#
# 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 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 3 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.
+# 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.
+# You should have received a copy of the GNU General Public License
+# along with Koha; if not, see <http://www.gnu.org/licenses>.
=head1 NAME
use Koha::Cache;
my $cache = Koha::Cache->new({cache_type => $cache_type, %params});
+ # see also Koha::Caches->get_instance;
+
=head1 DESCRIPTION
Koha caching routines. This class provides two interfaces for cache access.
-The first, traditional interface provides the following functions:
+The first, traditional OO interface provides the following functions:
=head1 FUNCTIONS
use strict;
use warnings;
-use Carp;
-use Module::Load::Conditional qw(can_load);
+use Carp qw( croak );
+use Module::Load::Conditional qw( can_load );
+use Sereal::Encoder;
+use Sereal::Decoder;
+
+use C4::Context;
use Koha::Cache::Object;
+use Koha::Config;
use base qw(Class::Accessor);
__PACKAGE__->mk_ro_accessors(
- qw( cache memcached_cache fastmmap_cache memory_cache ));
+ qw( cache memcached_cache ));
+
+our %L1_cache;
+our $L1_encoder = Sereal::Encoder->new;
+our $L1_decoder = Sereal::Decoder->new;
=head2 new
=cut
sub new {
- my ( $class, $self ) = @_;
+ my ( $class, $self, $params ) = @_;
$self->{'default_type'} =
$self->{cache_type}
- || $ENV{CACHING_SYSTEM}
+ || $ENV{CACHING_SYSTEM} # DELME What about this?
|| 'memcached';
- $ENV{DEBUG} && carp "Default caching system: $self->{'default_type'}";
+ my $subnamespace = $params->{subnamespace} // '';
$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'};
- }
+ # Should we continue to support MEMCACHED ENV vars?
+ $self->{'namespace'} ||= $ENV{MEMCACHED_NAMESPACE};
+ my @servers = split /,/, $ENV{MEMCACHED_SERVERS} || '';
+ $self->{namespace} ||= C4::Context->config('memcached_namespace') || 'koha';
+ @servers = split /,/, C4::Context->config('memcached_servers') // ''
+ unless @servers;
+ $self->{namespace} .= ":$subnamespace:";
+
+ if ( $self->{'default_type'} eq 'memcached'
+ && can_load( modules => { 'Cache::Memcached::Fast::Safe' => undef } )
+ && _initialize_memcached($self, @servers)
+ && 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'};
- $self->{'memcached_cache'} = Cache::Memcached::Fast->new(
+ my ($self, @servers) = @_;
+
+ return unless @servers;
+
+ # Cache::Memcached::Fast::Safe doesn't allow a default expire time to be set
+ # so we force it on setting.
+ my $memcached = Cache::Memcached::Fast::Safe->new(
{
servers => \@servers,
compress_threshold => 10_000,
namespace => $self->{'namespace'},
+ utf8 => 1,
}
);
- 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'}
- );
+ # Ensure we can actually talk to the memcached server
+ my $ismemcached = $memcached->set('ismemcached','1');
+ unless ($ismemcached) {
+ warn "\nConnection to the memcached servers '@servers' failed. Are the unix socket permissions set properly? Is the host reachable?\nIf you ignore this warning, you will face performance issues\n";
+ return $self;
+ }
+ $self->{'memcached_cache'} = $memcached;
return $self;
}
=head2 is_cache_active
-Routine that checks whether or not a caching system has been selected. This is
-not an instance method.
+Routine that checks whether or not a default caching method is active on this
+object.
=cut
sub is_cache_active {
- return $ENV{CACHING_SYSTEM} ? '1' : '';
+ my $self = shift;
+ return $self->{'cache'} ? 1 : 0;
}
=head2 set_in_cache
- $cache->set_in_cache($key, $value, [$expiry]);
+ $cache->set_in_cache($key, $value, [$options]);
+
+Save a value to the specified key in the cache. A hashref of options may be
+specified.
+
+The possible options are:
+
+=over
+
+=item expiry
+
+Expiry time of this cached entry in seconds.
-Save a value to the specified key in the default cache, optionally with a
-particular expiry.
+=item cache
+
+The cache object to use if you want to provide your own. It should be an
+instance of C<Cache::*> and follow the same interface as L<Cache::Memcache>.
+
+=back
=cut
sub set_in_cache {
- my ( $self, $key, $value, $expiry, $cache ) = @_;
- $cache ||= 'cache';
+ my ( $self, $key, $value, $options ) = @_;
+
+ my $unsafe = $options->{unsafe} || 0;
+
+ # the key mustn't contain whitespace (or control characters) for memcache
+ # but shouldn't be any harm in applying it globally.
+ $key =~ s/[\x00-\x20]/_/g;
+
+ my $cache = $options->{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 );
+ my $expiry = $options->{expiry};
+ $expiry //= $self->{timeout};
+ my $set_sub = $self->{ref($self->{$cache}) . "_set"};
+
+ my $flag = '-CF0'; # 0: scalar, 1: frozen data structure
+ if (ref($value)) {
+ # Set in L1 cache as a data structure
+ # We only save the frozen form: we do want to save $value in L1
+ # directly in order to protect it. And thawing now may not be
+ # needed, so improves performance.
