Subversion-Projekte lars-tiefland.cakephp

<?php

/* SVN FILE: $Id: file.php 7945 2008-12-19 02:16:01Z gwoo $ */

/**

 * File Storage engine for cache

 *

 *

 * PHP versions 4 and 5

 *

 * CakePHP(tm) :  Rapid Development Framework (http://www.cakephp.org)

 * Copyright 2005-2008, Cake Software Foundation, Inc. (http://www.cakefoundation.org)

 *

 * Licensed under The MIT License

 * Redistributions of files must retain the above copyright notice.

 *

 * @filesource

 * @copyright     Copyright 2005-2008, Cake Software Foundation, Inc. (http://www.cakefoundation.org)

 * @link          http://www.cakefoundation.org/projects/info/cakephp CakePHP(tm) Project

 * @package       cake

 * @subpackage    cake.cake.libs.cache

 * @since         CakePHP(tm) v 1.2.0.4933

 * @version       $Revision: 7945 $

 * @modifiedby    $LastChangedBy: gwoo $

 * @lastmodified  $Date: 2008-12-18 18:16:01 -0800 (Thu, 18 Dec 2008) $

 * @license       http://www.opensource.org/licenses/mit-license.php The MIT License

 */

/**

 * File Storage engine for cache

 *

 * @todo use the File and Folder classes (if it's not a too big performance hit)

 * @package       cake

 * @subpackage    cake.cake.libs.cache

 */

class FileEngine extends CacheEngine {

/**

 * Instance of File class

 *

 * @var object

 * @access private

 */

	var $__File = null;

/**

 * settings

 * 		path = absolute path to cache directory, default => CACHE

 * 		prefix = string prefix for filename, default => cake_

 * 		lock = enable file locking on write, default => false

 * 		serialize = serialize the data, default => true

 *

 * @var array

 * @see CacheEngine::__defaults

 * @access public

 */

	var $settings = array();

/**

 * Set to true if FileEngine::init(); and FileEngine::__active(); do not fail.

 *

 * @var boolean

 * @access private

 */

	var $__active = false;

/**

 * True unless FileEngine::__active(); fails

 *

 * @var boolean

 * @access private

 */

	var $__init = true;

/**

 * Initialize the Cache Engine

 *

 * Called automatically by the cache frontend

 * To reinitialize the settings call Cache::engine('EngineName', [optional] settings = array());

 *

 * @param array $setting array of setting for the engine

 * @return boolean True if the engine has been successfully initialized, false if not

 * @access public

 */

	function init($settings = array()) {

		parent::init(array_merge(

			array(

				'engine' => 'File', 'path' => CACHE, 'prefix'=> 'cake_', 'lock'=> false,

				'serialize'=> true, 'isWindows' => false

			),

			$settings

		));

		if (!isset($this->__File)) {

			if (!class_exists('File')) {

				require LIBS . 'file.php';

			}

			$this->__File =& new File($this->settings['path'] . DS . 'cake');

		}

		if (DIRECTORY_SEPARATOR === '\\') {

			$this->settings['isWindows'] = true;

		}

		$this->settings['path'] = $this->__File->Folder->cd($this->settings['path']);

		if (empty($this->settings['path'])) {

			return false;

		}

		return $this->__active();

	}

/**

 * Garbage collection. Permanently remove all expired and deleted data

 *

 * @return boolean True if garbage collection was succesful, false on failure

 * @access public

 */

	function gc() {

		return $this->clear(true);

	}

/**

 * Write data for key into cache

 *

 * @param string $key Identifier for the data

 * @param mixed $data Data to be cached

 * @param mixed $duration How long to cache the data, in seconds

 * @return boolean True if the data was succesfully cached, false on failure

 * @access public

 */

	function write($key, &$data, $duration) {

		if ($data === '' || !$this->__init) {

			return false;

		}

		if ($this->__setKey($key) === false) {

			return false;

		}

		$lineBreak = "\n";

		if ($this->settings['isWindows']) {

			$lineBreak = "\r\n";

		}

		if (!empty($this->settings['serialize'])) {

			if ($this->settings['isWindows']) {

				$data = str_replace('\\', '\\\\\\\\', serialize($data));

			} else {

				$data = serialize($data);

			}

		}

		if ($this->settings['lock']) {

			$this->__File->lock = true;

		}

		$expires = time() + $duration;

		$contents = $expires . $lineBreak . $data . $lineBreak;

		$success = $this->__File->write($contents);

		$this->__File->close();

		return $success;

	}

/**

 * Read a key from the cache

 *

 * @param string $key Identifier for the data

 * @return mixed The cached data, or false if the data doesn't exist, has expired, or if there was an error fetching it

 * @access public

 */

	function read($key) {

		if ($this->__setKey($key) === false || !$this->__init || !$this->__File->exists()) {

			return false;

		}

		if ($this->settings['lock']) {

			$this->__File->lock = true;

		}

		$time = time();

		$cachetime = intval($this->__File->read(11));

		if ($cachetime !== false && ($cachetime < $time || ($time + $this->settings['duration']) < $cachetime)) {

			$this->__File->close();

			$this->__File->delete();

			return false;

		}

		$data = $this->__File->read(true);

		if ($data !== '' && !empty($this->settings['serialize'])) {

			if ($this->settings['isWindows']) {

				$data = str_replace('\\\\\\\\', '\\', $data);

			}

			$data = unserialize((string)$data);

		}

		$this->__File->close();

		return $data;

	}

/**

 * Delete a key from the cache

 *

 * @param string $key Identifier for the data

 * @return boolean True if the value was successfully deleted, false if it didn't exist or couldn't be removed

 * @access public

 */

	function delete($key) {

		if ($this->__setKey($key) === false || !$this->__init) {

			return false;

		}

		return $this->__File->delete();

	}

/**

 * Delete all values from the cache

 *

 * @param boolean $check Optional - only delete expired cache items

 * @return boolean True if the cache was succesfully cleared, false otherwise

 * @access public

 */

	function clear($check) {

		if (!$this->__init) {

			return false;

		}

		$dir = dir($this->settings['path']);

		if ($check) {

			$now = time();

			$threshold = $now - $this->settings['duration'];

		}

		while (($entry = $dir->read()) !== false) {

			if ($this->__setKey($entry) === false) {

				continue;

			}

			if ($check) {

				$mtime = $this->__File->lastChange();

				if ($mtime === false || $mtime > $threshold) {

					continue;

				}

				$expires = $this->__File->read(11);

				$this->__File->close();

				if ($expires > $now) {

					continue;

				}

			}

			$this->__File->delete();

		}

		$dir->close();

		return true;

	}

/**

 * Get absolute file for a given key

 *

 * @param string $key The key

 * @return mixed Absolute cache file for the given key or false if erroneous

 * @access private

 */

	function __setKey($key) {

		$this->__File->Folder->cd($this->settings['path']);

		if ($key !== $this->__File->name) {

			$this->__File->name = $key;

			$this->__File->path = null;

		}

		if (!$this->__File->Folder->inPath($this->__File->pwd(), true)) {

			return false;

		}

	}

/**

 * Determine is cache directory is writable

 *

 * @return boolean

 * @access private

 */

	function __active() {

		if (!$this->__active && $this->__init && !is_writable($this->settings['path'])) {

			$this->__init = false;

			trigger_error(sprintf(__('%s is not writable', true), $this->settings['path']), E_USER_WARNING);

		} else {

			$this->__active = true;

		}

		return true;

	}

}

?>