General Purpose Hash Functions Gem
hashfunctions is a Ruby gem which implements 11 fast hash functions for general purpose non-cryptographic use implemented originally by Arash Partow. Part of this library is the native C hashfunctions-extension extension which is used if it's installed as gem.
require "general-hash-functions" hash = GeneralHashFunctions::djbhash("some string") # will return the 395673328
See description of all contained functions at Arash Partow's page: http://www.partow.net/programming/hashfunctions/index.html#AvailableHashFunctions