001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hdfs.server.protocol;
019
020import org.apache.hadoop.hdfs.protocol.HdfsConstants;
021
022import com.google.common.base.Function;
023import com.google.common.collect.ComparisonChain;
024
025public class RemoteEditLog implements Comparable<RemoteEditLog> {
026  private long startTxId = HdfsConstants.INVALID_TXID;
027  private long endTxId = HdfsConstants.INVALID_TXID;
028  private boolean isInProgress = false;
029  
030  public RemoteEditLog() {
031  }
032
033  public RemoteEditLog(long startTxId, long endTxId) {
034    this.startTxId = startTxId;
035    this.endTxId = endTxId;
036    this.isInProgress = (endTxId == HdfsConstants.INVALID_TXID);
037  }
038  
039  public RemoteEditLog(long startTxId, long endTxId, boolean inProgress) {
040    this.startTxId = startTxId;
041    this.endTxId = endTxId;
042    this.isInProgress = inProgress;
043  }
044
045  public long getStartTxId() {
046    return startTxId;
047  }
048
049  public long getEndTxId() {
050    return endTxId;
051  }
052
053  public boolean isInProgress() {
054    return isInProgress;
055  }
056
057  @Override
058  public String toString() {
059    if (!isInProgress) {
060      return "[" + startTxId + "," + endTxId + "]";
061    } else {
062      return "[" + startTxId + "-? (in-progress)]";
063    }
064  }
065  
066  @Override
067  public int compareTo(RemoteEditLog log) {
068    return ComparisonChain.start()
069      .compare(startTxId, log.startTxId)
070      .compare(endTxId, log.endTxId)
071      .result();
072  }
073
074  @Override
075  public boolean equals(Object o) {
076    if (!(o instanceof RemoteEditLog)) return false;
077    return this.compareTo((RemoteEditLog)o) == 0;
078  }
079  
080  @Override
081  public int hashCode() {
082    return (int) (startTxId * endTxId);
083  }
084  
085  /**
086   * Guava <code>Function</code> which applies {@link #getStartTxId()} 
087   */
088  public static final Function<RemoteEditLog, Long> GET_START_TXID =
089    new Function<RemoteEditLog, Long>() {
090      @Override
091      public Long apply(RemoteEditLog log) {
092        if (null == log) {
093          return HdfsConstants.INVALID_TXID;
094        }
095        return log.getStartTxId();
096      }
097    };
098}