| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.beam.sdk.values; |
| |
| import java.io.Serializable; |
| import javax.annotation.Nullable; |
| import org.apache.beam.sdk.PipelineRunner; |
| import org.apache.beam.sdk.annotations.Experimental; |
| import org.apache.beam.sdk.annotations.Experimental.Kind; |
| import org.apache.beam.sdk.annotations.Internal; |
| import org.apache.beam.sdk.coders.Coder; |
| import org.apache.beam.sdk.transforms.ParDo; |
| import org.apache.beam.sdk.transforms.View; |
| import org.apache.beam.sdk.transforms.ViewFn; |
| import org.apache.beam.sdk.transforms.windowing.WindowMappingFn; |
| |
| /** |
| * A {@link PCollectionView PCollectionView<T>} is an immutable view of a {@link PCollection} |
| * as a value of type {@code T} that can be accessed as a side input to a {@link ParDo} transform. |
| * |
| * <p>A {@link PCollectionView} should always be the output of a {@link |
| * org.apache.beam.sdk.transforms.PTransform}. It is the joint responsibility of this transform and |
| * each {@link PipelineRunner} to implement the view in a runner-specific manner. |
| * |
| * <p>The most common case is using the {@link View} transforms to prepare a {@link PCollection} for |
| * use as a side input to {@link ParDo}. See {@link View#asSingleton()}, {@link View#asIterable()}, |
| * and {@link View#asMap()} for more detail on specific views available in the SDK. |
| * |
| * <p>NOTE: View methods should not be considered to be user-accessible. They are implementation |
| * details of how a Runner obtains information required to construct a view, and are subject to |
| * change at any time. |
| * |
| * @param <T> the type of the value(s) accessible via this {@link PCollectionView} |
| */ |
| public interface PCollectionView<T> extends PValue, Serializable { |
| /** |
| * <b>For internal use only.</b> |
| * |
| * <p>Gets the {@link PCollection} this {@link PCollectionView} was created from. |
| * |
| * <p>The {@link PCollection} may not be available in all contexts. |
| */ |
| @Nullable |
| @Internal |
| PCollection<?> getPCollection(); |
| /** |
| * <b>For internal use only.</b> |
| * |
| * @deprecated this method will be removed entirely. The {@link PCollection} underlying a side |
| * input, is part of the side input's specification with a {@link ParDo} transform, which will |
| * obtain that information via a package-private channel. |
| */ |
| @Deprecated |
| @Internal |
| TupleTag<?> getTagInternal(); |
| |
| /** |
| * <b>For internal use only.</b> |
| * |
| * @deprecated this method will be removed entirely. The {@link ViewFn} for a side input is an |
| * attribute of the side input's specification with a {@link ParDo} transform, which will |
| * obtain this specification via a package-private channel. |
| */ |
| @Deprecated |
| @Internal |
| ViewFn<?, T> getViewFn(); |
| |
| /** |
| * <b>For internal use only.</b> |
| * |
| * <p>Returns the {@link WindowMappingFn} used to map windows from a main input to the side input |
| * of this {@link PCollectionView}. |
| */ |
| @Experimental(Kind.CORE_RUNNERS_ONLY) |
| @Internal |
| WindowMappingFn<?> getWindowMappingFn(); |
| |
| /** |
| * <b>For internal use only.</b> |
| * |
| * @deprecated this method will be removed entirely. The {@link PCollection} underlying a side |
| * input, including its {@link WindowingStrategy}, is part of the side input's specification |
| * with a {@link ParDo} transform, which will obtain that information via a package-private |
| * channel. |
| */ |
| @Deprecated |
| @Internal |
| WindowingStrategy<?, ?> getWindowingStrategyInternal(); |
| |
| /** |
| * <b>For internal use only.</b> |
| * |
| * @deprecated this method will be removed entirely. The {@link PCollection} underlying a side |
| * input, including its {@link Coder}, is part of the side input's specification with a {@link |
| * ParDo} transform, which will obtain that information via a package-private channel. |
| */ |
| @Deprecated |
| @Internal |
| Coder<?> getCoderInternal(); |
| } |