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root/jsr166/jsr166/src/main/java/util/PriorityQueue.java

Comparing jsr166/src/main/java/util/PriorityQueue.java (file contents):
Revision 1.99 by jsr166, Fri Apr 11 21:15:44 2014 UTC vs.
Revision 1.117 by jsr166, Tue Dec 20 22:37:31 2016 UTC

#	Line 1 | Line 1
1		/*
2	<	* Copyright (c) 2003, 2012, 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
#	Line 24 | Line 24
24		*/
25
26		package java.util;
27	+
28		import java.util.function.Consumer;
28	–	import java.util.stream.Stream;
29
30		/**
31		* An unbounded priority {@linkplain Queue queue} based on a priority heap.
#	Line 54 | Line 54 | import java.util.stream.Stream;
54		* <p>This class and its iterator implement all of the
55		* <em>optional</em> methods of the {@link Collection} and {@link
56		* Iterator} interfaces.  The Iterator provided in method {@link
57	<	* #iterator()} is <em>not</em> guaranteed to traverse the elements of
57	>	* #iterator()} and the Spliterator provided in method {@link #spliterator()}
58	>	* are <em>not</em> guaranteed to traverse the elements of
59		* the priority queue in any particular order. If you need ordered
60		* traversal, consider using {@code Arrays.sort(pq.toArray())}.
61		*
#	Line 77 | Line 78 | import java.util.stream.Stream;
78		*
79		* @since 1.5
80		* @author Josh Bloch, Doug Lea
81	<	* @param <E> the type of elements held in this collection
81	>	* @param <E> the type of elements held in this queue
82		*/
83		public class PriorityQueue<E> extends AbstractQueue<E>
84		implements java.io.Serializable {
#	Line 99 | Line 100 | public class PriorityQueue<E> extends Ab
100		/**
101		* The number of elements in the priority queue.
102		*/
103	<	private int size;
103	>	int size;
104
105		/**
106		* The comparator, or null if priority queue uses elements'
#	Line 111 | Line 112 | public class PriorityQueue<E> extends Ab
112		* The number of times this priority queue has been
113		* <i>structurally modified</i>.  See AbstractList for gory details.
114		*/
115	<	transient int modCount = 0; // non-private to simplify nested class access
115	>	transient int modCount;     // non-private to simplify nested class access
116
117		/**
118		* Creates a {@code PriorityQueue} with the default initial
#	Line 136 | Line 137 | public class PriorityQueue<E> extends Ab
137		}
138
139		/**
140	+	* Creates a {@code PriorityQueue} with the default initial capacity and
141	+	* whose elements are ordered according to the specified comparator.
142	+	*
143	+	* @param  comparator the comparator that will be used to order this
144	+	*         priority queue.  If {@code null}, the {@linkplain Comparable
145	+	*         natural ordering} of the elements will be used.
146	+	* @since 1.8
147	+	*/
148	+	public PriorityQueue(Comparator<? super E> comparator) {
149	+	this(DEFAULT_INITIAL_CAPACITY, comparator);
150	+	}
151	+
152	+	/**
153		* Creates a {@code PriorityQueue} with the specified initial capacity
154		* that orders its elements according to the specified comparator.
155		*
#	Line 245 | Line 259 | public class PriorityQueue<E> extends Ab
259		a = Arrays.copyOf(a, a.length, Object[].class);
260		int len = a.length;
261		if (len == 1 || this.comparator != null)
262	<	for (int i = 0; i < len; i++)
263	<	if (a[i] == null)
262	>	for (Object e : a)
263	>	if (e == null)
264		throw new NullPointerException();
265		this.queue = a;
266		this.size = a.length;
#	Line 324 | Line 338 | public class PriorityQueue<E> extends Ab
338		int i = size;
339		if (i >= queue.length)
340		grow(i + 1);
341	+	siftUp(i, e);
342		size = i + 1;
328	–	if (i == 0)
329	–	queue[0] = e;
330	–	else
331	–	siftUp(i, e);
343		return true;
344		}
345
#	Line 393 | Line 404 | public class PriorityQueue<E> extends Ab
404		* @return {@code true} if this queue contains the specified element
405		*/
406		public boolean contains(Object o) {
407	<	return indexOf(o) != -1;
407	>	return indexOf(o) >= 0;
408		}
409
410		/**
#	Line 435 | Line 446 | public class PriorityQueue<E> extends Ab
446		* The following code can be used to dump the queue into a newly
447		* allocated array of {@code String}:
448		*
449	<	*  <pre> {@code String[] y = x.toArray(new String[0]);}</pre>
449	>	* <pre> {@code String[] y = x.toArray(new String[0]);}</pre>
450		*
451		* Note that {@code toArray(new Object[0])} is identical in function to
452		* {@code toArray()}.
