com.google.cloud.dataflow.sdk.util

Class MergingActiveWindowSet<W extends BoundedWindow>

java.lang.Object

com.google.cloud.dataflow.sdk.util.MergingActiveWindowSet<W>

Type Parameters:

W - the types of windows being managed

All Implemented Interfaces:

ActiveWindowSet<W>

public class MergingActiveWindowSet<W extends BoundedWindow>
extends Object
implements ActiveWindowSet<W>

Implementation of ActiveWindowSet used with WindowFns that support merging.

Nested Class Summary

Nested classes/interfaces inherited from interface com.google.cloud.dataflow.sdk.util.ActiveWindowSet

ActiveWindowSet.MergeCallback<W extends BoundedWindow>

Constructor Summary

Constructors

Constructor and Description
MergingActiveWindowSet(WindowFn<Object,W> windowFn, StateInternals state)

Method Summary

Modifier and Type	Method and Description
boolean	add(W window) Add a window to the ActiveWindowSet.
boolean	mergeIfAppropriate(W window, ActiveWindowSet.MergeCallback<W> mergeCallback) Invoke merge on the associated WindowFn, and return true if the window still exists afterwards.
void	persist() Save any state changes needed.
void	remove(W window) Remove a window from the ActiveWindowSet.
Iterable<W>	sourceWindows(W window) Return the set of windows that were merged to produce window.

Methods inherited from class java.lang.Object

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

Constructor Detail

MergingActiveWindowSet

public MergingActiveWindowSet(WindowFn<Object,W> windowFn,
                              StateInternals state)

Method Detail

persist

public void persist()

Description copied from interface: ActiveWindowSet

Save any state changes needed.

Specified by:

persist in interface ActiveWindowSet<W extends BoundedWindow>

add

public boolean add(W window)

Description copied from interface: ActiveWindowSet

Add a window to the ActiveWindowSet.

Specified by:

add in interface ActiveWindowSet<W extends BoundedWindow>

Returns:

false if the window was definitely not-active before being added, true if it either was already active, or the implementation doesn't have enough information to know.

remove

public void remove(W window)

Description copied from interface: ActiveWindowSet

Remove a window from the ActiveWindowSet.

Specified by:

remove in interface ActiveWindowSet<W extends BoundedWindow>

mergeIfAppropriate

public boolean mergeIfAppropriate(W window,
                                  ActiveWindowSet.MergeCallback<W> mergeCallback)
                           throws Exception

Description copied from interface: ActiveWindowSet

Invoke merge on the associated WindowFn, and return true if the window still exists afterwards.

Specified by:

mergeIfAppropriate in interface ActiveWindowSet<W extends BoundedWindow>

Throws:

Exception

sourceWindows

public Iterable<W> sourceWindows(W window)

Description copied from interface: ActiveWindowSet

Return the set of windows that were merged to produce window. If the associated WindowFn never merges windows, then this should return the singleton list containing window.

Specified by:

sourceWindows in interface ActiveWindowSet<W extends BoundedWindow>