10 |
|
import java.util.concurrent.*; |
11 |
|
|
12 |
|
/** |
13 |
< |
* A scalable concurrent {@link SortedSet} and (priority) {@link |
14 |
< |
* Queue} implementation based on a {@link ConcurrentSkipListMap}. |
15 |
< |
* This class maintains a set in ascending order, sorted according to |
16 |
< |
* the <i>natural order</i> for the element's class (see {@link |
17 |
< |
* Comparable}), or by the comparator provided at creation time, |
18 |
< |
* depending on which constructor is used.<p> |
13 |
> |
* A scalable concurrent {@link NavigableSet} implementation based on |
14 |
> |
* a {@link ConcurrentSkipListMap}. This class maintains a set in |
15 |
> |
* ascending order, sorted according to the <i>natural order</i> for |
16 |
> |
* the element's class (see {@link Comparable}), or by the comparator |
17 |
> |
* provided at creation time, depending on which constructor is |
18 |
> |
* used.<p> |
19 |
|
* |
20 |
|
* This implementation provides expected average <i>log(n)</i> time |
21 |
|
* cost for the <tt>contains</tt>, <tt>add</tt>, and <tt>remove</tt> |
27 |
|
* ConcurrentModificationException}, and may procede concurrently with |
28 |
|
* other operations. |
29 |
|
* |
30 |
– |
* <p>This class provides extended <tt>SortedSet</tt> methods |
31 |
– |
* searching for closest matches. Methods <tt>lower</tt>, |
32 |
– |
* <tt>floor</tt>, <tt>ceiling</tt>, and <tt>higher</tt> return |
33 |
– |
* elements respectively less, less than or equal, greater than or |
34 |
– |
* equal, and greater than a given value, returning null if there is |
35 |
– |
* no such element. These methods are designed for locating, not |
36 |
– |
* traversing entries. To traverse, use iterators and/or |
37 |
– |
* <tt>subset</tt>. |
38 |
– |
* |
39 |
– |
* <p>The class additionally supports {@link Queue} methods such as |
40 |
– |
* <tt>poll</tt> that atomically returns and removes the first |
41 |
– |
* element, if one exists. Thus, this class can serve as a priority |
42 |
– |
* queue in which there are no duplicate elements. |
43 |
– |
* |
44 |
– |
* <p>The {@link ConcurrentSkipListSubSet} objects returned by methods |
45 |
– |
* <tt>subset</tt>, <tt>headSet</tt>, and <tt>tailSet</tt> support the |
46 |
– |
* same extended set of operations as this class, but operate on their |
47 |
– |
* designated subrange of elements. |
48 |
– |
* |
30 |
|
* <p>Beware that, unlike in most collections, the <tt>size</tt> |
31 |
|
* method is <em>NOT</em> a constant-time operation. Because of the |
32 |
|
* asynchronous nature of these sets, determining the current number |
44 |
|
*/ |
45 |
|
public class ConcurrentSkipListSet<E> |
46 |
|
extends AbstractSet<E> |
47 |
< |
implements SortedSet<E>, Queue<E>, Cloneable, java.io.Serializable { |
47 |
> |
implements NavigableSet<E>, Cloneable, java.io.Serializable { |
48 |
|
|
49 |
|
private static final long serialVersionUID = -2479143111061671589L; |
50 |
|
|
213 |
|
return m.keyIterator(); |
214 |
|
} |
215 |
|
|
235 |
– |
/* ---------------- Queue operations -------------- */ |
236 |
– |
|
237 |
– |
/** |
238 |
– |
* Adds the specified element, or fails if this element is already |
