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/* |
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* Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved. |
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* Copyright (c) 2003, 2019, 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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package java.util; |
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import java.util.function.Consumer; |
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import java.util.function.Predicate; |
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// OPENJDK import jdk.internal.access.SharedSecrets; |
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import jdk.internal.util.ArraysSupport; |
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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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* <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.base/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 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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implements java.io.Serializable { |
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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 (Object e : a) |
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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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} |
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|
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/** |
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– |
* The maximum size of array to allocate. |
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– |
* Some VMs reserve some header words in an array. |
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– |
* Attempts to allocate larger arrays may result in |
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* OutOfMemoryError: Requested array size exceeds VM limit |
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– |
*/ |
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– |
private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8; |
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– |
|
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– |
/** |
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* Increases the capacity of the array. |
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* |
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* @param minCapacity the desired minimum capacity |
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private void grow(int minCapacity) { |
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int oldCapacity = queue.length; |
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// Double size if small; else grow by 50% |
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< |
int newCapacity = oldCapacity + ((oldCapacity < 64) ? |
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< |
(oldCapacity + 2) : |
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< |
(oldCapacity >> 1)); |
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< |
// overflow-conscious code |
| 298 |
< |
if (newCapacity - MAX_ARRAY_SIZE > 0) |
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< |
newCapacity = hugeCapacity(minCapacity); |
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> |
int newCapacity = ArraysSupport.newLength(oldCapacity, |
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> |
minCapacity - oldCapacity, /* minimum growth */ |
