, for example on the compiler command line */

#ifndef XXH_CPU_LITTLE_ENDIAN

    static const int g_one = 1;

#   define XXH_CPU_LITTLE_ENDIAN   (*(const char*)(&g_one))

#endif

/* ***************************

*  Memory reads

*****************************/

typedef enum { XXH_aligned, XXH_unaligned } XXH_alignment;

FORCE_INLINE U32 XXH_readLE32_align(const void* ptr, XXH_endianess endian, XXH_alignment align)

{

    if (align==XXH_unaligned)

        return endian==XXH_littleEndian ? XXH_read32(ptr) : XXH_swap32(XXH_read32(ptr));

    else

        return endian==XXH_littleEndian ? *(const U32*)ptr : XXH_swap32(*(const U32*)ptr);

}

FORCE_INLINE U32 XXH_readLE32(const void* ptr, XXH_endianess endian)

{

    return XXH_readLE32_align(ptr, endian, XXH_unaligned);

}

static U32 XXH_readBE32(const void* ptr)

{

    return XXH_CPU_LITTLE_ENDIAN ? XXH_swap32(XXH_read32(ptr)) : XXH_read32(ptr);

}

FORCE_INLINE U64 XXH_readLE64_align(const void* ptr, XXH_endianess endian, XXH_alignment align)

{

    if (align==XXH_unaligned)

        return endian==XXH_littleEndian ? XXH_read64(ptr) : XXH_swap64(XXH_read64(ptr));

    else

        return endian==XXH_littleEndian ? *(const U64*)ptr : XXH_swap64(*(const U64*)ptr);

}

FORCE_INLINE U64 XXH_readLE64(const void* ptr, XXH_endianess endian)

{

    return XXH_readLE64_align(ptr, endian, XXH_unaligned);

}

static U64 XXH_readBE64(const void* ptr)

{

    return XXH_CPU_LITTLE_ENDIAN ? XXH_swap64(XXH_read64(ptr)) : XXH_read64(ptr);

}

/* *************************************

*  Macros

***************************************/

#define XXH_STATIC_ASSERT(c)   { enum { XXH_static_assert = 1/(int)(!!(c)) }; }    /* use only *after* variable declarations */

/* *************************************

*  Constants

***************************************/

static const U32 PRIME32_1 = 2654435761U;

static const U32 PRIME32_2 = 2246822519U;

static const U32 PRIME32_3 = 3266489917U;

static const U32 PRIME32_4 =  668265263U;

static const U32 PRIME32_5 =  374761393U;

static const U64 PRIME64_1 = 11400714785074694791ULL;

static const U64 PRIME64_2 = 14029467366897019727ULL;

static const U64 PRIME64_3 =  1609587929392839161ULL;

static const U64 PRIME64_4 =  9650029242287828579ULL;

static const U64 PRIME64_5 =  2870177450012600261ULL;

XXH_PUBLIC_API unsigned XXH_versionNumber (void) { return XXH_VERSION_NUMBER; }

/* **************************

*  Utils

****************************/

XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* restrict dstState, const XXH32_state_t* restrict srcState)

{

    memcpy(dstState, srcState, sizeof(*dstState));

}

XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* restrict dstState, const XXH64_state_t* restrict srcState)

{

    memcpy(dstState, srcState, sizeof(*dstState));

}

/* ***************************

*  Simple Hash Functions

*****************************/

static U32 XXH32_round(U32 seed, U32 input)

{

    seed += input * PRIME32_2;

    seed  = XXH_rotl32(seed, 13);

    seed *= PRIME32_1;

    return seed;

}

FORCE_INLINE U32 XXH32_endian_align(const void* input, size_t len, U32 seed, XXH_endianess endian, XXH_alignment align)

{

    const BYTE* p = (const BYTE*)input;

    const BYTE* bEnd = p + len;

    U32 h32;

#define XXH_get32bits(p) XXH_readLE32_align(p, endian, align)

#ifdef XXH_ACCEPT_NULL_INPUT_POINTER

    if (p==NULL) {

        len=0;

        bEnd=p=(const BYTE*)(size_t)16;

    }

#endif

    if (len>=16) {

        const BYTE* const limit = bEnd - 16;

        U32 v1 = seed + PRIME32_1 + PRIME32_2;

        U32 v2 = seed + PRIME32_2;

        U32 v3 = seed + 0;

        U32 v4 = seed - PRIME32_1;

        do {

            v1 = XXH32_round(v1, XXH_get32bits(p)); p+=4;

            v2 = XXH32_round(v2, XXH_get32bits(p)); p+=4;

            v3 = XXH32_round(v3, XXH_get32bits(p)); p+=4;

            v4 = XXH32_round(v4, XXH_get32bits(p)); p+=4;

        } while (p<=limit);

        h32 = XXH_rotl32(v1, 1) + XXH_rotl32(v2, 7) + XXH_rotl32(v3, 12) + XXH_rotl32(v4, 18);

    } else {

        h32  = seed + PRIME32_5;

    }

    h32 += (U32) len;

    while (p+4<=bEnd) {

        h32 += XXH_get32bits(p) * PRIME32_3;

        h32  = XXH_rotl32(h32, 17) * PRIME32_4 ;

        p+=4;

