This is a very fast, non-cryptographic hash suitable for general hash-based lookup. See
http://murmurhash.googlepages.com/ for more details.
The C version of MurmurHash 2.0 found at that site was ported to Java by Andrzej Bialecki (ab at
getopt org): http://www.getopt.org/murmur/MurmurHash.java