| /* |
| * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| package java.util.stream; |
| |
| import java.util.Comparator; |
| import java.util.Iterator; |
| import java.util.Objects; |
| import java.util.Optional; |
| import java.util.Spliterator; |
| import java.util.Spliterators; |
| import java.util.function.BiConsumer; |
| import java.util.function.BiFunction; |
| import java.util.function.BinaryOperator; |
| import java.util.function.Consumer; |
| import java.util.function.DoubleConsumer; |
| import java.util.function.Function; |
| import java.util.function.IntConsumer; |
| import java.util.function.IntFunction; |
| import java.util.function.LongConsumer; |
| import java.util.function.Predicate; |
| import java.util.function.Supplier; |
| import java.util.function.ToDoubleFunction; |
| import java.util.function.ToIntFunction; |
| import java.util.function.ToLongFunction; |
| |
| /** |
| * Abstract base class for an intermediate pipeline stage or pipeline source |
| * stage implementing whose elements are of type {@code U}. |
| * |
| * @param <P_IN> type of elements in the upstream source |
| * @param <P_OUT> type of elements in produced by this stage |
| * |
| * @since 1.8 |
| */ |
| abstract class ReferencePipeline<P_IN, P_OUT> |
| extends AbstractPipeline<P_IN, P_OUT, Stream<P_OUT>> |
| implements Stream<P_OUT> { |
| |
| /** |
| * Constructor for the head of a stream pipeline. |
| * |
| * @param source {@code Supplier<Spliterator>} describing the stream source |
| * @param sourceFlags the source flags for the stream source, described in |
| * {@link StreamOpFlag} |
| * @param parallel {@code true} if the pipeline is parallel |
| */ |
| ReferencePipeline(Supplier<? extends Spliterator<?>> source, |
| int sourceFlags, boolean parallel) { |
| super(source, sourceFlags, parallel); |
| } |
| |
| /** |
| * Constructor for the head of a stream pipeline. |
| * |
| * @param source {@code Spliterator} describing the stream source |
| * @param sourceFlags The source flags for the stream source, described in |
| * {@link StreamOpFlag} |
| * @param parallel {@code true} if the pipeline is parallel |
| */ |
| ReferencePipeline(Spliterator<?> source, |
| int sourceFlags, boolean parallel) { |
| super(source, sourceFlags, parallel); |
| } |
| |
| /** |
| * Constructor for appending an intermediate operation onto an existing |
| * pipeline. |
| * |
| * @param upstream the upstream element source. |
| */ |
| ReferencePipeline(AbstractPipeline<?, P_IN, ?> upstream, int opFlags) { |
| super(upstream, opFlags); |
| } |
| |
| // Shape-specific methods |
| |
| @Override |
| final StreamShape getOutputShape() { |
| return StreamShape.REFERENCE; |
| } |
| |
| @Override |
| final <P_IN> Node<P_OUT> evaluateToNode(PipelineHelper<P_OUT> helper, |
| Spliterator<P_IN> spliterator, |
| boolean flattenTree, |
| IntFunction<P_OUT[]> generator) { |
| return Nodes.collect(helper, spliterator, flattenTree, generator); |
| } |
| |
| @Override |
| final <P_IN> Spliterator<P_OUT> wrap(PipelineHelper<P_OUT> ph, |
| Supplier<Spliterator<P_IN>> supplier, |
| boolean isParallel) { |
| return new StreamSpliterators.WrappingSpliterator<>(ph, supplier, isParallel); |
| } |
| |
| @Override |
| final Spliterator<P_OUT> lazySpliterator(Supplier<? extends Spliterator<P_OUT>> supplier) { |
| return new StreamSpliterators.DelegatingSpliterator<>(supplier); |
| } |
| |
