glusterfs

1
/*
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*  xxHash - Fast Hash algorithm
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*  Copyright (C) 2012-2016, Yann Collet
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*
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*  BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
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*
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*  Redistribution and use in source and binary forms, with or without
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*  modification, are permitted provided that the following conditions are
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*  met:
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*
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*  * Redistributions of source code must retain the above copyright
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*  notice, this list of conditions and the following disclaimer.
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*  * Redistributions in binary form must reproduce the above
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*  copyright notice, this list of conditions and the following disclaimer
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*  in the documentation and/or other materials provided with the
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*  distribution.
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*
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*  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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*  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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*  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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*  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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*  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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*  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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*  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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*  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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*  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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*  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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*  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*  You can contact the author at :
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*  - xxHash homepage: http://www.xxhash.com
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*  - xxHash source repository : https://github.com/Cyan4973/xxHash
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*/
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35

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/* *************************************
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*  Tuning parameters
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***************************************/
39
/*!XXH_FORCE_MEMORY_ACCESS :
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 * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
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 * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
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 * The below switch allow to select different access method for improved performance.
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 * Method 0 (default) : use `memcpy()`. Safe and portable.
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 * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
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 *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
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 * Method 2 : direct access. This method doesn't depend on compiler but violate C standard.
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 *            It can generate buggy code on targets which do not support unaligned memory accesses.
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 *            But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
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 * See http://stackoverflow.com/a/32095106/646947 for details.
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 * Prefer these methods in priority order (0 > 1 > 2)
51
 */
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#ifndef XXH_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
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#  if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) \
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                        || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) \
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                        || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
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#    define XXH_FORCE_MEMORY_ACCESS 2
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#  elif (defined(__INTEL_COMPILER) && !defined(_WIN32)) || \
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  (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) \
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                    || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) \
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                    || defined(__ARM_ARCH_7S__) ))
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#    define XXH_FORCE_MEMORY_ACCESS 1
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#  endif
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#endif
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/*!XXH_ACCEPT_NULL_INPUT_POINTER :
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 * If input pointer is NULL, xxHash default behavior is to dereference it, triggering a segfault.
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 * When this macro is enabled, xxHash actively checks input for null pointer.
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 * It it is, result for null input pointers is the same as a null-length input.
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 */
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#ifndef XXH_ACCEPT_NULL_INPUT_POINTER   /* can be defined externally */
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#  define XXH_ACCEPT_NULL_INPUT_POINTER 0
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#endif
73

74
/*!XXH_FORCE_NATIVE_FORMAT :
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 * By default, xxHash library provides endian-independent Hash values, based on little-endian convention.
76
 * Results are therefore identical for little-endian and big-endian CPU.
77
 * This comes at a performance cost for big-endian CPU, since some swapping is required to emulate little-endian format.
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 * Should endian-independence be of no importance for your application, you may set the #define below to 1,
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 * to improve speed for Big-endian CPU.
80
 * This option has no impact on Little_Endian CPU.
81
 */
82
#ifndef XXH_FORCE_NATIVE_FORMAT   /* can be defined externally */
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#  define XXH_FORCE_NATIVE_FORMAT 0
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#endif
85

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/*!XXH_FORCE_ALIGN_CHECK :
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 * This is a minor performance trick, only useful with lots of very small keys.
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 * It means : check for aligned/unaligned input.
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 * The check costs one initial branch per hash;
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 * set it to 0 when the input is guaranteed to be aligned,
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 * or when alignment doesn't matter for performance.
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 */
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#ifndef XXH_FORCE_ALIGN_CHECK /* can be defined externally */
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#  if defined(__i386) || defined(_M_IX86) || defined(__x86_64__) || defined(_M_X64)
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#    define XXH_FORCE_ALIGN_CHECK 0
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#  else
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#    define XXH_FORCE_ALIGN_CHECK 1
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#  endif
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#endif
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/* *************************************
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*  Includes & Memory related functions
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***************************************/
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/*! Modify the local functions below should you wish to use some other memory routines
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*   for malloc(), free() */
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#include <stdlib.h>
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static void* XXH_malloc(size_t s) { return malloc(s); }
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static void  XXH_free  (void* p)  { free(p); }
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/*! and for memcpy() */
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#include <string.h>
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static void* XXH_memcpy(void* dest, const void* src, size_t size) { return memcpy(dest,src,size); }
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114
#include <assert.h>   /* assert */
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116
#define XXH_STATIC_LINKING_ONLY
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#include "xxhash.h"
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119

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/* *************************************
121
*  Compiler Specific Options
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***************************************/
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#ifdef _MSC_VER    /* Visual Studio */
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#  pragma warning(disable : 4127)      /* disable: C4127: conditional expression is constant */
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#  define FORCE_INLINE static __forceinline
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#else
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#  if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
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#    ifdef __GNUC__
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#      define FORCE_INLINE static inline __attribute__((always_inline))
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#    else
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#      define FORCE_INLINE static inline
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#    endif
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#  else
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#    define FORCE_INLINE static
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#  endif /* __STDC_VERSION__ */
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#endif
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138

