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

Class CountSlidingWindowAssigner

java.lang.Object

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

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

All Implemented Interfaces:

Serializable

public class CountSlidingWindowAssigner
extends WindowAssigner<CountWindow>

A WindowAssigner that windows elements into sliding windows based on the count number of the elements. Windows can possibly overlap.

See Also:

Serialized Form

Method Summary

Modifier and Type	Method and Description
Collection<CountWindow>	assignWindows(RowData element, long timestamp) Given the timestamp and element, returns the set of windows into which it should be placed.
TypeSerializer<CountWindow>	getWindowSerializer(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.
static CountSlidingWindowAssigner	of(long windowSize, long windowSlide)
void	open(InternalWindowProcessFunction.Context<?,CountWindow> ctx) Initialization method for the function.
String	toString()

Methods inherited from class java.lang.Object

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

Method Detail

open

public void open(InternalWindowProcessFunction.Context<?,CountWindow> ctx)
          throws Exception

Description copied from class: WindowAssigner

Initialization method for the function. It is called before the actual working methods.

Overrides:

open in class WindowAssigner<CountWindow>

Throws:

Exception

assignWindows

public Collection<CountWindow> assignWindows(RowData element,
                                             long timestamp)
                                      throws IOException

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<CountWindow>

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. The timestamp value is mapping to UTC milliseconds for splitting windows simply.

Throws:

IOException

getWindowSerializer

public TypeSerializer<CountWindow> getWindowSerializer(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<CountWindow>

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<CountWindow>

toString

public String toString()

Specified by:

toString in class WindowAssigner<CountWindow>

of

public static CountSlidingWindowAssigner of(long windowSize,
                                            long windowSlide)