Package org.lsst.ccs.messaging

Interface BusMessagingLayer

All Superinterfaces:
AutoCloseable, Closeable, MessagingLayer
All Known Implementing Classes:
JGroupsBusMessagingLayer, JMSBusMessagingLayer
public interface BusMessagingLayer extends Closeable, MessagingLayer
Interface defining the access to the Transport Layer of Buses
Author:
bamade TODO: create an accept URI

  • Method Details

    • parseDestination

      static String parseDestination(String destination)
      utility method: parse the destination string in Commands. extracts the agent name from a complete destination
      Parameters:
      destination - the complete destination (e.g : "sft/carousel")
      Returns:
      the agent name (e.g : "sft")

    • register

      void register(String agentName, Bus... buses) throws IOException, DuplicateAgentNameException
      Creates low level communication entry points for a subsystem. Abstract vision is that there is a different entry point for each bus/topic.
      Parameters:
      agentName - name of the sending/receiving point as will be known by transport null or empty string means that the local agent will receive all messages (whatever the destination of the message is : "anonymous agent") if an agent with same name is already locally registered for these buses nothing happens (the call is idempotent), but if another agent has the same name on the network a DuplicateBusNameException may be fired (this is an optional behaviour) but this exception is reported only to the corresponding BusMembershipListener
      buses - list of buses we want to connect to, if empty connects to all buses
      Throws:
      IOException - if connection impossible,
      DuplicateAgentNameException

    • closeFor

      void closeFor(String agentName, Bus... buses)
      close entry points for a bus for an agent. calls should be idempotent.
      Parameters:
      agentName - (if empty voids the "anonymous" agent capabilities
      buses - if empty all registered buses for the agent will be closed
      Throws:
      IllegalArgumentException - if you do not "own" the agent corresponding to the name.

    • getRegisteredLocalAgents

      Set<String> getRegisteredLocalAgents(Bus... buses)
      Get the list of local agents currently connected to the buses.
      Parameters:
      buses - The buses for which we are seeking the connected agents. If empty it will report agents connected to all buses.
      Returns:
      The List of registered buses.
      Throws:
      IOException

    • getRegisteredLocalAgents

      default Set<String> getRegisteredLocalAgents()
      Get the list of local agents currently connected to all buses.
      Returns:
      The List of registered buses.
      Throws:
      IOException

    • close

      void close() throws IOException
      Close the Transport Layer. Subsequent method calls will have no effect.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Throws:
      IOException

    • addMessageListener

      void addMessageListener(String agentName, BusMessageForwarder forwarder, Bus... buses)
      Sets up callback configuration for a topic and subsystem. There could be multiple Forwarder for a given bus. All callbacks are supposed to be multithreaded
      Parameters:
      agentName - if empty adds a forwarder to "anonymous" agent that receives all messages
      forwarder - code that handles the incoming messages
      buses - if empty the forwarder listens to all buses.
      Throws:
      IllegalArgumentException - if the subsystem is not registered to one of the buses or if forwarder is null

    • removeMessageListener

      void removeMessageListener(String agentName, BusMessageForwarder forwarder, Bus... buses)
      Removes a message listener from the forwarder list.
      Parameters:
      agentName -
      forwarder -
      buses - if empty forwarder is removed from all buses
      Throws:
      IllegalArgumentException - if forwarder is null (but no exception if the subsystem is not registered, or forwarder not present)