397 lines
10 KiB
Perl
397 lines
10 KiB
Perl
package Koha::Cache;
|
|
|
|
# Copyright 2009 Chris Cormack and The Koha Dev Team
|
|
# Parts copyright 2012-2013 C & P Bibliography Services
|
|
#
|
|
# This file is part of Koha.
|
|
#
|
|
# Koha is free software; you can redistribute it and/or modify it under the
|
|
# terms of the GNU General Public License as published by the Free Software
|
|
# Foundation; either version 2 of the License, or (at your option) any later
|
|
# version.
|
|
#
|
|
# Koha is distributed in the hope that it will be useful, but WITHOUT ANY
|
|
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
|
|
# A PARTICULAR PURPOSE. See the GNU General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU General Public License along
|
|
# with Koha; if not, write to the Free Software Foundation, Inc.,
|
|
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
|
|
=head1 NAME
|
|
|
|
Koha::Cache - Handling caching of html and Objects for Koha
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
use Koha::Cache;
|
|
my $cache = Koha::Cache->new({cache_type => $cache_type, %params});
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
Koha caching routines. This class provides two interfaces for cache access.
|
|
The first, traditional interface provides the following functions:
|
|
|
|
=head1 FUNCTIONS
|
|
|
|
=cut
|
|
|
|
use strict;
|
|
use warnings;
|
|
use Carp;
|
|
use Module::Load::Conditional qw(can_load);
|
|
use Koha::Cache::Object;
|
|
|
|
use base qw(Class::Accessor);
|
|
|
|
__PACKAGE__->mk_ro_accessors(
|
|
qw( cache memcached_cache fastmmap_cache memory_cache ));
|
|
|
|
=head2 new
|
|
|
|
Create a new Koha::Cache object. This is required for all cache-related functionality.
|
|
|
|
=cut
|
|
|
|
sub new {
|
|
my ( $class, $self ) = @_;
|
|
$self->{'default_type'} =
|
|
$self->{cache_type}
|
|
|| $ENV{CACHING_SYSTEM}
|
|
|| 'memcached';
|
|
|
|
$ENV{DEBUG} && carp "Default caching system: $self->{'default_type'}";
|
|
|
|
$self->{'timeout'} ||= 0;
|
|
$self->{'namespace'} ||= $ENV{MEMCACHED_NAMESPACE} || 'koha';
|
|
|
|
if ( can_load( modules => { 'Cache::Memcached::Fast' => undef } ) ) {
|
|
_initialize_memcached($self);
|
|
if ( $self->{'default_type'} eq 'memcached'
|
|
&& defined( $self->{'memcached_cache'} ) )
|
|
{
|
|
$self->{'cache'} = $self->{'memcached_cache'};
|
|
}
|
|
}
|
|
|
|
if ( can_load( modules => { 'Cache::FastMmap' => undef } ) ) {
|
|
_initialize_fastmmap($self);
|
|
if ( $self->{'default_type'} eq 'fastmmap'
|
|
&& defined( $self->{'fastmmap_cache'} ) )
|
|
{
|
|
$self->{'cache'} = $self->{'fastmmap_cache'};
|
|
}
|
|
}
|
|
|
|
if ( can_load( modules => { 'Cache::Memory' => undef } ) ) {
|
|
_initialize_memory($self);
|
|
if ( $self->{'default_type'} eq 'memory'
|
|
&& defined( $self->{'memory_cache'} ) )
|
|
{
|
|
$self->{'cache'} = $self->{'memory_cache'};
|
|
}
|
|
}
|
|
|
|
# NOTE: The following five lines could be uncommented if we wanted to
|
|
# fall back to any functioning cache. Commented out since this would
|
|
# represent a change in behavior.
|
|
#
|
|
#unless (defined($self->{'cache'})) {
|
|
# foreach my $cachemember (qw(memory_cache fastmmap_cache memcached_cache)) {
|
|
# $self->{'cache'} = $self->{$cachemember} if (defined($self->{$cachemember}));
|
|
# }
|
|
#}
|
|
|
|
return
|
|
bless $self,
|
|
$class;
|
|
}
|
|
|
|
sub _initialize_memcached {
|
|
my ($self) = @_;
|
|
my @servers =
|
|
split /,/, $self->{'cache_servers'}
|
|
? $self->{'cache_servers'}
|
|
: $ENV{MEMCACHED_SERVERS};
|
|
|
|
$ENV{DEBUG}
|
|
&& carp "Memcached server settings: "
|
|
. join( ', ', @servers )
|
|
. " with "
|
|
. $self->{'namespace'};
|
|
$self->{'memcached_cache'} = Cache::Memcached::Fast->new(
|
|
{
|
|
servers => \@servers,
|
|
compress_threshold => 10_000,
|
|
namespace => $self->{'namespace'},
|
|
}
|
|
);
|
|
return $self;
|
|
}
|
|
|
|
sub _initialize_fastmmap {
|
|
my ($self) = @_;
|
|
|
|
$self->{'fastmmap_cache'} = Cache::FastMmap->new(
|
|
'share_file' => "/tmp/sharefile-koha-$self->{'namespace'}",
|
|
'expire_time' => $self->{'timeout'},
|
|
'unlink_on_exit' => 0,
|
|
);
|
|
return $self;
|
|
}
|
|
|
|
sub _initialize_memory {
|
|
my ($self) = @_;
|
|
|
|
$self->{'memory_cache'} = Cache::Memory->new(
|
|
'namespace' => $self->{'namespace'},
|
|
'default_expires' => $self->{'timeout'}
|
|
);
|
|
return $self;
|
|
}
|
|
|
|
=head2 is_cache_active
|
|
|
|
Routine that checks whether or not a caching system has been selected. This is
|
|
not an instance method.
