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#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);
}
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