NAME

DBIx::VersionedSubs::AutoLoad - autoload subroutines from the database

SYNOPSIS

  package My::App;
  use strict;
  use base 'DBIx::VersionedSubs::AutoLoad';

  package main;
  use strict;

  My::App->startup($dsn);
  while (my $request = Some::Server->get_request) {
      My::App->update_code; # update code from the DB
      My::App->handle_request($request);
  }

ABSTRACT

This module overrides some methods in DBIx::VersionedSubs to prevent loading of the whole code at startup and installs an AUTOLOAD handler to load the needed code on demand. This is useful if startup time is more important than response time or you fork() before loading the code from the database.

CAVEATS

You should be able to switch between the two implementations without almost any further code changes. There is one drawback of the AUTOLOAD implementation:

Preexisting functions don't get overwritten from the database

You need to explicitly load functions from the database that you wish to overwrite Perl code obtained from elsewhere.

This is the price you pay for using AUTOLOAD.

CLASS METHODS

__PACKAGE__->init_code

Overridden to just install the AUTOLOAD handler.

__PACKAGE__->install_and_invoke NAME, ARGS

Loads code from the database, installs it into the namespace and immediately calls it with the remaining arguments via goto &code;.

If no row with a matching name exists, an error is raised.

__PACKAGE__->update_code

Overridden to do lazy updates. It wipes all code that is out of date from the namespace and lets the AUTOLOAD handler sort out the reloading.

__PACKAGE__->load_code NAME

Retrieves the code for the subroutine NAME from the database and calls __PACKAGE__->install_code $name,$code to install it.

__PACKAGE__->retrieve_code NAME

Retrieves the code for the subroutine NAME from the database and returns it as a string.

INSTALLED CODE

AUTOLOAD

An AUTOLOAD handler is installed to manage the loading of code that has not been retrieved from the database yet. If another AUTOLOAD handler already exists, the AUTOLOAD handler is not installed and a warning is issued.

BUGS

• Currently, if a routine gets changed, the AUTOLOAD handler is not fired directly but by using a callback. This is because I couldn't delete the typeglob properly such that the AUTOLOAD fires again.

AUTHOR

Max Maischein, <corion@cpan.org>

LICENSE

This module is licensed under the same terms as Perl itself.