hadoop Retryer 源码

haddop Retryer 代码

文件路径：/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/impl/prefetch/Retryer.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.impl.prefetch;

import static org.apache.hadoop.fs.impl.prefetch.Validate.checkGreater;
import static org.apache.hadoop.fs.impl.prefetch.Validate.checkPositiveInteger;

/**
 * Provides retry related functionality.
 */
public class Retryer {

  /* Maximum amount of delay (in ms) before retry fails. */
  private int maxDelay;

  /* Per retry delay (in ms). */
  private int perRetryDelay;

  /**
   * The time interval (in ms) at which status update would be made.
   */
  private int statusUpdateInterval;

  /* Current delay. */
  private int delay;

  /**
   * Initializes a new instance of the {@code Retryer} class.
   *
   * @param perRetryDelay per retry delay (in ms).
   * @param maxDelay maximum amount of delay (in ms) before retry fails.
   * @param statusUpdateInterval time interval (in ms) at which status update would be made.
   *
   * @throws IllegalArgumentException if perRetryDelay is zero or negative.
   * @throws IllegalArgumentException if maxDelay is less than or equal to perRetryDelay.
   * @throws IllegalArgumentException if statusUpdateInterval is zero or negative.
   */
  public Retryer(int perRetryDelay, int maxDelay, int statusUpdateInterval) {
    checkPositiveInteger(perRetryDelay, "perRetryDelay");
    checkGreater(maxDelay, "maxDelay", perRetryDelay, "perRetryDelay");
    checkPositiveInteger(statusUpdateInterval, "statusUpdateInterval");

    this.perRetryDelay = perRetryDelay;
    this.maxDelay = maxDelay;
    this.statusUpdateInterval = statusUpdateInterval;
  }

  /**
   * Returns true if retrying should continue, false otherwise.
   *
   * @return true if the caller should retry, false otherwise.
   */
  public boolean continueRetry() {
    if (this.delay >= this.maxDelay) {
      return false;
    }

    try {
      Thread.sleep(this.perRetryDelay);
    } catch (InterruptedException e) {
      // Ignore the exception as required by the semantic of this class;
    }

    this.delay += this.perRetryDelay;
    return true;
  }

  /**
   * Returns true if status update interval has been reached.
   *
   * @return true if status update interval has been reached.
   */
  public boolean updateStatus() {
    return (this.delay > 0) && this.delay % this.statusUpdateInterval == 0;
  }
}

相关信息

hadoop 源码目录

相关文章

hadoop BlockCache 源码

hadoop BlockData 源码

hadoop BlockManager 源码

hadoop BlockOperations 源码

hadoop BoundedResourcePool 源码

hadoop BufferData 源码

hadoop BufferPool 源码

hadoop CachingBlockManager 源码

hadoop EmptyPrefetchingStatistics 源码

hadoop ExecutorServiceFuturePool 源码