#	Line 511 | Line 522 | public class PriorityQueue<E> extends Ab
522		*/
523		private int expectedModCount = modCount;
524
525	+	Itr() {}                        // prevent access constructor creation
526	+
527		public boolean hasNext() {
528		return cursor < size ||
529		(forgetMeNot != null && !forgetMeNot.isEmpty());
#	Line 596 | Line 609 | public class PriorityQueue<E> extends Ab
609		* avoid missing traversing elements.
610		*/
611		@SuppressWarnings("unchecked")
612	<	private E removeAt(int i) {
612	>	E removeAt(int i) {
613		// assert i >= 0 && i < size;
614		modCount++;
615		int s = --size;
#	Line 620 | Line 633 | public class PriorityQueue<E> extends Ab
633		* promoting x up the tree until it is greater than or equal to
634		* its parent, or is the root.
635		*
636	<	* To simplify and speed up coercions and comparisons. the
636	>	* To simplify and speed up coercions and comparisons, the
637		* Comparable and Comparator versions are separated into different
638		* methods that are otherwise identical. (Similarly for siftDown.)
639		*
#	Line 716 | Line 729 | public class PriorityQueue<E> extends Ab
729		/**
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	+	* This classic algorithm due to Floyd (1964) is known to be O(size).
733		*/
734		@SuppressWarnings("unchecked")
735		private void heapify() {
736	<	for (int i = (size >>> 1) - 1; i >= 0; i--)
737	<	siftDown(i, (E) queue[i]);
736	>	final Object[] es = queue;
737	>	final int half = (size >>> 1) - 1;
738	>	if (comparator == null)
739	>	for (int i = half; i >= 0; i--)
740	>	siftDownComparable(i, (E) es[i]);
741	>	else
742	>	for (int i = half; i >= 0; i--)
743	>	siftDownUsingComparator(i, (E) es[i]);
744		}
745
746		/**
#	Line 739 | Line 759 | public class PriorityQueue<E> extends Ab
759		/**
760		* Saves this queue to a stream (that is, serializes it).
761		*
762	+	* @param s the stream
763	+	* @throws java.io.IOException if an I/O error occurs
764		* @serialData The length of the array backing the instance is
765		*             emitted (int), followed by all of its elements
766		*             (each an {@code Object}) in the proper order.
745	–	* @param s the stream
746	–	* @throws java.io.IOException if an I/O error occurs
767		*/
768		private void writeObject(java.io.ObjectOutputStream s)
769		throws java.io.IOException {
#	Line 786 | Line 806 | public class PriorityQueue<E> extends Ab
806		heapify();
807		}
808
789	–	public Spliterator<E> spliterator() {
790	–	return new PriorityQueueSpliterator<E>(this, 0, -1, 0);
791	–	}
792	–
809		/**
810	<	* This is very similar to ArrayList Spliterator, except for extra
811	<	* null checks.
810	>	* Creates a <em><a href="Spliterator.html#binding">late-binding</a></em>
811	>	* and <em>fail-fast</em> {@link Spliterator} over the elements in this
812	>	* queue. The spliterator does not traverse elements in any particular order
813	>	* (the {@link Spliterator#ORDERED ORDERED} characteristic is not reported).
814	>	*
815	>	* <p>The {@code Spliterator} reports {@link Spliterator#SIZED},
816	>	* {@link Spliterator#SUBSIZED}, and {@link Spliterator#NONNULL}.
