93 |
|
private void grow(int needed) { |
94 |
|
// overflow-conscious code |
95 |
|
// checkInvariants(); |
96 |
< |
int oldCapacity = elements.length; |
96 |
> |
final int oldCapacity = elements.length; |
97 |
|
int newCapacity; |
98 |
|
// Double size if small; else grow by 50% |
99 |
|
int jump = (oldCapacity < 64) ? (oldCapacity + 2) : (oldCapacity >> 1); |
115 |
|
|
116 |
|
/** Capacity calculation for edge conditions, especially overflow. */ |
117 |
|
private int newCapacity(int needed, int jump) { |
118 |
< |
int oldCapacity = elements.length; |
119 |
< |
int minCapacity; |
118 |
> |
final int oldCapacity = elements.length, minCapacity; |
119 |
|
if ((minCapacity = oldCapacity + needed) - MAX_ARRAY_SIZE > 0) { |
120 |
|
if (minCapacity < 0) |
121 |
|
throw new IllegalStateException("Sorry, deque too big"); |
133 |
|
* to ensure that it can hold at least the given number of elements. |
134 |
|
* |
135 |
|
* @param minCapacity the desired minimum capacity |
136 |
< |
* @since 9 |
136 |
> |
* @since TBD |
137 |
|
*/ |
138 |
< |
public void ensureCapacity(int minCapacity) { |
138 |
> |
/* public */ void ensureCapacity(int minCapacity) { |
139 |
|
if (minCapacity > elements.length) |
140 |
|
grow(minCapacity - elements.length); |
141 |
|
// checkInvariants(); |
144 |
|
/** |
145 |
|
* Minimizes the internal storage of this collection. |
146 |
|
* |
147 |
< |
* @since 9 |
147 |
> |
* @since TBD |
148 |
|
*/ |
149 |
< |
public void trimToSize() { |
149 |
> |
/* public */ void trimToSize() { |
150 |
|
if (size < elements.length) { |
151 |
|
elements = toArray(); |
152 |
|
head = 0; |
183 |
|
* @throws NullPointerException if the specified collection is null |
184 |
|
*/ |
185 |
|
public ArrayDeque(Collection<? extends E> c) { |
186 |
< |
Object[] elements = c.toArray(); |
186 |
> |
Object[] es = c.toArray(); |
187 |
|
// defend against c.toArray (incorrectly) not returning Object[] |
188 |
|
// (see e.g. https://bugs.openjdk.java.net/browse/JDK-6260652) |
189 |
< |
if (elements.getClass() != Object[].class) |
190 |
< |
elements = Arrays.copyOf(elements, size, Object[].class); |
191 |
< |
for (Object obj : elements) |
189 |
> |
if (es.getClass() != Object[].class) |
190 |
> |
es = Arrays.copyOf(es, es.length, Object[].class); |
191 |
> |
for (Object obj : es) |
192 |
|
Objects.requireNonNull(obj); |
193 |
< |
size = elements.length; |
194 |
< |
this.elements = elements; |
193 |
> |
this.elements = es; |
194 |
> |
this.size = es.length; |
195 |
|
} |
196 |
|
|
197 |
|
/** |
198 |
< |
* Returns the array index of the last element. |
199 |
< |
* May return invalid index -1 if there are no elements. |
198 |
> |
* Increments i, mod modulus. |
199 |
> |
* Precondition and postcondition: 0 <= i < modulus. |
200 |
|
*/ |
201 |
< |
final int tail() { |
202 |
< |
return add(head, size - 1, elements.length); |
201 |
> |
static final int inc(int i, int modulus) { |
202 |
> |
if (++i >= modulus) i = 0; |
203 |
> |
return i; |
204 |
|
} |
205 |
|
|
206 |
|
/** |
207 |
< |
* Adds i and j, mod modulus. |
208 |
< |
* Precondition and postcondition: 0 <= i < modulus, 0 <= j <= modulus. |
207 |
> |
* Decrements i, mod modulus. |
208 |
> |
* Precondition and postcondition: 0 <= i < modulus. |
209 |
|
*/ |
210 |
< |
static final int add(int i, int j, int modulus) { |
211 |
< |
if ((i += j) - modulus >= 0) i -= modulus; |
210 |
> |
static final int dec(int i, int modulus) { |
211 |
> |
if (--i < 0) i = modulus - 1; |
212 |
|
return i; |
213 |
|
} |
214 |
|
|
215 |
|
/** |
216 |
< |
* Increments i, mod modulus. |
217 |
< |
* Precondition and postcondition: 0 <= i < modulus. |
216 |
> |
* Adds i and j, mod modulus. |
217 |
> |
* Precondition and postcondition: 0 <= i < modulus, 0 <= j <= modulus. |
218 |
|
*/ |
219 |
< |
static final int inc(int i, int modulus) { |
220 |
< |
if (++i == modulus) i = 0; |
219 |
> |
static final int add(int i, int j, int modulus) { |
220 |
> |
if ((i += j) - modulus >= 0) i -= modulus; |
221 |
|
return i; |
222 |
|
} |
223 |
|
|
224 |
|
/** |
225 |
< |
* Decrements i, mod modulus. |
226 |
< |
* Precondition and postcondition: 0 <= i < modulus. |
225 |
> |
* Returns the array index of the last element. |
