/**
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.hadoop.hbase.metrics.impl;
  
  import static org.junit.Assert.assertEquals;
  
  import java.util.concurrent.TimeUnit;
  
  import org.apache.hadoop.hbase.metrics.Timer;
  import org.apache.hadoop.hbase.testclassification.SmallTests;
  import org.junit.Before;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  
  /**
   * Test class for {@link TimerImpl}
   */
  @Category(SmallTests.class)
  public class TestTimerImpl {
  
    private Timer timer;
  
    @Before
    public void setup() {
      this.timer = new TimerImpl();
    }
  
    @Test
    public void testUpdate() {
      timer.update(40, TimeUnit.MILLISECONDS);
      timer.update(41, TimeUnit.MILLISECONDS);
      timer.update(42, TimeUnit.MILLISECONDS);
      assertEquals(3, timer.getHistogram().getCount());
      assertEquals(3, timer.getMeter().getCount());
  
      assertEquals(TimeUnit.MILLISECONDS.toMicros(41), timer.getHistogram().snapshot().getMedian());
    }
  }