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lib/Cache/Elasticache/Memcache.pm  view on Meta::CPAN

package Cache::Elasticache::Memcache;

use strict;
use warnings;

=pod

=for HTML <a href="https://travis-ci.org/zebardy/cache-elasticache-memcache"><img src="https://travis-ci.org/zebardy/cache-elasticache-memcache.svg?branch=master"></a>

=head1 NAME

Cache::Elasticache::Memcache - A wrapper for L<Cache::Memacached::Fast> with support for AWS's auto reconfiguration mechanism

=head1 SYNOPSIS

    use Cache::Elasticache::Memcache;

    my $memd = new Cache::Elasticache::Memcache->new({
        config_endpoint => 'foo.bar',
        update_period => 180,
        # All other options are passed on to Cache::Memcached::Fast
        ...
    });

    # Will update the server list from the configuration endpoint
    $memd->updateServers();

    # Will update the serverlist from the configuration endpoint if the time since
    # the last time the server list was checked is greater than the update period
    # specified when the $memd object was created.
    $memd->checkServers();

    # Class method to retrieve a server list from a configuration endpoint.
    Cache::Elasticache::Memcache->getServersFromEndpoint('foo.bar');

    # All other supported methods are handled by Cache::Memcached::Fast

    # N.B. This library is currently under development

=head1 DESCRIPTION

A wrapper for L<Cache::Memacached::Fast> with support for AWS's auto reconfiguration mechanism. It makes use of an AWS elasticache memcached cluster's configuration endpoint to discover the memcache servers in the cluster and periodically check the c...

=head1 UNDER DEVELOPMENT DISCALIMER

N.B. This module is still under development. It should work, but things may change under the hood. I plan to imporove the resiliance with better timeout handling of communication when updating the server list. I'm toying with the idea of making the s...

=cut

use Carp;
use IO::Socket::IP;
use IO::Socket::Timeout;
use Cache::Memcached::Fast;
use Try::Tiny;
use Scalar::Util qw(blessed);

our $VERSION = '0.0.5';

=pod

=head1 CONSTRUCTOR

    Cache::Elasticache::Memcache->new({
        config_endpoint => 'foo.bar',
        update_period => 180,
        ...
    })

=head2 Constructor parameters

=over

=item config_endpoint

AWS elasticache memcached cluster config endpoint location

=item update_period

The minimum period (in seconds) to wait between updating the server list. Defaults to 180 seconds

=back

=cut

sub new {
    my $class = shift;
    my ($conf) = @_;
    my $self = bless {}, $class;

    my $args = (@_ == 1) ? shift : { @_ };  # hashref-ify args

    croak "config_endpoint must be speccified" if (!defined $args->{'config_endpoint'});
    croak "servers is not a valid constructors parameter" if (defined $args->{'servers'});

    $self->{'config_endpoint'} = delete @{$args}{'config_endpoint'};

    $args->{servers} = $self->getServersFromEndpoint($self->{'config_endpoint'}) if(defined $self->{'config_endpoint'});
    $self->{_last_update} = time;

    $self->{update_period} = exists $args->{update_period} ? $args->{update_period} : 180;

    $self->{'_args'} = $args;
    $self->{_memd} = Cache::Memcached::Fast->new($args);
    $self->{servers} = $args->{servers};

    return $self;
}

=pod

=head1 METHODS

=over