1 |
|
/* |
2 |
< |
* %W% %E% |
2 |
> |
* Copyright (c) 2003, 2012, 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 |
+ |
|
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 |
58 |
|
* the priority queue in any particular order. If you need ordered |
59 |
|
* traversal, consider using {@code Arrays.sort(pq.toArray())}. |
60 |
|
* |
61 |
< |
* <p> <strong>Note that this implementation is not synchronized.</strong> |
61 |
> |
* <p><strong>Note that this implementation is not synchronized.</strong> |
62 |
|
* Multiple threads should not access a {@code PriorityQueue} |
63 |
|
* instance concurrently if any of the threads modifies the queue. |
64 |
|
* Instead, use the thread-safe {@link |
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 |
72 |
|
* ({@code peek}, {@code element}, and {@code size}). |
73 |
|
* |
74 |
|
* <p>This class is a member of the |
75 |
< |
* <a href="{@docRoot}/../guide/collections/index.html"> |
75 |
> |
* <a href="{@docRoot}/../technotes/guides/collections/index.html"> |
76 |
|
* Java Collections Framework</a>. |
77 |
|
* |
78 |
|
* @since 1.5 |
59 |
– |
* @version %I%, %G% |
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 { |
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 |
> |
private int size; |
103 |
|
|
104 |
|
/** |
105 |
|
* The comparator, or null if priority queue uses elements' |
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 for nested class access |
115 |
|
|
116 |
|
/** |
117 |
|
* Creates a {@code PriorityQueue} with the default initial |
172 |
|
* @throws NullPointerException if the specified collection or any |
173 |
|
* of its elements are null |
174 |
|
*/ |
175 |
+ |
@SuppressWarnings("unchecked") |
176 |
|
public PriorityQueue(Collection<? extends E> c) { |
177 |
< |
initFromCollection(c); |
178 |
< |
if (c instanceof SortedSet) |
179 |
< |
comparator = (Comparator<? super E>) |
180 |
< |
((SortedSet<? extends E>)c).comparator(); |
181 |
< |
else if (c instanceof PriorityQueue) |
182 |
< |
comparator = (Comparator<? super E>) |
183 |
< |
((PriorityQueue<? extends E>)c).comparator(); |
177 |
> |
if (c instanceof SortedSet<?>) { |
178 |
> |
SortedSet<? extends E> ss = (SortedSet<? extends E>) c; |
179 |
> |
this.comparator = (Comparator<? super E>) ss.comparator(); |
180 |
> |
initElementsFromCollection(ss); |
181 |
> |
} |
182 |
> |
else if (c instanceof PriorityQueue<?>) { |
183 |
> |
PriorityQueue<? extends E> pq = (PriorityQueue<? extends E>) c; |
184 |
> |
this.comparator = (Comparator<? super E>) pq.comparator(); |
185 |
> |
initFromPriorityQueue(pq); |
186 |
> |
} |
187 |
|
else { |
188 |
< |
comparator = null; |
189 |
< |
heapify(); |
188 |
> |
this.comparator = null; |
189 |
> |
initFromCollection(c); |
190 |
|
} |
191 |
|
} |
192 |
|
|
204 |
|
* @throws NullPointerException if the specified priority queue or any |
205 |
|
* of its elements are null |
206 |
|
*/ |
207 |
+ |
@SuppressWarnings("unchecked") |
208 |
|
public PriorityQueue(PriorityQueue<? extends E> c) { |
209 |
< |
comparator = (Comparator<? super E>)c.comparator(); |
