1 /**
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19 package org.apache.hadoop.hbase.procedure2.store;
20
21 import java.util.concurrent.CopyOnWriteArrayList;
22 import java.util.concurrent.atomic.AtomicBoolean;
23
24 /**
25 * Base class for {@link ProcedureStore}s.
26 */
27 public abstract class ProcedureStoreBase implements ProcedureStore {
28 private final CopyOnWriteArrayList<ProcedureStoreListener> listeners =
29 new CopyOnWriteArrayList<ProcedureStoreListener>();
30
31 private final AtomicBoolean running = new AtomicBoolean(false);
32
33 /**
34 * Change the state to 'isRunning',
35 * returns true if the store state was changed,
36 * false if the store was already in that state.
37 * @param isRunning the state to set.
38 * @return true if the store state was changed, otherwise false.
39 */
40 protected boolean setRunning(boolean isRunning) {
41 return running.getAndSet(isRunning) != isRunning;
42 }
43
44 @Override
45 public boolean isRunning() {
46 return running.get();
47 }
48
49 @Override
50 public void registerListener(ProcedureStoreListener listener) {
51 listeners.add(listener);
52 }
53
54 @Override
55 public boolean unregisterListener(ProcedureStoreListener listener) {
56 return listeners.remove(listener);
57 }
58
59 protected void sendPostSyncSignal() {
60 if (!this.listeners.isEmpty()) {
61 for (ProcedureStoreListener listener : this.listeners) {
62 listener.postSync();
63 }
64 }
65 }
66
67 protected void sendAbortProcessSignal() {
68 if (!this.listeners.isEmpty()) {
69 for (ProcedureStoreListener listener : this.listeners) {
70 listener.abortProcess();
71 }
72 }
73 }
74 }