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Comparing jsr166/src/main/java/util/PriorityQueue.java (file contents):
Revision 1.63 by jsr166, Tue Mar 7 07:11:39 2006 UTC vs.
Revision 1.129 by jsr166, Mon Oct 1 00:10:53 2018 UTC

#	Line 1 | Line 1
1		/*
2	<	* %W% %E%
2	>	* Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
3	>	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4		*
5	<	* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
6	<	* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
5	>	* This code is free software; you can redistribute it and/or modify it
6	>	* under the terms of the GNU General Public License version 2 only, as
7	>	* published by the Free Software Foundation.  Oracle designates this
8	>	* particular file as subject to the "Classpath" exception as provided
9	>	* by Oracle in the LICENSE file that accompanied this code.
10	>	*
11	>	* This code is distributed in the hope that it will be useful, but WITHOUT
12	>	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13	>	* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14	>	* version 2 for more details (a copy is included in the LICENSE file that
15	>	* accompanied this code).
16	>	*
17	>	* You should have received a copy of the GNU General Public License version
18	>	* 2 along with this work; if not, write to the Free Software Foundation,
19	>	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20	>	*
21	>	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22	>	* or visit www.oracle.com if you need additional information or have any
23	>	* questions.
24		*/
25
26		package java.util;
27
28	+	import java.util.function.Consumer;
29	+	import java.util.function.Predicate;
30	+	import jdk.internal.misc.SharedSecrets;
31	+
32		/**
33		* An unbounded priority {@linkplain Queue queue} based on a priority heap.
34		* The elements of the priority queue are ordered according to their
#	Line 34 | Line 56 | package java.util;
56		* <p>This class and its iterator implement all of the
57		* <em>optional</em> methods of the {@link Collection} and {@link
58		* Iterator} interfaces.  The Iterator provided in method {@link
59	<	* #iterator()} is <em>not</em> guaranteed to traverse the elements of
59	>	* #iterator()} and the Spliterator provided in method {@link #spliterator()}
60	>	* are <em>not</em> guaranteed to traverse the elements of
61		* the priority queue in any particular order. If you need ordered
62		* traversal, consider using {@code Arrays.sort(pq.toArray())}.
63		*
64	<	* <p> <strong>Note that this implementation is not synchronized.</strong>
64	>	* <p><strong>Note that this implementation is not synchronized.</strong>
65		* Multiple threads should not access a {@code PriorityQueue}
66		* instance concurrently if any of the threads modifies the queue.
67		* Instead, use the thread-safe {@link
68		* java.util.concurrent.PriorityBlockingQueue} class.
69		*
70		* <p>Implementation note: this implementation provides
71	<	* O(log(n)) time for the enqueing and dequeing methods
71	>	* O(log(n)) time for the enqueuing and dequeuing methods
72		* ({@code offer}, {@code poll}, {@code remove()} and {@code add});
73		* linear time for the {@code remove(Object)} and {@code contains(Object)}
74		* methods; and constant time for the retrieval methods
75		* ({@code peek}, {@code element}, and {@code size}).
76		*
77		* <p>This class is a member of the
78	<	* <a href="{@docRoot}/../guide/collections/index.html">
78	>	* <a href="{@docRoot}/java.base/java/util/package-summary.html#CollectionsFramework">
79		* Java Collections Framework</a>.
80		*
81		* @since 1.5
59	–	* @version %I%, %G%
82		* @author Josh Bloch, Doug Lea
83	<	* @param <E> the type of elements held in this collection
83	>	* @param <E> the type of elements held in this queue
84		*/
85	+	@SuppressWarnings("unchecked")
86		public class PriorityQueue<E> extends AbstractQueue<E>
87		implements java.io.Serializable {
88
#	Line 75 | Line 98 | public class PriorityQueue<E> extends Ab
98		* heap and each descendant d of n, n <= d.  The element with the
99		* lowest value is in queue[0], assuming the queue is nonempty.
100		*/
101	<	private transient Object[] queue;
101	>	transient Object[] queue; // non-private to simplify nested class access
102
103		/**
104		* The number of elements in the priority queue.
105		*/
106	<	private int size = 0;
106	>	int size;
107
108		/**
109		* The comparator, or null if priority queue uses elements'
#	Line 92 | Line 115 | public class PriorityQueue<E> extends Ab
115		* The number of times this priority queue has been
116		* <i>structurally modified</i>.  See AbstractList for gory details.