210 |
< |
initFromCollection(c); |
209 |
> |
this.comparator = (Comparator<? super E>) c.comparator(); |
210 |
> |
initFromPriorityQueue(c); |
211 |
|
} |
212 |
|
|
213 |
|
/** |
223 |
|
* @throws NullPointerException if the specified sorted set or any |
224 |
|
* of its elements are null |
225 |
|
*/ |
226 |
+ |
@SuppressWarnings("unchecked") |
227 |
|
public PriorityQueue(SortedSet<? extends E> c) { |
228 |
< |
comparator = (Comparator<? super E>)c.comparator(); |
229 |
< |
initFromCollection(c); |
228 |
> |
this.comparator = (Comparator<? super E>) c.comparator(); |
229 |
> |
initElementsFromCollection(c); |
230 |
> |
} |
231 |
> |
|
232 |
> |
private void initFromPriorityQueue(PriorityQueue<? extends E> c) { |
233 |
> |
if (c.getClass() == PriorityQueue.class) { |
234 |
> |
this.queue = c.toArray(); |
235 |
> |
this.size = c.size(); |
236 |
> |
} else { |
237 |
> |
initFromCollection(c); |
238 |
> |
} |
239 |
> |
} |
240 |
> |
|
241 |
> |
private void initElementsFromCollection(Collection<? extends E> c) { |
242 |
> |
Object[] a = c.toArray(); |
243 |
> |
// If c.toArray incorrectly doesn't return Object[], copy it. |
244 |
> |
if (a.getClass() != Object[].class) |
245 |
> |
a = Arrays.copyOf(a, a.length, Object[].class); |
246 |
> |
int len = a.length; |
247 |
> |
if (len == 1 || this.comparator != null) |
248 |
> |
for (int i = 0; i < len; i++) |
249 |
> |
if (a[i] == null) |
250 |
> |
throw new NullPointerException(); |
251 |
> |
this.queue = a; |
252 |
> |
this.size = a.length; |
253 |
|
} |
254 |
|
|
255 |
|
/** |
258 |
|
* @param c the collection |
259 |
|
*/ |
260 |
|
private void initFromCollection(Collection<? extends E> c) { |
261 |
< |
Object[] a = c.toArray(); |
262 |
< |
// 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; |
261 |
> |
initElementsFromCollection(c); |
262 |
> |
heapify(); |
263 |
|
} |
264 |
|
|
265 |
|
/** |
266 |
+ |
* The maximum size of array to allocate. |
267 |
+ |
* Some VMs reserve some header words in an array. |
268 |
+ |
* Attempts to allocate larger arrays may result in |
269 |
+ |
* OutOfMemoryError: Requested array size exceeds VM limit |
270 |
+ |
*/ |
271 |
+ |
private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8; |
272 |
+ |
|
273 |
+ |
/** |
274 |
|
* Increases the capacity of the array. |
275 |
|
* |
276 |
|
* @param minCapacity the desired minimum capacity |
277 |
|
*/ |
278 |
|
private void grow(int minCapacity) { |
279 |
< |
if (minCapacity < 0) // overflow |
228 |
< |
throw new OutOfMemoryError(); |
229 |
< |
int oldCapacity = queue.length; |
279 |
> |
int oldCapacity = queue.length; |
280 |
|
// Double size if small; else grow by 50% |
281 |
< |
int newCapacity = ((oldCapacity < 64)? |
282 |
< |
((oldCapacity + 1) * 2): |
283 |
< |
((oldCapacity / 2) * 3)); |
284 |
< |
if (newCapacity < 0) // overflow |
285 |
< |
newCapacity = Integer.MAX_VALUE; |
286 |
< |
if (newCapacity < minCapacity) |
237 |
< |
newCapacity = minCapacity; |
281 |
> |
int newCapacity = oldCapacity + ((oldCapacity < 64) ? |
282 |
> |
(oldCapacity + 2) : |
283 |
> |
