1 |
/* |
2 |
* Written by Doug Lea with assistance from members of JCP JSR-166 |
3 |
* Expert Group. Adapted and released, under explicit permission, |
4 |
* from JDK ArrayList.java which carries the following copyright: |
5 |
* |
6 |
* Copyright 1997 by Sun Microsystems, Inc., |
7 |
* 901 San Antonio Road, Palo Alto, California, 94303, U.S.A. |
8 |
* All rights reserved. |
9 |
* |
10 |
* This software is the confidential and proprietary information |
11 |
* of Sun Microsystems, Inc. ("Confidential Information"). You |
12 |
* shall not disclose such Confidential Information and shall use |
13 |
* it only in accordance with the terms of the license agreement |
14 |
* you entered into with Sun. |
15 |
*/ |
16 |
|
17 |
package java.util.concurrent; |
18 |
|
19 |
import java.lang.reflect.Field; |
20 |
import java.util.AbstractList; |
21 |
import java.util.Arrays; |
22 |
import java.util.Collection; |
23 |
import java.util.Comparator; |
24 |
import java.util.ConcurrentModificationException; |
25 |
import java.util.Iterator; |
26 |
import java.util.List; |
27 |
import java.util.ListIterator; |
28 |
import java.util.NoSuchElementException; |
29 |
import java.util.Objects; |
30 |
import java.util.RandomAccess; |
31 |
import java.util.Spliterator; |
32 |
import java.util.Spliterators; |
33 |
import java.util.function.Consumer; |
34 |
import java.util.function.Predicate; |
35 |
import java.util.function.UnaryOperator; |
36 |
|
37 |
/** |
38 |
* A thread-safe variant of {@link java.util.ArrayList} in which all mutative |
39 |
* operations ({@code add}, {@code set}, and so on) are implemented by |
40 |
* making a fresh copy of the underlying array. |
41 |
* |
42 |
* <p>This is ordinarily too costly, but may be <em>more</em> efficient |
43 |
* than alternatives when traversal operations vastly outnumber |
44 |
* mutations, and is useful when you cannot or don't want to |
45 |
* synchronize traversals, yet need to preclude interference among |
46 |
* concurrent threads. The "snapshot" style iterator method uses a |
47 |
* reference to the state of the array at the point that the iterator |
48 |
* was created. This array never changes during the lifetime of the |
49 |
* iterator, so interference is impossible and the iterator is |
50 |
* guaranteed not to throw {@code ConcurrentModificationException}. |
51 |
* The iterator will not reflect additions, removals, or changes to |
52 |
* the list since the iterator was created. Element-changing |
53 |
* operations on iterators themselves ({@code remove}, {@code set}, and |
54 |
* {@code add}) are not supported. These methods throw |
55 |
* {@code UnsupportedOperationException}. |
56 |
* |
57 |
* <p>All elements are permitted, including {@code null}. |
58 |
* |
59 |
* <p>Memory consistency effects: As with other concurrent |
60 |
* collections, actions in a thread prior to placing an object into a |
61 |
* {@code CopyOnWriteArrayList} |
62 |
* <a href="package-summary.html#MemoryVisibility"><i>happen-before</i></a> |
63 |
* actions subsequent to the access or removal of that element from |
64 |
* the {@code CopyOnWriteArrayList} in another thread. |
65 |
* |
66 |
* <p>This class is a member of the |
67 |
* <a href="{@docRoot}/../technotes/guides/collections/index.html"> |
68 |
* Java Collections Framework</a>. |
69 |
* |
70 |
* @since 1.5 |
71 |
* @author Doug Lea |
72 |
* @param <E> the type of elements held in this list |
73 |
*/ |
74 |
public class CopyOnWriteArrayList<E> |
75 |
implements List<E>, RandomAccess, Cloneable, java.io.Serializable { |
76 |
private static final long serialVersionUID = 8673264195747942595L; |
77 |
|
78 |
/** |
79 |
* The lock protecting all mutators. (We have a mild preference |
80 |
* for builtin monitors over ReentrantLock when either will do.) |
81 |
*/ |
82 |
final transient Object lock = new Object(); |
83 |
|
84 |
/** The array, accessed only via getArray/setArray. */ |
85 |
private transient volatile Object[] array; |
86 |
|
87 |
/** |
88 |
* Gets the array. Non-private so as to also be accessible |
89 |
* from CopyOnWriteArraySet class. |
90 |
*/ |
91 |
final Object[] getArray() { |
