/*
* Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
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package java.util.stream;
import java.util.
LongSummaryStatistics;
import java.util.
Objects;
import java.util.
OptionalDouble;
import java.util.
OptionalLong;
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.
IntFunction;
import java.util.function.
LongBinaryOperator;
import java.util.function.
LongConsumer;
import java.util.function.
LongFunction;
import java.util.function.
LongPredicate;
import java.util.function.
LongToDoubleFunction;
import java.util.function.
LongToIntFunction;
import java.util.function.
LongUnaryOperator;
import java.util.function.
ObjLongConsumer;
import java.util.function.
Supplier;
/**
* Abstract base class for an intermediate pipeline stage or pipeline source
* stage implementing whose elements are of type {@code long}.
*
* @param <E_IN> type of elements in the upstream source
* @since 1.8
*/
abstract class
LongPipeline<E_IN>
extends
AbstractPipeline<E_IN,
Long,
LongStream>
implements
LongStream {
/**
* 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
*/
LongPipeline(
Supplier<? extends
Spliterator<
Long>>
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
*/
LongPipeline(
Spliterator<
Long>
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
*/
LongPipeline(
AbstractPipeline<?, E_IN, ?>
upstream, int
opFlags) {
super(
upstream,
opFlags);
}
/**
* Adapt a {@code Sink<Long> to an {@code LongConsumer}, ideally simply
* by casting.
*/
private static
LongConsumer adapt(
Sink<
Long>
sink) {
if (
sink instanceof
LongConsumer) {
return (
LongConsumer)
sink;
} else {
if (
Tripwire.
ENABLED)
Tripwire.
trip(
AbstractPipeline.class,
"using LongStream.adapt(Sink<Long> s)");
return
sink::accept;
}
}
/**
* Adapt a {@code Spliterator<Long>} to a {@code Spliterator.OfLong}.
*
* @implNote
* The implementation attempts to cast to a Spliterator.OfLong, and throws
* an exception if this cast is not possible.
*/
private static
Spliterator.
OfLong adapt(
Spliterator<
Long>
s) {
if (
s instanceof
Spliterator.
OfLong) {
return (
Spliterator.
OfLong)
s;
} else {
if (
Tripwire.
ENABLED)
Tripwire.
trip(
AbstractPipeline.class,
"using LongStream.adapt(Spliterator<Long> s)");
throw new
UnsupportedOperationException("LongStream.adapt(Spliterator<Long> s)");
}
}
// Shape-specific methods
@
Override
final
StreamShape getOutputShape() {
return
StreamShape.
LONG_VALUE;
}
@
Override
final <P_IN>
Node<
Long>
evaluateToNode(
PipelineHelper<
Long>
helper,
Spliterator<P_IN>
spliterator,
boolean
flattenTree,
IntFunction<
Long[]>
generator) {
return
Nodes.
collectLong(
helper,
spliterator,
flattenTree);
}
@
Override
final <P_IN>
Spliterator<
Long>
wrap(
PipelineHelper<
Long>
ph,
Supplier<
Spliterator<P_IN>>
supplier,
boolean
isParallel) {
return new
StreamSpliterators.
LongWrappingSpliterator<>(
ph,
supplier,
isParallel);
}
@
Override
@
SuppressWarnings("unchecked")
final
Spliterator.
OfLong lazySpliterator(
Supplier<? extends
Spliterator<
Long>>
supplier) {
return new
StreamSpliterators.
DelegatingSpliterator.
OfLong((
Supplier<
Spliterator.
OfLong>)
supplier);
}
@
Override
final void
forEachWithCancel(
Spliterator<
Long>
spliterator,
Sink<
Long>
sink) {
Spliterator.
OfLong spl =
adapt(
spliterator);
LongConsumer adaptedSink =
adapt(
sink);
do { } while (!
sink.
cancellationRequested() &&
spl.
tryAdvance(
adaptedSink));
}
@
Override
final
Node.
Builder<
Long>
makeNodeBuilder(long
exactSizeIfKnown,
IntFunction<
Long[]>
generator) {
return
Nodes.
longBuilder(
exactSizeIfKnown);
}
// LongStream
@
Override
public final
PrimitiveIterator.
OfLong iterator() {
return
Spliterators.
iterator(
spliterator());
}
@
Override
public final
Spliterator.
OfLong spliterator() {
return
adapt(super.spliterator());
}
// Stateless intermediate ops from LongStream
@
Override
public final
DoubleStream asDoubleStream() {
return new
DoublePipeline.
StatelessOp<
Long>(this,
StreamShape.
LONG_VALUE,
StreamOpFlag.
NOT_SORTED |
StreamOpFlag.
NOT_DISTINCT) {
@
Override
Sink<
Long>
opWrapSink(int
flags,
Sink<
Double>
sink) {
return new
Sink.
