khanat-code-old/code/web/public_php/webtt/cake/libs/cache.php
2014-09-05 18:46:13 -07:00

702 lines
18 KiB
PHP

<?php
/**
* Caching for CakePHP.
*
*
* PHP versions 4 and 5
*
* CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
* Copyright 2005-2010, Cake Software Foundation, Inc. (http://cakefoundation.org)
*
* Licensed under The MIT License
* Redistributions of files must retain the above copyright notice.
*
* @copyright Copyright 2005-2010, Cake Software Foundation, Inc. (http://cakefoundation.org)
* @link http://cakephp.org CakePHP(tm) Project
* @package cake
* @subpackage cake.cake.libs
* @since CakePHP(tm) v 1.2.0.4933
* @license MIT License (http://www.opensource.org/licenses/mit-license.php)
*/
/**
* Caching for CakePHP.
*
* @package cake
* @subpackage cake.cake.libs
*/
class Cache {
/**
* Cache configuration stack
* Keeps the permanent/default settings for each cache engine.
* These settings are used to reset the engines after temporary modification.
*
* @var array
* @access private
*/
var $__config = array();
/**
* Holds name of the current configuration name being used.
*
* @var array
* @access private
*/
var $__name = 'default';
/**
* Whether to reset the settings with the next call to Cache::set();
*
* @var array
* @access private
*/
var $__reset = false;
/**
* Engine instances keyed by configuration name.
*
* @var array
*/
var $_engines = array();
/**
* Returns a singleton instance
*
* @return object
* @access public
* @static
*/
function &getInstance() {
static $instance = array();
if (!$instance) {
$instance[0] =& new Cache();
}
return $instance[0];
}
/**
* Set the cache configuration to use. config() can
* both create new configurations, return the settings for already configured
* configurations. It also sets the 'default' configuration to use for subsequent
* operations.
*
* To create a new configuration:
*
* `Cache::config('my_config', array('engine' => 'File', 'path' => TMP));`
*
* To get the settings for a configuration, and set it as the currently selected configuration
*
* `Cache::config('default');`
*
* The following keys are used in core cache engines:
*
* - `duration` Specify how long items in this cache configuration last.
* - `prefix` Prefix appended to all entries. Good for when you need to share a keyspace
* with either another cache config or annother application.
* - `probability` Probability of hitting a cache gc cleanup. Setting to 0 will disable
* cache::gc from ever being called automatically.
* - `servers' Used by memcache. Give the address of the memcached servers to use.
* - `compress` Used by memcache. Enables memcache's compressed format.
* - `serialize` Used by FileCache. Should cache objects be serialized first.
* - `path` Used by FileCache. Path to where cachefiles should be saved.
* - `lock` Used by FileCache. Should files be locked before writing to them?
* - `user` Used by Xcache. Username for XCache
* - `password` Used by Xcache. Password for XCache
*
* @see app/config/core.php for configuration settings
* @param string $name Name of the configuration
* @param array $settings Optional associative array of settings passed to the engine
* @return array(engine, settings) on success, false on failure
* @access public
* @static
*/
function config($name = null, $settings = array()) {
$self =& Cache::getInstance();
if (is_array($name)) {
$settings = $name;
}
if ($name === null || !is_string($name)) {
$name = $self->__name;
}
$current = array();
if (isset($self->__config[$name])) {
$current = $self->__config[$name];
}
if (!empty($settings)) {
$self->__config[$name] = array_merge($current, $settings);
}
if (empty($self->__config[$name]['engine'])) {
return false;
}
$engine = $self->__config[$name]['engine'];
$self->__name = $name;
if (!isset($self->_engines[$name])) {
$self->_buildEngine($name);
$settings = $self->__config[$name] = $self->settings($name);
} elseif ($settings = $self->set($self->__config[$name])) {
$self->__config[$name] = $settings;
}
return compact('engine', 'settings');
}
/**
* Finds and builds the instance of the required engine class.
*
* @param string $name Name of the config array that needs an engine instance built
* @return void
* @access protected
*/
function _buildEngine($name) {
$config = $this->__config[$name];
list($plugin, $class) = pluginSplit($config['engine']);
$cacheClass = $class . 'Engine';
if (!class_exists($cacheClass) && $this->__loadEngine($class, $plugin) === false) {
return false;
}
$cacheClass = $class . 'Engine';
$this->_engines[$name] =& new $cacheClass();
if ($this->_engines[$name]->init($config)) {
if ($this->_engines[$name]->settings['probability'] && time() % $this->_engines[$name]->settings['probability'] === 0) {
$this->_engines[$name]->gc();
}
return true;
}
return false;
}
/**
* Returns an array containing the currently configured Cache settings.
*
* @return array Array of configured Cache config names.
*/
function configured() {
$self =& Cache::getInstance();
return array_keys($self->__config);
}
/**
* Drops a cache engine. Deletes the cache configuration information
* If the deleted configuration is the last configuration using an certain engine,
* the Engine instance is also unset.
*
* @param string $name A currently configured cache config you wish to remove.