|
|
|
|
=cut
|
|
|
|
sub is_cache_active {
|
|
return $ENV{CACHING_SYSTEM} ? '1' : '';
|
|
}
|
|
|
|
=head2 set_in_cache
|
|
|
|
$cache->set_in_cache($key, $value, [$expiry]);
|
|
|
|
Save a value to the specified key in the default cache, optionally with a
|
|
particular expiry.
|
|
|
|
=cut
|
|
|
|
sub set_in_cache {
|
|
my ( $self, $key, $value, $expiry, $cache ) = @_;
|
|
$cache ||= 'cache';
|
|
croak "No key" unless $key;
|
|
$ENV{DEBUG} && carp "set_in_cache for $key";
|
|
|
|
return unless ( $self->{$cache} && ref( $self->{$cache} ) =~ m/^Cache::/ );
|
|
if ( defined $expiry ) {
|
|
if ( ref( $self->{$cache} ) eq 'Cache::Memory' ) {
|
|
$expiry = "$expiry sec";
|
|
}
|
|
return $self->{$cache}->set( $key, $value, $expiry );
|
|
}
|
|
else {
|
|
return $self->{$cache}->set( $key, $value );
|
|
}
|
|
}
|
|
|
|
=head2 get_from_cache
|
|
|
|
my $value = $cache->get_from_cache($key);
|
|
|
|
Retrieve the value stored under the specified key in the default cache.
|
|
|
|
=cut
|
|
|
|
sub get_from_cache {
|
|
my ( $self, $key, $cache ) = @_;
|
|
$cache ||= 'cache';
|
|
croak "No key" unless $key;
|
|
$ENV{DEBUG} && carp "get_from_cache for $key";
|
|
return unless ( $self->{$cache} && ref( $self->{$cache} ) =~ m/^Cache::/ );
|
|
return $self->{$cache}->get($key);
|
|
}
|
|
|
|
=head2 clear_from_cache
|
|
|
|
$cache->clear_from_cache($key);
|
|
|
|
Remove the value identified by the specified key from the default cache.
|
|
|
|
=cut
|
|
|
|
sub clear_from_cache {
|
|
my ( $self, $key, $cache ) = @_;
|
|
$cache ||= 'cache';
|
|
croak "No key" unless $key;
|
|
return unless ( $self->{$cache} && ref( $self->{$cache} ) =~ m/^Cache::/ );
|
|
return $self->{$cache}->delete($key)
|
|
if ( ref( $self->{$cache} ) eq 'Cache::Memcached::Fast' );
|
|
return $self->{$cache}->remove($key);
|
|
}
|
|
|
|
=head2 flush_all
|
|
|
|
$cache->flush_all();
|
|
|
|
Clear the entire default cache.
|
|
|
|
=cut
|
|
|
|
sub flush_all {
|
|
my ( $self, $cache ) = shift;
|
|
$cache ||= 'cache';
|
|
return unless ( $self->{$cache} && ref( $self->{$cache} ) =~ m/^Cache::/ );
|
|
return $self->{$cache}->flush_all()
|
|
if ( ref( $self->{$cache} ) eq 'Cache::Memcached::Fast' );
|
|
return $self->{$cache}->clear();
|
|
}
|
|
|
|
=head1 TIED INTERFACE
|
|
|
|
Koha::Cache also provides a tied interface which enables users to provide a
|
|
constructor closure and (after creation) treat cached data like normal reference
|
|
variables and rely on the cache Just Working and getting updated when it
|
|
expires, etc.
