/**
* 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.hdfs.server.common;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.util.SequentialNumber;
/****************************************************************
* A GenerationStamp is a Hadoop FS primitive, identified by a long.
****************************************************************/
@InterfaceAudience.Private
public class GenerationStamp extends SequentialNumber {
/**
* The last reserved generation stamp.
*/
public static final long LAST_RESERVED_STAMP = 1000L;
/**
* Generation stamp of blocks that pre-date the introduction
* of a generation stamp.
*/
public static final long GRANDFATHER_GENERATION_STAMP = 0;
/**
* Create a new instance, initialized to {@link #LAST_RESERVED_STAMP}.
*/
public GenerationStamp() {
super(LAST_RESERVED_STAMP);
}
}