Poet::Cache -- Poet caching with CHI

       Jonathan Swartz <swartz@pobox.com>

       The Poet configuration entry 'cache', if any, will be passed to Poet::Cache->config(). This can go in any
       Poet conf file, e.g. "local.cfg" or "global/cache.cfg".

       Here's a simple configuration that caches everything to files under "data/cache". This is also the
       default if no configuration is present.

          cache:
             defaults:
                driver: File
                root_dir: ${root}/data/cache

       Here's a more involved configuration that defines several "storage types" and assigns each namespace a
       storage type.

          cache:
             defaults:
                expires_variance: 0.2
             storage:
                file:
                   driver: File
                   root_dir: ${root}/data/cache
                memcached:
                   driver: Memcached
                   servers: ["10.0.0.15:11211", "10.0.0.15:11212"]
                   compress_threshold: 4096
             namespace:
                /some/component:       { storage: file, expires_in: 5min }
                /some/other/component: { storage: memcached, expires_in: 1h }
                Some::Library:         { storage: memcached, expires_in: 10min }

       Given the configuration above, and the code

           package Some::Library;
           use Poet qw($cache);

       this $cache will be created with properties

           driver: Memcached
           servers: ["10.0.0.15:11211", "10.0.0.15:11212"]
           compress_threshold: 4096
           expires_in: 10min

       This software is copyright (c) 2012 by Jonathan Swartz.

       This  is  free  software;  you  can  redistribute  it and/or modify it under the same terms as the Perl 5
       programming language system itself.

perl v5.34.0                                       2022-06-18                                   Poet::Cache(3pm)

       Poet::Cache is a subclass of CHI. CHI provides a unified caching API over a variety of storage backends,
       such as memory, plain files, memory mapped files, memcached, and DBI.

       Each package and Mason component uses its own CHI namespace so that caches remain separate.

       These  methods  are  not  intended  to be called externally, but may be useful to override or modify with
       method modifiers in subclasses.

       initialize_caching
           Called once when the Poet environment is initialized. By default,  calls  "__PACKAGE__->config"  with
           the configuration entry 'cache'.

       Poet::Cache -- Poet caching with CHI

       Poet

           # In a conf file...
           cache:
              defaults:
                 driver: Memcached
                 servers: ["10.0.0.15:11211", "10.0.0.15:11212"]

           # In a script...
           use Poet::Script qw($cache);

           # In a module...
           use Poet qw($cache);

           # In a component...
           my $cache = $m->cache;

           # For an arbitrary namespace...
           my $cache = Poet::Cache->new(namespace => 'Some::Namespace')

           # then...
           my $customer = $cache->get($name);
           if ( !defined $customer ) {
               $customer = get_customer_from_db($name);
               $cache->set( $name, $customer, "10 minutes" );
           }
           my $customer2 = $cache->compute($name2, "10 minutes", sub {
               get_customer_from_db($name2)
           });

Obtainingcachehandle
       •   In a script (namespace will be 'main'):

               use Poet::Script qw($cache);

       •   In a module "MyApp::Foo" (namespace will be 'MyApp::Foo'):

               use Poet qw($cache);

       •   In a component "/foo/bar" (namespace will be '/foo/bar'):

               my $cache = $m->cache;

       •   Manually for an arbitrary namespace:

               my $cache = Poet::Cache->new(namespace => 'Some::Namespace');

               # or

               my $cache = MyApp::Cache->new(category => 'Some::Namespace');

   Usingcachehandle
           my $customer = $cache->get($name);
           if ( !defined $customer ) {
               $customer = get_customer_from_db($name);
               $cache->set( $name, $customer, "10 minutes" );
           }
           my $customer2 = $cache->compute($name2, "10 minutes", sub {
               get_customer_from_db($name2)
           });

       See CHI and Mason::Plugin::Cache for more details.