239 |
– |
* present. |
240 |
– |
* @param o the element to insert. |
241 |
– |
* @return <tt>true</tt> if it was possible to add the element, |
242 |
– |
* else <tt>false</tt> |
243 |
– |
*/ |
244 |
– |
public boolean offer(E o) { |
245 |
– |
return add(o); |
246 |
– |
} |
247 |
– |
|
248 |
– |
/** |
249 |
– |
* Retrieves and removes the first (lowest) element. |
250 |
– |
* |
251 |
– |
* @return the least element, or <tt>null</tt> if empty. |
252 |
– |
*/ |
253 |
– |
public E poll() { |
254 |
– |
return m.removeFirstKey(); |
255 |
– |
} |
256 |
– |
|
257 |
– |
/** |
258 |
– |
* Retrieves and removes the first (lowest) element. This method |
259 |
– |
* differs from the <tt>poll</tt> method in that it throws an |
260 |
– |
* exception if empty. |
261 |
– |
* |
262 |
– |
* @return the first (lowest) element. |
263 |
– |
* @throws NoSuchElementException if empty. |
264 |
– |
*/ |
265 |
– |
public E remove() { |
266 |
– |
E x = m.removeFirstKey(); |
267 |
– |
if (x == null) |
268 |
– |
throw new NoSuchElementException(); |
269 |
– |
return x; |
270 |
– |
} |
271 |
– |
|
272 |
– |
/** |
273 |
– |
* Retrieves, but does not remove, the first (lowest) element, |
274 |
– |
* returning <tt>null</tt> if empty. |
275 |
– |
* |
276 |
– |
* @return the first (lowest) element, or <tt>null</tt> if empty. |
277 |
– |
*/ |
278 |
– |
public E peek() { |
279 |
– |
return m.lowestKey(); |
280 |
– |
} |
281 |
– |
|
282 |
– |
/** |
283 |
– |
* Retrieves, but does not remove, the first (lowest) element. |
284 |
– |
* This method differs from the <tt>peek</tt> method only in that |
285 |
– |
* it throws an exception if empty. |
286 |
– |
* |
287 |
– |
* @return the first (lowest) element. |
288 |
– |
* @throws NoSuchElementException if empty. |
289 |
– |
*/ |
290 |
– |
public E element() { |
291 |
– |
return m.firstKey(); |
292 |
– |
} |
293 |
– |
|
216 |
|
/* ---------------- Relational operations -------------- */ |
217 |
|
|
218 |
|
/** |
275 |
|
return m.higherKey(o); |
276 |
|
} |
277 |
|
|
278 |
+ |
/** |
279 |
+ |
* Retrieves and removes the first (lowest) element. |
280 |
+ |
* |
281 |
+ |
* @return the least element, or <tt>null</tt> if empty. |
282 |
+ |
*/ |
283 |
+ |
public E pollFirst() { |
284 |
+ |
return m.removeFirstKey(); |
285 |
+ |
} |
286 |
+ |
|
287 |
+ |
/** |
288 |
+ |
* Retrieves and removes the last (highest) element. |
289 |
+ |
* |
290 |
+ |
* @return the last element, or <tt>null</tt> if empty. |
291 |
+ |
*/ |
292 |
+ |
public E pollLast() { |
293 |
+ |
return m.removeLastKey(); |
294 |
+ |
} |
295 |
+ |
|
296 |
+ |
|
297 |
|
/* ---------------- SortedSet operations -------------- */ |
298 |
|
|
299 |
|
|
349 |
|
* @throws NullPointerException if <tt>fromElement</tt> or |
350 |
|
* <tt>toElement</tt> is <tt>null</tt>. |
351 |
|
*/ |
352 |
< |
public ConcurrentSkipListSubSet<E> subSet(E fromElement, E toElement) { |
352 |
> |
public NavigableSet<E> subSet(E fromElement, E toElement) { |
353 |
|
return new ConcurrentSkipListSubSet<E>(m, fromElement, toElement); |
354 |
|
} |
355 |
|
|
366 |
|
* if <tt>toElement</tt> does not implement <tt>Comparable</tt>). |
