www.gusucode.com > FavShop网店系统源码程序 > FavShop网店系统 1.0/upload/cake/libs/cache.php
<?php
/* SVN FILE: $Id: cache.php 6311 2008-01-02 06:33:52Z phpnut $ */
/**
* Caching for CakePHP.
*
*
* PHP versions 4 and 5
*
* CakePHP(tm) : Rapid Development Framework <http://www.cakephp.org/>
* Copyright 2005-2008, 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 2005-2008, 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 1.2.0.4933
* @version $Revision: 6311 $
* @modifiedby $LastChangedBy: phpnut $
* @lastmodified $Date: 2008-01-02 00:33:52 -0600 (Wed, 02 Jan 2008) $
* @license http://www.opensource.org/licenses/mit-license.php The MIT License
*/
/**
* Included libraries.
*/
if (!class_exists('object')) {
uses('object');
}
/**
* Caching for CakePHP.
*
* @package cake
* @subpackage cake.cake.libs
*/
class Cache extends Object {
/**
* Cache engine to use
*
* @var object
* @access protected
*/
var $_Engine = null;
/**
* Cache configuration stack
*
* @var array
* @access private
*/
var $__config = array();
/**
* Holds name of the current configuration being used
*
* @var array
* @access private
*/
var $__name = null;
/**
* Returns a singleton instance
*
* @return object
* @access public
*/
function &getInstance() {
static $instance = array();
if (!isset($instance[0]) || !$instance[0]) {
$instance[0] =& new Cache();
}
return $instance[0];
}
/**
* Tries to find and include a file for a cache engine and returns object instance
*
* @param $name Name of the engine (without 'Engine')
* @return mixed $engine object or null
* @access private
*/
function __loadEngine($name) {
if (!class_exists($name . 'Engine')) {
$fileName = LIBS . DS . 'cache' . DS . strtolower($name) . '.php';
if (!require($fileName)) {
return false;
}
}
return true;
}
/**
* Set the cache configuration to use
*
* @see app/config/core.php for configuration settings
* @param string $name Name of the configuration
* @param array $settings Optional associative array of settings passed to the engine
* @return array(engine, settings) on success, false on failure
* @access public
*/
function config($name = 'default', $settings = array()) {
$_this =& Cache::getInstance();
if (is_array($name)) {
extract($name);
}
if (isset($_this->__config[$name])) {
$settings = array_merge($_this->__config[$name], $settings);
} elseif (!empty($settings)) {
$_this->__config[$name] = $settings;
} elseif ($_this->__name !== null && isset($_this->__config[$_this->__name])) {
$name = $_this->__name;
$settings = $_this->__config[$_this->__name];
} else {
$name = 'default';
if(!empty($_this->__config['default'])) {
$settings = $_this->__config['default'];
} else {
$settings = array('engine'=>'File');
}
}
$engine = 'File';
if (!empty($settings['engine'])) {
$engine = $settings['engine'];
}
if ($name !== $_this->__name) {
if ($_this->engine($engine, $settings) === false) {
return false;
}
$_this->__name = $name;
$_this->__config[$name] = $_this->settings($engine);
}
$settings = $_this->__config[$name];
return compact('engine', 'settings');
}
/**
* Set the cache engine to use or modify settings for one instance
*
* @param string $name Name of the engine (without 'Engine')
* @param array $settings Optional associative array of settings passed to the engine
* @return boolean True on success, false on failure
* @access public
*/
function engine($name = 'File', $settings = array()) {
if (!$name || Configure::read('Cache.disable')) {
return false;
}
$cacheClass = $name . 'Engine';
$_this =& Cache::getInstance();
if (!isset($_this->_Engine[$name])) {
if ($_this->__loadEngine($name) === false) {
return false;
}
$_this->_Engine[$name] =& new $cacheClass();
}
if ($_this->_Engine[$name]->init($settings)) {
if (time() % $_this->_Engine[$name]->settings['probability'] == 0) {
$_this->_Engine[$name]->gc();
}
return true;
}
$_this->_Engine[$name] = null;
return false;
}
/**
* Garbage collection
*
* Permanently remove all expired and deleted data
*
* @access public
*/
function gc() {
$_this =& Cache::getInstance();
$config = $_this->config();
extract($config);
$_this->_Engine[$engine]->gc();
}
/**
* Write data for key into cache
*
* @param string $key Identifier for the data
* @param mixed $value Data to be cached - anything except a resource
* @param mixed $duration Optional - string configuration name OR how long to cache the data, either in seconds or a
* string that can be parsed by the strtotime() function OR array('config' => 'default', 'duration' => '3600')
* @return boolean True if the data was successfully cached, false on failure
* @access public
*/
function write($key, $value, $duration = null) {
$_this =& Cache::getInstance();
$config = null;
if (is_array($duration)) {
extract($duration);
} elseif (isset($_this->__config[$duration])) {
$config = $duration;
$duration = null;
}
$config = $_this->config($config);
if (!is_array($config)) {
return null;
}
extract($config);
if (!$_this->isInitialized($engine)) {
return false;
}
if (!$key = $_this->__key($key)) {
return false;
}
if (is_resource($value)) {
return false;
}
if (!$duration) {
$duration = $settings['duration'];
}
