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Comparing jsr166/src/main/java/util/PriorityQueue.java (file contents):
Revision 1.80 by jsr166, Wed Jan 16 01:59:47 2013 UTC vs.
Revision 1.108 by jsr166, Sun Oct 11 00:50:06 2015 UTC

#	Line 1 | Line 1
1		/*
2	<	* Copyright (c) 2003, 2006, Oracle and/or its affiliates. All rights reserved.
2	>	* Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
3		* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4		*
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.  Sun designates this
7	>	* published by the Free Software Foundation.  Oracle designates this
8		* particular file as subject to the "Classpath" exception as provided
9	<	* by Sun in the LICENSE file that accompanied this code.
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
#	Line 25 | Line 25
25
26		package java.util;
27
28	+	import java.util.function.Consumer;
29	+
30		/**
31		* An unbounded priority {@linkplain Queue queue} based on a priority heap.
32		* The elements of the priority queue are ordered according to their
#	Line 75 | Line 77 | package java.util;
77		*
78		* @since 1.5
79		* @author Josh Bloch, Doug Lea
80	<	* @param <E> the type of elements held in this collection
80	>	* @param <E> the type of elements held in this queue
81		*/
80	–	@SuppressWarnings("unchecked")
82		public class PriorityQueue<E> extends AbstractQueue<E>
83		implements java.io.Serializable {
84
#	Line 93 | Line 94 | public class PriorityQueue<E> extends Ab
94		* heap and each descendant d of n, n <= d.  The element with the
95		* lowest value is in queue[0], assuming the queue is nonempty.
96		*/
97	<	private transient Object[] queue;
97	>	transient Object[] queue; // non-private to simplify nested class access
98
99		/**
100		* The number of elements in the priority queue.
101		*/
102	<	private int size = 0;
102	>	int size;
103
104		/**
105		* The comparator, or null if priority queue uses elements'
#	Line 110 | Line 111 | public class PriorityQueue<E> extends Ab
111		* The number of times this priority queue has been
112		* <i>structurally modified</i>.  See AbstractList for gory details.
113		*/
114	<	private transient int modCount = 0;
114	>	transient int modCount;     // non-private to simplify nested class access
115
116		/**
117		* Creates a {@code PriorityQueue} with the default initial
#	Line 135 | Line 136 | public class PriorityQueue<E> extends Ab
136		}
137
138		/**
139	+	* Creates a {@code PriorityQueue} with the default initial capacity and
140	+	* whose elements are ordered according to the specified comparator.
141	+	*
142	+	* @param  comparator the comparator that will be used to order this
143	+	*         priority queue.  If {@code null}, the {@linkplain Comparable
144	+	*         natural ordering} of the elements will be used.
145	+	* @since 1.8
146	+	*/
147	+	public PriorityQueue(Comparator<? super E> comparator) {
148	+	this(DEFAULT_INITIAL_CAPACITY, comparator);
149	+	}
150	+
151	+	/**
152		* Creates a {@code PriorityQueue} with the specified initial capacity
153		* that orders its elements according to the specified comparator.
154		*
#	Line 244 | Line 258 | public class PriorityQueue<E> extends Ab
258		a = Arrays.copyOf(a, a.length, Object[].class);
259		int len = a.length;
260		if (len == 1 || this.comparator != null)
261	<	for (int i = 0; i < len; i++)
262	<	if (a[i] == null)
261	>	for (Object e : a)
262	>	if (e == null)
263		throw new NullPointerException();
264		this.queue = a;
265		this.size = a.length;
#	Line 331 | Line 345 | public class PriorityQueue<E> extends Ab
345		return true;
346		}
347
348	+	@SuppressWarnings("unchecked")
349		public E peek() {
350		return (size == 0) ? null : (E) queue[0];
351		}
#	Line 391 | Line 406 | public class PriorityQueue<E> extends Ab
406		* @return {@code true} if this queue contains the specified element
407		*/
408		public boolean contains(Object o) {
409	<	return indexOf(o) != -1;
409	>	return indexOf(o) >= 0;
410		}
411
412		/**
#	Line 433 | Line 448 | public class PriorityQueue<E> extends Ab
448		* The following code can be used to dump the queue into a newly
449		* allocated array of {@code String}:
450		*
451	<	*  <pre> {@code String[] y = x.toArray(new String[0]);}</pre>
451	>	* <pre> {@code String[] y = x.toArray(new String[0]);}</pre>
452		*
453		* Note that {@code toArray(new Object[0])} is identical in function to
454		* {@code toArray()}.