92 |
return array; |
93 |
} |
94 |
|
95 |
/** |
96 |
* Sets the array. |
97 |
*/ |
98 |
final void setArray(Object[] a) { |
99 |
array = a; |
100 |
} |
101 |
|
102 |
/** |
103 |
* Creates an empty list. |
104 |
*/ |
105 |
public CopyOnWriteArrayList() { |
106 |
setArray(new Object[0]); |
107 |
} |
108 |
|
109 |
/** |
110 |
* Creates a list containing the elements of the specified |
111 |
* collection, in the order they are returned by the collection's |
112 |
* iterator. |
113 |
* |
114 |
* @param c the collection of initially held elements |
115 |
* @throws NullPointerException if the specified collection is null |
116 |
*/ |
117 |
public CopyOnWriteArrayList(Collection<? extends E> c) { |
118 |
Object[] elements; |
119 |
if (c.getClass() == CopyOnWriteArrayList.class) |
120 |
elements = ((CopyOnWriteArrayList<?>)c).getArray(); |
121 |
else { |
122 |
elements = c.toArray(); |
123 |
// defend against c.toArray (incorrectly) not returning Object[] |
124 |
// (see e.g. https://bugs.openjdk.java.net/browse/JDK-6260652) |
125 |
if (elements.getClass() != Object[].class) |
126 |
elements = Arrays.copyOf(elements, elements.length, Object[].class); |
127 |
} |
128 |
setArray(elements); |
129 |
} |
130 |
|
131 |
/** |
132 |
* Creates a list holding a copy of the given array. |
133 |
* |
134 |
* @param toCopyIn the array (a copy of this array is used as the |
135 |
* internal array) |
136 |
* @throws NullPointerException if the specified array is null |
137 |
*/ |
138 |
public CopyOnWriteArrayList(E[] toCopyIn) { |
139 |
setArray(Arrays.copyOf(toCopyIn, toCopyIn.length, Object[].class)); |
140 |
} |
141 |
|
142 |
/** |
143 |
* Returns the number of elements in this list. |
144 |
* |
145 |
* @return the number of elements in this list |
146 |
*/ |
147 |
public int size() { |
148 |
return getArray().length; |
149 |
} |
150 |
|
151 |
/** |
152 |
* Returns {@code true} if this list contains no elements. |
153 |
* |
154 |
* @return {@code true} if this list contains no elements |
155 |
*/ |
156 |
public boolean isEmpty() { |
157 |
return size() == 0; |
158 |
} |
159 |
|
160 |
/** |
161 |
* static version of indexOf, to allow repeated calls without |
162 |
* needing to re-acquire array each time. |
163 |
* @param o element to search for |
164 |
* @param elements the array |
165 |
* @param index first index to search |
166 |
* @param fence one past last index to search |
167 |
* @return index of element, or -1 if absent |
168 |
*/ |
169 |
private static int indexOf(Object o, Object[] elements, |
170 |
int index, int fence) { |
171 |
if (o == null) { |
172 |
for (int i = index; i < fence; i++) |
173 |
if (elements[i] == null) |
174 |
return i; |
175 |
} else { |
176 |
for (int i = index; i < fence; i++) |
177 |
if (o.equals(elements[i])) |
178 |
return i; |
179 |
} |
180 |
return -1; |
181 |
} |
182 |
|
183 |
/** |
184 |
* static version of lastIndexOf. |
185 |
* @param o element to search for |
186 |
* @param elements the array |
187 |
* @param index first index to search |
188 |
* @return index of element, or -1 if absent |
189 |
*/ |
190 |
private static int lastIndexOf(Object o, Object[] elements, int index) { |
191 |
if (o == null) { |
192 |
for (int i = index; i >= 0; i--) |
193 |
if (elements[i] == null) |
194 |
return i; |
195 |
} else { |
196 |
for (int i = index; i >= 0; i--) |
197 |
if (o.equals(elements[i])) |
198 |
return i; |
199 |
} |
200 |
return -1; |
201 |
} |
202 |
|
203 |
/** |
204 |
* Returns {@code true} if this list contains the specified element. |
205 |
* More formally, returns {@code true} if and only if this list contains |
206 |
* at least one element {@code e} such that {@code Objects.equals(o, e)}. |
207 |
* |
208 |
* @param o element whose presence in this list is to be tested |
209 |
* @return {@code true} if this list contains the specified element |
210 |
*/ |
211 |
public boolean contains(Object o) { |
212 |
Object[] elements = getArray(); |
213 |
return indexOf(o, elements, 0, elements.length) >= 0; |
214 |
} |
215 |
|
216 |
/** |
217 |
* {@inheritDoc} |
218 |
*/ |
219 |
public int indexOf(Object o) { |
220 |