117		*/
118	<	private transient int modCount = 0;
118	>	transient int modCount;     // non-private to simplify nested class access
119
120		/**
121		* Creates a {@code PriorityQueue} with the default initial
#	Line 117 | Line 140 | public class PriorityQueue<E> extends Ab
140		}
141
142		/**
143	+	* Creates a {@code PriorityQueue} with the default initial capacity and
144	+	* whose elements are ordered according to the specified comparator.
145	+	*
146	+	* @param  comparator the comparator that will be used to order this
147	+	*         priority queue.  If {@code null}, the {@linkplain Comparable
148	+	*         natural ordering} of the elements will be used.
149	+	* @since 1.8
150	+	*/
151	+	public PriorityQueue(Comparator<? super E> comparator) {
152	+	this(DEFAULT_INITIAL_CAPACITY, comparator);
153	+	}
154	+
155	+	/**
156		* Creates a {@code PriorityQueue} with the specified initial capacity
157		* that orders its elements according to the specified comparator.
158		*
#	Line 154 | Line 190 | public class PriorityQueue<E> extends Ab
190		*         of its elements are null
191		*/
192		public PriorityQueue(Collection<? extends E> c) {
193	<	initFromCollection(c);
194	<	if (c instanceof SortedSet)
195	<	comparator = (Comparator<? super E>)
196	<	((SortedSet<? extends E>)c).comparator();
197	<	else if (c instanceof PriorityQueue)
198	<	comparator = (Comparator<? super E>)
199	<	((PriorityQueue<? extends E>)c).comparator();
193	>	if (c instanceof SortedSet<?>) {
194	>	SortedSet<? extends E> ss = (SortedSet<? extends E>) c;
195	>	this.comparator = (Comparator<? super E>) ss.comparator();
196	>	initElementsFromCollection(ss);
197	>	}
198	>	else if (c instanceof PriorityQueue<?>) {
199	>	PriorityQueue<? extends E> pq = (PriorityQueue<? extends E>) c;
200	>	this.comparator = (Comparator<? super E>) pq.comparator();
201	>	initFromPriorityQueue(pq);
202	>	}
203		else {
204	<	comparator = null;
205	<	heapify();
204	>	this.comparator = null;
205	>	initFromCollection(c);
206		}
207		}
208
#	Line 182 | Line 221 | public class PriorityQueue<E> extends Ab
221		*         of its elements are null
222		*/
223		public PriorityQueue(PriorityQueue<? extends E> c) {
224	<	comparator = (Comparator<? super E>)c.comparator();
225	<	initFromCollection(c);
224	>	this.comparator = (Comparator<? super E>) c.comparator();
225	>	initFromPriorityQueue(c);
226		}
227
228		/**
#	Line 200 | Line 239 | public class PriorityQueue<E> extends Ab
239		*         of its elements are null
240		*/
241		public PriorityQueue(SortedSet<? extends E> c) {
242	<	comparator = (Comparator<? super E>)c.comparator();
243	<	initFromCollection(c);
242	>	this.comparator = (Comparator<? super E>) c.comparator();
243	>	initElementsFromCollection(c);
244	>	}
245	>
246	>	/** Ensures that queue[0] exists, helping peek() and poll(). */
247	>	private static Object[] ensureNonEmpty(Object[] es) {
248	>	return (es.length > 0) ? es : new Object[1];
249	>	}
250	>
251	>	private void initFromPriorityQueue(PriorityQueue<? extends E> c) {
252	>	if (c.getClass() == PriorityQueue.class) {
253	>	this.queue = ensureNonEmpty(c.toArray());
254	>	this.size = c.size();
255	>	} else {
256	>	initFromCollection(c);
257	>	}
258	>	}
259	>
260	>	private void initElementsFromCollection(Collection<? extends E> c) {
261	>	Object[] es = c.toArray();
262	>	int len = es.length;
263	>	// If c.toArray incorrectly doesn't return Object[], copy it.
