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

Comparing jsr166/src/main/java/util/PriorityQueue.java (file contents):
Revision 1.88 by dl, Fri Feb 1 16:23:04 2013 UTC vs.
Revision 1.107 by jsr166, Sun Sep 20 16:20:21 2015 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	<	import java.util.stream.Stream;
28	<	import java.util.Spliterator;
29	<	import java.util.stream.Streams;
27	>
28		import java.util.function.Consumer;
29
30		/**
#	Line 67 | Line 65 | import java.util.function.Consumer;
65		* java.util.concurrent.PriorityBlockingQueue} class.
66		*
67		* <p>Implementation note: this implementation provides
68	<	* O(log(n)) time for the enqueing and dequeing methods
68	>	* O(log(n)) time for the enqueuing and dequeuing methods
69		* ({@code offer}, {@code poll}, {@code remove()} and {@code add});
70		* linear time for the {@code remove(Object)} and {@code contains(Object)}
71		* methods; and constant time for the retrieval methods
#	Line 79 | Line 77 | import java.util.function.Consumer;
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		*/
82		public class PriorityQueue<E> extends AbstractQueue<E>
83		implements java.io.Serializable {
#	Line 101 | Line 99 | public class PriorityQueue<E> extends Ab
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 113 | 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	<	transient int modCount = 0; // non-private to simplify nested class access
114	>	transient int modCount;     // non-private to simplify nested class access
115
116		/**
117		* Creates a {@code PriorityQueue} with the default initial
#	Line 138 | 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 247 | 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 395 | 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 437 | 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 478 | 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 498 | 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 543 | 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 598 | 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 745 | Line 756 | public class PriorityQueue<E> extends Ab
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 764 | Line 776 | public class PriorityQueue<E> extends Ab
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 784 | Line 799 | public class PriorityQueue<E> extends Ab
799		heapify();
800		}
801
802	<	// wrapping constructor in method avoids transient javac problems
803	<	final PriorityQueueSpliterator<E> spliterator(int origin, int fence,
804	<	int expectedModCount) {
805	<	return new PriorityQueueSpliterator<E>(this, origin, fence,
806	<	expectedModCount);
807	<	}
808	<
809	<	public Stream<E> stream() {
810	<	int flags = Streams.STREAM_IS_SIZED;
811	<	return Streams.stream
812	<	(() -> spliterator(0, size, modCount), flags);
813	<	}
814	<	public Stream<E> parallelStream() {
815	<	int flags = Streams.STREAM_IS_SIZED;
816	<	return Streams.parallelStream
802	<	(() -> spliterator(0, size, modCount), flags);
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
805	–	/** Index-based split-by-two Spliterator */
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 final int fence;     // one past last index
827	<	private final int expectedModCount; // for comodification checks
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	<	/** Create new spliterator covering the given  range */
829	>	/** Creates new spliterator covering the given range */
830		PriorityQueueSpliterator(PriorityQueue<E> pq, int origin, int fence,
831	<	int expectedModCount) {
832	<	this.pq = pq; this.index = origin; this.fence = 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 lo = index, mid = (lo + fence) >>> 1;
848	>	int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
849		return (lo >= mid) ? null :
850	<	new PriorityQueueSpliterator<E>(pq, lo, index = mid,
851	<	expectedModCount);
850	>	new PriorityQueueSpliterator<>(pq, lo, index = mid,
851	>	expectedModCount);
852		}
853
854	<	public void forEach(Consumer<? super E> block) {
855	<	Object[] a; int i, hi; // hoist accesses and checks from loop
856	<	if (block == null)
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 ((a = pq.queue).length >= (hi = fence) &&
861	<	(i = index) >= 0 && i < hi) {
862	<	index = hi;
863	<	do {
864	<	@SuppressWarnings("unchecked") E e = (E) a[i];
865	<	block.accept(e);
866	<	} while (++i < hi);
867	<	if (pq.modCount != expectedModCount)
868	<	throw new ConcurrentModificationException();
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> block) {
885	<	if (index >= 0 && index < fence) {
886	<	@SuppressWarnings("unchecked") E e =
887	<	(E)pq.queue[index++];
888	<	block.accept(e);
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;
#	Line 851 | Line 898 | public class PriorityQueue<E> extends Ab
898		return false;
899		}
900
901	<	public long estimateSize() { return (long)(fence - index); }
902	<	public boolean hasExactSize() { return true; }
903	<	public boolean hasExactSplits() { return true; }
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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