FrostBus Reactor

The FrostBus is a central component in the Frost architecture that acts as a message router. It is responsible for managing the registration of different Frost components and ensuring that messages are delivered to their intended targets. It extends FrostDataModel, allowing it to have its own data model for tracking registered machines.

Core Functionalities

• Component Registration: The FrostBus listens for registration requests from other Frost components. When a component sends a REGISTER message, the bus adds it to a routing_map, which maps the component's name to its bus index.
• Message Routing: It overrides the _set_channel_out_port method to implement its routing logic. When it receives a message to send, it looks up the target in its routing_map and forwards the message to the correct output port connected to that target.
• Data Model Management: The bus maintains a data model that keeps track of the number of registered machines and information about each one, such as its index on the bus.

Code Snippets

Handling Registration Requests

This reaction processes registration requests from new components, adding them to the routing map and updating the data model.

reaction(message_filter.requests) -> channel_out {=
    for bank_index, message in message_filter.requests.value:
        if message.header.namespace != MsgNamespace.PROTOCOL or message.header.msg_name != ProtocolMsgName.REGISTER:
            continue

        if message.sender in self.routing_map:
            continue

        self.routing_map[message.sender] = bank_index

        # ... update data model with new machine info ...

        self.number_of_machines.value += 1

        # Send a response to acknowledge the registration
        response = FrostMessage(
            # ... create response message ...
        )
        self._set_channel_out_port([response], channel_out)
=}

Message Routing

This method contains the core routing logic. It looks up the message's target in the routing_map and sends the message to the corresponding output port.

method _set_channel_out_port(value, channel_out) {=
    for message in value:
        if message.target not in self.routing_map:
            self.logger.warning(f"Cannot route message {message} to unknown target {message.target}.")
            continue

        index = self.routing_map[message.target]
        self._set_output_port(message, channel_out[index])
=}