| @Override |
| final boolean forEachWithCancel(Spliterator<P_OUT> spliterator, Sink<P_OUT> sink) { |
| boolean cancelled; |
| do { } while (!(cancelled = sink.cancellationRequested()) && spliterator.tryAdvance(sink)); |
| return cancelled; |
| } |
| |
| @Override |
| final Node.Builder<P_OUT> makeNodeBuilder(long exactSizeIfKnown, IntFunction<P_OUT[]> generator) { |
| return Nodes.builder(exactSizeIfKnown, generator); |
| } |
| |
| |
| // BaseStream |
| |
| @Override |
| public final Iterator<P_OUT> iterator() { |
| return Spliterators.iterator(spliterator()); |
| } |
| |
| |
| // Stream |
| |
| // Stateless intermediate operations from Stream |
| |
| @Override |
| public Stream<P_OUT> unordered() { |
| if (!isOrdered()) |
| return this; |
| return new StatelessOp<P_OUT, P_OUT>(this, StreamShape.REFERENCE, StreamOpFlag.NOT_ORDERED) { |
| @Override |
| Sink<P_OUT> opWrapSink(int flags, Sink<P_OUT> sink) { |
| return sink; |
| } |
| }; |
| } |
| |
| @Override |
| public final Stream<P_OUT> filter(Predicate<? super P_OUT> predicate) { |
| Objects.requireNonNull(predicate); |
| return new StatelessOp<P_OUT, P_OUT>(this, StreamShape.REFERENCE, |
| StreamOpFlag.NOT_SIZED) { |
| @Override |
| Sink<P_OUT> opWrapSink(int flags, Sink<P_OUT> sink) { |
| return new Sink.ChainedReference<P_OUT, P_OUT>(sink) { |
| @Override |
| public void begin(long size) { |
| downstream.begin(-1); |
| } |
| |
| @Override |
| public void accept(P_OUT u) { |
| if (predicate.test(u)) |
| downstream.accept(u); |
| } |
| }; |
| } |
| }; |
| } |
| |
| @Override |
| @SuppressWarnings("unchecked") |
| public final <R> Stream<R> map(Function<? super P_OUT, ? extends R> mapper) { |
| Objects.requireNonNull(mapper); |
| return new StatelessOp<P_OUT, R>(this, StreamShape.REFERENCE, |
| StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) { |
| @Override |
| Sink<P_OUT> opWrapSink(int flags, Sink<R> sink) { |
| return new Sink.ChainedReference<P_OUT, R>(sink) { |
| @Override |
| public void accept(P_OUT u) { |
| downstream.accept(mapper.apply(u)); |
| } |
| }; |
| } |
| }; |
| } |
| |
| @Override |
| public final IntStream mapToInt(ToIntFunction<? super P_OUT> mapper) { |
| Objects.requireNonNull(mapper); |
| return new IntPipeline.StatelessOp<P_OUT>(this, StreamShape.REFERENCE, |
| StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) { |
| @Override |
| Sink<P_OUT> opWrapSink(int flags, Sink<Integer> sink) { |
| return new Sink.ChainedReference<P_OUT, Integer>(sink) { |
| @Override |
| public void accept(P_OUT u) { |
| downstream.accept(mapper.applyAsInt(u)); |
| } |
| }; |
| } |
| }; |
| } |
| |
| @Override |
| public final LongStream mapToLong(ToLongFunction<? super P_OUT> mapper) { |
| Objects.requireNonNull(mapper); |
| return new LongPipeline.StatelessOp<P_OUT>(this, StreamShape.REFERENCE, |
| StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) { |
| @Override |
| Sink<P_OUT> opWrapSink(int flags, Sink<Long> sink) { |
| return new Sink.ChainedReference<P_OUT, Long>(sink) { |
| @Override |
| public void accept(P_OUT u) { |
| downstream.accept(mapper.applyAsLong(u)); |
| } |
| }; |
| } |
| }; |
| } |
| |
| @Override |
| public final DoubleStream mapToDouble(ToDoubleFunction<? super P_OUT> mapper) { |
| Objects.requireNonNull(mapper); |
| return new DoublePipeline.StatelessOp<P_OUT>(this, StreamShape.REFERENCE, |
| StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) { |