367 |
|
* @throws NullPointerException if <tt>toElement</tt> is <tt>null</tt>. |
368 |
|
*/ |
369 |
< |
public ConcurrentSkipListSubSet<E> headSet(E toElement) { |
369 |
> |
public NavigableSet<E> headSet(E toElement) { |
370 |
|
return new ConcurrentSkipListSubSet<E>(m, null, toElement); |
371 |
|
} |
372 |
|
|
385 |
|
* <tt>Comparable</tt>). |
386 |
|
* @throws NullPointerException if <tt>fromElement</tt> is <tt>null</tt>. |
387 |
|
*/ |
388 |
< |
public ConcurrentSkipListSubSet<E> tailSet(E fromElement) { |
388 |
> |
public NavigableSet<E> tailSet(E fromElement) { |
389 |
|
return new ConcurrentSkipListSubSet<E>(m, fromElement, null); |
390 |
|
} |
391 |
+ |
|
392 |
+ |
/** |
393 |
+ |
* Subsets returned by {@link ConcurrentSkipListSet} subset operations |
394 |
+ |
* represent a subrange of elements of their underlying |
395 |
+ |
* sets. Instances of this class support all methods of their |
396 |
+ |
* underlying sets, differing in that elements outside their range are |
397 |
+ |
* ignored, and attempts to add elements outside their ranges result |
398 |
+ |
* in {@link IllegalArgumentException}. Instances of this class are |
399 |
+ |
* constructed only using the <tt>subSet</tt>, <tt>headSet</tt>, and |
400 |
+ |
* <tt>tailSet</tt> methods of their underlying sets. |
401 |
+ |
* |
402 |
+ |
*/ |
403 |
+ |
static class ConcurrentSkipListSubSet<E> |
404 |
+ |
extends AbstractSet<E> |
405 |
+ |
implements NavigableSet<E>, java.io.Serializable { |
406 |
+ |
|
407 |
+ |
private static final long serialVersionUID = -7647078645896651609L; |
408 |
+ |
|
409 |
+ |
/** The underlying submap */ |
410 |
+ |
private final ConcurrentSkipListMap.ConcurrentSkipListSubMap<E,Object> s; |
411 |
+ |
|
412 |
+ |
/** |
413 |
+ |
* Creates a new submap. |
414 |
+ |
* @param fromElement inclusive least value, or null if from start |
415 |
+ |
* @param toElement exclusive upper bound or null if to end |
416 |
+ |
* @throws IllegalArgumentException if fromElement and toElement |
417 |
+ |
* nonnull and fromElement greater than toElement |
418 |
+ |
*/ |
419 |
+ |
ConcurrentSkipListSubSet(ConcurrentSkipListMap<E,Object> map, |
420 |
+ |
E fromElement, E toElement) { |
421 |
+ |
s = new ConcurrentSkipListMap.ConcurrentSkipListSubMap<E,Object>(map, fromElement, |
422 |
+ |
toElement); |
423 |
+ |
} |
424 |
+ |
|
425 |
+ |
/** |
426 |
+ |
* Returns the number of elements in this set. If this set |
427 |
+ |
* contains more than <tt>Integer.MAX_VALUE</tt> elements, it |
428 |
+ |
* returns <tt>Integer.MAX_VALUE</tt>. |
429 |
+ |
* |
430 |
+ |
* <p>Beware that, unlike in most collections, this method is |
431 |
+ |
* <em>NOT</em> a constant-time operation. Because of the |
432 |
+ |
* asynchronous nature of these sets, determining the current |
433 |
+ |
* number of elements requires traversing them all to count them. |
434 |
+ |
* Additionally, it is possible for the size to change during |
435 |
+ |
* execution of this method, in which case the returned result |
436 |
+ |
* will be inaccurate. Thus, this method is typically not very |
437 |
+ |
