X-Git-Url: https://pd.if.org/git/?p=nbds;a=blobdiff_plain;f=include%2Fmurmur.h;h=62e26dcd1e0952b861b0e8eca5d9d0409cfa456b;hp=fcb4cb642a9f08285d968135ca67f59712270e8e;hb=2cce67f0002cdb6dcdc2ab8ccf837e3d2b3336de;hpb=4a7804bd08c790fc3c4233312e4b485c3302fe02

diff --git a/include/murmur.h b/include/murmur.h
index fcb4cb6..62e26dc 100644
--- a/include/murmur.h
+++ b/include/murmur.h
@@ -61,3 +61,44 @@ static inline unsigned int murmur32 (const char *key, int len)
 
 	return h;
 } 
+
+static inline unsigned int murmur32_8b (uint64_t key)
+{
+    // '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 int r = 24;
+
+    // Initialize the hash to a 'random' value
+    unsigned int h = 8;
+
+    const unsigned char *data = (const unsigned char *)&key;
+
+    uint32_t k1 = *(uint32_t *)data;
+    uint32_t k2 = *(uint32_t *)(data + 4);
+
+    k1 *= m; 
+    k1 ^= k1 >> r; 
+    k1 *= m; 
+
+    k2 *= m; 
+    k2 ^= k2 >> r; 
+    k2 *= m; 
+
+    // Mix 4 bytes at a time into the hash
+
+    h *= m; 
+    h ^= k1;
+    h *= m; 
+    h ^= k2;
+
+    // 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;
+}