    }

    while (p<bEnd) {

        h32 += (*p) * PRIME32_5;

        h32 = XXH_rotl32(h32, 11) * PRIME32_1 ;

        p++;

    }

    h32 ^= h32 >> 15;

    h32 *= PRIME32_2;

    h32 ^= h32 >> 13;

    h32 *= PRIME32_3;

    h32 ^= h32 >> 16;

    return h32;

}

XXH_PUBLIC_API unsigned int XXH32 (const void* input, size_t len, unsigned int seed)

{

#if 0

    /* Simple version, good for code maintenance, but unfortunately slow for small inputs */

    XXH32_CREATESTATE_STATIC(state);

    XXH32_reset(state, seed);

    XXH32_update(state, input, len);

    return XXH32_digest(state);

#else

    XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;

    if (XXH_FORCE_ALIGN_CHECK) {

        if ((((size_t)input) & 3) == 0) {   /* Input is 4-bytes aligned, leverage the speed benefit */

            if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)

                return XXH32_endian_align(input, len, seed, XXH_littleEndian, XXH_aligned);

            else

                return XXH32_endian_align(input, len, seed, XXH_bigEndian, XXH_aligned);

    }   }

    if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)

        return XXH32_endian_align(input, len, seed, XXH_littleEndian, XXH_unaligned);

    else

        return XXH32_endian_align(input, len, seed, XXH_bigEndian, XXH_unaligned);

#endif

}

static U64 XXH64_round(U64 acc, U64 input)

{

    acc += input * PRIME64_2;

    acc  = XXH_rotl64(acc, 31);

    acc *= PRIME64_1;

    return acc;

}

static U64 XXH64_mergeRound(U64 acc, U64 val)

{

    val  = XXH64_round(0, val);

    acc ^= val;

    acc  = acc * PRIME64_1 + PRIME64_4;

    return acc;

}

FORCE_INLINE U64 XXH64_endian_align(const void* input, size_t len, U64 seed, XXH_endianess endian, XXH_alignment align)

{

    const BYTE* p = (const BYTE*)input;

    const BYTE* const bEnd = p + len;

    U64 h64;

#define XXH_get64bits(p) XXH_readLE64_align(p, endian, align)

#ifdef XXH_ACCEPT_NULL_INPUT_POINTER

    if (p==NULL) {

        len=0;

        bEnd=p=(const BYTE*)(size_t)32;

    }

#endif

    if (len>=32) {

        const BYTE* const limit = bEnd - 32;

        U64 v1 = seed + PRIME64_1 + PRIME64_2;

        U64 v2 = seed + PRIME64_2;

        U64 v3 = seed + 0;

        U64 v4 = seed - PRIME64_1;

        do {

            v1 = XXH64_round(v1, XXH_get64bits(p)); p+=8;

            v2 = XXH64_round(v2, XXH_get64bits(p)); p+=8;

            v3 = XXH64_round(v3, XXH_get64bits(p)); p+=8;

            v4 = XXH64_round(v4, XXH_get64bits(p)); p+=8;

        } while (p<=limit);

        h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);

        h64 = XXH64_mergeRound(h64, v1);

        h64 = XXH64_mergeRound(h64, v2);

        h64 = XXH64_mergeRound(h64, v3);

        h64 = XXH64_mergeRound(h64, v4);

    } else {

        h64  = seed + PRIME64_5;

    }

    h64 += (U64) len;

    while (p+8<=bEnd) {

        U64 const k1 = XXH64_round(0, XXH_get64bits(p));

        h64 ^= k1;

        h64  = XXH_rotl64(h64,27) * PRIME64_1 + PRIME64_4;

        p+=8;

    }

    if (p+4<=bEnd) {

        h64 ^= (U64)(XXH_get32bits(p)) * PRIME64_1;

        h64 = XXH_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;

        p+=4;

    }

    while (p<bEnd) {

        h64 ^= (*p) * PRIME64_5;

        h64 = XXH_rotl64(h64, 11) * PRIME64_1;

        p++;

    }

    h64 ^= h64 >> 33;

    h64 *= PRIME64_2;

    h64 ^= h64 >> 29;

    h64 *= PRIME64_3;

    h64 ^= h64 >> 32;

    return h64;

}

XXH_PUBLIC_API unsigned long long XXH64 (const void* input, size_t len, unsigned long long seed)

{

#if 0

    /* Simple version, good for code maintenance, but unfortunately slow for small inputs */

    XXH64_CREATESTATE_STATIC(state);

    XXH64_reset(state, seed);

    XXH64_update(state, input, len);

    return XXH64_digest(state);

#else

    XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;

    if (XXH_FORCE_ALIGN_CHECK) {

        if ((((size_t)input) & 7)==0) {  /* Input is aligned, let's leverage the speed advantage */

            if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)

                return XXH64_endian_align(input, len, seed, XXH_littleEndian, XXH_aligned);

            else

                return XXH64_endian_align(input, len, seed, XXH_bigEndian, XXH_aligned);

    }   }

    if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)

        return XXH64_endian_align(input, len, seed, XXH_littleEndian, XXH_unaligned);

    else

        return XXH64_endian_align(input, len, seed, XXH_bigEndian, XXH_unaligned);

#endif

}