Object[] elements = getArray(); |
221 |
return indexOf(o, elements, 0, elements.length); |
222 |
} |
223 |
|
224 |
/** |
225 |
* Returns the index of the first occurrence of the specified element in |
226 |
* this list, searching forwards from {@code index}, or returns -1 if |
227 |
* the element is not found. |
228 |
* More formally, returns the lowest index {@code i} such that |
229 |
* {@code i >= index && Objects.equals(get(i), e)}, |
230 |
* or -1 if there is no such index. |
231 |
* |
232 |
* @param e element to search for |
233 |
* @param index index to start searching from |
234 |
* @return the index of the first occurrence of the element in |
235 |
* this list at position {@code index} or later in the list; |
236 |
* {@code -1} if the element is not found. |
237 |
* @throws IndexOutOfBoundsException if the specified index is negative |
238 |
*/ |
239 |
public int indexOf(E e, int index) { |
240 |
Object[] elements = getArray(); |
241 |
return indexOf(e, elements, index, elements.length); |
242 |
} |
243 |
|
244 |
/** |
245 |
* {@inheritDoc} |
246 |
*/ |
247 |
public int lastIndexOf(Object o) { |
248 |
Object[] elements = getArray(); |
249 |
return lastIndexOf(o, elements, elements.length - 1); |
250 |
} |
251 |
|
252 |
/** |
253 |
* Returns the index of the last occurrence of the specified element in |
254 |
* this list, searching backwards from {@code index}, or returns -1 if |
255 |
* the element is not found. |
256 |
* More formally, returns the highest index {@code i} such that |
257 |
* {@code i <= index && Objects.equals(get(i), e)}, |
258 |
* or -1 if there is no such index. |
259 |
* |
260 |
* @param e element to search for |
261 |
* @param index index to start searching backwards from |
262 |
* @return the index of the last occurrence of the element at position |
263 |
* less than or equal to {@code index} in this list; |
264 |
* -1 if the element is not found. |
265 |
* @throws IndexOutOfBoundsException if the specified index is greater |
266 |
* than or equal to the current size of this list |
267 |
*/ |
268 |
public int lastIndexOf(E e, int index) { |
269 |
Object[] elements = getArray(); |
270 |
return lastIndexOf(e, elements, index); |
271 |
} |
272 |
|
273 |
/** |
274 |
* Returns a shallow copy of this list. (The elements themselves |
275 |
* are not copied.) |
276 |
* |
277 |
* @return a clone of this list |
278 |
*/ |
279 |
public Object clone() { |
280 |
try { |
281 |
@SuppressWarnings("unchecked") |
282 |
CopyOnWriteArrayList<E> clone = |
283 |
(CopyOnWriteArrayList<E>) super.clone(); |
284 |
clone.resetLock(); |
285 |
return clone; |
286 |
} catch (CloneNotSupportedException e) { |
287 |
// this shouldn't happen, since we are Cloneable |
288 |
throw new InternalError(); |
289 |
} |
290 |
} |
291 |
|
292 |
/** |
293 |
* Returns an array containing all of the elements in this list |
294 |
* in proper sequence (from first to last element). |
295 |
* |
296 |
* <p>The returned array will be "safe" in that no references to it are |
297 |
* maintained by this list. (In other words, this method must allocate |
298 |
* a new array). The caller is thus free to modify the returned array. |
299 |
* |
300 |
* <p>This method acts as bridge between array-based and collection-based |
301 |
* APIs. |
302 |
* |
303 |
* @return an array containing all the elements in this list |
304 |
*/ |
305 |
public Object[] toArray() { |
306 |
Object[] elements = getArray(); |
307 |
return Arrays.copyOf(elements, elements.length); |
308 |
} |
309 |
|
310 |
/** |
311 |
* Returns an array containing all of the elements in this list in |
312 |
* proper sequence (from first to last element); the runtime type of |
313 |
* the returned array is that of the specified array. If the list fits |
314 |
* in the specified array, it is returned therein. Otherwise, a new |
315 |
* array is allocated with the runtime type of the specified array and |
316 |
* the size of this list. |
317 |
* |
318 |
* <p>If this list fits in the specified array with room to spare |
319 |
* (i.e., the array has more elements than this list), the element in |
320 |