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/* *************************************
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*  Basic Types
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***************************************/
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#ifndef MEM_MODULE
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# if !defined (__VMS) \
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  && (defined (__cplusplus) \
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  || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
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#   include <stdint.h>
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    typedef uint8_t  BYTE;
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    typedef uint16_t U16;
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    typedef uint32_t U32;
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# else
151
    typedef unsigned char      BYTE;
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    typedef unsigned short     U16;
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    typedef unsigned int       U32;
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# endif
155
#endif
156

157
#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))
158

159
/* Force direct memory access. Only works on CPU which support unaligned memory access in hardware */
160
static U32 XXH_read32(const void* memPtr) { return *(const U32*) memPtr; }
161

162
#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))
163

164
/* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
165
/* currently only defined for gcc and icc */
166
typedef union { U32 u32; } __attribute__((packed)) unalign;
167
static U32 XXH_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
168

169
#else
170

171
/* portable and safe solution. Generally efficient.
172
 * see : http://stackoverflow.com/a/32095106/646947
173
 */
174
static U32 XXH_read32(const void* memPtr)
175
{
176
    U32 val;
177
    memcpy(&val, memPtr, sizeof(val));
178
    return val;
179
}
180

181
#endif   /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
182

183

184
/* ****************************************
185
*  Compiler-specific Functions and Macros
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******************************************/
187
#define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
188

189
/* Note : although _rotl exists for minGW (GCC under windows), performance seems poor */
190
#if defined(_MSC_VER)
191
#  define XXH_rotl32(x,r) _rotl(x,r)
192
#  define XXH_rotl64(x,r) _rotl64(x,r)
193
#else
194
#  define XXH_rotl32(x,r) ((x << r) | (x >> (32 - r)))
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#  define XXH_rotl64(x,r) ((x << r) | (x >> (64 - r)))
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#endif
197

198
#if defined(_MSC_VER)     /* Visual Studio */
199
#  define XXH_swap32 _byteswap_ulong
200
#elif GCC_VERSION >= 403
201
#  define XXH_swap32 __builtin_bswap32
202
#else
203
static U32 XXH_swap32 (U32 x)
204
{
205
    return  ((x << 24) & 0xff000000 ) |
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            ((x <<  8) & 0x00ff0000 ) |
207
            ((x >>  8) & 0x0000ff00 ) |
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            ((x >> 24) & 0x000000ff );
209
}
210
#endif
211

212

213
/* *************************************
214
*  Architecture Macros
215
***************************************/
216
typedef enum { XXH_bigEndian=0, XXH_littleEndian=1 } XXH_endianess;
217

218
/* XXH_CPU_LITTLE_ENDIAN can be defined externally, for example on the compiler command line */
219
#ifndef XXH_CPU_LITTLE_ENDIAN
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static int XXH_isLittleEndian(void)
221
{
222
    const union { U32 u; BYTE c[4]; } one = { 1 };   /* don't use static : performance detrimental  */
223
    return one.c[0];
224
}
225
#   define XXH_CPU_LITTLE_ENDIAN   XXH_isLittleEndian()
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#endif
227

228

229
/* ***************************
230
*  Memory reads
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*****************************/
232
typedef enum { XXH_aligned, XXH_unaligned } XXH_alignment;
233

234
FORCE_INLINE U32 XXH_readLE32_align(const void* ptr, XXH_endianess endian, XXH_alignment align)
235
{
236
    if (align==XXH_unaligned)
237
        return endian==XXH_littleEndian ? XXH_read32(ptr) : XXH_swap32(XXH_read32(ptr));
238
    else
239
        return endian==XXH_littleEndian ? *(const U32*)ptr : XXH_swap32(*(const U32*)ptr);
240
}
241

242
FORCE_INLINE U32 XXH_readLE32(const void* ptr, XXH_endianess endian)
243
{
244
    return XXH_readLE32_align(ptr, endian, XXH_unaligned);
245
}
246

247
static U32 XXH_readBE32(const void* ptr)
248
{
249
    return XXH_CPU_LITTLE_ENDIAN ? XXH_swap32(XXH_read32(ptr)) : XXH_read32(ptr);
250
}
251

252

253
/* *************************************
254
*  Macros
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***************************************/
256
#define XXH_STATIC_ASSERT(c)  { enum { XXH_sa = 1/(int)(!!(c)) }; }  /* use after variable declarations */
257
XXH_PUBLIC_API unsigned XXH_versionNumber (void) { return XXH_VERSION_NUMBER; }
258

259

260
/* *******************************************************************
261
*  32-bit hash functions
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*********************************************************************/
263
static const U32 PRIME32_1 = 2654435761U;
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static const U32 PRIME32_2 = 2246822519U;
265
static const U32 PRIME32_3 = 3266489917U;
266
static const U32 PRIME32_4 =  668265263U;
267
static const U32 PRIME32_5 =  374761393U;
268

