com.espertech.esper.epl.subquery
Class SubselectAggregatorView

java.lang.Object
  extended by com.espertech.esper.view.ViewSupport
      extended by com.espertech.esper.epl.subquery.SubselectAggregatorView
All Implemented Interfaces:
EventCollection, View, Viewable, Iterable<EventBean>

public class SubselectAggregatorView
extends ViewSupport

View handling the insert and remove stream generated by a subselect for application to aggregation state.


Field Summary
 
Fields inherited from class com.espertech.esper.view.ViewSupport
parent
 
Constructor Summary
SubselectAggregatorView(AggregationService aggregationService, ExprNode optionalFilterExpr)
          Ctor.
 
Method Summary
 EventType getEventType()
          Provides metadata information about the type of object the event collection contains.
 Iterator<EventBean> iterator()
          Allows iteration through all elements in this event collection.
 void update(EventBean[] newData, EventBean[] oldData)
          Notify that data has been added or removed from the Viewable parent.
 
Methods inherited from class com.espertech.esper.view.ViewSupport
addView, dumpChildViews, dumpUpdateParams, dumpUpdateParams, findDescendent, getParent, getViews, hasViews, removeView, setParent, updateChildren, updateChildren
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SubselectAggregatorView

public SubselectAggregatorView(AggregationService aggregationService,
                               ExprNode optionalFilterExpr)
Ctor.

Parameters:
aggregationService - for aggregating
optionalFilterExpr - for filtering the view-posted events before aggregation
Method Detail

update

public void update(EventBean[] newData,
                   EventBean[] oldData)
Description copied from interface: View
Notify that data has been added or removed from the Viewable parent. The last object in the newData array of objects would be the newest object added to the parent view. The first object of the oldData array of objects would be the oldest object removed from the parent view. If the call to update contains new (inserted) data, then the first argument will be a non-empty list and the second will be empty. Similarly, if the call is a notification of deleted data, then the first argument will be empty and the second will be non-empty. Either the newData or oldData will be non-null. This method won't be called with both arguments being null, but either one could be null. The same is true for zero-length arrays. Either newData or oldData will be non-empty. If both are non-empty, then the update is a modification notification. When update() is called on a view by the parent object, the data in newData will be in the collection of the parent, and its data structures will be arranged to reflect that. The data in oldData will not be in the parent's data structures, and any access to the parent will indicate that that data is no longer there.

Parameters:
newData - is the new data that has been added to the parent view
oldData - is the old data that has been removed from the parent view

getEventType

public EventType getEventType()
Description copied from interface: EventCollection
Provides metadata information about the type of object the event collection contains.

Returns:
metadata for the objects in the collection

iterator

public Iterator<EventBean> iterator()
Description copied from interface: EventCollection
Allows iteration through all elements in this event collection. The iterator will return the elements in the collection in their natural order, or, if there is no natural ordering, in some unpredictable order.

Returns:
an iterator which will go through all current elements in the collection.

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