226 |
> |
* May return invalid index -1 if there are no elements. |
227 |
|
*/ |
228 |
< |
static final int dec(int i, int modulus) { |
229 |
< |
if (--i < 0) i += modulus; |
230 |
< |
return i; |
228 |
> |
final int tail() { |
229 |
> |
return add(head, size - 1, elements.length); |
230 |
|
} |
231 |
|
|
232 |
|
/** |
233 |
|
* Returns element at array index i. |
234 |
|
*/ |
235 |
|
@SuppressWarnings("unchecked") |
236 |
< |
final E elementAt(int i) { |
236 |
> |
private E elementAt(int i) { |
237 |
|
return (E) elements[i]; |
238 |
|
} |
239 |
|
|
240 |
|
/** |
241 |
|
* A version of elementAt that checks for null elements. |
242 |
|
* This check doesn't catch all possible comodifications, |
243 |
< |
* but does catch ones that corrupt traversal. |
243 |
> |
* but does catch ones that corrupt traversal. It's a little |
244 |
> |
* surprising that javac allows this abuse of generics. |
245 |
|
*/ |
246 |
< |
E checkedElementAt(Object[] elements, int i) { |
247 |
< |
@SuppressWarnings("unchecked") E e = (E) elements[i]; |
246 |
> |
static final <E> E nonNullElementAt(Object[] es, int i) { |
247 |
> |
@SuppressWarnings("unchecked") E e = (E) es[i]; |
248 |
|
if (e == null) |
249 |
|
throw new ConcurrentModificationException(); |
250 |
|
return e; |
263 |
|
public void addFirst(E e) { |
264 |
|
// checkInvariants(); |
265 |
|
Objects.requireNonNull(e); |
266 |
< |
Object[] elements; |
267 |
< |
int capacity, s = size; |
268 |
< |
while (s == (capacity = (elements = this.elements).length)) |
266 |
> |
Object[] es; |
267 |
> |
int capacity, h; |
268 |
> |
final int s; |
269 |
> |
if ((s = size) == (capacity = (es = elements).length)) { |
270 |
|
grow(1); |
271 |
< |
elements[head = dec(head, capacity)] = e; |
271 |
> |
capacity = (es = elements).length; |
272 |
> |
} |
273 |
> |
if ((h = head - 1) < 0) h = capacity - 1; |
274 |
> |
es[head = h] = e; |
275 |
|
size = s + 1; |
276 |
+ |
// checkInvariants(); |
277 |
|
} |
278 |
|
|
279 |
|
/** |
287 |
|
public void addLast(E e) { |
288 |
|
// checkInvariants(); |
289 |
|
Objects.requireNonNull(e); |
290 |
< |
Object[] elements; |
291 |
< |
int capacity, s = size; |
292 |
< |
while (s == (capacity = (elements = this.elements).length)) |
290 |
> |
Object[] es; |
291 |
> |
int capacity; |
292 |
> |
final int s; |
293 |
> |
if ((s = size) == (capacity = (es = elements).length)) { |
294 |
|
grow(1); |
295 |
< |
elements[add(head, s, capacity)] = e; |
295 |
> |
capacity = (es = elements).length; |
296 |
> |
} |
297 |
> |
es[add(head, s, capacity)] = e; |
298 |
|
size = s + 1; |
299 |
+ |
// checkInvariants(); |
300 |
|
} |
301 |
|
|
302 |
|
/** |
310 |
|
* @throws NullPointerException if the specified collection or any |
311 |
|
* of its elements are null |
312 |
|
*/ |
304 |
– |
@Override |
313 |
|
public boolean addAll(Collection<? extends E> c) { |
314 |
+ |
final int s = size, needed = c.size() - (elements.length - s); |
315 |
+ |
if (needed > 0) |
316 |
+ |
grow(needed); |
317 |
+ |
c.forEach((e) -> addLast(e)); |
318 |
|
// checkInvariants(); |
319 |
< |
Object[] a, elements; |
308 |
< |
int len, capacity, s = size; |
309 |
< |
if ((len = (a = c.toArray()).length) == 0) |
310 |
< |
return false; |
311 |
< |
while ((capacity = (elements = this.elements).length) - s < len) |
312 |
< |
grow(len - (capacity - s)); |
313 |
< |
int i = add(head, s, capacity); |
314 |
< |
for (Object x : a) { |
315 |
< |
Objects.requireNonNull(x); |
316 |
< |
elements[i] = x; |
317 |
< |
i = inc(i, capacity); |
318 |
< |
size++; |
319 |
< |
} |
320 |
< |
return true; |
319 |
> |
return size > s; |
320 |
|
} |
321 |
|
|
322 |
|
/** |
348 |
|
*/ |
349 |
|
public E removeFirst() { |
350 |
|
// checkInvariants(); |
351 |
< |
E x = pollFirst(); |
352 |
< |
if (x == null) |
351 |
> |
E e = pollFirst(); |
352 |
> |
if (e == null) |
353 |
|
throw new NoSuchElementException(); |
354 |
< |
return x; |
354 |
> |
return e; |
355 |
|
} |
356 |
|
|
357 |
|
/** |
359 |
|
*/ |
360 |
|
public E removeLast() { |
361 |
|
// checkInvariants(); |
362 |
< |
E x = pollLast(); |
363 |
< |
if (x == null) |
362 |
> |
E e = pollLast(); |
363 |
> |
if (e == null) |
364 |
|
throw new NoSuchElementException(); |