* useful in concurrent applications. |
438 |
+ |
* |
439 |
+ |
* @return the number of elements in this set. |
440 |
+ |
*/ |
441 |
+ |
public int size() { |
442 |
+ |
return s.size(); |
443 |
+ |
} |
444 |
+ |
|
445 |
+ |
/** |
446 |
+ |
* Returns <tt>true</tt> if this set contains no elements. |
447 |
+ |
* @return <tt>true</tt> if this set contains no elements. |
448 |
+ |
*/ |
449 |
+ |
public boolean isEmpty() { |
450 |
+ |
return s.isEmpty(); |
451 |
+ |
} |
452 |
+ |
|
453 |
+ |
/** |
454 |
+ |
* Returns <tt>true</tt> if this set contains the specified |
455 |
+ |
* element. |
456 |
+ |
* |
457 |
+ |
* @param o the object to be checked for containment in this |
458 |
+ |
* set. |
459 |
+ |
* @return <tt>true</tt> if this set contains the specified |
460 |
+ |
* element. |
461 |
+ |
* |
462 |
+ |
* @throws ClassCastException if the specified object cannot |
463 |
+ |
* be compared with the elements currently in the set. |
464 |
+ |
* @throws NullPointerException if o is <tt>null</tt>. |
465 |
+ |
*/ |
466 |
+ |
public boolean contains(Object o) { |
467 |
+ |
return s.containsKey(o); |
468 |
+ |
} |
469 |
+ |
|
470 |
+ |
|
471 |
+ |
/** |
472 |
+ |
* Adds the specified element to this set if it is not already |
473 |
+ |
* present. |
474 |
+ |
* |
475 |
+ |
* @param o element to be added to this set. |
476 |
+ |
* @return <tt>true</tt> if the set did not already contain |
477 |
+ |
* the specified element. |
478 |
+ |
* |
479 |
+ |
* @throws ClassCastException if the specified object cannot |
480 |
+ |
* be compared with the elements currently in the set. |
481 |
+ |
* @throws IllegalArgumentException if o is outside the range |
482 |
+ |
* of this subset. |
483 |
+ |
* @throws NullPointerException if o is <tt>null</tt>. |
484 |
+ |
*/ |
485 |
+ |
public boolean add(E o) { |
486 |
+ |
return s.put(o, Boolean.TRUE) == null; |
487 |
+ |
} |
488 |
+ |
|
489 |
+ |
/** |
490 |
+ |
* Removes the specified element from this set if it is |
491 |
+ |
* present. |
492 |
+ |
* |
493 |
+ |
* @param o object to be removed from this set, if present. |
494 |
+ |
* @return <tt>true</tt> if the set contained the specified element. |
495 |
+ |
* |
496 |
+ |
* @throws ClassCastException if the specified object cannot |
497 |
+ |
* be compared with the elements currently in the set. |
498 |
+ |
* @throws NullPointerException if o is <tt>null</tt>. |
499 |
+ |
*/ |
500 |
+ |
public boolean remove(Object o) { |
501 |
+ |
return s.remove(o) != null; |
502 |
+ |
} |
503 |
+ |
|
504 |
+ |
/** |
505 |
+ |
* Removes all of the elements from this set. |
506 |
+ |
*/ |
507 |
+ |
public void clear() { |
508 |
+ |
s.clear(); |
509 |
+ |
} |
510 |
+ |
|
511 |
+ |
/** |
512 |
+ |
* Returns an iterator over the elements in this set. The elements |
513 |
+ |
* are returned in ascending order. |
514 |
+ |
* |
515 |
+ |
* @return an iterator over the elements in this set. |
516 |
+ |
*/ |
517 |
+ |
public Iterator<E> iterator() { |
518 |
+ |
return s.keySet().iterator(); |
519 |
+ |
} |
520 |
+ |
|
521 |
+ |
/** |
522 |
+ |
* Returns an element greater than or equal to the given |
523 |
+ |