264	>	if (es.getClass() != Object[].class)
265	>	es = Arrays.copyOf(es, len, Object[].class);
266	>	if (len == 1 || this.comparator != null)
267	>	for (Object e : es)
268	>	if (e == null)
269	>	throw new NullPointerException();
270	>	this.queue = ensureNonEmpty(es);
271	>	this.size = len;
272		}
273
274		/**
#	Line 210 | Line 277 | public class PriorityQueue<E> extends Ab
277		* @param c the collection
278		*/
279		private void initFromCollection(Collection<? extends E> c) {
280	<	Object[] a = c.toArray();
281	<	// If c.toArray incorrectly doesn't return Object[], copy it.
215	<	if (a.getClass() != Object[].class)
216	<	a = Arrays.copyOf(a, a.length, Object[].class);
217	<	queue = a;
218	<	size = a.length;
280	>	initElementsFromCollection(c);
281	>	heapify();
282		}
283
284		/**
285	+	* The maximum size of array to allocate.
286	+	* Some VMs reserve some header words in an array.
287	+	* Attempts to allocate larger arrays may result in
288	+	* OutOfMemoryError: Requested array size exceeds VM limit
289	+	*/
290	+	private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
291	+
292	+	/**
293		* Increases the capacity of the array.
294		*
295		* @param minCapacity the desired minimum capacity
296		*/
297		private void grow(int minCapacity) {
298	<	if (minCapacity < 0) // overflow
228	<	throw new OutOfMemoryError();
229	<	int oldCapacity = queue.length;
298	>	int oldCapacity = queue.length;
299		// Double size if small; else grow by 50%
300	<	int newCapacity = ((oldCapacity < 64)?
301	<	((oldCapacity + 1) * 2):
302	<	((oldCapacity / 2) * 3));
303	<	if (newCapacity < 0) // overflow
304	<	newCapacity = Integer.MAX_VALUE;
305	<	if (newCapacity < minCapacity)
237	<	newCapacity = minCapacity;
300	>	int newCapacity = oldCapacity + ((oldCapacity < 64) ?
301	>	(oldCapacity + 2) :
302	>	(oldCapacity >> 1));
303	>	// overflow-conscious code
304	>	if (newCapacity - MAX_ARRAY_SIZE > 0)
305	>	newCapacity = hugeCapacity(minCapacity);
306		queue = Arrays.copyOf(queue, newCapacity);
307		}
308
309	+	private static int hugeCapacity(int minCapacity) {
310	+	if (minCapacity < 0) // overflow
311	+	throw new OutOfMemoryError();
312	+	return (minCapacity > MAX_ARRAY_SIZE) ?
313	+	Integer.MAX_VALUE :
314	+	MAX_ARRAY_SIZE;
315	+	}
316	+
317		/**
318		* Inserts the specified element into this priority queue.
319		*
#	Line 267 | Line 343 | public class PriorityQueue<E> extends Ab
343		int i = size;
344		if (i >= queue.length)
345		grow(i + 1);
346	+	siftUp(i, e);
347		size = i + 1;
271	–	if (i == 0)
272	–	queue[0] = e;
273	–	else
274	–	siftUp(i, e);
348		return true;
349		}
350
351		public E peek() {
279	–	if (size == 0)
280	–	return null;
352		return (E) queue[0];
353		}
354
355		private int indexOf(Object o) {
356	<	if (o != null) {
357	<	for (int i = 0; i < size; i++)
358	<	if (o.equals(queue[i]))
356	>	if (o != null) {
357	>	final Object[] es = queue;
358	>	for (int i = 0, n = size; i < n; i++)
359	>	if (o.equals(es[i]))
360		return i;
361		}
362		return -1;
#	Line 302 | Line 374 | public class PriorityQueue<E> extends Ab
374		* @return {@code true} if this queue changed as a result of the call
375		*/
376		public boolean remove(Object o) {
377	<	int i = indexOf(o);
378	<	if (i == -1)
379	<	return false;
380	<	else {
381	<	removeAt(i);
382	<	return true;
383	<	}
377	>	int i = indexOf(o);
378	>	if (i == -1)
379	>	return false;
380	>	else {
381	>	removeAt(i);
382	>	return true;
383	>	}
384		}
385
386		/**
387	<	* Version of remove using reference equality, not equals.
316	<	* Needed by iterator.remove.
387	>	* Identity-based version for use in Itr.remove.
