Initial commit of Caching Driver.
diff --git a/system/libraries/Cache/drivers/Cache_memcached.php b/system/libraries/Cache/drivers/Cache_memcached.php
new file mode 100644
index 0000000..adc7fbf
--- /dev/null
+++ b/system/libraries/Cache/drivers/Cache_memcached.php
@@ -0,0 +1,209 @@
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 4.3.2 or newer
+ *
+ * @package CodeIgniter
+ * @author ExpressionEngine Dev Team
+ * @copyright Copyright (c) 2006 - 2010 EllisLab, Inc.
+ * @license http://codeigniter.com/user_guide/license.html
+ * @link http://codeigniter.com
+ * @since Version 2.0
+ * @filesource
+ */
+
+// ------------------------------------------------------------------------
+
+/**
+ * CodeIgniter Memcached Caching Class
+ *
+ * @package CodeIgniter
+ * @subpackage Libraries
+ * @category Core
+ * @author ExpressionEngine Dev Team
+ * @link
+ */
+
+class Cache_memcached extends CI_Driver {
+
+ private $_memcached; // Holds the memcached object
+
+ protected $_memcache_conf = array(
+ 'default' => array(
+ 'default_host' => '127.0.0.1',
+ 'default_port' => 11211,
+ 'default_weight' => 1
+ )
+ );
+
+ // ------------------------------------------------------------------------
+
+ /**
+ * Fetch from cache
+ *
+ * @param mixed unique key id
+ * @return mixed data on success/false on failure
+ */
+ public function get($id)
+ {
+ $data = $this->_memcached->get($id);
+
+ return (is_array($data)) ? $data[0] : FALSE;
+ }
+
+ // ------------------------------------------------------------------------
+
+ /**
+ * Save
+ *
+ * @param string unique identifier
+ * @param mixed data being cached
+ * @param int time to live
+ * @return boolean true on success, false on failure
+ */
+ public function save($id, $data, $ttl = 60)
+ {
+ return $this->_memcached->add($id, array($data, time(), $ttl), $ttl);
+ }
+
+ // ------------------------------------------------------------------------
+
+ /**
+ * Delete from Cache
+ *
+ * @param mixed key to be deleted.
+ * @return boolean true on success, false on failure
+ */
+ public function delete($id)
+ {
+ return $this->_memcached->delete($id);
+ }
+
+ // ------------------------------------------------------------------------
+
+ /**
+ * Clean the Cache
+ *
+ * @return boolean false on failure/true on success
+ */
+ public function clean()
+ {
+ return $this->_memcached->flush();
+ }
+
+ // ------------------------------------------------------------------------
+
+ /**
+ * Cache Info
+ *
+ * @param null type not supported in memcached
+ * @return mixed array on success, false on failure
+ */
+ public function cache_info($type = NULL)
+ {
+ return $this->_memcached->getStats();
+ }
+
+ // ------------------------------------------------------------------------
+
+ /**
+ * Get Cache Metadata
+ *
+ * @param mixed key to get cache metadata on
+ * @return mixed FALSE on failure, array on success.
+ */
+ public function get_metadata($id)
+ {
+ $stored = $this->_memcached->get($id);
+
+ if (count($stored) !== 3)
+ {
+ return FALSE;
+ }
+
+ list($value, $time, $ttl) = $stored;
+
+ return array(
+ 'expire' => $time + $ttl,
+ 'mtime' => $time,
+ 'data' => $data
+ );
+ }
+
+ // ------------------------------------------------------------------------
+
+ /**
+ * Setup memcached.
+ */
+ private function _setup_memcached()
+ {
+ // Try to load memcached server info from the config file.
+ $CI =& get_instance();
+ if ($CI->config->load('memcached', TRUE, TRUE))
+ {
+ if (is_array($CI->config->config['memcached']))
+ {
+ $this->_memcache_conf = NULL;
+
+ foreach ($CI->config->config['memcached'] as $name => $conf)
+ {
+ $this->_memcache_conf[$name] = $conf;
+ }
+ }
+ }
+
+ $this->_memcached = new Memcached();
+
+ foreach ($this->_memcache_conf as $name => $cache_server)
+ {
+ if ( ! array_key_exists('hostname', $cache_server))
+ {
+ $cache_server['hostname'] = $this->_default_options['default_host'];
+ }
+
+ if ( ! array_key_exists('port', $cache_server))
+ {
+ $cache_server['port'] = $this->_default_options['default_port'];
+ }
+
+ if ( ! array_key_exists('weight', $cache_server))
+ {
+ $cache_server['weight'] = $this->_default_options['default_weight'];
+ }
+
+ $this->_memcached->addServer(
+ $cache_server['hostname'], $cache_server['port'], $cache_server['weight']
+ );
+ }
+ }
+
+ // ------------------------------------------------------------------------
+
+
+ /**
+ * Is supported
+ *
+ * Returns FALSE if memcached is not supported on the system.
+ * If it is, we setup the memcached object & return TRUE
+ */
+ public function is_supported()
+ {
+ if ( ! extension_loaded('memcached'))
+ {
+ log_message('error', 'The Memcached Extension must be loaded to use Memcached Cache.');
+
+ return FALSE;
+ }
+
+ $this->_setup_memcached();
+ return TRUE;
+ }
+
+ // ------------------------------------------------------------------------
+
+}
+// End Class
+
+/* End of file Cache_memcached.php */
+/* Location: ./system/libraries/Cache/drivers/Cache_memcached.php */
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