Subversion-Projekte lars-tiefland.prado

<?php

/**

 * TSqlMapCacheModel, TSqlMapCacheTypes and TSqlMapCacheKey classes file.

 *

 * @author Wei Zhuo <weizhuo[at]gmail[dot]com>

 * @link http://www.pradosoft.com/

 * @copyright Copyright © 2005-2008 PradoSoft

 * @license http://www.pradosoft.com/license/

 * @version $Id: TSqlMapCacheModel.php 2541 2008-10-21 15:05:13Z qiang.xue $

 * @package System.Data.SqlMap.Configuration

 */

/**

 * TSqlMapCacheModel corresponds to the <cacheModel> sql mapping configuration tag.

 *

 * The results from a query Mapped Statement can be cached simply by specifying

 * the {@link CacheModel TSqlMapStatement::setCacheModel()} property in <statement> tag.

 * A cache model is a configured cache that is defined within the sql map

 * configuration file. Cache models are configured using the <cacheModel> element.

 *

 * The cache model uses a pluggable framework for supporting different types of

 * caches. The choice of cache is specified by the {@link Implementation setImplementation()}

 * property. The class name specified must be one of {@link TSqlMapCacheTypes}.

 *

 * The cache implementations, LRU and FIFO cache below do not persist across

 * requests. That is, once the request is complete, all cache data is lost.

 * These caches are useful queries that results in the same repeated data during

 * the current request.

 *

 * @author Wei Zhuo <weizho[at]gmail[dot]com>

 * @version $Id: TSqlMapCacheModel.php 2541 2008-10-21 15:05:13Z qiang.xue $

 * @package System.Data.SqlMap.Configuration

 * @since 3.1

 */

class TSqlMapCacheModel extends TComponent

{

	private $_cache;

	private $_hits = 0;

	private $_requests = 0;

	private $_id;

	private $_implementation='basic';

	private $_properties = array();

	/**

	 * @return string unique cache model identifier.

	 */

	public function getID()

	{

		return $this->_id;

	}

	/**

	 * @param string unique cache model identifier.

	 */

	public function setID($value)

	{

		$this->_id = $value;

	}

	/**

	 * @return string cache implements of TSqlMapCacheTypes, either 'Basic', 'LRU' or 'FIFO'.

	 */

	public function getImplementation()

	{

		return $this->_implementation;

	}

	/**

	 * @param string cache implements of TSqlMapCacheTypes, either 'Basic', 'LRU' or 'FIFO'.

	 */

	public function setImplementation($value)

	{

		$this->_implementation = TPropertyValue::ensureEnum($value,'TSqlMapCacheTypes');

	}

	/**

	 * Initialize the cache implementation, sets the actual cache contain if supplied.

	 * @param ISqLMapCache cache implementation instance.

	 */

	public function initialize($cache=null)

	{

		if(is_null($cache))

			$this->_cache= Prado::createComponent($this->getImplementationClass());

		else

			$this->_cache=$cache;

	}

	/**

	 * @return string cache implementation class name.

	 */

	public function getImplementationClass()

	{

		switch(TPropertyValue::ensureEnum($this->_implementation,'TSqlMapCacheTypes'))

		{

			case TSqlMapCacheTypes::FIFO: return 'TSqlMapFifoCache';

			case TSqlMapCacheTypes::LRU : return 'TSqlMapLruCache';

			case TSqlMapCacheTypes::Basic : return 'TSqlMapApplicationCache';

		}

	}

	/**

	 * Register a mapped statement that will trigger a cache flush.

	 * @param TMappedStatement mapped statement that may flush the cache.

	 */

	public function registerTriggerStatement($mappedStatement)

	{

		$mappedStatement->attachEventHandler('OnExecuteQuery',array($this, 'flush'));

	}

	/**

	 * Clears the cache.

	 */

	public function flush()

	{

		$this->_cache->flush();

	}

	/**

	 * @param TSqlMapCacheKey|string cache key

	 * @return mixed cached value.

	 */

	public function get($key)

	{

		if($key instanceof TSqlMapCacheKey)

			$key = $key->getHash();

		//if flush ?

		$value = $this->_cache->get($key);

		$this->_requests++;

		if(!is_null($value))

			$this->_hits++;

		return $value;

	}

	/**

	 * @param TSqlMapCacheKey|string cache key

	 * @param mixed value to be cached.

	 */

	public function set($key, $value)

	{

		if($key instanceof TSqlMapCacheKey)

			$key = $key->getHash();

		if(!is_null($value))

			$this->_cache->set($key, $value);

	}

	/**

	 * @return float cache hit ratio.

	 */

	public function getHitRatio()

	{

		if($this->_requests != 0)

			return $this->_hits / $this->_requests;

		else

			return 0;

	}

}

/**

 * TSqlMapCacheTypes enumerable class.

 *

 * Implemented cache are 'Basic', 'FIFO' and 'LRU'.

 *

 * @author Wei Zhuo <weizho[at]gmail[dot]com>

 * @version $Id: TSqlMapCacheModel.php 2541 2008-10-21 15:05:13Z qiang.xue $

 * @package System.Data.SqlMap.Configuration

 * @since 3.1

 */

class TSqlMapCacheTypes extends TEnumerable

{

	const Basic='Basic';

	const FIFO='FIFO';

	const LRU='LRU';

}

/**

 * TSqlMapCacheKey class.

 *

 * Provides a hash of the object to be cached.

 *

 * @author Wei Zhuo <weizho[at]gmail[dot]com>

 * @version $Id: TSqlMapCacheModel.php 2541 2008-10-21 15:05:13Z qiang.xue $

 * @package System.Data.SqlMap.Configuration

 * @since 3.1

 */

class TSqlMapCacheKey

{

	private $_key;

	/**

	 * @param mixed object to be cached.

	 */

	public function __construct($object)

	{

		$this->_key = $this->generateKey(serialize($object));

	}

	/**

	 * @param string serialized object

	 * @return string crc32 hash of the serialized object.

	 */

	protected function generateKey($string)

	{

		return sprintf('%x',crc32($string));

	}

	/**

	 * @return string object hash.

	 */

	public function getHash()

	{

		return $this->_key;

	}

}