| @Override |
| Sink<P_OUT> opWrapSink(int flags, Sink<Double> sink) { |
| return new Sink.ChainedReference<P_OUT, Double>(sink) { |
| @Override |
| public void accept(P_OUT u) { |
| downstream.accept(mapper.applyAsDouble(u)); |
| } |
| }; |
| } |
| }; |
| } |
| |
| @Override |
| public final <R> Stream<R> flatMap(Function<? super P_OUT, ? extends Stream<? extends R>> mapper) { |
| Objects.requireNonNull(mapper); |
| // We can do better than this, by polling cancellationRequested when stream is infinite |
| return new StatelessOp<P_OUT, R>(this, StreamShape.REFERENCE, |
| StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT | StreamOpFlag.NOT_SIZED) { |
| @Override |
| Sink<P_OUT> opWrapSink(int flags, Sink<R> sink) { |
| return new Sink.ChainedReference<P_OUT, R>(sink) { |
| @Override |
| public void begin(long size) { |
| downstream.begin(-1); |
| } |
| |
| @Override |
| public void accept(P_OUT u) { |
| try (Stream<? extends R> result = mapper.apply(u)) { |
| // We can do better that this too; optimize for depth=0 case and just grab spliterator and forEach it |
| if (result != null) |
| result.sequential().forEach(downstream); |
| } |
| } |
| }; |
| } |
| }; |
| } |
| |
| @Override |
| public final IntStream flatMapToInt(Function<? super P_OUT, ? extends IntStream> mapper) { |
| Objects.requireNonNull(mapper); |
| // We can do better than this, by polling cancellationRequested when stream is infinite |
| return new IntPipeline.StatelessOp<P_OUT>(this, StreamShape.REFERENCE, |
| StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT | StreamOpFlag.NOT_SIZED) { |
| @Override |
| Sink<P_OUT> opWrapSink(int flags, Sink<Integer> sink) { |
| return new Sink.ChainedReference<P_OUT, Integer>(sink) { |
| IntConsumer downstreamAsInt = downstream::accept; |
| @Override |
| public void begin(long size) { |
| downstream.begin(-1); |
| } |
| |
| @Override |
| public void accept(P_OUT u) { |
| try (IntStream result = mapper.apply(u)) { |
| // We can do better that this too; optimize for depth=0 case and just grab spliterator and forEach it |
| if (result != null) |
| result.sequential().forEach(downstreamAsInt); |
| } |
| } |
| }; |
| } |
| }; |
| } |
| |
| @Override |
| public final DoubleStream flatMapToDouble(Function<? super P_OUT, ? extends DoubleStream> mapper) { |
| Objects.requireNonNull(mapper); |
| // We can do better than this, by polling cancellationRequested when stream is infinite |
| return new DoublePipeline.StatelessOp<P_OUT>(this, StreamShape.REFERENCE, |
| StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT | StreamOpFlag.NOT_SIZED) { |
| @Override |
| Sink<P_OUT> opWrapSink(int flags, Sink<Double> sink) { |
| return new Sink.ChainedReference<P_OUT, Double>(sink) { |
| DoubleConsumer downstreamAsDouble = downstream::accept; |
| @Override |
| public void begin(long size) { |
| downstream.begin(-1); |
| } |
| |
| @Override |
| public void accept(P_OUT u) { |
| try (DoubleStream result = mapper.apply(u)) { |
| // We can do better that this too; optimize for depth=0 case and just grab spliterator and forEach it |
| if (result != null) |
| result.sequential().forEach(downstreamAsDouble); |
| } |
| } |
| }; |
| } |
| }; |
| } |
| |
| @Override |
| public final LongStream flatMapToLong(Function<? super P_OUT, ? extends LongStream> mapper) { |
| Objects.requireNonNull(mapper); |
