/**
* Get singletonian instance of this class
*
* @return Ai1ec_Shutdown_Utility Singletonian instance of this class
*/
public static function instance()
{
if (!self::$_instance instanceof self) {
self::$_instance = new self();
}
return self::$_instance;
}
/**
* Constructor
*
* Read configured hooks and frequencies from database
*
* @return void Constructor does not return
*/
protected function __construct()
{
$defaults = array('hooks' => array(), 'freqs' => array(), 'version' => '1.11');
$this->_updated = false;
$this->_configuration = Ai1ec_Meta::get_option(self::OPTION_NAME, $defaults);
$this->_configuration = array_merge($defaults, $this->_configuration);
$this->install_default_schedules();
Ai1ec_Shutdown_Utility::instance()->register(array($this, 'shutdown'));
add_filter('ai1ec_settings_initiated', array($this, 'settings_initiated_hook'));
}