* the array immediately following the end of the list is set to |
321 |
* {@code null}. (This is useful in determining the length of this |
322 |
* list <i>only</i> if the caller knows that this list does not contain |
323 |
* any null elements.) |
324 |
* |
325 |
* <p>Like the {@link #toArray()} method, this method acts as bridge between |
326 |
* array-based and collection-based APIs. Further, this method allows |
327 |
* precise control over the runtime type of the output array, and may, |
328 |
* under certain circumstances, be used to save allocation costs. |
329 |
* |
330 |
* <p>Suppose {@code x} is a list known to contain only strings. |
331 |
* The following code can be used to dump the list into a newly |
332 |
* allocated array of {@code String}: |
333 |
* |
334 |
* <pre> {@code String[] y = x.toArray(new String[0]);}</pre> |
335 |
* |
336 |
* Note that {@code toArray(new Object[0])} is identical in function to |
337 |
* {@code toArray()}. |
338 |
* |
339 |
* @param a the array into which the elements of the list are to |
340 |
* be stored, if it is big enough; otherwise, a new array of the |
341 |
* same runtime type is allocated for this purpose. |
342 |
* @return an array containing all the elements in this list |
343 |
* @throws ArrayStoreException if the runtime type of the specified array |
344 |
* is not a supertype of the runtime type of every element in |
345 |
* this list |
346 |
* @throws NullPointerException if the specified array is null |
347 |
*/ |
348 |
@SuppressWarnings("unchecked") |
349 |
public <T> T[] toArray(T[] a) { |
350 |
Object[] elements = getArray(); |
351 |
int len = elements.length; |
352 |
if (a.length < len) |
353 |
return (T[]) Arrays.copyOf(elements, len, a.getClass()); |
354 |
else { |
355 |
System.arraycopy(elements, 0, a, 0, len); |
356 |
if (a.length > len) |
357 |
a[len] = null; |
358 |
return a; |
359 |
} |
360 |
} |
361 |
|
362 |
// Positional Access Operations |
363 |
|
364 |
@SuppressWarnings("unchecked") |
365 |
static <E> E elementAt(Object[] a, int index) { |
366 |
return (E) a[index]; |
367 |
} |
368 |
|
369 |
static String outOfBounds(int index, int size) { |
370 |
return "Index: " + index + ", Size: " + size; |
371 |
} |
372 |
|
373 |
/** |
374 |
* {@inheritDoc} |
375 |
* |
376 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
377 |
*/ |
378 |
public E get(int index) { |
379 |
return elementAt(getArray(), index); |
380 |
} |
381 |
|
382 |
/** |
383 |
* Replaces the element at the specified position in this list with the |
384 |
* specified element. |
385 |
* |
386 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
387 |
*/ |
388 |
public E set(int index, E element) { |
389 |
synchronized (lock) { |
390 |
Object[] elements = getArray(); |
391 |
E oldValue = elementAt(elements, index); |
392 |
|
393 |
if (oldValue != element) { |
394 |
int len = elements.length; |
395 |
Object[] newElements = Arrays.copyOf(elements, len); |
396 |
newElements[index] = element; |
397 |
setArray(newElements); |
398 |
} else { |
399 |
// Not quite a no-op; ensures volatile write semantics |
400 |
setArray(elements); |
401 |
} |
402 |
return oldValue; |
403 |
} |
404 |
} |
405 |
|
406 |
/** |
407 |
* Appends the specified element to the end of this list. |
408 |
* |
409 |
* @param e element to be appended to this list |
410 |
* @return {@code true} (as specified by {@link Collection#add}) |
411 |
*/ |
412 |
public boolean add(E e) { |
413 |
synchronized (lock) { |
414 |
Object[] elements = getArray(); |
415 |
int len = elements.length; |
416 |
Object[] newElements = Arrays.copyOf(elements, len + 1); |
417 |
newElements[len] = e; |
418 |
setArray(newElements); |
419 |
return true; |
420 |
} |
421 |
} |
422 |
|
423 |
/** |
424 |
* Inserts the specified element at the specified position in this |
425 |
* list. Shifts the element currently at that position (if any) and |
426 |
* any subsequent elements to the right (adds one to their indices). |
427 |
* |
428 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
429 |
*/ |
430 |
public void add(int index, E element) { |
431 |
synchronized (lock) { |
432 |
Object[] elements = getArray(); |
