com.espertech.esper.view.internal
Class PriorEventView

java.lang.Object
  com.espertech.esper.view.ViewSupport
      com.espertech.esper.view.internal.PriorEventView

All Implemented Interfaces:

EventCollection, View, Viewable, ViewDataVisitable, java.lang.Iterable<EventBean>

public class PriorEventView
extends ViewSupport
implements ViewDataVisitable

View that provides access to prior events posted by the parent view for use by 'prior' expression nodes.

Field Summary

protected ViewUpdatedCollection

buffer

Fields inherited from class com.espertech.esper.view.ViewSupport

EMPTY_VIEW_ARRAY

Constructor Summary

PriorEventView(ViewUpdatedCollection buffer)
Ctor.

Method Summary

ViewUpdatedCollection	getBuffer() Returns the underlying buffer used for access to prior events.
EventType	getEventType() Provides metadata information about the type of object the event collection contains.
java.util.Iterator<EventBean>	iterator() Allows iteration through all elements in this event collection.
void	setParent(Viewable parent) Called when the View is added to a Viewable object.
void	update(EventBean[] newData, EventBean[] oldData) Notify that data has been added or removed from the Viewable parent.
void	visitView(ViewDataVisitor viewDataVisitor)

Methods inherited from class com.espertech.esper.view.ViewSupport

addView, addView, dumpChildViews, dumpUpdateParams, dumpUpdateParams, findDescendent, findViewIndex, getParent, getViews, hasViews, removeAllViews, removeView, removeView, updateChildren, updateChildren

Methods inherited from class java.lang.Object

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

Field Detail

buffer

protected ViewUpdatedCollection buffer

Constructor Detail

PriorEventView

public PriorEventView(ViewUpdatedCollection buffer)

Ctor.

Parameters:

buffer - is handling the actual storage of events for use in the 'prior' expression

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.

Specified by:

update in interface View

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

setParent

public void setParent(Viewable parent)

Description copied from interface: View

Called when the View is added to a Viewable object.

Specified by:

setParent in interface View

Overrides:

setParent in class ViewSupport

Parameters:

parent - is the parent that this view is a child of

getBuffer

public ViewUpdatedCollection getBuffer()

Returns the underlying buffer used for access to prior events.

Returns:

buffer

getEventType

public EventType getEventType()

Description copied from interface: EventCollection

Provides metadata information about the type of object the event collection contains.

Specified by:

getEventType in interface EventCollection

Returns:

metadata for the objects in the collection

iterator

public java.util.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.

Specified by:

iterator in interface EventCollection

Specified by:

iterator in interface java.lang.Iterable<EventBean>

Returns:

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

visitView

public void visitView(ViewDataVisitor viewDataVisitor)

Specified by:

visitView in interface ViewDataVisitable