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Re: Perfect hash function generator



On Wed, Jul 15, 2009 at 10:34:31PM +0100, Alexander Nasonov wrote:
> Mindaugas Rasiukevicius wrote:
> > It is quite specific tool, not really a general purpose functionality.
> > Sure it is small, but just breaks the principle to keep base minimal.
> 
> I'm sure that tool can be useful for generating hashes for things not
> known at build time. Few such use case would make it a less specific tool.
> Off the top of my head, it could be used for generating hashes for big
> pf tables. But I'm not famliar with pf code to prove a usefulness of my
> idea.

Yes, support for dynamically building the perfect hash functions is also
on the list. Different algorithms have different trade offs between
complexity of the hash function, compactness and creation time.

For example, I want to allow an alternative to hash(3). Preliminary
testing shows that it can be done with half an order of magnitude less
space.

Joerg


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