/*
* Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* 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
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*
* 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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
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*
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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) {
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 substream(long startingOffset) {
if (startingOffset < 0)
throw new IllegalArgumentException(Long.toString(startingOffset));
if (startingOffset == 0)
return this;
else {
long limit = -1;
return SliceOps.makeDouble(this, startingOffset, limit);
}
}
@Override
public final DoubleStream substream(long startingOffset, long endingOffset) {
if (startingOffset < 0 || endingOffset < startingOffset)
throw new IllegalArgumentException(String.format("substream(%d, %d)", startingOffset, endingOffset));
return SliceOps.makeDouble(this, startingOffset, endingOffset - startingOffset);
}
@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() {
// TODO: better algorithm to compensate for errors
return reduce(0.0, Double::sum);
}
@Override
public final OptionalDouble min() {
return reduce(Math::min);
}
@Override
public final OptionalDouble max() {
return reduce(Math::max);
}
@Override
public final OptionalDouble average() {
double[] avg = collect(() -> new double[2],
(ll, i) -> {
ll[0]++;
ll[1] += i;
},
(ll, rr) -> {
ll[0] += rr[0];
ll[1] += rr[1];
});
return avg[0] > 0
? OptionalDouble.of(avg[1] / avg[0])
: OptionalDouble.empty();
}
@Override
public final long count() {
return mapToObj(e -> null).mapToInt(e -> 1).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) {
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);
}
}