https://www.cs.cmu.edu/~dga/papers/cuckoo-conext2014.pdf 检验hash冲突

https://github.com/google/cityhash 

We like to test hash functions with SMHasher, among other things.
SMHasher isn't perfect, but it seems to find almost any significant flaw.
SMHasher is available at http://code.google.com/p/smhasher/