001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.metrics.impl;
019
020import static org.junit.Assert.assertEquals;
021
022import java.util.concurrent.atomic.AtomicLong;
023import org.apache.hadoop.hbase.HBaseClassTestRule;
024import org.apache.hadoop.hbase.metrics.Gauge;
025import org.apache.hadoop.hbase.testclassification.SmallTests;
026import org.junit.ClassRule;
027import org.junit.Test;
028import org.junit.experimental.categories.Category;
029
030/**
031 * Test class for {@link Gauge}.
032 */
033@Category(SmallTests.class)
034public class TestGauge {
035
036  @ClassRule
037  public static final HBaseClassTestRule CLASS_RULE = HBaseClassTestRule.forClass(TestGauge.class);
038
039  @Test
040  public void testGetValue() {
041    SimpleGauge gauge = new SimpleGauge();
042
043    assertEquals(0, (long) gauge.getValue());
044
045    gauge.setValue(1000L);
046
047    assertEquals(1000L, (long) gauge.getValue());
048  }
049
050  /**
051   * Gauge implementation with a setter.
052   */
053  private static class SimpleGauge implements Gauge<Long> {
054
055    private final AtomicLong value = new AtomicLong(0L);
056
057    @Override
058    public Long getValue() {
059      return this.value.get();
060    }
061
062    public void setValue(long value) {
063      this.value.set(value);
064    }
065  }
066}