$duration = ife(is_numeric($duration), intval($duration), strtotime($duration) - time());
if ($duration < 1) {
return false;
}
$success = $_this->_Engine[$engine]->write($key, $value, $duration);
$_this->_Engine[$engine]->init($settings);
return $success;
}
/**
* Read a key from the cache
*
* @param string $key Identifier for the data
* @param string $config name of the configuration to use
* @return mixed The cached data, or false if the data doesn't exist, has expired, or if there was an error fetching it
* @access public
*/
function read($key, $config = null) {
$_this =& Cache::getInstance();
$config = $_this->config($config);
if (!is_array($config)) {
return null;
}
extract($config);
if (!$_this->isInitialized($engine)) {
return false;
}
if (!$key = $_this->__key($key)) {
return false;
}
$success = $_this->_Engine[$engine]->read($key);
$_this->_Engine[$engine]->init($settings);
return $success;
}
/**
* Delete a key from the cache
*
* @param string $key Identifier for the data
* @param string $config name of the configuration to use
* @return boolean True if the value was succesfully deleted, false if it didn't exist or couldn't be removed
* @access public
*/
function delete($key, $config = null) {
$_this =& Cache::getInstance();
$config = $_this->config($config);
extract($config);
if (!$_this->isInitialized($engine)) {
return false;
}
if (!$key = $_this->__key($key)) {
return false;
}
$success = $_this->_Engine[$engine]->delete($key);
$_this->_Engine[$engine]->init($settings);
return $success;
}
/**
* Delete all keys from the cache
*
* @param boolean $check if true will check expiration, otherwise delete all
* @param string $config name of the configuration to use
* @return boolean True if the cache was succesfully cleared, false otherwise
* @access public
*/
function clear($check = false, $config = null) {
$_this =& Cache::getInstance();
$config = $_this->config($config);
extract($config);
if (!$_this->isInitialized($engine)) {
return false;
}
$success = $_this->_Engine[$engine]->clear($check);
$_this->_Engine[$engine]->init($settings);
return $success;
}
/**
* Check if Cache has initialized a working storage engine
*
* @param string $engine Name of the engine
* @param string $config Name of the configuration setting
* @return bool
* @access public
*/
function isInitialized($engine = null) {
if (Configure::read('Cache.disable')) {
return false;
}
$_this =& Cache::getInstance();
if (!$engine && isset($_this->__config[$_this->__name]['engine'])) {
$engine = $_this->__config[$_this->__name]['engine'];
}
return isset($_this->_Engine[$engine]);
}
/**
* Return the settings for current cache engine
*
* @param string $engine Name of the engine
* @return array list of settings for this engine
* @access public
*/
function settings($engine = null) {
$_this =& Cache::getInstance();
if (!$engine && isset($_this->__config[$_this->__name]['engine'])) {
$engine = $_this->__config[$_this->__name]['engine'];
}
if (isset($_this->_Engine[$engine]) && !is_null($_this->_Engine[$engine])) {
return $_this->_Engine[$engine]->settings();
}
return array();
}
/**
* generates a safe key
*
* @param string $key the key passed over
* @return mixed string $key or false
* @access private
*/
function __key($key) {
if (empty($key)) {
return false;
}
$key = str_replace(array(DS, '/', '.'), '_', strval($key));
return $key;
}
}
/**
* Storage engine for CakePHP caching
*
* @package cake
* @subpackage cake.cake.libs
*/
class CacheEngine extends Object {
/**
* settings of current engine instance
*
* @var int
* @access public
*/
var $settings;
/**
* Iitialize the cache engine
*
* Called automatically by the cache frontend
*
* @param array $params Associative array of parameters for the engine
* @return boolean True if the engine has been succesfully initialized, false if not
* @access public
*/
function init($settings = array()) {
$this->settings = array_merge(array('duration'=> 3600, 'probability'=> 100), $settings);
return true;
}
/**
* Garbage collection
*
* Permanently remove all expired and deleted data
*
* @access public
*/
function gc() {
}
/**
* Write value for a key into cache
*
* @param string $key Identifier for the data
* @param mixed $value 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, &$value, $duration) {
trigger_error(sprintf(__('Method write() not implemented in %s', true), get_class($this)), E_USER_ERROR);
}
/**
* 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) {
trigger_error(sprintf(__('Method read() not implemented in %s', true), get_class($this)), E_USER_ERROR);
}
/**
* Delete a key from the cache
*
* @param string $key Identifier for the data
* @return boolean True if the value was succesfully deleted, false if it didn't exist or couldn't be removed
* @access public
*/
function delete($key) {
}
/**
* Delete all keys from the cache
*
* @param boolean $check if true will check expiration, otherwise delete all
* @return boolean True if the cache was succesfully cleared, false otherwise
* @access public
*/
function clear($check) {
}
/**
* Cache Engine settings
*
* @return array settings
* @access public
*/
function settings() {
return $this->settings;
}
}
?>