(oldCapacity >> 1)); |
284 |
> |
// overflow-conscious code |
285 |
> |
if (newCapacity - MAX_ARRAY_SIZE > 0) |
286 |
> |
newCapacity = hugeCapacity(minCapacity); |
287 |
|
queue = Arrays.copyOf(queue, newCapacity); |
288 |
|
} |
289 |
|
|
290 |
+ |
private static int hugeCapacity(int minCapacity) { |
291 |
+ |
if (minCapacity < 0) // overflow |
292 |
+ |
throw new OutOfMemoryError(); |
293 |
+ |
return (minCapacity > MAX_ARRAY_SIZE) ? |
294 |
+ |
Integer.MAX_VALUE : |
295 |
+ |
MAX_ARRAY_SIZE; |
296 |
+ |
} |
297 |
+ |
|
298 |
|
/** |
299 |
|
* Inserts the specified element into this priority queue. |
300 |
|
* |
332 |
|
return true; |
333 |
|
} |
334 |
|
|
335 |
+ |
@SuppressWarnings("unchecked") |
336 |
|
public E peek() { |
337 |
< |
if (size == 0) |
280 |
< |
return null; |
281 |
< |
return (E) queue[0]; |
337 |
> |
return (size == 0) ? null : (E) queue[0]; |
338 |
|
} |
339 |
|
|
340 |
|
private int indexOf(Object o) { |
341 |
< |
if (o != null) { |
341 |
> |
if (o != null) { |
342 |
|
for (int i = 0; i < size; i++) |
343 |
|
if (o.equals(queue[i])) |
344 |
|
return i; |
358 |
|
* @return {@code true} if this queue changed as a result of the call |
359 |
|
*/ |
360 |
|
public boolean remove(Object o) { |
361 |
< |
int i = indexOf(o); |
362 |
< |
if (i == -1) |
363 |
< |
return false; |
364 |
< |
else { |
365 |
< |
removeAt(i); |
366 |
< |
return true; |
367 |
< |
} |
361 |
> |
int i = indexOf(o); |
362 |
> |
if (i == -1) |
363 |
> |
return false; |
364 |
> |
else { |
365 |
> |
removeAt(i); |
366 |
> |
return true; |
367 |
> |
} |
368 |
|
} |
369 |
|
|
370 |
|
/** |
375 |
|
* @return {@code true} if removed |
376 |
|
*/ |
377 |
|
boolean removeEq(Object o) { |
378 |
< |
for (int i = 0; i < size; i++) { |
379 |
< |
if (o == queue[i]) { |
378 |
> |
for (int i = 0; i < size; i++) { |
379 |
> |
if (o == queue[i]) { |
380 |
|
removeAt(i); |
381 |
|
return true; |
382 |
|
} |
393 |
|
* @return {@code true} if this queue contains the specified element |
394 |
|
*/ |
395 |
|
public boolean contains(Object o) { |
396 |
< |
return indexOf(o) != -1; |
396 |
> |
return indexOf(o) >= 0; |
397 |
|
} |
398 |
|
|
399 |
|
/** |
431 |
|
* precise control over the runtime type of the output array, and may, |
432 |
|
* under certain circumstances, be used to save allocation costs. |
433 |
|
* |
434 |
< |
* <p>Suppose <tt>x</tt> is a queue known to contain only strings. |
434 |
> |
* <p>Suppose {@code x} is a queue known to contain only strings. |
435 |
|
* The following code can be used to dump the queue into a newly |
436 |
< |
* allocated array of <tt>String</tt>: |
436 |
> |
* allocated array of {@code String}: |
437 |
|
* |
438 |
< |
* <pre> |
383 |
< |
* String[] y = x.toArray(new String[0]);</pre> |
438 |
> |
* <pre> {@code String[] y = x.toArray(new String[0]);}</pre> |
439 |
|
* |
440 |
< |
* Note that <tt>toArray(new Object[0])</tt> is identical in function to |
441 |
< |
* <tt>toArray()</tt>. |
440 |
> |
* Note that {@code toArray(new Object[0])} is identical in function to |
441 |
> |
* {@code toArray()}. |