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> |
oldCapacity < 64 ? oldCapacity + 2 : oldCapacity >> 1 |
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> |
/* preferred growth */); |
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queue = Arrays.copyOf(queue, newCapacity); |
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} |
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|
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– |
private static int hugeCapacity(int minCapacity) { |
| 304 |
– |
if (minCapacity < 0) // overflow |
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– |
throw new OutOfMemoryError(); |
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– |
return (minCapacity > MAX_ARRAY_SIZE) ? |
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– |
Integer.MAX_VALUE : |
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– |
MAX_ARRAY_SIZE; |
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– |
} |
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– |
|
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/** |
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* Inserts the specified element into this priority queue. |
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* |
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return true; |
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} |
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|
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– |
@SuppressWarnings("unchecked") |
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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. |
| 370 |
> |
* 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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*/ |
| 374 |
< |
boolean removeEq(Object o) { |
| 375 |
< |
for (int i = 0; i < size; i++) { |
| 376 |
< |
if (o == queue[i]) { |
| 374 |
> |
void removeEq(Object o) { |
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> |
final Object[] es = queue; |
| 376 |
> |
for (int i = 0, n = size; i < n; i++) { |
| 377 |
> |
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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|
| 384 |
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/** |
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* this queue |
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* @throws NullPointerException if the specified array is null |
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*/ |
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– |
@SuppressWarnings("unchecked") |
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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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*/ |
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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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} |
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|
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– |
@SuppressWarnings("unchecked") |
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public E next() { |
| 518 |
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if (expectedModCount != modCount) |
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throw new ConcurrentModificationException(); |
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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++) |
| 565 |
< |
queue[i] = null; |
| 564 |
> |
final Object[] es = queue; |
| 565 |
> |
for (int i = 0, n = size; i < n; i++) |
| 566 |
> |
es[i] = null; |
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size = 0; |
