1 |
|
/* |
2 |
< |
* Copyright 2003-2006 Sun Microsystems, Inc. All Rights Reserved. |
2 |
> |
* Copyright (c) 2003, 2006, 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 |
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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
22 |
< |
* CA 95054 USA or visit www.sun.com if you need additional information or |
23 |
< |
* have any questions. |
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; |
56 |
|
* the priority queue in any particular order. If you need ordered |
57 |
|
* traversal, consider using {@code Arrays.sort(pq.toArray())}. |
58 |
|
* |
59 |
< |
* <p> <strong>Note that this implementation is not synchronized.</strong> |
59 |
> |
* <p><strong>Note that this implementation is not synchronized.</strong> |
60 |
|
* Multiple threads should not access a {@code PriorityQueue} |
61 |
|
* instance concurrently if any of the threads modifies the queue. |
62 |
|
* Instead, use the thread-safe {@link |
63 |
|
* java.util.concurrent.PriorityBlockingQueue} class. |
64 |
|
* |
65 |
|
* <p>Implementation note: this implementation provides |
66 |
< |
* O(log(n)) time for the enqueing and dequeing methods |
66 |
> |
* O(log(n)) time for the enqueuing and dequeuing methods |
67 |
|
* ({@code offer}, {@code poll}, {@code remove()} and {@code add}); |
68 |
|
* linear time for the {@code remove(Object)} and {@code contains(Object)} |
69 |
|
* methods; and constant time for the retrieval methods |
77 |
|
* @author Josh Bloch, Doug Lea |
78 |
|
* @param <E> the type of elements held in this collection |
79 |
|
*/ |
80 |
+ |
@SuppressWarnings("unchecked") |
81 |
|
public class PriorityQueue<E> extends AbstractQueue<E> |
82 |
|
implements java.io.Serializable { |
83 |
|
|
332 |
|
} |
333 |
|
|
334 |
|
public E peek() { |
335 |
< |
if (size == 0) |
335 |
< |
return null; |
336 |
< |
return (E) queue[0]; |
335 |
> |
return (size == 0) ? null : (E) queue[0]; |
336 |
|
} |
337 |
|
|
338 |
|
private int indexOf(Object o) { |
433 |
|
* The following code can be used to dump the queue into a newly |
434 |
|
* allocated array of <tt>String</tt>: |
435 |
|
* |
436 |
< |
* <pre> |
438 |
< |
* String[] y = x.toArray(new String[0]);</pre> |
436 |
> |
* <pre> {@code String[] y = x.toArray(new String[0]);}</pre> |
437 |
|
* |
438 |
|
* Note that <tt>toArray(new Object[0])</tt> is identical in function to |
439 |
|
* <tt>toArray()</tt>. |
590 |
|
* avoid missing traversing elements. |
591 |
|
*/ |
592 |
|
private E removeAt(int i) { |
593 |
< |
assert i >= 0 && i < size; |
593 |
> |
// assert i >= 0 && i < size; |
594 |
|
modCount++; |
595 |
|
int s = --size; |
596 |
|
if (s == i) // removed last element |
725 |
|
} |
726 |
|
|
727 |
|
/** |
728 |
< |
* Saves the state of the instance to a stream (that |
731 |
< |
* is, serializes it). |
728 |
> |
* Saves this queue to a stream (that is, serializes it). |
729 |
|
* |
730 |
|
* @serialData The length of the array backing the instance is |
731 |
|
* emitted (int), followed by all of its elements |
732 |
|
* (each an {@code Object}) in the proper order. |
736 |
– |
* @param s the stream |
733 |
|
*/ |
734 |
|
private void writeObject(java.io.ObjectOutputStream s) |
735 |
< |
throws java.io.IOException{ |
735 |
> |
throws java.io.IOException { |
736 |
|
// Write out element count, and any hidden stuff |
737 |
|
s.defaultWriteObject(); |
738 |
|
|
745 |
|
} |
746 |
|
|
747 |
|
/** |
748 |
< |
* Reconstitutes the {@code PriorityQueue} instance from a stream |
753 |
< |
* (that is, deserializes it). |
754 |
< |
* |
755 |
< |
* @param s the stream |
748 |
> |
* Reconstitutes this queue from a stream (that is, deserializes it). |
749 |
|
*/ |
750 |
|
private void readObject(java.io.ObjectInputStream s) |
751 |
|
throws java.io.IOException, ClassNotFoundException { |