use strict;
use warnings;
+our $VERSION = "0.01";
+
use Scalar::Util ();
use Catalyst::Utils ();
use Carp ();
if ( !$app->get_cache_backend("default") ) {
local $@;
eval { $app->setup_generic_cache_backend( default => $app->get_default_cache_backend_config || {} ) };
- }
+ }
}
sub default_cache_store {
for my $i ( 0 .. 15 ) { # don't look to far
my @info = caller(2 + $i) or last;
- $caller ||= \@info unless $info[0] =~ /Catalyst::Plugin::Cache/;
+ $caller ||= \@info unless $info[0] =~ /Plugin::Cache/;
$component ||= \@info if $info[0]->isa("Catalyst::Component");
$controller ||= \@info if $info[0]->isa("Catalyst::Controller");
last if $caller && $component && $controller;
}
+ my ( $caller_pkg, $component_pkg, $controller_pkg ) =
+ map { $_ ? $_->[0] : undef } $caller, $component, $controller;
+
return (
- 'caller' => $caller,
- component => $component,
- controller => $controller,
+ 'caller' => $caller_pkg,
+ component => $component_pkg,
+ controller => $controller_pkg,
+ caller_frame => $caller,
+ component_frame => $component,
+ controller_frame => $controller,
);
}
sub choose_cache_backend_wrapper {
my ( $c, @meta ) = @_;
- Carp::croak("meta data must be an even sized list") unless @meta % 2 == 0;
+ Carp::croak("metadata must be an even sized list") unless @meta % 2 == 0;
my %meta = @meta;
=head1 NAME
-Catalyst::Plugin::Cache -
+Catalyst::Plugin::Cache - Flexible caching support for Catalyst.
=head1 SYNOPSIS
/;
# configure a backend or use a store plugin
- __PACKAGE__->config( cache => {
- backend => {
- class => "Cache::Bounded",
- # ... params ...
- },
- });
+ __PACKAGE__->config->{cache}{backend} = {
+ class => "Cache::Bounded",
+ # ... params ...
+ };
- # ... in a controller
+ # In a controller:
sub foo : Local {
my ( $self, $c, $id ) = @_;
my $result;
unless ( $result = $cache->get( $id ) ) {
- # ... calulate result ...
+ # ... calculate result ...
$c->cache->set( $id, $result );
}
};
=head1 DESCRIPTION
-This plugin allows you to use a very simple configuration API without losing
-the possibility of flexibility when you need it later.
+This plugin gives you access to a variety of systems for caching
+data. It allows you to use a very simple configuration API, while
+maintaining the possibility of flexibility when you need it later.
+
+Among its features are support for multiple backends, segmentation based
+on component or controller, keyspace partitioning, and so more, in
+various subsidiary plugins.
+
+=head1 METHODS
+
+=over 4
+
+=item cache $profile_name
+
+=item cache %meta
+
+Return a curried object with metadata from C<$profile_name> or as
+explicitly specified.
+
+If a profile by the name C<$profile_name> doesn't exist, but a backend
+object by that name does exist, the backend will be returned instead,
+since the interface for curried caches and backends is almost identical.
+
+This method can also be called without arguments, in which case is
+treated as though the C<%meta> hash was empty.
+
+See L</METADATA> for details.
+
+=item curry_cache %meta
+
+Return a L<Catalyst::Plugin::Cache::Curried> object, curried with C<%meta>.
+
+See L</METADATA> for details.
+
+=item cache_set $key, $value, %meta
+
+=item cache_get $key, %meta
+
+=item cache_remove $key, %meta
+
+These cache operations will call L<choose_cache_backend> with %meta, and
+then call C<set>, C<get>, or C<remove> on the resulting backend object.
+
+=item choose_cache_backend %meta
+
+Select a backend object. This should return undef if no specific backend
+was selected - its caller will handle getting C<default_cache_backend>
+on its own.
+
+This method is typically used by plugins.