* @return boolen success of the removal, returns false when the config does not exist.
*/
function drop($name) {
$self =& Cache::getInstance();
if (!isset($self->__config[$name])) {
return false;
}
unset($self->__config[$name]);
unset($self->_engines[$name]);
return true;
}
/**
* 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, $plugin = null) {
if ($plugin) {
return App::import('Lib', $plugin . '.cache' . DS . $name, false);
} else {
$core = App::core();
$path = $core['libs'][0] . 'cache' . DS . strtolower($name) . '.php';
if (file_exists($path)) {
require $path;
return true;
}
return App::import('Lib', 'cache' . DS . $name, false);
}
}
/**
* Temporarily change settings to current config options. if no params are passed, resets settings if needed
* Cache::write() will reset the configuration changes made
*
* @param mixed $settings Optional string for simple name-value pair or array
* @param string $value Optional for a simple name-value pair
* @return array Array of settings.
* @access public
* @static
*/
function set($settings = array(), $value = null) {
$self =& Cache::getInstance();
if (!isset($self->__config[$self->__name]) || !isset($self->_engines[$self->__name])) {
return false;
}
$name = $self->__name;
if (!empty($settings)) {
$self->__reset = true;
}
if ($self->__reset === true) {
if (empty($settings)) {
$self->__reset = false;
$settings = $self->__config[$name];
} else {
if (is_string($settings) && $value !== null) {
$settings = array($settings => $value);
}
$settings = array_merge($self->__config[$name], $settings);
if (isset($settings['duration']) && !is_numeric($settings['duration'])) {
$settings['duration'] = strtotime($settings['duration']) - time();
}
}
$self->_engines[$name]->settings = $settings;
}
return $self->settings($name);
}
/**
* Garbage collection
*
* Permanently remove all expired and deleted data
*
* @return void
* @access public
* @static
*/
function gc() {
$self =& Cache::getInstance();
$self->_engines[$self->__name]->gc();
}
/**
* Write data for key into cache. Will automatically use the currently
* active cache configuration. To set the currently active configuration use
* Cache::config()
*
* ### Usage:
*
* Writing to the active cache config:
*
* `Cache::write('cached_data', $data);`
*
* Writing to a specific cache config:
*
* `Cache::write('cached_data', $data, 'long_term');`
*
* @param string $key Identifier for the data
* @param mixed $value Data to be cached - anything except a resource
* @param string $config Optional string configuration name to write to.
* @return boolean True if the data was successfully cached, false on failure
* @access public
* @static
*/
function write($key, $value, $config = null) {
$self =& Cache::getInstance();
if (!$config) {
$config = $self->__name;
}
$settings = $self->settings($config);
if (empty($settings)) {
return null;
}
if (!$self->isInitialized($config)) {
return false;
}
$key = $self->_engines[$config]->key($key);
if (!$key || is_resource($value)) {
return false;
}
$success = $self->_engines[$config]->write($settings['prefix'] . $key, $value, $settings['duration']);
$self->set();
return $success;
}
/**
* Read a key from the cache. Will automatically use the currently
* active cache configuration. To set the currently active configuration use
* Cache::config()
*
* ### Usage:
*
* Reading from the active cache configuration.
*
* `Cache::read('my_data');`
*
* Reading from a specific cache configuration.
*
* `Cache::read('my_data', 'long_term');`
*
* @param string $key Identifier for the data
* @param string $config optional name of the configuration to use.
* @return mixed The cached data, or false if the data doesn't exist, has expired, or if there was an error fetching it
* @access public
* @static
*/
function read($key, $config = null) {
$self =& Cache::getInstance();
if (!$config) {
$config = $self->__name;
}
$settings = $self->settings($config);
if (empty($settings)) {
return null;
}
if (!$self->isInitialized($config)) {
return false;
}
$key = $self->_engines[$config]->key($key);
if (!$key) {
return false;
}
$success = $self->_engines[$config]->read($settings['prefix'] . $key);
if ($config !== null && $config !== $self->__name) {
$self->set();
}
return $success;
}
/**
* Increment a number under the key and return incremented value.
*
* @param string $key Identifier for the data
* @param integer $offset How much to add
* @param string $config Optional string configuration name. If not specified the current
* default config will be used.
* @return mixed new value, or false if the data doesn't exist, is not integer,
* or if there was an error fetching it.
* @access public
*/
function increment($key, $offset = 1, $config = null) {
$self =& Cache::getInstance();
if (!$config) {
$config = $self->__name;
}
$settings = $self->settings($config);
if (empty($settings)) {
return null;
}
if (!$self->isInitialized($config)) {
return false;
}
$key = $self->_engines[$config]->key($key);
if (!$key || !is_integer($offset) || $offset < 0) {
return false;
}
$success = $self->_engines[$config]->increment($settings['prefix'] . $key, $offset);
$self->set();
return $success;
}
/**
* Decrement a number under the key and return decremented value.
*
* @param string $key Identifier for the data
* @param integer $offset How much to substract
* @param string $config Optional string configuration name, if not specified the current
* default config will be used.
