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.master;
20
21 import org.apache.hadoop.hbase.classification.InterfaceAudience;
22
23 /**
24 * Factory to create MetricsMasterSource when given a MetricsMasterWrapper
25 */
26 @InterfaceAudience.Private
27 public class MetricsMasterSourceFactoryImpl implements MetricsMasterSourceFactory {
28 private static enum FactoryStorage {
29 INSTANCE;
30 MetricsMasterSource masterSource;
31 }
32
33 @Override
34 public synchronized MetricsMasterSource create(MetricsMasterWrapper masterWrapper) {
35 if (FactoryStorage.INSTANCE.masterSource == null) {
36 FactoryStorage.INSTANCE.masterSource = new MetricsMasterSourceImpl(masterWrapper);
37 }
38 return FactoryStorage.INSTANCE.masterSource;
39 }
40 }