269
static U32 XXH32_round(U32 seed, U32 input)
270
{
271
    seed += input * PRIME32_2;
272
    seed  = XXH_rotl32(seed, 13);
273
    seed *= PRIME32_1;
274
    return seed;
275
}
276

277
/* mix all bits */
278
static U32 XXH32_avalanche(U32 h32)
279
{
280
    h32 ^= h32 >> 15;
281
    h32 *= PRIME32_2;
282
    h32 ^= h32 >> 13;
283
    h32 *= PRIME32_3;
284
    h32 ^= h32 >> 16;
285
    return(h32);
286
}
287

288
#define XXH_get32bits(p) XXH_readLE32_align(p, endian, align)
289

290
static U32
291
XXH32_finalize(U32 h32, const void* ptr, size_t len,
292
                XXH_endianess endian, XXH_alignment align)
293

294
{
295
    const BYTE* p = (const BYTE*)ptr;
296
#define PROCESS1             \
297
    h32 += (*p) * PRIME32_5; \
298
    p++;                     \
299
    h32 = XXH_rotl32(h32, 11) * PRIME32_1 ;
300

301
#define PROCESS4                         \
302
    h32 += XXH_get32bits(p) * PRIME32_3; \
303
    p+=4;                                \
304
    h32  = XXH_rotl32(h32, 17) * PRIME32_4 ;
305

306
    switch(len&15)  /* or switch(bEnd - p) */
307
    {
308
      case 12:      PROCESS4;
309
                    /* fallthrough */
310
      case 8:       PROCESS4;
311
                    /* fallthrough */
312
      case 4:       PROCESS4;
313
                    return XXH32_avalanche(h32);
314

315
      case 13:      PROCESS4;
316
                    /* fallthrough */
317
      case 9:       PROCESS4;
318
                    /* fallthrough */
319
      case 5:       PROCESS4;
320
                    PROCESS1;
321
                    return XXH32_avalanche(h32);
322

323
      case 14:      PROCESS4;
324
                    /* fallthrough */
325
      case 10:      PROCESS4;
326
                    /* fallthrough */
327
      case 6:       PROCESS4;
328
                    PROCESS1;
329
                    PROCESS1;
330
                    return XXH32_avalanche(h32);
331

332
      case 15:      PROCESS4;
333
                    /* fallthrough */
334
      case 11:      PROCESS4;
335
                    /* fallthrough */
336
      case 7:       PROCESS4;
337
                    /* fallthrough */
338
      case 3:       PROCESS1;
339
                    /* fallthrough */
340
      case 2:       PROCESS1;
341
                    /* fallthrough */
342
      case 1:       PROCESS1;
343
                    /* fallthrough */
344
      case 0:       return XXH32_avalanche(h32);
345
    }
346
    assert(0);
347
    return h32;   /* reaching this point is deemed impossible */
348
}
349

350

351
FORCE_INLINE U32
352
XXH32_endian_align(const void* input, size_t len, U32 seed,
353
                    XXH_endianess endian, XXH_alignment align)
354
{
355
    const BYTE* p = (const BYTE*)input;
356
    const BYTE* bEnd = p + len;
357
    U32 h32;
358

359
#if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && (XXH_ACCEPT_NULL_INPUT_POINTER>=1)
360
    if (p==NULL) {
361
        len=0;
362
        bEnd=p=(const BYTE*)(size_t)16;
363
    }
364
#endif
365

366
    if (len>=16) {
367
        const BYTE* const limit = bEnd - 15;
368
        U32 v1 = seed + PRIME32_1 + PRIME32_2;
369
        U32 v2 = seed + PRIME32_2;
370
        U32 v3 = seed + 0;
371
        U32 v4 = seed - PRIME32_1;
372

373
        do {
374
            v1 = XXH32_round(v1, XXH_get32bits(p)); p+=4;
375
            v2 = XXH32_round(v2, XXH_get32bits(p)); p+=4;
376
            v3 = XXH32_round(v3, XXH_get32bits(p)); p+=4;
377
            v4 = XXH32_round(v4, XXH_get32bits(p)); p+=4;
378
        } while (p < limit);
379

380
        h32 = XXH_rotl32(v1, 1)  + XXH_rotl32(v2, 7)
381
            + XXH_rotl32(v3, 12) + XXH_rotl32(v4, 18);
382
    } else {
383
        h32  = seed + PRIME32_5;
384
    }
385

386
    h32 += (U32)len;
387

388
    return XXH32_finalize(h32, p, len&15, endian, align);
389
}
390

391

392
XXH_PUBLIC_API unsigned int XXH32 (const void* input, size_t len, unsigned int seed)
393
{
394
#if 0
395
    /* Simple version, good for code maintenance, but unfortunately slow for small inputs */
396
    XXH32_state_t state;
397
    XXH32_reset(&state, seed);
398
    XXH32_update(&state, input, len);
399
    return XXH32_digest(&state);
400
#else
401
    XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
402

