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.common.worker;
  
  import java.io.Closeable;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.annotations.VisibleForTesting;
  
  /** A flatten operation. */
  public class FlattenOperation extends ReceivingOperation {
    public FlattenOperation(OutputReceiver[] receivers, OperationContext context) {
      super(receivers, context);
    }
  
    /** Invoked by tests. */
    @VisibleForTesting
    public FlattenOperation(OutputReceiver outputReceiver, OperationContext context) {
      this(new OutputReceiver[] {outputReceiver}, context);
    }
  
    @Override
    public void process(Object elem) throws Exception {
      try (Closeable scope = context.enterProcess()) {
        checkStarted();
        Receiver receiver = receivers[0];
        if (receiver != null) {
          receiver.process(elem);
        }
      }
    }
  
    @Override
    public boolean supportsRestart() {
      return true;
    }
  }
  