Abstract class **Phalcon\\Cache\\Backend** ========================================== *implements* :doc:`Phalcon\\Cache\\BackendInterface ` This class implements common functionality for backend adapters. A backend cache adapter may extend this class Methods ------- public **__construct** (:doc:`Phalcon\\Cache\\FrontendInterface ` $frontend, [*array* $options]) Phalcon\\Cache\\Backend constructor public *mixed* **start** (*int|string* $keyName, [*long* $lifetime]) Starts a cache. The $keyname allows to identify the created fragment public **stop** ([*boolean* $stopBuffer]) Stops the frontend without store any cached content public *mixed* **getFrontend** () Returns front-end instance adapter related to the back-end public *array* **getOptions** () Returns the backend options public *boolean* **isFresh** () Checks whether the last cache is fresh or cached public *boolean* **isStarted** () Checks whether the cache has starting buffering or not public **setLastKey** (*string* $lastKey) Sets the last key used in the cache public *string* **getLastKey** () Gets the last key stored by the cache public *int* **getLifetime** () Gets the last lifetime set abstract public *mixed* **get** (*int|string* $keyName, [*long* $lifetime]) inherited from Phalcon\\Cache\\BackendInterface Returns a cached content abstract public **save** ([*int|string* $keyName], [*string* $content], [*long* $lifetime], [*boolean* $stopBuffer]) inherited from Phalcon\\Cache\\BackendInterface Stores cached content into the file backend and stops the frontend abstract public *boolean* **delete** (*int|string* $keyName) inherited from Phalcon\\Cache\\BackendInterface Deletes a value from the cache by its key abstract public *array* **queryKeys** ([*string* $prefix]) inherited from Phalcon\\Cache\\BackendInterface Query the existing cached keys abstract public *boolean* **exists** ([*string* $keyName], [*long* $lifetime]) inherited from Phalcon\\Cache\\BackendInterface Checks if cache exists and it hasn't expired abstract public *boolean* **flush** () inherited from Phalcon\\Cache\\BackendInterface Immediately invalidates all existing items.