org.apache.beam.sdk.values

Class PCollectionViews

java.lang.Object

org.apache.beam.sdk.values.PCollectionViews

@Internal
public class PCollectionViews
extends java.lang.Object

For internal use only; no backwards compatibility guarantees.

Implementations of PCollectionView shared across the SDK.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	PCollectionViews.IterableViewFn<T> Implementation which is able to adapt a multimap materialization to a Iterable<T>.
static class	PCollectionViews.ListViewFn<T> Implementation which is able to adapt a multimap materialization to a List<T>.
static class	PCollectionViews.MapViewFn<K,V> Implementation which is able to adapt a multimap materialization to a Map<K, V>.
static class	PCollectionViews.MultimapViewFn<K,V> Implementation which is able to adapt a multimap materialization to a Map<K, Iterable<V>>.
static class	PCollectionViews.SimplePCollectionView<ElemT,PrimitiveViewT,ViewT,W extends BoundedWindow> A class for PCollectionView implementations, with additional type parameters that are not visible at pipeline assembly time when the view is used as a side input.
static class	PCollectionViews.SingletonViewFn<T> Implementation which is able to adapt a multimap materialization to a T.

Constructor Summary

Constructors

Constructor and Description
PCollectionViews()

Method Summary

Modifier and Type	Method and Description
static <T,W extends BoundedWindow> PCollectionView<java.lang.Iterable<T>>	iterableView(PCollection<KV<java.lang.Void,T>> pCollection, WindowingStrategy<?,W> windowingStrategy) Returns a PCollectionView<Iterable<T>> capable of processing elements windowed using the provided WindowingStrategy.
static <T,W extends BoundedWindow> PCollectionView<java.util.List<T>>	listView(PCollection<KV<java.lang.Void,T>> pCollection, WindowingStrategy<?,W> windowingStrategy) Returns a PCollectionView<List<T>> capable of processing elements windowed using the provided WindowingStrategy.
static <K,V,W extends BoundedWindow> PCollectionView<java.util.Map<K,V>>	mapView(PCollection<KV<java.lang.Void,KV<K,V>>> pCollection, WindowingStrategy<?,W> windowingStrategy) Returns a PCollectionView<Map<K, V>> capable of processing elements windowed using the provided WindowingStrategy.
static <K,V,W extends BoundedWindow> PCollectionView<java.util.Map<K,java.lang.Iterable<V>>>	multimapView(PCollection<KV<java.lang.Void,KV<K,V>>> pCollection, WindowingStrategy<?,W> windowingStrategy) Returns a PCollectionView<Map<K, Iterable<V>>> capable of processing elements windowed using the provided WindowingStrategy.
static <T,W extends BoundedWindow> PCollectionView<T>	singletonView(PCollection<KV<java.lang.Void,T>> pCollection, WindowingStrategy<?,W> windowingStrategy, boolean hasDefault, T defaultValue, Coder<T> defaultValueCoder) Returns a PCollectionView<T> capable of processing elements windowed using the provided WindowingStrategy.
static java.util.Map<TupleTag<?>,PValue>	toAdditionalInputs(java.lang.Iterable<PCollectionView<?>> views) Expands a list of PCollectionView into the form needed for PTransform.getAdditionalInputs().

Methods inherited from class java.lang.Object

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

Constructor Detail

PCollectionViews

public PCollectionViews()

Method Detail

singletonView

public static <T,W extends BoundedWindow> PCollectionView<T> singletonView(PCollection<KV<java.lang.Void,T>> pCollection,
                                                                           WindowingStrategy<?,W> windowingStrategy,
                                                                           boolean hasDefault,
                                                                           @Nullable
                                                                           T defaultValue,
                                                                           Coder<T> defaultValueCoder)

Returns a PCollectionView<T> capable of processing elements windowed using the provided WindowingStrategy.

If hasDefault is true, then the view will take on the value defaultValue for any empty windows.

iterableView

public static <T,W extends BoundedWindow> PCollectionView<java.lang.Iterable<T>> iterableView(PCollection<KV<java.lang.Void,T>> pCollection,
                                                                                              WindowingStrategy<?,W> windowingStrategy)

Returns a PCollectionView<Iterable<T>> capable of processing elements windowed using the provided WindowingStrategy.

listView

public static <T,W extends BoundedWindow> PCollectionView<java.util.List<T>> listView(PCollection<KV<java.lang.Void,T>> pCollection,
                                                                                      WindowingStrategy<?,W> windowingStrategy)

Returns a PCollectionView<List<T>> capable of processing elements windowed using the provided WindowingStrategy.

mapView

public static <K,V,W extends BoundedWindow> PCollectionView<java.util.Map<K,V>> mapView(PCollection<KV<java.lang.Void,KV<K,V>>> pCollection,
                                                                                        WindowingStrategy<?,W> windowingStrategy)

Returns a PCollectionView<Map<K, V>> capable of processing elements windowed using the provided WindowingStrategy.

multimapView

public static <K,V,W extends BoundedWindow> PCollectionView<java.util.Map<K,java.lang.Iterable<V>>> multimapView(PCollection<KV<java.lang.Void,KV<K,V>>> pCollection,
                                                                                                                 WindowingStrategy<?,W> windowingStrategy)

Returns a PCollectionView<Map<K, Iterable<V>>> capable of processing elements windowed using the provided WindowingStrategy.

toAdditionalInputs

public static java.util.Map<TupleTag<?>,PValue> toAdditionalInputs(java.lang.Iterable<PCollectionView<?>> views)

Expands a list of PCollectionView into the form needed for PTransform.getAdditionalInputs().