NAME App::Cache - Easy application-level caching SYNOPSIS # in your class: my $cache = App::Cache->new({ ttl => 60*60 }); $cache->delete('test'); my $data = $cache->get('test'); my $code = $cache->get_code("code", sub { $self->calculate() }); my $html = $cache->get_url("http://www.google.com/"); $cache->set('test', 'one'); $cache->set('test', { foo => 'bar' }); my $scratch = $cache->scratch; $cache->clear; DESCRIPTION The App::Cache module lets an application cache data locally. There are a few times an application would need to cache data: when it is retrieving information from the network or when it has to complete a large calculation. For example, the Parse::BACKPAN::Packages module downloads a file off the net and parses it, creating a data structure. Only then can it actually provide any useful information for the programmer. Parse::BACKPAN::Packages uses App::Cache to cache both the file download and data structures, providing much faster use when the data is cached. This module stores data in the home directory of the user, in a dot directory. For example, the Parse::BACKPAN::Packages cache is actually stored underneath "~/.parse_backpan_packages/cache/". This is so that permisssions are not a problem - it is a per-user, per-application cache. METHODS new The constructor creates an App::Cache object. It takes two optional parameters: a ttl parameter which contains the number of seconds in which a cache entry expires, and an application parameter which signifies the application name. If you are calling new() from a class, the application is automagically set to the calling class, so you should rarely need to pass it in: my $cache = App::Cache->new({ ttl => 60*60 }); clear Clears the cache: $cache->clear; delete Deletes an entry in the cache: $cache->delete('test'); get Gets an entry from the cache. Returns undef if the entry does not exist or if it has expired: my $data = $cache->get('test'); get_code This is a convenience method. Gets an entry from the cache, but if the entry does not exist, set the entry to the value of the code reference passed: my $code = $cache->get_code("code", sub { $self->calculate() }); get_url This is a convenience method. Gets the content of a URL from the cache, but if the entry does not exist, set the entry to the content of the URL passed: my $html = $cache->get_url("http://www.google.com/"); scratch Returns a directory in the cache that the application may use for scratch files: my $scratch = $cache->scratch; set Set an entry in the cache. Note that an entry value may be an arbitrary Perl data structure: $cache->set('test', 'one'); $cache->set('test', { foo => 'bar' }); AUTHOR Leon Brocard COPYRIGHT Copyright (C) 2005, Leon Brocard This module is free software; you can redistribute it or modify it under the same terms as Perl itself. 1;