raccoon_transport.transport

Python transport wrapper around LCM with reliable and retained delivery helpers.

Attributes

logger

Classes

Transport

Main Python transport wrapper used by robotics applications and tests.

Module Contents

raccoon_transport.transport.logger
class raccoon_transport.transport.Transport(provider: str = '')

Main Python transport wrapper used by robotics applications and tests.

classmethod create(provider: str = '') → Transport

Construct a transport, optionally using an explicit LCM provider URL.

publish(channel: str, message, *, reliable: bool = False, retained: bool = False, retry_interval_ms: int = 100, max_retries: int = 10)

Publish an encoded LCM message with optional reliable and retained delivery.

Parameters:

  • channel – Destination channel name.

  • message – LCM message instance with an encode() method.

  • reliable – When True, wrap the payload in envelope_t and retransmit until acknowledged or retry attempts are exhausted.

  • retained – When True, cache the encoded payload so it can be replayed to future subscribers that request retained state.

  • retry_interval_ms – Delay between retransmissions in reliable mode.

  • max_retries – Maximum number of send attempts in reliable mode.

subscribe(channel: str, handler, *, reliable: bool = False, request_retained: bool = False)

Subscribe to a channel, optionally enabling reliable mode or retained replay.

Parameters:

  • channel – Channel to subscribe to.

  • handler – Callback passed to LCM for incoming payloads.

  • reliable – When True, subscribe to the internal reliable channel, acknowledge envelopes, deduplicate retransmissions, and forward the decoded payload to handler.

  • request_retained – When True, request any retained payload after the subscription is established.

Returns:

The subscription handle returned by lcm.LCM.subscribe.

spin_once(timeout_ms: int = 100) → int

Handle at most one pending LCM event and service reliable retries.

spin()

Block forever handling LCM traffic and reliable retransmissions.

close()

Unsubscribe all active handlers owned by this transport instance.