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} |
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|
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– |
@SuppressWarnings("unchecked") |
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public E poll() { |
| 571 |
< |
if (size == 0) |
| 572 |
< |
return null; |
| 573 |
< |
int s = --size; |
| 574 |
< |
modCount++; |
| 575 |
< |
E result = (E) queue[0]; |
| 576 |
< |
E x = (E) queue[s]; |
| 577 |
< |
queue[s] = null; |
| 578 |
< |
if (s != 0) |
| 579 |
< |
siftDown(0, x); |
| 571 |
> |
final Object[] es; |
| 572 |
> |
final E result; |
| 573 |
> |
|
| 574 |
> |
if ((result = (E) ((es = queue)[0])) != null) { |
| 575 |
> |
modCount++; |
| 576 |
> |
final int n; |
| 577 |
> |
final E x = (E) es[(n = --size)]; |
| 578 |
> |
es[n] = null; |
| 579 |
> |
if (n > 0) { |
| 580 |
> |
final Comparator<? super E> cmp; |
| 581 |
> |
if ((cmp = comparator) == null) |
| 582 |
> |
siftDownComparable(0, x, es, n); |
| 583 |
> |
else |
| 584 |
> |
siftDownUsingComparator(0, x, es, n, cmp); |
| 585 |
> |
} |
| 586 |
> |
} |
| 587 |
|
return result; |
| 588 |
|
} |
| 589 |
|
|
| 599 |
|
* position before i. This fact is used by iterator.remove so as to |
| 600 |
|
* avoid missing traversing elements. |
| 601 |
|
*/ |
| 608 |
– |
@SuppressWarnings("unchecked") |
| 602 |
|
E removeAt(int i) { |
| 603 |
|
// assert i >= 0 && i < size; |
| 604 |
+ |
final Object[] es = queue; |
| 605 |
|
modCount++; |
| 606 |
|
int s = --size; |
| 607 |
|
if (s == i) // removed last element |
| 608 |
< |
queue[i] = null; |
| 608 |
> |
es[i] = null; |
| 609 |
|
else { |
| 610 |
< |
E moved = (E) queue[s]; |
| 611 |
< |
queue[s] = null; |
| 610 |
> |
E moved = (E) es[s]; |
| 611 |
> |
es[s] = null; |
| 612 |
|
siftDown(i, moved); |
| 613 |
< |
if (queue[i] == moved) { |
| 613 |
> |
if (es[i] == moved) { |
| 614 |
|
siftUp(i, moved); |
| 615 |
< |
if (queue[i] != moved) |
| 615 |
> |
if (es[i] != moved) |
| 616 |
|
return moved; |
| 617 |
|
} |
| 618 |
|
} |
| 624 |
|
* promoting x up the tree until it is greater than or equal to |
| 625 |
|
* its parent, or is the root. |
| 626 |
|
* |
| 627 |
< |
* To simplify and speed up coercions and comparisons. the |
| 627 |
> |
* To simplify and speed up coercions and comparisons, the |
| 628 |
|
* Comparable and Comparator versions are separated into different |
| 629 |
|
* methods that are otherwise identical. (Similarly for siftDown.) |
| 630 |
|
* |
| 633 |
|
*/ |
| 634 |
|
private void siftUp(int k, E x) { |
| 635 |
|
if (comparator != null) |
| 636 |
< |
siftUpUsingComparator(k, x); |
| 636 |
> |
siftUpUsingComparator(k, x, queue, comparator); |
| 637 |
|
else |
| 638 |
< |
siftUpComparable(k, x); |
| 638 |
> |
siftUpComparable(k, x, queue); |
| 639 |
|
} |
| 640 |
|
|
| 641 |
< |
@SuppressWarnings("unchecked") |
| 642 |
< |
private void siftUpComparable(int k, E x) { |
| 649 |
< |
Comparable<? super E> key = (Comparable<? super E>) x; |
| 641 |
> |
private static <T> void siftUpComparable(int k, T x, Object[] es) { |
| 642 |
> |
Comparable<? super T> key = (Comparable<? super T>) x; |
| 643 |
|
while (k > 0) { |
| 644 |
|
int parent = (k - 1) >>> 1; |
| 645 |
< |
Object e = queue[parent]; |
| 646 |
< |
if (key.compareTo((E) e) >= 0) |
| 645 |
> |
Object e = es[parent]; |
| 646 |
> |
if (key.compareTo((T) e) >= 0) |
| 647 |
|
break; |
| 648 |
< |
queue[k] = e; |
| 648 |
> |
es[k] = e; |
| 649 |
|
k = parent; |
| 650 |
|
} |
| 651 |
< |
queue[k] = key; |
| 651 |
> |
es[k] = key; |
| 652 |
|
} |
| 653 |
|
|
| 654 |
< |
@SuppressWarnings("unchecked") |
| 655 |
