package Gantry::Plugins::Cache::Storable;
use strict;
use warnings;
use Gantry;
use Gantry::Plugins::Cache;
use Storable qw(store nstore_fd fd_retrieve retrieve freeze thaw dclone);
use base 'Exporter';
our $VERSION = '0.01';
our @EXPORT = qw(
cache_clear
cache_del
cache_get
cache_set
cache_keys
cache_init
cache_purge
cache_handle
cache_inited
cache_expires
cache_namespace
cache_filename
);
sub cache_init {
my ($gobj) = @_;
#my $num_pages = $gobj->fish_config('cache_pages') || '256';
#my $page_size = $gobj->fish_config('cache_pagesize') || '256k';
#my $expire_time = $gobj->fish_config('cache_expires') || '1h';
my $share_file = $gobj->fish_config('cache_filename')
|| '/tmp/gantry.storable.cache';
$gobj->cache_filename( $share_file );
$gobj->cache_inited(1);
}
sub cache_inited {
my ($gobj, $p) = @_;
$$gobj{__CACHE_INITED__} = $p if defined $p;
return($$gobj{__CACHE_INITED__});
}
sub cache_filename {
my ($gobj, $p) = @_;
$$gobj{__CACHE_FILENAME__} = $p if defined $p;
return($$gobj{__CACHE_FILENAME__});
}
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 $namespace = $gobj->cache_namespace() || '';
my $skey = $namespace . ':' . $key;
my $file = $gobj->cache_filename;
if ( -e $file ) {
open( CACHE, $file ) or die "$!";
my $serialized = fd_retrieve( \*CACHE ) or die "retrieve error $!";
close( CACHE );
my $storable = thaw( $$serialized );
if ( defined $storable->{$skey} ) {
return( $storable->{$skey} );
}
else {
return;
}
}
}
sub cache_set {
my ($gobj, $key, $val) = @_;
my $namespace = $gobj->cache_namespace() || '';
my $skey = $namespace . ':' . $key;
my $file = $gobj->cache_filename;
my $serialized;
if ( ! -e $file ) {
my $storable = {
$skey => $val
};
$serialized = freeze( $storable );
}
else {
my $tmp_serialized = retrieve( $file ) or die "retrieve error $!";
my $storable = thaw( $$tmp_serialized );
$storable->{$skey} = $val;
$serialized = freeze( $storable );
}
open( CACHE, ">", $file ) or die "$!";
nstore_fd( \$serialized, \*CACHE ) or die "Can't store $key!\n";
close( CACHE );
}
sub cache_clear {
my($gobj) = @_;
my $file = $gobj->cache_filename();
if ( -e $file ) {
unlink( $file );
}
}
sub cache_keys {
my($gobj ) = @_;
my $file = $gobj->cache_filename();
my $namespace = $gobj->cache_namespace() || '';
my @keys_new;
if ( -e $file ) {
my $tmp_serialized = retrieve( $file ) or die "retrieve error $!";
my $storable = thaw( $$tmp_serialized );
foreach my $k ( keys %{ $storable } ) {
$k =~ s/^$namespace\://;
push( @keys_new, $k );
}
}
return \@keys_new;
}
sub cache_del {
my ($gobj, $key) = @_;
my $namespace = $gobj->cache_namespace() || '';
my $skey = $namespace . ':' . $key;
my $file = $gobj->cache_filename();
if ( -e $file ) {
my $tmp_serialized = retrieve( $file ) or die "retrieve error $!";
my $storable = thaw( $$tmp_serialized );
delete( $storable->{$skey} );
my $serialized = freeze( $storable );
open( CACHE, ">", $file ) or die "$!";
nstore_fd( \$serialized, \*CACHE ) or die "Can't store $key!\n";
close( CACHE );
}
}
sub cache_purge {
my ($gobj) = @_;
return;
}
1;
__END__
=head1 NAME
Gantry::Plugins::Cache::Storable - 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 Storable module to store that data.
<Perl>
# ...
use MyApp qw{ -Engine=CGI -TemplateEngine=TT Cache::Storable };
</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_pages the number of pages within the cache
cache_pagesize the sixe of those pages
cache_expires the expiration of items within the cache
cache_filename the cache filename
The following reasonable defaults are being used for those items:
cache_pages 256
cache_pagesize 256k
cache_expires 1h
cache_filename /tmp/gantry.cache
Since this cache is being managed by Cache::FastMmap, any changes to those
defaults should be consistent with that modules usage. Also note that
memory consumption may seem excessive. This may cause problems on your
system, so the Cache::FastMmap man pages will explain how to deal with
those issue.
=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_filename
Dual use accessor for the name of the disk file which holds the cache.
Defaults to '/tmp/gantry.storable.cache'.
=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
Useless here. 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 returns an arry reference of cache keys.
my $arrayref = $self->cache_keys();
=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 within the cache. The
expiration time is set when the cache is initially initialize. So setting
it will not change anything. Expiration time formats are highly specific to
the underlining cache handler.
$expiration = $self->cache_expires();
=back
=head1 SEE ALSO
Gantry
=head1 AUTHOR
Tim Keefer <tim@timkeefer.com>
=head1 COPYRIGHT AND LICENSE
Copyright (C) 2007 Tim Keefer
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