Horde_Cache_Storage_Base::exists PHP Метод

Checks if a given key exists in the cache, valid for the given lifetime.

abstract public exists ( string $key, integer $lifetime ) : boolean
$key	string	Cache key to check.
$lifetime	integer	Lifetime of the key in seconds.
Результат	boolean	Existence.

    public abstract function exists($key, $lifetime = 0);

Horde_Cache_Storage_Base