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BAEL-2033 Stream Ordering (#4965)

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Sam Millington 2018-08-23 15:49:31 +01:00 committed by Josh Cummings
parent e77e8c0025
commit 2639324919
3 changed files with 279 additions and 0 deletions
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34
testing-modules/streams-ordering/pom.xml Normal file
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<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.baeldung</groupId>
<artifactId>StreamsOrdering</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.openjdk.jmh/jmh-core -->
<dependency>
<groupId>org.openjdk.jmh</groupId>
<artifactId>jmh-core</artifactId>
<version>1.21</version>
</dependency>
<dependency>
<groupId>org.openjdk.jmh</groupId>
<artifactId>jmh-generator-annprocess</artifactId>
<version>1.21</version>
<scope>provided</scope>
</dependency>
</dependencies>
</project>

148
testing-modules/streams-ordering/src/test/java/StreamsOrderingTest.java Normal file
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import org.junit.Before;
import org.junit.Test;
import java.util.*;
import java.util.function.Function;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.stream.Collectors;
import java.util.stream.IntStream;
import static org.junit.Assert.assertEquals;
public class StreamsOrderingTest {
Logger logger = Logger.getLogger( StreamsOrderingTest.class.getName());
@Before
public void setUp() throws Exception {
logger.setLevel(Level.ALL);
}
@Test
public void givenTwoCollections_whenStreamed_thenCheckOutputDifferent(){
List<String> list = Arrays.asList("B", "A", "C", "D", "F");
Set<String> set = new TreeSet<>(Arrays.asList("B", "A", "C", "D", "F"));
Object[] listOutput = list.stream().toArray();
Object[] setOutput = set.stream().toArray();
assertEquals("[B, A, C, D, F]", Arrays.toString(listOutput));
assertEquals("[A, B, C, D, F]", Arrays.toString(setOutput));
}
@Test
public void givenTwoCollections_whenStreamedInParallel_thenCheckOutputDifferent(){
List<String> list = Arrays.asList("B", "A", "C", "D", "F");
Set<String> set = new TreeSet<>(Arrays.asList("B", "A", "C", "D", "F"));
Object[] listOutput = list.stream().parallel().toArray();
Object[] setOutput = set.stream().parallel().toArray();
assertEquals("[B, A, C, D, F]", Arrays.toString(listOutput));
assertEquals("[A, B, C, D, F]", Arrays.toString(setOutput));
}
@Test
public void givenOrderedInput_whenUnorderedAndOrderedCompared_thenCheckUnorderedOutputChanges(){
Set<Integer> set = new TreeSet<>(
Arrays.asList(-9, -5, -4, -2, 1, 2, 4, 5, 7, 9, 12, 13, 16, 29, 23, 34, 57, 68, 90, 102, 230));
Object[] orderedArray = set.stream()
.parallel()
.limit(5)
.toArray();
Object[] unorderedArray = set.stream()
.unordered()
.parallel()
.limit(5)
.toArray();
logger.info(Arrays.toString(orderedArray));
logger.info(Arrays.toString(unorderedArray));
}
@Test
public void givenUnsortedStreamInput_whenStreamSorted_thenCheckOrderChanged(){
List<Integer> list = Arrays.asList(-3,10,-4,1,3);
Object[] listOutput = list.stream().toArray();
Object[] listOutputSorted = list.stream().sorted().toArray();
assertEquals("[-3, 10, -4, 1, 3]", Arrays.toString(listOutput));
assertEquals("[-4, -3, 1, 3, 10]", Arrays.toString(listOutputSorted));
}
@Test
public void givenUnsortedStreamInput_whenStreamDistinct_thenShowTimeTaken(){
long start, end;
start = System.currentTimeMillis();
IntStream.range(1,1_000_000).unordered().parallel().distinct().toArray();
end = System.currentTimeMillis();
System.out.println(String.format("Time taken when unordered: %d ms", (end - start)));
}
@Test
public void givenSameCollection_whenStreamTerminated_thenCheckEachVsEachOrdered(){
List<String> list = Arrays.asList("B", "A", "C", "D", "F");
list.stream().parallel().forEach(e -> logger.log(Level.INFO, e));
list.stream().parallel().forEachOrdered(e -> logger.log(Level.INFO, e));
}
@Test
public void givenSameCollection_whenStreamCollected_thenCheckOutput(){
List<String> list = Arrays.asList("B", "A", "C", "D", "F");
List<String> collectionList = list.stream().parallel().collect(Collectors.toList());
Set<String> collectionSet = list.stream().parallel().collect(Collectors.toCollection(TreeSet::new));
assertEquals("[B, A, C, D, F]", collectionList.toString());
assertEquals("[A, B, C, D, F]", collectionSet.toString());
}
@Test
public void givenListIterationOrder_whenStreamCollectedToMap_thenCeckOrderChanged() {
List<String> list = Arrays.asList("A", "BB", "CCC");
Map<String, Integer> hashMap = list.stream().collect(Collectors.toMap(Function.identity(), String::length));
Object[] keySet = hashMap.keySet().toArray();
assertEquals("[BB, A, CCC]", Arrays.toString(keySet));
}
@Test
public void givenListIteration_whenStreamCollectedtoHashMap_thenCheckOrderMaintained() {
List<String> list = Arrays.asList("A", "BB", "CCC", "CCC");
Map<String, Integer> linkedHashMap = list.stream().collect(Collectors.toMap(
Function.identity(),
String::length,
(u, v) -> u,
LinkedHashMap::new
));
Object[] keySet = linkedHashMap.keySet().toArray();
assertEquals("[A, BB, CCC]", Arrays.toString(keySet));
}
}

