4 |
|
*/ |
5 |
|
|
6 |
|
package java.util; |
7 |
+ |
import java.io.Serializable; |
8 |
+ |
import java.util.function.Consumer; |
9 |
+ |
import java.util.stream.Stream; |
10 |
+ |
import java.util.stream.Streams; |
11 |
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|
12 |
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/** |
13 |
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* Resizable-array implementation of the {@link Deque} interface. Array |
18 |
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* {@link Stack} when used as a stack, and faster than {@link LinkedList} |
19 |
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* when used as a queue. |
20 |
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* |
21 |
< |
* <p>Most <tt>ArrayDeque</tt> operations run in amortized constant time. |
22 |
< |
* Exceptions include {@link #remove(Object) remove}, {@link |
23 |
< |
* #removeFirstOccurrence removeFirstOccurrence}, {@link #removeLastOccurrence |
24 |
< |
* removeLastOccurrence}, {@link #contains contains}, {@link #iterator |
25 |
< |
* iterator.remove()}, and the bulk operations, all of which run in linear |
26 |
< |
* time. |
21 |
> |
* <p>Most {@code ArrayDeque} operations run in amortized constant time. |
22 |
> |
* Exceptions include |
23 |
> |
* {@link #remove(Object) remove}, |
24 |
> |
* {@link #removeFirstOccurrence removeFirstOccurrence}, |
25 |
> |
* {@link #removeLastOccurrence removeLastOccurrence}, |
26 |
> |
* {@link #contains contains}, |
27 |
> |
* {@link #iterator iterator.remove()}, |
28 |
> |
* and the bulk operations, all of which run in linear time. |
29 |
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* |
30 |
< |
* <p>The iterators returned by this class's <tt>iterator</tt> method are |
31 |
< |
* <i>fail-fast</i>: If the deque is modified at any time after the iterator |
32 |
< |
* is created, in any way except through the iterator's own <tt>remove</tt> |
33 |
< |
* method, the iterator will generally throw a {@link |
30 |
> |
* <p>The iterators returned by this class's {@link #iterator() iterator} |
31 |
> |
* method are <em>fail-fast</em>: If the deque is modified at any time after |
32 |
> |
* the iterator is created, in any way except through the iterator's own |
33 |
> |
* {@code remove} method, the iterator will generally throw a {@link |
34 |
|
* ConcurrentModificationException}. Thus, in the face of concurrent |
35 |
|
* modification, the iterator fails quickly and cleanly, rather than risking |
36 |
|
* arbitrary, non-deterministic behavior at an undetermined time in the |
39 |
|
* <p>Note that the fail-fast behavior of an iterator cannot be guaranteed |
40 |
|
* as it is, generally speaking, impossible to make any hard guarantees in the |
41 |
|
* presence of unsynchronized concurrent modification. Fail-fast iterators |
42 |
< |
* throw <tt>ConcurrentModificationException</tt> on a best-effort basis. |
42 |
> |
* throw {@code ConcurrentModificationException} on a best-effort basis. |
43 |
|
* Therefore, it would be wrong to write a program that depended on this |
44 |
|
* exception for its correctness: <i>the fail-fast behavior of iterators |
45 |
|
* should be used only to detect bugs.</i> |
57 |
|
* @param <E> the type of elements held in this collection |
58 |
|
*/ |
59 |
|
public class ArrayDeque<E> extends AbstractCollection<E> |
60 |
< |
implements Deque<E>, Cloneable, java.io.Serializable |
60 |
> |
implements Deque<E>, Cloneable, Serializable |
61 |
|
{ |
62 |
|
/** |
63 |
|
* The array in which the elements of the deque are stored. |
69 |
|
* other. We also guarantee that all array cells not holding |
70 |
|
* deque elements are always null. |
71 |
|
*/ |
72 |
< |
private transient Object[] elements; |
72 |
> |
transient Object[] elements; // non-private to simplify nested class access |
73 |
|
|