< |
private void siftUpUsingComparator(int k, E x) { |
| 654 |
> |
private static <T> void siftUpUsingComparator( |
| 655 |
> |
int k, T x, Object[] es, Comparator<? super T> cmp) { |
| 656 |
|
while (k > 0) { |
| 657 |
|
int parent = (k - 1) >>> 1; |
| 658 |
< |
Object e = queue[parent]; |
| 659 |
< |
if (comparator.compare(x, (E) e) >= 0) |
| 658 |
> |
Object e = es[parent]; |
| 659 |
> |
if (cmp.compare(x, (T) e) >= 0) |
| 660 |
|
break; |
| 661 |
< |
queue[k] = e; |
| 661 |
> |
es[k] = e; |
| 662 |
|
k = parent; |
| 663 |
|
} |
| 664 |
< |
queue[k] = x; |
| 664 |
> |
es[k] = x; |
| 665 |
|
} |
| 666 |
|
|
| 667 |
|
/** |
| 674 |
|
*/ |
| 675 |
|
private void siftDown(int k, E x) { |
| 676 |
|
if (comparator != null) |
| 677 |
< |
siftDownUsingComparator(k, x); |
| 677 |
> |
siftDownUsingComparator(k, x, queue, size, comparator); |
| 678 |
|
else |
| 679 |
< |
siftDownComparable(k, x); |
| 679 |
> |
siftDownComparable(k, x, queue, size); |
| 680 |
|
} |
| 681 |
|
|
| 682 |
< |
@SuppressWarnings("unchecked") |
| 683 |
< |
private void siftDownComparable(int k, E x) { |
| 684 |
< |
Comparable<? super E> key = (Comparable<? super E>)x; |
| 685 |
< |
int half = size >>> 1; // loop while a non-leaf |
| 682 |
> |
private static <T> void siftDownComparable(int k, T x, Object[] es, int n) { |
| 683 |
> |
// assert n > 0; |
| 684 |
> |
Comparable<? super T> key = (Comparable<? super T>)x; |
| 685 |
> |
int half = n >>> 1; // loop while a non-leaf |
| 686 |
|
while (k < half) { |
| 687 |
|
int child = (k << 1) + 1; // assume left child is least |
| 688 |
< |
Object c = queue[child]; |
| 688 |
> |
Object c = es[child]; |
| 689 |
|
int right = child + 1; |
| 690 |
< |
if (right < size && |
| 691 |
< |
((Comparable<? super E>) c).compareTo((E) queue[right]) > 0) |
| 692 |
< |
c = queue[child = right]; |
| 693 |
< |
if (key.compareTo((E) c) <= 0) |
| 690 |
> |
if (right < n && |
| 691 |
> |
((Comparable<? super T>) c).compareTo((T) es[right]) > 0) |
| 692 |
> |
c = es[child = right]; |
| 693 |
> |
if (key.compareTo((T) c) <= 0) |
| 694 |
|
break; |
| 695 |
< |
queue[k] = c; |
| 695 |
> |
es[k] = c; |
| 696 |
|
k = child; |
| 697 |
|
} |
| 698 |
< |
queue[k] = key; |
| 698 |
> |
es[k] = key; |
| 699 |
|
} |
| 700 |
|
|
| 701 |
< |
@SuppressWarnings("unchecked") |
| 702 |
< |
private void siftDownUsingComparator(int k, E x) { |
| 703 |
< |
int half = size >>> 1; |
| 701 |
> |
private static <T> void siftDownUsingComparator( |
| 702 |
> |
int k, T x, Object[] es, int n, Comparator<? super T> cmp) { |
| 703 |
> |
// assert n > 0; |
| 704 |
> |
int half = n >>> 1; |
| 705 |
|
while (k < half) { |
| 706 |
|
int child = (k << 1) + 1; |
| 707 |
< |
Object c = queue[child]; |
| 707 |
> |
Object c = es[child]; |
| 708 |
|
int right = child + 1; |
| 709 |
< |
if (right < size && |
| 710 |
< |
comparator.compare((E) c, (E) queue[right]) > 0) |
| 711 |
< |
c = queue[child = right]; |
| 718 |
< |
if (comparator.compare(x, (E) c) <= 0) |
| 709 |
> |
if (right < n && cmp.compare((T) c, (T) es[right]) > 0) |
| 710 |
> |
c = es[child = right]; |
| 711 |
> |
if (cmp.compare(x, (T) c) <= 0) |
| 712 |
|
break; |
| 713 |
< |
queue[k] = c; |
| 713 |
> |
es[k] = c; |
| 714 |
|
k = child; |
| 715 |
|
} |
| 716 |
< |
queue[k] = x; |
| 716 |
> |
es[k] = x; |
| 717 |
|
} |
| 718 |
|
|
| 719 |
|
/** |
| 720 |
|
* Establishes the heap invariant (described above) in the entire tree, |
| 721 |
|
* assuming nothing about the order of the elements prior to the call. |
| 722 |
+ |
* This classic algorithm due to Floyd (1964) is known to be O(size). |
| 723 |
|
*/ |
| 730 |
– |
