tanjent@gmail.com | f3b7897 | 2012-03-01 03:38:55 +0000 | [diff] [blame] | 1 | #include "Hashes.h" |
| 2 | |
| 3 | #include "Random.h" |
| 4 | |
| 5 | |
| 6 | #include <stdlib.h> |
| 7 | //#include <stdint.h> |
| 8 | #include <assert.h> |
| 9 | //#include <emmintrin.h> |
| 10 | //#include <xmmintrin.h> |
| 11 | |
| 12 | //---------------------------------------------------------------------------- |
| 13 | // fake / bad hashes |
| 14 | |
| 15 | void BadHash ( const void * key, int len, uint32_t seed, void * out ) |
| 16 | { |
| 17 | uint32_t h = seed; |
| 18 | |
| 19 | const uint8_t * data = (const uint8_t*)key; |
| 20 | |
| 21 | for(int i = 0; i < len; i++) |
| 22 | { |
| 23 | h ^= h >> 3; |
| 24 | h ^= h << 5; |
| 25 | h ^= data[i]; |
| 26 | } |
| 27 | |
| 28 | *(uint32_t*)out = h; |
| 29 | } |
| 30 | |
| 31 | void sumhash ( const void * key, int len, uint32_t seed, void * out ) |
| 32 | { |
| 33 | uint32_t h = seed; |
| 34 | |
| 35 | const uint8_t * data = (const uint8_t*)key; |
| 36 | |
| 37 | for(int i = 0; i < len; i++) |
| 38 | { |
| 39 | h += data[i]; |
| 40 | } |
| 41 | |
| 42 | *(uint32_t*)out = h; |
| 43 | } |
| 44 | |
| 45 | void sumhash32 ( const void * key, int len, uint32_t seed, void * out ) |
| 46 | { |
| 47 | uint32_t h = seed; |
| 48 | |
| 49 | const uint32_t * data = (const uint32_t*)key; |
| 50 | |
| 51 | for(int i = 0; i < len/4; i++) |
| 52 | { |
| 53 | h += data[i]; |
| 54 | } |
| 55 | |
| 56 | *(uint32_t*)out = h; |
| 57 | } |
| 58 | |
| 59 | void DoNothingHash ( const void *, int, uint32_t, void * ) |
| 60 | { |
| 61 | } |
| 62 | |
| 63 | //----------------------------------------------------------------------------- |
| 64 | // One-byte-at-a-time hash based on Murmur's mix |
| 65 | |
| 66 | uint32_t MurmurOAAT ( const void * key, int len, uint32_t seed ) |
| 67 | { |
| 68 | const uint8_t * data = (const uint8_t*)key; |
| 69 | |
| 70 | uint32_t h = seed; |
| 71 | |
| 72 | for(int i = 0; i < len; i++) |
| 73 | { |
| 74 | h ^= data[i]; |
| 75 | h *= 0x5bd1e995; |
| 76 | h ^= h >> 15; |
| 77 | } |
| 78 | |
| 79 | return h; |
| 80 | } |
| 81 | |
| 82 | void MurmurOAAT_test ( const void * key, int len, uint32_t seed, void * out ) |
| 83 | { |
| 84 | *(uint32_t*)out = MurmurOAAT(key,len,seed); |
| 85 | } |
| 86 | |
| 87 | //---------------------------------------------------------------------------- |
| 88 | |
| 89 | void FNV ( const void * key, int len, uint32_t seed, void * out ) |
| 90 | { |
| 91 | unsigned int h = seed; |
| 92 | |
| 93 | const uint8_t * data = (const uint8_t*)key; |
| 94 | |
| 95 | h ^= BIG_CONSTANT(2166136261); |
| 96 | |
| 97 | for(int i = 0; i < len; i++) |
| 98 | { |
| 99 | h ^= data[i]; |
| 100 | h *= 16777619; |
| 101 | } |
| 102 | |
| 103 | *(uint32_t*)out = h; |
| 104 | } |
| 105 | |
| 106 | //----------------------------------------------------------------------------- |
| 107 | |
| 108 | uint32_t x17 ( const void * key, int len, uint32_t h ) |
| 109 | { |
| 110 | const uint8_t * data = (const uint8_t*)key; |
| 111 | |
| 112 | for(int i = 0; i < len; ++i) |
| 113 | { |
| 114 | h = 17 * h + (data[i] - ' '); |
| 115 | } |
| 116 | |
| 117 | return h ^ (h >> 16); |
| 118 | } |
| 119 | |
| 120 | //----------------------------------------------------------------------------- |
| 121 | |
| 122 | void Bernstein ( const void * key, int len, uint32_t seed, void * out ) |
| 123 | { |
| 124 | const uint8_t * data = (const uint8_t*)key; |
| 125 | |
| 126 | for(int i = 0; i < len; ++i) |
| 127 | { |
| 128 | seed = 33 * seed + data[i]; |
| 129 | } |
| 130 | |
| 131 | *(uint32_t*)out = seed; |
| 132 | } |
| 133 | |
| 134 | //----------------------------------------------------------------------------- |
| 135 | // Crap8 hash from http://www.team5150.com/~andrew/noncryptohashzoo/Crap8.html |
| 136 | |
| 137 | uint32_t Crap8( const uint8_t *key, uint32_t len, uint32_t seed ) { |
| 138 | #define c8fold( a, b, y, z ) { p = (uint32_t)(a) * (uint64_t)(b); y ^= (uint32_t)p; z ^= (uint32_t)(p >> 32); } |
| 139 | #define c8mix( in ) { h *= m; c8fold( in, m, k, h ); } |
| 140 | |
| 141 | const uint32_t m = 0x83d2e73b, n = 0x97e1cc59, *key4 = (const uint32_t *)key; |
| 142 | uint32_t h = len + seed, k = n + len; |
| 143 | uint64_t p; |
| 144 | |
| 145 | while ( len >= 8 ) { c8mix(key4[0]) c8mix(key4[1]) key4 += 2; len -= 8; } |
| 146 | if ( len >= 4 ) { c8mix(key4[0]) key4 += 1; len -= 4; } |
| 147 | if ( len ) { c8mix( key4[0] & ( ( 1 << ( len * 8 ) ) - 1 ) ) } |
| 148 | c8fold( h ^ k, n, k, k ) |
| 149 | return k; |
| 150 | } |
| 151 | |
| 152 | void Crap8_test ( const void * key, int len, uint32_t seed, void * out ) |
| 153 | { |
| 154 | *(uint32_t*)out = Crap8((const uint8_t*)key,len,seed); |
| 155 | } |