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/* |
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* Copyright (c) 2003, 2012, 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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*/ |
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package java.util; |
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import java.util.function.Consumer; |
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import java.util.stream.Stream; |
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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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* 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 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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implements java.io.Serializable { |
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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; |
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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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transient int modCount = 0; // non-private to simplify nested class access |
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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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} |
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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 |
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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) { |
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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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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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@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. |
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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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* 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() { |
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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++) |
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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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@SuppressWarnings("unchecked") |
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public E poll() { |
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if (size == 0) |
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< |
return null; |
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int s = --size; |
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< |
modCount++; |
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E result = (E) queue[0]; |
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E x = (E) queue[s]; |
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queue[s] = null; |
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if (s != 0) |
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siftDown(0, x); |
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final Object[] es; |
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> |
final E result; |
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> |
|
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> |
if ((result = (E) ((es = queue)[0])) != null) { |
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> |
modCount++; |
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> |
final int n; |
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> |
final E x = (E) es[(n = --size)]; |
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es[n] = null; |
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if (n > 0) { |
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> |
final Comparator<? super E> cmp; |
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if ((cmp = comparator) == null) |
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siftDownComparable(0, x, es, n); |
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else |
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> |
siftDownUsingComparator(0, x, es, n, cmp); |
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> |
} |
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> |
} |
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return result; |
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} |
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|
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* position before i. This fact is used by iterator.remove so as to |
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* avoid missing traversing elements. |
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*/ |
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< |
@SuppressWarnings("unchecked") |
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< |
private E removeAt(int i) { |
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> |
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++; |
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int s = --size; |
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if (s == i) // removed last element |
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< |
queue[i] = null; |
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> |
es[i] = null; |
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else { |
610 |
< |
E moved = (E) queue[s]; |
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< |
queue[s] = null; |
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> |
E moved = (E) es[s]; |
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> |
es[s] = null; |
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siftDown(i, moved); |
613 |
< |
if (queue[i] == moved) { |
613 |
> |
if (es[i] == moved) { |
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siftUp(i, moved); |
615 |
< |
if (queue[i] != moved) |
615 |
> |
if (es[i] != moved) |
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return moved; |
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} |
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} |
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* promoting x up the tree until it is greater than or equal to |
625 |
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* its parent, or is the root. |
626 |
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* |
627 |
< |
* To simplify and speed up coercions and comparisons. the |
627 |
> |
* To simplify and speed up coercions and comparisons, the |
628 |
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* Comparable and Comparator versions are separated into different |
629 |
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* methods that are otherwise identical. (Similarly for siftDown.) |
630 |
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* |
633 |
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*/ |
634 |
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private void siftUp(int k, E x) { |
635 |
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if (comparator != null) |
636 |
< |
siftUpUsingComparator(k, x); |
636 |
> |
siftUpUsingComparator(k, x, queue, comparator); |
637 |
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else |
638 |
< |
siftUpComparable(k, x); |
638 |
> |
siftUpComparable(k, x, queue); |
639 |
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} |
640 |
|
|
641 |
< |
@SuppressWarnings("unchecked") |
642 |
< |
private void siftUpComparable(int k, E x) { |
639 |
< |
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 |
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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; |
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|
k = parent; |
650 |
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} |
651 |
< |
queue[k] = key; |
651 |
> |
es[k] = key; |
652 |
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} |
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 |
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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) |
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break; |
661 |
< |
queue[k] = e; |
661 |
> |
es[k] = e; |
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k = parent; |
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} |
664 |
< |
queue[k] = x; |
664 |
> |
es[k] = x; |
665 |
|
} |
666 |
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|
667 |
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/** |
674 |
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*/ |
675 |
|
private void siftDown(int k, E x) { |
676 |
|
if (comparator != null) |
677 |
< |
siftDownUsingComparator(k, x); |
677 |
> |
siftDownUsingComparator(k, x, queue, size, comparator); |
678 |
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else |
679 |
< |
siftDownComparable(k, x); |
679 |
> |
siftDownComparable(k, x, queue, size); |
680 |
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} |
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) |
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|
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]; |
708 |
< |
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 |
|
*/ |
720 |
– |
@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. |
745 |
– |
* @param s the stream |
746 |
– |
* @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. |
798 |
|
heapify(); |
799 |
|
} |
800 |
|
|
789 |
– |
public Spliterator<E> spliterator() { |
790 |
– |
return new PriorityQueueSpliterator<E>(this, 0, -1, 0); |
791 |
– |
} |
792 |
– |
|
801 |
|
/** |
802 |
< |
* This is very similar to ArrayList Spliterator, except for extra |
803 |
< |
* null checks. |
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. 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}. |
809 |
> |
* Overriding implementations should document the reporting of additional |
810 |
> |
* characteristic values. |
811 |
> |
* |
812 |
> |
* @return a {@code Spliterator} over the elements in this queue |
813 |
> |
* @since 1.8 |
814 |
|
*/ |
815 |
< |
static final class PriorityQueueSpliterator<E> implements Spliterator<E> { |
816 |
< |
private final PriorityQueue<E> pq; |
815 |
> |
public final Spliterator<E> spliterator() { |
816 |
> |
return new PriorityQueueSpliterator(0, -1, 0); |
817 |
> |
} |
818 |
> |
|
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, |
805 |
< |
int expectedModCount) { |
806 |
< |
this.pq = pq; |
824 |
> |
/** Creates new spliterator covering the given range. */ |
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 Spliterator<E> trySplit() { |
840 |
> |
public PriorityQueueSpliterator trySplit() { |
841 |
|
int hi = getFence(), lo = index, mid = (lo + hi) >>> 1; |
842 |
|
return (lo >= mid) ? null : |
843 |
< |
new PriorityQueueSpliterator<E>(pq, lo, index = mid, |
825 |
< |
expectedModCount); |
843 |
> |
new PriorityQueueSpliterator(lo, index = mid, expectedModCount); |
844 |
|
} |
845 |
|
|
828 |
– |
@SuppressWarnings("unchecked") |
846 |
|
public void forEachRemaining(Consumer<? super E> action) { |
830 |
– |
int i, hi, mc; // hoist accesses and checks from loop |
831 |
– |
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; |
841 |
< |
if ((i = index) >= 0 && (index = hi) <= a.length) { |
842 |
< |
for (E e;; ++i) { |
843 |
< |
if (i < hi) { |
844 |
< |
if ((e = (E) a[i]) == null) // must be CME |
845 |
< |
break; |
846 |
< |
action.accept(e); |
847 |
< |
} |
848 |
< |
else if (q.modCount != mc) |
849 |
< |
break; |
850 |
< |
else |
851 |
< |
return; |
852 |
< |
} |
853 |
< |
} |
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 |
< |
int hi = getFence(), lo = index; |
863 |
< |
if (lo >= 0 && lo < hi) { |
864 |
< |
index = lo + 1; |
865 |
< |
@SuppressWarnings("unchecked") E e = (E)pq.queue[lo]; |
866 |
< |
if (e == null) |
862 |
> |
if (action == null) |
863 |
> |
throw new NullPointerException(); |
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); |
866 |
– |
if (pq.modCount != expectedModCount) |
867 |
– |
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 |
|
} |