+ $value = $L1_encoder->encode($value);
+ $L1_cache{$self->{namespace}}{$key}->{frozen} = $value;
+ $flag = '-CF1';
+ } else {
+ # Set in L1 cache as a scalar; exit if we are caching an undef
+ $L1_cache{$self->{namespace}}{$key} = $value;
+ return if !defined $value;
+ }
+
+ $value .= $flag;
+ # We consider an expiry of 0 to be infinite
+ if ( $expiry ) {
+ return $set_sub
+ ? $set_sub->( $key, $value, $expiry )
+ : $self->{$cache}->set( $key, $value, $expiry );
}
else {
- return $self->{$cache}->set( $key, $value );
+ return $set_sub
+ ? $set_sub->( $key, $value )
+ : $self->{$cache}->set( $key, $value );
}
}
=head2 get_from_cache
- my $value = $cache->get_from_cache($key);
+ my $value = $cache->get_from_cache($key, [ $options ]);
+
+Retrieve the value stored under the specified key in the cache.
+
+The possible options are:
+
+=over
+
+=item unsafe
+
+If set, this will avoid performing a deep copy of the item. This
+means that it won't be safe if something later modifies the result of the
+function. It should be used with caution, and could save processing time
+in some situations where is safe to use it. Make sure you know what you are doing!
+
+=item cache
-Retrieve the value stored under the specified key in the default cache.
+The cache object to use if you want to provide your own. It should be an
+instance of C<Cache::*> and follow the same interface as L<Cache::Memcache>.
+
+=back
=cut
sub get_from_cache {
- my ( $self, $key, $cache ) = @_;
- $cache ||= 'cache';
+ my ( $self, $key, $options ) = @_;
+ my $cache = $options->{cache} || 'cache';
+ my $unsafe = $options->{unsafe} || 0;
+ $key =~ s/[\x00-\x20]/_/g;
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);
+
+ # Return L1 cache value if exists
+ if ( exists $L1_cache{$self->{namespace}}{$key} ) {
+ if (ref($L1_cache{$self->{namespace}}{$key})) {
+ if ($unsafe) {
+ # ONLY use thawed for unsafe calls !!!
+ $L1_cache{$self->{namespace}}{$key}->{thawed} ||= $L1_decoder->decode($L1_cache{$self->{namespace}}{$key}->{frozen});
+ return $L1_cache{$self->{namespace}}{$key}->{thawed};
+ } else {
+ return $L1_decoder->decode($L1_cache{$self->{namespace}}{$key}->{frozen});
+ }
+ } else {
+ # No need to thaw if it's a scalar
+ return $L1_cache{$self->{namespace}}{$key};
+ }
+ }
+
+ my $get_sub = $self->{ref($self->{$cache}) . "_get"};
+ my $L2_value = $get_sub ? $get_sub->($key) : $self->{$cache}->get($key);
+
+ return if ref($L2_value);
+ return unless (defined($L2_value) && length($L2_value) >= 4);
+
+ my $flag = substr($L2_value, -4, 4, '');
+ if ($flag eq '-CF0') {
+ # it's a scalar
+ $L1_cache{$self->{namespace}}{$key} = $L2_value;
+ return $L2_value;
+ } elsif ($flag eq '-CF1') {
+ # it's a frozen data structure
+ my $thawed;
+ eval { $thawed = $L1_decoder->decode($L2_value); };
+ return if $@;
+ $L1_cache{$self->{namespace}}{$key}->{frozen} = $L2_value;
+ # ONLY save thawed for unsafe calls !!!
+ $L1_cache{$self->{namespace}}{$key}->{thawed} = $thawed if $unsafe;
+ return $thawed;
+ }
+
+ # Unknown value / data type returned from L2 cache
+ return;
}
=head2 clear_from_cache
sub clear_from_cache {
my ( $self, $key, $cache ) = @_;
+ $key =~ s/[\x00-\x20]/_/g;
$cache ||= 'cache';
croak "No key" unless $key;
return unless ( $self->{$cache} && ref( $self->{$cache} ) =~ m/^Cache::/ );
+
+ # Clear from L1 cache
+ delete $L1_cache{$self->{namespace}}{$key};
+
return $self->{$cache}->delete($key)
- if ( ref( $self->{$cache} ) eq 'Cache::Memcached::Fast' );
+ if ( ref( $self->{$cache} ) =~ m'^Cache::Memcached' );
return $self->{$cache}->remove($key);
}
my ( $self, $cache ) = shift;
$cache ||= 'cache';
return unless ( $self->{$cache} && ref( $self->{$cache} ) =~ m/^Cache::/ );
+
+ $self->flush_L1_cache();
+
return $self->{$cache}->flush_all()
- if ( ref( $self->{$cache} ) eq 'Cache::Memcached::Fast' );
+ if ( ref( $self->{$cache} ) =~ m'^Cache::Memcached' );
return $self->{$cache}->clear();
}
+sub flush_L1_cache {
+ my( $self ) = @_;
+ delete $L1_cache{$self->{namespace}};
+}
+
=head1 TIED INTERFACE
Koha::Cache also provides a tied interface which enables users to provide a
$args->{'timeout'} = '600' unless defined( $args->{'timeout'} );
$args->{'inprocess'} = '0' unless defined( $args->{'inprocess'} );
- unless ( lc( $args->{'cache_type'} ) eq 'null' ) {
+ unless ( $args->{cache_type} and lc( $args->{cache_type} ) eq 'null' ) {
$args->{'cache'} = $self;
$args->{'cache_type'} ||= $ENV{'CACHING_SYSTEM'};
}
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