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.hbase.master;
019
020import java.io.Serializable;
021import java.util.Comparator;
022
023import org.apache.hadoop.hbase.ServerName;
024import org.apache.hadoop.hbase.client.RegionInfo;
025import org.apache.yetus.audience.InterfaceAudience;
026import org.apache.yetus.audience.InterfaceStability;
027
028/**
029 * Stores the plan for the move of an individual region.
030 *
031 * Contains info for the region being moved, info for the server the region
032 * should be moved from, and info for the server the region should be moved
033 * to.
034 *
035 * The comparable implementation of this class compares only the region
036 * information and not the source/dest server info.
037 */
038@InterfaceAudience.LimitedPrivate("Coprocessors")
039@InterfaceStability.Evolving
040public class RegionPlan implements Comparable<RegionPlan> {
041  private final RegionInfo hri;
042  private final ServerName source;
043  private ServerName dest;
044
045  public static class RegionPlanComparator implements Comparator<RegionPlan>, Serializable {
046    private static final long serialVersionUID = 4213207330485734853L;
047
048    @Override
049    public int compare(RegionPlan l, RegionPlan r) {
050      return RegionPlan.compareTo(l, r);
051    }
052  }
053
054  /**
055   * Instantiate a plan for a region move, moving the specified region from
056   * the specified source server to the specified destination server.
057   *
058   * Destination server can be instantiated as null and later set
059   * with {@link #setDestination(ServerName)}.
060   *
061   * @param hri region to be moved
062   * @param source regionserver region should be moved from
063   * @param dest regionserver region should be moved to
064   */
065  public RegionPlan(final RegionInfo hri, ServerName source, ServerName dest) {
066    this.hri = hri;
067    this.source = source;
068    this.dest = dest;
069  }
070
071  /**
072   * Set the destination server for the plan for this region.
073   */
074  public void setDestination(ServerName dest) {
075    this.dest = dest;
076  }
077
078  /**
079   * Get the source server for the plan for this region.
080   * @return server info for source
081   */
082  public ServerName getSource() {
083    return source;
084  }
085
086  /**
087   * Get the destination server for the plan for this region.
088   * @return server info for destination
089   */
090  public ServerName getDestination() {
091    return dest;
092  }
093
094  /**
095   * Get the encoded region name for the region this plan is for.
096   * @return Encoded region name
097   */
098  public String getRegionName() {
099    return this.hri.getEncodedName();
100  }
101
102  public RegionInfo getRegionInfo() {
103    return this.hri;
104  }
105
106  /**
107   * Compare the region info.
108   * @param other region plan you are comparing against
109   */
110  @Override
111  public int compareTo(RegionPlan other) {
112    return compareTo(this, other);
113  }
114
115  private static int compareTo(RegionPlan left, RegionPlan right) {
116    int result = compareServerName(left.source, right.source);
117    if (result != 0) {
118      return result;
119    }
120    if (left.hri == null) {
121      if (right.hri != null) {
122        return -1;
123      }
124    } else if (right.hri == null) {
125      return +1;
126    } else {
127      result = RegionInfo.COMPARATOR.compare(left.hri, right.hri);
128    }
129    if (result != 0) {
130      return result;
131    }
132    return compareServerName(left.dest, right.dest);
133  }
134
135  private static int compareServerName(ServerName left, ServerName right) {
136    if (left == null) {
137      return right == null? 0: -1;
138    } else if (right == null) {
139      return +1;
140    }
141    return left.compareTo(right);
142  }
143
144  @Override
145  public int hashCode() {
146    final int prime = 31;
147    int result = 1;
148    result = prime * result + ((dest == null) ? 0 : dest.hashCode());
149    result = prime * result + ((hri == null) ? 0 : hri.hashCode());
150    result = prime * result + ((source == null) ? 0 : source.hashCode());
151    return result;
152  }
153
154  @Override
155  public boolean equals(Object obj) {
156    if (this == obj) {
157      return true;
158    }
159    if (obj == null) {
160      return false;
161    }
162    if (getClass() != obj.getClass()) {
163      return false;
164    }
165    RegionPlan other = (RegionPlan) obj;
166    if (dest == null) {
167      if (other.dest != null) {
168        return false;
169      }
170    } else if (!dest.equals(other.dest)) {
171      return false;
172    }
173    if (hri == null) {
174      if (other.hri != null) {
175        return false;
176      }
177    } else if (!hri.equals(other.hri)) {
178      return false;
179    }
180    if (source == null) {
181      if (other.source != null) {
182        return false;
183      }
184    } else if (!source.equals(other.source)) {
185      return false;
186    }
187    return true;
188  }
189
190  @Override
191  public String toString() {
192    return "hri=" + this.hri.getEncodedName() + ", source=" +
193      (this.source == null? "": this.source.toString()) +
194      ", destination=" + (this.dest == null? "": this.dest.toString());
195  }
196}