<?php
/* SVN FILE: $Id$ */
/**
 * Caching for Cake.
 *
 *
 * PHP versions 4 and 5
 *
 * CakePHP(tm) :  Rapid Development Framework <http://www.cakephp.org/>
 * Copyright 2005-2007, Cake Software Foundation, Inc.
 *								1785 E. Sahara Avenue, Suite 490-204
 *								Las Vegas, Nevada 89104
 *
 * Licensed under The MIT License
 * Redistributions of files must retain the above copyright notice.
 *
 * @filesource
 * @copyright		Copyright 2005-2007, Cake Software Foundation, Inc.
 * @link				http://www.cakefoundation.org/projects/info/cakephp CakePHP(tm) Project
 * @package			cake
 * @subpackage		cake.cake.libs
 * @since			CakePHP(tm) v 0.2.9
 * @version			$Revision$
 * @modifiedby		$LastChangedBy$
 * @lastmodified	$Date$
 * @license			http://www.opensource.org/licenses/mit-license.php The MIT License
 */
/**
 * Included libraries.
 *
 */
	if (!class_exists('Model')) {
		 uses('model' . DS . 'model');
	}
/**
 * Caching for Cake.
 *
 *
 * @package		cake
 * @subpackage	cake.cake.libs
 */
class Cache extends Model{
/**
 * Identifier. Either an MD5 string or NULL.
 *
 * @var string
 */
	var $id = null;
/**
 * Content container for cache data.
 *
 * @var unknown_type
 */
	var $data = null;
/**
 * Content to be cached.
 *
 * @var unknown_type
 */
	var $for_caching = null;
/**
 * Name of the database table used for caching.
 *
 * @var string
 */
	var $useTable = 'cache';
/**
 * Constructor. Generates an md5'ed id for internal use. Calls the constructor on Model as well.
 *
 * @param unknown_type $id
 */
	function __construct($id) {
		$this->id = (md5($id));
		parent::__construct($this->id);
	}
/**
 * Returns this object's id after setting it. If called without parameters the current object's id is returned.
 *
 * @param unknown_type $id
 * @return unknown
 */
	function id($id = null) {
		if (!$id) {
			return $this->id;
		}
		return ($this->id = $id);
	}
/**
 * Store given content in cache database.
 *
 * @param string $content Content to keep in cache.
 * @param int $keep_for Number of seconds to keep data in cache.
 * @return boolean				Success
 */
	function remember($content, $keep_for = CACHE_PAGES_FOR) {
		$data = addslashes($this->for_caching . $content);
		$expire = date("Y-m-d H:i:s", time() + ($keep_for > 0 ? $keep_for : 999999999));
		return $this->query("REPLACE {$this->useTable} (id,data,expire) VALUES ('{$this->id}', '{$data}', '{$expire}')");
	}
/**
 * Returns content from the Cache object itself, if the Cache object has a non-empty data property.
 * Else from the database cache.
 *
 * @return unknown
 */
	function restore() {
		if (empty($this->data['data'])) {
			return $this->find("id='{$this->id}' AND expire>NOW()");
		}
		return $this->data['data'];
	 }
/**
 * Returns true if the cache data property has current (non-stale) content for given id.
 *
 * @return boolean
 */
	function has() {
		return is_array($this->data = $this->find("id='{$this->id}' AND expire>NOW()"));
	}
/**
 * Appends $string to the for_caching property of the Cache object.
 *
 * @param string $string
 */
	function append($string) {
		$this->for_caching .= $string;
	}
/**
 * Clears the cache database table.
 *
 * @return unknown
 */
	function clear() {
		return $this->query("DELETE FROM {$this->useTable}");
	}
}
?>