403
    if (XXH_FORCE_ALIGN_CHECK) {
404
        if ((((size_t)input) & 3) == 0) {   /* Input is 4-bytes aligned, leverage the speed benefit */
405
            if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
406
                return XXH32_endian_align(input, len, seed, XXH_littleEndian, XXH_aligned);
407
            else
408
                return XXH32_endian_align(input, len, seed, XXH_bigEndian, XXH_aligned);
409
    }   }
410

411
    if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
412
        return XXH32_endian_align(input, len, seed, XXH_littleEndian, XXH_unaligned);
413
    else
414
        return XXH32_endian_align(input, len, seed, XXH_bigEndian, XXH_unaligned);
415
#endif
416
}
417

418

419

420
/*======   Hash streaming   ======*/
421

422
XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void)
423
{
424
    return (XXH32_state_t*)XXH_malloc(sizeof(XXH32_state_t));
425
}
426
XXH_PUBLIC_API XXH_errorcode XXH32_freeState(XXH32_state_t* statePtr)
427
{
428
    XXH_free(statePtr);
429
    return XXH_OK;
430
}
431

432
XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* dstState, const XXH32_state_t* srcState)
433
{
434
    memcpy(dstState, srcState, sizeof(*dstState));
435
}
436

437
XXH_PUBLIC_API XXH_errorcode XXH32_reset(XXH32_state_t* statePtr, unsigned int seed)
438
{
439
    XXH32_state_t state;   /* using a local state to memcpy() in order to avoid strict-aliasing warnings */
440
    memset(&state, 0, sizeof(state));
441
    state.v1 = seed + PRIME32_1 + PRIME32_2;
442
    state.v2 = seed + PRIME32_2;
443
    state.v3 = seed + 0;
444
    state.v4 = seed - PRIME32_1;
445
    /* do not write into reserved, planned to be removed in a future version */
446
    memcpy(statePtr, &state, sizeof(state) - sizeof(state.reserved));
447
    return XXH_OK;
448
}
449

450

451
FORCE_INLINE
452
XXH_errorcode XXH32_update_endian (XXH32_state_t* state, const void* input, size_t len, XXH_endianess endian)
453
{
454
    const BYTE* p = (const BYTE*)input;
455
    const BYTE* const bEnd = p + len;
456

457
    if (input==NULL)
458
#if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && (XXH_ACCEPT_NULL_INPUT_POINTER>=1)
459
        return XXH_OK;
460
#else
461
        return XXH_ERROR;
462
#endif
463

464
    state->total_len_32 += (unsigned)len;
465
    state->large_len |= (len>=16) | (state->total_len_32>=16);
466

467
    if (state->memsize + len < 16)  {   /* fill in tmp buffer */
468
        XXH_memcpy((BYTE*)(state->mem32) + state->memsize, input, len);
469
        state->memsize += (unsigned)len;
470
        return XXH_OK;
471
    }
472

473
    if (state->memsize) {   /* some data left from previous update */
474
        XXH_memcpy((BYTE*)(state->mem32) + state->memsize, input, 16-state->memsize);
475
        {   const U32* p32 = state->mem32;
476
            state->v1 = XXH32_round(state->v1, XXH_readLE32(p32, endian)); p32++;
477
            state->v2 = XXH32_round(state->v2, XXH_readLE32(p32, endian)); p32++;
478
            state->v3 = XXH32_round(state->v3, XXH_readLE32(p32, endian)); p32++;
479
            state->v4 = XXH32_round(state->v4, XXH_readLE32(p32, endian));
480
        }
481
        p += 16-state->memsize;
482
        state->memsize = 0;
483
    }
484

485
    if (p <= bEnd-16) {
486
        const BYTE* const limit = bEnd - 16;
487
        U32 v1 = state->v1;
488
        U32 v2 = state->v2;
489
        U32 v3 = state->v3;
490
        U32 v4 = state->v4;
491

492
        do {
493
            v1 = XXH32_round(v1, XXH_readLE32(p, endian)); p+=4;
494
            v2 = XXH32_round(v2, XXH_readLE32(p, endian)); p+=4;
495
            v3 = XXH32_round(v3, XXH_readLE32(p, endian)); p+=4;
496
            v4 = XXH32_round(v4, XXH_readLE32(p, endian)); p+=4;
497
        } while (p<=limit);
498

499
        state->v1 = v1;
500
        state->v2 = v2;
501
        state->v3 = v3;
502
        state->v4 = v4;
503
    }
504

505
    if (p < bEnd) {
506
        XXH_memcpy(state->mem32, p, (size_t)(bEnd-p));
507
        state->memsize = (unsigned)(bEnd-p);
508
    }
509

