Hi,
As part of my ongoing effort to streamline my mod_perl apps, I've come
to discover the joy of constant subroutines and perl's ability to
inline or eliminate code at compile time. I have a solution that
works, but would be interested in seeing if others had better
syntactic sugar.. Anyway:
We have a module CP::Util, with this begin block:
BEGIN {
$ENV{CP_DEBUG} ||= 0;
if ($ENV{CP_DEBUG} == 1) {
*{CP::Util::DBG} = sub () {1;};
} else {
*{CP::Util::DBG} = sub () {0;};
}
}
@EXPORT_OK = qw(DBG);
Then, in another module I do:
use CP::Util qw(DBG);
DBG && debug('whoa there boy');
The end result is, when CP_DEBUG=1, the code is in there. When
CP_DEBUG=0, the code is trimmed out at compile time (because DBG is a
constant subroutine, see perldoc perlsub for more info)
This is a real win compared to our old way of using a subroutine
called debug that did a no-op. Consider:
debug 'whoa there' . $foo . join(keys(%bar));
The args to debug are still computed, passed on the stack, etc..
Now, my question is: Is there some trick I could use to retain the simple syntax:
debug "foo bar";
In any case I hope the above exercise opens up everyone's eyes. Just
goes to show that your debug statements might actually be slowing your
mod_perl application.
Cheers.
--
Paul Lindner
[EMAIL PROTECTED]
