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8265029: Preserve SIZED characteristics on slice operations (skip, limit)

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Reviewed-by: psandoz
This commit is contained in:
Tagir F. Valeev 2021-05-28 01:56:38 +00:00
parent 95b1fa7a88
commit 0c9daa7ed5
12 changed files with 704 additions and 89 deletions
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75
src/java.base/share/classes/java/util/stream/SliceOps.java
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@ -1,5 +1,5 @@
/*
* Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012, 2021, 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
@ -50,7 +50,7 @@ final class SliceOps {
* @return the sliced size
*/
private static long calcSize(long size, long skip, long limit) {
return size >= 0 ? Math.max(-1, Math.min(size - skip, limit)) : -1;
return size >= 0 ? Math.max(0, Math.min(size - skip, limit)) : -1;
}
/**
@ -72,28 +72,23 @@ final class SliceOps {
* spliterator type. Requires that the underlying Spliterator
* be SUBSIZED.
*/
@SuppressWarnings("unchecked")
private static <P_IN> Spliterator<P_IN> sliceSpliterator(StreamShape shape,
Spliterator<P_IN> s,
long skip, long limit) {
assert s.hasCharacteristics(Spliterator.SUBSIZED);
long sliceFence = calcSliceFence(skip, limit);
switch (shape) {
case REFERENCE:
return new StreamSpliterators
.SliceSpliterator.OfRef<>(s, skip, sliceFence);
case INT_VALUE:
return (Spliterator<P_IN>) new StreamSpliterators
.SliceSpliterator.OfInt((Spliterator.OfInt) s, skip, sliceFence);
case LONG_VALUE:
return (Spliterator<P_IN>) new StreamSpliterators
.SliceSpliterator.OfLong((Spliterator.OfLong) s, skip, sliceFence);
case DOUBLE_VALUE:
return (Spliterator<P_IN>) new StreamSpliterators
.SliceSpliterator.OfDouble((Spliterator.OfDouble) s, skip, sliceFence);
default:
throw new IllegalStateException("Unknown shape " + shape);
}
@SuppressWarnings("unchecked")
Spliterator<P_IN> sliceSpliterator = (Spliterator<P_IN>) switch (shape) {
case REFERENCE
-> new StreamSpliterators.SliceSpliterator.OfRef<>(s, skip, sliceFence);
case INT_VALUE
-> new StreamSpliterators.SliceSpliterator.OfInt((Spliterator.OfInt) s, skip, sliceFence);
case LONG_VALUE
-> new StreamSpliterators.SliceSpliterator.OfLong((Spliterator.OfLong) s, skip, sliceFence);
case DOUBLE_VALUE
-> new StreamSpliterators.SliceSpliterator.OfDouble((Spliterator.OfDouble) s, skip, sliceFence);
};
return sliceSpliterator;
}
/**
@ -110,9 +105,15 @@ final class SliceOps {
long skip, long limit) {
if (skip < 0)
throw new IllegalArgumentException("Skip must be non-negative: " + skip);
long normalizedLimit = limit >= 0 ? limit : Long.MAX_VALUE;
return new ReferencePipeline.StatefulOp<T, T>(upstream, StreamShape.REFERENCE,
flags(limit)) {
@Override
long exactOutputSize(long previousSize) {
return calcSize(previousSize, skip, normalizedLimit);
}
Spliterator<T> unorderedSkipLimitSpliterator(Spliterator<T> s,
long skip, long limit, long sizeIfKnown) {
if (skip <= sizeIfKnown) {
@ -182,9 +183,9 @@ final class SliceOps {
@Override
Sink<T> opWrapSink(int flags, Sink<T> sink) {
return new Sink.ChainedReference<T, T>(sink) {
return new Sink.ChainedReference<>(sink) {
long n = skip;
long m = limit >= 0 ? limit : Long.MAX_VALUE;
long m = normalizedLimit;
@Override
public void begin(long size) {
@ -226,9 +227,15 @@ final class SliceOps {
long skip, long limit) {
if (skip < 0)
throw new IllegalArgumentException("Skip must be non-negative: " + skip);
long normalizedLimit = limit >= 0 ? limit : Long.MAX_VALUE;
return new IntPipeline.StatefulOp<Integer>(upstream, StreamShape.INT_VALUE,
flags(limit)) {
@Override
long exactOutputSize(long previousSize) {
return calcSize(previousSize, skip, normalizedLimit);
}
Spliterator.OfInt unorderedSkipLimitSpliterator(
Spliterator.OfInt s, long skip, long limit, long sizeIfKnown) {
if (skip <= sizeIfKnown) {
@ -291,9 +298,9 @@ final class SliceOps {
@Override
Sink<Integer> opWrapSink(int flags, Sink<Integer> sink) {
return new Sink.ChainedInt<Integer>(sink) {
return new Sink.ChainedInt<>(sink) {
long n = skip;
long m = limit >= 0 ? limit : Long.MAX_VALUE;
long m = normalizedLimit;
@Override
public void begin(long size) {
@ -335,9 +342,15 @@ final class SliceOps {
long skip, long limit) {
if (skip < 0)
throw new IllegalArgumentException("Skip must be non-negative: " + skip);
long normalizedLimit = limit >= 0 ? limit : Long.MAX_VALUE;
return new LongPipeline.StatefulOp<Long>(upstream, StreamShape.LONG_VALUE,
flags(limit)) {
@Override
long exactOutputSize(long previousSize) {
return calcSize(previousSize, skip, normalizedLimit);
}
Spliterator.OfLong unorderedSkipLimitSpliterator(
Spliterator.OfLong s, long skip, long limit, long sizeIfKnown) {
if (skip <= sizeIfKnown) {
@ -400,9 +413,9 @@ final class SliceOps {
@Override
Sink<Long> opWrapSink(int flags, Sink<Long> sink) {
return new Sink.ChainedLong<Long>(sink) {
return new Sink.ChainedLong<>(sink) {
long n = skip;
long m = limit >= 0 ? limit : Long.MAX_VALUE;
long m = normalizedLimit;
@Override
public void begin(long size) {
@ -444,9 +457,15 @@ final class SliceOps {
long skip, long limit) {
if (skip < 0)
throw new IllegalArgumentException("Skip must be non-negative: " + skip);
long normalizedLimit = limit >= 0 ? limit : Long.MAX_VALUE;
return new DoublePipeline.StatefulOp<Double>(upstream, StreamShape.DOUBLE_VALUE,
flags(limit)) {
@Override
long exactOutputSize(long previousSize) {
return calcSize(previousSize, skip, normalizedLimit);
}
Spliterator.OfDouble unorderedSkipLimitSpliterator(
Spliterator.OfDouble s, long skip, long limit, long sizeIfKnown) {
if (skip <= sizeIfKnown) {
@ -509,9 +528,9 @@ final class SliceOps {
@Override
Sink<Double> opWrapSink(int flags, Sink<Double> sink) {
return new Sink.ChainedDouble<Double>(sink) {
return new Sink.ChainedDouble<>(sink) {
long n = skip;
long m = limit >= 0 ? limit : Long.MAX_VALUE;
long m = normalizedLimit;
@Override
public void begin(long size) {
@ -541,7 +560,7 @@ final class SliceOps {
}
private static int flags(long limit) {
return StreamOpFlag.NOT_SIZED | ((limit != -1) ? StreamOpFlag.IS_SHORT_CIRCUIT : 0);
return StreamOpFlag.IS_SIZE_ADJUSTING | ((limit != -1) ? StreamOpFlag.IS_SHORT_CIRCUIT : 0);
}
/**