510
    return XXH_OK;
511
}
512

513

514
XXH_PUBLIC_API XXH_errorcode XXH32_update (XXH32_state_t* state_in, const void* input, size_t len)
515
{
516
    XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
517

518
    if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
519
        return XXH32_update_endian(state_in, input, len, XXH_littleEndian);
520
    else
521
        return XXH32_update_endian(state_in, input, len, XXH_bigEndian);
522
}
523

524

525
FORCE_INLINE U32
526
XXH32_digest_endian (const XXH32_state_t* state, XXH_endianess endian)
527
{
528
    U32 h32;
529

530
    if (state->large_len) {
531
        h32 = XXH_rotl32(state->v1, 1)
532
            + XXH_rotl32(state->v2, 7)
533
            + XXH_rotl32(state->v3, 12)
534
            + XXH_rotl32(state->v4, 18);
535
    } else {
536
        h32 = state->v3 /* == seed */ + PRIME32_5;
537
    }
538

539
    h32 += state->total_len_32;
540

541
    return XXH32_finalize(h32, state->mem32, state->memsize, endian, XXH_aligned);
542
}
543

544

545
XXH_PUBLIC_API unsigned int XXH32_digest (const XXH32_state_t* state_in)
546
{
547
    XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
548

549
    if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
550
        return XXH32_digest_endian(state_in, XXH_littleEndian);
551
    else
552
        return XXH32_digest_endian(state_in, XXH_bigEndian);
553
}
554

555

556
/*======   Canonical representation   ======*/
557

558
/*! Default XXH result types are basic unsigned 32 and 64 bits.
559
*   The canonical representation follows human-readable write convention, aka big-endian (large digits first).
560
*   These functions allow transformation of hash result into and from its canonical format.
561
*   This way, hash values can be written into a file or buffer, remaining comparable across different systems.
562
*/
563

564
XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash)
565
{
566
    XXH_STATIC_ASSERT(sizeof(XXH32_canonical_t) == sizeof(XXH32_hash_t));
567
    if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap32(hash);
568
    memcpy(dst, &hash, sizeof(*dst));
569
}
570

571
XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src)
572
{
573
    return XXH_readBE32(src);
574
}
575

576

577
#ifndef XXH_NO_LONG_LONG
578

579
/* *******************************************************************
580
*  64-bit hash functions
581
*********************************************************************/
582

583
/*======   Memory access   ======*/
584

585
#ifndef MEM_MODULE
586
# define MEM_MODULE
587
# if !defined (__VMS) \
588
  && (defined (__cplusplus) \
589
  || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
590
#   include <stdint.h>
591
    typedef uint64_t U64;
592
# else
593
    /* if compiler doesn't support unsigned long long, replace by another 64-bit type */
594
    typedef unsigned long long U64;
595
# endif
596
#endif
597

598

599
#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))
600

601
/* Force direct memory access. Only works on CPU which support unaligned memory access in hardware */
602
static U64 XXH_read64(const void* memPtr) { return *(const U64*) memPtr; }
603

604
#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))
605

606
/* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
607
/* currently only defined for gcc and icc */
608
typedef union { U32 u32; U64 u64; } __attribute__((packed)) unalign64;
609
static U64 XXH_read64(const void* ptr) { return ((const unalign64*)ptr)->u64; }
610

611
#else
612

613
/* portable and safe solution. Generally efficient.
614
 * see : http://stackoverflow.com/a/32095106/646947
615
 */
616

617
static U64 XXH_read64(const void* memPtr)
618
{
619
    U64 val;
620
    memcpy(&val, memPtr, sizeof(val));
621
    return val;
622
}
623

624
#endif   /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
625

626
#if defined(_MSC_VER)     /* Visual Studio */
627
#  define XXH_swap64 _byteswap_uint64
628
#elif GCC_VERSION >= 403
629
#  define XXH_swap64 __builtin_bswap64
630
#else
631
static U64 XXH_swap64 (U64 x)
632
{
633
    return  ((x << 56) & 0xff00000000000000ULL) |
634
            ((x << 40) & 0x00ff000000000000ULL) |
635
            ((x << 24) & 0x0000ff0000000000ULL) |
636
            ((x << 8)  & 0x000000ff00000000ULL) |
637
            ((x >> 8)  & 0x00000000ff000000ULL) |
638
            ((x >> 24) & 0x0000000000ff0000ULL) |
639
            ((x >> 40) & 0x000000000000ff00ULL) |
640
            ((x >> 56) & 0x00000000000000ffULL);
641
}
642
#endif
643

644
FORCE_INLINE U64 XXH_readLE64_align(const void* ptr, XXH_endianess endian, XXH_alignment align)
645
{
646
    if (align==XXH_unaligned)
647
        return endian==XXH_littleEndian ? XXH_read64(ptr) : XXH_swap64(XXH_read64(ptr));
648
    else
649
        return endian==XXH_littleEndian ? *(const U64*)ptr : XXH_swap64(*(const U64*)ptr);
650
}
651

