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;
019
020import java.io.IOException;
021
022import org.apache.hadoop.hbase.client.RegionInfo;
023import org.apache.yetus.audience.InterfaceAudience;
024
025/**
026 * The listener interface for receiving region state events.
027 */
028@InterfaceAudience.Private
029public interface RegionStateListener {
030// TODO: Get rid of this!!!! Ain't there a better way to watch region
031// state than introduce a whole new listening mechanism? St.Ack
032  /**
033   * Process region split event.
034   *
035   * @param hri An instance of RegionInfo
036   * @throws IOException
037   */
038  void onRegionSplit(RegionInfo hri) throws IOException;
039
040  /**
041   * Process region split reverted event.
042   *
043   * @param hri An instance of RegionInfo
044   * @throws IOException Signals that an I/O exception has occurred.
045   */
046  void onRegionSplitReverted(RegionInfo hri) throws IOException;
047
048  /**
049   * Process region merge event.
050   * @throws IOException
051   */
052  void onRegionMerged(RegionInfo mergedRegion) throws IOException;
053}