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.balancer; 019 020import org.apache.yetus.audience.InterfaceAudience; 021 022/** 023 * An action to move or swap a region 024 */ 025@InterfaceAudience.Private 026abstract class BalanceAction { 027 enum Type { 028 ASSIGN_REGION, 029 MOVE_REGION, 030 SWAP_REGIONS, 031 NULL, 032 } 033 034 static final BalanceAction NULL_ACTION = new BalanceAction(Type.NULL) { 035 }; 036 037 private final Type type; 038 039 BalanceAction(Type type) { 040 this.type = type; 041 } 042 043 /** 044 * Returns an Action which would undo this action 045 */ 046 BalanceAction undoAction() { 047 return this; 048 } 049 050 Type getType() { 051 return type; 052 } 053 054 @Override 055 public String toString() { 056 return type + ":"; 057 } 058}