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.celeborn.plugin.flink.metric;
  
  import org.apache.flink.metrics.Gauge;
  import org.apache.flink.metrics.View;
  import org.apache.flink.runtime.io.network.buffer.NetworkBufferPool;
  
  /**
   * This is a small hack. Instead of spawning a custom thread to monitor {@link NetworkBufferPool}
   * usage, we are re-using {@link View#update()} method for this purpose.
   */
  public class RequestedMemoryUsageMetric implements Gauge<Integer>, View {
  
    private final NetworkBufferPool networkBufferPool;
  
    public RequestedMemoryUsageMetric(NetworkBufferPool networkBufferPool) {
      this.networkBufferPool = networkBufferPool;
    }
  
    @Override
    public Integer getValue() {
      return networkBufferPool.getEstimatedRequestedSegmentsUsage();
    }
  
    @Override
    public void update() {
      networkBufferPool.maybeLogUsageWarning();
    }
  }
  