Using a cache * * * // foo is any name (try to be specific), and is used to get configuration * // & storage info * $cache = SS_Cache::factory('foo'); * * if (!($result = $cache->load($cachekey))) { * $result = caluate some how; * $cache->save($result); * } * * return $result; * * * Normally there's no need to remove things from the cache - the cache * backends clear out entries based on age & maximum allocated storage. If you * include the version of the object in the cache key, even object changes * don't need any invalidation. * *

Disabling cache in dev mode

* * * // _config.php * if (Director::isDev()) { * SS_Cache::set_cache_lifetime('any', -1, 100); * // * * *

Using memcached as a store

* * * // _config.php * SS_Cache::add_backend( * 'primary_memcached', * 'Memcached', * array( * 'host' => 'localhost', * 'port' => 11211, * 'persistent' => true, * 'weight' => 1, * 'timeout' => 5, * 'retry_interval' => 15, * 'status' => true, * 'failure_callback' => '' * ) * ); * * SS_Cache::pick_backend('primary_memcached', 'any', 10); * * // Aggregate needs a backend with tag support, which memcached doesn't * // provide * SS_Cache::pick_backend('default', 'aggregate', 20); * * *

Using APC as a store

* * * SS_Cache::add_backend('two-level', 'Two-Levels', array( * 'slow_backend' => 'File', * 'fast_backend' => 'Apc', * 'slow_backend_options' => array( * 'cache_dir' => TEMP_FOLDER . DIRECTORY_SEPARATOR . 'cache' * ) * )); * * // No need for special backend for aggregate - TwoLevels with a File slow * // backend supports tags * SS_Cache::pick_backend('two-level', 'Two-Levels', 10); * * *

Invalidate an element

* * * $cache = SS_Cache::factory('foo'); * $cache->remove($cachekey); * * *

Clear the cache

* * This clears the entire backend, not just this named cache partition. * * * $cache = SS_Cache::factory('foo'); * $cache->clean(Zend_Cache::CLEANING_MODE_ALL); * * * @package framework * @subpackage core */ class SS_Cache { /** * @var array $backends */ protected static $backends = array(); /** * @var array $backend_picks */ protected static $backend_picks = array(); /** * @var array $cache_lifetime */ protected static $cache_lifetime = array(); /** * Initialize the 'default' named cache backend. */ protected static function init(){ if (!isset(self::$backends['default'])) { $cachedir = TEMP_FOLDER . DIRECTORY_SEPARATOR . 'cache'; if (!is_dir($cachedir)) { mkdir($cachedir); } self::$backends['default'] = array( 'File', array( 'cache_dir' => $cachedir ) ); self::$cache_lifetime['default'] = array( 'lifetime' => 600, 'priority' => 1 ); } } /** * Add a new named cache backend. * * @see http://framework.zend.com/manual/en/zend.cache.html * * @param string $name The name of this backend as a freeform string * @param string $type The Zend_Cache backend ('File' or 'Sqlite' or ...) * @param array $options The Zend_Cache backend options * * @return none */ public static function add_backend($name, $type, $options = array()) { self::init(); self::$backends[$name] = array($type, $options); } /** * Pick a named cache backend for a particular named cache. * * The priority call with the highest number will be the actual backend * picked. A backend picked for a specific cache name will always be used * instead of 'any' if it exists, no matter the priority. * * @param string $name The name of the backend, as passed as the first argument to add_backend * @param string $for The name of the cache to pick this backend for (or 'any' for any backend) * @param integer $priority The priority of this pick * * @return none */ public static function pick_backend($name, $for, $priority = 1) { self::init(); $current = -1; if (isset(self::$backend_picks[$for])) { $current = self::$backend_picks[$for]['priority']; } if ($priority >= $current) { self::$backend_picks[$for] = array( 'name' => $name, 'priority' => $priority ); } } /** * Return the cache lifetime for a particular named cache. * * @param string $for * * @return string */ public static function get_cache_lifetime($for) { if(isset(self::$cache_lifetime[$for])) { return self::$cache_lifetime[$for]; } return null; } /** * Set the cache lifetime for a particular named cache * * @param string $for The name of the cache to set this lifetime for (or 'any' for all backends) * @param integer $lifetime The lifetime of an item of the cache, in seconds, or -1 to disable caching * @param integer $priority The priority. The highest priority setting is used. Unlike backends, 'any' is not * special in terms of priority. */ public static function set_cache_lifetime($for, $lifetime=600, $priority=1) { self::init(); $current = -1; if (isset(self::$cache_lifetime[$for])) { $current = self::$cache_lifetime[$for]['priority']; } if ($priority >= $current) { self::$cache_lifetime[$for] = array( 'lifetime' => $lifetime, 'priority' => $priority ); } } /** * Build a cache object. * * @see http://framework.zend.com/manual/en/zend.cache.html * * @param string $for The name of the cache to build * @param string $frontend (optional) The type of Zend_Cache frontend * @param array $frontendOptions (optional) Any frontend options to use. * * @return Zend_Cache_Frontend The cache object */ public static function factory($for, $frontend='Output', $frontendOptions=null) { self::init(); $backend_name = 'default'; $backend_priority = -1; $cache_lifetime = self::$cache_lifetime['default']['lifetime']; $lifetime_priority = -1; foreach(array('any', $for) as $name) { if(isset(self::$backend_picks[$name])) { if(self::$backend_picks[$name]['priority'] > $backend_priority) { $backend_name = self::$backend_picks[$name]['name']; $backend_priority = self::$backend_picks[$name]['priority']; } } if (isset(self::$cache_lifetime[$name])) { if(self::$cache_lifetime[$name]['priority'] > $lifetime_priority) { $cache_lifetime = self::$cache_lifetime[$name]['lifetime']; $lifetime_priority = self::$cache_lifetime[$name]['priority']; } } } $backend = self::$backends[$backend_name]; $basicOptions = array('cache_id_prefix' => $for); if ($cache_lifetime >= 0) { $basicOptions['lifetime'] = $cache_lifetime; } else { $basicOptions['caching'] = false; } $frontendOptions = $frontendOptions ? array_merge($basicOptions, $frontendOptions) : $basicOptions; require_once 'Zend/Cache.php'; return Zend_Cache::factory( $frontend, $backend[0], $frontendOptions, $backend[1] ); } }