/lib/Cake/Cache/Cache.php
PHP | 602 lines | 231 code | 48 blank | 323 comment | 50 complexity | a822d0a4c58ddced710c6c5bf72678c4 MD5 | raw file
- <?php
- /**
- * Caching for CakePHP.
- *
- *
- * PHP 5
- *
- * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
- * Copyright 2005-2011, Cake Software Foundation, Inc. (http://cakefoundation.org)
- *
- * Licensed under The MIT License
- * Redistributions of files must retain the above copyright notice.
- *
- * @copyright Copyright 2005-2011, Cake Software Foundation, Inc. (http://cakefoundation.org)
- * @link http://cakephp.org CakePHP(tm) Project
- * @package Cake.Cache
- * @since CakePHP(tm) v 1.2.0.4933
- * @license MIT License (http://www.opensource.org/licenses/mit-license.php)
- */
- App::uses('Inflector', 'Utility');
- /**
- * Cache provides a consistent interface to Caching in your application. It allows you
- * to use several different Cache engines, without coupling your application to a specific
- * implementation. It also allows you to change out cache storage or configuration without effecting
- * the rest of your application.
- *
- * You can configure Cache engines in your application's `bootstrap.php` file. A sample configuration would
- * be
- *
- * {{{
- * Cache::config('shared', array(
- * 'engine' => 'Apc',
- * 'prefix' => 'my_app_'
- * ));
- * }}}
- *
- * This would configure an APC cache engine to the 'shared' alias. You could then read and write
- * to that cache alias by using it for the `$config` parameter in the various Cache methods. In
- * general all Cache operations are supported by all cache engines. However, Cache::increment() and
- * Cache::decrement() are not supported by File caching.
- *
- * @package Cake.Cache
- */
- 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
- */
- protected static $_config = array();
- /**
- * Whether to reset the settings with the next call to Cache::set();
- *
- * @var array
- */
- protected static $_reset = false;
- /**
- * Engine instances keyed by configuration name.
- *
- * @var array
- */
- protected static $_engines = array();
- /**
- * Set the cache configuration to use. config() can
- * both create new configurations, return the settings for already configured
- * configurations.
- *
- * To create a new configuration, or to modify an existing configuration permanently:
- *
- * `Cache::config('my_config', array('engine' => 'File', 'path' => TMP));`
- *
- * If you need to modify a configuration temporarily, use Cache::set().
- * To get the settings for a configuration:
- *
- * `Cache::config('default');`
- *
- * There are 5 built-in caching engines:
- *
- * - `FileEngine` - Uses simple files to store content. Poor performance, but good for
- * storing large objects, or things that are not IO sensitive.
- * - `ApcEngine` - Uses the APC object cache, one of the fastest caching engines.
- * - `MemcacheEngine` - Uses the PECL::Memcache extension and Memcached for storage.
- * Fast reads/writes, and benefits from memcache being distributed.
- * - `XcacheEngine` - Uses the Xcache extension, an alternative to APC.
- * - `WincacheEngine` - Uses Windows Cache Extension for PHP. Supports wincache 1.1.0 and higher.
- *
- * 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 another 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 $settings Optional associative array of settings passed to the engine
- * @return array(engine, settings) on success, false on failure
- * @throws CacheException
- */
- public static function config($name = null, $settings = array()) {
- if (is_array($name)) {
- $settings = $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[$name]['engine'];
- if (!isset(self::$_engines[$name])) {
- self::_buildEngine($name);
- $settings = self::$_config[$name] = self::settings($name);
- } elseif ($settings = self::set(self::$_config[$name], null, $name)) {
- self::$_config[$name] = $settings;
- }
- return compact('engine', 'settings');
- }
- /**
- * Finds and builds the instance of the required engine class.
- *
- * @param string $name Name of the config array that needs an engine instance built
- * @return boolean
- * @throws CacheException
- */
- protected static function _buildEngine($name) {
- $config = self::$_config[$name];
- list($plugin, $class) = pluginSplit($config['engine'], true);
- $cacheClass = $class . 'Engine';
- App::uses($cacheClass, $plugin . 'Cache/Engine');
- if (!class_exists($cacheClass)) {
- return false;
- }
- $cacheClass = $class . 'Engine';
- if (!is_subclass_of($cacheClass, 'CacheEngine')) {
- throw new CacheException(__d('cake_dev', 'Cache engines must use CacheEngine as a base class.'));
- }
- self::$_engines[$name] = new $cacheClass();
- if (self::$_engines[$name]->init($config)) {
- if (self::$_engines[$name]->settings['probability'] && time() % self::$_engines[$name]->settings['probability'] === 0) {
- self::$_engines[$name]->gc();
- }
- return true;
- }
- return false;
- }
- /**
- * Returns an array containing the currently configured Cache settings.
