--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.base/share/classes/java/util/stream/DoublePipeline.java Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,641 @@
+/*
+ * Copyright (c) 2013, 2014, 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.DoubleSummaryStatistics;
+import java.util.Objects;
+import java.util.OptionalDouble;
+import java.util.PrimitiveIterator;
+import java.util.Spliterator;
+import java.util.Spliterators;
+import java.util.function.BiConsumer;
+import java.util.function.BinaryOperator;
+import java.util.function.DoubleBinaryOperator;
+import java.util.function.DoubleConsumer;
+import java.util.function.DoubleFunction;
+import java.util.function.DoublePredicate;
+import java.util.function.DoubleToIntFunction;
+import java.util.function.DoubleToLongFunction;
+import java.util.function.DoubleUnaryOperator;
+import java.util.function.IntFunction;
+import java.util.function.ObjDoubleConsumer;
+import java.util.function.Supplier;
+
+/**
+ * Abstract base class for an intermediate pipeline stage or pipeline source
+ * stage implementing whose elements are of type {@code double}.
+ *
+ * @param <E_IN> type of elements in the upstream source
+ *
+ * @since 1.8
+ */
+abstract class DoublePipeline<E_IN>
+ extends AbstractPipeline<E_IN, Double, DoubleStream>
+ implements DoubleStream {
+
+ /**
+ * 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}
+ */
+ DoublePipeline(Supplier<? extends Spliterator<Double>> 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}
+ */
+ DoublePipeline(Spliterator<Double> 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.
+ * @param opFlags the operation flags
+ */
+ DoublePipeline(AbstractPipeline<?, E_IN, ?> upstream, int opFlags) {
+ super(upstream, opFlags);
+ }
+
+ /**
+ * Adapt a {@code Sink<Double> to a {@code DoubleConsumer}, ideally simply
+ * by casting.
+ */
+ private static DoubleConsumer adapt(Sink<Double> sink) {
+ if (sink instanceof DoubleConsumer) {
+ return (DoubleConsumer) sink;
+ } else {
+ if (Tripwire.ENABLED)
+ Tripwire.trip(AbstractPipeline.class,
+ "using DoubleStream.adapt(Sink<Double> s)");
+ return sink::accept;
+ }
+ }
+
+ /**
+ * Adapt a {@code Spliterator<Double>} to a {@code Spliterator.OfDouble}.
+ *
+ * @implNote
+ * The implementation attempts to cast to a Spliterator.OfDouble, and throws
+ * an exception if this cast is not possible.
+ */
+ private static Spliterator.OfDouble adapt(Spliterator<Double> s) {
+ if (s instanceof Spliterator.OfDouble) {
+ return (Spliterator.OfDouble) s;
+ } else {
+ if (Tripwire.ENABLED)
+ Tripwire.trip(AbstractPipeline.class,
+ "using DoubleStream.adapt(Spliterator<Double> s)");
+ throw new UnsupportedOperationException("DoubleStream.adapt(Spliterator<Double> s)");
+ }
+ }
+
+
+ // Shape-specific methods
+
+ @Override
+ final StreamShape getOutputShape() {
+ return StreamShape.DOUBLE_VALUE;
+ }
+
+ @Override
+ final <P_IN> Node<Double> evaluateToNode(PipelineHelper<Double> helper,
+ Spliterator<P_IN> spliterator,
+ boolean flattenTree,
+ IntFunction<Double[]> generator) {
+ return Nodes.collectDouble(helper, spliterator, flattenTree);
+ }
+
+ @Override
+ final <P_IN> Spliterator<Double> wrap(PipelineHelper<Double> ph,
+ Supplier<Spliterator<P_IN>> supplier,
+ boolean isParallel) {
+ return new StreamSpliterators.DoubleWrappingSpliterator<>(ph, supplier, isParallel);
+ }
+
+ @Override
+ @SuppressWarnings("unchecked")
+ final Spliterator.OfDouble lazySpliterator(Supplier<? extends Spliterator<Double>> supplier) {
+ return new StreamSpliterators.DelegatingSpliterator.OfDouble((Supplier<Spliterator.OfDouble>) supplier);
+ }
+
+ @Override
