| 538 |
|
* order that elements would be dequeued (via successive calls to |
| 539 |
|
* {@link #remove} or popped (via successive calls to {@link #pop}). |
| 540 |
|
* |
| 541 |
< |
* @return an <tt>Iterator</tt> over the elements in this deque |
| 541 |
> |
* @return an iterator over the elements in this deque |
| 542 |
|
*/ |
| 543 |
|
public Iterator<E> iterator() { |
| 544 |
|
return new DeqIterator(); |
| 545 |
|
} |
| 546 |
|
|
| 547 |
– |
/** |
| 548 |
– |
* Returns an iterator over the elements in this deque in reverse |
| 549 |
– |
* sequential order. The elements will be returned in order from |
| 550 |
– |
* last (tail) to first (head). |
| 551 |
– |
* |
| 552 |
– |
* @return an iterator over the elements in this deque in reverse |
| 553 |
– |
* sequence |
| 554 |
– |
*/ |
| 547 |
|
public Iterator<E> descendingIterator() { |
| 548 |
|
return new DescendingIterator(); |
| 549 |
|
} |
| 586 |
|
public void remove() { |
| 587 |
|
if (lastRet < 0) |
| 588 |
|
throw new IllegalStateException(); |
| 589 |
< |
if (delete(lastRet)) |
| 590 |
< |
cursor--; |
| 589 |
> |
if (delete(lastRet)) // if left-shifted, undo increment in next() |
| 590 |
> |
cursor = (cursor - 1) & (elements.length - 1); |
| 591 |
|
lastRet = -1; |
| 592 |
|
fence = tail; |
| 593 |
|
} |
| 595 |
|
|
| 596 |
|
|
| 597 |
|
private class DescendingIterator implements Iterator<E> { |
| 598 |
< |
/* |
| 599 |
< |
* This class is nearly a mirror-image of DeqIterator. It |
| 600 |
< |
* shares the same structure, but not many actual lines of |
| 601 |
< |
* code. The only asymmetric part is that to simplify some |
| 602 |
< |
* checks, indices are anded with length mask only on array |
| 603 |
< |
* access rather than on each update. |
| 598 |
> |
/* |
| 599 |
> |
* This class is nearly a mirror-image of DeqIterator, using |
| 600 |
> |
* (tail-1) instead of head for initial cursor, (head-1) |
| 601 |
> |
* instead of tail for fence, and elements.length instead of -1 |
| 602 |
> |
* for sentinel. It shares the same structure, but not many |
| 603 |
> |
* actual lines of code. |
| 604 |
|
*/ |
| 605 |
< |
private int cursor = tail - 1; |
| 606 |
< |
private int fence = head - 1; |
| 605 |
> |
private int cursor = (tail - 1) & (elements.length - 1); |
| 606 |
> |
private int fence = (head - 1) & (elements.length - 1); |
| 607 |
|
private int lastRet = elements.length; |
| 608 |
|
|
| 609 |
|
public boolean hasNext() { |
| 614 |
|
E result; |
| 615 |
|
if (cursor == fence) |
| 616 |
|
throw new NoSuchElementException(); |
| 617 |
< |
if ((head - 1) != fence || |
| 618 |
< |
(result = elements[cursor & (elements.length-1)]) == null) |
| 617 |
> |
if (((head - 1) & (elements.length - 1)) != fence || |
| 618 |
> |
(result = elements[cursor]) == null) |
| 619 |
|
throw new ConcurrentModificationException(); |
| 620 |
|
lastRet = cursor; |
| 621 |
< |
cursor--; |
| 621 |
> |
cursor = (cursor - 1) & (elements.length - 1); |
| 622 |
|
return result; |
| 623 |
|
} |
| 624 |
|
|
| 625 |
|
public void remove() { |
| 626 |
|
if (lastRet >= elements.length) |
| 627 |
|
throw new IllegalStateException(); |
| 628 |
< |
if (delete(lastRet & (elements.length-1))) |
| 629 |
< |
cursor++; |
| 628 |
> |
if (!delete(lastRet)) |
| 629 |
> |
cursor = (cursor + 1) & (elements.length - 1); |
| 630 |
|
lastRet = elements.length; |
| 631 |
< |
fence = head - 1; |
| 631 |
> |
fence = (head - 1) & (elements.length - 1); |
| 632 |
|
} |
| 633 |
|
} |
| 634 |
|
|
| 790 |
|
s.defaultWriteObject(); |
| 791 |
|
|
| 792 |
|
// Write out size |
| 793 |
< |
int size = size(); |
| 802 |
< |
s.writeInt(size); |
| 793 |
> |
s.writeInt(size()); |
| 794 |
|
|
| 795 |
|
// Write out elements in order. |
| 805 |
– |
int i = head; |
| 796 |
|
int mask = elements.length - 1; |
| 797 |
< |
for (int j = 0; j < size; j++) { |
| 797 |
> |
for (int i = head; i != tail; i = (i + 1) & mask) |
| 798 |
|
s.writeObject(elements[i]); |
| 809 |
– |
i = (i + 1) & mask; |
| 810 |
– |
} |
| 799 |
|
} |
| 800 |
|
|
| 801 |
|
/** |
