[erlang-questions] Introspecting the atom table

Jani Hakala <>
Thu Dec 21 03:34:07 CET 2006


"Yariv Sadan" <> writes:

> Instead of converting
> controller/function names of incoming requests to atoms, ErlyWeb looks
> them up in the gb_trees structure for the application. This is how
> ErlyWeb avoids allocating atoms for incoming requests.
>
> I hope this approach has similar performance to checking the existence
> of atoms. Does anybody think the latter is better?
>
gb_trees is O(log(n)) and atom things are O(1) (atom table seems to be
a hash), and list_to_existing_atom seems to be a BIF. I would be
surprised if list_to_existing_atom() didn't win in a performance
test. 

Jani Hakala



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