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}