xref: /third_party/lz4/lib/xxhash.c (revision 27b27ec6)
1/*
2*  xxHash - Fast Hash algorithm
3*  Copyright (C) 2012-2016, Yann Collet
4*
5*  BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
6*
7*  Redistribution and use in source and binary forms, with or without
8*  modification, are permitted provided that the following conditions are
9*  met:
10*
11*  * Redistributions of source code must retain the above copyright
12*  notice, this list of conditions and the following disclaimer.
13*  * Redistributions in binary form must reproduce the above
14*  copyright notice, this list of conditions and the following disclaimer
15*  in the documentation and/or other materials provided with the
16*  distribution.
17*
18*  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19*  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20*  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21*  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22*  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23*  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24*  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25*  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26*  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27*  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28*  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29*
30*  You can contact the author at :
31*  - xxHash homepage: http://www.xxhash.com
32*  - xxHash source repository : https://github.com/Cyan4973/xxHash
33*/
34
35
36/* *************************************
37*  Tuning parameters
38***************************************/
39/*!XXH_FORCE_MEMORY_ACCESS :
40 * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
41 * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
42 * The below switch allow to select different access method for improved performance.
43 * Method 0 (default) : use `memcpy()`. Safe and portable.
44 * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
45 *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
46 * Method 2 : direct access. This method doesn't depend on compiler but violate C standard.
47 *            It can generate buggy code on targets which do not support unaligned memory accesses.
48 *            But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
49 * See http://stackoverflow.com/a/32095106/646947 for details.
50 * Prefer these methods in priority order (0 > 1 > 2)
51 */
52#ifndef XXH_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
53#  if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) \
54                        || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) \
55                        || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
56#    define XXH_FORCE_MEMORY_ACCESS 2
57#  elif (defined(__INTEL_COMPILER) && !defined(_WIN32)) || \
58  (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) \
59                    || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) \
60                    || defined(__ARM_ARCH_7S__) ))
61#    define XXH_FORCE_MEMORY_ACCESS 1
62#  endif
63#endif
64
65/*!XXH_ACCEPT_NULL_INPUT_POINTER :
66 * If input pointer is NULL, xxHash default behavior is to dereference it, triggering a segfault.
67 * When this macro is enabled, xxHash actively checks input for null pointer.
68 * It it is, result for null input pointers is the same as a null-length input.
69 */
70#ifndef XXH_ACCEPT_NULL_INPUT_POINTER   /* can be defined externally */
71#  define XXH_ACCEPT_NULL_INPUT_POINTER 0
72#endif
73
74/*!XXH_FORCE_NATIVE_FORMAT :
75 * 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.
78 * Should endian-independence be of no importance for your application, you may set the #define below to 1,
79 * 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 */
83#  define XXH_FORCE_NATIVE_FORMAT 0
84#endif
85
86/*!XXH_FORCE_ALIGN_CHECK :
87 * This is a minor performance trick, only useful with lots of very small keys.
88 * It means : check for aligned/unaligned input.
89 * The check costs one initial branch per hash;
90 * set it to 0 when the input is guaranteed to be aligned,
91 * or when alignment doesn't matter for performance.
92 */
93#ifndef XXH_FORCE_ALIGN_CHECK /* can be defined externally */
94#  if defined(__i386) || defined(_M_IX86) || defined(__x86_64__) || defined(_M_X64)
95#    define XXH_FORCE_ALIGN_CHECK 0
96#  else
97#    define XXH_FORCE_ALIGN_CHECK 1
98#  endif
99#endif
100
101
102/* *************************************
103*  Includes & Memory related functions
104***************************************/
105/*! Modify the local functions below should you wish to use some other memory routines
106*   for malloc(), free() */
107#include <stdlib.h>
108static void* XXH_malloc(size_t s) { return malloc(s); }
109static void  XXH_free  (void* p)  { free(p); }
110/*! and for memcpy() */
111#include <string.h>
112static void* XXH_memcpy(void* dest, const void* src, size_t size) { return memcpy(dest,src,size); }
113
114#include <assert.h>   /* assert */
115
116#define XXH_STATIC_LINKING_ONLY
117#include "xxhash.h"
118
119
120/* *************************************
121*  Compiler Specific Options
122***************************************/
123#ifdef _MSC_VER    /* Visual Studio */
124#  pragma warning(disable : 4127)      /* disable: C4127: conditional expression is constant */
125#  define FORCE_INLINE static __forceinline
126#else
127#  if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
128#    ifdef __GNUC__
129#      define FORCE_INLINE static inline __attribute__((always_inline))
130#    else
131#      define FORCE_INLINE static inline
132#    endif
133#  else
134#    define FORCE_INLINE static
135#  endif /* __STDC_VERSION__ */
