/*
* Copyright (C) 2011 Clearspring Technologies, 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.clearspring.analytics.stream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectInputStream;
import java.io.ObjectOutput;
import java.io.ObjectOutputStream;
import java.util.Arrays;
import java.util.List;
import org.junit.Test;
import cern.jet.random.Distributions;
import cern.jet.random.engine.RandomEngine;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
public class TestStreamSummary {
private static final int NUM_ITERATIONS = 100000;
@Test
public void testStreamSummary() {
StreamSummary<String> vs = new StreamSummary<String>(3);
String[] stream = {"X", "X", "Y", "Z", "A", "B", "C", "X", "X", "A", "A", "A"};
for (String i : stream) {
vs.offer(i);
/*
for(String s : vs.poll(3))
System.out.print(s+" ");
*/
System.out.println(vs);
}
}
@Test
public void testTopK() {
StreamSummary<String> vs = new StreamSummary<String>(3);
String[] stream = {"X", "X", "Y", "Z", "A", "B", "C", "X", "X", "A", "C", "A", "A"};
for (String i : stream) {
vs.offer(i);
}
List<Counter<String>> topK = vs.topK(3);
for (Counter<String> c : topK) {
assertTrue(Arrays.asList("A", "C", "X").contains(c.getItem()));
}
}
@Test
public void testTopKWithIncrement() {
StreamSummary<String> vs = new StreamSummary<String>(3);
String[] stream = {"X", "X", "Y", "Z", "A", "B", "C", "X", "X", "A", "C", "A", "A"};
for (String i : stream) {
vs.offer(i, 10);
}
List<Counter<String>> topK = vs.topK(3);
for (Counter<String> c : topK) {
assertTrue(Arrays.asList("A", "C", "X").contains(c.getItem()));
}
}
@Test
public void testTopKWithIncrementOutOfOrder() {
StreamSummary<String> vs_increment = new StreamSummary<String>(3);
StreamSummary<String> vs_single = new StreamSummary<String>(3);
String[] stream = {"A", "B", "C", "D", "A"};
Integer[] increments = {15, 20, 25, 30, 1};
for (int i = 0; i < stream.length; i++) {
vs_increment.offer(stream[i], increments[i]);
for (int k = 0; k < increments[i]; k++) {
vs_single.offer(stream[i]);
}
}
System.out.println("Insert with counts vs. single inserts:");
System.out.println(vs_increment);
System.out.println(vs_single);
List<Counter<String>> topK_increment = vs_increment.topK(3);
List<Counter<String>> topK_single = vs_single.topK(3);
for (int i = 0; i < topK_increment.size(); i++) {
assertEquals(topK_increment.get(i).getItem(),
topK_single.get(i).getItem());
}
}
@Test
public void testGeometricDistribution() {
StreamSummary<Integer> vs = new StreamSummary<Integer>(10);
RandomEngine re = RandomEngine.makeDefault();
for (int i = 0; i < NUM_ITERATIONS; i++) {
int z = Distributions.nextGeometric(0.25, re);
vs.offer(z);
}
List<Integer> top = vs.peek(5);
System.out.println("Geometric:");
for (Integer e : top) {
System.out.println(e);
}
int tippyTop = top.get(0);
assertEquals(0, tippyTop);
System.out.println(vs);
}
@SuppressWarnings("unchecked")
@Test
public void testCounterSerialization() throws IOException, ClassNotFoundException {
StreamSummary<String> vs = new StreamSummary<String>(3);
String[] stream = {"X", "X", "Y", "Z", "A", "B", "C", "X", "X", "A", "C", "A", "A"};
for (String i : stream) {
vs.offer(i);
}
List<Counter<String>> topK = vs.topK(3);
for (Counter<String> c : topK) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutput oo = new ObjectOutputStream(baos);
oo.writeObject(c);
oo.close();
ObjectInput oi = new ObjectInputStream(new ByteArrayInputStream(baos.toByteArray()));
Counter<String> clone = (Counter<String>) oi.readObject();
assertEquals(c.getCount(), clone.getCount());
assertEquals(c.getError(), clone.getError());
assertEquals(c.getItem(), clone.getItem());
}
}
@SuppressWarnings("unchecked")
@Test
public void testSerialization() throws IOException, ClassNotFoundException {
StreamSummary<String> vs = new StreamSummary<String>(3);
String[] stream = {"X", "X", "Y", "Z", "A", "B", "C", "X", "X", "A", "C", "A", "A"};
for (String i : stream) {
vs.offer(i);
}
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutput oo = new ObjectOutputStream(baos);
oo.writeObject(vs);
oo.close();
ObjectInput oi = new ObjectInputStream(new ByteArrayInputStream(baos.toByteArray()));
StreamSummary<String> clone = (StreamSummary<String>) oi.readObject();
assertEquals(vs.toString(), clone.toString());
}
@Test
public void testByteSerialization() throws IOException, ClassNotFoundException {
StreamSummary<String> vs = new StreamSummary<String>(3);
String[] stream = {"X", "X", "Y", "Z", "A", "B", "C", "X", "X", "A", "C", "A", "A"};
for (String i : stream) {
vs.offer(i);
}
testSerialization(vs);
// Empty
vs = new StreamSummary<String>(0);
testSerialization(vs);
}
private void testSerialization(StreamSummary<?> vs) throws IOException, ClassNotFoundException {
byte[] bytes = vs.toBytes();
StreamSummary<String> clone = new StreamSummary<String>(bytes);
assertEquals(vs.toString(), clone.toString());
}
}