#	Line 447 | Line 462 | public class PriorityQueue<E> extends Ab
462		*         this queue
463		* @throws NullPointerException if the specified array is null
464		*/
465	+	@SuppressWarnings("unchecked")
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());
#	Line 472 | 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 492 | 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 512 | Line 529 | public class PriorityQueue<E> extends Ab
529		(forgetMeNot != null && !forgetMeNot.isEmpty());
530		}
531
532	+	@SuppressWarnings("unchecked")
533		public E next() {
534		if (expectedModCount != modCount)
535		throw new ConcurrentModificationException();
#	Line 536 | Line 554 | public class PriorityQueue<E> extends Ab
554		cursor--;
555		else {
556		if (forgetMeNot == null)
557	<	forgetMeNot = new ArrayDeque<E>();
557	>	forgetMeNot = new ArrayDeque<>();
558		forgetMeNot.add(moved);
559		}
560		} else if (lastRetElt != null) {
#	Line 564 | Line 582 | public class PriorityQueue<E> extends Ab
582		size = 0;
583		}
584
585	+	@SuppressWarnings("unchecked")
586		public E poll() {
587		if (size == 0)
588		return null;
#	Line 589 | Line 608 | public class PriorityQueue<E> extends Ab
608		* position before i. This fact is used by iterator.remove so as to
609		* avoid missing traversing elements.
610		*/
611	<	private E removeAt(int i) {
611	>	@SuppressWarnings("unchecked")
612	>	E removeAt(int i) {
613		// assert i >= 0 && i < size;
614		modCount++;
615		int s = --size;
#	Line 627 | Line 647 | public class PriorityQueue<E> extends Ab
647		siftUpComparable(k, x);
648		}
649
650	+	@SuppressWarnings("unchecked")
651		private void siftUpComparable(int k, E x) {
652		Comparable<? super E> key = (Comparable<? super E>) x;
653		while (k > 0) {
#	Line 640 | Line 661 | public class PriorityQueue<E> extends Ab
661		queue[k] = key;
662		}
663
664	+	@SuppressWarnings("unchecked")
665		private void siftUpUsingComparator(int k, E x) {
666		while (k > 0) {
667		int parent = (k - 1) >>> 1;
#	Line 667 | Line 689 | public class PriorityQueue<E> extends Ab
689		siftDownComparable(k, x);
690		}
691
692	+	@SuppressWarnings("unchecked")
693		private void siftDownComparable(int k, E x) {
694		Comparable<? super E> key = (Comparable<? super E>)x;
695		int half = size >>> 1;        // loop while a non-leaf
#	Line 685 | Line 708 | public class PriorityQueue<E> extends Ab
708		queue[k] = key;
709		}
710
711	+	@SuppressWarnings("unchecked")
712		private void siftDownUsingComparator(int k, E x) {
713		int half = size >>> 1;
714		while (k < half) {
#	Line 706 | Line 730 | public class PriorityQueue<E> extends Ab
730		* Establishes the heap invariant (described above) in the entire tree,
731		* assuming nothing about the order of the elements prior to the call.
732		*/
733	+	@SuppressWarnings("unchecked")
734		private void heapify() {
735		for (int i = (size >>> 1) - 1; i >= 0; i--)
736		siftDown(i, (E) queue[i]);
#	Line 730 | Line 755 | public class PriorityQueue<E> extends Ab
755		* @serialData The length of the array backing the instance is
756		*             emitted (int), followed by all of its elements
757		*             (each an {@code Object}) in the proper order.
758	+	* @param s the stream
759	+	* @throws java.io.IOException if an I/O error occurs
760		*/
761		private void writeObject(java.io.ObjectOutputStream s)
762		throws java.io.IOException {
#	Line 745 | Line 772 | public class PriorityQueue<E> extends Ab
772		}
773
774		/**
775	<	* Reconstitutes this queue from a stream (that is, deserializes it).
775	>	* Reconstitutes the {@code PriorityQueue} instance from a stream
776	>	* (that is, deserializes it).
