content: /*
   * 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.cassandra.metrics;
  
  import java.util.concurrent.TimeUnit;
  
  import org.junit.Test;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  
  public class LatencyMetricsTest
  {
      private final MetricNameFactory factory = new TestMetricsNameFactory();
  
      private static class TestMetricsNameFactory implements MetricNameFactory
      {
  
          @Override
          public CassandraMetricsRegistry.MetricName createMetricName(String metricName)
          {
              return new CassandraMetricsRegistry.MetricName(DefaultNameFactory.GROUP_NAME, ClientRequestMetrics.TYPE_NAME, metricName);
          }
      }
  
      /**
       * Test bitsets in a "real-world" environment, i.e., bloom filters
       */
      @Test
      public void testGetRecentLatency()
      {
          final LatencyMetrics l = new LatencyMetrics(ClientRequestMetrics.TYPE_NAME, "test");
          Runnable r = () -> {
              for (int i = 0; i < 10000; i++)
              {
                  l.addNano(1000);
              }
          };
          new Thread(r).start();
  
          for (int i = 0; i < 10000; i++)
          {
              Double recent = l.latency.getOneMinuteRate();
              assertFalse(recent.equals(Double.POSITIVE_INFINITY));
          }
      }
  
      /**
       * Test that parent LatencyMetrics are receiving updates from child metrics when reading
       */
      @Test
      public void testReadMerging()
      {
          final LatencyMetrics parent = new LatencyMetrics(ClientRequestMetrics.TYPE_NAME, "testMerge");
          final LatencyMetrics child = new LatencyMetrics(factory, "testChild", parent);
  
          for (int i = 0; i < 100; i++)
          {
              child.addNano(TimeUnit.NANOSECONDS.convert(i, TimeUnit.MILLISECONDS));
          }
  
          assertEquals(4950000, child.totalLatency.getCount());
          assertEquals(child.totalLatency.getCount(), parent.totalLatency.getCount());
          assertEquals(child.latency.getSnapshot().getMean(), parent.latency.getSnapshot().getMean(), 50D);
  
          child.release();
          parent.release();
      }
  
      @Test
      public void testRelease()
      {
          final LatencyMetrics parent = new LatencyMetrics(ClientRequestMetrics.TYPE_NAME, "testRelease");
          final LatencyMetrics child = new LatencyMetrics(factory, "testChildRelease", parent);
  
          for (int i = 0; i < 100; i++)
          {
              child.addNano(TimeUnit.NANOSECONDS.convert(i, TimeUnit.MILLISECONDS));
          }
  
          double mean = parent.latency.getSnapshot().getMean();
          long count = parent.totalLatency.getCount();
  
          child.release();
  
          // Check that no value was lost with the release
          assertEquals(count, parent.totalLatency.getCount());
          assertEquals(mean, parent.latency.getSnapshot().getMean(), 50D);
  
          parent.release();
      }
  }
  