* element, or null if there is no such element. |
524 |
+ |
* |
525 |
+ |
* @param o the value to match |
526 |
+ |
* @return an element greater than or equal to given element, or null |
527 |
+ |
* if there is no such element. |
528 |
+ |
* @throws ClassCastException if o cannot be compared with the |
529 |
+ |
* elements currently in the set. |
530 |
+ |
* @throws NullPointerException if o is <tt>null</tt> |
531 |
+ |
*/ |
532 |
+ |
public E ceiling(E o) { |
533 |
+ |
E key = o; |
534 |
+ |
E least = s.getLeast(); |
535 |
+ |
if (least != null && s.getMap().compare(o, least) < 0) |
536 |
+ |
key = least; |
537 |
+ |
E k = s.getMap().ceilingKey(key); |
538 |
+ |
return (k != null && s.inHalfOpenRange(k))? k : null; |
539 |
+ |
} |
540 |
+ |
|
541 |
+ |
/** |
542 |
+ |
* Returns an element strictly less than the given element, or null if |
543 |
+ |
* there is no such element. |
544 |
+ |
* |
545 |
+ |
* @param o the value to match |
546 |
+ |
* @return the greatest element less than the given element, or |
547 |
+ |
* null if there is no such element. |
548 |
+ |
* @throws ClassCastException if o cannot be compared with the |
549 |
+ |
* elements currently in the set. |
550 |
+ |
* @throws NullPointerException if o is <tt>null</tt>. |
551 |
+ |
*/ |
552 |
+ |
public E lower(E o) { |
553 |
+ |
E k = s.getMap().lowerKey(o); |
554 |
+ |
return (k != null && s.inHalfOpenRange(k))? k : null; |
555 |
+ |
} |
556 |
+ |
|
557 |
+ |
/** |
558 |
+ |
* Returns an element less than or equal to the given element, or null |
559 |
+ |
* if there is no such element. |
560 |
+ |
* |
561 |
+ |
* @param o the value to match |
562 |
+ |
* @return the greatest element less than or equal to given |
563 |
+ |
* element, or null if there is no such element. |
564 |
+ |
* @throws ClassCastException if o cannot be compared with the |
565 |
+ |
* elements currently in the set. |
566 |
+ |
* @throws NullPointerException if o is <tt>null</tt>. |
567 |
+ |
*/ |
568 |
+ |
public E floor(E o) { |
569 |
+ |
E k = s.getMap().floorKey(o); |
570 |
+ |
return (k != null && s.inHalfOpenRange(k))? k : null; |
571 |
+ |
} |
572 |
+ |
|
573 |
+ |
/** |
574 |
+ |
* Returns an element strictly greater than the given element, or null |
575 |
+ |
* if there is no such element. |
576 |
+ |
* |
577 |
+ |
* @param o the value to match |
578 |
+ |
* @return the least element greater than the given element, or |
579 |
+ |
* null if there is no such element. |
580 |
+ |
* @throws ClassCastException if o cannot be compared with the |
581 |
+ |
* elements currently in the set. |
582 |
+ |
* @throws NullPointerException if o is <tt>null</tt>. |
583 |
+ |
*/ |
584 |
+ |
public E higher(E o) { |
585 |
+ |
E k; |
586 |
+ |
E least = s.getLeast(); |
587 |
+ |
if (least != null && s.getMap().compare(o, least) < 0) |
588 |
+ |
k = s.getMap().ceilingKey(least); |
589 |
+ |
else |
590 |
+ |
k = s.getMap().higherKey(o); |
591 |
+ |
return (k != null && s.inHalfOpenRange(k))? k : null; |
592 |
+ |
} |
593 |
+ |
|
594 |
+ |
/** |
595 |
+ |
* Retrieves and removes the first (lowest) element. |
596 |
+ |
* |
597 |
+ |