365 |
< |
return x; |
365 |
> |
return e; |
366 |
|
} |
367 |
|
|
368 |
|
public E pollFirst() { |
369 |
|
// checkInvariants(); |
370 |
< |
final int s, h; |
371 |
< |
if ((s = size) == 0) |
370 |
> |
int s, h; |
371 |
> |
if ((s = size) <= 0) |
372 |
|
return null; |
373 |
< |
final Object[] elements = this.elements; |
374 |
< |
@SuppressWarnings("unchecked") E e = (E) elements[h = head]; |
375 |
< |
elements[h] = null; |
376 |
< |
head = inc(h, elements.length); |
373 |
> |
final Object[] es = elements; |
374 |
> |
@SuppressWarnings("unchecked") E e = (E) es[h = head]; |
375 |
> |
es[h] = null; |
376 |
> |
if (++h >= es.length) h = 0; |
377 |
> |
head = h; |
378 |
|
size = s - 1; |
379 |
|
return e; |
380 |
|
} |
382 |
|
public E pollLast() { |
383 |
|
// checkInvariants(); |
384 |
|
final int s, tail; |
385 |
< |
if ((s = size) == 0) |
385 |
> |
if ((s = size) <= 0) |
386 |
|
return null; |
387 |
< |
final Object[] elements = this.elements; |
387 |
> |
final Object[] es = elements; |
388 |
|
@SuppressWarnings("unchecked") |
389 |
< |
E e = (E) elements[tail = add(head, s - 1, elements.length)]; |
390 |
< |
elements[tail] = null; |
389 |
> |
E e = (E) es[tail = add(head, s - 1, es.length)]; |
390 |
> |
es[tail] = null; |
391 |
|
size = s - 1; |
392 |
|
return e; |
393 |
|
} |
397 |
|
*/ |
398 |
|
public E getFirst() { |
399 |
|
// checkInvariants(); |
400 |
< |
if (size == 0) throw new NoSuchElementException(); |
400 |
> |
if (size <= 0) throw new NoSuchElementException(); |
401 |
|
return elementAt(head); |
402 |
|
} |
403 |
|
|
404 |
|
/** |
405 |
|
* @throws NoSuchElementException {@inheritDoc} |
406 |
|
*/ |
407 |
+ |
@SuppressWarnings("unchecked") |
408 |
|
public E getLast() { |
409 |
|
// checkInvariants(); |
410 |
< |
if (size == 0) throw new NoSuchElementException(); |
411 |
< |
return elementAt(tail()); |
410 |
> |
final int s; |
411 |
> |
if ((s = size) <= 0) throw new NoSuchElementException(); |
412 |
> |
final Object[] es = elements; |
413 |
> |
return (E) es[add(head, s - 1, es.length)]; |
414 |
|
} |
415 |
|
|
416 |
|
public E peekFirst() { |
417 |
|
// checkInvariants(); |
418 |
< |
return (size == 0) ? null : elementAt(head); |
418 |
> |
return (size <= 0) ? null : elementAt(head); |
419 |
|
} |
420 |
|
|
421 |
+ |
@SuppressWarnings("unchecked") |
422 |
|
public E peekLast() { |
423 |
|
// checkInvariants(); |
424 |
< |
return (size == 0) ? null : elementAt(tail()); |
424 |
> |
final int s; |
425 |
> |
if ((s = size) <= 0) return null; |
426 |
> |
final Object[] es = elements; |
427 |
> |
return (E) es[add(head, s - 1, es.length)]; |
428 |
|
} |
429 |
|
|
430 |
|
/** |
440 |
|
* @return {@code true} if the deque contained the specified element |
441 |
|
*/ |
442 |
|
public boolean removeFirstOccurrence(Object o) { |
436 |
– |
// checkInvariants(); |
443 |
|
if (o != null) { |
444 |
< |
final Object[] elements = this.elements; |
445 |
< |
final int capacity = elements.length; |
446 |
< |
for (int k = size, i = head; --k >= 0; i = inc(i, capacity)) { |
447 |
< |
if (o.equals(elements[i])) { |
448 |
< |
delete(i); |
449 |
< |
return true; |
450 |
< |
} |
444 |
> |
final Object[] es = elements; |
445 |
> |
int i, end, to, todo; |
446 |
> |
todo = (end = (i = head) + size) |
447 |
> |
- (to = (es.length - end >= 0) ? end : es.length); |
448 |
> |
for (;; to = todo, todo = 0, i = 0) { |
449 |
> |
for (; i < to; i++) |
450 |
> |
if (o.equals(es[i])) { |
451 |
> |
delete(i); |
452 |
> |
return true; |
453 |
> |
} |
454 |
> |
if (todo == 0) break; |
455 |
|
} |
456 |
|
} |
457 |
|
return false; |
471 |
|
*/ |
472 |
|
public boolean removeLastOccurrence(Object o) { |
473 |
|
if (o != null) { |
474 |
< |
final Object[] elements = this.elements; |
475 |
< |
final int capacity = elements.length; |
476 |
< |
for (int k = size, i = add(head, k - 1, capacity); |
477 |
< |
--k >= 0; i = dec(i, capacity)) { |
478 |
< |
if (o.equals(elements[i])) { |
479 |
< |
delete(i); |
480 |
< |
return true; |
481 |
< |
} |
474 |
> |
final Object[] es = elements; |
475 |
> |
int i, to, end, todo; |
476 |
> |
todo = (to = ((end = (i = tail()) - size) >= -1) ? end : -1) - end; |
477 |
> |
for (;; to = (i = es.length - 1) - todo, todo = 0) { |
