diff options
Diffstat (limited to 'src/ck_ht_hash.h')
-rw-r--r-- | src/ck_ht_hash.h | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/src/ck_ht_hash.h b/src/ck_ht_hash.h new file mode 100644 index 0000000..cd3d7a5 --- /dev/null +++ b/src/ck_ht_hash.h @@ -0,0 +1,269 @@ +/* + * Copyright 2012-2015 Samy Al Bahra + * Copyright 2011-2014 AppNexus, Inc. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. 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 AUTHOR 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 AUTHOR 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. + */ + +#ifndef CK_HT_HASH_H +#define CK_HT_HASH_H + +/* + * This is the Murmur hash written by Austin Appleby. + */ + +#include <ck_stdint.h> +#include <ck_string.h> + +//----------------------------------------------------------------------------- +// MurmurHash3 was written by Austin Appleby, and is placed in the public +// domain. The author hereby disclaims copyright to this source code. + +// Note - The x86 and x64 versions do _not_ produce the same results, as the +// algorithms are optimized for their respective platforms. You can still +// compile and run any of them on any platform, but your performance with the +// non-native version will be less than optimal. + +//----------------------------------------------------------------------------- +// Platform-specific functions and macros + +// Microsoft Visual Studio + +#if defined(_MSC_VER) + +#define FORCE_INLINE __forceinline + +#include <stdlib.h> + +#define ROTL32(x,y) _rotl(x,y) +#define ROTL64(x,y) _rotl64(x,y) + +#define BIG_CONSTANT(x) (x) + +// Other compilers + +#else // defined(_MSC_VER) + +#define FORCE_INLINE inline __attribute__((always_inline)) + +static inline uint32_t rotl32 ( uint32_t x, int8_t r ) +{ + return (x << r) | (x >> (32 - r)); +} + +static inline uint64_t rotl64 ( uint64_t x, int8_t r ) +{ + return (x << r) | (x >> (64 - r)); +} + +#define ROTL32(x,y) rotl32(x,y) +#define ROTL64(x,y) rotl64(x,y) + +#define BIG_CONSTANT(x) (x##LLU) + +#endif // !defined(_MSC_VER) + +//----------------------------------------------------------------------------- +// Block read - if your platform needs to do endian-swapping or can only +// handle aligned reads, do the conversion here + +FORCE_INLINE static uint32_t getblock ( const uint32_t * p, int i ) +{ + return p[i]; +} + +//----------------------------------------------------------------------------- +// Finalization mix - force all bits of a hash block to avalanche + +FORCE_INLINE static uint32_t fmix ( uint32_t h ) +{ + h ^= h >> 16; + h *= 0x85ebca6b; + h ^= h >> 13; + h *= 0xc2b2ae35; + h ^= h >> 16; + + return h; +} + +//----------------------------------------------------------------------------- + +static inline void MurmurHash3_x86_32 ( const void * key, int len, + uint32_t seed, uint32_t * out ) +{ + const uint8_t * data = (const uint8_t*)key; + const int nblocks = len / 4; + int i; + + uint32_t h1 = seed; + + uint32_t c1 = 0xcc9e2d51; + uint32_t c2 = 0x1b873593; + + //---------- + // body + + const uint32_t * blocks = (const uint32_t *)(const void *)(data + nblocks*4); + + for(i = -nblocks; i; i++) + { + uint32_t k1 = getblock(blocks,i); + + k1 *= c1; + k1 = ROTL32(k1,15); + k1 *= c2; + + h1 ^= k1; + h1 = ROTL32(h1,13); + h1 = h1*5+0xe6546b64; + } + + //---------- + // tail + + const uint8_t * tail = (const uint8_t*)(data + nblocks*4); + + uint32_t k1 = 0; + + switch(len & 3) + { + case 3: k1 ^= tail[2] << 16; + case 2: k1 ^= tail[1] << 8; + case 1: k1 ^= tail[0]; + k1 *= c1; k1 = ROTL32(k1,15); k1 *= c2; h1 ^= k1; + }; + + //---------- + // finalization + + h1 ^= len; + + h1 = fmix(h1); + + *(uint32_t *)out = h1; +} + +static inline uint64_t MurmurHash64A ( const void * key, int len, uint64_t seed ) +{ + const uint64_t m = BIG_CONSTANT(0xc6a4a7935bd1e995); + const int r = 47; + + uint64_t h = seed ^ (len * m); + + const uint64_t * data = (const uint64_t *)key; + const uint64_t * end = data + (len/8); + + while(data != end) + { + uint64_t k; + + if (!((uintptr_t)data & 0x7)) + k = *data++; + else { + memcpy(&k, data, sizeof(k)); + data++; + } + + k *= m; + k ^= k >> r; + k *= m; + + h ^= k; + h *= m; + } + + const unsigned char * data2 = (const unsigned char*)data; + + switch(len & 7) + { + case 7: h ^= (uint64_t)(data2[6]) << 48; + case 6: h ^= (uint64_t)(data2[5]) << 40; + case 5: h ^= (uint64_t)(data2[4]) << 32; + case 4: h ^= (uint64_t)(data2[3]) << 24; + case 3: h ^= (uint64_t)(data2[2]) << 16; + case 2: h ^= (uint64_t)(data2[1]) << 8; + case 1: h ^= (uint64_t)(data2[0]); + h *= m; + }; + + h ^= h >> r; + h *= m; + h ^= h >> r; + + return h; +} + + +// 64-bit hash for 32-bit platforms + +static inline uint64_t MurmurHash64B ( const void * key, int len, uint64_t seed ) +{ + const uint32_t m = 0x5bd1e995; + const int r = 24; + + uint32_t h1 = (uint32_t)(seed) ^ len; + uint32_t h2 = (uint32_t)(seed >> 32); + + const uint32_t * data = (const uint32_t *)key; + + while(len >= 8) + { + uint32_t k1 = *data++; + k1 *= m; k1 ^= k1 >> r; k1 *= m; + h1 *= m; h1 ^= k1; + len -= 4; + + uint32_t k2 = *data++; + k2 *= m; k2 ^= k2 >> r; k2 *= m; + h2 *= m; h2 ^= k2; + len -= 4; + } + + if(len >= 4) + { + uint32_t k1 = *data++; + k1 *= m; k1 ^= k1 >> r; k1 *= m; + h1 *= m; h1 ^= k1; + len -= 4; + } + + switch(len) + { + case 3: h2 ^= ((const unsigned char*)data)[2] << 16; + case 2: h2 ^= ((const unsigned char*)data)[1] << 8; + case 1: h2 ^= ((const unsigned char*)data)[0]; + h2 *= m; + }; + + h1 ^= h2 >> 18; h1 *= m; + h2 ^= h1 >> 22; h2 *= m; + h1 ^= h2 >> 17; h1 *= m; + h2 ^= h1 >> 19; h2 *= m; + + uint64_t h = h1; + + h = (h << 32) | h2; + + return h; +} + +#endif /* CK_HT_HASH_H */ |