<?php
/* -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
# ***** BEGIN LICENSE BLOCK *****
# This file is part of Plume Framework, a simple PHP Application Framework.
# Copyright (C) 2001-2007 Loic d'Anterroches and contributors.
#
# Plume Framework is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
#
# Plume Framework 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 Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#
# ***** END LICENSE BLOCK ***** */

/**
 * Memcached based cache.
 *
 * A special 'cache_memcached_keyprefix' can be set to use one
 * memcached for different applications and avoid conflict.
 *
 * Example of configuration:
 *
 * <pre>
 * $cfg['cache_engine'] = 'Pluf_Cache_Memcached';
 * $cfg['cache_timeout'] = 300;
 * $cfg['cache_memcached_keyprefix'] = 'uniqueforapp';
 * $cfg['cache_memcached_server'] = 'localhost';
 * $cfg['cache_memcached_port'] = 11211;
 * $cfg['cache_memcached_compress'] = 0; (or MEMCACHE_COMPRESSED)
 * </pre>
 */
class Pluf_Cache_Memcached extends Pluf_Cache
{
    private $memcache = null;
    private $keyprefix = '';

    public function __construct()
    {
        $this->memcache = memcache_connect(Pluf::f('cache_memcached_server', 'localhost'),
                                           Pluf::f('cache_memcached_port', 11211));
        if (false === $this->memcache) {
            $this->memcache = null;
        }
        $this->keyprefix = Pluf::f('cache_memcached_keyprefix', '');
    }

    /**
     * Set a value in the cache.
     *
     * @param string Key to store the information
     * @param mixed Value to store
     * @param int Timeout in seconds (null)
     * @return bool Success
     */
    public function set($key, $value, $timeout=null)
    {
        if ($this->memcache) {
            if ($timeout == null) $timeout = Pluf::f('cache_timeout', 300);
            $this->memcache->set($this->keyprefix.$key, serialize($value), 
                                 Pluf::f('cache_memcached_compress', 0), 
                                 $timeout);
        }
    }

    /**
     * Get value from the cache.
     *
     * @param string Key to get the information
     * @param mixed Default value to return if cache miss (null)
     * @param mixed Stored value or default
     */
    public function get($key, $default=null)
    {
        if ($this->memcache) {
            $val = $this->memcache->get($this->keyprefix.$key);
            if (false === $val) {
                return $default;
            } else {
                return unserialize($val);
            }
        } else {
            return $default;
        }
    }
}