Package com.yahoo.messagebus

Class Sequencer

java.lang.Object
com.yahoo.messagebus.Sequencer
All Implemented Interfaces:
MessageHandler, ReplyHandler
public class Sequencer extends Object implements MessageHandler, ReplyHandler
Sequencing is implemented as a message handler that is configured in a source session in that session's chain of linked message handlers. Each message that carries a sequencing id is queued in an internal list of messages for that id, and messages are only sent when they are at the front of their list. When a reply arrives, the current front of the list is removed and the next message, if any, is sent.
Author:
Simon Thoresen Hult

  • Constructor Summary

    Constructors
    Constructor
    Description
    Sequencer(MessageHandler sender)
    Constructs a new sequencer on top of the given async sender.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    destroy()
    Sets the destroyed flag to true.
    void
    handleMessage(Message msg)
    All messages pass through this handler when being sent by the owning source session.
    void
    handleReply(Reply reply)
    Lookup the sequencing id of an incoming reply to pop the front of the corresponding queue, and then send the next message in line, if any.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Sequencer

      public Sequencer(MessageHandler sender)
      Constructs a new sequencer on top of the given async sender.
      Parameters:
      sender - The underlying sender.

  • Method Details

    • destroy

      public boolean destroy()
      Sets the destroyed flag to true. The very first time this method is called, it cleans up all its dependencies. Even if you retain a reference to this object, all of its content is allowed to be garbage collected.
      Returns:
      True if content existed and was destroyed.

    • handleMessage

      public void handleMessage(Message msg)
      All messages pass through this handler when being sent by the owning source session. In case the message has no sequencing-id, it is simply passed through to the next handler in the chain. Sequenced messages are sent only if there is no queue for their id, otherwise they are queued.
      Specified by:
      handleMessage in interface MessageHandler
      Parameters:
      msg - the message to send.

    • handleReply

      public void handleReply(Reply reply)
      Lookup the sequencing id of an incoming reply to pop the front of the corresponding queue, and then send the next message in line, if any.
      Specified by:
      handleReply in interface ReplyHandler
      Parameters:
      reply - The reply received.