Peter Dimov wrote:
Daniel James wrote:
Well, these two pages describe algorithms for hashing strings, which apparently are faster with good (or better?) quality (I haven't tested them yet):
http://burtleburtle.net/bob/hash/doobs.html http://www.azillionmonkeys.com/qed/hash.html
These pages are good.
But as I said, benchmarking hash functions is pointless. Real programs do not compute the hash value of a random 256 byte buffer five million times. They usually need to do something with the hash value. This something typically involves a division on a prime to obtain a modulus, several pointer chasings, and at least one equality comparison (which on a 256 byte buffer will have considerable impact).
Actually, that's one of the problems with them. They're designed to be used with hash tables that have a 2^n buckets (to avoid calculating the modulus), which isn't practical for a generic hash table that supports user supplied hash functions. Daniel