+ final void forEachWithCancel(Spliterator<Double> spliterator, Sink<Double> sink) {
+ Spliterator.OfDouble spl = adapt(spliterator);
+ DoubleConsumer adaptedSink = adapt(sink);
+ do { } while (!sink.cancellationRequested() && spl.tryAdvance(adaptedSink));
+ }
+
+ @Override
+ final Node.Builder<Double> makeNodeBuilder(long exactSizeIfKnown, IntFunction<Double[]> generator) {
+ return Nodes.doubleBuilder(exactSizeIfKnown);
+ }
+
+
+ // DoubleStream
+
+ @Override
+ public final PrimitiveIterator.OfDouble iterator() {
+ return Spliterators.iterator(spliterator());
+ }
+
+ @Override
+ public final Spliterator.OfDouble spliterator() {
+ return adapt(super.spliterator());
+ }
+
+ // Stateless intermediate ops from DoubleStream
+
+ @Override
+ public final Stream<Double> boxed() {
+ return mapToObj(Double::valueOf);
+ }
+
+ @Override
+ public final DoubleStream map(DoubleUnaryOperator mapper) {
+ Objects.requireNonNull(mapper);
+ return new StatelessOp<Double>(this, StreamShape.DOUBLE_VALUE,
+ StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) {
+ @Override
+ Sink<Double> opWrapSink(int flags, Sink<Double> sink) {
+ return new Sink.ChainedDouble<Double>(sink) {
+ @Override
+ public void accept(double t) {
+ downstream.accept(mapper.applyAsDouble(t));
+ }
+ };
+ }
+ };
+ }
+
+ @Override
+ public final <U> Stream<U> mapToObj(DoubleFunction<? extends U> mapper) {
+ Objects.requireNonNull(mapper);
+ return new ReferencePipeline.StatelessOp<Double, U>(this, StreamShape.DOUBLE_VALUE,
+ StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) {
+ @Override
+ Sink<Double> opWrapSink(int flags, Sink<U> sink) {
+ return new Sink.ChainedDouble<U>(sink) {
+ @Override
+ public void accept(double t) {
+ downstream.accept(mapper.apply(t));
+ }
+ };
+ }
+ };
+ }
+
+ @Override
+ public final IntStream mapToInt(DoubleToIntFunction mapper) {
+ Objects.requireNonNull(mapper);
+ return new IntPipeline.StatelessOp<Double>(this, StreamShape.DOUBLE_VALUE,
+ StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) {
+ @Override
+ Sink<Double> opWrapSink(int flags, Sink<Integer> sink) {
+ return new Sink.ChainedDouble<Integer>(sink) {
+ @Override
+ public void accept(double t) {
+ downstream.accept(mapper.applyAsInt(t));
+ }
+ };
+ }
+ };
+ }
+
+ @Override
+ public final LongStream mapToLong(DoubleToLongFunction mapper) {
+ Objects.requireNonNull(mapper);
+ return new LongPipeline.StatelessOp<Double>(this, StreamShape.DOUBLE_VALUE,
+ StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) {
+ @Override
+ Sink<Double> opWrapSink(int flags, Sink<Long> sink) {
+ return new Sink.ChainedDouble<Long>(sink) {
+ @Override
+ public void accept(double t) {
+ downstream.accept(mapper.applyAsLong(t));
+ }
+ };
+ }
+ };
+ }
+
+ @Override
+ public final DoubleStream flatMap(DoubleFunction<? extends DoubleStream> mapper) {
+ Objects.requireNonNull(mapper);
+ return new StatelessOp<Double>(this, StreamShape.DOUBLE_VALUE,
+ StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT | StreamOpFlag.NOT_SIZED) {
+ @Override
+ Sink<Double> opWrapSink(int flags, Sink<Double> sink) {
+ return new Sink.ChainedDouble<Double>(sink) {
+ @Override
+ public void begin(long size) {
+ downstream.begin(-1);
+ }
+
+ @Override
+ public void accept(double t) {
+ try (DoubleStream result = mapper.apply(t)) {
+ // 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(i -> downstream.accept(i));
+ }
+ }
+ };
+ }
+ };
+ }
+
+ @Override
+ public DoubleStream unordered() {
+ if (!isOrdered())
+ return this;
+ return new StatelessOp<Double>(this, StreamShape.DOUBLE_VALUE, StreamOpFlag.NOT_ORDERED) {
+ @Override
+ Sink<Double> opWrapSink(int flags, Sink<Double> sink) {
