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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.regionserver;
20  
21  /**
22   * Factory to create MetricsRegionServerSource when given a  MetricsRegionServerWrapper
23   */
24  public class MetricsRegionServerSourceFactoryImpl implements MetricsRegionServerSourceFactory {
25    public static enum FactoryStorage {
26      INSTANCE;
27      private Object aggLock = new Object();
28      private MetricsRegionAggregateSourceImpl aggImpl;
29    }
30  
31    private synchronized MetricsRegionAggregateSourceImpl getAggregate() {
32      synchronized (FactoryStorage.INSTANCE.aggLock) {
33        if (FactoryStorage.INSTANCE.aggImpl == null) {
34          FactoryStorage.INSTANCE.aggImpl = new MetricsRegionAggregateSourceImpl();
35        }
36        return FactoryStorage.INSTANCE.aggImpl;
37      }
38    }
39  
40  
41    @Override
42    public synchronized MetricsRegionServerSource createServer(MetricsRegionServerWrapper regionServerWrapper) {
43      return new MetricsRegionServerSourceImpl(regionServerWrapper);
44    }
45  
46    @Override
47    public MetricsRegionSource createRegion(MetricsRegionWrapper wrapper) {
48      return new MetricsRegionSourceImpl(wrapper, getAggregate());
49    }
50  }