|
|
|
|
my $cache = Koha::Cache->new();
|
|
my $data = 'whatever';
|
|
my $scalar = Koha::Cache->create_scalar(
|
|
{
|
|
'key' => 'whatever',
|
|
'timeout' => 2,
|
|
'constructor' => sub { return $data; },
|
|
}
|
|
);
|
|
print "$$scalar\n"; # Prints "whatever"
|
|
$data = 'somethingelse';
|
|
print "$$scalar\n"; # Prints "whatever" because it is cached
|
|
sleep 2; # Wait until the cache entry has expired
|
|
print "$$scalar\n"; # Prints "somethingelse"
|
|
|
|
my $hash = Koha::Cache->create_hash(
|
|
{
|
|
'key' => 'whatever',
|
|
'timeout' => 2,
|
|
'constructor' => sub { return $data; },
|
|
}
|
|
);
|
|
print "$$variable\n"; # Prints "whatever"
|
|
|
|
The gotcha with this interface, of course, is that the variable returned by
|
|
create_scalar and create_hash is a I<reference> to a tied variable and not a
|
|
tied variable itself.
|
|
|
|
The tied variable is configured by means of a hashref passed in to the
|
|
create_scalar and create_hash methods. The following parameters are supported:
|
|
|
|
=over
|
|
|
|
=item I<key>
|
|
|
|
Required. The key to use for identifying the variable in the cache.
|
|
|
|
=item I<constructor>
|
|
|
|
Required. A closure (or reference to a function) that will return the value that
|
|
needs to be stored in the cache.
|
|
|
|
=item I<preload>
|
|
|
|
Optional. A closure (or reference to a function) that gets run to initialize
|
|
the cache when creating the tied variable.
|
|
|
|
=item I<arguments>
|
|
|
|
Optional. Array reference with the arguments that should be passed to the
|
|
constructor function.
|
|
|
|
=item I<timeout>
|
|
|
|
Optional. The cache timeout in seconds for the variable. Defaults to 600
|
|
(ten minutes).
|
|
|
|
=item I<cache_type>
|
|
|
|
Optional. Which type of cache to use for the variable. Defaults to whatever is
|
|
set in the environment variable CACHING_SYSTEM. If set to 'null', disables
|
|
caching for the tied variable.
|
|
|
|
=item I<allowupdate>
|
|
|
|
Optional. Boolean flag to allow the variable to be updated directly. When this
|
|
is set and the variable is used as an l-value, the cache will be updated
|
|
immediately with the new value. Using this is probably a bad idea on a
|
|
multi-threaded system. When I<allowupdate> is not set to true, using the
|
|
tied variable as an l-value will have no effect.
|
|
|
|
=item I<destructor>
|
|
|
|
Optional. A closure (or reference to a function) that should be called when the
|
|
tied variable is destroyed.
|
|
|
|
=item I<unset>
|
|
|
|
Optional. Boolean flag to tell the object to remove the variable from the cache
|
|
when it is destroyed or goes out of scope.
|
|
|
|
=item I<inprocess>
|
|
|
|
Optional. Boolean flag to tell the object not to refresh the variable from the
|
|
cache every time the value is desired, but rather only when the I<local> copy
|
|
of the variable is older than the timeout.
|
|
|
|
=back
|
|
|
|
=head2 create_scalar
|
|
|
|
my $scalar = Koha::Cache->create_scalar(\%params);
|
|
|
|
Create scalar tied to the cache.
|
|
|
|
=cut
|
|
|
|
sub create_scalar {
|
|
my ( $self, $args ) = @_;
|
|
|
|
$self->_set_tied_defaults($args);
|
|
|
|
tie my $scalar, 'Koha::Cache::Object', $args;
|
|
return \$scalar;
|
|
}
|
|
|
|
sub create_hash {
|
|
my ( $self, $args ) = @_;
|
|
|
|
$self->_set_tied_defaults($args);
|
|
|
|
tie my %hash, 'Koha::Cache::Object', $args;
|
|
return \%hash;
|
|
}
|
|
|
|
sub _set_tied_defaults {
|
|
my ( $self, $args ) = @_;
|
|
|
|
$args->{'timeout'} = '600' unless defined( $args->{'timeout'} );
|
|
$args->{'inprocess'} = '0' unless defined( $args->{'inprocess'} );
|
|
unless ( lc( $args->{'cache_type'} ) eq 'null' ) {
|
|
$args->{'cache'} = $self;
|
|
$args->{'cache_type'} ||= $ENV{'CACHING_SYSTEM'};
|
|
}
|
|
|
|
return $args;
|
|
}
|
|
|
|
=head1 EXPORT
|
|
|
|
None by default.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
Koha::Cache::Object
|
|
|
|
=head1 AUTHOR
|
|
|
|
Chris Cormack, E<lt>chris@bigballofwax.co.nzE<gt>
|
|
Paul Poulain, E<lt>paul.poulain@biblibre.comE<gt>
|
|
Jared Camins-Esakov, E<lt>jcamins@cpbibliography.comE<gt>
|
|
|
|
=cut
|
|
|
|
1;
|
|
|
|
__END__
|