added memcache cache driver

lib/Doctrine/Cache/Memcache.php

+<?php
+/*
+ *  $Id$
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the LGPL. For more information, see
+ * <http://www.phpdoctrine.com>.
+ */
+Doctrine::autoload('Doctrine_Cache_Driver');
+/**
+ * Doctrine_Cache_Memcache
+ *
+ * @package     Doctrine
+ * @subpackage  Doctrine_Cache
+ * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
+ * @category    Object Relational Mapping
+ * @link        www.phpdoctrine.com
+ * @since       1.0
+ * @version     $Revision$
+ * @author      Konsta Vesterinen <kvesteri@cc.hut.fi>
+ */
+class Doctrine_Cache_Memcache extends Doctrine_Cache_Driver
+{
+    /**
+     * @var Memcache $_memcache     memcache object
+     */
+    private $_memcache = null;
+    /**
+     * constructor
+     * 
+     * @param array $options        associative array of cache driver options
+     */
+    public function __construct($options = array())
+    {      
+        if (!extension_loaded('memcache')) {
+            throw new Doctrine_Cache_Exception('In order to use Memcache driver, the memcache extension must be loaded.');
+        }
+        parent::__construct($options);
+
+        if (isset($options['servers'])) {
+            $value= $options['servers'];
+            if (isset($value['host'])) {
+                // in this case, $value seems to be a simple associative array (one server only)
+                $value = array(0 => $value); // let's transform it into a classical array of associative arrays
+            }
+            $this->setOption('servers', $value);
+        }
+        
+        $this->_memcache = new Memcache;
+
+        foreach ($this->_options['servers'] as $server) {
+            if ( ! array_key_exists('persistent', $server)) {
+                $server['persistent'] = true;
+            }
+            if ( ! array_key_exists('port', $server)) {
+                $server['port'] = 11211;
+            }
+            $this->_memcache->addServer($server['host'], $server['port'], $server['persistent']);
+        }
+    }
+    /**
+     * Test if a cache is available for the given id and (if yes) return it (false else)
+     *
+     * Note : return value is always "string" (unserialization is done by the core not by the backend)
+     * 
+     * @param string $id cache id
+     * @param boolean $testCacheValidity        if set to false, the cache validity won't be tested
+     * @return string cached datas (or false)
+     */
+    public function fetch($id, $testCacheValidity = true) 
+    {
+        $tmp = $this->_memcache->get($id);
+
+        if (is_array($tmp)) {
+            return $tmp[0];
+        }
+
+        return false;
+    }
+    /**
+     * Test if a cache is available or not (for the given id)
+     *
+     * @param string $id cache id
+     * @return mixed false (a cache is not available) or "last modified" timestamp (int) of the available cache record
+     */
+    public function contains($id) 
+    {
+        return (bool) $this->_memcache->get($id);
+    }
+    /**
+     * Save some string datas into a cache record
+     *
+     * Note : $data is always saved as a string
+     *
+     * @param string $data      data to cache
+     * @param string $id        cache id
+     * @param int $lifeTime     if != false, set a specific lifetime for this cache record (null => infinite lifeTime)
+     * @return boolean true if no problem
+     */
+    public function save($data, $id, $lifeTime = false)
+    {
+        $lifeTime = $this->getLifeTime($specificLifeTime);
+
+        if ($this->_options['compression']) {
+            $flag = MEMCACHE_COMPRESSED;
+        } else {
+            $flag = 0;
+        }
+
+        $result = $this->_memcache->set($id, array($data, time()), $flag, $lifeTime);
+    }
+    /**
+     * Remove a cache record
+     * 
+     * @param string $id cache id
+     * @return boolean true if no problem
+     */
+    public function delete($id) 
+    {
+        return $this->_memcache->delete($id);
+    }
+}