442 |
|
* |
443 |
|
* @param a the array into which the elements of the queue are to |
444 |
|
* be stored, if it is big enough; otherwise, a new array of the |
449 |
|
* this queue |
450 |
|
* @throws NullPointerException if the specified array is null |
451 |
|
*/ |
452 |
+ |
@SuppressWarnings("unchecked") |
453 |
|
public <T> T[] toArray(T[] a) { |
454 |
+ |
final int size = this.size; |
455 |
|
if (a.length < size) |
456 |
|
// Make a new array of a's runtime type, but my contents: |
457 |
|
return (T[]) Arrays.copyOf(queue, size, a.getClass()); |
458 |
< |
System.arraycopy(queue, 0, a, 0, size); |
458 |
> |
System.arraycopy(queue, 0, a, 0, size); |
459 |
|
if (a.length > size) |
460 |
|
a[size] = null; |
461 |
|
return a; |
476 |
|
* Index (into queue array) of element to be returned by |
477 |
|
* subsequent call to next. |
478 |
|
*/ |
479 |
< |
private int cursor = 0; |
479 |
> |
private int cursor; |
480 |
|
|
481 |
|
/** |
482 |
|
* Index of element returned by most recent call to next, |
496 |
|
* We expect that most iterations, even those involving removals, |
497 |
|
* will not need to store elements in this field. |
498 |
|
*/ |
499 |
< |
private ArrayDeque<E> forgetMeNot = null; |
499 |
> |
private ArrayDeque<E> forgetMeNot; |
500 |
|
|
501 |
|
/** |
502 |
|
* Element returned by the most recent call to next iff that |
503 |
|
* element was drawn from the forgetMeNot list. |
504 |
|
*/ |
505 |
< |
private E lastRetElt = null; |
505 |
> |
private E lastRetElt; |
506 |
|
|
507 |
|
/** |
508 |
|
* The modCount value that the iterator believes that the backing |
516 |
|
(forgetMeNot != null && !forgetMeNot.isEmpty()); |
517 |
|
} |
518 |
|
|
519 |
+ |
@SuppressWarnings("unchecked") |
520 |
|
public E next() { |
521 |
|
if (expectedModCount != modCount) |
522 |
|
throw new ConcurrentModificationException(); |
541 |
|
cursor--; |
542 |
|
else { |
543 |
|
if (forgetMeNot == null) |
544 |
< |
forgetMeNot = new ArrayDeque<E>(); |
544 |
> |
forgetMeNot = new ArrayDeque<>(); |
545 |
|
forgetMeNot.add(moved); |
546 |
|
} |
547 |
|
} else if (lastRetElt != null) { |
549 |
|
lastRetElt = null; |
550 |
|
} else { |
551 |
|
throw new IllegalStateException(); |
552 |
< |
} |
552 |
> |
} |
553 |
|
expectedModCount = modCount; |
554 |
|
} |
555 |
|
} |
569 |
|
size = 0; |
570 |
|
} |
571 |
|
|
572 |
+ |
@SuppressWarnings("unchecked") |
573 |
|
public E poll() { |
574 |
|
if (size == 0) |
575 |
|
return null; |
595 |
|
* position before i. This fact is used by iterator.remove so as to |
596 |
|
* avoid missing traversing elements. |
597 |
|
*/ |
598 |
+ |
@SuppressWarnings("unchecked") |
599 |
|
private E removeAt(int i) { |
600 |
< |
assert i >= 0 && i < size; |
600 |
> |
// assert i >= 0 && i < size; |
601 |
|
modCount++; |
602 |
|
int s = --size; |
603 |
|
if (s == i) // removed last element |
634 |
|
siftUpComparable(k, x); |
635 |
|
} |
636 |
|
|
637 |
+ |
@SuppressWarnings("unchecked") |
638 |
|
private void siftUpComparable(int k, E x) { |
639 |
|
Comparable<? super E> key = (Comparable<? super E>) x; |
640 |
