Before anything else, let me state this: Of course it's going to be
PAINFULLY slow on MRI.  That's not the point :)

I thought I'd try out writing out a Ruby version of the parser for the
purposes of Rubinius.  For those of you who aren't aware, Ragel supports a
goto-driven FSM on Rubinius by injecting assembly directly, and Rubinus head
honcho guy Evan Phoenix is working on a patch for Ragel to update it to the
new compiler semantics.  So really, there is a purpose for trying this out.

Anyway, here's my initial hack.  It's nasty, and presently jams the entire
FSM into instance-specific data.  Aieee!  But it more or less seems to
generate similar (albeit not identical) output to the C one:

http://git.rubini.us/?p=code;a=blob;f=lib/mongrel/http11_parser.rb.rl;h=508f9bd42b4aad322f357637d52576f780707a2f;hb=868732662abbf4aa571bf2f3d598152467f6f4da

I've thought about having a Mongrel::HttpParser::FSM module to store the
actual Ragel-generated state machine, and pass all ivars from the
Mongrel::HttpParser to an execute method then recapture them as return
values, or something to that effect.

Thoughts?  Suggestions?  Complete rewrites?  I'd appreciate them all.

-- 
Tony Arcieri
medioh.com