I think that <a href="http:&#x2F;&#x2F;www.ucw.cz&#x2F;holmes&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.ucw.cz&#x2F;holmes&#x2F;</a> has (or had) an HTTP parser based on perfect hashing of strings for maybe 15 years. It was written by some very smart people and there are lot of tricks like that in these sources.