1 files changed, 46 insertions, 0 deletions
diff --git a/util/hash.c b/util/hash.c
new file mode 100644
index 0000000..5f9b482
--- /dev/null
+++ b/util/hash.c
@@ -0,0 +1,46 @@
+#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;
+} 
+
+