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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 static org.junit.Assert.assertEquals;
21  
22  import java.util.concurrent.atomic.AtomicLong;
23  
24  import org.apache.hadoop.hbase.metrics.Gauge;
25  import org.apache.hadoop.hbase.testclassification.SmallTests;
26  import org.junit.Test;
27  import org.junit.experimental.categories.Category;
28  
29  /**
30   * Test class for {@link Gauge}.
31   */
32  @Category(SmallTests.class)
33  public class TestGauge {
34  
35    @Test
36    public void testGetValue() {
37      SimpleGauge gauge = new SimpleGauge();
38  
39      assertEquals(0, (long)gauge.getValue());
40  
41      gauge.setValue(1000L);
42  
43      assertEquals(1000L, (long)gauge.getValue());
44    }
45  
46    /**
47     * Gauge implementation with a setter.
48     */
49    private static class SimpleGauge implements Gauge<Long> {
50  
51      private final AtomicLong value = new AtomicLong(0L);
52  
53      @Override public Long getValue() {
54        return this.value.get();
55      }
56  
57      public void setValue(long value) {
58        this.value.set(value);
59      }
60    }
61  }