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/* |
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* Copyright (c) 2003, 2006, Oracle and/or its affiliates. All rights reserved. |
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* Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Sun designates this |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Sun in the LICENSE file that accompanied this code. |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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package java.util; |
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|
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import java.util.function.Consumer; |
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import jdk.internal.misc.SharedSecrets; |
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|
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/** |
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* An unbounded priority {@linkplain Queue queue} based on a priority heap. |
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* The elements of the priority queue are ordered according to their |
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* <p>This class and its iterator implement all of the |
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* <em>optional</em> methods of the {@link Collection} and {@link |
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* Iterator} interfaces. The Iterator provided in method {@link |
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* #iterator()} is <em>not</em> guaranteed to traverse the elements of |
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* #iterator()} and the Spliterator provided in method {@link #spliterator()} |
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* are <em>not</em> guaranteed to traverse the elements of |
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* the priority queue in any particular order. If you need ordered |
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* traversal, consider using {@code Arrays.sort(pq.toArray())}. |
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* |
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* ({@code peek}, {@code element}, and {@code size}). |
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* |
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* <p>This class is a member of the |
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* <a href="{@docRoot}/../technotes/guides/collections/index.html"> |
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* <a href="{@docRoot}/java/util/package-summary.html#CollectionsFramework"> |
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* Java Collections Framework</a>. |
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* |
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* @since 1.5 |
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* @author Josh Bloch, Doug Lea |
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* @param <E> the type of elements held in this collection |
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* @param <E> the type of elements held in this queue |
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*/ |
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@SuppressWarnings("unchecked") |
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public class PriorityQueue<E> extends AbstractQueue<E> |
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* heap and each descendant d of n, n <= d. The element with the |
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* lowest value is in queue[0], assuming the queue is nonempty. |
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*/ |
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private transient Object[] queue; |
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transient Object[] queue; // non-private to simplify nested class access |
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|
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/** |
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* The number of elements in the priority queue. |
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*/ |
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private int size = 0; |
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int size; |
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|
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/** |
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* The comparator, or null if priority queue uses elements' |
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* The number of times this priority queue has been |
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* <i>structurally modified</i>. See AbstractList for gory details. |
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*/ |
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< |
private transient int modCount = 0; |
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transient int modCount; // non-private to simplify nested class access |
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|