817	>	* Overriding implementations should document the reporting of additional
818	>	* characteristic values.
819	>	*
820	>	* @return a {@code Spliterator} over the elements in this queue
821	>	* @since 1.8
822		*/
823	<	static final class PriorityQueueSpliterator<E> implements Spliterator<E> {
824	<	private final PriorityQueue<E> pq;
823	>	public final Spliterator<E> spliterator() {
824	>	return new PriorityQueueSpliterator(0, -1, 0);
825	>	}
826	>
827	>	final class PriorityQueueSpliterator implements Spliterator<E> {
828		private int index;            // current index, modified on advance/split
829		private int fence;            // -1 until first use
830		private int expectedModCount; // initialized when fence set
831
832	<	/** Creates new spliterator covering the given range */
833	<	PriorityQueueSpliterator(PriorityQueue<E> pq, int origin, int fence,
805	<	int expectedModCount) {
806	<	this.pq = pq;
832	>	/** Creates new spliterator covering the given range. */
833	>	PriorityQueueSpliterator(int origin, int fence, int expectedModCount) {
834		this.index = origin;
835		this.fence = fence;
836		this.expectedModCount = expectedModCount;
#	Line 812 | Line 839 | public class PriorityQueue<E> extends Ab
839		private int getFence() { // initialize fence to size on first use
840		int hi;
841		if ((hi = fence) < 0) {
842	<	expectedModCount = pq.modCount;
843	<	hi = fence = pq.size;
842	>	expectedModCount = modCount;
843	>	hi = fence = size;
844		}
845		return hi;
846		}
847
848	<	public Spliterator<E> trySplit() {
848	>	public PriorityQueueSpliterator trySplit() {
849		int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
850		return (lo >= mid) ? null :
851	<	new PriorityQueueSpliterator<E>(pq, lo, index = mid,
825	<	expectedModCount);
851	>	new PriorityQueueSpliterator(lo, index = mid, expectedModCount);
852		}
853
854		@SuppressWarnings("unchecked")
855		public void forEachRemaining(Consumer<? super E> action) {
830	–	int i, hi, mc; // hoist accesses and checks from loop
831	–	PriorityQueue<E> q; Object[] a;
856		if (action == null)
857		throw new NullPointerException();
858	<	if ((q = pq) != null && (a = q.queue) != null) {
859	<	if ((hi = fence) < 0) {
860	<	mc = q.modCount;
861	<	hi = q.size;
862	<	}
863	<	else
864	<	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	<	}
858	>	if (fence < 0) { fence = size; expectedModCount = modCount; }
859	>	final Object[] a = queue;
860	>	int i, hi; E e;
861	>	for (i = index, index = hi = fence; i < hi; i++) {
862	>	if ((e = (E) a[i]) == null)
863	>	break;      // must be CME
864	>	action.accept(e);
865		}
866	<	throw new ConcurrentModificationException();
866	>	if (modCount != expectedModCount)
867	>	throw new ConcurrentModificationException();
868		}
869
870	+	@SuppressWarnings("unchecked")
871		public boolean tryAdvance(Consumer<? super E> action) {
872	<	int hi = getFence(), lo = index;
873	<	if (lo >= 0 && lo < hi) {
874	<	index = lo + 1;
875	<	@SuppressWarnings("unchecked") E e = (E)pq.queue[lo];
876	<	if (e == null)
872	>	if (action == null)
873	>	throw new NullPointerException();
874	>	if (fence < 0) { fence = size; expectedModCount = modCount; }
875	>	int i;
876	>	if ((i = index) < fence) {
877	>	index = i + 1;
878	>	E e;
879	>	if ((e = (E) queue[i]) == null
880	>	|| modCount != expectedModCount)
881		throw new ConcurrentModificationException();
882		action.accept(e);
866	–	if (pq.modCount != expectedModCount)
867	–	throw new ConcurrentModificationException();
883		return true;
884		}
885		return false;
886		}
887
888		public long estimateSize() {
889	<	return (long) (getFence() - index);
889	>	return getFence() - index;
890		}
891
892		public int characteristics() {

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