--- /dev/null
+/*
+ "Murmur" hash provided by Austin, tanjent@gmail.com
+ http://murmurhash.googlepages.com/
+
+ Note - This code makes a few assumptions about how your machine behaves -
+
+ 1. We can read a 4-byte value from any address without crashing
+ 2. sizeof(int) == 4
+
+ And it has a few limitations -
+ 1. It will not work incrementally.
+ 2. It will not produce the same results on little-endian and big-endian
+ machines.
+
+ Updated to murmur2 hash - BP
+*/
+
+#include <libhashkit/common.h>
+
+uint32_t hashkit_murmur(const char *key, size_t length, void *context)
+{
+ /*
+ 'm' and 'r' are mixing constants generated offline. They're not
+ really 'magic', they just happen to work well.
+ */
+
+ const unsigned int m= 0x5bd1e995;
+ const uint32_t seed= (0xdeadbeef * (uint32_t)length);
+ const int r= 24;
+
+
+ // Initialize the hash to a 'random' value
+
+ uint32_t h= seed ^ (uint32_t)length;
+
+ // Mix 4 bytes at a time into the hash
+
+ const unsigned char * data= (const unsigned char *)key;
+ (void)context;
+
+ while(length >= 4)
+ {
+ unsigned int k = *(unsigned int *)data;
+
+ k *= m;
+ k ^= k >> r;
+ k *= m;
+
+ h *= m;
+ h ^= k;
+
+ data += 4;
+ length -= 4;
+ }
+
+ // Handle the last few bytes of the input array
+
+ switch(length)
+ {
+ case 3: h ^= ((uint32_t)data[2]) << 16;
+ case 2: h ^= ((uint32_t)data[1]) << 8;
+ case 1: h ^= data[0];
+ h *= m;
+ default: break;
+ };
+
+ /*
+ 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;
+}