codewings · February 18, 2014 07:59 · Feb 18, 2014
diff --git a/MurmurHash64B b/MurmurHash64B
@@ -0,0 +1,56 @@
+def bytes_to_int32(bytes):
+    assert len(bytes) == 4
+    return sum((b << (k * 8) for k, b in enumerate(bytes)))
+
+def MurmurHash64B(data, seed):
+    m = 0x5bd1e995
+    r = 24    
+    MASK = 0xFFFFFFFF
+    data_as_bytes = bytearray(data)
+
+    length = len(data_as_bytes) & MASK
+    h1 = (seed & MASK) ^ length;
+    h2 = 0;
+
+    index = 0
+    while(length >= 8):
+        k1 = bytes_to_int32(data_as_bytes[index:index+4])
+        k1 = (k1 * m) & MASK; k1 = k1 ^ ((k1 >> r) & MASK); k1 = (k1 * m) & MASK;
+        h1 = (h1 * m) & MASK; h1 = h1 ^ k1;
+        length -= 4;
+        index  += 4;
+
+        k2 = bytes_to_int32(data_as_bytes[index:index+4])
+        k2 = (k2 * m) & MASK; k2 = k2 ^ ((k2 >> r) & MASK); k2 = (k2 * m) & MASK;
+        h2 = (h2 * m) & MASK; h2 = h2 ^ k2;
+        length -= 4;
+        index  += 4;
+
+    if(length >= 4):
+    k3 = bytes_to_int32(data_as_bytes[index:index+4])
+    k3 = (k3 * m) & MASK; k3 = k3 ^ ((k3 >> r) & MASK); k3 = (k3 * m) & MASK;
+    h1 = (h1 * m) & MASK; h1 = h1 ^ k3;
+    length -= 4;
+    index  += 4;
+
+    if(length == 3):
+    h2 = h2 ^ ((data_as_bytes[index+2] << 16) & MASK )
+    h2 = h2 ^ ((data_as_bytes[index+1] << 8 ) & MASK )
+    h2 = h2 ^ (data_as_bytes[index+0])
+    h2 = (h2 * m) & MASK;
+    if(length == 2):
+    h2 = h2 ^ ((data_as_bytes[index+1] << 8 ) & MASK )
+    h2 = h2 ^ (data_as_bytes[index+0])
+    h2 = (h2 * m) & MASK;
+    if(length == 1):
+    h2 = h2 ^ (data_as_bytes[index+0])
+    h2 = (h2 * m) & MASK;
+
+    h1 = h1 ^ ((h2 >> 18) & MASK ); h1 = (h1 * m) & MASK;
+    h2 = h2 ^ ((h1 >> 22) & MASK ); h2 = (h2 * m) & MASK;
+    h1 = h1 ^ ((h2 >> 17) & MASK ); h1 = (h1 * m) & MASK;
+    h2 = h2 ^ ((h1 >> 19) & MASK ); h2 = (h2 * m) & MASK;
+
+    h = h1;
+    h = ((h << 32) & 0xFFFFFFFFFFFFFFFF) | h2;    
+    return h