com.espertech.esper.view.std
Class SizeView

java.lang.Object
  extended by com.espertech.esper.view.ViewSupport
      extended by com.espertech.esper.view.std.SizeView
All Implemented Interfaces:
CloneableView, EventCollection, View, Viewable, java.lang.Iterable<EventBean>

public class SizeView
extends ViewSupport
implements CloneableView

This view is a very simple view presenting the number of elements in a stream or view. The view computes a single long-typed count of the number of events passed through it similar to the base statistics COUNT column.


Field Summary
protected  java.lang.Object[] lastValuesEventNew
           
protected  long size
           
 
Fields inherited from class com.espertech.esper.view.ViewSupport
EMPTY_VIEW_ARRAY, parent
 
Constructor Summary
SizeView(AgentInstanceContext agentInstanceContext, EventType eventType, StatViewAdditionalProps additionalProps)
          Ctor.
 
Method Summary
 View cloneView()
          Duplicates the view.
static EventType createEventType(StatementContext statementContext, StatViewAdditionalProps additionalProps, int streamNum)
          Creates the event type for this view
 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.
 java.lang.String toString()
           
 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, addView, dumpChildViews, dumpUpdateParams, dumpUpdateParams, findDescendent, findViewIndex, getParent, getViews, hasViews, removeAllViews, removeView, removeView, setParent, updateChildren, updateChildren
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

size

protected long size

lastValuesEventNew

protected java.lang.Object[] lastValuesEventNew
Constructor Detail

SizeView

public SizeView(AgentInstanceContext agentInstanceContext,
                EventType eventType,
                StatViewAdditionalProps additionalProps)
Ctor.

Parameters:
agentInstanceContext - is services
Method Detail

cloneView

public View cloneView()
Description copied from interface: CloneableView
Duplicates the view.

Expected to return a same view in initialized state for grouping.

Specified by:
cloneView in interface CloneableView

getEventType

public final 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

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

iterator

public final 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.

toString

public final java.lang.String toString()
Overrides:
toString in class java.lang.Object

createEventType

public static EventType createEventType(StatementContext statementContext,
                                        StatViewAdditionalProps additionalProps,
                                        int streamNum)
Creates the event type for this view

Parameters:
statementContext - is the event adapter service
Returns:
event type for view

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