@SuppressWarnings("unchecked") |
| 724 |
|
private void heapify() { |
| 725 |
< |
for (int i = (size >>> 1) - 1; i >= 0; i--) |
| 726 |
< |
siftDown(i, (E) queue[i]); |
| 725 |
> |
final Object[] es = queue; |
| 726 |
> |
int n = size, i = (n >>> 1) - 1; |
| 727 |
> |
final Comparator<? super E> cmp; |
| 728 |
> |
if ((cmp = comparator) == null) |
| 729 |
> |
for (; i >= 0; i--) |
| 730 |
> |
siftDownComparable(i, (E) es[i], es, n); |
| 731 |
> |
else |
| 732 |
> |
for (; i >= 0; i--) |
| 733 |
> |
siftDownUsingComparator(i, (E) es[i], es, n, cmp); |
| 734 |
|
} |
| 735 |
|
|
| 736 |
|
/** |
| 749 |
|
/** |
| 750 |
|
* Saves this queue to a stream (that is, serializes it). |
| 751 |
|
* |
| 752 |
+ |
* @param s the stream |
| 753 |
+ |
* @throws java.io.IOException if an I/O error occurs |
| 754 |
|
* @serialData The length of the array backing the instance is |
| 755 |
|
* emitted (int), followed by all of its elements |
| 756 |
|
* (each an {@code Object}) in the proper order. |
| 755 |
– |
* @param s the stream |
| 756 |
– |
* @throws java.io.IOException if an I/O error occurs |
| 757 |
|
*/ |
| 758 |
|
private void writeObject(java.io.ObjectOutputStream s) |
| 759 |
|
throws java.io.IOException { |
| 764 |
|
s.writeInt(Math.max(2, size + 1)); |
| 765 |
|
|
| 766 |
|
// Write out all elements in the "proper order". |
| 767 |
< |
for (int i = 0; i < size; i++) |
| 768 |
< |
s.writeObject(queue[i]); |
| 767 |
> |
final Object[] es = queue; |
| 768 |
> |
for (int i = 0, n = size; i < n; i++) |
| 769 |
> |
s.writeObject(es[i]); |
| 770 |
|
} |
| 771 |
|
|
| 772 |
|
/** |
| 786 |
|
// Read in (and discard) array length |
| 787 |
|
s.readInt(); |
| 788 |
|
|
| 789 |
< |
queue = new Object[size]; |
| 789 |
> |
jsr166.Platform.checkArray(s, Object[].class, size); |
| 790 |
> |
final Object[] es = queue = new Object[Math.max(size, 1)]; |
| 791 |
|
|
| 792 |
|
// Read in all elements. |
| 793 |
< |
for (int i = 0; i < size; i++) |
| 794 |
< |
queue[i] = s.readObject(); |
| 793 |
> |
for (int i = 0, n = size; i < n; i++) |
| 794 |
> |
es[i] = s.readObject(); |
| 795 |
|
|
| 796 |
|
// Elements are guaranteed to be in "proper order", but the |
| 797 |
|
// spec has never explained what that might be. |
| 801 |
|
/** |
| 802 |
|
* Creates a <em><a href="Spliterator.html#binding">late-binding</a></em> |
| 803 |
|
* and <em>fail-fast</em> {@link Spliterator} over the elements in this |
| 804 |
< |
* queue. |
| 804 |
> |
* queue. The spliterator does not traverse elements in any particular order |
| 805 |
> |
* (the {@link Spliterator#ORDERED ORDERED} characteristic is not reported). |
| 806 |
|
* |
| 807 |
|
* <p>The {@code Spliterator} reports {@link Spliterator#SIZED}, |
| 808 |
|
* {@link Spliterator#SUBSIZED}, and {@link Spliterator#NONNULL}. |
| 813 |
|
* @since 1.8 |
| 814 |
|
*/ |
| 815 |
|
public final Spliterator<E> spliterator() { |
| 816 |
< |
return new PriorityQueueSpliterator<>(this, 0, -1, 0); |
| 816 |
> |
return new PriorityQueueSpliterator(0, -1, 0); |
| 817 |
|
} |
| 818 |
|
|
| 819 |
< |
static final class PriorityQueueSpliterator<E> implements Spliterator<E> { |
| 817 |
< |
/* |
| 818 |
< |
* This is very similar to ArrayList Spliterator, except for |
| 819 |
< |
* extra null checks. |
| 820 |
< |
*/ |
| 821 |
< |
private final PriorityQueue<E> pq; |
| 819 |
> |
final class PriorityQueueSpliterator implements Spliterator<E> { |
| 820 |
|
private int index; // current index, modified on advance/split |
| 821 |
|
private int fence; // -1 until first use |
| 822 |
|
private int expectedModCount; // initialized when fence set |
| 823 |
|
|
| 824 |
|
