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