system/libraries/Cache/drivers/Cache_file.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_file extends CI_Driver {
  29
  30         protected $_cache_path;
  31
  32         /**
  33          * Constructor
  34          */
  35         public function __construct()
  36         {
  37                 $CI =& get_instance();
  38                 $CI->load->helper('file');
  39
  40                 $path = $CI->config->item('cache_path');
  41
  42                 $this->_cache_path = ($path == '') ? APPPATH.'cache/' : $path;
  43         }
  44
  45         // ------------------------------------------------------------------------
  46
  47         /**
  48          * Fetch from cache
  49          *
  50          * @param       mixed           unique key id
  51          * @return      mixed           data on success/false on failure
  52          */
  53         public function get($id)
  54         {
  55                 if ( ! file_exists($this->_cache_path.$id))
  56                 {
  57                         return FALSE;
  58                 }
  59
  60                 $data = read_file($this->_cache_path.$id);
  61                 $data = unserialize($data);
  62
  63                 if (time() >  $data['time'] + $data['ttl'])
  64                 {
  65                         unlink($this->_cache_path.$id);
  66                         return FALSE;
  67                 }
  68
  69                 return $data['data'];
  70         }
  71
  72         // ------------------------------------------------------------------------
  73
  74         /**
  75          * Save into cache
  76          *
  77          * @param       string          unique key
  78          * @param       mixed           data to store
  79          * @param       int                     length of time (in seconds) the cache is valid
  80          *                                              - Default is 60 seconds
  81          * @return      boolean         true on success/false on failure
  82          */
  83         public function save($id, $data, $ttl = 60)
  84         {
  85                 $contents = array(
  86                                 'time'          => time(),
  87                                 'ttl'           => $ttl,
  88                                 'data'          => $data
  89                         );
  90
  91                 if (write_file($this->_cache_path.$id, serialize($contents)))
  92                 {
  93                         @chmod($this->_cache_path.$id, 0777);
  94                         return TRUE;
  95                 }
  96
  97                 return FALSE;
  98         }
  99
 100         // ------------------------------------------------------------------------
 101
 102         /**
 103          * Delete from Cache
 104          *
 105          * @param       mixed           unique identifier of item in cache
 106          * @return      boolean         true on success/false on failure
 107          */
 108         public function delete($id)
 109         {
 110                 return unlink($this->_cache_path.$id);
 111         }
 112
 113         // ------------------------------------------------------------------------
 114
 115         /**
 116          * Clean the Cache
 117          *
 118          * @return      boolean         false on failure/true on success
 119          */
 120         public function clean()
 121         {
 122                 return delete_files($this->_cache_path);
 123         }
 124
 125         // ------------------------------------------------------------------------
 126
 127         /**
 128          * Cache Info
 129          *
 130          * Not supported by file-based caching
 131          *
 132          * @param       string  user/filehits
 133          * @return      mixed   FALSE
 134          */
 135         public function cache_info($type = NULL)
 136         {
 137                 return get_dir_file_info($this->_cache_path);
 138         }
 139
 140         // ------------------------------------------------------------------------
 141
 142         /**
 143          * Get Cache Metadata
 144          *
 145          * @param       mixed           key to get cache metadata on
 146          * @return      mixed           FALSE on failure, array on success.
 147          */
 148         public function get_metadata($id)
 149         {
 150                 if ( ! file_exists($this->_cache_path.$id))
 151                 {
 152                         return FALSE;
 153                 }
 154
 155                 $data = read_file($this->_cache_path.$id);
 156                 $data = unserialize($data);
 157
 158                 if (is_array($data))
 159                 {
 160                         $data = $data['data'];
 161                         $mtime = filemtime($this->_cache_path.$id);
 162
 163                         if ( ! isset($data['ttl']))
 164                         {
 165                                 return FALSE;
 166                         }
 167
 168                         return array(
 169                                 'expire'        => $mtime + $data['ttl'],
 170                                 'mtime'         => $mtime
 171                         );
 172                 }
 173
 174                 return FALSE;
 175         }
 176
 177         // ------------------------------------------------------------------------
 178
 179         /**
 180          * Is supported
 181          *
 182          * In the file driver, check to see that the cache directory is indeed writable
 183          *
 184          * @return boolean
 185          */
 186         public function is_supported()
 187         {
 188                 return is_really_writable($this->_cache_path);
 189         }
 190
 191         // ------------------------------------------------------------------------
 192 }
 193 // End Class
 194
 195 /* End of file Cache_file.php */
 196 /* Location: ./system/libraries/Cache/drivers/Cache_file.php */