StealthRelay

jsk_topic_tools/StealthRelay is a node/nodelet that subscribes to ~input topic and republishes all incoming data to ~output topic like topic_tools/Relay but only if ~monitor_topic topic is subscribed by any other nodes.

When ~input and ~monitor_topic topic name point to the same topic, it looks that this node subscribes ~input topic only when other nodes also subscribes it, which is equivalent to subscribing without incrementing subscription counter. ~monitor_topic can be set by rosparam and is set to ~input by default.

Subscribing Topics

• ~input (AnyMsg)

  Incoming topic to be relayed

Publishing Topics

• ~output (AnyMsg, same type as ~input)

  Outgoing topic to publish on

Parameters

• ~use_multithread_callback (bool, default: True)

  If true, initialize NodeHandle with multi threading.

• ~queue_size (int, default: 1)

  Queue size for subscription of the incoming topic.

• ~enable_monitor (bool, default: True)

  If enabled, monitoring feature is enabled, otherwise this nodelet behaves as same as Relay nodelet.

• ~monitor_topic (string, default: ~input)

  Topic name to monitor.

• ~monitor_rate (double, default: 1.0)

  Desired monitoring rate of subscribing messages of ~monitor_topic.