NAME¶
ModPerl::RegistryLoader - Compile ModPerl::RegistryCooker scripts at server
startup
Synopsis¶
# in startup.pl
use ModPerl::RegistryLoader ();
use File::Spec ();
# explicit uri => filename mapping
my $rlbb = ModPerl::RegistryLoader->new(
package => 'ModPerl::RegistryBB',
debug => 1, # default 0
);
$rlbb->handler($uri, $filename);
###
# uri => filename mapping using a helper function
sub trans {
my $uri = shift;
$uri =~ s|^/registry/|cgi-bin/|;
return File::Spec->catfile(Apache2::ServerUtil::server_root, $uri);
}
my $rl = ModPerl::RegistryLoader->new(
package => 'ModPerl::Registry',
trans => \&trans,
);
$rl->handler($uri);
###
$rlbb->handler($uri, $filename, $virtual_hostname);
Description¶
This modules allows compilation of scripts, running under packages derived from
"ModPerl::RegistryCooker", at server startup. The script's handler
routine is compiled by the parent server, of which children get a copy and
thus saves some memory by initially sharing the compiled copy with the parent
and saving the overhead of script's compilation on the first request in every
httpd instance.
This module is of course useless for those running the
"ModPerl::PerlRun" handler, because the scripts get recompiled on
each request under this handler.
Methods¶
- new()
- When creating a new "ModPerl::RegistryLoader" object, one has to
specify which of the "ModPerl::RegistryCooker" derived modules
to use. For example if a script is going to run under
"ModPerl::RegistryBB" the object is initialized as:
my $rlbb = ModPerl::RegistryLoader->new(
package => 'ModPerl::RegistryBB',
);
If the package is not specified "ModPerl::Registry" is assumed:
my $rlbb = ModPerl::RegistryLoader->new();
To turn the debugging on, set the debug attribute to a true value:
my $rlbb = ModPerl::RegistryLoader->new(
package => 'ModPerl::RegistryBB',
debug => 1,
);
Instead of specifying explicitly a filename for each uri passed to
handler(), a special attribute trans can be set to a
subroutine to perform automatic remapping.
my $rlbb = ModPerl::RegistryLoader->new(
package => 'ModPerl::RegistryBB',
trans => \&trans,
);
See the handler() item for an example of using the trans
attribute.
- handler()
-
$rl->handler($uri, [$filename, [$virtual_hostname]]);
The handler() method takes argument of "uri" and optionally
of "filename" and of "virtual_hostname".
URI to filename translation normally doesn't happen until HTTP request time,
so we're forced to roll our own translation. If the filename is supplied
it's used in translation.
If the filename is omitted and a "trans" subroutine was not set in
new(), the loader will try using the "uri" relative to
the "ServerRoot" configuration directive. For example:
httpd.conf:
-----------
ServerRoot /usr/local/apache
Alias /registry/ /usr/local/apache/cgi-bin/
startup.pl:
-----------
use ModPerl::RegistryLoader ();
my $rl = ModPerl::RegistryLoader->new(
package => 'ModPerl::Registry',
);
# preload /usr/local/apache/cgi-bin/test.pl
$rl->handler(/registry/test.pl);
To make the loader smarter about the URI->filename translation, you may
provide the "new()" method with a "trans()" function
to translate the uri to filename.
The following example will pre-load all files ending with .pl in the
cgi-bin directory relative to "ServerRoot".
httpd.conf:
-----------
ServerRoot /usr/local/apache
Alias /registry/ /usr/local/apache/cgi-bin/
startup.pl:
-----------
{
# test the scripts pre-loading by using trans sub
use ModPerl::RegistryLoader ();
use File::Spec ();
use DirHandle ();
use strict;
my $dir = File::Spec->catdir(Apache2::ServerUtil::server_root,
"cgi-bin");
sub trans {
my $uri = shift;
$uri =~ s|^/registry/|cgi-bin/|;
return File::Spec->catfile(Apache2::ServerUtil::server_root,
$uri);
}
my $rl = ModPerl::RegistryLoader->new(
package => "ModPerl::Registry",
trans => \&trans,
);
my $dh = DirHandle->new($dir) or die $!;
for my $file ($dh->read) {
next unless $file =~ /\.pl$/;
$rl->handler("/registry/$file");
}
}
If $virtual_hostname argument is passed it'll be used in the creation of the
package name the script will be compiled into for those registry handlers
that use namespace_from_uri() method. See also the
notes on $ModPerl::RegistryCooker::NameWithVirtualHost in the
"ModPerl::RegistryCooker" documentation.
Also explained in the "ModPerl::RegistryLoader" documentation,
this only has an effect at run time if
$ModPerl::RegistryCooker::NameWithVirtualHost is set to true, otherwise
the $virtual_hostname argument is ignored.
Implementation Notes¶
"ModPerl::RegistryLoader" performs a very simple job, at run time it
loads and sub-classes the module passed via the
package attribute and
overrides some of its functions, to emulate the run-time environment. This
allows one to preload the same script into different registry environments.
Authors¶
The original "Apache2::RegistryLoader" implemented by Doug MacEachern.
Stas Bekman did the porting to the new registry framework based on
"ModPerl::RegistryLoader".
SEE ALSO¶
"ModPerl::RegistryCooker", "ModPerl::Registry",
"ModPerl::RegistryBB", "ModPerl::PerlRun",
Apache(3),
mod_perl(3)