/**
* 判断延迟过期的键值理论上是否存在
* @param string $key 键名
* @return boolean 是否存在
*/
public function hasDE($key)
{
if ($this->driver->checkDriver()) {
return $this->driver->hasDE($key);
}
if ($this->driver->isFallback() && $this->type !== self::$config['fallback']) {
return $this->driver->backup()->hasDE($key);
}
return false;
}