de.ipcon.db.event

Class DBManEventMuxer

java.lang.Object

de.ipcon.db.event.DBManEventMuxer

public class DBManEventMuxer
extends java.lang.Object

Every instance of DBManUserContextImpl (and nobody else anywhere) holds its own instance of a DBManEventMuxer. This instance is (only) used in the method DBManUserContextImpl.deliveryAllowed() which in turn is used by BackendCommandHandler.run() to determine if an event should be sent to the client that corresponds to the DBManUserContextImpl. Every such instance holds a list (ok, it's a Map actually ;-) of all the classes on the client side that registered (via DBManUserContextImpl.addSubscription()) for receiving DBManEvents. Every class subscribed this way must also have an associated DBManEventFilter(-subclass) here. As the events that arrive at the client side are distributed to the actual subscribed classes there by a DBManEventDemuxer, events are always sent to the client as soon as at least one subscriber's filter matches the event.

Constructor Summary

Constructors

Constructor and Description
DBManEventMuxer()

Method Summary

Modifier and Type	Method and Description
void	addSubscription(java.lang.String key, DBManEventFilter flt)
DBManEvent	applyFilters(DBManEvent evt) This method inspects if any of the current subscriptions of this DBManEventMuxer fit the passed DBManEvent evt and returns a cloned version of the event, possibly enriched with server-side calculated information and trimmed down to contain only the information the subscriber is interested in.
void	DBManEventSubscriptionManager()
void	removeSubscription(java.lang.String key)

Methods inherited from class java.lang.Object

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

Constructor Detail

DBManEventMuxer

public DBManEventMuxer()

Method Detail

DBManEventSubscriptionManager

public void DBManEventSubscriptionManager()

addSubscription

public void addSubscription(java.lang.String key,
                            DBManEventFilter flt)

removeSubscription

public void removeSubscription(java.lang.String key)

applyFilters

public DBManEvent applyFilters(DBManEvent evt)

This method inspects if any of the current subscriptions of this DBManEventMuxer fit the passed DBManEvent evt and returns a cloned version of the event, possibly enriched with server-side calculated information and trimmed down to contain only the information the subscriber is interested in. If a subscription was made without giving a filter the cloned event is returned as is. If a subscription was made providing a filter, it is checked if the type of the filter fits the type of the event and if the fits-method of the filter returns true. If so, the event is possibly enriched with server-side calculated information, if the filter provides rules for adding these. If no subscriber is interested in the event or if the cloned event is empty after trimming it for the subscriber, null is returned. Otherwise the cloned, trimmed down and possibly enriched event is returned.