478 |
> |
for (; i > to; i--) |
479 |
> |
if (o.equals(es[i])) { |
480 |
> |
delete(i); |
481 |
> |
return true; |
482 |
> |
} |
483 |
> |
if (todo == 0) break; |
484 |
|
} |
485 |
|
} |
486 |
|
return false; |
612 |
|
*/ |
613 |
|
boolean delete(int i) { |
614 |
|
// checkInvariants(); |
615 |
< |
final Object[] elements = this.elements; |
616 |
< |
final int capacity = elements.length; |
615 |
> |
final Object[] es = elements; |
616 |
> |
final int capacity = es.length; |
617 |
|
final int h = head; |
618 |
|
int front; // number of elements before to-be-deleted elt |
619 |
|
if ((front = i - h) < 0) front += capacity; |
621 |
|
if (front < back) { |
622 |
|
// move front elements forwards |
623 |
|
if (h <= i) { |
624 |
< |
System.arraycopy(elements, h, elements, h + 1, front); |
624 |
> |
System.arraycopy(es, h, es, h + 1, front); |
625 |
|
} else { // Wrap around |
626 |
< |
System.arraycopy(elements, 0, elements, 1, i); |
627 |
< |
elements[0] = elements[capacity - 1]; |
628 |
< |
System.arraycopy(elements, h, elements, h + 1, front - (i + 1)); |
626 |
> |
System.arraycopy(es, 0, es, 1, i); |
627 |
> |
es[0] = es[capacity - 1]; |
628 |
> |
System.arraycopy(es, h, es, h + 1, front - (i + 1)); |
629 |
|
} |
630 |
< |
elements[h] = null; |
631 |
< |
head = inc(h, capacity); |
630 |
> |
es[h] = null; |
631 |
> |
if ((head = (h + 1)) >= capacity) head = 0; |
632 |
|
size--; |
633 |
|
// checkInvariants(); |
634 |
|
return false; |
636 |
|
// move back elements backwards |
637 |
|
int tail = tail(); |
638 |
|
if (i <= tail) { |
639 |
< |
System.arraycopy(elements, i + 1, elements, i, back); |
639 |
> |
System.arraycopy(es, i + 1, es, i, back); |
640 |
|
} else { // Wrap around |
641 |
|
int firstLeg = capacity - (i + 1); |
642 |
< |
System.arraycopy(elements, i + 1, elements, i, firstLeg); |
643 |
< |
elements[capacity - 1] = elements[0]; |
644 |
< |
System.arraycopy(elements, 1, elements, 0, back - firstLeg - 1); |
642 |
> |
System.arraycopy(es, i + 1, es, i, firstLeg); |
643 |
> |
es[capacity - 1] = es[0]; |
644 |
> |
System.arraycopy(es, 1, es, 0, back - firstLeg - 1); |
645 |
|
} |
646 |
< |
elements[tail] = null; |
646 |
> |
es[tail] = null; |
647 |
|
size--; |
648 |
|
// checkInvariants(); |
649 |
|
return true; |
701 |
|
|
702 |
|
DeqIterator() { cursor = head; } |
703 |
|
|
692 |
– |
int advance(int i, int modulus) { |
693 |
– |
return inc(i, modulus); |
694 |
– |
} |
695 |
– |
|
696 |
– |
void doRemove() { |
697 |
– |
if (delete(lastRet)) |
698 |
– |
// if left-shifted, undo advance in next() |
699 |
– |
cursor = dec(cursor, elements.length); |
700 |
– |
} |
701 |
– |
|
704 |
|
public final boolean hasNext() { |
705 |
|
return remaining > 0; |
706 |
|
} |
707 |
|
|
708 |
< |
public final E next() { |
709 |
< |
if (remaining == 0) |
708 |
> |
public E next() { |
709 |
> |
if (remaining <= 0) |
710 |
|
throw new NoSuchElementException(); |
711 |
< |
E e = checkedElementAt(elements, cursor); |
711 |
> |
final Object[] es = elements; |
712 |
> |
E e = nonNullElementAt(es, cursor); |
713 |
|
lastRet = cursor; |
714 |
< |
cursor = advance(cursor, elements.length); |
714 |
> |
if (++cursor >= es.length) cursor = 0; |
715 |
|
remaining--; |
716 |
|
return e; |
717 |
|
} |
718 |
|
|
719 |
+ |
void postDelete(boolean leftShifted) { |
720 |
+ |
if (leftShifted) |
721 |
+ |
if (--cursor < 0) cursor = elements.length - 1; |
722 |
+ |
} |
723 |
+ |
|
724 |
|
public final void remove() { |
725 |
|
if (lastRet < 0) |
726 |
|
throw new IllegalStateException(); |
727 |
< |
doRemove(); |
727 |
> |
postDelete(delete(lastRet)); |
728 |
|
lastRet = -1; |
729 |
|
} |
730 |
|
|
731 |
< |
public final void forEachRemaining(Consumer<? super E> action) { |
731 |
> |
public void forEachRemaining(Consumer<? super E> action) { |
732 |
|
Objects.requireNonNull(action); |
733 |
< |
final Object[] elements = ArrayDeque.this.elements; |
734 |
< |
final int capacity = elements.length; |
735 |
< |
int k = remaining; |
736 |
< |
remaining = 0; |
737 |
< |
for (int i = cursor; --k >= 0; i = advance(i, capacity)) |
738 |
< |
action.accept(checkedElementAt(elements, i)); |
733 |
> |
final int k; |
734 |
> |
