Initial import of libucore

src/ucore_murmurhash.c

@@ -0,0 +1,55 @@
+#include "ucore_hash.h"
+
+// 'm' and 'r' are mixing constants generated offline.
+// They're not really 'magic', they just happen to work well.
+#define m  0x5bd1e995
+#define r  24
+
+uint32_t 
+uc_murmurmash2(const void *key, int len, uint32_t seed )
+{
+
+
+    // Initialize the hash to a 'random' value
+
+    uint32_t h = seed ^ len;
+
+    // Mix 4 bytes at a time into the hash
+
+    const unsigned char * data = (const unsigned char *)key;
+
+    while(len >= 4)
+    {
+        uint32_t k = *(uint32_t *)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;
+} 
+