777	>	*
778	>	* @param s the stream
779	>	* @throws ClassNotFoundException if the class of a serialized object
780	>	*         could not be found
781	>	* @throws java.io.IOException if an I/O error occurs
782		*/
783		private void readObject(java.io.ObjectInputStream s)
784		throws java.io.IOException, ClassNotFoundException {
#	Line 765 | Line 798 | public class PriorityQueue<E> extends Ab
798		// spec has never explained what that might be.
799		heapify();
800		}
801	+
802	+	/**
803	+	* Creates a <em><a href="Spliterator.html#binding">late-binding</a></em>
804	+	* and <em>fail-fast</em> {@link Spliterator} over the elements in this
805	+	* queue.
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	+	public final Spliterator<E> spliterator() {
816	+	return new PriorityQueueSpliterator<>(this, 0, -1, 0);
817	+	}
818	+
819	+	static final class PriorityQueueSpliterator<E> implements Spliterator<E> {
820	+	/*
821	+	* This is very similar to ArrayList Spliterator, except for
822	+	* extra null checks.
823	+	*/
824	+	private final PriorityQueue<E> pq;
825	+	private int index;            // current index, modified on advance/split
826	+	private int fence;            // -1 until first use
827	+	private int expectedModCount; // initialized when fence set
828	+
829	+	/** Creates new spliterator covering the given range. */
830	+	PriorityQueueSpliterator(PriorityQueue<E> pq, int origin, int fence,
831	+	int expectedModCount) {
832	+	this.pq = pq;
833	+	this.index = origin;
834	+	this.fence = fence;
835	+	this.expectedModCount = expectedModCount;
836	+	}
837	+
838	+	private int getFence() { // initialize fence to size on first use
839	+	int hi;
840	+	if ((hi = fence) < 0) {
841	+	expectedModCount = pq.modCount;
842	+	hi = fence = pq.size;
843	+	}
844	+	return hi;
845	+	}
846	+
847	+	public PriorityQueueSpliterator<E> trySplit() {
848	+	int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
849	+	return (lo >= mid) ? null :
850	+	new PriorityQueueSpliterator<>(pq, lo, index = mid,
851	+	expectedModCount);
852	+	}
853	+
854	+	@SuppressWarnings("unchecked")
855	+	public void forEachRemaining(Consumer<? super E> action) {
856	+	int i, hi, mc; // hoist accesses and checks from loop
857	+	PriorityQueue<E> q; Object[] a;
858	+	if (action == null)
859	+	throw new NullPointerException();
860	+	if ((q = pq) != null && (a = q.queue) != null) {
861	+	if ((hi = fence) < 0) {
862	+	mc = q.modCount;
863	+	hi = q.size;
864	+	}
865	+	else
866	+	mc = expectedModCount;
867	+	if ((i = index) >= 0 && (index = hi) <= a.length) {
868	+	for (E e;; ++i) {
869	+	if (i < hi) {
870	+	if ((e = (E) a[i]) == null) // must be CME
871	+	break;
872	+	action.accept(e);
873	+	}
874	+	else if (q.modCount != mc)
875	+	break;
876	+	else
877	+	return;
878	+	}
879	+	}
880	+	}
881	+	throw new ConcurrentModificationException();
882	+	}
883	+
884	+	public boolean tryAdvance(Consumer<? super E> action) {
885	+	if (action == null)
886	+	throw new NullPointerException();
887	+	int hi = getFence(), lo = index;
888	+	if (lo >= 0 && lo < hi) {
889	+	index = lo + 1;
890	+	@SuppressWarnings("unchecked") E e = (E)pq.queue[lo];
891	+	if (e == null)
892	+	throw new ConcurrentModificationException();
893	+	action.accept(e);
894	+	if (pq.modCount != expectedModCount)
895	+	throw new ConcurrentModificationException();
896	+	return true;
897	+	}
898	+	return false;
899	+	}
900	+
901	+	public long estimateSize() {
902	+	return (long) (getFence() - index);
903	+	}
904	+
905	+	public int characteristics() {
906	+	return Spliterator.SIZED | Spliterator.SUBSIZED | Spliterator.NONNULL;
907	+	}
908	+	}
909		}

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