if ((k = remaining) > 0) { |
735 |
> |
remaining = 0; |
736 |
> |
ArrayDeque.forEachRemaining(action, elements, cursor, k); |
737 |
> |
if ((lastRet = cursor + k - 1) >= elements.length) |
738 |
> |
lastRet -= elements.length; |
739 |
> |
} |
740 |
|
} |
741 |
|
} |
742 |
|
|
743 |
|
private class DescendingIterator extends DeqIterator { |
744 |
|
DescendingIterator() { cursor = tail(); } |
745 |
|
|
746 |
< |
@Override int advance(int i, int modulus) { |
747 |
< |
return dec(i, modulus); |
746 |
> |
public final E next() { |
747 |
> |
if (remaining <= 0) |
748 |
> |
throw new NoSuchElementException(); |
749 |
> |
final Object[] es = elements; |
750 |
> |
E e = nonNullElementAt(es, cursor); |
751 |
> |
lastRet = cursor; |
752 |
> |
if (--cursor < 0) cursor = es.length - 1; |
753 |
> |
remaining--; |
754 |
> |
return e; |
755 |
> |
} |
756 |
> |
|
757 |
> |
void postDelete(boolean leftShifted) { |
758 |
> |
if (!leftShifted) |
759 |
> |
if (++cursor >= elements.length) cursor = 0; |
760 |
|
} |
761 |
|
|
762 |
< |
@Override void doRemove() { |
763 |
< |
if (!delete(lastRet)) |
764 |
< |
// if right-shifted, undo advance in next |
765 |
< |
cursor = inc(cursor, elements.length); |
762 |
> |
public final void forEachRemaining(Consumer<? super E> action) { |
763 |
> |
Objects.requireNonNull(action); |
764 |
> |
final int k; |
765 |
> |
if ((k = remaining) > 0) { |
766 |
> |
remaining = 0; |
767 |
> |
final Object[] es = elements; |
768 |
> |
int i, end, to, todo; |
769 |
> |
todo = (to = ((end = (i = cursor) - k) >= -1) ? end : -1) - end; |
770 |
> |
for (;; to = (i = es.length - 1) - todo, todo = 0) { |
771 |
> |
for (; i > to; i--) |
772 |
> |
action.accept(nonNullElementAt(es, i)); |
773 |
> |
if (todo == 0) break; |
774 |
> |
} |
775 |
> |
if ((lastRet = cursor - (k - 1)) < 0) |
776 |
> |
lastRet += es.length; |
777 |
> |
} |
778 |
|
} |
779 |
|
} |
780 |
|
|
832 |
|
|
833 |
|
public void forEachRemaining(Consumer<? super E> action) { |
834 |
|
Objects.requireNonNull(action); |
835 |
< |
final Object[] elements = ArrayDeque.this.elements; |
803 |
< |
final int capacity = elements.length; |
804 |
< |
int k = remaining(); |
835 |
> |
final int k = remaining(); // side effect! |
836 |
|
remaining = 0; |
837 |
< |
for (int i = cursor; --k >= 0; i = inc(i, capacity)) |
807 |
< |
action.accept(checkedElementAt(elements, i)); |
837 |
> |
ArrayDeque.forEachRemaining(action, elements, cursor, k); |
838 |
|
} |
839 |
|
|
840 |
|
public boolean tryAdvance(Consumer<? super E> action) { |
841 |
|
Objects.requireNonNull(action); |
842 |
< |
if (remaining() == 0) |
842 |
> |
final int k; |
843 |
> |
if ((k = remaining()) <= 0) |
844 |
|
return false; |
845 |
< |
action.accept(checkedElementAt(elements, cursor)); |
846 |
< |
cursor = inc(cursor, elements.length); |
847 |
< |
remaining--; |
845 |
> |
action.accept(nonNullElementAt(elements, cursor)); |
846 |
> |
if (++cursor >= elements.length) cursor = 0; |
847 |
> |
remaining = k - 1; |
848 |
|
return true; |
849 |
|
} |
850 |
|
|
860 |
|
} |
861 |
|
} |
862 |
|
|
863 |
< |
@Override |
863 |
> |
@SuppressWarnings("unchecked") |
864 |
|
public void forEach(Consumer<? super E> action) { |
834 |
– |
// checkInvariants(); |
865 |
|
Objects.requireNonNull(action); |
866 |
< |
final Object[] elements = this.elements; |
867 |
< |
final int capacity = elements.length; |
868 |
< |
for (int k = size, i = head; --k >= 0; i = inc(i, capacity)) |
869 |
< |
action.accept(elementAt(i)); |
866 |
> |
final Object[] es = elements; |
867 |
> |
int i, end, to, todo; |
868 |
> |
todo = (end = (i = head) + size) |
869 |
> |
- (to = (es.length - end >= 0) ? end : es.length); |
870 |
> |
for (;; to = todo, todo = 0, i = 0) { |
871 |
> |
for (; i < to; i++) |
872 |
> |
action.accept((E) es[i]); |
873 |
> |
if (todo == 0) break; |
874 |
> |
} |
875 |
|
// checkInvariants(); |
876 |
|
} |
877 |
|
|
878 |
|
/** |
879 |
+ |
* Calls action on remaining elements, starting at index i and |
880 |
+ |
* traversing in ascending order. A variant of forEach that also |
881 |
+ |
* checks for concurrent modification, for use in iterators. |
882 |
+ |
*/ |
883 |
+ |
static <E> void forEachRemaining( |
884 |
+ |