|
while (k > 0) { |
648 |
|
queue[k] = key; |
649 |
|
} |
650 |
|
|
651 |
+ |
@SuppressWarnings("unchecked") |
652 |
|
private void siftUpUsingComparator(int k, E x) { |
653 |
|
while (k > 0) { |
654 |
|
int parent = (k - 1) >>> 1; |
676 |
|
siftDownComparable(k, x); |
677 |
|
} |
678 |
|
|
679 |
+ |
@SuppressWarnings("unchecked") |
680 |
|
private void siftDownComparable(int k, E x) { |
681 |
|
Comparable<? super E> key = (Comparable<? super E>)x; |
682 |
|
int half = size >>> 1; // loop while a non-leaf |
695 |
|
queue[k] = key; |
696 |
|
} |
697 |
|
|
698 |
+ |
@SuppressWarnings("unchecked") |
699 |
|
private void siftDownUsingComparator(int k, E x) { |
700 |
|
int half = size >>> 1; |
701 |
|
while (k < half) { |
717 |
|
* Establishes the heap invariant (described above) in the entire tree, |
718 |
|
* assuming nothing about the order of the elements prior to the call. |
719 |
|
*/ |
720 |
+ |
@SuppressWarnings("unchecked") |
721 |
|
private void heapify() { |
722 |
|
for (int i = (size >>> 1) - 1; i >= 0; i--) |
723 |
|
siftDown(i, (E) queue[i]); |
737 |
|
} |
738 |
|
|
739 |
|
/** |
740 |
< |
* Saves the state of the instance to a stream (that |
676 |
< |
* is, serializes it). |
740 |
> |
* Saves this queue to a stream (that is, serializes it). |
741 |
|
* |
742 |
|
* @serialData The length of the array backing the instance is |
743 |
|
* emitted (int), followed by all of its elements |
744 |
|
* (each an {@code Object}) in the proper order. |
745 |
|
* @param s the stream |
746 |
+ |
* @throws java.io.IOException if an I/O error occurs |
747 |
|
*/ |
748 |
|
private void writeObject(java.io.ObjectOutputStream s) |
749 |
< |
throws java.io.IOException{ |
749 |
> |
throws java.io.IOException { |
750 |
|
// Write out element count, and any hidden stuff |
751 |
|
s.defaultWriteObject(); |
752 |
|
|
753 |
|
// Write out array length, for compatibility with 1.5 version |
754 |
|
s.writeInt(Math.max(2, size + 1)); |
755 |
|
|
756 |
< |
// Write out all elements in the proper order. |
756 |
> |
// Write out all elements in the "proper order". |
757 |
|
for (int i = 0; i < size; i++) |
758 |
|
s.writeObject(queue[i]); |
759 |
|
} |
763 |
|
* (that is, deserializes it). |
764 |
|
* |
765 |
|
* @param s the stream |
766 |
+ |
* @throws ClassNotFoundException if the class of a serialized object |
767 |
+ |
* could not be found |
768 |
+ |
* @throws java.io.IOException if an I/O error occurs |
769 |
|
*/ |
770 |
|
private void readObject(java.io.ObjectInputStream s) |
771 |
|
throws java.io.IOException, ClassNotFoundException { |
775 |
|
// Read in (and discard) array length |
776 |
|
s.readInt(); |
777 |
|
|
778 |
< |
queue = new Object[size]; |
778 |
> |
queue = new Object[size]; |
779 |
|
|
780 |
< |
// Read in all elements in the proper order. |
780 |
> |
// Read in all elements. |
781 |
|
for (int i = 0; i < size; i++) |
782 |
|
queue[i] = s.readObject(); |
783 |
+ |
|
784 |
+ |
// Elements are guaranteed to be in "proper order", but the |
785 |
+ |
// spec has never explained what that might be. |
786 |
+ |