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/** |
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* Creates a {@code PriorityQueue} with the default initial |
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} |
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|
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/** |
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* Creates a {@code PriorityQueue} with the default initial capacity and |
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* whose elements are ordered according to the specified comparator. |
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* |
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* @param comparator the comparator that will be used to order this |
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* priority queue. If {@code null}, the {@linkplain Comparable |
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* natural ordering} of the elements will be used. |
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* @since 1.8 |
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*/ |
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public PriorityQueue(Comparator<? super E> comparator) { |
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this(DEFAULT_INITIAL_CAPACITY, comparator); |
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} |
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|
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/** |
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* Creates a {@code PriorityQueue} with the specified initial capacity |
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* that orders its elements according to the specified comparator. |
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* |
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* @throws NullPointerException if the specified collection or any |
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* of its elements are null |
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*/ |
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@SuppressWarnings("unchecked") |
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public PriorityQueue(Collection<? extends E> c) { |
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if (c instanceof SortedSet<?>) { |
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SortedSet<? extends E> ss = (SortedSet<? extends E>) c; |
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* @throws NullPointerException if the specified priority queue or any |
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* of its elements are null |
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*/ |
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@SuppressWarnings("unchecked") |
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public PriorityQueue(PriorityQueue<? extends E> c) { |
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this.comparator = (Comparator<? super E>) c.comparator(); |
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initFromPriorityQueue(c); |
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* @throws NullPointerException if the specified sorted set or any |
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* of its elements are null |
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*/ |
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– |
@SuppressWarnings("unchecked") |
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public PriorityQueue(SortedSet<? extends E> c) { |
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this.comparator = (Comparator<? super E>) c.comparator(); |
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initElementsFromCollection(c); |
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} |
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|
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/** Ensures that queue[0] exists, helping peek() and poll(). */ |
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private static Object[] ensureNonEmpty(Object[] es) { |
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return (es.length > 0) ? es : new Object[1]; |
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} |
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|
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private void initFromPriorityQueue(PriorityQueue<? extends E> c) { |
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if (c.getClass() == PriorityQueue.class) { |
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this.queue = c.toArray(); |
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> |
this.queue = ensureNonEmpty(c.toArray()); |
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this.size = c.size(); |
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} else { |
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initFromCollection(c); |
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} |
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|
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private void initElementsFromCollection(Collection<? extends E> c) { |