Consumer<? super E> action, Object[] es, int i, int remaining) { |
885 |
+ |
int end, to, todo; |
886 |
+ |
todo = (end = i + remaining) |
887 |
+ |
- (to = (es.length - end >= 0) ? end : es.length); |
888 |
+ |
for (;; to = todo, todo = 0, i = 0) { |
889 |
+ |
for (; i < to; i++) |
890 |
+ |
action.accept(nonNullElementAt(es, i)); |
891 |
+ |
if (todo == 0) break; |
892 |
+ |
} |
893 |
+ |
} |
894 |
+ |
|
895 |
+ |
/** |
896 |
|
* Replaces each element of this deque with the result of applying the |
897 |
|
* operator to that element, as specified by {@link List#replaceAll}. |
898 |
|
* |
899 |
|
* @param operator the operator to apply to each element |
900 |
< |
* @since 9 |
900 |
> |
* @since TBD |
901 |
|
*/ |
902 |
< |
public void replaceAll(UnaryOperator<E> operator) { |
902 |
> |
@SuppressWarnings("unchecked") |
903 |
> |
/* public */ void replaceAll(UnaryOperator<E> operator) { |
904 |
|
Objects.requireNonNull(operator); |
905 |
< |
final Object[] elements = this.elements; |
906 |
< |
final int capacity = elements.length; |
907 |
< |
for (int k = size, i = head; --k >= 0; i = inc(i, capacity)) |
908 |
< |
elements[i] = operator.apply(elementAt(i)); |
905 |
> |
final Object[] es = elements; |
906 |
> |
int i, end, to, todo; |
907 |
> |
todo = (end = (i = head) + size) |
908 |
> |
- (to = (es.length - end >= 0) ? end : es.length); |
909 |
> |
for (;; to = todo, todo = 0, i = 0) { |
910 |
> |
for (; i < to; i++) |
911 |
> |
es[i] = operator.apply((E) es[i]); |
912 |
> |
if (todo == 0) break; |
913 |
> |
} |
914 |
|
// checkInvariants(); |
915 |
|
} |
916 |
|
|
917 |
|
/** |
918 |
|
* @throws NullPointerException {@inheritDoc} |
919 |
|
*/ |
862 |
– |
@Override |
920 |
|
public boolean removeIf(Predicate<? super E> filter) { |
921 |
|
Objects.requireNonNull(filter); |
922 |
|
return bulkRemove(filter); |
925 |
|
/** |
926 |
|
* @throws NullPointerException {@inheritDoc} |
927 |
|
*/ |
871 |
– |
@Override |
928 |
|
public boolean removeAll(Collection<?> c) { |
929 |
|
Objects.requireNonNull(c); |
930 |
|
return bulkRemove(e -> c.contains(e)); |
933 |
|
/** |
934 |
|
* @throws NullPointerException {@inheritDoc} |
935 |
|
*/ |
880 |
– |
@Override |
936 |
|
public boolean retainAll(Collection<?> c) { |
937 |
|
Objects.requireNonNull(c); |
938 |
|
return bulkRemove(e -> !c.contains(e)); |
939 |
|
} |
940 |
|
|
941 |
|
/** Implementation of bulk remove methods. */ |
942 |
+ |
@SuppressWarnings("unchecked") |
943 |
|
private boolean bulkRemove(Predicate<? super E> filter) { |
944 |
|
// checkInvariants(); |
945 |
< |
final Object[] elements = this.elements; |
946 |
< |
final int capacity = elements.length; |
947 |
< |
int i = head, j = i, remaining = size, deleted = 0; |
945 |
> |
final Object[] es = elements; |
946 |
> |
int i, end, to, todo; |
947 |
> |
todo = (end = (i = head) + size) |
948 |
> |
- (to = (es.length - end >= 0) ? end : es.length); |
949 |
> |
// Optimize for initial run of non-removed elements |
950 |
> |
findFirstRemoved: |
951 |
> |
for (;; to = todo, todo = 0, i = 0) { |
952 |
> |
for (; i < to; i++) |
953 |
> |
if (filter.test((E) es[i])) |
954 |
> |
break findFirstRemoved; |
955 |
> |
if (todo == 0) return false; |
956 |
> |
} |
957 |
> |
bulkRemoveModified(filter, i, to, todo); |
958 |
> |
return true; |
959 |
> |
} |
960 |
> |
|
961 |
> |
/** |
962 |
> |
* Helper for bulkRemove, in case of at least one deletion. |
963 |
> |
* @param i valid index of first element to be deleted |
964 |
> |
*/ |
965 |
> |
@SuppressWarnings("unchecked") |
966 |
> |
private void bulkRemoveModified( |
967 |
> |
Predicate<? super E> filter, int i, int to, int todo) { |
968 |
> |
final Object[] es = elements; |
969 |
> |
final int capacity = es.length; |
970 |
> |
// a two-finger algorithm, with hare i and tortoise j |
971 |
> |
int j = i++; |
972 |
|
try { |
973 |
< |
for (; remaining > 0; remaining--, i = inc(i, capacity)) { |
974 |
< |
@SuppressWarnings("unchecked") E e = (E) elements[i]; |
975 |
< |
if (filter.test(e)) |
976 |
< |
deleted++; |
977 |
< |
else { |
978 |
< |
if (j != i) |
979 |
< |
elements[j] = e; |
980 |
< |
j = inc(j, capacity); |
981 |
< |
} |
973 |
> |
for (;;) { |
974 |
> |
E e; |
975 |
