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 =
038      HBaseClassTestRule.forClass(TestGauge.class);
039
040  @Test
041  public void testGetValue() {
042    SimpleGauge gauge = new SimpleGauge();
043
044    assertEquals(0, (long)gauge.getValue());
045
046    gauge.setValue(1000L);
047
048    assertEquals(1000L, (long)gauge.getValue());
049  }
050
051  /**
052   * Gauge implementation with a setter.
053   */
054  private static class SimpleGauge implements Gauge<Long> {
055
056    private final AtomicLong value = new AtomicLong(0L);
057
058    @Override public Long getValue() {
059      return this.value.get();
060    }
061
062    public void setValue(long value) {
063      this.value.set(value);
064    }
065  }
066}