content: /*
   * 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.runners.dataflow;
  
  import org.apache.beam.sdk.transforms.PTransform;
  import org.apache.beam.sdk.values.PCollection;
  import org.apache.beam.sdk.values.PCollectionView;
  
  /** A {@link DataflowRunner} marker class for creating a {@link PCollectionView}. */
  @SuppressWarnings({
    "nullness" // TODO(https://github.com/apache/beam/issues/20497)
  })
  public class CreateDataflowView<ElemT, ViewT>
      extends PTransform<PCollection<ElemT>, PCollection<ElemT>> {
    public static <ElemT, ViewT> CreateDataflowView<ElemT, ViewT> forBatch(
        PCollectionView<ViewT> view) {
      return new CreateDataflowView<>(view, false);
    }
  
    public static <ElemT, ViewT> CreateDataflowView<ElemT, ViewT> forStreaming(
        PCollectionView<ViewT> view) {
      return new CreateDataflowView<>(view, true);
    }
  
    private final PCollectionView<ViewT> view;
    private final boolean streaming;
  
    private CreateDataflowView(PCollectionView<ViewT> view, boolean streaming) {
      this.view = view;
      this.streaming = streaming;
    }
  
    @Override
    public PCollection<ElemT> expand(PCollection<ElemT> input) {
      if (streaming) {
        return PCollection.createPrimitiveOutputInternal(
            input.getPipeline(), input.getWindowingStrategy(), input.isBounded(), input.getCoder());
      }
      return (PCollection) view.getPCollection();
    }
  
    public PCollectionView<ViewT> getView() {
      return view;
    }
  }
  