> |
// In this loop, i and j are on the same leg, with i > j |
976 |
> |
for (; i < to; i++) |
977 |
> |
if (!filter.test(e = (E) es[i])) |
978 |
> |
es[j++] = e; |
979 |
> |
if (todo == 0) break; |
980 |
> |
// In this loop, j is on the first leg, i on the second |
981 |
> |
for (to = todo, todo = 0, i = 0; i < to && j < capacity; i++) |
982 |
> |
if (!filter.test(e = (E) es[i])) |
983 |
> |
es[j++] = e; |
984 |
> |
if (i >= to) break; |
985 |
> |
j = 0; // j rejoins i on second leg |
986 |
|
} |
987 |
< |
return deleted > 0; |
987 |
> |
bulkRemoveClear(es, j, i); |
988 |
> |
// checkInvariants(); |
989 |
|
} catch (Throwable ex) { |
990 |
< |
for (; remaining > 0; |
991 |
< |
remaining--, i = inc(i, capacity), j = inc(j, capacity)) |
992 |
< |
elements[j] = elements[i]; |
993 |
< |
throw ex; |
994 |
< |
} finally { |
995 |
< |
size -= deleted; |
996 |
< |
for (; --deleted >= 0; j = inc(j, capacity)) |
912 |
< |
elements[j] = null; |
990 |
> |
// copy remaining elements |
991 |
> |
for (int remaining = (to - i) + todo; --remaining >= 0;) { |
992 |
> |
es[j] = es[i]; |
993 |
> |
if (++i >= capacity) i = 0; |
994 |
> |
if (++j >= capacity) j = 0; |
995 |
> |
} |
996 |
> |
bulkRemoveClear(es, j, i); |
997 |
|
// checkInvariants(); |
998 |
+ |
throw ex; |
999 |
|
} |
1000 |
|
} |
1001 |
|
|
1002 |
|
/** |
1003 |
+ |
* Nulls out all elements from index j upto index i. |
1004 |
+ |
*/ |
1005 |
+ |
private void bulkRemoveClear(Object[] es, int j, int i) { |
1006 |
+ |
int deleted; |
1007 |
+ |
if ((deleted = i - j) <= 0) deleted += es.length; |
1008 |
+ |
size -= deleted; |
1009 |
+ |
circularClear(es, j, deleted); |
1010 |
+ |
} |
1011 |
+ |
|
1012 |
+ |
/** |
1013 |
|
* Returns {@code true} if this deque contains the specified element. |
1014 |
|
* More formally, returns {@code true} if and only if this deque contains |
1015 |
|
* at least one element {@code e} such that {@code o.equals(e)}. |
1019 |
|
*/ |
1020 |
|
public boolean contains(Object o) { |
1021 |
|
if (o != null) { |
1022 |
< |
final Object[] elements = this.elements; |
1023 |
< |
final int capacity = elements.length; |
1024 |
< |
for (int k = size, i = head; --k >= 0; i = inc(i, capacity)) |
1025 |
< |
if (o.equals(elements[i])) |
1026 |
< |
return true; |
1022 |
> |
final Object[] es = elements; |
1023 |
> |
int i, end, to, todo; |
1024 |
> |
todo = (end = (i = head) + size) |
1025 |
> |
- (to = (es.length - end >= 0) ? end : es.length); |
1026 |
> |
for (;; to = todo, todo = 0, i = 0) { |
1027 |
> |
for (; i < to; i++) |
1028 |
> |
if (o.equals(es[i])) |
1029 |
> |
return true; |
1030 |
> |
if (todo == 0) break; |
1031 |
> |
} |
1032 |
|
} |
1033 |
|
return false; |
1034 |
|
} |
1055 |
|
* The deque will be empty after this call returns. |
1056 |
|
*/ |
1057 |
|
public void clear() { |
1058 |
< |
final Object[] elements = this.elements; |
959 |
< |
final int capacity = elements.length; |
960 |
< |
final int h = this.head; |
961 |
< |
final int s = size; |
962 |
< |
if (capacity - h >= s) |
963 |
< |
Arrays.fill(elements, h, h + s, null); |
964 |
< |
else { |
965 |
< |
Arrays.fill(elements, h, capacity, null); |
966 |
< |
Arrays.fill(elements, 0, s - capacity + h, null); |
967 |
< |
} |
1058 |
> |
circularClear(elements, head, size); |
1059 |
|
size = head = 0; |
1060 |
|
// checkInvariants(); |
1061 |
|
} |
1062 |
|
|
1063 |
|
/** |
1064 |
+ |
* Nulls out count elements, starting at array index from. |
1065 |
+ |
* Special case (from == es.length) is treated the same as (from == 0). |
1066 |
+ |
*/ |
1067 |
+ |
private static void circularClear(Object[] es, int from, int count) { |
1068 |
+ |
int end, to, todo; |
1069 |
+ |
todo = (end = from + count) |
1070 |
+ |
- (to = (es.length - end >= 0) ? end : es.length); |
1071 |
+ |
for (;; to = todo, todo = 0, from = 0) { |
1072 |
+ |
Arrays.fill(es, from, to, null); |
1073 |
+ |
if (todo == 0) break; |
1074 |
+ |
} |
1075 |
+ |
} |
1076 |
+ |
|
1077 |
+ |
/** |
1078 |
|
* Returns an array containing all of the elements in this deque |
1079 |
|
* in proper sequence (from first to last element). |
1080 |
|
* |
1088 |
|
* @return an array containing all of the elements in this deque |
1089 |
|
*/ |
