On Sat, Nov 24, 2012 at 5:09 AM, André Warnier <a...@ice-sa.com> wrote: > For the PerlFixupHandler which was discussed before, I need to compare the > current request URL to a predefined static list of URLs, to decide how > exactly to proxy this call. > At the moment, there are about 15 URLs in that list; and I believe that > there might, maybe in some cases, be up to 100.
Maybe read the variables in startup.pl, and setup a package to provide them to other modules at runtime? http://perl.apache.org/docs/2.0/user/handlers/server.html#Startup_File # pass $urllist var from httpd.conf? startup.pl: > my $fh; > open($fh,'<',$urllist) or safe_die; > my @list = <$fh>; > close $fh; My::Proxy->set_urllist(\@list); There are a few different ways to specify $urllist in httpd.conf I think so that startup.pl can get at it at startup time. Remember that startup.pl is actually read twice I think (when apache starts, it starts twice to make sure it can survive a restart). http://perl.apache.org/docs/2.0/api/Apache2/ServerUtil.html#C_restart_count_ Hope that helps - there are some details I'm probably glossing over here. > > I suppose that I could make this list of URLs available to the handler by > doing something like this : > > <Location /> > ... > PerlFixupHandler My::Proxy->handler > PerlAddVar CHKU "http://www.site-1.com/"; > PerlAddVar CHKU "http://www.site-2.org/path?query"; > PerlAddVar CHKU "http://www.site-3.biz/"; > PerlAddVar CHKU "http://www.site-4.edu/"; > etc.. 50 times > </Location> > > and then do > my @list = $r->dir_config('CHKU'); > in the handler. > > On the other hand, I could also put these URLs in a separate configuration > text file, and have the handler read it at each invocation : > > <Location /> > ... > PerlFixupHandler My::Proxy->handler > PerlSetVar URL_LIST "/etc/apache2/conf/urllist.txt" > </Location> > > and in the handler : > > my $urllist = $r->dir_config('URL_LIST') || "default.list"; > my @list = (); > my $fh; > open($fh,'<',$urllist) or safe_die; > @list = <$fh>; > close $fh; > > But neither of these is very satisfying. > The first one above is OK up to 10-20 URLs, but becomes a bit unsightly and > clumsy for more. > The second one has the handler read and parse a file at each invocation > (even if the request URL turns out not to be in the list, and the call > should just be proxy-ed as is). > Sounds inefficient. > > So, I would like to do this : > > Package My::Proxy; > > our $URLS; > > sub handler { > my $r = shift; > unless (defined($URLS)) { > my $urllist = $r->dir_config('URL_LIST') || > "/etc/apache2/default_urls.list"; > my $fh; > my @list; > open($fh,'<',$urllist) or safe_die; > @list = <$fh>; > close $fh; > $URLS = \@list; # or = [ @list ] ?? > } > .. use @$URLS, read-only .. > > > } > > As I understand the above, in a pre-fork MPM, each time Apache forks a new > child, at the first handler invocation $URLS will be undef, and thus the > code in the handler will define it, as a reference to an array of URLs read > from the file. > And from then on, the list accessible through $URLS should remain available > and unvariable at each subsequent invocation of this handler (in this > child), as long as this Apache child process lives. > > First, I may be wrong in my understanding. (that's a question). > > Second, if I am right in the above, then does this same understanding extend > to all possible Apache MPMs ? Or am I creating a horrible risk of some race > condition, or memory leak here ? > > > > > >