97
testing-modules/streams-ordering/src/test/java/benchmarking/TestBenchmark.java Normal file
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package benchmarking;
import org.junit.Test;
import org.openjdk.jmh.annotations.*;
import org.openjdk.jmh.infra.Blackhole;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;
import org.openjdk.jmh.runner.options.TimeValue;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.concurrent.TimeUnit;
import java.util.stream.IntStream;
public class TestBenchmark
{
@Test
public void
launchBenchmark() throws Exception {
Options opt = new OptionsBuilder()
// Specify which benchmarks to run.
// You can be more specific if you'd like to run only one benchmark per test.
.include(this.getClass().getName() + ".*")
// Set the following options as needed
.mode (Mode.AverageTime)
.timeUnit(TimeUnit.MICROSECONDS)
.warmupTime(TimeValue.seconds(1))
.warmupIterations(2)
.measurementTime(TimeValue.seconds(1))
.measurementIterations(2)
.threads(2)
.forks(1)
.shouldFailOnError(true)
.shouldDoGC(true)
//.jvmArgs("-XX:+UnlockDiagnosticVMOptions", "-XX:+PrintInlining")
//.addProfiler(WinPerfAsmProfiler.class)
.build();
new Runner(opt).run();
}
@Benchmark
public void givenOrderedStreamInput_whenStreamFiltered_showOpsPerMS(){
IntStream.range(1, 100_000_000).parallel().filter(i -> i % 10 == 0).toArray();
}
@Benchmark
public void givenUnorderedStreamInput_whenStreamFiltered_showOpsPerMS(){
IntStream.range(1,100_000_000).unordered().parallel().filter(i -> i % 10 == 0).toArray();
}
@Benchmark
public void givenUnorderedStreamInput_whenStreamDistinct_showOpsPerMS(){
IntStream.range(1, 1_000_000).unordered().parallel().distinct().toArray();
}
@Benchmark
public void givenOrderedStreamInput_whenStreamDistinct_showOpsPerMS() {
//section 5.1.
IntStream.range(1, 1_000_000).parallel().distinct().toArray();
}
// The JMH samples are the best documentation for how to use it
// http://hg.openjdk.java.net/code-tools/jmh/file/tip/jmh-samples/src/main/java/org/openjdk/jmh/samples/
@State(Scope.Thread)
public static class BenchmarkState
{
List<Integer> list;
@Setup(Level.Trial) public void
initialize() {
Random rand = new Random();
list = new ArrayList<>();
for (int i = 0; i < 1000; i++)
list.add (rand.nextInt());
}
}
@Benchmark public void
benchmark1 (BenchmarkState state, Blackhole bh) {
List<Integer> list = state.list;
for (int i = 0; i < 1000; i++)
bh.consume (list.get (i));
}
}