388		*
389		* @param o element to be removed from this queue, if present
319	–	* @return {@code true} if removed
390		*/
391	<	boolean removeEq(Object o) {
392	<	for (int i = 0; i < size; i++) {
393	<	if (o == queue[i]) {
391	>	void removeEq(Object o) {
392	>	final Object[] es = queue;
393	>	for (int i = 0, n = size; i < n; i++) {
394	>	if (o == es[i]) {
395		removeAt(i);
396	<	return true;
396	>	break;
397		}
398		}
328	–	return false;
399		}
400
401		/**
#	Line 337 | Line 407 | public class PriorityQueue<E> extends Ab
407		* @return {@code true} if this queue contains the specified element
408		*/
409		public boolean contains(Object o) {
410	<	return indexOf(o) != -1;
410	>	return indexOf(o) >= 0;
411		}
412
413		/**
#	Line 375 | Line 445 | public class PriorityQueue<E> extends Ab
445		* precise control over the runtime type of the output array, and may,
446		* under certain circumstances, be used to save allocation costs.
447		*
448	<	* <p>Suppose <tt>x</tt> is a queue known to contain only strings.
448	>	* <p>Suppose {@code x} is a queue known to contain only strings.
449		* The following code can be used to dump the queue into a newly
450	<	* allocated array of <tt>String</tt>:
450	>	* allocated array of {@code String}:
451		*
452	<	* <pre>
383	<	*     String[] y = x.toArray(new String[0]);</pre>
452	>	* <pre> {@code String[] y = x.toArray(new String[0]);}</pre>
453		*
454	<	* Note that <tt>toArray(new Object[0])</tt> is identical in function to
455	<	* <tt>toArray()</tt>.
454	>	* Note that {@code toArray(new Object[0])} is identical in function to
455	>	* {@code toArray()}.
456		*
457		* @param a the array into which the elements of the queue are to
458		*          be stored, if it is big enough; otherwise, a new array of the
#	Line 395 | Line 464 | public class PriorityQueue<E> extends Ab
464		* @throws NullPointerException if the specified array is null
465		*/
466		public <T> T[] toArray(T[] a) {
467	+	final int size = this.size;
468		if (a.length < size)
469		// Make a new array of a's runtime type, but my contents:
470		return (T[]) Arrays.copyOf(queue, size, a.getClass());
471	<	System.arraycopy(queue, 0, a, 0, size);
471	>	System.arraycopy(queue, 0, a, 0, size);
472		if (a.length > size)
473		a[size] = null;
474		return a;
#	Line 419 | Line 489 | public class PriorityQueue<E> extends Ab
489		* Index (into queue array) of element to be returned by
490		* subsequent call to next.
491		*/
492	<	private int cursor = 0;
492	>	private int cursor;
493
494		/**
495		* Index of element returned by most recent call to next,
#	Line 439 | Line 509 | public class PriorityQueue<E> extends Ab
509		* We expect that most iterations, even those involving removals,
510		* will not need to store elements in this field.
511		*/
512	<	private ArrayDeque<E> forgetMeNot = null;
512	>	private ArrayDeque<E> forgetMeNot;
513
514		/**
515		* Element returned by the most recent call to next iff that
516		* element was drawn from the forgetMeNot list.