136#endif
137
138
139/* *************************************
140*  Basic Types
141***************************************/
142#ifndef MEM_MODULE
143# if !defined (__VMS) \
144  && (defined (__cplusplus) \
145  || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
146#   include <stdint.h>
147    typedef uint8_t  BYTE;
148    typedef uint16_t U16;
149    typedef uint32_t U32;
150# else
151    typedef unsigned char      BYTE;
152    typedef unsigned short     U16;
153    typedef unsigned int       U32;
154# 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 */
160static 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 */
166typedef union { U32 u32; } __attribute__((packed)) unalign;
167static 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 */
174static 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
186******************************************/
187#define XXH_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)))
195#  define XXH_rotl64(x,r) ((x << r) | (x >> (64 - r)))
196#endif
197
198#if defined(_MSC_VER)     /* Visual Studio */
199#  define XXH_swap32 _byteswap_ulong
200#elif XXH_GCC_VERSION >= 403
201#  define XXH_swap32 __builtin_bswap32
202#else
203static U32 XXH_swap32 (U32 x)
204{
205    return  ((x << 24) & 0xff000000 ) |
206            ((x <<  8) & 0x00ff0000 ) |
207            ((x >>  8) & 0x0000ff00 ) |
208            ((x >> 24) & 0x000000ff );
209}
210#endif
211
212
213/* *************************************
214*  Architecture Macros
215***************************************/
216typedef 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
220static 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()
226#endif
227
228
229/* ***************************
230*  Memory reads
231*****************************/
232typedef enum { XXH_aligned, XXH_unaligned } XXH_alignment;
233
234FORCE_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
242FORCE_INLINE U32 XXH_readLE32(const void* ptr, XXH_endianess endian)
243{
244    return XXH_readLE32_align(ptr, endian, XXH_unaligned);
245}
246
247static 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
255***************************************/
256#define XXH_STATIC_ASSERT(c)  { enum { XXH_sa = 1/(int)(!!(c)) }; }  /* use after variable declarations */
257XXH_PUBLIC_API unsigned XXH_versionNumber (void) { return XXH_VERSION_NUMBER; }
258
259
260/* *******************************************************************
261*  32-bit hash functions
262*********************************************************************/
263static const U32 PRIME32_1 = 2654435761U;
264static const U32 PRIME32_2 = 2246822519U;
265static const U32 PRIME32_3 = 3266489917U;
266static const U32 PRIME32_4 =  668265263U;
267static const U32 PRIME32_5 =  374761393U;
268
269static 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 */
278static 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
290static U32
291XXH32_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
297#define PROCESS1               \
298    h32 += (*p++) * PRIME32_5; \
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
351FORCE_INLINE U32
352XXH32_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
392XXH_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
422XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void)
423{
424    return (XXH32_state_t*)XXH_malloc(sizeof(XXH32_state_t));
425}
426XXH_PUBLIC_API XXH_errorcode XXH32_freeState(XXH32_state_t* statePtr)
427{
428    XXH_free(statePtr);
429    return XXH_OK;
430}
431
432XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* dstState, const XXH32_state_t* srcState)
433{
434    memcpy(dstState, srcState, sizeof(*dstState));
435}
436
437XXH_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
451FORCE_INLINE XXH_errorcode
452XXH32_update_endian(XXH32_state_t* state, const void* input, size_t len, XXH_endianess endian)
453{
454    if (input==NULL)
455#if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && (XXH_ACCEPT_NULL_INPUT_POINTER>=1)
456        return XXH_OK;
457#else
458        return XXH_ERROR;
459#endif
460
461    {   const BYTE* p = (const BYTE*)input;
462        const BYTE* const bEnd = p + len;
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
511    return XXH_OK;
512}
513
514
515XXH_PUBLIC_API XXH_errorcode XXH32_update (XXH32_state_t* state_in, const void* input, size_t len)
516{
517    XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
518
519    if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
520        return XXH32_update_endian(state_in, input, len, XXH_littleEndian);
521    else
522        return XXH32_update_endian(state_in, input, len, XXH_bigEndian);
523}
524
525
526FORCE_INLINE U32
527XXH32_digest_endian (const XXH32_state_t* state, XXH_endianess endian)
528{
529    U32 h32;
530
531    if (state->large_len) {
532        h32 = XXH_rotl32(state->v1, 1)
533            + XXH_rotl32(state->v2, 7)
534            + XXH_rotl32(state->v3, 12)
535            + XXH_rotl32(state->v4, 18);
536    } else {
537        h32 = state->v3 /* == seed */ + PRIME32_5;
538    }
539
540    h32 += state->total_len_32;
541
542    return XXH32_finalize(h32, state->mem32, state->memsize, endian, XXH_aligned);
543}
544
545
546XXH_PUBLIC_API unsigned int XXH32_digest (const XXH32_state_t* state_in)
547{
548    XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
549
550    if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
551        return XXH32_digest_endian(state_in, XXH_littleEndian);
552    else
553        return XXH32_digest_endian(state_in, XXH_bigEndian);
554}
555
556
557/*======   Canonical representation   ======*/
558
559/*! Default XXH result types are basic unsigned 32 and 64 bits.
