system/libraries/Cache/drivers/Cache_memcached.php

   1 <?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
   2 /**
   3  * CodeIgniter
   4  *
   5  * An open source application development framework for PHP 4.3.2 or newer
   6  *
   7  * @package             CodeIgniter
   8  * @author              ExpressionEngine Dev Team
   9  * @copyright   Copyright (c) 2006 - 2011 EllisLab, Inc.
  10  * @license             http://codeigniter.com/user_guide/license.html
  11  * @link                http://codeigniter.com
  12  * @since               Version 2.0
  13  * @filesource
  14  */
  15
  16 // ------------------------------------------------------------------------
  17
  18 /**
  19  * CodeIgniter Memcached Caching Class
  20  *
  21  * @package             CodeIgniter
  22  * @subpackage  Libraries
  23  * @category    Core
  24  * @author              ExpressionEngine Dev Team
  25  * @link
  26  */
  27
  28 class CI_Cache_memcached extends CI_Driver {
  29
  30         private $_memcached;    // Holds the memcached object
  31
  32         protected $_memcache_conf       = array(
  33                                         'default' => array(
  34                                                 'default_host'          => '127.0.0.1',
  35                                                 'default_port'          => 11211,
  36                                                 'default_weight'        => 1
  37                                         )
  38                                 );
  39
  40         // ------------------------------------------------------------------------
  41
  42         /**
  43          * Fetch from cache
  44          *
  45          * @param       mixed           unique key id
  46          * @return      mixed           data on success/false on failure
  47          */
  48         public function get($id)
  49         {
  50                 $data = $this->_memcached->get($id);
  51
  52                 return (is_array($data)) ? $data[0] : FALSE;
  53         }
  54
  55         // ------------------------------------------------------------------------
  56
  57         /**
  58          * Save
  59          *
  60          * @param       string          unique identifier
  61          * @param       mixed           data being cached
  62          * @param       int                     time to live
  63          * @return      boolean         true on success, false on failure
  64          */
  65         public function save($id, $data, $ttl = 60)
  66         {
  67                 return $this->_memcached->add($id, array($data, time(), $ttl), $ttl);
  68         }
  69
  70         // ------------------------------------------------------------------------
  71
  72         /**
  73          * Delete from Cache
  74          *
  75          * @param       mixed           key to be deleted.
  76          * @return      boolean         true on success, false on failure
  77          */
  78         public function delete($id)
  79         {
  80                 return $this->_memcached->delete($id);
  81         }
  82
  83         // ------------------------------------------------------------------------
  84
  85         /**
  86          * Clean the Cache
  87          *
  88          * @return      boolean         false on failure/true on success
  89          */
  90         public function clean()
  91         {
  92                 return $this->_memcached->flush();
  93         }
  94
  95         // ------------------------------------------------------------------------
  96
  97         /**
  98          * Cache Info
  99          *
 100          * @param       null            type not supported in memcached
 101          * @return      mixed           array on success, false on failure
 102          */
 103         public function cache_info($type = NULL)
 104         {
 105                 return $this->_memcached->getStats();
 106         }
 107
 108         // ------------------------------------------------------------------------
 109
 110         /**
 111          * Get Cache Metadata
 112          *
 113          * @param       mixed           key to get cache metadata on
 114          * @return      mixed           FALSE on failure, array on success.
 115          */
 116         public function get_metadata($id)
 117         {
 118                 $stored = $this->_memcached->get($id);
 119
 120                 if (count($stored) !== 3)
 121                 {
 122                         return FALSE;
 123                 }
 124
 125                 list($data, $time, $ttl) = $stored;
 126
 127                 return array(
 128                         'expire'        => $time + $ttl,
 129                         'mtime'         => $time,
 130                         'data'          => $data
 131                 );
 132         }
 133
 134         // ------------------------------------------------------------------------
 135
 136         /**
 137          * Setup memcached.
 138          */
 139         private function _setup_memcached()
 140         {
 141                 // Try to load memcached server info from the config file.
 142                 $CI =& get_instance();
 143                 if ($CI->config->load('memcached', TRUE, TRUE))
 144                 {
 145                         if (is_array($CI->config->config['memcached']))
 146                         {
 147                                 $this->_memcache_conf = NULL;
 148
 149                                 foreach ($CI->config->config['memcached'] as $name => $conf)
 150                                 {
 151                                         $this->_memcache_conf[$name] = $conf;
 152                                 }
 153                         }
 154                 }
 155
 156                 $this->_memcached = new Memcached();
 157
 158                 foreach ($this->_memcache_conf as $name => $cache_server)
 159                 {
 160                         if ( ! array_key_exists('hostname', $cache_server))
 161                         {
 162                                 $cache_server['hostname'] = $this->_default_options['default_host'];
 163                         }
 164
 165                         if ( ! array_key_exists('port', $cache_server))
 166                         {
 167                                 $cache_server['port'] = $this->_default_options['default_port'];
 168                         }
 169
 170                         if ( ! array_key_exists('weight', $cache_server))
 171                         {
 172                                 $cache_server['weight'] = $this->_default_options['default_weight'];
 173                         }
 174
 175                         $this->_memcached->addServer(
 176                                         $cache_server['hostname'], $cache_server['port'], $cache_server['weight']
 177                         );
 178                 }
 179         }
 180
 181         // ------------------------------------------------------------------------
 182
 183
 184         /**
 185          * Is supported
 186          *
 187          * Returns FALSE if memcached is not supported on the system.
 188          * If it is, we setup the memcached object & return TRUE
 189          */
 190         public function is_supported()
 191         {
 192                 if ( ! extension_loaded('memcached'))
 193                 {
 194                         log_message('error', 'The Memcached Extension must be loaded to use Memcached Cache.');
 195
 196                         return FALSE;
 197                 }
 198
 199                 $this->_setup_memcached();
 200                 return TRUE;
 201         }
 202
 203         // ------------------------------------------------------------------------
 204
 205 }
 206 // End Class
 207
 208 /* End of file Cache_memcached.php */
 209 /* Location: ./system/libraries/Cache/drivers/Cache_memcached.php */