diff options
Diffstat (limited to 'system/libraries/Cache.php')
| -rw-r--r-- | system/libraries/Cache.php | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/system/libraries/Cache.php b/system/libraries/Cache.php new file mode 100644 index 00000000..8a02a905 --- /dev/null +++ b/system/libraries/Cache.php @@ -0,0 +1,208 @@ +<?php defined('SYSPATH') OR die('No direct access allowed.'); +/** + * Provides a driver-based interface for finding, creating, and deleting cached + * resources. Caches are identified by a unique string. Tagging of caches is + * also supported, and caches can be found and deleted by id or tag. + * + * $Id: Cache.php 4321 2009-05-04 01:39:44Z kiall $ + * + * @package Cache + * @author Kohana Team + * @copyright (c) 2007-2008 Kohana Team + * @license http://kohanaphp.com/license.html + */ +class Cache_Core { + + protected static $instances = array(); + + // For garbage collection + protected static $loaded; + + // Configuration + protected $config; + + // Driver object + protected $driver; + + /** + * Returns a singleton instance of Cache. + * + * @param string configuration + * @return Cache_Core + */ + public static function & instance($config = FALSE) + { + if ( ! isset(Cache::$instances[$config])) + { + // Create a new instance + Cache::$instances[$config] = new Cache($config); + } + + return Cache::$instances[$config]; + } + + /** + * Loads the configured driver and validates it. + * + * @param array|string custom configuration or config group name + * @return void + */ + public function __construct($config = FALSE) + { + if (is_string($config)) + { + $name = $config; + + // Test the config group name + if (($config = Kohana::config('cache.'.$config)) === NULL) + throw new Kohana_Exception('cache.undefined_group', $name); + } + + if (is_array($config)) + { + // Append the default configuration options + $config += Kohana::config('cache.default'); + } + else + { + // Load the default group + $config = Kohana::config('cache.default'); + } + + // Cache the config in the object + $this->config = $config; + + // Set driver name + $driver = 'Cache_'.ucfirst($this->config['driver']).'_Driver'; + + // Load the driver + if ( ! Kohana::auto_load($driver)) + throw new Kohana_Exception('core.driver_not_found', $this->config['driver'], get_class($this)); + + // Initialize the driver + $this->driver = new $driver($this->config['params']); + + // Validate the driver + if ( ! ($this->driver instanceof Cache_Driver)) + throw new Kohana_Exception('core.driver_implements', $this->config['driver'], get_class($this), 'Cache_Driver'); + + Kohana::log('debug', 'Cache Library initialized'); + + if (Cache::$loaded !== TRUE) + { + $this->config['requests'] = (int) $this->config['requests']; + + if ($this->config['requests'] > 0 AND mt_rand(1, $this->config['requests']) === 1) + { + // Do garbage collection + $this->driver->delete_expired(); + + Kohana::log('debug', 'Cache: Expired caches deleted.'); + } + + // Cache has been loaded once + Cache::$loaded = TRUE; + } + } + + /** + * Fetches a cache by id. NULL is returned when a cache item is not found. + * + * @param string cache id + * @return mixed cached data or NULL + */ + public function get($id) + { + // Sanitize the ID + $id = $this->sanitize_id($id); + + return $this->driver->get($id); + } + + /** + * Fetches all of the caches for a given tag. An empty array will be + * returned when no matching caches are found. + * + * @param string cache tag + * @return array all cache items matching the tag + */ + public function find($tag) + { + return $this->driver->find($tag); + } + + /** + * Set a cache item by id. Tags may also be added and a custom lifetime + * can be set. Non-string data is automatically serialized. + * + * @param string unique cache id + * @param mixed data to cache + * @param array|string tags for this item + * @param integer number of seconds until the cache expires + * @return boolean + */ + function set($id, $data, $tags = NULL, $lifetime = NULL) + { + if (is_resource($data)) + throw new Kohana_Exception('cache.resources'); + + // Sanitize the ID + $id = $this->sanitize_id($id); + + if ($lifetime === NULL) + { + // Get the default lifetime + $lifetime = $this->config['lifetime']; + } + + return $this->driver->set($id, $data, (array) $tags, $lifetime); + } + + /** + * Delete a cache item by id. + * + * @param string cache id + * @return boolean + */ + public function delete($id) + { + // Sanitize the ID + $id = $this->sanitize_id($id); + + return $this->driver->delete($id); + } + + /** + * Delete all cache items with a given tag. + * + * @param string cache tag name + * @return boolean + */ + public function delete_tag($tag) + { + return $this->driver->delete($tag, TRUE); + } + + /** + * Delete ALL cache items items. + * + * @return boolean + */ + public function delete_all() + { + return $this->driver->delete(TRUE); + } + + /** + * Replaces troublesome characters with underscores. + * + * @param string cache id + * @return string + */ + protected function sanitize_id($id) + { + // Change slashes and spaces to underscores + return str_replace(array('/', '\\', ' '), '_', $id); + } + +} // End Cache |