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Class edu.utah.janos.antsr.route.DynamicRouteApp
java.lang.Object
   |
   +----edu.utah.janos.antsr.core.Entity
           |
           +----edu.utah.janos.antsr.core.Application
                   |
                   +----edu.utah.janos.antsr.route.DynamicRouteApp

  Summary

public class  DynamicRouteApp
     extends edu.utah.janos.antsr.core.Application
{
          // Fields 7
     public static final int APP_PORT;
     private static final int MAXROUTESPERUPDATE;
     private static final String[] defaults;
     private final DynamicRouteEvents events;
     private Node node;
     private boolean suppressTriggerEvents;
     private DynamicRouteTable table;

          // Constructors 1
     public DynamicRouteApp();

          // Methods 14
     private void clearChangeFlags();
     private void expireEntries(DynamicRouteEvent);
     private void gcEntries(DynamicRouteEvent);
     private void initApp();
     private void initEvents();
     boolean newRouteInfo(int, int, int, String, long);
     public void receive(Capsule);
     void scheduleTrigger(long);
     private void sendRouteMessages(int);
     private void sendRouteWorker(DynamicRouteEntry, int);
     private void sendUpdate(DynamicRouteEntry, Vector);
     public void setArgs(KeyArgs) throws InvalidKeyArgsException;
     public void start();
     void suppressTriggerEvents(boolean);
}

The "app" that maintains a node's dynamic routing tables.

This is really just an app so it can justify sending capsules off without priming them off some other capsule. (All this code used to be part of DynamicRouteTable.)

Understands the default '-port' argument that all apps grok.

Author:
Janos Ministry of Development , David Wetherall




  Fields

· APP_PORT

Summary  |  Top

   public static final int APP_PORT


· defaults

Summary  |  Top
   private static final String[] defaults


· MAXROUTESPERUPDATE

Summary  |  Top
   private static final int MAXROUTESPERUPDATE

Maximum number of route updates to stuff into a single RouteUpdateCapsule. (Each update costs 5 bytes).


· table

Summary  |  Top
   private DynamicRouteTable table

The table this app is keeping up to date.


· node

Summary  |  Top
   private Node node

The node this table is maintained on.


· suppressTriggerEvents

Summary  |  Top
   private boolean suppressTriggerEvents

Used for suppressing triggered updates. Triggered updates are scheduled when the routing table is changed. Once a triggered update is scheduled, futher updates are suppressed until the trigger update is executed.


· events

Summary  |  Top
   private final DynamicRouteEvents events

The queue of timers and events that cause updates.


  Constructors

· DynamicRouteApp

Summary  |  Top

   public DynamicRouteApp() 

App constructors can't do anything useful. Ideally, I would like to set this.node and this.table, but I can't because the node hasn't been plugged into this app yet, and I need to node to get the table...



  Methods

· setArgs

Summary  |  Top
   public void setArgs(KeyArgs k)  throws InvalidKeyArgsException

Parse command line arguments.

See the class description for a list of the arguments and their meaning.

Overrides:
setArgs in class Application


· initEvents

Summary  |  Top
   private void initEvents() 

Initialize the event queue.



· initApp

Summary  |  Top
   private void initApp() 

Do initialization of the App.

XXX one-time function.



· start

Summary  |  Top
   public void start() 

The active route table logic.

Harmless if invoked on a static table.

Overrides:
start in class Application


· expireEntries

Summary  |  Top
   private void expireEntries(DynamicRouteEvent e) 

Walks all routes and moves expired routes into the gcPool.



· gcEntries

Summary  |  Top
   private void gcEntries(DynamicRouteEvent e) 

Delete all routes in the gcPool that have expired. Such routes are lost for all time.



· clearChangeFlags

Summary  |  Top
   private void clearChangeFlags() 

Mark all routes as 'unchanged'.



· sendUpdate

Summary  |  Top
   private void sendUpdate(DynamicRouteEntry g, 
                           Vector r) 

Send a route update to the given node.

XXX this is completely out of synch with the new world order.



· sendRouteWorker

Summary  |  Top
   private void sendRouteWorker(DynamicRouteEntry gatewayRoute, 
                                int cause) 

Send a message to a host about a route. The given host should be a gateway host for this node.



· sendRouteMessages

Summary  |  Top
   private void sendRouteMessages(int cause) 

Send a message to each gateway and to host which has a cost of "1" to reach. For each gateway send a long list of route entries.

XXX this is O(N * N) when N is the *number of routes*!

Parameter Description
cause the reason this was invoked (Trigger or periodic).



· receive

Summary  |  Top
   public void receive(Capsule unknownCap) 

Receive and process RouteUpdateCapsule. RouteUpdateCapsules contain zero or more route update records. Each "record" consists of a destination and a "distance" to that destination.

Parameter Description
unknownCap the RouteUpdateCapsule.

Overrides:
receive in class Application


· newRouteInfo

Summary  |  Top
   boolean newRouteInfo(int dest, 
                        int dist, 
                        int gw, 
                        String gwPhysAddr, 
                        long now) 

Provide new information for a single route. If the info is useful, update the route table. It is the caller's responsibility to schedule a trigger update if there are changes to the route table.

Invoked by exclusivly by RouteUpdateCapsule.evalutate.

Parameter Description
dest the active address of the destination to update a route to
dist the distance to that node from the gateway
gw the active address of the gateway (the "next hop" to dest)
gwPhysAddr the physical address of the gateway
now what time is it my dear?

Returns:
true if a change was made; false if not.

See Also: RouteUpdateCapsule



· suppressTriggerEvents

Summary  |  Top
   void suppressTriggerEvents(boolean doit) 

Suppress scheduling of further trigger events. Or don't.



· scheduleTrigger

Summary  |  Top
   void scheduleTrigger(long when) 

Schedule a trigger event for some time after 'when'. If triggers are surpressed (because one has already been scheduled but not executed) the request is dropped on the floor.

Invoked in here and by RouteUpdateCapsule.



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