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;
  
  import com.google.auto.service.AutoService;
  import java.io.Closeable;
  import java.io.IOException;
  import org.apache.beam.runners.core.metrics.ExecutionStateTracker;
  import org.apache.beam.sdk.metrics.MetricsEnvironment;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.annotations.VisibleForTesting;
  
  /**
   * Registration of a {@link ContextActivationObserver} for the {@link MetricsEnvironment} with the
   * {@link DataflowExecutionContext}.
   */
  public class MetricsEnvironmentContextActivationObserverRegistration {
  
    /** A {@link ContextActivationObserver} to register default metrics. */
    @VisibleForTesting
    static class MetricsEnvironmentContextActivationObserver implements ContextActivationObserver {
      @Override
      public void close() throws IOException {}
  
      @Override
      public Closeable activate(ExecutionStateTracker e) {
        return MetricsEnvironment.scopedMetricsContainer(new DataflowMetricsContainer(e));
      }
    }
  
    /**
     * A {@link ContextActivationObserver.Registrar} to register {@link ContextActivationObserver} for
     * {@link MetricsEnvironment}.
     */
    @AutoService(ContextActivationObserver.Registrar.class)
    public static class MetricsEnvironmentContextActivationObserverRegistrar
        implements ContextActivationObserver.Registrar {
  
      @Override
      public boolean isEnabled() {
        return true;
      }
  
      @Override
      public ContextActivationObserver getContextActivationObserver() {
        return new MetricsEnvironmentContextActivationObserver();
      }
    }
  }
  