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Object[] a = c.toArray(); |
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> |
Object[] es = c.toArray(); |
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> |
int len = es.length; |
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// If c.toArray incorrectly doesn't return Object[], copy it. |
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< |
if (a.getClass() != Object[].class) |
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a = Arrays.copyOf(a, a.length, Object[].class); |
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int len = a.length; |
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> |
if (es.getClass() != Object[].class) |
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> |
es = Arrays.copyOf(es, len, Object[].class); |
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if (len == 1 || this.comparator != null) |
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for (int i = 0; i < len; i++) |
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< |
if (a[i] == null) |
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> |
for (Object e : es) |
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> |
if (e == null) |
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throw new NullPointerException(); |
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< |
this.queue = a; |
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< |
this.size = a.length; |
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> |
this.queue = ensureNonEmpty(es); |
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> |
this.size = len; |
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} |
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|
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/** |
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int i = size; |
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if (i >= queue.length) |
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grow(i + 1); |
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siftUp(i, e); |
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size = i + 1; |
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if (i == 0) |
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queue[0] = e; |
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else |
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siftUp(i, e); |
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return true; |
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} |
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|
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public E peek() { |
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return (size == 0) ? null : (E) queue[0]; |
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return (E) queue[0]; |
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} |
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|
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private int indexOf(Object o) { |
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if (o != null) { |
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< |
for (int i = 0; i < size; i++) |
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< |
if (o.equals(queue[i])) |
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> |
final Object[] es = queue; |
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> |
for (int i = 0, n = size; i < n; i++) |
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> |
if (o.equals(es[i])) |
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return i; |
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} |
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return -1; |
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} |
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|
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/** |
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* Version of remove using reference equality, not equals. |
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* Needed by iterator.remove. |
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* Identity-based version for use in Itr.remove. |
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* |
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* @param o element to be removed from this queue, if present |
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* @return {@code true} if removed |
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*/ |
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boolean removeEq(Object o) { |
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for (int i = 0; i < size; i++) { |
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< |
if (o == queue[i]) { |
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> |
void removeEq(Object o) { |
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> |
final Object[] es = queue; |
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> |
for (int i = 0, n = size; i < n; i++) { |
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> |