517		*/
518	<	private E lastRetElt = null;
518	>	private E lastRetElt;
519
520		/**
521		* The modCount value that the iterator believes that the backing
#	Line 454 | Line 524 | public class PriorityQueue<E> extends Ab
524		*/
525		private int expectedModCount = modCount;
526
527	+	Itr() {}                        // prevent access constructor creation
528	+
529		public boolean hasNext() {
530		return cursor < size ||
531		(forgetMeNot != null && !forgetMeNot.isEmpty());
#	Line 483 | Line 555 | public class PriorityQueue<E> extends Ab
555		cursor--;
556		else {
557		if (forgetMeNot == null)
558	<	forgetMeNot = new ArrayDeque<E>();
558	>	forgetMeNot = new ArrayDeque<>();
559		forgetMeNot.add(moved);
560		}
561		} else if (lastRetElt != null) {
#	Line 491 | Line 563 | public class PriorityQueue<E> extends Ab
563		lastRetElt = null;
564		} else {
565		throw new IllegalStateException();
566	<	}
566	>	}
567		expectedModCount = modCount;
568		}
569		}
#	Line 506 | Line 578 | public class PriorityQueue<E> extends Ab
578		*/
579		public void clear() {
580		modCount++;
581	<	for (int i = 0; i < size; i++)
582	<	queue[i] = null;
581	>	final Object[] es = queue;
582	>	for (int i = 0, n = size; i < n; i++)
583	>	es[i] = null;
584		size = 0;
585		}
586
587		public E poll() {
588	<	if (size == 0)
589	<	return null;
590	<	int s = --size;
591	<	modCount++;
592	<	E result = (E) queue[0];
593	<	E x = (E) queue[s];
594	<	queue[s] = null;
595	<	if (s != 0)
596	<	siftDown(0, x);
588	>	final Object[] es;
589	>	final E result;
590	>
591	>	if ((result = (E) ((es = queue)[0])) != null) {
592	>	modCount++;
593	>	final int n;
594	>	final E x = (E) es[(n = --size)];
595	>	es[n] = null;
596	>	if (n > 0) {
597	>	final Comparator<? super E> cmp;
598	>	if ((cmp = comparator) == null)
599	>	siftDownComparable(0, x, es, n);
600	>	else
601	>	siftDownUsingComparator(0, x, es, n, cmp);
602	>	}
603	>	}
604		return result;
605		}
606
#	Line 536 | Line 616 | public class PriorityQueue<E> extends Ab
616		* position before i. This fact is used by iterator.remove so as to
617		* avoid missing traversing elements.
618		*/
619	<	private E removeAt(int i) {
620	<	assert i >= 0 && i < size;
619	>	E removeAt(int i) {
620	>	// assert i >= 0 && i < size;
621	>	final Object[] es = queue;
622		modCount++;
623		int s = --size;
624		if (s == i) // removed last element
625	<	queue[i] = null;
625	>	es[i] = null;
626		else {
627	<	E moved = (E) queue[s];
628	<	queue[s] = null;
627	>	E moved = (E) es[s];
628	>	es[s] = null;
629		siftDown(i, moved);
630	<	if (queue[i] == moved) {
630	>	if (es[i] == moved) {
631		siftUp(i, moved);
632	<	if (queue[i] != moved)
632	>	if (es[i] != moved)
633		return moved;
634		}
635		}
#	Line 560 | Line 641 | public class PriorityQueue<E> extends Ab
641		* promoting x up the tree until it is greater than or equal to
642		* its parent, or is the root.
643		*
644	<	* To simplify and speed up coercions and comparisons. the
644	>	* To simplify and speed up coercions and comparisons, the
645		* Comparable and Comparator versions are separated into different
646		* methods that are otherwise identical. (Similarly for siftDown.)
647		*
#	Line 569 | Line 650 | public class PriorityQueue<E> extends Ab
650		*/
651		private void siftUp(int k, E x) {
652		if (comparator != null)
653	<	siftUpUsingComparator(k, x);
653	>	siftUpUsingComparator(k, x, queue, comparator);
654		else
655	<	siftUpComparable(k, x);
655	>	siftUpComparable(k, x, queue);
656		}
657
658	<	private void siftUpComparable(int k, E x) {
659	<	Comparable<? super E> key = (Comparable<? super E>) x;
658	>	private static <T> void siftUpComparable(int k, T x, Object[] es) {
659	>	Comparable<? super T> key = (Comparable<? super T>) x;
660		while (k > 0) {
661		int parent = (k - 1) >>> 1;
662	<	Object e = queue[parent];
663	<	if (key.compareTo((E) e) >= 0)
662	>	Object e = es[parent];
663	>	if (key.compareTo((T) e) >= 0)
664		break;
665	<	queue[k] = e;
665	>	es[k] = e;