74 |
|
/** |
75 |
|
* The index of the element at the head of the deque (which is the |
76 |
|
* element that would be removed by remove() or pop()); or an |
77 |
|
* arbitrary number equal to tail if the deque is empty. |
78 |
|
*/ |
79 |
< |
private transient int head; |
79 |
> |
transient int head; |
80 |
|
|
81 |
|
/** |
82 |
|
* The index at which the next element would be added to the tail |
83 |
|
* of the deque (via addLast(E), add(E), or push(E)). |
84 |
|
*/ |
85 |
< |
private transient int tail; |
85 |
> |
transient int tail; |
86 |
|
|
87 |
|
/** |
88 |
|
* The minimum capacity that we'll use for a newly created deque. |
93 |
|
// ****** Array allocation and resizing utilities ****** |
94 |
|
|
95 |
|
/** |
96 |
< |
* Allocate empty array to hold the given number of elements. |
96 |
> |
* Allocates empty array to hold the given number of elements. |
97 |
|
* |
98 |
|
* @param numElements the number of elements to hold |
99 |
|
*/ |
117 |
|
} |
118 |
|
|
119 |
|
/** |
120 |
< |
* Double the capacity of this deque. Call only when full, i.e., |
120 |
> |
* Doubles the capacity of this deque. Call only when full, i.e., |
121 |
|
* when head and tail have wrapped around to become equal. |
122 |
|
*/ |
123 |
|
private void doubleCapacity() { |
137 |
|
} |
138 |
|
|
139 |
|
/** |
134 |
– |
* Copies the elements from our element array into the specified array, |
135 |
– |
* in order (from first to last element in the deque). It is assumed |
136 |
– |
* that the array is large enough to hold all elements in the deque. |
137 |
– |
* |
138 |
– |
* @return its argument |
139 |
– |
*/ |
140 |
– |
private <T> T[] copyElements(T[] a) { |
141 |
– |
if (head < tail) { |
142 |
– |
System.arraycopy(elements, head, a, 0, size()); |
143 |
– |
} else if (head > tail) { |
144 |
– |
int headPortionLen = elements.length - head; |
145 |
– |
System.arraycopy(elements, head, a, 0, headPortionLen); |
146 |
– |
System.arraycopy(elements, 0, a, headPortionLen, tail); |
147 |
– |
} |
148 |
– |
return a; |
149 |
– |
} |
150 |
– |
|
151 |
– |
/** |
140 |
|
* Constructs an empty array deque with an initial capacity |
141 |
|
* sufficient to hold 16 elements. |
142 |
|
*/ |
207 |
|
* Inserts the specified element at the front of this deque. |
208 |
|
* |
209 |
|
* @param e the element to add |
210 |
< |
* @return <tt>true</tt> (as specified by {@link Deque#offerFirst}) |
210 |
> |
* @return {@code true} (as specified by {@link Deque#offerFirst}) |
211 |
|
* @throws NullPointerException if the specified element is null |
212 |
|
*/ |
213 |
|
public boolean offerFirst(E e) { |
219 |
|
* Inserts the specified element at the end of this deque. |
220 |
|
* |
221 |
|
* @param e the element to add |
222 |
< |
* @return <tt>true</tt> (as specified by {@link Deque#offerLast}) |
222 |
> |
* @return {@code true} (as specified by {@link Deque#offerLast}) |
223 |
|
* @throws NullPointerException if the specified element is null |
224 |
|
*/ |
225 |
|
public boolean offerLast(E e) { |
249 |
|
|
250 |
|
public E pollFirst() { |
251 |
|
int h = head; |
252 |
< |
@SuppressWarnings("unchecked") E result = (E) elements[h]; |
252 |
> |
@SuppressWarnings("unchecked") |
253 |
> |
E result = (E) elements[h]; |
254 |
|
// Element is null if deque empty |
255 |
|
if (result == null) |
256 |
|
return null; |
261 |
|
|
262 |
|
public E pollLast() { |
263 |
|
int t = (tail - 1) & (elements.length - 1); |
264 |
< |
@SuppressWarnings("unchecked") E result = (E) elements[t]; |
264 |
> |
@SuppressWarnings("unchecked") |
265 |
> |
E result = (E) elements[t]; |
266 |
|
if (result == null) |
267 |
|
return null; |
268 |
|
elements[t] = null; |
274 |
|
* @throws NoSuchElementException {@inheritDoc} |
275 |
|
*/ |
276 |
|
public E getFirst() { |
277 |
< |
@SuppressWarnings("unchecked") E result = (E) elements[head]; |
277 |
> |