if (o == es[i]) { |
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removeAt(i); |
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< |
return true; |
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> |
break; |
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} |
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} |
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– |
return false; |
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} |
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|
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/** |
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* @return {@code true} if this queue contains the specified element |
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*/ |
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public boolean contains(Object o) { |
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return indexOf(o) != -1; |
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> |
return indexOf(o) >= 0; |
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} |
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|
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/** |
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* The following code can be used to dump the queue into a newly |
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* allocated array of {@code String}: |
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* |
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< |
* <pre> {@code String[] y = x.toArray(new String[0]);}</pre> |
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> |
* <pre> {@code String[] y = x.toArray(new String[0]);}</pre> |
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* |
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* Note that {@code toArray(new Object[0])} is identical in function to |
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* {@code toArray()}. |
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* @throws NullPointerException if the specified array is null |
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*/ |
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public <T> T[] toArray(T[] a) { |
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final int size = this.size; |
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if (a.length < size) |
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// Make a new array of a's runtime type, but my contents: |
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return (T[]) Arrays.copyOf(queue, size, a.getClass()); |
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* Index (into queue array) of element to be returned by |
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* subsequent call to next. |
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*/ |
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< |
private int cursor = 0; |
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> |
private int cursor; |
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|
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/** |
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* Index of element returned by most recent call to next, |
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* We expect that most iterations, even those involving removals, |
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* will not need to store elements in this field. |
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*/ |
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< |
private ArrayDeque<E> forgetMeNot = null; |
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> |
private ArrayDeque<E> forgetMeNot; |
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|
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/** |
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* Element returned by the most recent call to next iff that |
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* element was drawn from the forgetMeNot list. |
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*/ |
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< |
private E lastRetElt = null; |
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> |
private E lastRetElt; |
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|
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/** |
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* The modCount value that the iterator believes that the backing |
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*/ |
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private int expectedModCount = modCount; |
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|
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+ |
Itr() {} // prevent access constructor creation |
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+ |
|
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public boolean hasNext() { |
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return cursor < size || |
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(forgetMeNot != null && !forgetMeNot.isEmpty()); |