- *
- * @return array Array of configured Cache config names.
- */
- public static function configured() {
- 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 $name A currently configured cache config you wish to remove.
- * @return boolean success of the removal, returns false when the config does not exist.
- */
- public static function drop($name) {
- if (!isset(self::$_config[$name])) {
- return false;
- }
- unset(self::$_config[$name], self::$_engines[$name]);
- return true;
- }
- /**
- * Temporarily change the settings on a cache config. The settings will persist for the next write
- * operation (write, decrement, increment, clear). Any reads that are done before the write, will
- * use the modified settings. If `$settings` is empty, the settings will be reset to the
- * original configuration.
- *
- * Can be called with 2 or 3 parameters. To set multiple values at once.
- *
- * `Cache::set(array('duration' => '+30 minutes'), 'my_config');`
- *
- * Or to set one value.
- *
- * `Cache::set('duration', '+30 minutes', 'my_config');`
- *
- * To reset a config back to the originally configured values.
- *
- * `Cache::set(null, 'my_config');`
- *
- * @param mixed $settings Optional string for simple name-value pair or array
- * @param string $value Optional for a simple name-value pair
- * @param string $config The configuration name you are changing. Defaults to 'default'
- * @return array Array of settings.
- */
- public static function set($settings = array(), $value = null, $config = 'default') {
- if (is_array($settings) && $value !== null) {
- $config = $value;
- }
- if (!isset(self::$_config[$config]) || !isset(self::$_engines[$config])) {
- return false;
- }
- if (!empty($settings)) {
- self::$_reset = true;
- }
- if (self::$_reset === true) {
- if (empty($settings)) {
- self::$_reset = false;
- $settings = self::$_config[$config];
- } else {
- if (is_string($settings) && $value !== null) {
- $settings = array($settings => $value);
- }
- $settings = array_merge(self::$_config[$config], $settings);
- if (isset($settings['duration']) && !is_numeric($settings['duration'])) {
- $settings['duration'] = strtotime($settings['duration']) - time();
- }
- }
- self::$_engines[$config]->settings = $settings;
- }
- return self::settings($config);
- }
- /**
- * Garbage collection
- *
- * Permanently remove all expired and deleted data
- *
- * @param string $config The config name you wish to have garbage collected. Defaults to 'default'
- * @return void
- */
- public static function gc($config = 'default') {
- self::$_engines[$config]->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 $config Optional string configuration name to write to. Defaults to 'default'
- * @return boolean True if the data was successfully cached, false on failure
- */
- public static function write($key, $value, $config = 'default') {
- $settings = self::settings($config);
- if (empty($settings)) {
- return false;
- }
- if (!self::isInitialized($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(null, $config);
- if ($success === false && $value !== '') {
- trigger_error(
- __d('cake_dev',
- "%s cache was unable to write '%s' to %s cache",
- $config,
- $key,
- self::$_engines[$config]->settings['engine']
- ),
- E_USER_WARNING
- );
- }
- 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 $config optional name of the configuration to use. Defaults to 'default'
- * @return mixed The cached data, or false if the data doesn't exist, has expired, or if there was an error fetching it
- */
- public static function read($key, $config = 'default') {
- $settings = self::settings($config);
- if (empty($settings)) {
- return false;
- }
- if (!self::isInitialized($config)) {
- return false;
- }
- $key = self::$_engines[$config]->key($key);
- if (!$key) {
- return false;
- }
- return self::$_engines[$config]->read($settings['prefix'] . $key);
- }
- /**
- * 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 $config Optional string configuration name. Defaults to 'default'
- * @return mixed new value, or false if the data doesn't exist, is not integer,
- * or if there was an error fetching it.