+ return sink;
+ }
+ };
+ }
+
+ @Override
+ public final DoubleStream filter(DoublePredicate predicate) {
+ Objects.requireNonNull(predicate);
+ return new StatelessOp<Double>(this, StreamShape.DOUBLE_VALUE,
+ StreamOpFlag.NOT_SIZED) {
+ @Override
+ Sink<Double> opWrapSink(int flags, Sink<Double> sink) {
+ return new Sink.ChainedDouble<Double>(sink) {
+ @Override
+ public void begin(long size) {
+ downstream.begin(-1);
+ }
+
+ @Override
+ public void accept(double t) {
+ if (predicate.test(t))
+ downstream.accept(t);
+ }
+ };
+ }
+ };
+ }
+
+ @Override
+ public final DoubleStream peek(DoubleConsumer action) {
+ Objects.requireNonNull(action);
+ return new StatelessOp<Double>(this, StreamShape.DOUBLE_VALUE,
+ 0) {
+ @Override
+ Sink<Double> opWrapSink(int flags, Sink<Double> sink) {
+ return new Sink.ChainedDouble<Double>(sink) {
+ @Override
+ public void accept(double t) {
+ action.accept(t);
+ downstream.accept(t);
+ }
+ };
+ }
+ };
+ }
+
+ // Stateful intermediate ops from DoubleStream
+
+ @Override
+ public final DoubleStream limit(long maxSize) {
+ if (maxSize < 0)
+ throw new IllegalArgumentException(Long.toString(maxSize));
+ return SliceOps.makeDouble(this, (long) 0, maxSize);
+ }
+
+ @Override
+ public final DoubleStream skip(long n) {
+ if (n < 0)
+ throw new IllegalArgumentException(Long.toString(n));
+ if (n == 0)
+ return this;
+ else {
+ long limit = -1;
+ return SliceOps.makeDouble(this, n, limit);
+ }
+ }
+
+ @Override
+ public final DoubleStream sorted() {
+ return SortedOps.makeDouble(this);
+ }
+
+ @Override
+ public final DoubleStream distinct() {
+ // While functional and quick to implement, this approach is not very efficient.
+ // An efficient version requires a double-specific map/set implementation.
+ return boxed().distinct().mapToDouble(i -> (double) i);
+ }
+
+ // Terminal ops from DoubleStream
+
+ @Override
+ public void forEach(DoubleConsumer consumer) {
+ evaluate(ForEachOps.makeDouble(consumer, false));
+ }
+
+ @Override
+ public void forEachOrdered(DoubleConsumer consumer) {
+ evaluate(ForEachOps.makeDouble(consumer, true));
+ }
+
+ @Override
+ public final double sum() {
+ /*
+ * In the arrays allocated for the collect operation, index 0
+ * holds the high-order bits of the running sum, index 1 holds
+ * the low-order bits of the sum computed via compensated
+ * summation, and index 2 holds the simple sum used to compute
+ * the proper result if the stream contains infinite values of
+ * the same sign.
+ */
+ double[] summation = collect(() -> new double[3],
+ (ll, d) -> {
+ Collectors.sumWithCompensation(ll, d);
+ ll[2] += d;
+ },
+ (ll, rr) -> {
+ Collectors.sumWithCompensation(ll, rr[0]);
+ Collectors.sumWithCompensation(ll, rr[1]);
+ ll[2] += rr[2];
+ });
+
+ return Collectors.computeFinalSum(summation);
+ }
+
+ @Override
+ public final OptionalDouble min() {
+ return reduce(Math::min);
+ }
+
+ @Override
+ public final OptionalDouble max() {
+ return reduce(Math::max);
+ }
+
+ /**
+ * {@inheritDoc}
+ *
+ * @implNote The {@code double} format can represent all
+ * consecutive integers in the range -2<sup>53</sup> to
+ * 2<sup>53</sup>. If the pipeline has more than 2<sup>53</sup>
+ * values, the divisor in the average computation will saturate at
+ * 2<sup>53</sup>, leading to additional numerical errors.
+ */
+ @Override
+ public final OptionalDouble average() {
+ /*
+ * In the arrays allocated for the collect operation, index 0
+ * holds the high-order bits of the running sum, index 1 holds
+ * the low-order bits of the sum computed via compensated
+ * summation, index 2 holds the number of values seen, index 3
+ * holds the simple sum.