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cursor--; |
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else { |
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if (forgetMeNot == null) |
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< |
forgetMeNot = new ArrayDeque<E>(); |
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> |
forgetMeNot = new ArrayDeque<>(); |
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forgetMeNot.add(moved); |
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} |
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} else if (lastRetElt != null) { |
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*/ |
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public void clear() { |
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modCount++; |
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< |
for (int i = 0; i < size; i++) |
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< |
queue[i] = null; |
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> |
final Object[] es = queue; |
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> |
for (int i = 0, n = size; i < n; i++) |
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> |
es[i] = null; |
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size = 0; |
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} |
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|
|
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public E poll() { |
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< |
if (size == 0) |
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< |
return null; |
| 589 |
< |
int s = --size; |
| 590 |
< |
modCount++; |
| 591 |
< |
E result = (E) queue[0]; |
| 592 |
< |
E x = (E) queue[s]; |
| 593 |
< |
queue[s] = null; |
| 594 |
< |
if (s != 0) |
| 595 |
< |
siftDown(0, x); |
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> |
final Object[] es; |
| 588 |
> |
final E result; |
| 589 |
> |
|
| 590 |
> |
if ((result = (E) ((es = queue)[0])) != null) { |
| 591 |
> |
modCount++; |
| 592 |
> |
final int n; |
| 593 |
> |
final E x = (E) es[(n = --size)]; |
| 594 |
> |
es[n] = null; |
| 595 |
> |
if (n > 0) { |
| 596 |
> |
final Comparator<? super E> cmp; |
| 597 |
> |
if ((cmp = comparator) == null) |
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> |
siftDownComparable(0, x, es, n); |
| 599 |
> |
else |
| 600 |
> |
siftDownUsingComparator(0, x, es, n, cmp); |
| 601 |
> |
} |
| 602 |
> |
} |
| 603 |
|
return result; |
| 604 |
|
} |
| 605 |
|
|
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|
* position before i. This fact is used by iterator.remove so as to |
| 616 |
|
* avoid missing traversing elements. |
| 617 |
|
*/ |
| 618 |
< |
private E removeAt(int i) { |
| 618 |
> |
E removeAt(int i) { |
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|
// assert i >= 0 && i < size; |
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+ |
final Object[] es = queue; |
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|
modCount++; |
| 622 |
|
int s = --size; |
| 623 |
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if (s == i) // removed last element |
| 624 |
< |
queue[i] = null; |
| 624 |
> |
es[i] = null; |
| 625 |
|
else { |
| 626 |
< |
E moved = (E) queue[s]; |
| 627 |
< |
queue[s] = null; |
| 626 |
> |
E moved = (E) es[s]; |
| 627 |
> |
es[s] = null; |
| 628 |
|
siftDown(i, moved); |
| 629 |
< |
if (queue[i] == moved) { |
| 629 |
> |
if (es[i] == moved) { |
| 630 |
|
siftUp(i, moved); |
| 631 |
< |
if (queue[i] != moved) |
| 631 |
> |
if (es[i] != moved) |
| 632 |
|
return moved; |
| 633 |
|
} |
| 634 |
|
} |
| 640 |
|
* promoting x up the tree until it is greater than or equal to |
| 641 |
|
* its parent, or is the root. |
| 642 |
|
* |
| 643 |
< |
* To simplify and speed up coercions and comparisons. the |
| 643 |
> |
* To simplify and speed up coercions and comparisons, the |
| 644 |
|
* Comparable and Comparator versions are separated into different |
| 645 |
|
* methods that are otherwise identical. (Similarly for siftDown.) |
| 646 |
|
* |
| 649 |
|
*/ |
| 650 |
|
private void siftUp(int k, E x) { |
| 651 |
|
if (comparator != null) |
| 652 |
< |
siftUpUsingComparator(k, x); |
| 652 |
> |
siftUpUsingComparator(k, x, queue, comparator); |
| 653 |
|
else |
| 654 |
< |
siftUpComparable(k, x); |
| 654 |
> |
siftUpComparable(k, x, queue); |
| 655 |
|
} |
| 656 |
|
|
| 657 |
< |
private void siftUpComparable(int k, E x) { |
| 658 |
< |
Comparable<? super E> key = (Comparable<? super E>) x; |
| 657 |
> |
private static <T> void siftUpComparable(int k, T x, Object[] es) { |
| 658 |
> |
Comparable<? super T> key = (Comparable<? super T>) x; |
| 659 |
|
while (k > 0) { |
| 660 |
|
int parent = (k - 1) >>> 1; |
| 661 |
< |
Object e = queue[parent]; |
| 662 |
< |
if (key.compareTo((E) e) >= 0) |
| 661 |
> |
Object e = es[parent]; |
| 662 |
> |
if (key.compareTo((T) e) >= 0) |
| 663 |
|
break; |
| 664 |
< |
queue[k] = e; |
| 664 |
> |
es[k] = e; |
| 665 |
|
k = parent; |
| 666 |
|
} |
| 667 |
< |
queue[k] = key; |
| 667 |
> |
es[k] = key; |
| 668 |
|
} |
| 669 |
|
|
| 670 |
< |
