system/libraries/Cache/Cache.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 Caching Class
  20  *
  21  * @package             CodeIgniter
  22  * @subpackage  Libraries
  23  * @category    Core
  24  * @author              ExpressionEngine Dev Team
  25  * @link
  26  */
  27 class CI_Cache extends CI_Driver_Library {
  28
  29         protected $valid_drivers        = array(
  30                 'cache_apc', 'cache_file', 'cache_memcached', 'cache_dummy'
  31         );
  32
  33         protected $_cache_path          = NULL;         // Path of cache files (if file-based cache)
  34         protected $_adapter                     = 'dummy';
  35         protected $_backup_driver;
  36
  37         // ------------------------------------------------------------------------
  38
  39         /**
  40          * Constructor
  41          *
  42          * @param array
  43          */
  44         public function __construct($config = array())
  45         {
  46                 if ( ! empty($config))
  47                 {
  48                         $this->_initialize($config);
  49                 }
  50         }
  51
  52         // ------------------------------------------------------------------------
  53
  54         /**
  55          * Get
  56          *
  57          * Look for a value in the cache.  If it exists, return the data
  58          * if not, return FALSE
  59          *
  60          * @param       string
  61          * @return      mixed           value that is stored/FALSE on failure
  62          */
  63         public function get($id)
  64         {
  65                 return $this->{$this->_adapter}->get($id);
  66         }
  67
  68         // ------------------------------------------------------------------------
  69
  70         /**
  71          * Cache Save
  72          *
  73          * @param       string          Unique Key
  74          * @param       mixed           Data to store
  75          * @param       int                     Length of time (in seconds) to cache the data
  76          *
  77          * @return      boolean         true on success/false on failure
  78          */
  79         public function save($id, $data, $ttl = 60)
  80         {
  81                 return $this->{$this->_adapter}->save($id, $data, $ttl);
  82         }
  83
  84         // ------------------------------------------------------------------------
  85
  86         /**
  87          * Delete from Cache
  88          *
  89          * @param       mixed           unique identifier of the item in the cache
  90          * @return      boolean         true on success/false on failure
  91          */
  92         public function delete($id)
  93         {
  94                 return $this->{$this->_adapter}->delete($id);
  95         }
  96
  97         // ------------------------------------------------------------------------
  98
  99         /**
 100          * Clean the cache
 101          *
 102          * @return      boolean         false on failure/true on success
 103          */
 104         public function clean()
 105         {
 106                 return $this->{$this->_adapter}->clean();
 107         }
 108
 109         // ------------------------------------------------------------------------
 110
 111         /**
 112          * Cache Info
 113          *
 114          * @param       string          user/filehits
 115          * @return      mixed           array on success, false on failure
 116          */
 117         public function cache_info($type = 'user')
 118         {
 119                 return $this->{$this->_adapter}->cache_info($type);
 120         }
 121
 122         // ------------------------------------------------------------------------
 123
 124         /**
 125          * Get Cache Metadata
 126          *
 127          * @param       mixed           key to get cache metadata on
 128          * @return      mixed           return value from child method
 129          */
 130         public function get_metadata($id)
 131         {
 132                 return $this->{$this->_adapter}->get_metadata($id);
 133         }
 134
 135         // ------------------------------------------------------------------------
 136
 137         /**
 138          * Initialize
 139          *
 140          * Initialize class properties based on the configuration array.
 141          *
 142          * @param       array
 143          * @return      void
 144          */
 145         private function _initialize($config)
 146         {
 147                 $default_config = array(
 148                                 'adapter',
 149                                 'memcached'
 150                         );
 151
 152                 foreach ($default_config as $key)
 153                 {
 154                         if (isset($config[$key]))
 155                         {
 156                                 $param = '_'.$key;
 157
 158                                 $this->{$param} = $config[$key];
 159                         }
 160                 }
 161
 162                 if (isset($config['backup']))
 163                 {
 164                         if (in_array('cache_'.$config['backup'], $this->valid_drivers))
 165                         {
 166                                 $this->_backup_driver = $config['backup'];
 167                         }
 168                 }
 169         }
 170
 171         // ------------------------------------------------------------------------
 172
 173         /**
 174          * Is the requested driver supported in this environment?
 175          *
 176          * @param       string  The driver to test.
 177          * @return      array
 178          */
 179         public function is_supported($driver)
 180         {
 181                 static $support = array();
 182
 183                 if ( ! isset($support[$driver]))
 184                 {
 185                         $support[$driver] = $this->{$driver}->is_supported();
 186                 }
 187
 188                 return $support[$driver];
 189         }
 190
 191         // ------------------------------------------------------------------------
 192
 193         /**
 194          * __get()
 195          *
 196          * @param       child
 197          * @return      object
 198          */
 199         public function __get($child)
 200         {
 201                 $obj = parent::__get($child);
 202
 203                 if ( ! $this->is_supported($child))
 204                 {
 205                         $this->_adapter = $this->_backup_driver;
 206                 }
 207
 208                 return $obj;
 209         }
 210
 211         // ------------------------------------------------------------------------
 212 }
 213 // End Class
 214
 215 /* End of file Cache.php */
 216 /* Location: ./system/libraries/Cache/Cache.php */