@SuppressWarnings("unchecked") |
278 |
> |
E result = (E) elements[head]; |
279 |
|
if (result == null) |
280 |
|
throw new NoSuchElementException(); |
281 |
|
return result; |
307 |
|
* Removes the first occurrence of the specified element in this |
308 |
|
* deque (when traversing the deque from head to tail). |
309 |
|
* If the deque does not contain the element, it is unchanged. |
310 |
< |
* More formally, removes the first element <tt>e</tt> such that |
311 |
< |
* <tt>o.equals(e)</tt> (if such an element exists). |
312 |
< |
* Returns <tt>true</tt> if this deque contained the specified element |
310 |
> |
* More formally, removes the first element {@code e} such that |
311 |
> |
* {@code o.equals(e)} (if such an element exists). |
312 |
> |
* Returns {@code true} if this deque contained the specified element |
313 |
|
* (or equivalently, if this deque changed as a result of the call). |
314 |
|
* |
315 |
|
* @param o element to be removed from this deque, if present |
316 |
< |
* @return <tt>true</tt> if the deque contained the specified element |
316 |
> |
* @return {@code true} if the deque contained the specified element |
317 |
|
*/ |
318 |
|
public boolean removeFirstOccurrence(Object o) { |
319 |
|
if (o == null) |
335 |
|
* Removes the last occurrence of the specified element in this |
336 |
|
* deque (when traversing the deque from head to tail). |
337 |
|
* If the deque does not contain the element, it is unchanged. |
338 |
< |
* More formally, removes the last element <tt>e</tt> such that |
339 |
< |
* <tt>o.equals(e)</tt> (if such an element exists). |
340 |
< |
* Returns <tt>true</tt> if this deque contained the specified element |
338 |
> |
* More formally, removes the last element {@code e} such that |
339 |
> |
* {@code o.equals(e)} (if such an element exists). |
340 |
> |
* Returns {@code true} if this deque contained the specified element |
341 |
|
* (or equivalently, if this deque changed as a result of the call). |
342 |
|
* |
343 |
|
* @param o element to be removed from this deque, if present |
344 |
< |
* @return <tt>true</tt> if the deque contained the specified element |
344 |
> |
* @return {@code true} if the deque contained the specified element |
345 |
|
*/ |
346 |
|
public boolean removeLastOccurrence(Object o) { |
347 |
|
if (o == null) |
367 |
|
* <p>This method is equivalent to {@link #addLast}. |
368 |
|
* |
369 |
|
* @param e the element to add |
370 |
< |
* @return <tt>true</tt> (as specified by {@link Collection#add}) |
370 |
> |
* @return {@code true} (as specified by {@link Collection#add}) |
371 |
|
* @throws NullPointerException if the specified element is null |
372 |
|
*/ |
373 |
|
public boolean add(E e) { |
381 |
|
* <p>This method is equivalent to {@link #offerLast}. |
382 |
|
* |
383 |
|
* @param e the element to add |
384 |
< |
* @return <tt>true</tt> (as specified by {@link Queue#offer}) |
384 |
> |
* @return {@code true} (as specified by {@link Queue#offer}) |
385 |
|
* @throws NullPointerException if the specified element is null |
386 |
|
*/ |
387 |
|
public boolean offer(E e) { |
406 |
|
/** |
407 |
|
* Retrieves and removes the head of the queue represented by this deque |
408 |
|
* (in other words, the first element of this deque), or returns |
409 |
< |
* <tt>null</tt> if this deque is empty. |
409 |
> |
* {@code null} if this deque is empty. |
410 |
|
* |
411 |
|
* <p>This method is equivalent to {@link #pollFirst}. |
412 |
|
* |
413 |
|
* @return the head of the queue represented by this deque, or |
414 |
< |
* <tt>null</tt> if this deque is empty |
414 |
> |
* {@code null} if this deque is empty |
415 |
|
*/ |
416 |
|
public E poll() { |
417 |
|
return pollFirst(); |
433 |
|
|
434 |
|
/** |
435 |
|
* Retrieves, but does not remove, the head of the queue represented by |
436 |
< |
* this deque, or returns <tt>null</tt> if this deque is empty. |