652
FORCE_INLINE U64 XXH_readLE64(const void* ptr, XXH_endianess endian)
653
{
654
    return XXH_readLE64_align(ptr, endian, XXH_unaligned);
655
}
656

657
static U64 XXH_readBE64(const void* ptr)
658
{
659
    return XXH_CPU_LITTLE_ENDIAN ? XXH_swap64(XXH_read64(ptr)) : XXH_read64(ptr);
660
}
661

662

663
/*======   xxh64   ======*/
664

665
static const U64 PRIME64_1 = 11400714785074694791ULL;
666
static const U64 PRIME64_2 = 14029467366897019727ULL;
667
static const U64 PRIME64_3 =  1609587929392839161ULL;
668
static const U64 PRIME64_4 =  9650029242287828579ULL;
669
static const U64 PRIME64_5 =  2870177450012600261ULL;
670

671
static U64 XXH64_round(U64 acc, U64 input)
672
{
673
    acc += input * PRIME64_2;
674
    acc  = XXH_rotl64(acc, 31);
675
    acc *= PRIME64_1;
676
    return acc;
677
}
678

679
static U64 XXH64_mergeRound(U64 acc, U64 val)
680
{
681
    val  = XXH64_round(0, val);
682
    acc ^= val;
683
    acc  = acc * PRIME64_1 + PRIME64_4;
684
    return acc;
685
}
686

687
static U64 XXH64_avalanche(U64 h64)
688
{
689
    h64 ^= h64 >> 33;
690
    h64 *= PRIME64_2;
691
    h64 ^= h64 >> 29;
692
    h64 *= PRIME64_3;
693
    h64 ^= h64 >> 32;
694
    return h64;
695
}
696

697

698
#define XXH_get64bits(p) XXH_readLE64_align(p, endian, align)
699

700
static U64
701
XXH64_finalize(U64 h64, const void* ptr, size_t len,
702
               XXH_endianess endian, XXH_alignment align)
703
{
704
    const BYTE* p = (const BYTE*)ptr;
705

706
#define PROCESS1_64          \
707
    h64 ^= (*p) * PRIME64_5; \
708
    p++;                     \
709
    h64 = XXH_rotl64(h64, 11) * PRIME64_1;
710

711
#define PROCESS4_64          \
712
    h64 ^= (U64)(XXH_get32bits(p)) * PRIME64_1; \
713
    p+=4;                    \
714
    h64 = XXH_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
715

716
#define PROCESS8_64 {        \
717
    U64 const k1 = XXH64_round(0, XXH_get64bits(p)); \
718
    p+=8;                    \
719
    h64 ^= k1;               \
720
    h64  = XXH_rotl64(h64,27) * PRIME64_1 + PRIME64_4; \
721
}
722

723
    switch(len&31) {
724
      case 24: PROCESS8_64;
725
                    /* fallthrough */
726
      case 16: PROCESS8_64;
727
                    /* fallthrough */
728
      case  8: PROCESS8_64;
729
               return XXH64_avalanche(h64);
730

731
      case 28: PROCESS8_64;
732
                    /* fallthrough */
733
      case 20: PROCESS8_64;
734
                    /* fallthrough */
735
      case 12: PROCESS8_64;
736
                    /* fallthrough */
737
      case  4: PROCESS4_64;
738
               return XXH64_avalanche(h64);
739

740
      case 25: PROCESS8_64;
741
                    /* fallthrough */
742
      case 17: PROCESS8_64;
743
                    /* fallthrough */
744
      case  9: PROCESS8_64;
745
               PROCESS1_64;
746
               return XXH64_avalanche(h64);
747

748
      case 29: PROCESS8_64;
749
                    /* fallthrough */
750
      case 21: PROCESS8_64;
751
                    /* fallthrough */
752
      case 13: PROCESS8_64;
753
                    /* fallthrough */
754
      case  5: PROCESS4_64;
755
               PROCESS1_64;
756
               return XXH64_avalanche(h64);
757

758
      case 26: PROCESS8_64;
759
                    /* fallthrough */
760
      case 18: PROCESS8_64;
761
                    /* fallthrough */
762
      case 10: PROCESS8_64;
763
               PROCESS1_64;
764
               PROCESS1_64;
765
               return XXH64_avalanche(h64);
766

767
      case 30: PROCESS8_64;
768
                    /* fallthrough */
769
      case 22: PROCESS8_64;
770
                    /* fallthrough */
771
      case 14: PROCESS8_64;
772
                    /* fallthrough */
773
      case  6: PROCESS4_64;
774
               PROCESS1_64;
775
               PROCESS1_64;
776
               return XXH64_avalanche(h64);
777

778
      case 27: PROCESS8_64;
779
                    /* fallthrough */
780
      case 19: PROCESS8_64;
781
                    /* fallthrough */
782
      case 11: PROCESS8_64;
783
               PROCESS1_64;
784
               PROCESS1_64;
785
               PROCESS1_64;
786
               return XXH64_avalanche(h64);
787