private void siftUpUsingComparator(int k, E x) { |
| 670 |
> |
private static <T> void siftUpUsingComparator( |
| 671 |
> |
int k, T x, Object[] es, Comparator<? super T> cmp) { |
| 672 |
|
while (k > 0) { |
| 673 |
|
int parent = (k - 1) >>> 1; |
| 674 |
< |
Object e = queue[parent]; |
| 675 |
< |
if (comparator.compare(x, (E) e) >= 0) |
| 674 |
> |
Object e = es[parent]; |
| 675 |
> |
if (cmp.compare(x, (T) e) >= 0) |
| 676 |
|
break; |
| 677 |
< |
queue[k] = e; |
| 677 |
> |
es[k] = e; |
| 678 |
|
k = parent; |
| 679 |
|
} |
| 680 |
< |
queue[k] = x; |
| 680 |
> |
es[k] = x; |
| 681 |
|
} |
| 682 |
|
|
| 683 |
|
/** |
| 690 |
|
*/ |
| 691 |
|
private void siftDown(int k, E x) { |
| 692 |
|
if (comparator != null) |
| 693 |
< |
siftDownUsingComparator(k, x); |
| 693 |
> |
siftDownUsingComparator(k, x, queue, size, comparator); |
| 694 |
|
else |
| 695 |
< |
siftDownComparable(k, x); |
| 695 |
> |
siftDownComparable(k, x, queue, size); |
| 696 |
|
} |
| 697 |
|
|
| 698 |
< |
private void siftDownComparable(int k, E x) { |
| 699 |
< |
Comparable<? super E> key = (Comparable<? super E>)x; |
| 700 |
< |
int half = size >>> 1; // loop while a non-leaf |
| 698 |
> |
private static <T> void siftDownComparable(int k, T x, Object[] es, int n) { |
| 699 |
> |
// assert n > 0; |
| 700 |
> |
Comparable<? super T> key = (Comparable<? super T>)x; |
| 701 |
> |
int half = n >>> 1; // loop while a non-leaf |
| 702 |
|
while (k < half) { |
| 703 |
|
int child = (k << 1) + 1; // assume left child is least |
| 704 |
< |
Object c = queue[child]; |
| 704 |
> |
Object c = es[child]; |
| 705 |
|
int right = child + 1; |
| 706 |
< |
if (right < size && |
| 707 |
< |
((Comparable<? super E>) c).compareTo((E) queue[right]) > 0) |
| 708 |
< |
c = queue[child = right]; |
| 709 |
< |
if (key.compareTo((E) c) <= 0) |
| 706 |
> |
if (right < n && |
| 707 |
> |
((Comparable<? super T>) c).compareTo((T) es[right]) > 0) |
| 708 |
> |
c = es[child = right]; |
| 709 |
> |
if (key.compareTo((T) c) <= 0) |
| 710 |
|
break; |
| 711 |
< |
queue[k] = c; |
| 711 |
> |
es[k] = c; |
| 712 |
|
k = child; |
| 713 |
|
} |
| 714 |
< |
queue[k] = key; |
| 714 |
> |
es[k] = key; |
| 715 |
|
} |
| 716 |
|
|
| 717 |
< |
private void siftDownUsingComparator(int k, E x) { |
| 718 |
< |
int half = size >>> 1; |
| 717 |
> |
private static <T> void siftDownUsingComparator( |
| 718 |
> |
int k, T x, Object[] es, int n, Comparator<? super T> cmp) { |
| 719 |
> |
// assert n > 0; |
| 720 |
> |
int half = n >>> 1; |
| 721 |
|
while (k < half) { |
| 722 |
|
int child = (k << 1) + 1; |
| 723 |
< |
Object c = queue[child]; |
| 723 |
> |
Object c = es[child]; |
| 724 |
|
int right = child + 1; |
| 725 |
< |
if (right < size && |
| 726 |
< |
comparator.compare((E) c, (E) queue[right]) > 0) |
| 727 |
< |
c = queue[child = right]; |
| 697 |
< |
if (comparator.compare(x, (E) c) <= 0) |
| 725 |
> |
if (right < n && cmp.compare((T) c, (T) es[right]) > 0) |
| 726 |
> |
c = es[child = right]; |
| 727 |
> |
if (cmp.compare(x, (T) c) <= 0) |
| 728 |
|
break; |
| 729 |
< |
queue[k] = c; |
| 729 |
> |
es[k] = c; |
| 730 |
|
k = child; |
| 731 |
|
} |
| 732 |
< |
queue[k] = x; |
| 732 |
> |
es[k] = x; |
| 733 |
|
} |
| 734 |
|
|
| 735 |
|
/** |
| 736 |
|
* Establishes the heap invariant (described above) in the entire tree, |
| 737 |
|
* assuming nothing about the order of the elements prior to the call. |
| 738 |
+ |
* This classic algorithm due to Floyd (1964) is known to be O(size). |
| 739 |
|
*/ |
| 740 |
|
private void heapify() { |
| 741 |
< |
for (int i = (size >>> 1) - 1; i >= 0; i--) |
| 742 |
< |
siftDown(i, (E) queue[i]); |
| 741 |
> |
final Object[] es = queue; |
| 742 |
> |
int n = size, i = (n >>> 1) - 1; |
| 743 |
> |
final Comparator<? super E> cmp; |
| 744 |
> |
if ((cmp = comparator) == null) |
| 745 |
> |
for (; i >= 0; i--) |
| 746 |
> |
siftDownComparable(i, (E) es[i], es, n); |
| 747 |
> |
else |
| 748 |
> |
for (; i >= 0; i--) |
| 749 |
> |
siftDownUsingComparator(i, (E) es[i], es, n, cmp); |
| 750 |
|
} |
| 751 |
|
|
| 752 |
|
/** |
| 765 |
|
/** |
| 766 |
|
* Saves this queue to a stream (that is, serializes it). |
| 767 |
|
* |
| 768 |
+ |
* @param s the stream |
| 769 |
+ |
* @throws java.io.IOException if an I/O error occurs |
| 770 |
|
* @serialData The length of the array backing the instance is |
| 771 |
|
* emitted (int), followed by all of its elements |
| 772 |
|
* (each an {@code Object}) in the proper order. |
| 780 |
|
s.writeInt(Math.max(2, size + 1)); |
| 781 |
|
|
| 782 |
|
// Write out all elements in the "proper order". |
| 783 |
< |
for (int i = 0; i < size; i++) |
| 784 |
< |
s.writeObject(queue[i]); |
| 783 |
> |
final Object[] es = queue; |
| 784 |
> |
for (int i = 0, n = size; i < n; i++) |
| 785 |
> |
s.writeObject(es[i]); |
| 786 |
|
} |
| 787 |
|
|
| 788 |
|
/** |
| 789 |
< |
* Reconstitutes this queue from a stream (that is, deserializes it). |
| 789 |
> |
* Reconstitutes the {@code PriorityQueue} instance from a stream |
| 790 |
> |
* (that is, deserializes it). |
| 791 |
> |
* |
| 792 |
> |
* @param s the stream |
| 793 |
> |
* @throws ClassNotFoundException if the class of a serialized object |
| 794 |
