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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  package org.apache.hadoop.hbase.metrics.impl;
19  
20  import org.apache.hadoop.hbase.classification.InterfaceAudience;
21  import org.apache.hadoop.hbase.metrics.Counter;
22  import org.apache.hadoop.hbase.util.LongAdder;
23  
24  /**
25   * Custom implementation of {@link org.apache.hadoop.hbase.metrics.Counter} using LongAdder.
26   */
27  @InterfaceAudience.Private
28  public class CounterImpl implements Counter {
29  
30    private final LongAdder counter;
31  
32    public CounterImpl() {
33      this.counter = new LongAdder();
34    }
35  
36    @Override
37    public void increment() {
38      this.counter.increment();
39    }
40  
41    @Override
42    public void increment(long n) {
43      this.counter.add(n);
44    }
45  
46    @Override
47    public void decrement() {
48      this.counter.decrement();
49    }
50  
51    @Override
52    public void decrement(long n) {
53      this.counter.add(-n);
54    }
55  
56    @Override
57    public long getCount() {
58      return this.counter.sum();
59    }
60  }