433 |
int len = elements.length; |
434 |
if (index > len || index < 0) |
435 |
throw new IndexOutOfBoundsException(outOfBounds(index, len)); |
436 |
Object[] newElements; |
437 |
int numMoved = len - index; |
438 |
if (numMoved == 0) |
439 |
newElements = Arrays.copyOf(elements, len + 1); |
440 |
else { |
441 |
newElements = new Object[len + 1]; |
442 |
System.arraycopy(elements, 0, newElements, 0, index); |
443 |
System.arraycopy(elements, index, newElements, index + 1, |
444 |
numMoved); |
445 |
} |
446 |
newElements[index] = element; |
447 |
setArray(newElements); |
448 |
} |
449 |
} |
450 |
|
451 |
/** |
452 |
* Removes the element at the specified position in this list. |
453 |
* Shifts any subsequent elements to the left (subtracts one from their |
454 |
* indices). Returns the element that was removed from the list. |
455 |
* |
456 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
457 |
*/ |
458 |
public E remove(int index) { |
459 |
synchronized (lock) { |
460 |
Object[] elements = getArray(); |
461 |
int len = elements.length; |
462 |
E oldValue = elementAt(elements, index); |
463 |
int numMoved = len - index - 1; |
464 |
if (numMoved == 0) |
465 |
setArray(Arrays.copyOf(elements, len - 1)); |
466 |
else { |
467 |
Object[] newElements = new Object[len - 1]; |
468 |
System.arraycopy(elements, 0, newElements, 0, index); |
469 |
System.arraycopy(elements, index + 1, newElements, index, |
470 |
numMoved); |
471 |
setArray(newElements); |
472 |
} |
473 |
return oldValue; |
474 |
} |
475 |
} |
476 |
|
477 |
/** |
478 |
* Removes the first occurrence of the specified element from this list, |
479 |
* if it is present. If this list does not contain the element, it is |
480 |
* unchanged. More formally, removes the element with the lowest index |
481 |
* {@code i} such that {@code Objects.equals(o, get(i))} |
482 |
* (if such an element exists). Returns {@code true} if this list |
483 |
* contained the specified element (or equivalently, if this list |
484 |
* changed as a result of the call). |
485 |
* |
486 |
* @param o element to be removed from this list, if present |
487 |
* @return {@code true} if this list contained the specified element |
488 |
*/ |
489 |
public boolean remove(Object o) { |
490 |
Object[] snapshot = getArray(); |
491 |
int index = indexOf(o, snapshot, 0, snapshot.length); |
492 |
return (index < 0) ? false : remove(o, snapshot, index); |
493 |
} |
494 |
|
495 |
/** |
496 |
* A version of remove(Object) using the strong hint that given |
497 |
* recent snapshot contains o at the given index. |
498 |
*/ |
499 |
private boolean remove(Object o, Object[] snapshot, int index) { |
500 |
synchronized (lock) { |
501 |
Object[] current = getArray(); |
502 |
int len = current.length; |
503 |
if (snapshot != current) findIndex: { |
504 |
int prefix = Math.min(index, len); |
505 |
for (int i = 0; i < prefix; i++) { |
506 |
if (current[i] != snapshot[i] |
507 |
&& Objects.equals(o, current[i])) { |
508 |
index = i; |
509 |
break findIndex; |
510 |
} |
511 |
} |
512 |
if (index >= len) |
513 |
return false; |
514 |
if (current[index] == o) |
515 |
break findIndex; |
516 |
index = indexOf(o, current, index, len); |
517 |
if (index < 0) |
518 |
return false; |
519 |
} |
520 |
Object[] newElements = new Object[len - 1]; |
521 |
System.arraycopy(current, 0, newElements, 0, index); |
522 |
System.arraycopy(current, index + 1, |
523 |
newElements, index, |
524 |
len - index - 1); |
525 |
setArray(newElements); |
526 |
return true; |
527 |
} |
528 |
} |
529 |
|
530 |
/** |
531 |
* Removes from this list all of the elements whose index is between |
532 |
* {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. |
533 |
* Shifts any succeeding elements to the left (reduces their index). |
534 |
* This call shortens the list by {@code (toIndex - fromIndex)} elements. |
535 |
* (If {@code toIndex==fromIndex}, this operation has no effect.) |
536 |
* |
537 |
* @param fromIndex index of first element to be removed |
538 |
* @param toIndex index after last element to be removed |
539 |
* @throws IndexOutOfBoundsException if fromIndex or toIndex out of range |