+
+=item get_cache_backend $name
+
+Get a backend object by name.
+
+=item default_cache_backend
+
+Return the default backend object.
+
+=item temporary_cache_backend
+
+When no default cache backend is configured this method might return a
+backend known to work well with the current L<Catalyst::Engine>. This is
+a stub.
+
+=item
+
+=back
+
+=head1 METADATA
+
+=head2 Introduction
+
+Whenever you set or retrieve a key you may specify additional metadata
+that will be used to select a specific backend.
+
+This metadata is very freeform, and the only key that has any meaning by
+default is the C<backend> key which can be used to explicitly choose a backend
+by name.
+
+The C<choose_cache_backend> method can be overridden in order to
+facilitate more intelligent backend selection. For example,
+L<Catalyst::Plugin::Cache::Choose::KeyRegexes> overrides that method to
+select a backend based on key regexes.
+
+Another example is a L<Catalyst::Plugin::Cache::ControllerNamespacing>,
+which wraps backends in objects that perform key mangling, in order to
+keep caches namespaced per controller.
+
+However, this is generally left as a hook for larger, more complex
+applications. Most configurations should make due XXXX
+
+The simplest way to dynamically select a backend is based on the
+L</Cache Profiles> configuration.
+
+=head2 Meta Data Keys
+
+C<choose_cache_backend> is called with some default keys.
+
+=over 4
+
+=item key
+
+Supplied by C<cache_get>, C<cache_set>, and C<cache_remove>.
+
+=item value
+
+Supplied by C<cache_set>.
+
+=item caller
+
+The package name of the innermost caller that doesn't match
+C<qr/Plugin::Cache/>.
+
+=item caller_frame
+
+The entire C<caller($i)> frame of C<caller>.
+
+=item component
+
+The package name of the innermost caller who C<isa>
+L<Catalyst::Component>.
+
+=item component_frame
+
+This entire C<caller($i)> frame of C<component>.
+
+=item controller
+
+The package name of the innermost caller who C<isa>
+L<Catalyst::Controller>.
-Amongst it's features are support for multiple backends, segmentation based on
-component or controller, keyspace partitioning and so forth, in various sub
-plugins.
+=item controller_frame
+
+This entire C<caller($i)> frame of C<controller>.
+
+=back
+
+=head2 Metadata Currying
+
+In order to avoid specifying C<%meta> over and over again you may call
+C<cache> or C<curry_cache> with C<%meta> once, and get back a B<curried
+cache object>. This object responds to the methods C<get>, C<set>, and
+C<remove>, by appending its captured metadata and delegating them to
+C<cache_get>, C<cache_set>, and C<cache_remove>.
+
+This is simpler than it sounds.
+
+Here is an example using currying:
+
+ my $cache = $c->cache( %meta ); # cache is curried
+
+ $cache->set( $key, $value );
+
+ $cache->get( $key );
+
+And here is an example without using currying:
+
+ $c->cache_set( $key, $value, %meta );
+
+ $c->cache_get( $key, %meta );
+
+See L<Catalyst::Plugin::Cache::Curried> for details.
=head1 CONFIGURATION
- $c->config->{cache} = {
- backend => '',
- };
+ $c->config->{cache} = {
+ ...
+ };
+
+All configuration parameters should be provided in a hash reference
+under the C<cache> key in the C<config> hash.
+
+=head2 Backend Configuration
-All configuration parameters should be provided in a hash reference under the
-C<cache> key in the C<config> hash.
+Configuring backend objects is done by adding hash entries under the
+C<backends> key in the main config.
+
+A special case is that the hash key under the C<backend> (singular) key
+of the main config is assumed to be the backend named C<default>.
=over 4
=item class
-Load an entire set of Caching modules.
+Instantiate a backend from a L<Cache> compatible class. E.g.