1090 |
|
public Object[] toArray() { |
1091 |
< |
final int head = this.head; |
1092 |
< |
final int firstLeg; |
1093 |
< |
Object[] a = Arrays.copyOfRange(elements, head, head + size); |
1094 |
< |
if ((firstLeg = elements.length - head) < size) |
1095 |
< |
System.arraycopy(elements, 0, a, firstLeg, size - firstLeg); |
1091 |
> |
return toArray(Object[].class); |
1092 |
> |
} |
1093 |
> |
|
1094 |
> |
private <T> T[] toArray(Class<T[]> klazz) { |
1095 |
> |
final Object[] es = elements; |
1096 |
> |
final T[] a; |
1097 |
> |
final int head, len, end, todo; |
1098 |
> |
todo = size - (len = Math.min(size, es.length - (head = this.head))); |
1099 |
> |
if ((end = head + size) >= 0) { |
1100 |
> |
a = Arrays.copyOfRange(es, head, end, klazz); |
1101 |
> |
} else { |
1102 |
> |
// integer overflow! |
1103 |
> |
a = Arrays.copyOfRange(es, 0, size, klazz); |
1104 |
> |
System.arraycopy(es, head, a, 0, len); |
1105 |
> |
} |
1106 |
> |
if (todo > 0) |
1107 |
> |
System.arraycopy(es, 0, a, len, todo); |
1108 |
|
return a; |
1109 |
|
} |
1110 |
|
|
1146 |
|
*/ |
1147 |
|
@SuppressWarnings("unchecked") |
1148 |
|
public <T> T[] toArray(T[] a) { |
1149 |
< |
final Object[] elements = this.elements; |
1150 |
< |
final int head = this.head; |
1151 |
< |
final int firstLeg; |
1152 |
< |
boolean wrap = (firstLeg = elements.length - head) < size; |
1153 |
< |
if (size > a.length) { |
1154 |
< |
a = (T[]) Arrays.copyOfRange(elements, head, head + size, |
1155 |
< |
a.getClass()); |
1156 |
< |
} else { |
1157 |
< |
System.arraycopy(elements, head, a, 0, wrap ? firstLeg : size); |
1041 |
< |
if (size < a.length) |
1042 |
< |
a[size] = null; |
1149 |
> |
final int size; |
1150 |
> |
if ((size = this.size) > a.length) |
1151 |
> |
return toArray((Class<T[]>) a.getClass()); |
1152 |
> |
final Object[] es = elements; |
1153 |
> |
int i, j, len, todo; |
1154 |
> |
todo = size - (len = Math.min(size, es.length - (i = head))); |
1155 |
> |
for (j = 0;; j += len, len = todo, todo = 0, i = 0) { |
1156 |
> |
System.arraycopy(es, i, a, j, len); |
1157 |
> |
if (todo == 0) break; |
1158 |
|
} |
1159 |
< |
if (wrap) |
1160 |
< |
System.arraycopy(elements, 0, a, firstLeg, size - firstLeg); |
1159 |
> |
if (size < a.length) |
1160 |
> |
a[size] = null; |
1161 |
|
return a; |
1162 |
|
} |
1163 |
|
|
1198 |
|
s.writeInt(size); |
1199 |
|
|
1200 |
|
// Write out elements in order. |
1201 |
< |
final Object[] elements = this.elements; |
1202 |
< |
final int capacity = elements.length; |
1203 |
< |
for (int k = size, i = head; --k >= 0; i = inc(i, capacity)) |
1204 |
< |
s.writeObject(elements[i]); |
1201 |
> |
final Object[] es = elements; |
1202 |
> |
int i, end, to, todo; |
1203 |
> |
todo = (end = (i = head) + size) |
1204 |
> |
- (to = (es.length - end >= 0) ? end : es.length); |
1205 |
> |
for (;; to = todo, todo = 0, i = 0) { |
1206 |
> |
for (; i < to; i++) |
1207 |
> |
s.writeObject(es[i]); |
1208 |
> |
if (todo == 0) break; |
1209 |
> |
} |
1210 |
|
} |
1211 |
|
|
1212 |
|
/** |
1229 |
|
} |
1230 |
|
|
1231 |
|
/** debugging */ |
1232 |
< |
private void checkInvariants() { |
1232 |
> |
void checkInvariants() { |
1233 |
|
try { |
1234 |
|
int capacity = elements.length; |
1235 |
< |
assert size >= 0 && size <= capacity; |
1236 |
< |
assert head >= 0 && ((capacity == 0 && head == 0 && size == 0) |
1237 |
< |
|| head < capacity); |
1238 |
< |
assert size == 0 |
1239 |
< |
|| (elements[head] != null && elements[tail()] != null); |
1240 |
< |
assert size == capacity |
1241 |
< |
|| (elements[dec(head, capacity)] == null |
1122 |
< |
&& elements[inc(tail(), capacity)] == null); |
1235 |
> |
// assert size >= 0 && size <= capacity; |
1236 |
> |
// assert head >= 0; |
1237 |
> |
// assert capacity == 0 || head < capacity; |
1238 |
> |
// assert size == 0 || elements[head] != null; |
1239 |
> |
// assert size == 0 || elements[tail()] != null; |
1240 |
> |
// assert size == capacity || elements[dec(head, capacity)] == null; |
1241 |
> |
// assert size == capacity || elements[inc(tail(), capacity)] == null; |
1242 |
|
} catch (Throwable t) { |
1243 |
|
System.err.printf("head=%d size=%d capacity=%d%n", |
1244 |
|
head, size, elements.length); |