/*
* Licensed to the Ted Dunning under one or more contributor license
* agreements. See the NOTICE file that may be
* distributed with this work for additional information
* regarding copyright ownership. Ted Dunning 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 com.mapr.synth;
import com.google.common.collect.HashMultiset;
import com.google.common.collect.Multiset;
import org.junit.Test;
import java.util.Random;
import java.util.Set;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;
public class NestedRandomTest {
private static final int ITERATIONS = 20000;
@Test
public void testDefaultSeed() {
NestedRandom r0 = new NestedRandom();
NestedRandom r1 = new NestedRandom(0);
for (int i = 0; i < ITERATIONS; i++) {
assertEquals(r0.get(i).random().nextInt(), r1.get(i).random().nextInt());
}
}
@Test
public void testUniqueAndRepeatable() {
Multiset<Integer> samples = HashMultiset.create();
for (int seed = 0; seed < 20; seed++) {
NestedRandom origin = new NestedRandom(seed);
addSamples(samples, origin.get("a"));
addSamples(samples, origin.get("b"));
addSamples(samples, origin.get("c"));
addSamples(samples, origin.get("a"));
addSamples(samples, origin.get("b"));
addSamples(samples, origin.get("c"));
}
Multiset<Integer> counts = HashMultiset.create();
for (Integer x : samples.elementSet()) {
counts.add(samples.count(x));
}
Set<Integer> observedCounts = counts.elementSet();
assertEquals(2, observedCounts.size());
assertTrue(observedCounts.contains(2));
assertTrue(observedCounts.contains(4));
assertTrue(counts.count(4) < 1000);
assertTrue(counts.count(2) > 2e6);
}
private void addSamples(Multiset<Integer> samples, NestedRandom twig) {
int i = 0;
int sample = 0;
Random r = null;
for (NestedRandom leaf : twig) {
assertEquals(twig.get(i).random().nextDouble(), leaf.random().nextDouble(), 0);
r = leaf.random();
sample = r.nextInt();
samples.add(sample);
samples.add(leaf.get("q").random().nextInt());
if (++i > ITERATIONS) {
break;
}
}
assertNotNull(r);
Random rx = twig.get(ITERATIONS).random();
assertEquals(sample, rx.nextInt());
assertEquals(r.nextInt(), rx.nextInt());
}
}