666		k = parent;
667		}
668	<	queue[k] = key;
668	>	es[k] = key;
669		}
670
671	<	private void siftUpUsingComparator(int k, E x) {
671	>	private static <T> void siftUpUsingComparator(
672	>	int k, T x, Object[] es, Comparator<? super T> cmp) {
673		while (k > 0) {
674		int parent = (k - 1) >>> 1;
675	<	Object e = queue[parent];
676	<	if (comparator.compare(x, (E) e) >= 0)
675	>	Object e = es[parent];
676	>	if (cmp.compare(x, (T) e) >= 0)
677		break;
678	<	queue[k] = e;
678	>	es[k] = e;
679		k = parent;
680		}
681	<	queue[k] = x;
681	>	es[k] = x;
682		}
683
684		/**
#	Line 609 | Line 691 | public class PriorityQueue<E> extends Ab
691		*/
692		private void siftDown(int k, E x) {
693		if (comparator != null)
694	<	siftDownUsingComparator(k, x);
694	>	siftDownUsingComparator(k, x, queue, size, comparator);
695		else
696	<	siftDownComparable(k, x);
696	>	siftDownComparable(k, x, queue, size);
697		}
698
699	<	private void siftDownComparable(int k, E x) {
700	<	Comparable<? super E> key = (Comparable<? super E>)x;
701	<	int half = size >>> 1;        // loop while a non-leaf
699	>	private static <T> void siftDownComparable(int k, T x, Object[] es, int n) {
700	>	// assert n > 0;
701	>	Comparable<? super T> key = (Comparable<? super T>)x;
702	>	int half = n >>> 1;           // loop while a non-leaf
703		while (k < half) {
704		int child = (k << 1) + 1; // assume left child is least
705	<	Object c = queue[child];
705	>	Object c = es[child];
706		int right = child + 1;
707	<	if (right < size &&
708	<	((Comparable<? super E>) c).compareTo((E) queue[right]) > 0)
709	<	c = queue[child = right];
710	<	if (key.compareTo((E) c) <= 0)
707	>	if (right < n &&
708	>	((Comparable<? super T>) c).compareTo((T) es[right]) > 0)
709	>	c = es[child = right];
710	>	if (key.compareTo((T) c) <= 0)
711		break;
712	<	queue[k] = c;
712	>	es[k] = c;
713		k = child;
714		}
715	<	queue[k] = key;
715	>	es[k] = key;
716		}
717
718	<	private void siftDownUsingComparator(int k, E x) {
719	<	int half = size >>> 1;
718	>	private static <T> void siftDownUsingComparator(
719	>	int k, T x, Object[] es, int n, Comparator<? super T> cmp) {
720	>	// assert n > 0;
721	>	int half = n >>> 1;
722		while (k < half) {
723		int child = (k << 1) + 1;
724	<	Object c = queue[child];
724	>	Object c = es[child];
725		int right = child + 1;
726	<	if (right < size &&
727	<	comparator.compare((E) c, (E) queue[right]) > 0)
728	<	c = queue[child = right];
644	<	if (comparator.compare(x, (E) c) <= 0)
726	>	if (right < n && cmp.compare((T) c, (T) es[right]) > 0)
727	>	c = es[child = right];
728	>	if (cmp.compare(x, (T) c) <= 0)
729		break;
730	<	queue[k] = c;
730	>	es[k] = c;
731		k = child;
732		}
733	<	queue[k] = x;
733	>	es[k] = x;
734		}
735
736		/**
737		* Establishes the heap invariant (described above) in the entire tree,
738		* assuming nothing about the order of the elements prior to the call.
739	+	* This classic algorithm due to Floyd (1964) is known to be O(size).
740		*/
741		private void heapify() {
742	<	for (int i = (size >>> 1) - 1; i >= 0; i--)
743	<	siftDown(i, (E) queue[i]);
742	>	final Object[] es = queue;
743	>	int n = size, i = (n >>> 1) - 1;
744	>	final Comparator<? super E> cmp;
745	>	if ((cmp = comparator) == null)
746	>	for (; i >= 0; i--)
747	>	siftDownComparable(i, (E) es[i], es, n);
748	>	else
749	>	for (; i >= 0; i--)
750	>	siftDownUsingComparator(i, (E) es[i], es, n, cmp);
751		}
752
753		/**
#	Line 672 | Line 764 | public class PriorityQueue<E> extends Ab
764		}
765
766		/**
767	<	* Saves the state of the instance to a stream (that
676	<	* is, serializes it).
767	>	* Saves this queue to a stream (that is, serializes it).
768		*
769	+	* @param s the stream
770	+	* @throws java.io.IOException if an I/O error occurs
771		* @serialData The length of the array backing the instance is
772		*             emitted (int), followed by all of its elements
773		*             (each an {@code Object}) in the proper order.
