org.apache.flink.table.runtime.operators.window.assigners

Class SessionWindowAssigner

java.lang.Object

org.apache.flink.table.runtime.operators.window.assigners.WindowAssigner<W>

org.apache.flink.table.runtime.operators.window.assigners.MergingWindowAssigner<TimeWindow>

org.apache.flink.table.runtime.operators.window.assigners.SessionWindowAssigner

All Implemented Interfaces:

Serializable, InternalTimeWindowAssigner

public class SessionWindowAssigner
extends MergingWindowAssigner<TimeWindow>
implements InternalTimeWindowAssigner

A WindowAssigner that windows elements into sessions based on the timestamp. Windows cannot overlap.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.flink.table.runtime.operators.window.assigners.MergingWindowAssigner

MergingWindowAssigner.MergeCallback<W>

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SessionWindowAssigner(long sessionGap, boolean isEventTime)

Method Summary

Modifier and Type	Method and Description
Collection<TimeWindow>	assignWindows(BaseRow element, long timestamp) Given the timestamp and element, returns the set of windows into which it should be placed.
org.apache.flink.api.common.typeutils.TypeSerializer<TimeWindow>	getWindowSerializer(org.apache.flink.api.common.ExecutionConfig executionConfig) Returns a TypeSerializer for serializing windows that are assigned by this WindowAssigner.
boolean	isEventTime() Returns true if elements are assigned to windows based on event time, false otherwise.
void	mergeWindows(TimeWindow newWindow, NavigableSet<TimeWindow> sortedWindows, MergingWindowAssigner.MergeCallback<TimeWindow> callback) Determines which windows (if any) should be merged.
String	toString()
SessionWindowAssigner	withEventTime()
static SessionWindowAssigner	withGap(java.time.Duration size) Creates a new SessionWindowAssigner WindowAssigner that assigns elements to sessions based on the timestamp.
SessionWindowAssigner	withProcessingTime()

Methods inherited from class org.apache.flink.table.runtime.operators.window.assigners.WindowAssigner

open

Methods inherited from class java.lang.Object

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

Constructor Detail

SessionWindowAssigner

protected SessionWindowAssigner(long sessionGap,
                                boolean isEventTime)

Method Detail

assignWindows

public Collection<TimeWindow> assignWindows(BaseRow element,
                                            long timestamp)

Description copied from class: WindowAssigner

Given the timestamp and element, returns the set of windows into which it should be placed.

Specified by:

assignWindows in class WindowAssigner<TimeWindow>

Parameters:

element - The element to which windows should be assigned.

timestamp - The timestamp of the element when WindowAssigner.isEventTime() returns true, or the current system time when WindowAssigner.isEventTime() returns false.

mergeWindows

public void mergeWindows(TimeWindow newWindow,
                         NavigableSet<TimeWindow> sortedWindows,
                         MergingWindowAssigner.MergeCallback<TimeWindow> callback)

Description copied from class: MergingWindowAssigner

Determines which windows (if any) should be merged.

Specified by:

mergeWindows in class MergingWindowAssigner<TimeWindow>

Parameters:

newWindow - The new window

sortedWindows - The sorted window candidates.

callback - A callback that can be invoked to signal which windows should be merged.

getWindowSerializer

public org.apache.flink.api.common.typeutils.TypeSerializer<TimeWindow> getWindowSerializer(org.apache.flink.api.common.ExecutionConfig executionConfig)

Description copied from class: WindowAssigner

Returns a TypeSerializer for serializing windows that are assigned by this WindowAssigner.

Specified by:

getWindowSerializer in class WindowAssigner<TimeWindow>

isEventTime

public boolean isEventTime()

Description copied from class: WindowAssigner

Returns true if elements are assigned to windows based on event time, false otherwise.

Specified by:

isEventTime in class WindowAssigner<TimeWindow>

toString

public String toString()

Specified by:

toString in class WindowAssigner<TimeWindow>

withGap

public static SessionWindowAssigner withGap(java.time.Duration size)

Creates a new SessionWindowAssigner WindowAssigner that assigns elements to sessions based on the timestamp.

Parameters:

size - The session timeout, i.e. the time gap between sessions

Returns:

The policy.

withEventTime

public SessionWindowAssigner withEventTime()

Specified by:

withEventTime in interface InternalTimeWindowAssigner

Returns:

an InternalTimeWindowAssigner which in event time mode.

withProcessingTime

public SessionWindowAssigner withProcessingTime()

Specified by:

withProcessingTime in interface InternalTimeWindowAssigner

Returns:

an InternalTimeWindowAssigner which in processing time mode.