| // We can do better than this, by polling cancellationRequested when stream is infinite |
| return new LongPipeline.StatelessOp<P_OUT>(this, StreamShape.REFERENCE, |
| StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT | StreamOpFlag.NOT_SIZED) { |
| @Override |
| Sink<P_OUT> opWrapSink(int flags, Sink<Long> sink) { |
| return new Sink.ChainedReference<P_OUT, Long>(sink) { |
| LongConsumer downstreamAsLong = downstream::accept; |
| @Override |
| public void begin(long size) { |
| downstream.begin(-1); |
| } |
| |
| @Override |
| public void accept(P_OUT u) { |
| try (LongStream result = mapper.apply(u)) { |
| // We can do better that this too; optimize for depth=0 case and just grab spliterator and forEach it |
| if (result != null) |
| result.sequential().forEach(downstreamAsLong); |
| } |
| } |
| }; |
| } |
| }; |
| } |
| |
| @Override |
| public final Stream<P_OUT> peek(Consumer<? super P_OUT> action) { |
| Objects.requireNonNull(action); |
| return new StatelessOp<P_OUT, P_OUT>(this, StreamShape.REFERENCE, |
| 0) { |
| @Override |
| Sink<P_OUT> opWrapSink(int flags, Sink<P_OUT> sink) { |
| return new Sink.ChainedReference<P_OUT, P_OUT>(sink) { |
| @Override |
| public void accept(P_OUT u) { |
| action.accept(u); |
| downstream.accept(u); |
| } |
| }; |
| } |
| }; |
| } |
| |
| // Stateful intermediate operations from Stream |
| |
| @Override |
| public final Stream<P_OUT> distinct() { |
| return DistinctOps.makeRef(this); |
| } |
| |
| @Override |
| public final Stream<P_OUT> sorted() { |
| return SortedOps.makeRef(this); |
| } |
| |
| @Override |
| public final Stream<P_OUT> sorted(Comparator<? super P_OUT> comparator) { |
| return SortedOps.makeRef(this, comparator); |
| } |
| |
| @Override |
| public final Stream<P_OUT> limit(long maxSize) { |
| if (maxSize < 0) |
| throw new IllegalArgumentException(Long.toString(maxSize)); |
| return SliceOps.makeRef(this, 0, maxSize); |
| } |
| |
| @Override |
| public final Stream<P_OUT> skip(long n) { |
| if (n < 0) |
| throw new IllegalArgumentException(Long.toString(n)); |
| if (n == 0) |
| return this; |
| else |
| return SliceOps.makeRef(this, n, -1); |
| } |
| |
| @Override |
| public final Stream<P_OUT> takeWhile(Predicate<? super P_OUT> predicate) { |
| return WhileOps.makeTakeWhileRef(this, predicate); |
| } |
| |
| @Override |
| public final Stream<P_OUT> dropWhile(Predicate<? super P_OUT> predicate) { |
| return WhileOps.makeDropWhileRef(this, predicate); |
| } |
| |
| // Terminal operations from Stream |
| |
| @Override |
| public void forEach(Consumer<? super P_OUT> action) { |
| evaluate(ForEachOps.makeRef(action, false)); |
| } |
| |
| @Override |
| public void forEachOrdered(Consumer<? super P_OUT> action) { |
| evaluate(ForEachOps.makeRef(action, true)); |
| } |
| |
| @Override |
| @SuppressWarnings("unchecked") |
| public final <A> A[] toArray(IntFunction<A[]> generator) { |
| // Since A has no relation to U (not possible to declare that A is an upper bound of U) |
| // there will be no static type checking. |
| // Therefore use a raw type and assume A == U rather than propagating the separation of A and U |
| // throughout the code-base. |
| // The runtime type of U is never checked for equality with the component type of the runtime type of A[]. |
| // Runtime checking will be performed when an element is stored in A[], thus if A is not a |
| // super type of U an ArrayStoreException will be thrown. |
