Package org.apache.beam.sdk.transforms.windowing

Class FixedWindows

java.lang.Object

org.apache.beam.sdk.transforms.windowing.WindowFn<Object,IntervalWindow>

org.apache.beam.sdk.transforms.windowing.NonMergingWindowFn<Object,IntervalWindow>

org.apache.beam.sdk.transforms.windowing.PartitioningWindowFn<Object,IntervalWindow>

org.apache.beam.sdk.transforms.windowing.FixedWindows

All Implemented Interfaces:

Serializable, HasDisplayData

public class FixedWindows
extends PartitioningWindowFn<Object,IntervalWindow>

A WindowFn that windows values into fixed-size timestamp-based windows.

For example, in order to partition the data into 10 minute windows:

 PCollection<Integer> items = ...;
 PCollection<Integer> windowedItems = items.apply(
   Window.<Integer>into(FixedWindows.of(Duration.standardMinutes(10))));
 

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.beam.sdk.transforms.windowing.WindowFn

WindowFn.AssignContext, WindowFn.MergeContext

Method Summary

Modifier and Type	Method	Description
IntervalWindow	assignWindow(Instant timestamp)	Returns the single window to which elements with this timestamp belong.
boolean	equals(@Nullable Object object)
Duration	getOffset()
Duration	getSize()
int	hashCode()
boolean	isCompatible(WindowFn<?,?> other)	Returns whether this performs the same merging as the given WindowFn.
static FixedWindows	of(Duration size)	Partitions the timestamp space into half-open intervals of the form [N * size, (N + 1) * size), where 0 is the epoch.
void	populateDisplayData(DisplayData.Builder builder)	Register display data for the given transform or component.
void	verifyCompatibility(WindowFn<?,?> other)	Throw IncompatibleWindowException if this WindowFn does not perform the same merging as the given $WindowFn.
Coder<IntervalWindow>	windowCoder()	Returns the Coder used for serializing the windows used by this windowFn.
FixedWindows	withOffset(Duration offset)	Partitions the timestamp space into half-open intervals of the form [N * size + offset, (N + 1) * size + offset), where 0 is the epoch.

Methods inherited from class org.apache.beam.sdk.transforms.windowing.PartitioningWindowFn

assignsToOneWindow, assignWindows, getDefaultWindowMappingFn

Methods inherited from class org.apache.beam.sdk.transforms.windowing.NonMergingWindowFn

isNonMerging, mergeWindows

Methods inherited from class org.apache.beam.sdk.transforms.windowing.WindowFn

getWindowTypeDescriptor

Methods inherited from class java.lang.Object

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

Method Details

of

public static FixedWindows of(Duration size)

Partitions the timestamp space into half-open intervals of the form [N * size, (N + 1) * size), where 0 is the epoch.

withOffset

public FixedWindows withOffset(Duration offset)

Partitions the timestamp space into half-open intervals of the form [N * size + offset, (N + 1) * size + offset), where 0 is the epoch.

Throws:

IllegalArgumentException - if offset is not in [0, size)

assignWindow

public IntervalWindow assignWindow(Instant timestamp)

Description copied from class: PartitioningWindowFn

Returns the single window to which elements with this timestamp belong.

Specified by:

assignWindow in class PartitioningWindowFn<Object,IntervalWindow>

populateDisplayData

public void populateDisplayData(DisplayData.Builder builder)

Description copied from class: WindowFn

Register display data for the given transform or component.

populateDisplayData(DisplayData.Builder) is invoked by Pipeline runners to collect display data via DisplayData.from(HasDisplayData). Implementations may call super.populateDisplayData(builder) in order to register display data in the current namespace, but should otherwise use subcomponent.populateDisplayData(builder) to use the namespace of the subcomponent.

By default, does not register any display data. Implementors may override this method to provide their own display data.

Specified by:

populateDisplayData in interface HasDisplayData

Overrides:

populateDisplayData in class WindowFn<Object,IntervalWindow>

Parameters:

builder - The builder to populate with display data.

See Also:

• HasDisplayData

windowCoder

public Coder<IntervalWindow> windowCoder()

Description copied from class: WindowFn

Returns the Coder used for serializing the windows used by this windowFn.

Specified by:

windowCoder in class WindowFn<Object,IntervalWindow>

isCompatible

public boolean isCompatible(WindowFn<?,?> other)

Description copied from class: WindowFn

Returns whether this performs the same merging as the given WindowFn.

Specified by:

isCompatible in class WindowFn<Object,IntervalWindow>

verifyCompatibility

public void verifyCompatibility(WindowFn<?,?> other)
                         throws IncompatibleWindowException

Description copied from class: WindowFn

Throw IncompatibleWindowException if this WindowFn does not perform the same merging as the given $WindowFn.

Overrides:

verifyCompatibility in class WindowFn<Object,IntervalWindow>

Throws:

IncompatibleWindowException - if compared WindowFns are not compatible.

getSize

public Duration getSize()

getOffset

public Duration getOffset()

equals

public boolean equals(@Nullable Object object)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object