ros_sugar.robot.bus

Feedback bus: fans decoded robot telemetry out to component consumers.

The plugin HOST (in the launcher process) decodes each telemetry packet once and publishes it on the FeedbackBus. Component consumers subscribe to the channels they need.

The bus carries bytes only; callers serialize ROS messages with rclpy.serialization and command payloads are already encoder output. The bus is symmetric. Either side may publish or subscribe.

Module Contents

Classes

BusHandle	Returned by FeedbackBus.subscribe; call unsubscribe to detach.
FeedbackBus	Bytes-only, channel-keyed pub/sub used between the plugin HOST and component consumers.
InProcessFeedbackBus	Direct in-process fan-out — used for multithreaded launch.
SocketFeedbackBus	Local abstract-namespace AF_UNIX fan-out - used for multiprocess launch.

API

class ros_sugar.robot.bus.BusHandle(unsubscribe: Callable[[], None])

Returned by FeedbackBus.subscribe; call unsubscribe to detach.

class ros_sugar.robot.bus.FeedbackBus

Bases: abc.ABC

Bytes-only, channel-keyed pub/sub used between the plugin HOST and component consumers.

abstractmethod start() → None

Bring the bus up on the HOST side (e.g. bind a server socket).

abstractmethod connect() → None

Attach to an already-started bus from a component process.

abstractmethod publish(channel: str, data: bytes) → None

Publish data on channel to every subscriber.

abstractmethod subscribe(channel: str, on_data: Callable[[bytes], None]) → ros_sugar.robot.bus.BusHandle

Register on_data to receive every payload published on channel.

abstractmethod close() → None

Tear the bus down and release all resources.

property endpoint: Optional[str]

Socket name for socket buses; None for in-process buses.

class ros_sugar.robot.bus.InProcessFeedbackBus

Bases: ros_sugar.robot.bus.FeedbackBus

Direct in-process fan-out — used for multithreaded launch.

start() → None

connect() → None

publish(channel: str, data: bytes) → None

subscribe(channel: str, on_data: Callable[[bytes], None]) → ros_sugar.robot.bus.BusHandle

close() → None

property endpoint: Optional[str]

class ros_sugar.robot.bus.SocketFeedbackBus(endpoint: Optional[str] = None)

Bases: ros_sugar.robot.bus.FeedbackBus

Local abstract-namespace AF_UNIX fan-out - used for multiprocess launch.

The HOST calls start, which binds an abstract-namespace Unix socket and exposes its name via endpoint. Each component process constructs a SocketFeedbackBus with that endpoint and calls connect.

property endpoint: Optional[str]

start() → None

connect() → None

publish(channel: str, data: bytes) → None

subscribe(channel: str, on_data: Callable[[bytes], None]) → ros_sugar.robot.bus.BusHandle

close() → None