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.flink.translation.utils;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.function.Supplier;
  import org.apache.beam.runners.core.metrics.DistributionCell;
  
  /** Helpers for reporting checkpoint durations. */
  public class CheckpointStats {
  
    /** Checkpoint id => Checkpoint start (System.currentTimeMillis()). */
    private final Map<Long, Long> checkpointDurations = new HashMap<>();
    /** Distribution cell for reporting checkpoint durations. */
    private final Supplier<DistributionCell> distributionCellSupplier;
  
    public CheckpointStats(Supplier<DistributionCell> distributionCellSupplier) {
      this.distributionCellSupplier = distributionCellSupplier;
    }
  
    public void snapshotStart(long checkpointId) {
      checkpointDurations.put(checkpointId, System.currentTimeMillis());
    }
  
    public void reportCheckpointDuration(long checkpointId) {
      Long checkpointStart = checkpointDurations.remove(checkpointId);
      if (checkpointStart != null) {
        long checkpointDuration = System.currentTimeMillis() - checkpointStart;
        distributionCellSupplier.get().update(checkpointDuration);
      }
    }
  }
  