* @return the first element, or <tt>null</tt> if empty. |
598 |
+ |
*/ |
599 |
+ |
public E pollFirst() { |
600 |
+ |
for (;;) { |
601 |
+ |
E k = s.lowestKey(); |
602 |
+ |
if (k == null) |
603 |
+ |
return null; |
604 |
+ |
if (remove(k)) |
605 |
+ |
return k; |
606 |
+ |
} |
607 |
+ |
} |
608 |
+ |
|
609 |
+ |
/** |
610 |
+ |
* Retrieves and removes the last (highest) element. |
611 |
+ |
* |
612 |
+ |
* @return the last element, or <tt>null</tt> if empty. |
613 |
+ |
*/ |
614 |
+ |
public E pollLast() { |
615 |
+ |
for (;;) { |
616 |
+ |
E k = s.highestKey(); |
617 |
+ |
if (k == null) |
618 |
+ |
return null; |
619 |
+ |
if (remove(k)) |
620 |
+ |
return k; |
621 |
+ |
} |
622 |
+ |
} |
623 |
+ |
|
624 |
+ |
/** |
625 |
+ |
* Returns the comparator used to order this set, or <tt>null</tt> |
626 |
+ |
* if this set uses its elements natural ordering. |
627 |
+ |
* |
628 |
+ |
* @return the comparator used to order this set, or <tt>null</tt> |
629 |
+ |
* if this set uses its elements natural ordering. |
630 |
+ |
*/ |
631 |
+ |
public Comparator<? super E> comparator() { |
632 |
+ |
return s.comparator(); |
633 |
+ |
} |
634 |
+ |
|
635 |
+ |
/** |
636 |
+ |
* Returns the first (lowest) element currently in this set. |
637 |
+ |
* |
638 |
+ |
* @return the first (lowest) element currently in this set. |
639 |
+ |
* @throws NoSuchElementException sorted set is empty. |
640 |
+ |
*/ |
641 |
+ |
public E first() { |
642 |
+ |
return s.firstKey(); |
643 |
+ |
} |
644 |
+ |
|
645 |
+ |
/** |
646 |
+ |
* Returns the last (highest) element currently in this set. |
647 |
+ |
* |
648 |
+ |
* @return the last (highest) element currently in this set. |
649 |
+ |
* @throws NoSuchElementException sorted set is empty. |
650 |
+ |
*/ |
651 |
+ |
public E last() { |
652 |
+ |
return s.lastKey(); |
653 |
+ |
} |
654 |
+ |
|
655 |
+ |
/** |
656 |
+ |
* Returns a view of the portion of this set whose elements |
657 |
+ |
* range from <tt>fromElement</tt>, inclusive, to |
658 |
+ |
* <tt>toElement</tt>, exclusive. (If <tt>fromElement</tt> |
659 |
+ |
* and <tt>toElement</tt> are equal, the returned sorted set |
660 |
+ |
* is empty.) The returned sorted set is backed by this set, |
661 |
+ |
* so changes in the returned sorted set are reflected in this |
662 |
+ |
* set, and vice-versa. |
663 |
+ |
* @param fromElement low endpoint (inclusive) of the subSet. |
664 |
+ |
* @param toElement high endpoint (exclusive) of the subSet. |
665 |
+ |
* @return a view of the portion of this set whose elements |
666 |
+ |
* range from <tt>fromElement</tt>, inclusive, to |
667 |
+ |
* <tt>toElement</tt>, exclusive. |
668 |
+ |
* @throws ClassCastException if <tt>fromElement</tt> and |
669 |
+ |
* <tt>toElement</tt> cannot be compared to one another using |
670 |
+ |
* this set's comparator (or, if the set has no comparator, |
671 |
+ |
* using natural ordering). |
672 |
+ |
* @throws IllegalArgumentException if <tt>fromElement</tt> is |
673 |
+ |
* greater than <tt>toElement</tt> or either key is outside |
674 |
+ |
* the range of this set. |
675 |
+ |
* @throws NullPointerException if <tt>fromElement</tt> or |
