Skip to content
Find file
Fetching contributors…
Cannot retrieve contributors at this time
171 lines (117 sloc) 4.1 KB
package Poet::Cache; ## no critic (Moose::RequireMakeImmutable)
use Poet qw($conf $poet);
use Method::Signatures::Simple;
use Moose;
extends 'CHI';
method initialize_caching () {
my $default_config =
{ defaults => { driver => 'File', root_dir => $poet->data_path("cache") } };
my $config = $conf->get_hash( 'cache' => $default_config );
__PACKAGE__->config($config);
}
1;
=pod
=head1 NAME
Poet::Cache -- Poet caching with CHI
=head1 SYNOPSIS
# 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)
});
=head1 DESCRIPTION
Poet::Cache is a subclass of L<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 L<namespace|CHI/namespace> so
that caches remain separate.
=head1 CONFIGURATION
The Poet configuration entry 'cache', if any, will be passed to
L<Poet::Cache-E<gt>config()|CHI/SUBCLASSING AND CONFIGURING CHI>. This can go
in any L<Poet conf file|Poet::Conf/CONFIGURATION FILES>, e.g. C<local.cfg> or
C<global/cache.cfg>.
Here's a simple configuration that caches everything to files under
C<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 C<$cache> will be created with properties
driver: Memcached
servers: ["10.0.0.15:11211", "10.0.0.15:11212"]
compress_threshold: 4096
expires_in: 10min
=head1 USAGE
=head2 Obtaining cache handle
=over
=item *
In a script (namespace will be 'main'):
use Poet::Script qw($cache);
=item *
In a module C<MyApp::Foo> (namespace will be 'MyApp::Foo'):
use Poet qw($cache);
=item *
In a component C</foo/bar> (namespace will be '/foo/bar'):
my $cache = $m->cache;
=item *
Manually for an arbitrary namespace:
my $cache = Poet::Cache->new(namespace => 'Some::Namespace');
# or
my $cache = MyApp::Cache->new(category => 'Some::Namespace');
=back
=head2 Using cache handle
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 L<CHI|CHI> and L<Mason::Plugin::Cache|Mason::Plugin::Cache> for more
details.
=head1 MODIFIABLE METHODS
These methods are not intended to be called externally, but may be useful to
override or modify with method modifiers in L<subclasses|/Poet::Subclassing>.
=over
=item initialize_caching
Called once when the Poet environment is initialized. By default, calls C<<
__PACKAGE__->config >> with the configuration entry 'cache'.
=back
Something went wrong with that request. Please try again.