| @SuppressWarnings("rawtypes") |
| IntFunction rawGenerator = (IntFunction) generator; |
| return (A[]) Nodes.flatten(evaluateToArrayNode(rawGenerator), rawGenerator) |
| .asArray(rawGenerator); |
| } |
| |
| @Override |
| public final Object[] toArray() { |
| return toArray(Object[]::new); |
| } |
| |
| @Override |
| public final boolean anyMatch(Predicate<? super P_OUT> predicate) { |
| return evaluate(MatchOps.makeRef(predicate, MatchOps.MatchKind.ANY)); |
| } |
| |
| @Override |
| public final boolean allMatch(Predicate<? super P_OUT> predicate) { |
| return evaluate(MatchOps.makeRef(predicate, MatchOps.MatchKind.ALL)); |
| } |
| |
| @Override |
| public final boolean noneMatch(Predicate<? super P_OUT> predicate) { |
| return evaluate(MatchOps.makeRef(predicate, MatchOps.MatchKind.NONE)); |
| } |
| |
| @Override |
| public final Optional<P_OUT> findFirst() { |
| return evaluate(FindOps.makeRef(true)); |
| } |
| |
| @Override |
| public final Optional<P_OUT> findAny() { |
| return evaluate(FindOps.makeRef(false)); |
| } |
| |
| @Override |
| public final P_OUT reduce(final P_OUT identity, final BinaryOperator<P_OUT> accumulator) { |
| return evaluate(ReduceOps.makeRef(identity, accumulator, accumulator)); |
| } |
| |
| @Override |
| public final Optional<P_OUT> reduce(BinaryOperator<P_OUT> accumulator) { |
| return evaluate(ReduceOps.makeRef(accumulator)); |
| } |
| |
| @Override |
| public final <R> R reduce(R identity, BiFunction<R, ? super P_OUT, R> accumulator, BinaryOperator<R> combiner) { |
| return evaluate(ReduceOps.makeRef(identity, accumulator, combiner)); |
| } |
| |
| @Override |
| @SuppressWarnings("unchecked") |
| public final <R, A> R collect(Collector<? super P_OUT, A, R> collector) { |
| A container; |
| if (isParallel() |
| && (collector.characteristics().contains(Collector.Characteristics.CONCURRENT)) |
| && (!isOrdered() || collector.characteristics().contains(Collector.Characteristics.UNORDERED))) { |
| container = collector.supplier().get(); |
| BiConsumer<A, ? super P_OUT> accumulator = collector.accumulator(); |
| forEach(u -> accumulator.accept(container, u)); |
| } |
| else { |
| container = evaluate(ReduceOps.makeRef(collector)); |
| } |
| return collector.characteristics().contains(Collector.Characteristics.IDENTITY_FINISH) |
| ? (R) container |
| : collector.finisher().apply(container); |
| } |
| |
| @Override |
| public final <R> R collect(Supplier<R> supplier, |
| BiConsumer<R, ? super P_OUT> accumulator, |
| BiConsumer<R, R> combiner) { |
| return evaluate(ReduceOps.makeRef(supplier, accumulator, combiner)); |
| } |
| |
| @Override |
| public final Optional<P_OUT> max(Comparator<? super P_OUT> comparator) { |
| return reduce(BinaryOperator.maxBy(comparator)); |
| } |
| |
| @Override |
| public final Optional<P_OUT> min(Comparator<? super P_OUT> comparator) { |
| return reduce(BinaryOperator.minBy(comparator)); |
| |
| } |
| |
| @Override |
| public final long count() { |
| return evaluate(ReduceOps.makeRefCounting()); |
| } |
| |
| // |
| |
| /** |
| * Source stage of a ReferencePipeline. |
| * |
| * @param <E_IN> type of elements in the upstream source |
| * @param <E_OUT> type of elements in produced by this stage |
| * @since 1.8 |
| */ |
| static class Head<E_IN, E_OUT> extends ReferencePipeline<E_IN, E_OUT> { |
| /** |
| * Constructor for the source stage of a Stream. |
| * |
