diff options
Diffstat (limited to 'kohana/libraries/Cache.php')
| -rw-r--r-- | kohana/libraries/Cache.php | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/kohana/libraries/Cache.php b/kohana/libraries/Cache.php new file mode 100644 index 00000000..4ad19cdc --- /dev/null +++ b/kohana/libraries/Cache.php @@ -0,0 +1,228 @@ +<?php defined('SYSPATH') or die('No direct script access.'); +/** + * 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. + * + * $Id$ + * + * @package Cache + * @author Kohana Team + * @copyright (c) 2007-2008 Kohana Team + * @license http://kohanaphp.com/license.html + */ +class Cache_Core { + + // For garbage collection + protected static $loaded; + + // Configuration + protected $config; + + // Driver object + protected $driver; + + /** + * Returns a singleton instance of Cache. + * + * @param array configuration + * @return Cache_Core + */ + public static function instance($config = array()) + { + static $obj; + + // Create the Cache instance + ($obj === NULL) and $obj = new Cache($config); + + return $obj; + } + + /** + * Loads the configured driver and validates it. + * + * @param array|string custom configuration or config group name + * @return void + */ + public function __construct($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 (self::$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 + $this->driver->delete_expired(); + + Kohana::log('debug', 'Cache: Expired caches deleted.'); + } + + // Cache has been loaded once + self::$loaded = TRUE; + } + } + + /** + * Fetches a cache by id. Non-string cache items are automatically + * unserialized before the cache is returned. NULL is returned when + * a cache item is not found. + * + * @param string cache id + * @return mixed cached data or NULL + */ + public function get($id) + { + // Change slashes to colons + $id = str_replace(array('/', '\\'), '=', $id); + + if ($data = $this->driver->get($id)) + { + if (substr($data, 0, 14) === '<{serialized}>') + { + // Data has been serialized, unserialize now + $data = unserialize(substr($data, 14)); + } + } + + return $data; + } + + /** + * Fetches all of the caches for a given tag. An empty array will be + * returned when no matching caches are found. + * + * @param string cache tag + * @return array all cache items matching the tag + */ + public function find($tag) + { + if ($ids = $this->driver->find($tag)) + { + $data = array(); + foreach ($ids as $id) + { + // Load each cache item and add it to the array + if (($cache = $this->get($id)) !== NULL) + { + $data[$id] = $cache; + } + } + + return $data; + } + + return array(); + } + + /** + * Set a cache item by id. Tags may also be added and a custom lifetime + * can be set. Non-string data is automatically serialized. + * + * @param string unique cache id + * @param mixed data to cache + * @param array tags for this item + * @param integer number of seconds until the cache expires + * @return boolean + */ + function set($id, $data, $tags = NULL, $lifetime = NULL) + { + if (is_resource($data)) + throw new Kohana_Exception('cache.resources'); + + // Change slashes to colons + $id = str_replace(array('/', '\\'), '=', $id); + + if ( ! is_string($data)) + { + // Serialize all non-string data, so that types can be preserved + $data = '<{serialized}>'.serialize($data); + } + + // Make sure that tags is an array + $tags = empty($tags) ? array() : (array) $tags; + + if ($lifetime === NULL) + { + // Get the default lifetime + $lifetime = $this->config['lifetime']; + } + + return $this->driver->set($id, $data, $tags, $lifetime); + } + + /** + * Delete a cache item by id. + * + * @param string cache id + * @return boolean + */ + public function delete($id) + { + // Change slashes to colons + $id = str_replace(array('/', '\\'), '=', $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(FALSE, $tag); + } + + /** + * Delete ALL cache items items. + * + * @return boolean + */ + public function delete_all() + { + return $this->driver->delete(TRUE); + } + +} // End Cache |