540 |
* ({@code fromIndex < 0 || toIndex > size() || toIndex < fromIndex}) |
541 |
*/ |
542 |
void removeRange(int fromIndex, int toIndex) { |
543 |
synchronized (lock) { |
544 |
Object[] elements = getArray(); |
545 |
int len = elements.length; |
546 |
|
547 |
if (fromIndex < 0 || toIndex > len || toIndex < fromIndex) |
548 |
throw new IndexOutOfBoundsException(); |
549 |
int newlen = len - (toIndex - fromIndex); |
550 |
int numMoved = len - toIndex; |
551 |
if (numMoved == 0) |
552 |
setArray(Arrays.copyOf(elements, newlen)); |
553 |
else { |
554 |
Object[] newElements = new Object[newlen]; |
555 |
System.arraycopy(elements, 0, newElements, 0, fromIndex); |
556 |
System.arraycopy(elements, toIndex, newElements, |
557 |
fromIndex, numMoved); |
558 |
setArray(newElements); |
559 |
} |
560 |
} |
561 |
} |
562 |
|
563 |
/** |
564 |
* Appends the element, if not present. |
565 |
* |
566 |
* @param e element to be added to this list, if absent |
567 |
* @return {@code true} if the element was added |
568 |
*/ |
569 |
public boolean addIfAbsent(E e) { |
570 |
Object[] snapshot = getArray(); |
571 |
return indexOf(e, snapshot, 0, snapshot.length) >= 0 ? false : |
572 |
addIfAbsent(e, snapshot); |
573 |
} |
574 |
|
575 |
/** |
576 |
* A version of addIfAbsent using the strong hint that given |
577 |
* recent snapshot does not contain e. |
578 |
*/ |
579 |
private boolean addIfAbsent(E e, Object[] snapshot) { |
580 |
synchronized (lock) { |
581 |
Object[] current = getArray(); |
582 |
int len = current.length; |
583 |
if (snapshot != current) { |
584 |
// Optimize for lost race to another addXXX operation |
585 |
int common = Math.min(snapshot.length, len); |
586 |
for (int i = 0; i < common; i++) |
587 |
if (current[i] != snapshot[i] |
588 |
&& Objects.equals(e, current[i])) |
589 |
return false; |
590 |
if (indexOf(e, current, common, len) >= 0) |
591 |
return false; |
592 |
} |
593 |
Object[] newElements = Arrays.copyOf(current, len + 1); |
594 |
newElements[len] = e; |
595 |
setArray(newElements); |
596 |
return true; |
597 |
} |
598 |
} |
599 |
|
600 |
/** |
601 |
* Returns {@code true} if this list contains all of the elements of the |
602 |
* specified collection. |
603 |
* |
604 |
* @param c collection to be checked for containment in this list |
605 |
* @return {@code true} if this list contains all of the elements of the |
606 |
* specified collection |
607 |
* @throws NullPointerException if the specified collection is null |
608 |
* @see #contains(Object) |
609 |
*/ |
610 |
public boolean containsAll(Collection<?> c) { |
611 |
Object[] elements = getArray(); |
612 |
int len = elements.length; |
613 |
for (Object e : c) { |
614 |
if (indexOf(e, elements, 0, len) < 0) |
615 |
return false; |
616 |
} |
617 |
return true; |
618 |
} |
619 |
|
620 |
/** |
621 |
* Removes from this list all of its elements that are contained in |
622 |
* the specified collection. This is a particularly expensive operation |
623 |
* in this class because of the need for an internal temporary array. |
624 |
* |
625 |
* @param c collection containing elements to be removed from this list |
626 |
* @return {@code true} if this list changed as a result of the call |
627 |
* @throws ClassCastException if the class of an element of this list |
628 |
* is incompatible with the specified collection |
629 |
* (<a href="{@docRoot}/../api/java/util/Collection.html#optional-restrictions">optional</a>) |
630 |
* @throws NullPointerException if this list contains a null element and the |
631 |
* specified collection does not permit null elements |
632 |
* (<a href="{@docRoot}/../api/java/util/Collection.html#optional-restrictions">optional</a>), |
633 |
* or if the specified collection is null |
634 |
* @see #remove(Object) |
635 |
*/ |
636 |
public boolean removeAll(Collection<?> c) { |
637 |
Objects.requireNonNull(c); |
638 |
return bulkRemove(e -> c.contains(e)); |
639 |
} |
640 |
|
641 |
/** |
642 |
* Retains only the elements in this list that are contained in the |
643 |
* specified collection. In other words, removes from this list all of |
644 |