heapify(); |
787 |
+ |
} |
788 |
+ |
|
789 |
+ |
public Spliterator<E> spliterator() { |
790 |
+ |
return new PriorityQueueSpliterator<E>(this, 0, -1, 0); |
791 |
+ |
} |
792 |
+ |
|
793 |
+ |
/** |
794 |
+ |
* This is very similar to ArrayList Spliterator, except for extra |
795 |
+ |
* null checks. |
796 |
+ |
*/ |
797 |
+ |
static final class PriorityQueueSpliterator<E> implements Spliterator<E> { |
798 |
+ |
private final PriorityQueue<E> pq; |
799 |
+ |
private int index; // current index, modified on advance/split |
800 |
+ |
private int fence; // -1 until first use |
801 |
+ |
private int expectedModCount; // initialized when fence set |
802 |
+ |
|
803 |
+ |
/** Creates new spliterator covering the given range */ |
804 |
+ |
PriorityQueueSpliterator(PriorityQueue<E> pq, int origin, int fence, |
805 |
+ |
int expectedModCount) { |
806 |
+ |
this.pq = pq; |
807 |
+ |
this.index = origin; |
808 |
+ |
this.fence = fence; |
809 |
+ |
this.expectedModCount = expectedModCount; |
810 |
+ |
} |
811 |
+ |
|
812 |
+ |
private int getFence() { // initialize fence to size on first use |
813 |
+ |
int hi; |
814 |
+ |
if ((hi = fence) < 0) { |
815 |
+ |
expectedModCount = pq.modCount; |
816 |
+ |
hi = fence = pq.size; |
817 |
+ |
} |
818 |
+ |
return hi; |
819 |
+ |
} |
820 |
+ |
|
821 |
+ |
public Spliterator<E> trySplit() { |
822 |
+ |
int hi = getFence(), lo = index, mid = (lo + hi) >>> 1; |
823 |
+ |
return (lo >= mid) ? null : |
824 |
+ |
new PriorityQueueSpliterator<E>(pq, lo, index = mid, |
825 |
+ |
expectedModCount); |
826 |
+ |
} |
827 |
+ |
|
828 |
+ |
@SuppressWarnings("unchecked") |
829 |
+ |
public void forEachRemaining(Consumer<? super E> action) { |
830 |
+ |
int i, hi, mc; // hoist accesses and checks from loop |
831 |
+ |
PriorityQueue<E> q; Object[] a; |
832 |
+ |
if (action == null) |
833 |
+ |
throw new NullPointerException(); |
834 |
+ |
if ((q = pq) != null && (a = q.queue) != null) { |
835 |
+ |
if ((hi = fence) < 0) { |
836 |
+ |
mc = q.modCount; |
837 |
+ |
hi = q.size; |
838 |
+ |
} |
839 |
+ |
else |
840 |
+ |
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 |
+ |
} |
854 |
+ |
} |
855 |
+ |
throw new ConcurrentModificationException(); |
856 |
+ |
} |
857 |
+ |
|
858 |
+ |
public boolean tryAdvance(Consumer<? super E> action) { |
859 |
+ |
int hi = getFence(), lo = index; |
860 |
+ |
if (lo >= 0 && lo < hi) { |
861 |
+ |
index = lo + 1; |
862 |
+ |
@SuppressWarnings("unchecked") E e = (E)pq.queue[lo]; |
863 |
+ |
if (e == null) |
864 |
+ |
throw new ConcurrentModificationException(); |
865 |
+ |
action.accept(e); |
866 |
+ |
if (pq.modCount != expectedModCount) |
867 |
+ |
throw new ConcurrentModificationException(); |
868 |
+ |
return true; |
869 |
+ |
} |
870 |
+ |
return false; |
871 |
+ |
} |
872 |
+ |
|
873 |
+ |
public long estimateSize() { |
874 |
+ |
return (long) (getFence() - index); |
875 |
+ |
} |
876 |
+ |
|
877 |
+ |
public int characteristics() { |
878 |
+ |
return Spliterator.SIZED | Spliterator.SUBSIZED | Spliterator.NONNULL; |
879 |
+ |
} |
880 |
|
} |
881 |
|
} |