package Gantry::Plugins::Cache::Memcached;
use strict;
use warnings;
use Cache::Memcached;
use Gantry::Plugins::Cache;
use base 'Exporter';
our @EXPORT = qw(
cache_del
cache_get
cache_set
cache_clear
cache_keys
cache_init
cache_purge
cache_handle
cache_inited
cache_expires
cache_namespace
);
sub cache_init {
my ($gobj) = @_;
my $cache;
my $rehash = $gobj->fish_config('cache_rehash') || 'no';
my $expire_time = $gobj->fish_config('cache_expires') || '3600';
my $servers = $gobj->fish_config('cache_servers') || '127.0.0.1:11211';
my $compress = $gobj->fish_config('cache_compress_threshold') || '1000';
my $test_sets = $gobj->fish_config('cache_test_sets') || 0;
eval {
$cache = Cache::Memcached->new({servers => [$servers]});
$cache->set_compress_threshold($compress);
$cache->enable_compress(1);
$cache->set_norehash() if ($rehash =~ /no/i);
# If requested, test cache sets to see if they are successful.
if ($test_sets) {
# Set test.
$cache->set('test-ns:test-var', 1, 120);
# Get test.
my $data = $cache->get('test-ns:test-var');
# Die if set failed.
unless ($data) {
die "Test cache set failed. Please check cache configuration parameters.\n";
}
}
};
if ($@) {
die("Unable to use - Gantry::Cache::Memcached; $@");
}
$gobj->cache_handle($cache);
$gobj->cache_expires($expire_time);
$gobj->cache_inited(1);
}
sub cache_inited {
my ($gobj, $p) = @_;
$$gobj{__CACHE_INITED__} = $p if defined $p;
return($$gobj{__CACHE_INITED__});
}
sub cache_handle {
my ($gobj, $p) = @_;
$$gobj{__CACHE_HANDLE__} = $p if defined $p;
return($$gobj{__CACHE_HANDLE__});
}
sub cache_namespace {
my ($gobj, $p) = @_;
$$gobj{__CACHE_NAMESPACE__} = $p if defined $p;
return($$gobj{__CACHE_NAMESPACE__});
}
sub cache_expires {
my ($gobj, $p) = @_;
$$gobj{__CACHE_EXPIRES__} = $p if defined $p;
return($$gobj{__CACHE_EXPIRES__});
}
sub cache_get {
my ($gobj, $key) = @_;
my $handle = $gobj->cache_handle();
my $namespace = $gobj->cache_namespace();
my $skey = $namespace . ':' . $key;
return $handle->get($skey);
}
sub cache_set {
my ($gobj, $key, $val, $expires) = @_;
# Use global expires if the $expires parameter was not passed in.
$expires ||= $gobj->cache_expires();
my $handle = $gobj->cache_handle();
my $namespace = $gobj->cache_namespace();
my $skey = $namespace . ':' . $key;
$handle->set($skey, $val, $expires);
}
sub cache_clear {
my ($gobj) = @_;
$gobj->cache_handle->flush_all;
}
sub cache_keys {
# currently there is now way to retrieve the cache keys
}
sub cache_del {
my ($gobj, $key) = @_;
my $handle = $gobj->cache_handle();
my $namespace = $gobj->cache_namespace();
my $skey = $namespace . ':' . $key;
$handle->remove($skey);
}
sub cache_purge {
my ($gobj) = @_;
my $handle = $gobj->cache_handle();
return;
}
1;
__END__
=head1 NAME
Gantry::Plugins::Cache::Memcached - A Plugin interface to a caching subsystem
=head1 SYNOPSIS
It is sometimes desirable to cache data between page acceses. This
module gives access to the Cache::Memcached module to store that data.
<Perl>
# ...
use MyApp qw{ -Engine=CGI -TemplateEngine=TT Cache::Memcached };
</Perl>
=head1 DESCRIPTION
This plugin mixes in methods to store data within a cache. This data
is then available for later retrival. Data is stored within the cache
by key/value pairs. There are no restrictions on what information can be
stored. This cache is designed for short term data storage. Cached
data items will be timed out and purged at regular intervals. The caching
system also has the concept of namespace. Namespaces are being used to make
key's unique. So you may store multiple unique data items within
the cache.
=head1 CONFIGURATION
The following items can be set by configuration:
cache_rehash wither to attempt a failover to another server
cache_expires the expiration of items within the cache
cache_servers which cache servers to use
cache_compress_threshold the threshold to start compression
The following reasonable defaults are being used for those items:
cache_rehash no
cache_expires 3600 seconds
cache_servers 127.0.0.1:11212
cache_compress_threshold 1000 bytes
Since this cache is being managed by Cache::Memcached, any changes to those
defaults should be consistent with that modules usage.
=head1 METHODS
=over 4
=item cache_init
This method will initialize the cache. It should be called only once within
the application.
$self->cache_init();
=item cache_inited
For internal use.
Dual use accessor for init flag. If cache_init has run this attribute
is 1, otherwise it's 0.
=item cache_namespace
This method will get/set the current namespace for cache operations.
$self->cache_namespace($namespace);
=item cache_handle
This method returns the handle for the underlining cache. You can use
this handle to manipulate the cache directly. Doing so will be highly
specific to the underling cache handler.
$handle = $self->cache_handle();
=item cache_purge
Equivalent to
$self->cache_handle();
This method is for other cache plugins which support a purge method.
=item cache_get
This method returns the data associated with the current namespace/key
combination.
$self->cache_namespace($namespace);
$data = $self->cache_get($key);
=item cache_set
This method stores the data associated with the current namespace/key
combination.
$self->cache_namespace($namespace);
$self->cache_set($key, $data);
=item cache_keys
This method is currently not available with memcached.
=item cache_clear
This method will clear the entire cache.
$self->cache_clear();
=item cache_del
This method removes the data associated with the current namespace/key
combination.
$self->cache_namespace($namespace);
$self->cache_del($key);
=item cache_expires
Retrieves the current expiration time for data items with thecache. The
expiration time can be changed for this module. It is adviseable to not do
so. Expiration time formats are highly specific to the underlining cache
handler.
$expiration = $self->cache_expires();
=back
=head1 SEE ALSO
Gantry
=head1 AUTHORS
Kevin L. Esteb <kesteb@wsipc.org>,
Tim Keefer <tim@timkeefer.com>
=head1 COPYRIGHT AND LICENSE
Copyright (C) 2007 Kevin L. Esteb
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself, either Perl version 5.8.6 or,
at your option, any later version of Perl 5 you may have available.
=cut