* its elements that are not contained in the specified collection. |
645 |
* |
646 |
* @param c collection containing elements to be retained in this list |
647 |
* @return {@code true} if this list changed as a result of the call |
648 |
* @throws ClassCastException if the class of an element of this list |
649 |
* is incompatible with the specified collection |
650 |
* (<a href="{@docRoot}/../api/java/util/Collection.html#optional-restrictions">optional</a>) |
651 |
* @throws NullPointerException if this list contains a null element and the |
652 |
* specified collection does not permit null elements |
653 |
* (<a href="{@docRoot}/../api/java/util/Collection.html#optional-restrictions">optional</a>), |
654 |
* or if the specified collection is null |
655 |
* @see #remove(Object) |
656 |
*/ |
657 |
public boolean retainAll(Collection<?> c) { |
658 |
Objects.requireNonNull(c); |
659 |
return bulkRemove(e -> !c.contains(e)); |
660 |
} |
661 |
|
662 |
/** |
663 |
* Appends all of the elements in the specified collection that |
664 |
* are not already contained in this list, to the end of |
665 |
* this list, in the order that they are returned by the |
666 |
* specified collection's iterator. |
667 |
* |
668 |
* @param c collection containing elements to be added to this list |
669 |
* @return the number of elements added |
670 |
* @throws NullPointerException if the specified collection is null |
671 |
* @see #addIfAbsent(Object) |
672 |
*/ |
673 |
public int addAllAbsent(Collection<? extends E> c) { |
674 |
Object[] cs = c.toArray(); |
675 |
if (cs.length == 0) |
676 |
return 0; |
677 |
synchronized (lock) { |
678 |
Object[] elements = getArray(); |
679 |
int len = elements.length; |
680 |
int added = 0; |
681 |
// uniquify and compact elements in cs |
682 |
for (int i = 0; i < cs.length; ++i) { |
683 |
Object e = cs[i]; |
684 |
if (indexOf(e, elements, 0, len) < 0 && |
685 |
indexOf(e, cs, 0, added) < 0) |
686 |
cs[added++] = e; |
687 |
} |
688 |
if (added > 0) { |
689 |
Object[] newElements = Arrays.copyOf(elements, len + added); |
690 |
System.arraycopy(cs, 0, newElements, len, added); |
691 |
setArray(newElements); |
692 |
} |
693 |
return added; |
694 |
} |
695 |
} |
696 |
|
697 |
/** |
698 |
* Removes all of the elements from this list. |
699 |
* The list will be empty after this call returns. |
700 |
*/ |
701 |
public void clear() { |
702 |
synchronized (lock) { |
703 |
setArray(new Object[0]); |
704 |
} |
705 |
} |
706 |
|
707 |
/** |
708 |
* Appends all of the elements in the specified collection to the end |
709 |
* of this list, in the order that they are returned by the specified |
710 |
* collection's iterator. |
711 |
* |
712 |
* @param c collection containing elements to be added to this list |
713 |
* @return {@code true} if this list changed as a result of the call |
714 |
* @throws NullPointerException if the specified collection is null |
715 |
* @see #add(Object) |
716 |
*/ |
717 |
public boolean addAll(Collection<? extends E> c) { |
718 |
Object[] cs = (c.getClass() == CopyOnWriteArrayList.class) ? |
719 |
((CopyOnWriteArrayList<?>)c).getArray() : c.toArray(); |
720 |
if (cs.length == 0) |
721 |
return false; |
722 |
synchronized (lock) { |
723 |
Object[] elements = getArray(); |
724 |
int len = elements.length; |
725 |
if (len == 0 && cs.getClass() == Object[].class) |
726 |
setArray(cs); |
727 |
else { |
728 |
Object[] newElements = Arrays.copyOf(elements, len + cs.length); |
729 |
System.arraycopy(cs, 0, newElements, len, cs.length); |
730 |
setArray(newElements); |
731 |
} |
732 |
return true; |
733 |
} |
734 |
} |
735 |
|
736 |
/** |
737 |
* Inserts all of the elements in the specified collection into this |
738 |
* list, starting at the specified position. Shifts the element |
739 |
* currently at that position (if any) and any subsequent elements to |
740 |
* the right (increases their indices). The new elements will appear |
741 |
* in this list in the order that they are returned by the |
742 |
* specified collection's iterator. |
743 |
* |
744 |
* @param index index at which to insert the first element |
745 |