-=item backend
+ $c->config->{cache}{backends}{small_things} = {
+ class => "Cache::Bounded",
+ interval => 1000,
+ size => 10000,
+ };
+
+ $c->config->{cache}{backends}{large_things} = {
+ class => "Cache::Memcached::Managed",
+ data => '1.2.3.4:1234',
+ };
-The specific backend you want to use.
+The options in the hash are passed to the class's C<new> method.
-=item backends
+The class will be C<required> as necessary during setup time.
-A hashref with backend names as keys, and module names as values. One of these
-should have the key "default" to indicate the default backend.
+=item store
-=item default_store
+Instantiate a backend using a store plugin, e.g.
+
+ $c->config->{cache}{backend} = {
+ store => "FastMmap",
+ };
-The store you are using. This must be supplied if you have loaded multiple
-store plugins.
+Store plugins typically require less configuration because they are
+specialized for L<Catalyst> applications. For example
+L<Catalyst::Plugin::Cache::Store::FastMmap> will specify a default
+C<share_file>, and additionally use a subclass of L<Cache::FastMmap>
+that can also store non reference data.
-=item curried_class
+The store plugin must be loaded.
-The currying class you are using, defaults to L<Catalyst::Plugin::Cache::Curried>.
+=back
+
+=head2 Cache Profiles
+
+=over 4
=item profiles
-Supply your own predefined profiles for cache namespacing.
-
+Supply your own predefined profiles for cache metadata, when using the
+C<cache> method.
+
+For example when you specify
+
+ $c->config->{cache}{profiles}{thumbnails} = {
+ backend => "large_things",
+ };
+
+And then get a cache object like this:
+
+ $c->cache("thumbnails");
+
+It is the same as if you had done:
+
+ $c->cache( backend => "large_things" );
+
+=back
+
+=head2 Miscellaneous Configuration
+
+=over 4
+
+=item default_store
+
+When you do not specify a C<store> parameter in the backend
+configuration this one will be used instead. This configuration
+parameter is not necessary if only one store plugin is loaded.
=back
=item store
-A plugin that provides backends of a certain type. This is a bit like a factory.
+A plugin that provides backends of a certain type. This is a bit like a
+factory.
=item cache
Stored key/value pairs of data for easy re-access.
+=item metadata
+
+"Extra" information about the item being stored, which can be used to
+locate an appropriate backend.
+
=item curried cache
my $cache = $c->cache(type => 'thumbnails');
$cache->set('pic01', $thumbnaildata);
-A cache which has been pre-configured with a particular set of namespacing
-data. In the example the cache returned could be one specifically tuned
-for storing thumbnails.
+A cache which has been pre-configured with a particular set of
+namespacing data. In the example the cache returned could be one
+specifically tuned for storing thumbnails.
-An object that responds to C<get>, C<set> and C<remove>, and will automatically
-add meta data to calls to C<< $c->cache_get >>, etc.
+An object that responds to C<get>, C<set>, and C<remove>, and will
+automatically add metadata to calls to C<< $c->cache_get >>, etc.
=back
-=cut
+=head1 SEE ALSO
+
+L<Cache> - the generic cache API on CPAN.
+
+L<Catalyst::Plugin::Cache::Store> - how to write a store plugin.
+
+L<Catalyst::Plugin::Cache::Curried> - the interface for curried caches.
+
+L<Catalyst::Plugin::Cache::Choose::KeyRegexes> - choose a backend based on
+regex matching on the keys. Can be used to partition the keyspace.
+L<Catalyst::Plugin::Cache::ControllerNamespacing> - wrap backend objects in a
+name mangler so that every controller gets its own keyspace.
+
+=head1 AUTHOR
+
+Yuval Kogman, C<nothingmuch@woobling.org>
+
+=head1 COPYRIGHT & LICENSE
+
+Copyright (c) Yuval Kogman, 2006. All rights reserved.
+
+This library is free software, you can redistribute it and/or modify it under
+the same terms as Perl itself, as well as under the terms of the MIT license.
+
+=cut
projects / catagits/Catalyst-Plugin-Cache.git / blobdiff