- */
- public static function increment($key, $offset = 1, $config = 'default') {
- $settings = self::settings($config);
- if (empty($settings)) {
- return false;
- }
- if (!self::isInitialized($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(null, $config);
- 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 subtract
- * @param string $config Optional string configuration name. Defaults to 'default'
- * @return mixed new value, or false if the data doesn't exist, is not integer,
- * or if there was an error fetching it
- */
- public static function decrement($key, $offset = 1, $config = 'default') {
- $settings = self::settings($config);
- if (empty($settings)) {
- return false;
- }
- if (!self::isInitialized($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(null, $config);
- return $success;
- }
- /**
- * Delete a key from the cache.
- *
- * ### 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 $config name of the configuration to use. Defaults to 'default'
- * @return boolean True if the value was successfully deleted, false if it didn't exist or couldn't be removed
- */
- public static function delete($key, $config = 'default') {
- $settings = self::settings($config);
- if (empty($settings)) {
- return false;
- }
- if (!self::isInitialized($config)) {
- return false;
- }
- $key = self::$_engines[$config]->key($key);
- if (!$key) {
- return false;
- }
- $success = self::$_engines[$config]->delete($settings['prefix'] . $key);
- self::set(null, $config);
- return $success;
- }
- /**
- * Delete all keys from the cache.
- *
- * @param boolean $check if true will check expiration, otherwise delete all
- * @param string $config name of the configuration to use. Defaults to 'default'
- * @return boolean True if the cache was successfully cleared, false otherwise
- */
- public static function clear($check = false, $config = 'default') {
- if (!self::isInitialized($config)) {
- return false;
- }
- $success = self::$_engines[$config]->clear($check);
- self::set(null, $config);
- return $success;
- }
- /**
- * Check if Cache has initialized a working config for the given name.
- *
- * @param string $config name of the configuration to use. Defaults to 'default'
- * @return boolean Whether or not the config name has been initialized.
- */
- public static function isInitialized($config = 'default') {
- if (Configure::read('Cache.disable')) {
- return false;
- }
- return isset(self::$_engines[$config]);
- }
- /**
- * Return the settings for the named cache engine.
- *
- * @param string $name Name of the configuration to get settings for. Defaults to 'default'
- * @return array list of settings for this engine
- * @see Cache::config()
- */
- public static function settings($name = 'default') {
- if (!empty(self::$_engines[$name])) {
- return self::$_engines[$name]->settings();
- }
- return array();
- }
- }
- /**
- * Storage engine for CakePHP caching
- *
- * @package Cake.Cache
- */
- abstract class CacheEngine {
- /**
- * Settings of current engine instance
- *
- * @var array
- */
- public $settings = array();
- /**
- * Initialize the cache engine
- *
- * Called automatically by the cache frontend
- *
- * @param array $settings Associative array of parameters for the engine
- * @return boolean True if the engine has been successfully initialized, false if not
- */
- public function init($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
- * @return void
- */
- 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 $duration How long to cache for.
- * @return boolean True if the data was successfully cached, false on failure
- */
- abstract public function write($key, $value, $duration);
- /**
- * Read a key from the cache
- *
- * @param string $key Identifier for the data
- * @return mixed The cached data, or false if the data doesn't exist, has expired, or if there was an error fetching it
- */
- abstract public function read($key);
- /**
- * Increment a number under the key and return incremented value
- *
- * @param string $key Identifier for the data
- * @param integer $offset How much to add
- * @return New incremented value, false otherwise
- */
- abstract public function increment($key, $offset = 1);
- /**
- * Decrement a number under the key and return decremented value
- *
- * @param string $key Identifier for the data
- * @param integer $offset How much to subtract
- * @return New incremented value, false otherwise
- */
- abstract public function decrement($key, $offset = 1);
- /**
- * Delete a key from the cache
- *
- * @param string $key Identifier for the data
- * @return boolean True if the value was successfully deleted, false if it didn't exist or couldn't be removed
- */
- abstract public function delete($key);
- /**
- * Delete all keys from the cache
- *
- * @param boolean $check if true will check expiration, otherwise delete all
- * @return boolean True if the cache was successfully cleared, false otherwise
- */
- abstract public function clear($check);
- /**
- * Cache Engine settings
- *
- * @return array settings
- */
- 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 $key or false
- */
- public function key($key) {
- if (empty($key)) {
- return false;
- }
- $key = Inflector::underscore(str_replace(array(DS, '/', '.'), '_', strval($key)));
- return $key;
- }
- }