560*   The canonical representation follows human-readable write convention, aka big-endian (large digits first).
561*   These functions allow transformation of hash result into and from its canonical format.
562*   This way, hash values can be written into a file or buffer, remaining comparable across different systems.
563*/
564
565XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash)
566{
567    XXH_STATIC_ASSERT(sizeof(XXH32_canonical_t) == sizeof(XXH32_hash_t));
568    if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap32(hash);
569    memcpy(dst, &hash, sizeof(*dst));
570}
571
572XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src)
573{
574    return XXH_readBE32(src);
575}
576
577
578#ifndef XXH_NO_LONG_LONG
579
580/* *******************************************************************
581*  64-bit hash functions
582*********************************************************************/
583
584/*======   Memory access   ======*/
585
586#ifndef MEM_MODULE
587# define MEM_MODULE
588# if !defined (__VMS) \
589  && (defined (__cplusplus) \
590  || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
591#   include <stdint.h>
592    typedef uint64_t U64;
593# else
594    /* if compiler doesn't support unsigned long long, replace by another 64-bit type */
595    typedef unsigned long long U64;
596# endif
597#endif
598
599
600#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))
601
602/* Force direct memory access. Only works on CPU which support unaligned memory access in hardware */
603static U64 XXH_read64(const void* memPtr) { return *(const U64*) memPtr; }
604
605#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))
606
607/* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
608/* currently only defined for gcc and icc */
609typedef union { U32 u32; U64 u64; } __attribute__((packed)) unalign64;
610static U64 XXH_read64(const void* ptr) { return ((const unalign64*)ptr)->u64; }
611
612#else
613
614/* portable and safe solution. Generally efficient.
615 * see : http://stackoverflow.com/a/32095106/646947
616 */
617
618static U64 XXH_read64(const void* memPtr)
619{
620    U64 val;
621    memcpy(&val, memPtr, sizeof(val));
622    return val;
623}
624
625#endif   /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
626
627#if defined(_MSC_VER)     /* Visual Studio */
628#  define XXH_swap64 _byteswap_uint64
629#elif XXH_GCC_VERSION >= 403
630#  define XXH_swap64 __builtin_bswap64
631#else
632static U64 XXH_swap64 (U64 x)
633{
634    return  ((x << 56) & 0xff00000000000000ULL) |
635            ((x << 40) & 0x00ff000000000000ULL) |
636            ((x << 24) & 0x0000ff0000000000ULL) |
637            ((x << 8)  & 0x000000ff00000000ULL) |
638            ((x >> 8)  & 0x00000000ff000000ULL) |
639            ((x >> 24) & 0x0000000000ff0000ULL) |
640            ((x >> 40) & 0x000000000000ff00ULL) |
641            ((x >> 56) & 0x00000000000000ffULL);
642}
643#endif
644
645FORCE_INLINE U64 XXH_readLE64_align(const void* ptr, XXH_endianess endian, XXH_alignment align)
646{
647    if (align==XXH_unaligned)
648        return endian==XXH_littleEndian ? XXH_read64(ptr) : XXH_swap64(XXH_read64(ptr));
649    else
650        return endian==XXH_littleEndian ? *(const U64*)ptr : XXH_swap64(*(const U64*)ptr);
651}
652
653FORCE_INLINE U64 XXH_readLE64(const void* ptr, XXH_endianess endian)
654{
655    return XXH_readLE64_align(ptr, endian, XXH_unaligned);
656}
657
658static U64 XXH_readBE64(const void* ptr)
659{
660    return XXH_CPU_LITTLE_ENDIAN ? XXH_swap64(XXH_read64(ptr)) : XXH_read64(ptr);
661}
662
663
664/*======   xxh64   ======*/
665
666static const U64 PRIME64_1 = 11400714785074694791ULL;
667static const U64 PRIME64_2 = 14029467366897019727ULL;
668static const U64 PRIME64_3 =  1609587929392839161ULL;
669static const U64 PRIME64_4 =  9650029242287828579ULL;
670static const U64 PRIME64_5 =  2870177450012600261ULL;
671
672static U64 XXH64_round(U64 acc, U64 input)
673{
674    acc += input * PRIME64_2;
675    acc  = XXH_rotl64(acc, 31);
