Examples with Spliterator java8.util.Spliterator used on opensource projects

Example 16 with Spliterator

use of java8.util.Spliterator in project streamsupport by stefan-zobel.

the class Collection8Test method testRandomElementRemovalDuringTraversal.

/**
 * Some elements randomly disappear in the middle of traversal.
 */
@SuppressWarnings({ "rawtypes", "unchecked" })
@Test(dataProvider = "Source")
public void testRandomElementRemovalDuringTraversal(String description, Supplier<CollectionImplementation> sci) {
    CollectionImplementation impl = sci.get();
    if (CopyOnWriteArrayList.class.equals(impl.klazz()) || CopyOnWriteArraySet.class.equals(impl.klazz())) {
        return;
    }
    if (HAS_JAVA8_SPLITERATOR_BUG && (LinkedBlockingDeque.class.equals(impl.klazz())) || LinkedBlockingQueue.class.equals(impl.klazz())) {
        // https://bugs.openjdk.java.net/browse/JDK-8171051
        return;
    }
    Collection c = impl.emptyCollection();
    ThreadLocalRandom rnd = ThreadLocalRandom.current();
    int n = rnd.nextInt(6);
    ArrayList copy = new ArrayList();
    for (int i = 0; i < n; i++) {
        Object x = impl.makeElement(i);
        copy.add(x);
        c.add(x);
    }
    ArrayList iterated = new ArrayList();
    ArrayList spliterated = new ArrayList();
    ArrayList removed = new ArrayList();
    Spliterator<?> s = Spliterators.spliterator(c);
    Iterator<?> it = c.iterator();
    if (!(s.hasCharacteristics(Spliterator.CONCURRENT) || s.hasCharacteristics(Spliterator.IMMUTABLE)))
        return;
    for (int i = rnd.nextInt(n + 1); --i >= 0; ) {
        assertTrue(s.tryAdvance(e -> {
        }));
        if (rnd.nextBoolean())
            assertTrue(it.hasNext());
        it.next();
    }
    // TODO: many more removal methods
    if (rnd.nextBoolean()) {
        for (Iterator<?> z = c.iterator(); z.hasNext(); ) {
            Object e = z.next();
            if (rnd.nextBoolean()) {
                try {
                    z.remove();
                } catch (UnsupportedOperationException ok) {
                    return;
                }
                removed.add(e);
            }
        }
    } else {
        Predicate randomlyRemove = e -> {
            if (rnd.nextBoolean()) {
                removed.add(e);
                return true;
            } else
                return false;
        };
        Iterables.removeIf(c, randomlyRemove);
    }
    s.forEachRemaining(spliterated::add);
    while (it.hasNext()) iterated.add(it.next());
    assertTrue(copy.containsAll(iterated));
    assertTrue(copy.containsAll(spliterated));
    assertTrue(copy.containsAll(removed));
    if (s.hasCharacteristics(Spliterator.CONCURRENT)) {
        ArrayList<?> iteratedAndRemoved = new ArrayList<>(iterated);
        ArrayList<?> spliteratedAndRemoved = new ArrayList<>(spliterated);
        iteratedAndRemoved.retainAll(removed);
        spliteratedAndRemoved.retainAll(removed);
        assertTrue(iteratedAndRemoved.size() <= 1);
        assertTrue(spliteratedAndRemoved.size() <= 1);
        if (testImplementationDetails && !(c instanceof java.util.concurrent.ArrayBlockingQueue))
            assertTrue(spliteratedAndRemoved.isEmpty());
    }
}

Example 17 with Spliterator

use of java8.util.Spliterator in project streamsupport by stefan-zobel.

the class ConcatTest method assertLongConcat.

private void assertLongConcat(Stream<Integer> s1, Stream<Integer> s2, boolean parallel, boolean ordered) {
    LongStream result = LongStreams.concat(s1.mapToLong(Integer::longValue), s2.mapToLong(Integer::longValue));
    assertEquals(result.isParallel(), parallel);
    assertConcatContent(result.spliterator(), ordered, StreamSupport.stream(expected).mapToLong(Integer::longValue).spliterator());
}

Example 18 with Spliterator

use of java8.util.Spliterator in project streamsupport by stefan-zobel.

the class SequentialOpTest method testLazy.