676 |
+ |
* <tt>toElement</tt> is <tt>null</tt>. |
677 |
+ |
*/ |
678 |
+ |
public NavigableSet<E> subSet(E fromElement, |
679 |
+ |
E toElement) { |
680 |
+ |
if (!s.inOpenRange(fromElement) || !s.inOpenRange(toElement)) |
681 |
+ |
throw new IllegalArgumentException("element out of range"); |
682 |
+ |
return new ConcurrentSkipListSubSet<E>(s.getMap(), |
683 |
+ |
fromElement, toElement); |
684 |
+ |
} |
685 |
+ |
|
686 |
+ |
/** |
687 |
+ |
* Returns a view of the portion of this set whose elements are |
688 |
+ |
* strictly less than <tt>toElement</tt>. The returned sorted set |
689 |
+ |
* is backed by this set, so changes in the returned sorted set |
690 |
+ |
* are reflected in this set, and vice-versa. |
691 |
+ |
* @param toElement high endpoint (exclusive) of the headSet. |
692 |
+ |
* @return a view of the portion of this set whose elements |
693 |
+ |
* are strictly less than toElement. |
694 |
+ |
* @throws ClassCastException if <tt>toElement</tt> is not |
695 |
+ |
* compatible with this set's comparator (or, if the set has |
696 |
+ |
* no comparator, if <tt>toElement</tt> does not implement |
697 |
+ |
* <tt>Comparable</tt>). |
698 |
+ |
* @throws IllegalArgumentException if <tt>toElement</tt> is |
699 |
+ |
* outside the range of this set. |
700 |
+ |
* @throws NullPointerException if <tt>toElement</tt> is |
701 |
+ |
* <tt>null</tt>. |
702 |
+ |
*/ |
703 |
+ |
public NavigableSet<E> headSet(E toElement) { |
704 |
+ |
E least = s.getLeast(); |
705 |
+ |
if (!s.inOpenRange(toElement)) |
706 |
+ |
throw new IllegalArgumentException("element out of range"); |
707 |
+ |
return new ConcurrentSkipListSubSet<E>(s.getMap(), |
708 |
+ |
least, toElement); |
709 |
+ |
} |
710 |
+ |
|
711 |
+ |
/** |
712 |
+ |
* Returns a view of the portion of this set whose elements |
713 |
+ |
* are greater than or equal to <tt>fromElement</tt>. The |
714 |
+ |
* returned sorted set is backed by this set, so changes in |
715 |
+ |
* the returned sorted set are reflected in this set, and |
716 |
+ |
* vice-versa. |
717 |
+ |
* @param fromElement low endpoint (inclusive) of the tailSet. |
718 |
+ |
* @return a view of the portion of this set whose elements |
719 |
+ |
* are greater than or equal to <tt>fromElement</tt>. |
720 |
+ |
* @throws ClassCastException if <tt>fromElement</tt> is not |
721 |
+ |
* compatible with this set's comparator (or, if the set has |
722 |
+ |
* no comparator, if <tt>fromElement</tt> does not implement |
723 |
+ |
* <tt>Comparable</tt>). |
724 |
+ |
* @throws IllegalArgumentException if <tt>fromElement</tt> is |
725 |
+ |
* outside the range of this set. |
726 |
+ |
* @throws NullPointerException if <tt>fromElement</tt> is |
727 |
+ |
* <tt>null</tt>. |
728 |
+ |
*/ |
729 |
+ |
public NavigableSet<E> tailSet(E fromElement) { |
730 |
+ |
E fence = s.getFence(); |
731 |
+ |
if (!s.inOpenRange(fromElement)) |
732 |
+ |
throw new IllegalArgumentException("element out of range"); |
733 |
+ |
return new ConcurrentSkipListSubSet<E>(s.getMap(), |
734 |
+ |
fromElement, fence); |
735 |
+ |
} |
736 |
+ |
} |
737 |
+ |
|
738 |
+ |
|
739 |
|
} |