com.ibm.streams.operator.window

Class StreamWindowEvent<T>

java.lang.Object

java.util.EventObject

com.ibm.streams.operator.window.StreamWindowEvent<T>

Type Parameters:

T - Tuple type.

All Implemented Interfaces:

java.io.Serializable

public class StreamWindowEvent<T>
extends java.util.EventObject

An event for a windowed input port.
The source of the event (getSource()) is the StreamWindow for the window.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	StreamWindowEvent.Type Stream window event type.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	IBM_COPYRIGHT

Fields inherited from class java.util.EventObject

source

Constructor Summary

Constructors

Constructor and Description
StreamWindowEvent(StreamWindowEvent.Type type, StreamWindow<T> window, java.lang.Object partition, java.lang.Iterable<T> tuples)

Method Summary

Methods

Modifier and Type	Method and Description
java.lang.Object	getPartition() The partition the event is for.
java.lang.Iterable<T>	getTuples() A sequence of tuples in arrival order, from oldest to most recent.
StreamWindowEvent.Type	getType() The type of the event.

Methods inherited from class java.util.EventObject

getSource, toString

Methods inherited from class java.lang.Object

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

Field Detail

IBM_COPYRIGHT

public static final java.lang.String IBM_COPYRIGHT

See Also:

Constant Field Values

Constructor Detail

StreamWindowEvent

public StreamWindowEvent(StreamWindowEvent.Type type,
                 StreamWindow<T> window,
                 java.lang.Object partition,
                 java.lang.Iterable<T> tuples)

Method Detail

getPartition

public final java.lang.Object getPartition()

The partition the event is for. When a window is partitioned the returned value will be the result of executing the registered StreamWindowPartitioner against a tuple.
When a window is not partitioned all events will return a java.lang.Integer with value zero.

Returns:

the partition

getType

public final StreamWindowEvent.Type getType()

The type of the event.

Returns:

Type of this event

getTuples

public final java.lang.Iterable<T> getTuples()

A sequence of tuples in arrival order, from oldest to most recent.

For an INSERTION event the sequence represents the tuples being inserted into a window. Multiple tuple arrivals may be batched into a single INSERTION event, thus a listener should never assume the event only contains a single tuple.
For an EVICTION event the sequence represents the sub-set of tuples being evicted from a window that have a reference to their tuple instance. Multiple tuple evictions may be batched into a single EVICITON event, thus a listener should never assume the event only contains a single tuple.
For all other event types the collection represents sub-set of logical tuples currently in the window that have a reference to their tuple instance.

Executing Iterator.remove() for a tuple will result in the tuple reference being removed from the window to allow garbage collection of the tuple object (by not having the StreamWindow implementation hold its reference). The tuple logically remains in the window but its attribute values are no longer available through instances of StreamWindowEvent.