* @return mixed new value, or false if the data doesn't exist, is not integer,
* or if there was an error fetching it
* @access public
*/
function decrement($key, $offset = 1, $config = null) {
$self =& Cache::getInstance();
if (!$config) {
$config = $self->__name;
}
$settings = $self->settings($config);
if (empty($settings)) {
return null;
}
if (!$self->isInitialized($config)) {
return false;
}
$key = $self->_engines[$config]->key($key);
if (!$key || !is_integer($offset) || $offset < 0) {
return false;
}
$success = $self->_engines[$config]->decrement($settings['prefix'] . $key, $offset);
$self->set();
return $success;
}
/**
* Delete a key from the cache. Will automatically use the currently
* active cache configuration. To set the currently active configuration use
* Cache::config()
*
* ### Usage:
*
* Deleting from the active cache configuration.
*
* `Cache::delete('my_data');`
*
* Deleting from a specific cache configuration.
*
* `Cache::delete('my_data', 'long_term');`
*
* @param string $key Identifier for the data
* @param string $config name of the configuration to use
* @return boolean True if the value was succesfully deleted, false if it didn't exist or couldn't be removed
* @access public
* @static
*/
function delete($key, $config = null) {
$self =& Cache::getInstance();
if (!$config) {
$config = $self->__name;
}
$settings = $self->settings($config);
if (empty($settings)) {
return null;
}
if (!$self->isInitialized($config)) {
return false;
}
$key = $self->_engines[$config]->key($key);
if (!$key) {
return false;
}
$success = $self->_engines[$config]->delete($settings['prefix'] . $key);
$self->set();
return $success;
}
/**
* Delete all keys from the cache.
*
* @param boolean $check if true will check expiration, otherwise delete all
* @param string $config name of the configuration to use
* @return boolean True if the cache was succesfully cleared, false otherwise
* @access public
* @static
*/
function clear($check = false, $config = null) {
$self =& Cache::getInstance();
if (!$config) {
$config = $self->__name;
}
$settings = $self->settings($config);
if (empty($settings)) {
return null;
}
if (!$self->isInitialized($config)) {
return false;
}
$success = $self->_engines[$config]->clear($check);
$self->set();
return $success;
}
/**
* Check if Cache has initialized a working config for the given name.
*
* @param string $engine Name of the engine
* @param string $config Name of the configuration setting
* @return bool Whether or not the config name has been initialized.
* @access public
* @static
*/
function isInitialized($name = null) {
if (Configure::read('Cache.disable')) {
return false;
}
$self =& Cache::getInstance();
if (!$name && isset($self->__config[$self->__name])) {
$name = $self->__name;
}
return isset($self->_engines[$name]);
}
/**
* Return the settings for current cache engine. If no name is supplied the settings
* for the 'active default' configuration will be returned. To set the 'active default'
* configuration use `Cache::config()`
*
* @param string $engine Name of the configuration to get settings for.
* @return array list of settings for this engine
* @see Cache::config()
* @access public
* @static
*/
function settings($name = null) {
$self =& Cache::getInstance();
if (!$name && isset($self->__config[$self->__name])) {
$name = $self->__name;
}
if (!empty($self->_engines[$name])) {
return $self->_engines[$name]->settings();
}
return array();
}
/**
* Write the session when session data is persisted with cache.
*
* @return void
* @access public
*/
function __destruct() {
if (Configure::read('Session.save') == 'cache' && function_exists('session_write_close')) {
session_write_close();
}
}
}
/**
* Storage engine for CakePHP caching
*
* @package cake
* @subpackage cake.cake.libs
*/
class CacheEngine {
/**
* Settings of current engine instance
*
* @var int
* @access public
*/
var $settings = array();
/**
* Initialize 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('prefix' => 'cake_', 'duration'=> 3600, 'probability'=> 100),
$this->settings,
$settings
);
if (!is_numeric($this->settings['duration'])) {
$this->settings['duration'] = strtotime($this->settings['duration']) - time();
}
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);
}
/**
* Increment a number under the key and return incremented value
*
* @param string $key Identifier for the data
* @param integer $offset How much to add
* @return New incremented value, false otherwise
* @access public
*/
function increment($key, $offset = 1) {
trigger_error(sprintf(__('Method increment() not implemented in %s', true), get_class($this)), E_USER_ERROR);
}
/**
* Decrement a number under the key and return decremented value
*
* @param string $key Identifier for the data
* @param integer $value How much to substract
* @return New incremented value, false otherwise
* @access public
*/
function decrement($key, $offset = 1) {
trigger_error(sprintf(__('Method decrement() not implemented in %s', true), get_class($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;
}
/**
* Generates a safe key for use with cache engine storage engines.
*
* @param string $key the key passed over
* @return mixed string $key or false
* @access public
*/
function key($key) {
if (empty($key)) {
return false;
}
$key = Inflector::underscore(str_replace(array(DS, '/', '.'), '_', strval($key)));
return $key;
}
}