protected function init($mode = 0)
    {
        // initialize syslog
        if ($this->config->get('log_driver') == 'syslog') {
            $syslog_id       = $this->config->get('syslog_id', 'roundcube');
            $syslog_facility = $this->config->get('syslog_facility', LOG_USER);
            openlog($syslog_id, LOG_ODELAY, $syslog_facility);
        }

        // connect to database
        if ($mode & self::INIT_WITH_DB) {
            $this->get_dbh();
        }

        // create plugin API and load plugins
        if ($mode & self::INIT_WITH_PLUGINS) {
            $this->plugins = rcube_plugin_api::get_instance();
        }
    }