ChainedLong<
Double>(
sink) {
@
Override
public void
accept(long
t) {
downstream.
accept((double)
t);
}
};
}
};
}
@
Override
public final
Stream<
Long>
boxed() {
return
mapToObj(
Long::valueOf);
}
@
Override
public final
LongStream map(
LongUnaryOperator mapper) {
Objects.
requireNonNull(
mapper);
return new
StatelessOp<
Long>(this,
StreamShape.
LONG_VALUE,
StreamOpFlag.
NOT_SORTED |
StreamOpFlag.
NOT_DISTINCT) {
@
Override
Sink<
Long>
opWrapSink(int
flags,
Sink<
Long>
sink) {
return new
Sink.
ChainedLong<
Long>(
sink) {
@
Override
public void
accept(long
t) {
downstream.
accept(
mapper.
applyAsLong(
t));
}
};
}
};
}
@
Override
public final <U>
Stream<U>
mapToObj(
LongFunction<? extends U>
mapper) {
Objects.
requireNonNull(
mapper);
return new
ReferencePipeline.
StatelessOp<
Long, U>(this,
StreamShape.
LONG_VALUE,
StreamOpFlag.
NOT_SORTED |
StreamOpFlag.
NOT_DISTINCT) {
@
Override
Sink<
Long>
opWrapSink(int
flags,
Sink<U>
sink) {
return new
Sink.
ChainedLong<U>(
sink) {
@
Override
public void
accept(long
t) {
downstream.
accept(
mapper.
apply(
t));
}
};
}
};
}
@
Override
public final
IntStream mapToInt(
LongToIntFunction mapper) {
Objects.
requireNonNull(
mapper);
return new
IntPipeline.
StatelessOp<
Long>(this,
StreamShape.
LONG_VALUE,
StreamOpFlag.
NOT_SORTED |
StreamOpFlag.
NOT_DISTINCT) {
@
Override
Sink<
Long>
opWrapSink(int
flags,
Sink<
Integer>
sink) {
return new
Sink.
ChainedLong<
Integer>(
sink) {
@
Override
public void
accept(long
t) {
downstream.
accept(
mapper.
applyAsInt(
t));
}
};
}
};
}
@
Override
public final
DoubleStream mapToDouble(
LongToDoubleFunction mapper) {
Objects.
requireNonNull(
mapper);
return new
DoublePipeline.
StatelessOp<
Long>(this,
StreamShape.
LONG_VALUE,
StreamOpFlag.
NOT_SORTED |
StreamOpFlag.
NOT_DISTINCT) {
@
Override
Sink<
Long>
opWrapSink(int
flags,
Sink<
Double>
sink) {
return new
Sink.
ChainedLong<
Double>(
sink) {
@
Override
public void
accept(long
t) {
downstream.
accept(
mapper.
applyAsDouble(
t));
}
};
}
};
}
@
Override
public final
LongStream flatMap(
LongFunction<? extends
LongStream>
mapper) {
return new
StatelessOp<
Long>(this,
StreamShape.
LONG_VALUE,
StreamOpFlag.
NOT_SORTED |
StreamOpFlag.
NOT_DISTINCT |
StreamOpFlag.
NOT_SIZED) {
@
Override
Sink<
Long>
opWrapSink(int
flags,
Sink<
Long>
sink) {
return new
Sink.
ChainedLong<
Long>(
sink) {
@
Override
public void
begin(long
size) {
downstream.
begin(-1);
}
@
Override
public void
accept(long
t) {
try (
LongStream 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
LongStream unordered() {
if (!
isOrdered())
return this;
return new
StatelessOp<
Long>(this,
StreamShape.
LONG_VALUE,
StreamOpFlag.
NOT_ORDERED) {
@
Override
Sink<
Long>
opWrapSink(int
flags,
Sink<
Long>
sink) {
return
sink;
}
};
}
@
Override
public final
LongStream filter(
LongPredicate predicate) {
Objects.
requireNonNull(
predicate);
return new
StatelessOp<
Long>(this,
StreamShape.
LONG_VALUE,
StreamOpFlag.
NOT_SIZED) {
@
Override
Sink<
Long>
opWrapSink(int
flags,
Sink<
Long>
sink) {
return new
Sink.
ChainedLong<
Long>(
sink) {
@
Override
public void
begin(long
size) {
downstream.
begin(-1);
}
@
Override
public void
accept(long
t) {
if (
predicate.
test(
t))
downstream.
accept(
t);
}
};
}
};
}
@
Override
public final
LongStream peek(
LongConsumer action) {
Objects.
requireNonNull(
action);
return new
StatelessOp<
Long>(this,
StreamShape.
LONG_VALUE,
0) {
@
Override
Sink<
Long>
opWrapSink(int
flags,
Sink<
Long>
sink) {
return new
Sink.