676    acc *= PRIME64_1;
677    return acc;
678}
679
680static U64 XXH64_mergeRound(U64 acc, U64 val)
681{
682    val  = XXH64_round(0, val);
683    acc ^= val;
684    acc  = acc * PRIME64_1 + PRIME64_4;
685    return acc;
686}
687
688static U64 XXH64_avalanche(U64 h64)
689{
690    h64 ^= h64 >> 33;
691    h64 *= PRIME64_2;
692    h64 ^= h64 >> 29;
693    h64 *= PRIME64_3;
694    h64 ^= h64 >> 32;
695    return h64;
696}
697
698
699#define XXH_get64bits(p) XXH_readLE64_align(p, endian, align)
700
701static U64
702XXH64_finalize(U64 h64, const void* ptr, size_t len,
703               XXH_endianess endian, XXH_alignment align)
704{
705    const BYTE* p = (const BYTE*)ptr;
706
707#define PROCESS1_64            \
708    h64 ^= (*p++) * PRIME64_5; \
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
810FORCE_INLINE U64
811XXH64_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
855XXH_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
883XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void)
884{
885    return (XXH64_state_t*)XXH_malloc(sizeof(XXH64_state_t));
886}
887XXH_PUBLIC_API XXH_errorcode XXH64_freeState(XXH64_state_t* statePtr)
888{
889    XXH_free(statePtr);
890    return XXH_OK;
891}
892
893XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* dstState, const XXH64_state_t* srcState)
894{
895    memcpy(dstState, srcState, sizeof(*dstState));
896}
897
898XXH_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
911FORCE_INLINE XXH_errorcode
912XXH64_update_endian (XXH64_state_t* state, const void* input, size_t len, XXH_endianess endian)
913{
914    if (input==NULL)
915#if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && (XXH_ACCEPT_NULL_INPUT_POINTER>=1)
916        return XXH_OK;
917#else
918        return XXH_ERROR;
919#endif
920
921    {   const BYTE* p = (const BYTE*)input;
922        const BYTE* const bEnd = p + len;
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
968    return XXH_OK;
969}
970
971XXH_PUBLIC_API XXH_errorcode XXH64_update (XXH64_state_t* state_in, const void* input, size_t len)
972{
973    XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
974
975    if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
976        return XXH64_update_endian(state_in, input, len, XXH_littleEndian);
977    else
978        return XXH64_update_endian(state_in, input, len, XXH_bigEndian);
979}
980
981FORCE_INLINE U64 XXH64_digest_endian (const XXH64_state_t* state, XXH_endianess endian)
982{
983    U64 h64;
984
985    if (state->total_len >= 32) {
986        U64 const v1 = state->v1;
987        U64 const v2 = state->v2;
988        U64 const v3 = state->v3;
989        U64 const v4 = state->v4;
990
991        h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);
992        h64 = XXH64_mergeRound(h64, v1);
993        h64 = XXH64_mergeRound(h64, v2);
994        h64 = XXH64_mergeRound(h64, v3);
995        h64 = XXH64_mergeRound(h64, v4);
996    } else {
997        h64  = state->v3 /*seed*/ + PRIME64_5;
998    }
999
1000    h64 += (U64) state->total_len;
1001
1002    return XXH64_finalize(h64, state->mem64, (size_t)state->total_len, endian, XXH_aligned);
1003}
1004
1005XXH_PUBLIC_API unsigned long long XXH64_digest (const XXH64_state_t* state_in)
1006{
1007    XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
1008
1009    if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
1010        return XXH64_digest_endian(state_in, XXH_littleEndian);
1011    else
1012        return XXH64_digest_endian(state_in, XXH_bigEndian);
1013}
1014
1015
1016/*====== Canonical representation   ======*/
1017
1018XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash)
1019{
1020    XXH_STATIC_ASSERT(sizeof(XXH64_canonical_t) == sizeof(XXH64_hash_t));
1021    if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap64(hash);
1022    memcpy(dst, &hash, sizeof(*dst));
1023}
1024
1025XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src)
1026{
1027    return XXH_readBE64(src);
1028}
1029
1030#endif  /* XXH_NO_LONG_LONG */
1031