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.sdk.extensions.euphoria.core.client.accumulators;
  
  import java.time.Duration;
  import java.util.concurrent.atomic.AtomicBoolean;
  import org.apache.beam.sdk.extensions.euphoria.core.annotation.audience.Audience;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Placeholder implementation of {@link AccumulatorProvider} that may be used in executors as a
   * default.
   *
   * @deprecated Use Java SDK directly, Euphoria is scheduled for removal in a future release.
   */
  @Audience(Audience.Type.EXECUTOR)
  @Deprecated
  public class VoidAccumulatorProvider implements AccumulatorProvider {
  
    private static final Logger LOG = LoggerFactory.getLogger(VoidAccumulatorProvider.class);
  
    private VoidAccumulatorProvider() {}
  
    public static Factory getFactory() {
      return Factory.get();
    }
  
    @Override
    public Counter getCounter(String name) {
      return VoidCounter.INSTANCE;
    }
  
    @Override
    public Counter getCounter(String namespace, String name) {
      return VoidCounter.INSTANCE;
    }
  
    @Override
    public Histogram getHistogram(String name) {
      return VoidHistogram.INSTANCE;
    }
  
    @Override
    public Histogram getHistogram(String namespace, String name) {
      return VoidHistogram.INSTANCE;
    }
  
    @Override
    public Timer getTimer(String name) {
      return VoidTimer.INSTANCE;
    }
  
    // ------------------------
  
    /** AccumulatorProvider Factory. */
    public static class Factory implements AccumulatorProvider.Factory {
  
      private static final Factory INSTANCE = new Factory();
  
      private static final AccumulatorProvider PROVIDER = new VoidAccumulatorProvider();
  
      private static final AtomicBoolean isLogged = new AtomicBoolean();
  
      private Factory() {}
  
      public static Factory get() {
        return INSTANCE;
      }
  
      @Override
      public AccumulatorProvider create() {
        if (isLogged.compareAndSet(false, true)) {
          LOG.warn("Using accumulators with VoidAccumulatorProvider will have no effect");
        }
        return PROVIDER;
      }
    }
  
    // ------------------------
  
    /** Empty implementation of Counter doesnt count anything. */
    private static class VoidCounter implements Counter {
  
      private static final VoidCounter INSTANCE = new VoidCounter();
  
      private VoidCounter() {}
  
      @Override
      public void increment(long value) {
        // NOOP
      }
  
      @Override
      public void increment() {
        // NOOP
      }
    }
  
    /** Empty implementation of Histogram doesnt count anything. */
    public static class VoidHistogram implements Histogram {
  
      private static final VoidHistogram INSTANCE = new VoidHistogram();
  
      private VoidHistogram() {}
  
      @Override
      public void add(long value) {
        // NOOP
      }
  
      @Override
      public void add(long value, long times) {
        // NOOP
      }
    }
  
    /** Empty implementation of Timer doesnt measure anything. */
    public static class VoidTimer implements Timer {
  
      private static final VoidTimer INSTANCE = new VoidTimer();
  
      private VoidTimer() {}
  
      @Override
      public void add(Duration duration) {
        // NOOP
      }
    }
  }
  