*/ interface CacheInterface { /** * Fetches a value from the pool or computes it if not found. * * On cache misses, a callback is called that should return the missing value. * This callback is given a PSR-6 CacheItemInterface instance corresponding to the * requested key, that could be used e.g. for expiration control. It could also * be an ItemInterface instance when its additional features are needed. * * @param string $key The key of the item to retrieve from the cache * @param callable|CallbackInterface $callback Should return the computed value for the given key/item * @param float|null $beta A float that, as it grows, controls the likeliness of triggering * early expiration. 0 disables it, INF forces immediate expiration. * The default (or providing null) is implementation dependent but should * typically be 1.0, which should provide optimal stampede protection. * See https://en.wikipedia.org/wiki/Cache_stampede#Probabilistic_early_expiration * @param array &$metadata The metadata of the cached item {@see ItemInterface::getMetadata()} * * @return mixed The value corresponding to the provided key * * @throws InvalidArgumentException When $key is not valid or when $beta is negative */ public function get(string $key, callable $callback, float $beta = null, array &$metadata = null); /** * Removes an item from the pool. * * @param string $key The key to delete * * @throws InvalidArgumentException When $key is not valid * * @return bool True if the item was successfully removed, false if there was any error */ public function delete(string $key): bool; }