1 /**
2  * Licensed to the Apache Software Foundation (ASF) under one or more
3  * contributor license agreements. See the NOTICE file distributed with this
4  * work for additional information regarding copyright ownership. The ASF
5  * licenses this file to you under the Apache License, Version 2.0 (the
6  * "License"); you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
13  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
14  * License for the specific language governing permissions and limitations under
15  * the License.
16  */
17 package org.apache.hadoop.hdfs.server.namenode.startupprogress;
18 
19 import org.apache.hadoop.classification.InterfaceAudience;
20 
21 /**
22  * Abstract base of internal data structures used for tracking progress.  For
23  * primitive long properties, {@link Long#MIN_VALUE} is used as a sentinel value
24  * to indicate that the property is undefined.
25  */
26 @InterfaceAudience.Private
27 abstract class AbstractTracking implements Cloneable {
28   long beginTime = Long.MIN_VALUE;
29   long endTime = Long.MIN_VALUE;
30 
31   /**
32    * Subclass instances may call this method during cloning to copy the values of
33    * all properties stored in this base class.
34    *
35    * @param dest AbstractTracking destination for copying properties
36    */
copy(AbstractTracking dest)37   protected void copy(AbstractTracking dest) {
38     dest.beginTime = beginTime;
39     dest.endTime = endTime;
40   }
41 }
42