| * @param source {@code Supplier<Spliterator>} describing the stream |
| * source |
| * @param sourceFlags the source flags for the stream source, described |
| * in {@link StreamOpFlag} |
| */ |
| Head(Supplier<? extends Spliterator<?>> source, |
| int sourceFlags, boolean parallel) { |
| super(source, sourceFlags, parallel); |
| } |
| |
| /** |
| * Constructor for the source stage of a Stream. |
| * |
| * @param source {@code Spliterator} describing the stream source |
| * @param sourceFlags the source flags for the stream source, described |
| * in {@link StreamOpFlag} |
| */ |
| Head(Spliterator<?> source, |
| int sourceFlags, boolean parallel) { |
| super(source, sourceFlags, parallel); |
| } |
| |
| @Override |
| final boolean opIsStateful() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| final Sink<E_IN> opWrapSink(int flags, Sink<E_OUT> sink) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| // Optimized sequential terminal operations for the head of the pipeline |
| |
| @Override |
| public void forEach(Consumer<? super E_OUT> action) { |
| if (!isParallel()) { |
| sourceStageSpliterator().forEachRemaining(action); |
| } |
| else { |
| super.forEach(action); |
| } |
| } |
| |
| @Override |
| public void forEachOrdered(Consumer<? super E_OUT> action) { |
| if (!isParallel()) { |
| sourceStageSpliterator().forEachRemaining(action); |
| } |
| else { |
| super.forEachOrdered(action); |
| } |
| } |
| } |
| |
| /** |
| * Base class for a stateless intermediate stage of a Stream. |
| * |
| * @param <E_IN> type of elements in the upstream source |
| * @param <E_OUT> type of elements in produced by this stage |
| * @since 1.8 |
| */ |
| abstract static class StatelessOp<E_IN, E_OUT> |
| extends ReferencePipeline<E_IN, E_OUT> { |
| /** |
| * Construct a new Stream by appending a stateless intermediate |
| * operation to an existing stream. |
| * |
| * @param upstream The upstream pipeline stage |
| * @param inputShape The stream shape for the upstream pipeline stage |
| * @param opFlags Operation flags for the new stage |
| */ |
| StatelessOp(AbstractPipeline<?, E_IN, ?> upstream, |
| StreamShape inputShape, |
| int opFlags) { |
| super(upstream, opFlags); |
| assert upstream.getOutputShape() == inputShape; |
| } |
| |
| @Override |
| final boolean opIsStateful() { |
| return false; |
| } |
| } |
| |
| /** |
| * Base class for a stateful intermediate stage of a Stream. |
| * |
| * @param <E_IN> type of elements in the upstream source |
| * @param <E_OUT> type of elements in produced by this stage |
| * @since 1.8 |
| */ |
| abstract static class StatefulOp<E_IN, E_OUT> |
| extends ReferencePipeline<E_IN, E_OUT> { |
| /** |
| * Construct a new Stream by appending a stateful intermediate operation |
| * to an existing stream. |
| * @param upstream The upstream pipeline stage |
| * @param inputShape The stream shape for the upstream pipeline stage |
| * @param opFlags Operation flags for the new stage |
| */ |
| StatefulOp(AbstractPipeline<?, E_IN, ?> upstream, |
| StreamShape inputShape, |
| int opFlags) { |
| super(upstream, opFlags); |
| assert upstream.getOutputShape() == inputShape; |
| } |
| |
| @Override |
| final boolean opIsStateful() { |
| return true; |
| } |
| |
| @Override |
| abstract <P_IN> Node<E_OUT> opEvaluateParallel(PipelineHelper<E_OUT> helper, |
| Spliterator<P_IN> spliterator, |
| IntFunction<E_OUT[]> generator); |
| } |
| } |