# Class **Phalcon\Cache\Backend\File**[](# "永久链接至标题") *extends* abstract class [*Phalcon\Cache\Backend*](#) *implements*[*Phalcon\Cache\BackendInterface*](#) Allows to cache output fragments using a file backend ~~~ <?php //Cache the file for 2 days $frontendOptions = array( 'lifetime' => 172800 ); //Create a output cache $frontCache = \Phalcon\Cache\Frontend\Output($frontOptions); //Set the cache directory $backendOptions = array( 'cacheDir' => '../app/cache/' ); //Create the File backend $cache = new \Phalcon\Cache\Backend\File($frontCache, $backendOptions); $content = $cache->start('my-cache'); if ($content === null) { echo '<h1>', time(), '</h1>'; $cache->save(); } else { echo $content; } ~~~ ### Methods[](# "永久链接至标题") public **__construct** ([*Phalcon\Cache\FrontendInterface*](#) $frontend, [*array* $options]) Phalcon\Cache\Backend\File constructor public *mixed***get** (*int|string* $keyName, [*int* $lifetime]) Returns a cached content public **save** ([*int|string* $keyName], [*string* $content], [*int* $lifetime], [*boolean* $stopBuffer]) Stores cached content into the file backend and stops the frontend public *boolean***delete** (*int|string* $keyName) Deletes a value from the cache by its key public *array***queryKeys** ([*string|int* $prefix]) Query the existing cached keys public *boolean***exists** ([*string|int* $keyName], [*int* $lifetime]) Checks if cache exists and it isn't expired public *mixed***increment** ([*string|int* $keyName], [*int* $value]) Increment of a given key, by number $value public *mixed***decrement** ([*string|int* $keyName], [*int* $value]) Decrement of a given key, by number $value public **flush** () Immediately invalidates all existing items. public **getKey** (*unknown* $key) Return a file-system safe identifier for a given key public *this***useSafeKey** (*unknown* $useSafeKey) Set whether to use the safekey or not public **getFrontend** () inherited from Phalcon\Cache\Backend ... public **setFrontend** (*unknown* $frontend) inherited from Phalcon\Cache\Backend ... public **getOptions** () inherited from Phalcon\Cache\Backend ... public **setOptions** (*unknown* $options) inherited from Phalcon\Cache\Backend ... public **getLastKey** () inherited from Phalcon\Cache\Backend ... public **setLastKey** (*unknown* $lastKey) inherited from Phalcon\Cache\Backend ... public *mixed***start** (*int|string* $keyName, [*int* $lifetime]) inherited from Phalcon\Cache\Backend Starts a cache. The keyname allows to identify the created fragment public **stop** ([*unknown* $stopBuffer]) inherited from Phalcon\Cache\Backend Stops the frontend without store any cached content public **isFresh** () inherited from Phalcon\Cache\Backend Checks whether the last cache is fresh or cached public **isStarted** () inherited from Phalcon\Cache\Backend Checks whether the cache has starting buffering or not public *int***getLifetime** () inherited from Phalcon\Cache\Backend Gets the last lifetime set | - [索引](# "总目录") - [下一页](# "Class Phalcon\Cache\Backend\Libmemcached") | - [上一页](# "Class Phalcon\Cache\Backend\Apc") | - [API Indice](#) »