ChainedLong<
Long>(
sink) {
@
Override
public void
accept(long
t) {
action.
accept(
t);
downstream.
accept(
t);
}
};
}
};
}
// Stateful intermediate ops from LongStream
@
Override
public final
LongStream limit(long
maxSize) {
if (
maxSize < 0)
throw new
IllegalArgumentException(
Long.
toString(
maxSize));
return
SliceOps.
makeLong(this, 0,
maxSize);
}
@
Override
public final
LongStream skip(long
n) {
if (
n < 0)
throw new
IllegalArgumentException(
Long.
toString(
n));
if (
n == 0)
return this;
else
return
SliceOps.
makeLong(this,
n, -1);
}
@
Override
public final
LongStream sorted() {
return
SortedOps.
makeLong(this);
}
@
Override
public final
LongStream distinct() {
// While functional and quick to implement, this approach is not very efficient.
// An efficient version requires a long-specific map/set implementation.
return
boxed().
distinct().
mapToLong(
i -> (long)
i);
}
// Terminal ops from LongStream
@
Override
public void
forEach(
LongConsumer action) {
evaluate(
ForEachOps.
makeLong(
action, false));
}
@
Override
public void
forEachOrdered(
LongConsumer action) {
evaluate(
ForEachOps.
makeLong(
action, true));
}
@
Override
public final long
sum() {
// use better algorithm to compensate for intermediate overflow?
return
reduce(0,
Long::sum);
}
@
Override
public final
OptionalLong min() {
return
reduce(
Math::min);
}
@
Override
public final
OptionalLong max() {
return
reduce(
Math::max);
}
@
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 long
count() {
return
map(
e -> 1L).
sum();
}
@
Override
public final
LongSummaryStatistics summaryStatistics() {
return
collect(
LongSummaryStatistics::new,
LongSummaryStatistics::accept,
LongSummaryStatistics::combine);
}
@
Override
public final long
reduce(long
identity,
LongBinaryOperator op) {
return
evaluate(
ReduceOps.
makeLong(
identity,
op));
}
@
Override
public final
OptionalLong reduce(
LongBinaryOperator op) {
return
evaluate(
ReduceOps.
makeLong(
op));
}
@
Override
public final <R> R
collect(
Supplier<R>
supplier,
ObjLongConsumer<R>
accumulator,
BiConsumer<R, R>
combiner) {
BinaryOperator<R>
operator = (
left,
right) -> {
combiner.
accept(
left,
right);
return
left;
};
return
evaluate(
ReduceOps.
makeLong(
supplier,
accumulator,
operator));
}
@
Override
public final boolean
anyMatch(
LongPredicate predicate) {
return
evaluate(
MatchOps.
makeLong(
predicate,
MatchOps.
MatchKind.
ANY));
}
@
Override
public final boolean
allMatch(
LongPredicate predicate) {
return
evaluate(
MatchOps.
makeLong(
predicate,
MatchOps.
MatchKind.
ALL));
}
@
Override
public final boolean
noneMatch(
LongPredicate predicate) {
return
evaluate(
MatchOps.
makeLong(
predicate,
MatchOps.
MatchKind.
NONE));
}
@
Override
public final
OptionalLong findFirst() {
return
evaluate(
FindOps.
makeLong(true));
}
@
Override
public final
OptionalLong findAny() {
return
evaluate(
FindOps.
makeLong(false));
}
@
Override
public final long[]
toArray() {
return
Nodes.
flattenLong((
Node.
OfLong)
evaluateToArrayNode(
Long[]::new))
.
asPrimitiveArray();
}
//
/**
* Source stage of a LongPipeline.
*
* @param <E_IN> type of elements in the upstream source
* @since 1.8
*/
static class
Head<E_IN> extends
LongPipeline<E_IN> {
/**
* Constructor for the source stage of a LongStream.
*
* @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<
Long>>
source,
int
sourceFlags, boolean
parallel) {
super(
source,
sourceFlags,
parallel);
}
/**
* Constructor for the source stage of a LongStream.
*
* @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<
Long>
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<
Long>
sink) {
throw new
UnsupportedOperationException();
}
// Optimized sequential terminal operations for the head of the pipeline
@
Override
public void
forEach(
LongConsumer action) {
if (!
isParallel()) {
adapt(
sourceStageSpliterator()).
forEachRemaining(
action);
} else {
super.forEach(
action);
}
}
@
Override
public void
forEachOrdered(
LongConsumer action) {
if (!
isParallel()) {
adapt(
sourceStageSpliterator()).
forEachRemaining(
action);
} else {
super.forEachOrdered(
action);
}
}
}
/** Base class for a stateless intermediate stage of a LongStream.
*
* @param <E_IN> type of elements in the upstream source
* @since 1.8
*/
abstract static class
StatelessOp<E_IN> extends
LongPipeline<E_IN> {
/**
* Construct a new LongStream 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 LongStream.
*
* @param <E_IN> type of elements in the upstream source
* @since 1.8
*/
abstract static class
StatefulOp<E_IN> extends
LongPipeline<E_IN> {
/**
* Construct a new LongStream 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<
Long>
opEvaluateParallel(
PipelineHelper<
Long>
helper,
Spliterator<P_IN>
spliterator,
IntFunction<
Long[]>
generator);
}
}