AtlasDistributionSummaryTest.java

/*
 * Copyright 2014-2016 Netflix, Inc.
 *
 * Licensed 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 com.netflix.spectator.atlas;

import com.netflix.spectator.api.DefaultRegistry;
import com.netflix.spectator.api.Id;
import com.netflix.spectator.api.ManualClock;
import com.netflix.spectator.api.Measurement;
import com.netflix.spectator.api.Registry;
import com.netflix.spectator.api.Utils;
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;


@RunWith(JUnit4.class)
public class AtlasDistributionSummaryTest {

  private ManualClock clock = new ManualClock();
  private Registry registry = new DefaultRegistry();
  private long step = 10000L;
  private AtlasDistributionSummary dist = new AtlasDistributionSummary(registry.createId("test"), clock, step);

  private void checkValue(long count, long amount, long square, long max) {
    int num = 0;
    for (Measurement m : dist.measure()) {
      String stat = Utils.getTagValue(m.id(), "statistic");
      DsType ds = "max".equals(stat) ? DsType.gauge : DsType.rate;
      Id expectedId = dist.id().withTag(ds).withTag("statistic", stat);
      Assert.assertEquals(expectedId, m.id());
      switch (stat) {
        case "count":
          Assert.assertEquals(count / 10.0, m.value(), 1e-12);
          break;
        case "totalAmount":
          Assert.assertEquals(amount / 10.0, m.value(), 1e-12);
          break;
        case "totalOfSquares":
          Assert.assertEquals(square / 10.0, m.value(), 1e-12);
          break;
        case "max":
          Assert.assertEquals(max, m.value(), 1e-12);
          break;
        default:
          throw new IllegalArgumentException("unknown stat: " + stat);
      }
      Assert.assertEquals(count, dist.count());
      Assert.assertEquals(amount, dist.totalAmount());
      ++num;
    }
    Assert.assertEquals(4, num);
  }

  @Test
  public void measuredIdHasDsType() {
    checkValue(0, 0, 0, 0);
  }

  @Test
  public void recordOne() {
    dist.record(1);
    checkValue(0, 0, 0, 0);

    clock.setWallTime(step + 1);
    checkValue(1, 1, 1, 1);
  }

  @Test
  public void recordTwo() {
    dist.record(2);
    checkValue(0, 0, 0, 0);

    clock.setWallTime(step + 1);
    checkValue(1, 2, 4, 2);
  }

  @Test
  public void recordZero() {
    dist.record(0);
    clock.setWallTime(step + 1);
    checkValue(1, 0, 0, 0);
  }

  @Test
  public void recordNegativeValue() {
    dist.record(-2);
    clock.setWallTime(step + 1);
    checkValue(1, 0, 0, 0);
  }

  @Test
  public void recordSeveralValues() {
    dist.record(1);
    dist.record(2);
    dist.record(3);
    dist.record(1);
    clock.setWallTime(step + 1);
    checkValue(4, 1 + 2 + 3 + 1, 1 + 4 + 9 + 1, 3);
  }

  @Test
  public void rollForward() {
    dist.record(42);
    clock.setWallTime(step + 1);
    checkValue(1, 42, 42 * 42, 42);
    clock.setWallTime(step + step + 1);
    checkValue(0, 0, 0, 0);
  }
}