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.direct;
  
  import org.apache.beam.sdk.runners.AppliedPTransform;
  import org.apache.beam.sdk.runners.PTransformOverrideFactory;
  import org.apache.beam.sdk.transforms.GroupByKey;
  import org.apache.beam.sdk.transforms.PTransform;
  import org.apache.beam.sdk.util.construction.PTransformReplacements;
  import org.apache.beam.sdk.util.construction.SingleInputOutputOverrideFactory;
  import org.apache.beam.sdk.values.KV;
  import org.apache.beam.sdk.values.PCollection;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Iterables;
  
  /** A {@link PTransformOverrideFactory} for {@link GroupByKey} PTransforms. */
  final class DirectGroupByKeyOverrideFactory<K, V>
      extends SingleInputOutputOverrideFactory<
          PCollection<KV<K, V>>,
          PCollection<KV<K, Iterable<V>>>,
          PTransform<PCollection<KV<K, V>>, PCollection<KV<K, Iterable<V>>>>> {
    @Override
    public PTransformReplacement<PCollection<KV<K, V>>, PCollection<KV<K, Iterable<V>>>>
        getReplacementTransform(
            AppliedPTransform<
                    PCollection<KV<K, V>>,
                    PCollection<KV<K, Iterable<V>>>,
                    PTransform<PCollection<KV<K, V>>, PCollection<KV<K, Iterable<V>>>>>
                transform) {
  
      PCollection<KV<K, Iterable<V>>> output =
          (PCollection<KV<K, Iterable<V>>>) Iterables.getOnlyElement(transform.getOutputs().values());
  
      return PTransformReplacement.of(
          PTransformReplacements.getSingletonMainInput(transform),
          new DirectGroupByKey<>(transform.getTransform(), output.getWindowingStrategy()));
    }
  }
  