#include "hash.h"

uint64_t murmur_hash_64a(void const * key, int len, unsigned int seed)
{
	const uint64_t m = 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 = *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;
}