> |
* could not be found |
| 795 |
> |
* @throws java.io.IOException if an I/O error occurs |
| 796 |
|
*/ |
| 797 |
|
private void readObject(java.io.ObjectInputStream s) |
| 798 |
|
throws java.io.IOException, ClassNotFoundException { |
| 802 |
|
// Read in (and discard) array length |
| 803 |
|
s.readInt(); |
| 804 |
|
|
| 805 |
< |
queue = new Object[size]; |
| 805 |
> |
SharedSecrets.getJavaObjectInputStreamAccess().checkArray(s, Object[].class, size); |
| 806 |
> |
final Object[] es = queue = new Object[Math.max(size, 1)]; |
| 807 |
|
|
| 808 |
|
// Read in all elements. |
| 809 |
< |
for (int i = 0; i < size; i++) |
| 810 |
< |
queue[i] = s.readObject(); |
| 809 |
> |
for (int i = 0, n = size; i < n; i++) |
| 810 |
> |
es[i] = s.readObject(); |
| 811 |
|
|
| 812 |
|
// Elements are guaranteed to be in "proper order", but the |
| 813 |
|
// spec has never explained what that might be. |
| 814 |
|
heapify(); |
| 815 |
|
} |
| 816 |
+ |
|
| 817 |
+ |
/** |
| 818 |
+ |
* Creates a <em><a href="Spliterator.html#binding">late-binding</a></em> |
| 819 |
+ |
* and <em>fail-fast</em> {@link Spliterator} over the elements in this |
| 820 |
+ |
* queue. The spliterator does not traverse elements in any particular order |
| 821 |
+ |
* (the {@link Spliterator#ORDERED ORDERED} characteristic is not reported). |
| 822 |
+ |
* |
| 823 |
+ |
* <p>The {@code Spliterator} reports {@link Spliterator#SIZED}, |
| 824 |
+ |
* {@link Spliterator#SUBSIZED}, and {@link Spliterator#NONNULL}. |
| 825 |
+ |
* Overriding implementations should document the reporting of additional |
| 826 |
+ |
* characteristic values. |
| 827 |
+ |
* |
| 828 |
+ |
* @return a {@code Spliterator} over the elements in this queue |
| 829 |
+ |
* @since 1.8 |
| 830 |
+ |
*/ |
| 831 |
+ |
public final Spliterator<E> spliterator() { |
| 832 |
+ |
return new PriorityQueueSpliterator(0, -1, 0); |
| 833 |
+ |
} |
| 834 |
+ |
|
| 835 |
+ |
final class PriorityQueueSpliterator implements Spliterator<E> { |
| 836 |
+ |
private int index; // current index, modified on advance/split |
| 837 |
+ |
private int fence; // -1 until first use |
| 838 |
+ |
private int expectedModCount; // initialized when fence set |
| 839 |
+ |
|
| 840 |
+ |
/** Creates new spliterator covering the given range. */ |
| 841 |
+ |
PriorityQueueSpliterator(int origin, int fence, int expectedModCount) { |
| 842 |
+ |
this.index = origin; |
| 843 |
+ |
this.fence = fence; |
| 844 |
+ |
this.expectedModCount = expectedModCount; |
| 845 |
+ |
} |
| 846 |
+ |
|
| 847 |
+ |
private int getFence() { // initialize fence to size on first use |
| 848 |
+ |
int hi; |
| 849 |
+ |
if ((hi = fence) < 0) { |
| 850 |
+ |
expectedModCount = modCount; |
| 851 |
+ |
hi = fence = size; |
| 852 |
+ |
} |
| 853 |
+ |
return hi; |
| 854 |
+ |
} |
| 855 |
+ |
|
| 856 |
+ |
public PriorityQueueSpliterator trySplit() { |
| 857 |
+ |
int hi = getFence(), lo = index, mid = (lo + hi) >>> 1; |
| 858 |
+ |
return (lo >= mid) ? null : |
| 859 |
+ |
new PriorityQueueSpliterator(lo, index = mid, expectedModCount); |
| 860 |
+ |
} |
| 861 |
+ |
|
| 862 |
+ |
public void forEachRemaining(Consumer<? super E> action) { |
| 863 |
+ |
if (action == null) |
| 864 |
+ |
throw new NullPointerException(); |
| 865 |
+ |
if (fence < 0) { fence = size; expectedModCount = modCount; } |
| 866 |
+ |
final Object[] es = queue; |
| 867 |
+ |
int i, hi; E e; |
| 868 |
+ |
for (i = index, index = hi = fence; i < hi; i++) { |
| 869 |
+ |
if ((e = (E) es[i]) == null) |
| 870 |
+ |
break; // must be CME |
| 871 |
+ |
action.accept(e); |
| 872 |
+ |
} |
| 873 |
+ |
if (modCount != expectedModCount) |
| 874 |
+ |
throw new ConcurrentModificationException(); |
| 875 |
+ |
} |
| 876 |
+ |
|
| 877 |
+ |
public boolean tryAdvance(Consumer<? super E> action) { |
| 878 |
+ |
if (action == null) |
| 879 |
+ |
throw new NullPointerException(); |
| 880 |
+ |
if (fence < 0) { fence = size; expectedModCount = modCount; } |
| 881 |
+ |
int i; |
| 882 |
+ |
if ((i = index) < fence) { |
| 883 |
+ |
index = i + 1; |
| 884 |
+ |
E e; |
| 885 |
+ |
if ((e = (E) queue[i]) == null |
| 886 |
+ |
|| modCount != expectedModCount) |
| 887 |
+ |
throw new ConcurrentModificationException(); |
| 888 |
+ |
action.accept(e); |
| 889 |
+ |
return true; |
| 890 |
+ |
} |
| 891 |
+ |
return false; |
| 892 |
+ |
} |
| 893 |
+ |
|
| 894 |
+ |
public long estimateSize() { |
| 895 |
+ |
return getFence() - index; |
| 896 |
+ |
} |
| 897 |
+ |
|
| 898 |
+ |
public int characteristics() { |
| 899 |
+ |
return Spliterator.SIZED | Spliterator.SUBSIZED | Spliterator.NONNULL; |
| 900 |
+ |
} |
| 901 |
+ |
} |
| 902 |
+ |
|
| 903 |
+ |
/** |
| 904 |
+ |
* @throws NullPointerException {@inheritDoc} |
| 905 |
+ |
*/ |
| 906 |
+ |
public void forEach(Consumer<? super E> action) { |
| 907 |
+ |
Objects.requireNonNull(action); |
| 908 |
+ |
final int expectedModCount = modCount; |
| 909 |
+ |
final Object[] es = queue; |
| 910 |
+ |
for (int i = 0, n = size; i < n; i++) |
| 911 |
+ |
action.accept((E) es[i]); |
| 912 |
+ |
if (expectedModCount != modCount) |
| 913 |
+ |
throw new ConcurrentModificationException(); |
| 914 |
+ |
} |
| 915 |
|
} |