788
      case 31: PROCESS8_64;
789
                    /* fallthrough */
790
      case 23: PROCESS8_64;
791
                    /* fallthrough */
792
      case 15: PROCESS8_64;
793
                    /* fallthrough */
794
      case  7: PROCESS4_64;
795
                    /* fallthrough */
796
      case  3: PROCESS1_64;
797
                    /* fallthrough */
798
      case  2: PROCESS1_64;
799
                    /* fallthrough */
800
      case  1: PROCESS1_64;
801
                    /* fallthrough */
802
      case  0: return XXH64_avalanche(h64);
803
    }
804

805
    /* impossible to reach */
806
    assert(0);
807
    return 0;  /* unreachable, but some compilers complain without it */
808
}
809

810
FORCE_INLINE U64
811
XXH64_endian_align(const void* input, size_t len, U64 seed,
812
                XXH_endianess endian, XXH_alignment align)
813
{
814
    const BYTE* p = (const BYTE*)input;
815
    const BYTE* bEnd = p + len;
816
    U64 h64;
817

818
#if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && (XXH_ACCEPT_NULL_INPUT_POINTER>=1)
819
    if (p==NULL) {
820
        len=0;
821
        bEnd=p=(const BYTE*)(size_t)32;
822
    }
823
#endif
824

825
    if (len>=32) {
826
        const BYTE* const limit = bEnd - 32;
827
        U64 v1 = seed + PRIME64_1 + PRIME64_2;
828
        U64 v2 = seed + PRIME64_2;
829
        U64 v3 = seed + 0;
830
        U64 v4 = seed - PRIME64_1;
831

832
        do {
833
            v1 = XXH64_round(v1, XXH_get64bits(p)); p+=8;
834
            v2 = XXH64_round(v2, XXH_get64bits(p)); p+=8;
835
            v3 = XXH64_round(v3, XXH_get64bits(p)); p+=8;
836
            v4 = XXH64_round(v4, XXH_get64bits(p)); p+=8;
837
        } while (p<=limit);
838

839
        h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);
840
        h64 = XXH64_mergeRound(h64, v1);
841
        h64 = XXH64_mergeRound(h64, v2);
842
        h64 = XXH64_mergeRound(h64, v3);
843
        h64 = XXH64_mergeRound(h64, v4);
844

845
    } else {
846
        h64  = seed + PRIME64_5;
847
    }
848

849
    h64 += (U64) len;
850

851
    return XXH64_finalize(h64, p, len, endian, align);
852
}
853

854

855
XXH_PUBLIC_API unsigned long long XXH64 (const void* input, size_t len, unsigned long long seed)
856
{
857
#if 0
858
    /* Simple version, good for code maintenance, but unfortunately slow for small inputs */
859
    XXH64_state_t state;
860
    XXH64_reset(&state, seed);
861
    XXH64_update(&state, input, len);
862
    return XXH64_digest(&state);
863
#else
864
    XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
865

866
    if (XXH_FORCE_ALIGN_CHECK) {
867
        if ((((size_t)input) & 7)==0) {  /* Input is aligned, let's leverage the speed advantage */
868
            if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
869
                return XXH64_endian_align(input, len, seed, XXH_littleEndian, XXH_aligned);
870
            else
871
                return XXH64_endian_align(input, len, seed, XXH_bigEndian, XXH_aligned);
872
    }   }
873

874
    if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
875
        return XXH64_endian_align(input, len, seed, XXH_littleEndian, XXH_unaligned);
876
    else
877
        return XXH64_endian_align(input, len, seed, XXH_bigEndian, XXH_unaligned);
878
#endif
879
}
880

881
/*======   Hash Streaming   ======*/
882

883
XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void)
884
{
885
    return (XXH64_state_t*)XXH_malloc(sizeof(XXH64_state_t));
886
}
887
XXH_PUBLIC_API XXH_errorcode XXH64_freeState(XXH64_state_t* statePtr)
888
{
889
    XXH_free(statePtr);
890
    return XXH_OK;
891
}
892

893
XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* dstState, const XXH64_state_t* srcState)
894
{
895
    memcpy(dstState, srcState, sizeof(*dstState));
896
}
897

898
XXH_PUBLIC_API XXH_errorcode XXH64_reset(XXH64_state_t* statePtr, unsigned long long seed)
899
{
900
    XXH64_state_t state;   /* using a local state to memcpy() in order to avoid strict-aliasing warnings */
901
    memset(&state, 0, sizeof(state));
902
    state.v1 = seed + PRIME64_1 + PRIME64_2;
903
    state.v2 = seed + PRIME64_2;
904
    state.v3 = seed + 0;
905
    state.v4 = seed - PRIME64_1;
906
     /* do not write into reserved, planned to be removed in a future version */
907
    memcpy(statePtr, &state, sizeof(state) - sizeof(state.reserved));
908
    return XXH_OK;
909
}
910