681	–	* @param s the stream
774		*/
775		private void writeObject(java.io.ObjectOutputStream s)
776	<	throws java.io.IOException{
776	>	throws java.io.IOException {
777		// Write out element count, and any hidden stuff
778		s.defaultWriteObject();
779
780		// Write out array length, for compatibility with 1.5 version
781		s.writeInt(Math.max(2, size + 1));
782
783	<	// Write out all elements in the proper order.
784	<	for (int i = 0; i < size; i++)
785	<	s.writeObject(queue[i]);
783	>	// Write out all elements in the "proper order".
784	>	final Object[] es = queue;
785	>	for (int i = 0, n = size; i < n; i++)
786	>	s.writeObject(es[i]);
787		}
788
789		/**
#	Line 698 | Line 791 | public class PriorityQueue<E> extends Ab
791		* (that is, deserializes it).
792		*
793		* @param s the stream
794	+	* @throws ClassNotFoundException if the class of a serialized object
795	+	*         could not be found
796	+	* @throws java.io.IOException if an I/O error occurs
797		*/
798		private void readObject(java.io.ObjectInputStream s)
799		throws java.io.IOException, ClassNotFoundException {
#	Line 707 | Line 803 | public class PriorityQueue<E> extends Ab
803		// Read in (and discard) array length
804		s.readInt();
805
806	<	queue = new Object[size];
806	>	SharedSecrets.getJavaObjectInputStreamAccess().checkArray(s, Object[].class, size);
807	>	final Object[] es = queue = new Object[Math.max(size, 1)];
808	>
809	>	// Read in all elements.
810	>	for (int i = 0, n = size; i < n; i++)
811	>	es[i] = s.readObject();
812	>
813	>	// Elements are guaranteed to be in "proper order", but the
814	>	// spec has never explained what that might be.
815	>	heapify();
816	>	}
817	>
818	>	/**
819	>	* Creates a <em><a href="Spliterator.html#binding">late-binding</a></em>
820	>	* and <em>fail-fast</em> {@link Spliterator} over the elements in this
821	>	* queue. The spliterator does not traverse elements in any particular order
822	>	* (the {@link Spliterator#ORDERED ORDERED} characteristic is not reported).
823	>	*
824	>	* <p>The {@code Spliterator} reports {@link Spliterator#SIZED},
825	>	* {@link Spliterator#SUBSIZED}, and {@link Spliterator#NONNULL}.
826	>	* Overriding implementations should document the reporting of additional
827	>	* characteristic values.
828	>	*
829	>	* @return a {@code Spliterator} over the elements in this queue
830	>	* @since 1.8
831	>	*/
832	>	public final Spliterator<E> spliterator() {
833	>	return new PriorityQueueSpliterator(0, -1, 0);
834	>	}
835	>
836	>	final class PriorityQueueSpliterator implements Spliterator<E> {
837	>	private int index;            // current index, modified on advance/split
838	>	private int fence;            // -1 until first use
839	>	private int expectedModCount; // initialized when fence set
840	>
841	>	/** Creates new spliterator covering the given range. */
842	>	PriorityQueueSpliterator(int origin, int fence, int expectedModCount) {
843	>	this.index = origin;
844	>	this.fence = fence;
845	>	this.expectedModCount = expectedModCount;
846	>	}
847	>
848	>	private int getFence() { // initialize fence to size on first use
849	>	int hi;
850	>	if ((hi = fence) < 0) {
851	>	expectedModCount = modCount;
852	>	hi = fence = size;
853	>	}
854	>	return hi;
855	>	}
856	>
857	>	public PriorityQueueSpliterator trySplit() {
858	>	int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
859	>	return (lo >= mid) ? null :
860	>	new PriorityQueueSpliterator(lo, index = mid, expectedModCount);
861	>	}
862	>
863	>	public void forEachRemaining(Consumer<? super E> action) {
864	>	if (action == null)
865	>	throw new NullPointerException();
866	>	if (fence < 0) { fence = size; expectedModCount = modCount; }
867	>	final Object[] es = queue;
868	>	int i, hi; E e;
869	>	for (i = index, index = hi = fence; i < hi; i++) {
870	>	if ((e = (E) es[i]) == null)
871	>	break;      // must be CME
872	>	action.accept(e);
873	>	}
874	>	if (modCount != expectedModCount)
875	>	throw new ConcurrentModificationException();
876	>	}
877	>
878	>	public boolean tryAdvance(Consumer<? super E> action) {
879	>	if (action == null)
880	>	throw new NullPointerException();
881	>	if (fence < 0) { fence = size; expectedModCount = modCount; }
882	>	int i;
883	>	if ((i = index) < fence) {
884	>	index = i + 1;
885	>	E e;
886	>	if ((e = (E) queue[i]) == null
887	>	|| modCount != expectedModCount)
888	>	throw new ConcurrentModificationException();
889	>	action.accept(e);
890	>	return true;
891	>	}
892	>	return false;
893	>	}
894	>
895	>	public long estimateSize() {
896	>	return getFence() - index;
897	>	}
898	>
899	>	public int characteristics() {
900	>	return Spliterator.SIZED | Spliterator.SUBSIZED | Spliterator.NONNULL;
901	>	}
902	>	}
903
904	<	// Read in all elements in the proper order.