436 |
> |
* this deque, or returns {@code null} if this deque is empty. |
437 |
|
* |
438 |
|
* <p>This method is equivalent to {@link #peekFirst}. |
439 |
|
* |
440 |
|
* @return the head of the queue represented by this deque, or |
441 |
< |
* <tt>null</tt> if this deque is empty |
441 |
> |
* {@code null} if this deque is empty |
442 |
|
*/ |
443 |
|
public E peek() { |
444 |
|
return peekFirst(); |
542 |
|
} |
543 |
|
|
544 |
|
/** |
545 |
< |
* Returns <tt>true</tt> if this deque contains no elements. |
545 |
> |
* Returns {@code true} if this deque contains no elements. |
546 |
|
* |
547 |
< |
* @return <tt>true</tt> if this deque contains no elements |
547 |
> |
* @return {@code true} if this deque contains no elements |
548 |
|
*/ |
549 |
|
public boolean isEmpty() { |
550 |
|
return head == tail; |
591 |
|
public E next() { |
592 |
|
if (cursor == fence) |
593 |
|
throw new NoSuchElementException(); |
594 |
< |
@SuppressWarnings("unchecked") E result = (E) elements[cursor]; |
594 |
> |
@SuppressWarnings("unchecked") |
595 |
> |
E result = (E) elements[cursor]; |
596 |
|
// This check doesn't catch all possible comodifications, |
597 |
|
// but does catch the ones that corrupt traversal |
598 |
|
if (tail != fence || result == null) |
613 |
|
} |
614 |
|
} |
615 |
|
|
616 |
+ |
/** |
617 |
+ |
* This class is nearly a mirror-image of DeqIterator, using tail |
618 |
+ |
* instead of head for initial cursor, and head instead of tail |
619 |
+ |
* for fence. |
620 |
+ |
*/ |
621 |
|
private class DescendingIterator implements Iterator<E> { |
625 |
– |
/* |
626 |
– |
* This class is nearly a mirror-image of DeqIterator, using |
627 |
– |
* tail instead of head for initial cursor, and head instead of |
628 |
– |
* tail for fence. |
629 |
– |
*/ |
622 |
|
private int cursor = tail; |
623 |
|
private int fence = head; |
624 |
|
private int lastRet = -1; |
631 |
|
if (cursor == fence) |
632 |
|
throw new NoSuchElementException(); |
633 |
|
cursor = (cursor - 1) & (elements.length - 1); |
634 |
< |
@SuppressWarnings("unchecked") E result = (E) elements[cursor]; |
634 |
> |
@SuppressWarnings("unchecked") |
635 |
> |
E result = (E) elements[cursor]; |
636 |
|
if (head != fence || result == null) |
637 |
|
throw new ConcurrentModificationException(); |
638 |
|
lastRet = cursor; |
651 |
|
} |
652 |
|
|
653 |
|
/** |
654 |
< |
* Returns <tt>true</tt> if this deque contains the specified element. |
655 |
< |
* More formally, returns <tt>true</tt> if and only if this deque contains |
656 |
< |
* at least one element <tt>e</tt> such that <tt>o.equals(e)</tt>. |
654 |
> |
* Returns {@code true} if this deque contains the specified element. |
655 |
> |
* More formally, returns {@code true} if and only if this deque contains |
656 |
> |
* at least one element {@code e} such that {@code o.equals(e)}. |
657 |
|
* |
658 |
|
* @param o object to be checked for containment in this deque |
659 |
< |
* @return <tt>true</tt> if this deque contains the specified element |
659 |
> |
* @return {@code true} if this deque contains the specified element |
660 |
|
*/ |
661 |
|
public boolean contains(Object o) { |
662 |
|
if (o == null) |
675 |
|
/** |
676 |
|
* Removes a single instance of the specified element from this deque. |
677 |
|
* If the deque does not contain the element, it is unchanged. |
678 |
< |
* More formally, removes the first element <tt>e</tt> such that |
679 |
< |
* <tt>o.equals(e)</tt> (if such an element exists). |
680 |
< |
* Returns <tt>true</tt> if this deque contained the specified element |
678 |
> |
* More formally, removes the first element {@code e} such that |
679 |
> |
* {@code o.equals(e)} (if such an element exists). |
680 |
> |
* Returns {@code true} if this deque contained the specified element |
681 |
|
* (or equivalently, if this deque changed as a result of the call). |