/** Creates new spliterator covering the given range. */ |
| 825 |
< |
PriorityQueueSpliterator(PriorityQueue<E> pq, int origin, int fence, |
| 828 |
< |
int expectedModCount) { |
| 829 |
< |
this.pq = pq; |
| 825 |
> |
PriorityQueueSpliterator(int origin, int fence, int expectedModCount) { |
| 826 |
|
this.index = origin; |
| 827 |
|
this.fence = fence; |
| 828 |
|
this.expectedModCount = expectedModCount; |
| 831 |
|
private int getFence() { // initialize fence to size on first use |
| 832 |
|
int hi; |
| 833 |
|
if ((hi = fence) < 0) { |
| 834 |
< |
expectedModCount = pq.modCount; |
| 835 |
< |
hi = fence = pq.size; |
| 834 |
> |
expectedModCount = modCount; |
| 835 |
> |
hi = fence = size; |
| 836 |
|
} |
| 837 |
|
return hi; |
| 838 |
|
} |
| 839 |
|
|
| 840 |
< |
public PriorityQueueSpliterator<E> trySplit() { |
| 840 |
> |
public PriorityQueueSpliterator trySplit() { |
| 841 |
|
int hi = getFence(), lo = index, mid = (lo + hi) >>> 1; |
| 842 |
|
return (lo >= mid) ? null : |
| 843 |
< |
new PriorityQueueSpliterator<>(pq, lo, index = mid, |
| 848 |
< |
expectedModCount); |
| 843 |
> |
new PriorityQueueSpliterator(lo, index = mid, expectedModCount); |
| 844 |
|
} |
| 845 |
|
|
| 851 |
– |
@SuppressWarnings("unchecked") |
| 846 |
|
public void forEachRemaining(Consumer<? super E> action) { |
| 853 |
– |
int i, hi, mc; // hoist accesses and checks from loop |
| 854 |
– |
PriorityQueue<E> q; Object[] a; |
| 847 |
|
if (action == null) |
| 848 |
|
throw new NullPointerException(); |
| 849 |
< |
if ((q = pq) != null && (a = q.queue) != null) { |
| 850 |
< |
if ((hi = fence) < 0) { |
| 851 |
< |
mc = q.modCount; |
| 852 |
< |
hi = q.size; |
| 853 |
< |
} |
| 854 |
< |
else |
| 855 |
< |
mc = expectedModCount; |
| 864 |
< |
if ((i = index) >= 0 && (index = hi) <= a.length) { |
| 865 |
< |
for (E e;; ++i) { |
| 866 |
< |
if (i < hi) { |
| 867 |
< |
if ((e = (E) a[i]) == null) // must be CME |
| 868 |
< |
break; |
| 869 |
< |
action.accept(e); |
| 870 |
< |
} |
| 871 |
< |
else if (q.modCount != mc) |
| 872 |
< |
break; |
| 873 |
< |
else |
| 874 |
< |
return; |
| 875 |
< |
} |
| 876 |
< |
} |
| 849 |
> |
if (fence < 0) { fence = size; expectedModCount = modCount; } |
| 850 |
> |
final Object[] es = queue; |
| 851 |
> |
int i, hi; E e; |
| 852 |
> |
for (i = index, index = hi = fence; i < hi; i++) { |
| 853 |
> |
if ((e = (E) es[i]) == null) |
| 854 |
> |
break; // must be CME |
| 855 |
> |
action.accept(e); |
| 856 |
|
} |
| 857 |
< |
throw new ConcurrentModificationException(); |
| 857 |
> |
if (modCount != expectedModCount) |
| 858 |
> |
throw new ConcurrentModificationException(); |
| 859 |
|
} |
| 860 |
|
|
| 861 |
|
public boolean tryAdvance(Consumer<? super E> action) { |
| 862 |
|
if (action == null) |
| 863 |
|
throw new NullPointerException(); |
| 864 |
< |
int hi = getFence(), lo = index; |
| 865 |
< |
if (lo >= 0 && lo < hi) { |
| 866 |
< |
index = lo + 1; |
| 867 |
< |
@SuppressWarnings("unchecked") E e = (E)pq.queue[lo]; |
| 868 |
< |
if (e == null) |
| 864 |
> |
if (fence < 0) { fence = size; expectedModCount = modCount; } |
| 865 |
> |
int i; |
| 866 |
> |
if ((i = index) < fence) { |
| 867 |
> |
index = i + 1; |
| 868 |
> |
E e; |
| 869 |
> |
if ((e = (E) queue[i]) == null |
| 870 |
> |
|| modCount != expectedModCount) |
| 871 |
|
throw new ConcurrentModificationException(); |
| 872 |
|
action.accept(e); |
| 891 |
– |
if (pq.modCount != expectedModCount) |
| 892 |
– |
throw new ConcurrentModificationException(); |
| 873 |
|
return true; |
| 874 |
|
} |
| 875 |
|
return false; |
| 876 |
|
} |
| 877 |
|
|
| 878 |
|
public long estimateSize() { |