911
FORCE_INLINE
912
XXH_errorcode XXH64_update_endian (XXH64_state_t* state, const void* input, size_t len, XXH_endianess endian)
913
{
914
    const BYTE* p = (const BYTE*)input;
915
    const BYTE* const bEnd = p + len;
916

917
    if (input==NULL)
918
#if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && (XXH_ACCEPT_NULL_INPUT_POINTER>=1)
919
        return XXH_OK;
920
#else
921
        return XXH_ERROR;
922
#endif
923

924
    state->total_len += len;
925

926
    if (state->memsize + len < 32) {  /* fill in tmp buffer */
927
        XXH_memcpy(((BYTE*)state->mem64) + state->memsize, input, len);
928
        state->memsize += (U32)len;
929
        return XXH_OK;
930
    }
931

932
    if (state->memsize) {   /* tmp buffer is full */
933
        XXH_memcpy(((BYTE*)state->mem64) + state->memsize, input, 32-state->memsize);
934
        state->v1 = XXH64_round(state->v1, XXH_readLE64(state->mem64+0, endian));
935
        state->v2 = XXH64_round(state->v2, XXH_readLE64(state->mem64+1, endian));
936
        state->v3 = XXH64_round(state->v3, XXH_readLE64(state->mem64+2, endian));
937
        state->v4 = XXH64_round(state->v4, XXH_readLE64(state->mem64+3, endian));
938
        p += 32-state->memsize;
939
        state->memsize = 0;
940
    }
941

942
    if (p+32 <= bEnd) {
943
        const BYTE* const limit = bEnd - 32;
944
        U64 v1 = state->v1;
945
        U64 v2 = state->v2;
946
        U64 v3 = state->v3;
947
        U64 v4 = state->v4;
948

949
        do {
950
            v1 = XXH64_round(v1, XXH_readLE64(p, endian)); p+=8;
951
            v2 = XXH64_round(v2, XXH_readLE64(p, endian)); p+=8;
952
            v3 = XXH64_round(v3, XXH_readLE64(p, endian)); p+=8;
953
            v4 = XXH64_round(v4, XXH_readLE64(p, endian)); p+=8;
954
        } while (p<=limit);
955

956
        state->v1 = v1;
957
        state->v2 = v2;
958
        state->v3 = v3;
959
        state->v4 = v4;
960
    }
961

962
    if (p < bEnd) {
963
        XXH_memcpy(state->mem64, p, (size_t)(bEnd-p));
964
        state->memsize = (unsigned)(bEnd-p);
965
    }
966

967
    return XXH_OK;
968
}
969

970
XXH_PUBLIC_API XXH_errorcode XXH64_update (XXH64_state_t* state_in, const void* input, size_t len)
971
{
972
    XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
973

974
    if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
975
        return XXH64_update_endian(state_in, input, len, XXH_littleEndian);
976
    else
977
        return XXH64_update_endian(state_in, input, len, XXH_bigEndian);
978
}
979

980
FORCE_INLINE U64 XXH64_digest_endian (const XXH64_state_t* state, XXH_endianess endian)
981
{
982
    U64 h64;
983

984
    if (state->total_len >= 32) {
985
        U64 const v1 = state->v1;
986
        U64 const v2 = state->v2;
987
        U64 const v3 = state->v3;
988
        U64 const v4 = state->v4;
989

990
        h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);
991
        h64 = XXH64_mergeRound(h64, v1);
992
        h64 = XXH64_mergeRound(h64, v2);
993
        h64 = XXH64_mergeRound(h64, v3);
994
        h64 = XXH64_mergeRound(h64, v4);
995
    } else {
996
        h64  = state->v3 /*seed*/ + PRIME64_5;
997
    }
998

999
    h64 += (U64) state->total_len;
1000

1001
    return XXH64_finalize(h64, state->mem64, (size_t)state->total_len, endian, XXH_aligned);
1002
}
1003

1004
XXH_PUBLIC_API unsigned long long XXH64_digest (const XXH64_state_t* state_in)
1005
{
1006
    XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
1007

1008
    if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
1009
        return XXH64_digest_endian(state_in, XXH_littleEndian);
1010
    else
1011
        return XXH64_digest_endian(state_in, XXH_bigEndian);
1012
}
1013

1014

1015
/*====== Canonical representation   ======*/
1016

1017
XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash)
1018
{
1019
    XXH_STATIC_ASSERT(sizeof(XXH64_canonical_t) == sizeof(XXH64_hash_t));
1020
    if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap64(hash);
1021
    memcpy(dst, &hash, sizeof(*dst));
1022
}
1023

1024
XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src)
1025
{
1026
    return XXH_readBE64(src);
1027
}
1028

1029
#endif  /* XXH_NO_LONG_LONG */
1030