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.List;
  import java.util.Map;
  import org.apache.beam.sdk.util.WindowedValueMultiReceiver;
  import org.apache.beam.sdk.values.TupleTag;
  import org.apache.beam.sdk.values.WindowedValue;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Lists;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Maps;
  
  /**
   * An implementation of {@code OutputManager} using simple lists, for testing and in-memory contexts
   * such as the {@code DirectRunner}.
   */
  public class ListOutputManager implements WindowedValueMultiReceiver {
  
    private Map<TupleTag<?>, List<WindowedValue<?>>> outputLists = Maps.newHashMap();
  
    public <T> List<WindowedValue<T>> getOutput(TupleTag<T> tag) {
      List<WindowedValue<T>> outputList = (List<WindowedValue<T>>) (Object) outputLists.get(tag);
      if (outputList != null) {
        return outputList;
      } else {
        outputList = Lists.newArrayList();
        outputLists.put(tag, (List<WindowedValue<?>>) (Object) outputList);
        return outputList;
      }
    }
  
    @Override
    public <OutputT> void output(TupleTag<OutputT> tag, WindowedValue<OutputT> output) {
      List<WindowedValue<OutputT>> outputList = getOutput(tag);
      outputList.add(output);
    }
  }
  