+ */
+ double[] avg = collect(() -> new double[4],
+ (ll, d) -> {
+ ll[2]++;
+ Collectors.sumWithCompensation(ll, d);
+ ll[3] += d;
+ },
+ (ll, rr) -> {
+ Collectors.sumWithCompensation(ll, rr[0]);
+ Collectors.sumWithCompensation(ll, rr[1]);
+ ll[2] += rr[2];
+ ll[3] += rr[3];
+ });
+ return avg[2] > 0
+ ? OptionalDouble.of(Collectors.computeFinalSum(avg) / avg[2])
+ : OptionalDouble.empty();
+ }
+
+ @Override
+ public final long count() {
+ return mapToLong(e -> 1L).sum();
+ }
+
+ @Override
+ public final DoubleSummaryStatistics summaryStatistics() {
+ return collect(DoubleSummaryStatistics::new, DoubleSummaryStatistics::accept,
+ DoubleSummaryStatistics::combine);
+ }
+
+ @Override
+ public final double reduce(double identity, DoubleBinaryOperator op) {
+ return evaluate(ReduceOps.makeDouble(identity, op));
+ }
+
+ @Override
+ public final OptionalDouble reduce(DoubleBinaryOperator op) {
+ return evaluate(ReduceOps.makeDouble(op));
+ }
+
+ @Override
+ public final <R> R collect(Supplier<R> supplier,
+ ObjDoubleConsumer<R> accumulator,
+ BiConsumer<R, R> combiner) {
+ Objects.requireNonNull(combiner);
+ BinaryOperator<R> operator = (left, right) -> {
+ combiner.accept(left, right);
+ return left;
+ };
+ return evaluate(ReduceOps.makeDouble(supplier, accumulator, operator));
+ }
+
+ @Override
+ public final boolean anyMatch(DoublePredicate predicate) {
+ return evaluate(MatchOps.makeDouble(predicate, MatchOps.MatchKind.ANY));
+ }
+
+ @Override
+ public final boolean allMatch(DoublePredicate predicate) {
+ return evaluate(MatchOps.makeDouble(predicate, MatchOps.MatchKind.ALL));
+ }
+
+ @Override
+ public final boolean noneMatch(DoublePredicate predicate) {
+ return evaluate(MatchOps.makeDouble(predicate, MatchOps.MatchKind.NONE));
+ }
+
+ @Override
+ public final OptionalDouble findFirst() {
+ return evaluate(FindOps.makeDouble(true));
+ }
+
+ @Override
+ public final OptionalDouble findAny() {
+ return evaluate(FindOps.makeDouble(false));
+ }
+
+ @Override
+ public final double[] toArray() {
+ return Nodes.flattenDouble((Node.OfDouble) evaluateToArrayNode(Double[]::new))
+ .asPrimitiveArray();
+ }
+
+ //
+
+ /**
+ * Source stage of a DoubleStream
+ *
+ * @param <E_IN> type of elements in the upstream source
+ */
+ static class Head<E_IN> extends DoublePipeline<E_IN> {
+ /**
+ * Constructor for the source stage of a DoubleStream.
+ *
+ * @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
+ */
+ Head(Supplier<? extends Spliterator<Double>> source,
+ int sourceFlags, boolean parallel) {
+ super(source, sourceFlags, parallel);
+ }
+
+ /**
+ * Constructor for the source stage of a DoubleStream.
+ *
+ * @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
+ */
+ Head(Spliterator<Double> 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<Double> sink) {
+ throw new UnsupportedOperationException();
+ }
+
+ // Optimized sequential terminal operations for the head of the pipeline
+
+ @Override
+ public void forEach(DoubleConsumer consumer) {
+ if (!isParallel()) {
+ adapt(sourceStageSpliterator()).forEachRemaining(consumer);
+ }
+ else {
+ super.forEach(consumer);
+ }
+ }
+
+ @Override
+ public void forEachOrdered(DoubleConsumer consumer) {
+ if (!isParallel()) {
+ adapt(sourceStageSpliterator()).forEachRemaining(consumer);
+ }
+ else {
+ super.forEachOrdered(consumer);
+ }
+ }
+
+ }
+
+ /**
+ * Base class for a stateless intermediate stage of a DoubleStream.
+ *
+ * @param <E_IN> type of elements in the upstream source
+ * @since 1.8
+ */
+ abstract static class StatelessOp<E_IN> extends DoublePipeline<E_IN> {
+ /**
+ * Construct a new DoubleStream 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 DoubleStream.
+ *
+ * @param <E_IN> type of elements in the upstream source
+ * @since 1.8
+ */
+ abstract static class StatefulOp<E_IN> extends DoublePipeline<E_IN> {
+ /**
+ * Construct a new DoubleStream 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<Double> opEvaluateParallel(PipelineHelper<Double> helper,
+ Spliterator<P_IN> spliterator,
+ IntFunction<Double[]> generator);
+ }
+}