hadoop EmptyIOStatistics 源码

  • 2022-10-20
  • 浏览 (264)

haddop EmptyIOStatistics 代码

文件路径:/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/impl/EmptyIOStatistics.java

/*
 * 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.hadoop.fs.statistics.impl;

import java.util.Map;

import org.apache.hadoop.fs.statistics.IOStatistics;
import org.apache.hadoop.fs.statistics.MeanStatistic;

import static java.util.Collections.emptyMap;

/**
 * An empty IO Statistics implementation for classes which always
 * want to return a non-null set of statistics.
 */
final class EmptyIOStatistics extends AbstractIOStatisticsImpl {

  /**
   * The sole instance of this class.
   */
  private static final EmptyIOStatistics INSTANCE = new EmptyIOStatistics();

  private EmptyIOStatistics() {
  }

  @Override
  public Map<String, Long> counters() {
    return emptyMap();
  }

  @Override
  public Map<String, Long> gauges() {
    return emptyMap();
  }

  @Override
  public Map<String, Long> minimums() {
    return emptyMap();
  }

  @Override
  public Map<String, Long> maximums() {
    return emptyMap();
  }

  @Override
  public Map<String, MeanStatistic> meanStatistics() {
    return emptyMap();
  }

  /**
   * Get the single instance of this class.
   * @return a shared, empty instance.
   */
  public static IOStatistics getInstance() {
    return INSTANCE;
  }
}

相关信息

hadoop 源码目录

相关文章

hadoop AbstractIOStatisticsImpl 源码

hadoop DynamicIOStatistics 源码

hadoop DynamicIOStatisticsBuilder 源码

hadoop EmptyIOStatisticsContextImpl 源码

hadoop EmptyIOStatisticsStore 源码

hadoop EvaluatingStatisticsMap 源码

hadoop IOStatisticsBinding 源码

hadoop IOStatisticsContextImpl 源码

hadoop IOStatisticsContextIntegration 源码

hadoop IOStatisticsStore 源码

0  赞