682 |
|
* |
683 |
< |
* <p>This method is equivalent to {@link #removeFirstOccurrence}. |
683 |
> |
* <p>This method is equivalent to {@link #removeFirstOccurrence(Object)}. |
684 |
|
* |
685 |
|
* @param o element to be removed from this deque, if present |
686 |
< |
* @return <tt>true</tt> if this deque contained the specified element |
686 |
> |
* @return {@code true} if this deque contained the specified element |
687 |
|
*/ |
688 |
|
public boolean remove(Object o) { |
689 |
|
return removeFirstOccurrence(o); |
721 |
|
* @return an array containing all of the elements in this deque |
722 |
|
*/ |
723 |
|
public Object[] toArray() { |
724 |
< |
return copyElements(new Object[size()]); |
724 |
> |
final int head = this.head; |
725 |
> |
final int tail = this.tail; |
726 |
> |
boolean wrap = (tail < head); |
727 |
> |
int end = wrap ? tail + elements.length : tail; |
728 |
> |
Object[] a = Arrays.copyOfRange(elements, head, end); |
729 |
> |
if (wrap) |
730 |
> |
System.arraycopy(elements, 0, a, elements.length - head, tail); |
731 |
> |
return a; |
732 |
|
} |
733 |
|
|
734 |
|
/** |
742 |
|
* <p>If this deque fits in the specified array with room to spare |
743 |
|
* (i.e., the array has more elements than this deque), the element in |
744 |
|
* the array immediately following the end of the deque is set to |
745 |
< |
* <tt>null</tt>. |
745 |
> |
* {@code null}. |
746 |
|
* |
747 |
|
* <p>Like the {@link #toArray()} method, this method acts as bridge between |
748 |
|
* array-based and collection-based APIs. Further, this method allows |
749 |
|
* precise control over the runtime type of the output array, and may, |
750 |
|
* under certain circumstances, be used to save allocation costs. |
751 |
|
* |
752 |
< |
* <p>Suppose <tt>x</tt> is a deque known to contain only strings. |
752 |
> |
* <p>Suppose {@code x} is a deque known to contain only strings. |
753 |
|
* The following code can be used to dump the deque into a newly |
754 |
< |
* allocated array of <tt>String</tt>: |
754 |
> |
* allocated array of {@code String}: |
755 |
|
* |
756 |
|
* <pre> {@code String[] y = x.toArray(new String[0]);}</pre> |
757 |
|
* |
758 |
< |
* Note that <tt>toArray(new Object[0])</tt> is identical in function to |
759 |
< |
* <tt>toArray()</tt>. |
758 |
> |
* Note that {@code toArray(new Object[0])} is identical in function to |
759 |
> |
* {@code toArray()}. |
760 |
|
* |
761 |
|
* @param a the array into which the elements of the deque are to |
762 |
|
* be stored, if it is big enough; otherwise, a new array of the |
769 |
|
*/ |
770 |
|
@SuppressWarnings("unchecked") |
771 |
|
public <T> T[] toArray(T[] a) { |
772 |
< |
int size = size(); |
773 |
< |
if (a.length < size) |
774 |
< |
a = (T[])java.lang.reflect.Array.newInstance( |
775 |
< |
a.getClass().getComponentType(), size); |
776 |
< |
copyElements(a); |
777 |
< |
if (a.length > size) |
778 |
< |
a[size] = null; |
772 |
> |
final int head = this.head; |
773 |
> |
final int tail = this.tail; |
774 |
> |
boolean wrap = (tail < head); |
775 |
> |
int size = (tail - head) + (wrap ? elements.length : 0); |
776 |
> |
int firstLeg = size - (wrap ? tail : 0); |
777 |
> |
int len = a.length; |
778 |
> |
if (size > len) { |
779 |
> |
a = (T[]) Arrays.copyOfRange(elements, head, head + size, |
780 |
> |
a.getClass()); |
781 |
> |
} else { |
782 |
> |
System.arraycopy(elements, head, a, 0, firstLeg); |
783 |
> |
if (size < len) |
784 |
> |
a[size] = null; |
785 |
> |
} |
786 |
> |
if (wrap) |
787 |
> |
System.arraycopy(elements, 0, a, firstLeg, tail); |
788 |
|
return a; |
789 |
|
} |
790 |
|
|
801 |
|
ArrayDeque<E> result = (ArrayDeque<E>) super.clone(); |
802 |
|
result.elements = Arrays.copyOf(elements, elements.length); |
803 |
|
return result; |
795 |
– |
|
804 |
|
} catch (CloneNotSupportedException e) { |
805 |
|