| 879 |
< |
return (long) (getFence() - index); |
| 879 |
> |
return getFence() - index; |
| 880 |
|
} |
| 881 |
|
|
| 882 |
|
public int characteristics() { |
| 883 |
|
return Spliterator.SIZED | Spliterator.SUBSIZED | Spliterator.NONNULL; |
| 884 |
|
} |
| 885 |
|
} |
| 886 |
+ |
|
| 887 |
+ |
/** |
| 888 |
+ |
* @throws NullPointerException {@inheritDoc} |
| 889 |
+ |
*/ |
| 890 |
+ |
public boolean removeIf(Predicate<? super E> filter) { |
| 891 |
+ |
Objects.requireNonNull(filter); |
| 892 |
+ |
return bulkRemove(filter); |
| 893 |
+ |
} |
| 894 |
+ |
|
| 895 |
+ |
/** |
| 896 |
+ |
* @throws NullPointerException {@inheritDoc} |
| 897 |
+ |
*/ |
| 898 |
+ |
public boolean removeAll(Collection<?> c) { |
| 899 |
+ |
Objects.requireNonNull(c); |
| 900 |
+ |
return bulkRemove(e -> c.contains(e)); |
| 901 |
+ |
} |
| 902 |
+ |
|
| 903 |
+ |
/** |
| 904 |
+ |
* @throws NullPointerException {@inheritDoc} |
| 905 |
+ |
*/ |
| 906 |
+ |
public boolean retainAll(Collection<?> c) { |
| 907 |
+ |
Objects.requireNonNull(c); |
| 908 |
+ |
return bulkRemove(e -> !c.contains(e)); |
| 909 |
+ |
} |
| 910 |
+ |
|
| 911 |
+ |
// A tiny bit set implementation |
| 912 |
+ |
|
| 913 |
+ |
private static long[] nBits(int n) { |
| 914 |
+ |
return new long[((n - 1) >> 6) + 1]; |
| 915 |
+ |
} |
| 916 |
+ |
private static void setBit(long[] bits, int i) { |
| 917 |
+ |
bits[i >> 6] |= 1L << i; |
| 918 |
+ |
} |
| 919 |
+ |
private static boolean isClear(long[] bits, int i) { |
| 920 |
+ |
return (bits[i >> 6] & (1L << i)) == 0; |
| 921 |
+ |
} |
| 922 |
+ |
|
| 923 |
+ |
/** Implementation of bulk remove methods. */ |
| 924 |
+ |
private boolean bulkRemove(Predicate<? super E> filter) { |
| 925 |
+ |
final int expectedModCount = ++modCount; |
| 926 |
+ |
final Object[] es = queue; |
| 927 |
+ |
final int end = size; |
| 928 |
+ |
int i; |
| 929 |
+ |
// Optimize for initial run of survivors |
| 930 |
+ |
for (i = 0; i < end && !filter.test((E) es[i]); i++) |
| 931 |
+ |
; |
| 932 |
+ |
if (i >= end) { |
| 933 |
+ |
if (modCount != expectedModCount) |
| 934 |
+ |
throw new ConcurrentModificationException(); |
| 935 |
+ |
return false; |
| 936 |
+ |
} |
| 937 |
+ |
// Tolerate predicates that reentrantly access the collection for |
| 938 |
+ |
// read (but writers still get CME), so traverse once to find |
| 939 |
+ |
// elements to delete, a second pass to physically expunge. |
| 940 |
+ |
final int beg = i; |
| 941 |
+ |
final long[] deathRow = nBits(end - beg); |
| 942 |
+ |
deathRow[0] = 1L; // set bit 0 |
| 943 |
+ |
for (i = beg + 1; i < end; i++) |
| 944 |
+ |
if (filter.test((E) es[i])) |
| 945 |
+ |
setBit(deathRow, i - beg); |
| 946 |
+ |
if (modCount != expectedModCount) |
| 947 |
+ |
throw new ConcurrentModificationException(); |
| 948 |
+ |
int w = beg; |
| 949 |
+ |
for (i = beg; i < end; i++) |
| 950 |
+ |
if (isClear(deathRow, i - beg)) |
| 951 |
+ |
es[w++] = es[i]; |
| 952 |
+ |
for (i = size = w; i < end; i++) |
| 953 |
+ |
es[i] = null; |
| 954 |
+ |
heapify(); |
| 955 |
+ |
return true; |
| 956 |
+ |
} |
| 957 |
+ |
|
| 958 |
+ |
/** |
| 959 |
+ |
* @throws NullPointerException {@inheritDoc} |
| 960 |
+ |
*/ |
| 961 |
+ |
public void forEach(Consumer<? super E> action) { |
| 962 |
+ |
Objects.requireNonNull(action); |
| 963 |
+ |
final int expectedModCount = modCount; |
| 964 |
+ |
final Object[] es = queue; |
| 965 |
+ |
for (int i = 0, n = size; i < n; i++) |
| 966 |
+ |
action.accept((E) es[i]); |
| 967 |
+ |
if (expectedModCount != modCount) |
| 968 |
+ |
throw new ConcurrentModificationException(); |
| 969 |
+ |
} |
| 970 |
|
} |