@SuppressWarnings("unchecked")
@Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class, groups = { "serialization-hostile" })
public void testLazy(String name, TestData.OfRef<Integer> data) {
    Function<Integer, Integer> id = LambdaTestHelpers.identity();
    AtomicInteger counter = new AtomicInteger();
    Supplier<Stream<Integer>>[] suppliers = new Supplier[] { () -> data.stream(), () -> data.parallelStream() };
    UnaryOperator<Stream<Integer>>[] configs = new UnaryOperator[] { (UnaryOperator<Stream<Integer>>) s -> s.peek(e -> {
        counter.incrementAndGet();
    }), (UnaryOperator<Stream<Integer>>) s -> s.map(id).peek(e -> {
        counter.incrementAndGet();
    }).sequential().map(id), (UnaryOperator<Stream<Integer>>) s -> s.map(id).peek(e -> {
        counter.incrementAndGet();
    }).parallel().map(id), (UnaryOperator<Stream<Integer>>) s -> s.sequential().map(id).peek(e -> {
        counter.incrementAndGet();
    }).map(id), (UnaryOperator<Stream<Integer>>) s -> s.parallel().map(id).peek(e -> {
        counter.incrementAndGet();
    }).map(id) };
    for (int i = 0; i < suppliers.length; i++) {
        setContext("supplierIndex", i);
        Supplier<Stream<Integer>> supp = suppliers[i];
        for (int j = 0; j < configs.length; j++) {
            setContext("configIndex", j);
            UnaryOperator<Stream<Integer>> config = configs[j];
            counter.set(0);
            Stream<Integer> stream = config.apply(supp.get());
            assertEquals(0, counter.get());
            Iterator<Integer> iterator = stream.iterator();
            assertEquals(0, counter.get());
            if (iterator.hasNext())
                iterator.next();
            assertTrue(data.size() == 0 || counter.get() > 0);
            counter.set(0);
            stream = config.apply(supp.get());
            Spliterator<Integer> spliterator = stream.spliterator();
            assertEquals(0, counter.get());
            spliterator.forEachRemaining(e -> {
            });
            assertTrue(data.size() == 0 || counter.get() > 0);
        }
    }
}

Example 19 with Spliterator

use of java8.util.Spliterator in project streamsupport by stefan-zobel.

the class DoublePipeline method forEachWithCancel.

@Override
final boolean forEachWithCancel(Spliterator<Double> spliterator, Sink<Double> sink) {
    Spliterator.OfDouble spl = adapt(spliterator);
    DoubleConsumer adaptedSink = adapt(sink);
    boolean cancelled;
    do {
    } while (!(cancelled = sink.cancellationRequested()) && spl.tryAdvance(adaptedSink));
    return cancelled;
}

Example 20 with Spliterator

use of java8.util.Spliterator in project streamsupport by stefan-zobel.

the class Spliterators method iterator.

// Iterators from Spliterators
/**
 * Creates an {@code Iterator} from a {@code Spliterator}.
 *
 * <p>Traversal of elements should be accomplished through the iterator.
 * The behaviour of traversal is undefined if the spliterator is operated
 * after the iterator is returned.
 *
 * @param <T> Type of elements
 * @param spliterator The spliterator
 * @return An iterator
 * @throws NullPointerException if the given spliterator is {@code null}
 */
public static <T> Iterator<T> iterator(Spliterator<? extends T> spliterator) {
    Objects.requireNonNull(spliterator);
    class Adapter implements Iterator<T>, Consumer<T> {

        boolean valueReady = false;

        T nextElement;

        @Override
        public void accept(T t) {
            valueReady = true;
            nextElement = t;
        }

        @Override
        public boolean hasNext() {
            if (!valueReady)
                spliterator.tryAdvance(this);
            return valueReady;
        }

        @Override
        public T next() {
            if (!valueReady && !hasNext())
                throw new NoSuchElementException();
            else {
                valueReady = false;
                return nextElement;
            }
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException("remove");
        }
    }
    return new Adapter();
}