FindAndRemove Snippet

findAndRemoveSnippet.scala

  def dequeue: MessageInvocation = withErrorHandling {
    /** 
     * Retrieves first item in natural order (oldest first, assuming no modification/move)
     * Waits 3 seconds for now for a message, else pops back out.
     * TODO - How do we handle fetch, but sleep if nothing is in there cleanly?
     * TODO - Should we have a specific query in place? Which way do we sort? 
     * TODO - Error handling version!
     */
    val msgInvocation = new DefaultPromise[MessageInvocation](3000)
    db.findAndRemove(collName)(Document.empty) { msg: MongoDurableMessage => 
      EventHandler.debug(this, 
        "\nDEQUEUING message in mongo-based mailbox [%s]".format(msg))
      msgInvocation.completeWithResult(msg.messageInvocation())
      EventHandler.debug(this, 
        "\nDEQUEUING messageInvocation in mongo-based mailbox [%s]".format(msgInvocation))
    }
    msgInvocation.get 
  }