905	<	for (int i = 0; i < size; i++)
906	<	queue[i] = s.readObject();
904	>	/**
905	>	* @throws NullPointerException {@inheritDoc}
906	>	*/
907	>	public boolean removeIf(Predicate<? super E> filter) {
908	>	Objects.requireNonNull(filter);
909	>	return bulkRemove(filter);
910	>	}
911	>
912	>	/**
913	>	* @throws NullPointerException {@inheritDoc}
914	>	*/
915	>	public boolean removeAll(Collection<?> c) {
916	>	Objects.requireNonNull(c);
917	>	return bulkRemove(e -> c.contains(e));
918	>	}
919	>
920	>	/**
921	>	* @throws NullPointerException {@inheritDoc}
922	>	*/
923	>	public boolean retainAll(Collection<?> c) {
924	>	Objects.requireNonNull(c);
925	>	return bulkRemove(e -> !c.contains(e));
926	>	}
927	>
928	>	// A tiny bit set implementation
929	>
930	>	private static long[] nBits(int n) {
931	>	return new long[((n - 1) >> 6) + 1];
932	>	}
933	>	private static void setBit(long[] bits, int i) {
934	>	bits[i >> 6] |= 1L << i;
935	>	}
936	>	private static boolean isClear(long[] bits, int i) {
937	>	return (bits[i >> 6] & (1L << i)) == 0;
938	>	}
939	>
940	>	/** Implementation of bulk remove methods. */
941	>	private boolean bulkRemove(Predicate<? super E> filter) {
942	>	final int expectedModCount = ++modCount;
943	>	final Object[] es = queue;
944	>	final int end = size;
945	>	int i;
946	>	// Optimize for initial run of survivors
947	>	for (i = 0; i < end && !filter.test((E) es[i]); i++)
948	>	;
949	>	if (i >= end) {
950	>	if (modCount != expectedModCount)
951	>	throw new ConcurrentModificationException();
952	>	return false;
953	>	}
954	>	// Tolerate predicates that reentrantly access the collection for
955	>	// read (but writers still get CME), so traverse once to find
956	>	// elements to delete, a second pass to physically expunge.
957	>	final int beg = i;
958	>	final long[] deathRow = nBits(end - beg);
959	>	deathRow[0] = 1L;   // set bit 0
960	>	for (i = beg + 1; i < end; i++)
961	>	if (filter.test((E) es[i]))
962	>	setBit(deathRow, i - beg);
963	>	if (modCount != expectedModCount)
964	>	throw new ConcurrentModificationException();
965	>	int w = beg;
966	>	for (i = beg; i < end; i++)
967	>	if (isClear(deathRow, i - beg))
968	>	es[w++] = es[i];
969	>	for (i = size = w; i < end; i++)
970	>	es[i] = null;
971	>	heapify();
972	>	return true;
973	>	}
974	>
975	>	/**
976	>	* @throws NullPointerException {@inheritDoc}
977	>	*/
978	>	public void forEach(Consumer<? super E> action) {
979	>	Objects.requireNonNull(action);
980	>	final int expectedModCount = modCount;
981	>	final Object[] es = queue;
982	>	for (int i = 0, n = size; i < n; i++)
983	>	action.accept((E) es[i]);
984	>	if (expectedModCount != modCount)
985	>	throw new ConcurrentModificationException();
986		}
987		}

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