com.google.cloud.dataflow.sdk.transforms.windowing

Class SlidingWindows

java.lang.Object

com.google.cloud.dataflow.sdk.transforms.windowing.WindowingFn<T,W>

com.google.cloud.dataflow.sdk.transforms.windowing.NonMergingWindowingFn<java.lang.Object,IntervalWindow>

com.google.cloud.dataflow.sdk.transforms.windowing.SlidingWindows

All Implemented Interfaces:

java.io.Serializable

public class SlidingWindows
extends NonMergingWindowingFn<java.lang.Object,IntervalWindow>

A WindowingFn that windows values into possibly overlapping fixed-size timestamp-based windows.

For example, in order to window data into 10 minute windows that update every minute:

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

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.google.cloud.dataflow.sdk.transforms.windowing.WindowingFn

WindowingFn.AssignContext, WindowingFn.MergeContext

Method Summary

Methods

Modifier and Type	Method and Description
java.util.Collection<IntervalWindow>	assignWindows(WindowingFn.AssignContext c) Given a timestamp and element, returns the set of windows into which it should be placed.
SlidingWindows	every(Duration period) Returns a new SlidingWindows with the original size, that assigns timestamps into half-open intervals of the form [N * period, N * period + size), where 0 is the epoch.
boolean	isCompatible(WindowingFn<?,?> other) Returns whether this performs the same merging as the given WindowingFn.
static SlidingWindows	of(Duration size) Assigns timestamps into half-open intervals of the form [N * period, N * period + size), where 0 is the epoch.
Coder<IntervalWindow>	windowCoder() Returns the Coder used for serializing the windows used by this windowingFn.
SlidingWindows	withOffset(Duration offset) Assigns timestamps into half-open intervals of the form [N * period + offset, N * period + offset + size).

Methods inherited from class com.google.cloud.dataflow.sdk.transforms.windowing.NonMergingWindowingFn

mergeWindows

Methods inherited from class java.lang.Object

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

Method Detail

of

public static SlidingWindows of(Duration size)

Assigns timestamps into half-open intervals of the form [N * period, N * period + size), where 0 is the epoch.

If every(org.joda.time.Duration) is not called, the period defaults to one millisecond.

every

public SlidingWindows every(Duration period)

Returns a new SlidingWindows with the original size, that assigns timestamps into half-open intervals of the form [N * period, N * period + size), where 0 is the epoch.

withOffset

public SlidingWindows withOffset(Duration offset)

Assigns timestamps into half-open intervals of the form [N * period + offset, N * period + offset + size).

Throws:

java.lang.IllegalArgumentException - if offset is not in [0, period)

windowCoder

public Coder<IntervalWindow> windowCoder()

Description copied from class: WindowingFn

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

Specified by:

windowCoder in class WindowingFn<java.lang.Object,IntervalWindow>

assignWindows

public java.util.Collection<IntervalWindow> assignWindows(WindowingFn.AssignContext c)

Description copied from class: WindowingFn

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

Specified by:

assignWindows in class WindowingFn<java.lang.Object,IntervalWindow>

isCompatible

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

Description copied from class: WindowingFn

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

Specified by:

isCompatible in class WindowingFn<java.lang.Object,IntervalWindow>