| #include "Platform.h" |
| #include <stdio.h> // for NULL |
| |
| /* By Paul Hsieh (C) 2004, 2005. Covered under the Paul Hsieh derivative |
| license. See: |
| http://www.azillionmonkeys.com/qed/weblicense.html for license details. |
| |
| http://www.azillionmonkeys.com/qed/hash.html */ |
| |
| /* |
| #undef get16bits |
| #if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__) \ |
| || defined(_MSC_VER) || defined (__BORLANDC__) || defined (__TURBOC__) |
| #define get16bits(d) (*((const uint16_t *) (d))) |
| #endif |
| |
| #if !defined (get16bits) |
| #define get16bits(d) ((((uint32_t)(((const uint8_t *)(d))[1])) << 8)\ |
| +(uint32_t)(((const uint8_t *)(d))[0]) ) |
| #endif |
| */ |
| |
| FORCE_INLINE uint16_t get16bits ( const void * p ) |
| { |
| return *(const uint16_t*)p; |
| } |
| |
| uint32_t SuperFastHash (const signed char * data, int len) { |
| uint32_t hash = 0, tmp; |
| int rem; |
| |
| if (len <= 0 || data == NULL) return 0; |
| |
| rem = len & 3; |
| len >>= 2; |
| |
| /* Main loop */ |
| for (;len > 0; len--) { |
| hash += get16bits (data); |
| tmp = (get16bits (data+2) << 11) ^ hash; |
| hash = (hash << 16) ^ tmp; |
| data += 2*sizeof (uint16_t); |
| hash += hash >> 11; |
| } |
| |
| /* Handle end cases */ |
| switch (rem) { |
| case 3: hash += get16bits (data); |
| hash ^= hash << 16; |
| hash ^= data[sizeof (uint16_t)] << 18; |
| hash += hash >> 11; |
| break; |
| case 2: hash += get16bits (data); |
| hash ^= hash << 11; |
| hash += hash >> 17; |
| break; |
| case 1: hash += *data; |
| hash ^= hash << 10; |
| hash += hash >> 1; |
| } |
| |
| /* Force "avalanching" of final 127 bits */ |
| hash ^= hash << 3; |
| hash += hash >> 5; |
| hash ^= hash << 4; |
| hash += hash >> 17; |
| hash ^= hash << 25; |
| hash += hash >> 6; |
| |
| return hash; |
| } |
| |
| void SuperFastHash ( const void * key, int len, uint32_t /*seed*/, void * out ) |
| { |
| *(uint32_t*)out = SuperFastHash((const signed char*)key,len); |
| } |