throw new AssertionError(); |
806 |
|
} |
807 |
|
} |
808 |
|
|
801 |
– |
/** |
802 |
– |
* Appease the serialization gods. |
803 |
– |
*/ |
809 |
|
private static final long serialVersionUID = 2340985798034038923L; |
810 |
|
|
811 |
|
/** |
812 |
< |
* Serialize this deque. |
812 |
> |
* Saves this deque to a stream (that is, serializes it). |
813 |
|
* |
814 |
< |
* @serialData The current size (<tt>int</tt>) of the deque, |
814 |
> |
* @serialData The current size ({@code int}) of the deque, |
815 |
|
* followed by all of its elements (each an object reference) in |
816 |
|
* first-to-last order. |
817 |
|
*/ |
829 |
|
} |
830 |
|
|
831 |
|
/** |
832 |
< |
* Deserialize this deque. |
832 |
> |
* Reconstitutes this deque from a stream (that is, deserializes it). |
833 |
|
*/ |
834 |
|
private void readObject(java.io.ObjectInputStream s) |
835 |
|
throws java.io.IOException, ClassNotFoundException { |
845 |
|
for (int i = 0; i < size; i++) |
846 |
|
elements[i] = s.readObject(); |
847 |
|
} |
848 |
+ |
|
849 |
+ |
public Spliterator<E> spliterator() { |
850 |
+ |
return new DeqSpliterator<E>(this, -1, -1); |
851 |
+ |
} |
852 |
+ |
|
853 |
+ |
static final class DeqSpliterator<E> implements Spliterator<E> { |
854 |
+ |
private final ArrayDeque<E> deq; |
855 |
+ |
private int fence; // -1 until first use |
856 |
+ |
private int index; // current index, modified on traverse/split |
857 |
+ |
|
858 |
+ |
/** Creates new spliterator covering the given array and range */ |
859 |
+ |
DeqSpliterator(ArrayDeque<E> deq, int origin, int fence) { |
860 |
+ |
this.deq = deq; |
861 |
+ |
this.index = origin; |
862 |
+ |
this.fence = fence; |
863 |
+ |
} |
864 |
+ |
|
865 |
+ |
private int getFence() { // force initialization |
866 |
+ |
int t; |
867 |
+ |
if ((t = fence) < 0) { |
868 |
+ |
t = fence = deq.tail; |
869 |
+ |
index = deq.head; |
870 |
+ |
} |
871 |
+ |
return t; |
872 |
+ |
} |
873 |
+ |
|
874 |
+ |
public Spliterator<E> trySplit() { |
875 |
+ |
int t = getFence(), h = index, n = deq.elements.length; |
876 |
+ |
if (h != t && ((h + 1) & (n - 1)) != t) { |
877 |
+ |
if (h > t) |
878 |
+ |
t += n; |
879 |
+ |
int m = ((h + t) >>> 1) & (n - 1); |
880 |
+ |
return new DeqSpliterator<>(deq, h, index = m); |
881 |
+ |
} |
882 |
+ |
return null; |
883 |
+ |
} |
884 |
+ |
|
885 |
+ |
public void forEachRemaining(Consumer<? super E> consumer) { |
886 |
+ |
if (consumer == null) |
887 |
+ |
throw new NullPointerException(); |
888 |
+ |
Object[] a = deq.elements; |
889 |
+ |
int m = a.length - 1, f = getFence(), i = index; |
890 |
+ |
index = f; |
891 |
+ |
while (i != f) { |
892 |
+ |
@SuppressWarnings("unchecked") E e = (E)a[i]; |
893 |
+ |
i = (i + 1) & m; |
894 |
+ |
if (e == null) |
895 |
+ |
throw new ConcurrentModificationException(); |
896 |
+ |
consumer.accept(e); |
897 |
+ |
} |
898 |
+ |
} |
899 |
+ |
|
900 |
+ |
public boolean tryAdvance(Consumer<? super E> consumer) { |
901 |
+ |
if (consumer == null) |
902 |
+ |
throw new NullPointerException(); |
903 |
+ |
Object[] a = deq.elements; |
904 |
+ |
int m = a.length - 1, f = getFence(), i = index; |
905 |
+ |
if (i != fence) { |
906 |
+ |
@SuppressWarnings("unchecked") E e = (E)a[i]; |
907 |
+ |
index = (i + 1) & m; |
908 |
+ |
if (e == null) |
909 |
+ |
throw new ConcurrentModificationException(); |
910 |
+ |
consumer.accept(e); |
911 |
+ |
return true; |
912 |
+ |
} |
913 |
+ |
return false; |
914 |
+ |
} |
915 |
+ |
|
916 |
+ |
public long estimateSize() { |
917 |
+ |
int n = getFence() - index; |
918 |
+ |
if (n < 0) |
919 |
+ |
n += deq.elements.length; |
920 |
+ |
return (long) n; |
921 |
+ |
} |
922 |
+ |
|
923 |
+ |
@Override |
924 |
+ |
public int characteristics() { |
925 |
+ |
return Spliterator.ORDERED | Spliterator.SIZED | |
926 |
+ |
Spliterator.NONNULL | Spliterator.SUBSIZED; |
927 |
+ |
} |
928 |
+ |
} |
929 |
+ |
|
930 |
|
} |