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.worker.util;
  
  import java.util.Collections;
  import org.apache.beam.runners.core.SideInputReader;
  import org.apache.beam.runners.core.StepContext;
  import org.apache.beam.sdk.options.PipelineOptions;
  import org.apache.beam.sdk.transforms.windowing.BoundedWindow;
  import org.apache.beam.sdk.transforms.windowing.ReshuffleTrigger;
  import org.apache.beam.sdk.util.WindowedValueReceiver;
  import org.apache.beam.sdk.values.KV;
  import org.apache.beam.sdk.values.WindowedValue;
  import org.apache.beam.sdk.values.WindowingStrategy;
  
  /**
   * Implementation of {@link BatchGroupAlsoByWindowFn} used for the {@link ReshuffleTrigger} which
   * outputs each element as a separate pane.
   *
   * @param <K> key type
   * @param <V> value element type
   * @param <W> window type
   */
  public class BatchGroupAlsoByWindowReshuffleFn<K, V, W extends BoundedWindow>
      extends BatchGroupAlsoByWindowFn<K, V, Iterable<V>> {
  
    public static boolean isReshuffle(WindowingStrategy<?, ?> strategy) {
      return strategy.getTrigger() instanceof ReshuffleTrigger;
    }
  
    @Override
    public void processElement(
        KV<K, Iterable<WindowedValue<V>>> element,
        PipelineOptions options,
        StepContext stepContext,
        SideInputReader sideInputReader,
        WindowedValueReceiver<KV<K, Iterable<V>>> output)
        throws Exception {
      K key = element.getKey();
      for (WindowedValue<V> item : element.getValue()) {
        output.output(item.withValue(KV.of(key, Collections.singletonList(item.getValue()))));
      }
    }
  }
  