MurmurHash2

unsigned int murMurHash(const void *key, int len)
{
const unsigned int m = 0x5bd1e995;
const int r = 24;
const int seed = 97;
unsigned int h = seed ^ len;
// Mix 4 bytes at a time into the hash
const unsigned char *data = (const unsigned char *)key;
while(len >= 4)
{
unsigned int k = *(unsigned int *)data;
k *= m;
k ^= k >> r;
k *= m;
h *= m;
h ^= k;
data += 4;
len -= 4;
}
// Handle the last few bytes of the input array
switch(len)
{
case 3: h ^= data[2] << 16;
case 2: h ^= data[1] << 8;
case 1: h ^= data[0];
h *= m;
};
// Do a few final mixes of the hash to ensure the last few
// bytes are well-incorporated.
h ^= h >> 13;
h *= m;
h ^= h >> 15;
return h;
}

猜你喜欢

转载自www.cnblogs.com/mu-zhang/p/11509020.html