<?php /** * TCachePageStatePersister class file * * @author Qiang Xue <qiang.xue@gmail.com> * @link http://www.pradosoft.com/ * @copyright Copyright © 2005-2008 PradoSoft * @license http://www.pradosoft.com/license/ * @version $Id$ * @package System.Web.UI */ /** * TCachePageStatePersister class * * TCachePageStatePersister implements a page state persistent method based on cache. * Page state are stored in cache (e.g. memcache, DB cache, etc.), and only a small token * is passed to the client side to identify the state. This greatly reduces the size of * the page state that needs to be transmitted between the server and the client. Of course, * this is at the cost of using server side resource. * * A cache module has to be loaded in order to use TCachePageStatePersister. * By default, TCachePageStatePersister will use the primary cache module. * A non-primary cache module can be used by setting {@link setCacheModuleID CacheModuleID}. * Any cache module, as long as it implements the interface {@link ICache}, may be used. * For example, one can use {@link TDbCache}, {@link TMemCache}, {@link TAPCCache}, etc. * * TCachePageStatePersister uses {@link setCacheTimeout CacheTimeout} to limit the data * that stores in cache. * * Since server resource is often limited, be cautious if you plan to use TCachePageStatePersister * for high-traffic Web pages. You may consider using a small {@link setCacheTimeout CacheTimeout}. * * There are a couple of ways to use TCachePageStatePersister. * One can override the page's {@link TPage::getStatePersister()} method and * create a TCachePageStatePersister instance there. * Or one can configure the pages to use TCachePageStatePersister in page configurations * as follows, * <code> * <pages StatePersisterClass="System.Web.UI.TCachePageStatePersister" * StatePersister.CacheModuleID="mycache" * StatePersister.CacheTimeout="3600" /> * </code> * Note in the above, we use StatePersister.CacheModuleID to configure the cache module ID * for the TCachePageStatePersister instance. * * The above configuration will affect the pages under the directory containing * this configuration and all its subdirectories. * To configure individual pages to use TCachePageStatePersister, use * <code> * <pages> * <page id="PageID" StatePersisterClass="System.Web.UI.TCachePageStatePersister" /> * </pages> * </code> * * @author Qiang Xue <qiang.xue@gmail.com> * @version $Id$ * @package System.Web.UI * @since 3.1.1 */ class TCachePageStatePersister extends TComponent implements IPageStatePersister { private $_prefix='statepersister'; private $_page; private $_cache=null; private $_cacheModuleID=''; private $_timeout=1800; /** * @param TPage the page that this persister works for */ public function getPage() { return $this->_page; } /** * @param TPage the page that this persister works for. */ public function setPage(TPage $page) { $this->_page=$page; } /** * @return string the ID of the cache module. */ public function getCacheModuleID() { return $this->_cacheModuleID; } /** * @param string the ID of the cache module. If not set, the primary cache module will be used. */ public function setCacheModuleID($value) { $this->_cacheModuleID=$value; } /** * @return ICache the cache module being used for data storage */ public function getCache() { if($this->_cache===null) { if($this->_cacheModuleID!=='') $cache=Prado::getApplication()->getModule($this->_cacheModuleID); else $cache=Prado::getApplication()->getCache(); if($cache===null || !($cache instanceof ICache)) { if($this->_cacheModuleID!=='') throw new TConfigurationException('cachepagestatepersister_cachemoduleid_invalid',$this->_cacheModuleID); else throw new TConfigurationException('cachepagestatepersister_cache_required'); } $this->_cache=$cache; } return $this->_cache; } /** * @return integer the number of seconds in which the cached state will expire. Defaults to 1800. */ public function getCacheTimeout() { return $this->_timeout; } /** * @param integer the number of seconds in which the cached state will expire. 0 means never expire. * @throws TInvalidDataValueException if the number is smaller than 0. */ public function setCacheTimeout($value) { if(($value=TPropertyValue::ensureInteger($value))>=0) $this->_timeout=$value; else throw new TInvalidDataValueException('cachepagestatepersister_timeout_invalid'); } /** * @return string prefix of cache variable name to avoid conflict with other cache data. Defaults to 'statepersister'. */ public function getKeyPrefix() { return $this->_prefix; } /** * @param string prefix of cache variable name to avoid conflict with other cache data */ public function setKeyPrefix($value) { $this->_prefix=$value; } /** * @param string micro timestamp when saving state occurs * @return string a key that is unique per user request */ protected function calculateKey($timestamp) { return $this->getKeyPrefix().':' . $this->_page->getRequest()->getUserHostAddress() . $this->_page->getPagePath() . $timestamp; } /** * Saves state in cache. * @param mixed state to be stored */ public function save($state) { $data=serialize($state); $timestamp=(string)microtime(true); $key=$this->calculateKey($timestamp); $this->getCache()->add($key,$data,$this->_timeout); $this->_page->setClientState(TPageStateFormatter::serialize($this->_page,$timestamp)); } /** * Loads page state from cache. * @return mixed the restored state * @throws THttpException if page state is corrupted */ public function load() { if(($timestamp=TPageStateFormatter::unserialize($this->_page,$this->_page->getRequestClientState()))!==null) { $key=$this->calculateKey($timestamp); if(($data=$this->getCache()->get($key))!==false) return unserialize($data); } throw new THttpException(400,'cachepagestatepersister_pagestate_corrupted'); } }