1: <?php
  2: /**
  3:  * This file contains classes implementing security manager feature.
  4:  *
  5:  * @author Qiang Xue <qiang.xue@gmail.com>
  6:  * @link http://www.yiiframework.com/
  7:  * @copyright 2008-2013 Yii Software LLC
  8:  * @license http://www.yiiframework.com/license/
  9:  */
 10: 
 11: /**
 12:  * CStatePersister implements a file-based persistent data storage.
 13:  *
 14:  * It can be used to keep data available through multiple requests and sessions.
 15:  *
 16:  * By default, CStatePersister stores data in a file named 'state.bin' that is located
 17:  * under the application {@link CApplication::getRuntimePath runtime path}.
 18:  * You may change the location by setting the {@link stateFile} property.
 19:  *
 20:  * To retrieve the data from CStatePersister, call {@link load()}. To save the data,
 21:  * call {@link save()}.
 22:  *
 23:  * Comparison among state persister, session and cache is as follows:
 24:  * <ul>
 25:  * <li>session: data persisting within a single user session.</li>
 26:  * <li>state persister: data persisting through all requests/sessions (e.g. hit counter).</li>
 27:  * <li>cache: volatile and fast storage. It may be used as storage medium for session or state persister.</li>
 28:  * </ul>
 29:  *
 30:  * Since server resource is often limited, be cautious if you plan to use CStatePersister
 31:  * to store large amount of data. You should also consider using database-based persister
 32:  * to improve the throughput.
 33:  *
 34:  * CStatePersister is a core application component used to store global application state.
 35:  * It may be accessed via {@link CApplication::getStatePersister()}.
 36:  * page state persistent method based on cache.
 37:  *
 38:  * @author Qiang Xue <qiang.xue@gmail.com>
 39:  * @package system.base
 40:  * @since 1.0
 41:  */
 42: class CStatePersister extends CApplicationComponent implements IStatePersister
 43: {
 44:     /**
 45:      * @var string the file path storing the state data. Make sure the directory containing
 46:      * the file exists and is writable by the Web server process. If using relative path, also
 47:      * make sure the path is correct.
 48:      */
 49:     public $stateFile;
 50:     /**
 51:      * @var string the ID of the cache application component that is used to cache the state values.
 52:      * Defaults to 'cache' which refers to the primary cache application component.
 53:      * Set this property to false if you want to disable caching state values.
 54:      */
 55:     public $cacheID='cache';
 56: 
 57:     /**
 58:      * Initializes the component.
 59:      * This method overrides the parent implementation by making sure {@link stateFile}
 60:      * contains valid value.
 61:      */
 62:     public function init()
 63:     {
 64:         parent::init();
 65:         if($this->stateFile===null)
 66:             $this->stateFile=Yii::app()->getRuntimePath().DIRECTORY_SEPARATOR.'state.bin';
 67:         $dir=dirname($this->stateFile);
 68:         if(!is_dir($dir) || !is_writable($dir))
 69:             throw new CException(Yii::t('yii','Unable to create application state file "{file}". Make sure the directory containing the file exists and is writable by the Web server process.',
 70:                 array('{file}'=>$this->stateFile)));
 71:     }
 72: 
 73:     /**
 74:      * Loads state data from persistent storage.
 75:      * @return mixed state data. Null if no state data available.
 76:      */
 77:     public function load()
 78:     {
 79:         $stateFile=$this->stateFile;
 80:         if($this->cacheID!==false && ($cache=Yii::app()->getComponent($this->cacheID))!==null)
 81:         {
 82:             $cacheKey='Yii.CStatePersister.'.$stateFile;
 83:             if(($value=$cache->get($cacheKey))!==false)
 84:                 return unserialize($value);
 85:             elseif(($content=@file_get_contents($stateFile))!==false)
 86:             {
 87:                 $cache->set($cacheKey,$content,0,new CFileCacheDependency($stateFile));
 88:                 return unserialize($content);
 89:             }
 90:             else
 91:                 return null;
 92:         }
 93:         elseif(($content=@file_get_contents($stateFile))!==false)
 94:             return unserialize($content);
 95:         else
 96:             return null;
 97:     }
 98: 
 99:     /**
100:      * Saves application state in persistent storage.
101:      * @param mixed $state state data (must be serializable).
102:      */
103:     public function save($state)
104:     {
105:         file_put_contents($this->stateFile,serialize($state),LOCK_EX);
106:     }
107: }
108: