/*
* Copyright (c) 2012, 2014, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*/
package java.util.stream;
import java.util.
IntSummaryStatistics;
import java.util.
Objects;
import java.util.
OptionalDouble;
import java.util.
OptionalInt;
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.
IntBinaryOperator;
import java.util.function.
IntConsumer;
import java.util.function.
IntFunction;
import java.util.function.
IntPredicate;
import java.util.function.
IntToDoubleFunction;
import java.util.function.
IntToLongFunction;
import java.util.function.
IntUnaryOperator;
import java.util.function.
ObjIntConsumer;
import java.util.function.
Supplier;
/**
* Abstract base class for an intermediate pipeline stage or pipeline source
* stage implementing whose elements are of type {@code int}.
*
* @param <E_IN> type of elements in the upstream source
* @since 1.8
*/
abstract class
IntPipeline<E_IN>
extends
AbstractPipeline<E_IN,
Integer,
IntStream>
implements
IntStream {
/**
* 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
*/
IntPipeline(
Supplier<? extends
Spliterator<
Integer>>
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
*/
IntPipeline(
Spliterator<
Integer>
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 for the new operation
*/
IntPipeline(
AbstractPipeline<?, E_IN, ?>
upstream, int
opFlags) {
super(
upstream,
opFlags);
}
/**
* Adapt a {@code Sink<Integer> to an {@code IntConsumer}, ideally simply
* by casting.
*/
private static
IntConsumer adapt(
Sink<
Integer>
sink) {
if (
sink instanceof
IntConsumer) {
return (
IntConsumer)
sink;
}
else {
if (
Tripwire.
ENABLED)
Tripwire.
trip(
AbstractPipeline.class,
"using IntStream.adapt(Sink<Integer> s)");
return
sink::accept;
}
}
/**
* Adapt a {@code Spliterator<Integer>} to a {@code Spliterator.OfInt}.
*
* @implNote
* The implementation attempts to cast to a Spliterator.OfInt, and throws an
* exception if this cast is not possible.
*/
private static
Spliterator.
OfInt adapt(
Spliterator<
Integer>
s) {
if (
s instanceof
Spliterator.
OfInt) {
return (
Spliterator.
OfInt)
s;
}
else {
if (
Tripwire.
ENABLED)
Tripwire.
trip(
AbstractPipeline.class,
"using IntStream.adapt(Spliterator<Integer> s)");
throw new
UnsupportedOperationException("IntStream.adapt(Spliterator<Integer> s)");
}
}
// Shape-specific methods
@
Override
final
StreamShape getOutputShape() {
return
StreamShape.
INT_VALUE;
}
@
Override
final <P_IN>
Node<
Integer>
evaluateToNode(
PipelineHelper<
Integer>
helper,
Spliterator<P_IN>
spliterator,
boolean
flattenTree,
IntFunction<
Integer[]>
generator) {
return
Nodes.
collectInt(
helper,
spliterator,
flattenTree);
}
@
Override
final <P_IN>
Spliterator<
Integer>
wrap(
PipelineHelper<
Integer>
ph,
Supplier<
Spliterator<P_IN>>
supplier,
boolean
isParallel) {
return new
StreamSpliterators.
IntWrappingSpliterator<>(
ph,
supplier,
isParallel);
}
@
Override
@
SuppressWarnings("unchecked")
final
Spliterator.
OfInt lazySpliterator(
Supplier<? extends
Spliterator<
Integer>>
supplier) {
return new
StreamSpliterators.
DelegatingSpliterator.
OfInt((
Supplier<
Spliterator.
OfInt>)
supplier);
}
@
Override
final void
forEachWithCancel(
Spliterator<
Integer>
spliterator,
Sink<
Integer>
sink) {
Spliterator.
OfInt spl =
adapt(
spliterator);
IntConsumer adaptedSink =
adapt(
sink);
do { } while (!
sink.
cancellationRequested() &&
spl.
tryAdvance(
adaptedSink));
}
@
Override
final
Node.
Builder<
Integer>
makeNodeBuilder(long
exactSizeIfKnown,
IntFunction<
Integer[]>
generator) {
return
Nodes.
intBuilder(
exactSizeIfKnown);
}
// IntStream
@
Override
public final
PrimitiveIterator.
OfInt iterator() {
return
Spliterators.
iterator(
spliterator());
}
@
Override
public final
Spliterator.
OfInt spliterator() {
return
adapt(super.spliterator());
}
// Stateless intermediate ops from IntStream
@
Override
public final
LongStream asLongStream() {
return new
LongPipeline.
StatelessOp<
Integer>(this,
StreamShape.
INT_VALUE,
StreamOpFlag.
NOT_SORTED |
StreamOpFlag.
NOT_DISTINCT) {
@
Override
Sink<
Integer>
opWrapSink(int
flags,
Sink<
Long>
sink) {
return new
Sink.
ChainedInt<
Long>(
sink) {
@
Override
public void
accept(int
t) {
downstream.
accept((long)
t);
}
};
}
};
}
@
Override
public final
DoubleStream asDoubleStream() {
return new
DoublePipeline.
StatelessOp<
Integer>(this,
StreamShape.
INT_VALUE,
StreamOpFlag.
NOT_SORTED |
StreamOpFlag.
NOT_DISTINCT) {
@
Override
Sink<
Integer>
opWrapSink(int
flags,
Sink<
Double>
sink) {
return new
Sink.
ChainedInt<
Double>(
sink) {
@
Override
public void
accept(int
t) {
downstream.
accept((double)
t);
}
};
}
};
}
@
Override
public final
Stream<
Integer>
boxed() {
return
mapToObj(
Integer::valueOf);
}
@
Override
public final
IntStream map(
IntUnaryOperator mapper) {
Objects.
requireNonNull(
mapper);
return new
StatelessOp<
Integer>(this,
StreamShape.
INT_VALUE,
StreamOpFlag.
NOT_SORTED |
StreamOpFlag.
NOT_DISTINCT) {
@
Override
Sink<
Integer>
opWrapSink(int
flags,
Sink<
Integer>
sink) {
return new
Sink.
ChainedInt<
Integer>(
sink) {
@
Override
public void
accept(int
t) {
downstream.
accept(
mapper.
applyAsInt(
t));
}
};
}
};
}
@
Override
public final <U>
Stream<U>
mapToObj(
IntFunction<? extends U>
mapper) {
Objects.
requireNonNull(
mapper);
return new
ReferencePipeline.
StatelessOp<
Integer, U>(this,
StreamShape.
INT_VALUE,
StreamOpFlag.
NOT_SORTED |
StreamOpFlag.
NOT_DISTINCT) {
@
Override
Sink<
Integer>
opWrapSink(int
flags,
Sink<U>
sink) {
return new
Sink.
ChainedInt<U>(
sink) {
@
Override
public void
accept(int
t) {
downstream.
accept(
mapper.
apply(
t));
}
};
}
};
}
@
Override
public final
LongStream mapToLong(
IntToLongFunction mapper) {
Objects.
requireNonNull(
mapper);
return new
LongPipeline.
StatelessOp<
Integer>(this,
StreamShape.
INT_VALUE,
StreamOpFlag.
NOT_SORTED |
StreamOpFlag.
NOT_DISTINCT) {
@
Override
Sink<
Integer>
opWrapSink(int
flags,
Sink<
Long>
sink) {
return new
Sink.
ChainedInt<
Long>(
sink) {
@
Override
public void
accept(int
t) {
downstream.
accept(
mapper.
applyAsLong(
t));
}
};
}
};
}
@
Override
public final
DoubleStream mapToDouble(
IntToDoubleFunction mapper) {
Objects.
requireNonNull(
mapper);
return new
DoublePipeline.
StatelessOp<
Integer>(this,
StreamShape.
INT_VALUE,
StreamOpFlag.
NOT_SORTED |
StreamOpFlag.
NOT_DISTINCT) {
@
Override
Sink<
Integer>
opWrapSink(int
flags,
Sink<
Double>
sink) {
return new
Sink.
ChainedInt<
Double>(
sink) {
@
Override
public void
accept(int
t) {
downstream.
accept(
mapper.
applyAsDouble(
t));
}
};
}
};
}
@
Override
public final
IntStream flatMap(
IntFunction<? extends
IntStream>
mapper) {
return new
StatelessOp<
Integer>(this,
StreamShape.
INT_VALUE,
StreamOpFlag.
NOT_SORTED |
StreamOpFlag.
NOT_DISTINCT |
StreamOpFlag.
NOT_SIZED) {
@
Override
Sink<
Integer>
opWrapSink(int
flags,
Sink<
Integer>
sink) {
return new
Sink.
ChainedInt<
Integer>(
sink) {
@
Override
public void
begin(long
size) {
downstream.
begin(-1);
}
@
Override
public void
accept(int
t) {
try (
IntStream 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
IntStream unordered() {
if (!
isOrdered())
return this;
return new
StatelessOp<
Integer>(this,
StreamShape.
INT_VALUE,
StreamOpFlag.
NOT_ORDERED) {
@
Override
Sink<
Integer>
opWrapSink(int
flags,
Sink<
Integer>
sink) {
return
sink;
}
};
}
@
Override
public final
IntStream filter(
IntPredicate predicate) {
Objects.
requireNonNull(
predicate);
return new
StatelessOp<
Integer>(this,
StreamShape.
INT_VALUE,
StreamOpFlag.
NOT_SIZED) {
@
Override
Sink<
Integer>
opWrapSink(int
flags,
Sink<
Integer>
sink) {
return new
Sink.
ChainedInt<
Integer>(
sink) {
@
Override
public void
begin(long
size) {
downstream.
begin(-1);
}
@
Override
public void
accept(int
t) {
if (
predicate.
test(
t))
downstream.
accept(
t);
}
};
}
};
}
@
Override
public final
IntStream peek(
IntConsumer action) {
Objects.
requireNonNull(
action);
return new
StatelessOp<
Integer>(this,
StreamShape.
INT_VALUE,
0) {
@
Override
Sink<
Integer>
opWrapSink(int
flags,
Sink<
Integer>
sink) {
return new
Sink.
ChainedInt<
Integer>(
sink) {
@
Override
public void
accept(int
t) {
action.
accept(
t);
downstream.
accept(
t);
}
};
}
};
}
// Stateful intermediate ops from IntStream
@
Override
public final
IntStream limit(long
maxSize) {
if (
maxSize < 0)
throw new
IllegalArgumentException(
Long.
toString(
maxSize));
return
SliceOps.
makeInt(this, 0,
maxSize);
}
@
Override
public final
IntStream skip(long
n) {
if (
n < 0)
throw new
IllegalArgumentException(
Long.
toString(
n));
if (
n == 0)
return this;
else
return
SliceOps.
makeInt(this,
n, -1);
}
@
Override
public final
IntStream sorted() {
return
SortedOps.
makeInt(this);
}
@
Override
public final
IntStream distinct() {
// While functional and quick to implement, this approach is not very efficient.
// An efficient version requires an int-specific map/set implementation.
return
boxed().
distinct().
mapToInt(
i ->
i);
}
// Terminal ops from IntStream
@
Override
public void
forEach(
IntConsumer action) {
evaluate(
ForEachOps.
makeInt(
action, false));
}
@
Override
public void
forEachOrdered(
IntConsumer action) {
evaluate(
ForEachOps.
makeInt(
action, true));
}
@
Override
public final int
sum() {
return
reduce(0,
Integer::sum);
}
@
Override
public final
OptionalInt min() {
return
reduce(
Math::min);
}
@
Override
public final
OptionalInt max() {
return
reduce(
Math::max);
}
@
Override
public final long
count() {
return
mapToLong(
e -> 1L).
sum();
}
@
Override
public final
OptionalDouble average() {
long[]
avg =
collect(() -> new long[2],
(
ll,
i) -> {
ll[0]++;
ll[1] +=
i;
},
(
ll,
rr) -> {
ll[0] +=
rr[0];
ll[1] +=
rr[1];
});
return
avg[0] > 0
?
OptionalDouble.
of((double)
avg[1] /
avg[0])
:
OptionalDouble.
empty();
}
@
Override
public final
IntSummaryStatistics summaryStatistics() {
return
collect(
IntSummaryStatistics::new,
IntSummaryStatistics::accept,
IntSummaryStatistics::combine);
}
@
Override
public final int
reduce(int
identity,
IntBinaryOperator op) {
return
evaluate(
ReduceOps.
makeInt(
identity,
op));
}
@
Override
public final
OptionalInt reduce(
IntBinaryOperator op) {
return
evaluate(
ReduceOps.
makeInt(
op));
}
@
Override
public final <R> R
collect(
Supplier<R>
supplier,
ObjIntConsumer<R>
accumulator,
BiConsumer<R, R>
combiner) {
BinaryOperator<R>
operator = (
left,
right) -> {
combiner.
accept(
left,
right);
return
left;
};
return
evaluate(
ReduceOps.
makeInt(
supplier,
accumulator,
operator));
}
@
Override
public final boolean
anyMatch(
IntPredicate predicate) {
return
evaluate(
MatchOps.
makeInt(
predicate,
MatchOps.
MatchKind.
ANY));
}
@
Override
public final boolean
allMatch(
IntPredicate predicate) {
return
evaluate(
MatchOps.
makeInt(
predicate,
MatchOps.
MatchKind.
ALL));
}
@
Override
public final boolean
noneMatch(
IntPredicate predicate) {
return
evaluate(
MatchOps.
makeInt(
predicate,
MatchOps.
MatchKind.
NONE));
}
@
Override
public final
OptionalInt findFirst() {
return
evaluate(
FindOps.
makeInt(true));
}
@
Override
public final
OptionalInt findAny() {
return
evaluate(
FindOps.
makeInt(false));
}
@
Override
public final int[]
toArray() {
return
Nodes.
flattenInt((
Node.
OfInt)
evaluateToArrayNode(
Integer[]::new))
.
asPrimitiveArray();
}
//
/**
* Source stage of an IntStream.
*
* @param <E_IN> type of elements in the upstream source
* @since 1.8
*/
static class
Head<E_IN> extends
IntPipeline<E_IN> {
/**
* Constructor for the source stage of an IntStream.
*
* @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<
Integer>>
source,
int
sourceFlags, boolean
parallel) {
super(
source,
sourceFlags,
parallel);
}
/**
* Constructor for the source stage of an IntStream.
*
* @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<
Integer>
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<
Integer>
sink) {
throw new
UnsupportedOperationException();
}
// Optimized sequential terminal operations for the head of the pipeline
@
Override
public void
forEach(
IntConsumer action) {
if (!
isParallel()) {
adapt(
sourceStageSpliterator()).
forEachRemaining(
action);
}
else {
super.forEach(
action);
}
}
@
Override
public void
forEachOrdered(
IntConsumer action) {
if (!
isParallel()) {
adapt(
sourceStageSpliterator()).
forEachRemaining(
action);
}
else {
super.forEachOrdered(
action);
}
}
}
/**
* Base class for a stateless intermediate stage of an IntStream
*
* @param <E_IN> type of elements in the upstream source
* @since 1.8
*/
abstract static class
StatelessOp<E_IN> extends
IntPipeline<E_IN> {
/**
* Construct a new IntStream 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 an IntStream.
*
* @param <E_IN> type of elements in the upstream source
* @since 1.8
*/
abstract static class
StatefulOp<E_IN> extends
IntPipeline<E_IN> {
/**
* Construct a new IntStream 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<
Integer>
opEvaluateParallel(
PipelineHelper<
Integer>
helper,
Spliterator<P_IN>
spliterator,
IntFunction<
Integer[]>
generator);
}
}