Configuration state is managed by the Config class. An instance of this represents a configuration of TxnBox. The instance is similar to the global data for a process - data that is tied to a configuration in general and not to any particular configuration element is stored here. An instance of Config acts as the “context” for parsing configuration.
Directives interact heavily with this class. The :cpp:class::Directive::FactoryInfo contains the static information about a directive. In addition, it has an “index” field which is used to track which directives are used in a configuration.
To make a directive available it must register by using the Config::define method.