* from the specified collection |
746 |
* @param c collection containing elements to be added to this list |
747 |
* @return {@code true} if this list changed as a result of the call |
748 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
749 |
* @throws NullPointerException if the specified collection is null |
750 |
* @see #add(int,Object) |
751 |
*/ |
752 |
public boolean addAll(int index, Collection<? extends E> c) { |
753 |
Object[] cs = c.toArray(); |
754 |
synchronized (lock) { |
755 |
Object[] elements = getArray(); |
756 |
int len = elements.length; |
757 |
if (index > len || index < 0) |
758 |
throw new IndexOutOfBoundsException(outOfBounds(index, len)); |
759 |
if (cs.length == 0) |
760 |
return false; |
761 |
int numMoved = len - index; |
762 |
Object[] newElements; |
763 |
if (numMoved == 0) |
764 |
newElements = Arrays.copyOf(elements, len + cs.length); |
765 |
else { |
766 |
newElements = new Object[len + cs.length]; |
767 |
System.arraycopy(elements, 0, newElements, 0, index); |
768 |
System.arraycopy(elements, index, |
769 |
newElements, index + cs.length, |
770 |
numMoved); |
771 |
} |
772 |
System.arraycopy(cs, 0, newElements, index, cs.length); |
773 |
setArray(newElements); |
774 |
return true; |
775 |
} |
776 |
} |
777 |
|
778 |
public void forEach(Consumer<? super E> action) { |
779 |
if (action == null) throw new NullPointerException(); |
780 |
for (Object x : getArray()) { |
781 |
@SuppressWarnings("unchecked") E e = (E) x; |
782 |
action.accept(e); |
783 |
} |
784 |
} |
785 |
|
786 |
public boolean removeIf(Predicate<? super E> filter) { |
787 |
if (filter == null) throw new NullPointerException(); |
788 |
return bulkRemove(filter); |
789 |
} |
790 |
|
791 |
// A tiny bit set implementation |
792 |
|
793 |
private static long[] nBits(int n) { |
794 |
return new long[((n - 1) >> 6) + 1]; |
795 |
} |
796 |
private static void setBit(long[] bits, int i) { |
797 |
bits[i >> 6] |= 1L << i; |
798 |
} |
799 |
private static boolean isClear(long[] bits, int i) { |
800 |
return (bits[i >> 6] & (1L << i)) == 0; |
801 |
} |
802 |
|
803 |
private boolean bulkRemove(Predicate<? super E> filter) { |
804 |
synchronized (lock) { |
805 |
return bulkRemove(filter, 0, getArray().length); |
806 |
} |
807 |
} |
808 |
|
809 |
boolean bulkRemove(Predicate<? super E> filter, int i, int end) { |
810 |
// assert Thread.holdsLock(lock); |
811 |
final Object[] es = getArray(); |
812 |
// Optimize for initial run of survivors |
813 |
for (; i < end && !filter.test(elementAt(es, i)); i++) |
814 |
; |
815 |
if (i < end) { |
816 |
final int beg = i; |
817 |
final long[] deathRow = nBits(end - beg); |
818 |
int deleted = 1; |
819 |
deathRow[0] = 1L; // set bit 0 |
820 |
for (i = beg + 1; i < end; i++) |
821 |
if (filter.test(elementAt(es, i))) { |
822 |
setBit(deathRow, i - beg); |
823 |
deleted++; |
824 |
} |
825 |
// Did filter reentrantly modify the list? |
826 |
if (es != getArray()) |
827 |
throw new ConcurrentModificationException(); |
828 |
final Object[] newElts = Arrays.copyOf(es, es.length - deleted); |
829 |
int w = beg; |
830 |
for (i = beg; i < end; i++) |
831 |
if (isClear(deathRow, i - beg)) |
832 |
newElts[w++] = es[i]; |
833 |
System.arraycopy(es, i, newElts, w, es.length - i); |
834 |
setArray(newElts); |
835 |
return true; |
836 |
} else { |
837 |
if (es != getArray()) |
838 |
throw new ConcurrentModificationException(); |
839 |
return false; |
840 |
} |
841 |
} |
842 |
|
843 |
public void replaceAll(UnaryOperator<E> operator) { |
844 |
if (operator == null) throw new NullPointerException(); |
845 |
synchronized (lock) { |
846 |
replaceAll(operator, 0, getArray().length); |
847 |
} |
848 |
} |
849 |
|
850 |
void replaceAll(UnaryOperator<E> operator, int i, int end) { |
851 |
// assert Thread.holdsLock(lock); |
852 |
final Object[] es = getArray().clone(); |
853 |
for (; i < end; i++) |
854 |
es[i] = operator.apply(elementAt(es, i)); |
855 |
setArray(es); |
856 |
} |
857 |
|
858 |
public void sort(Comparator<? super E> c) { |
859 |
synchronized (lock) { |
860 |
sort(c, 0, getArray().length); |
861 |
} |
862 |
} |
863 |
|
864 |
@SuppressWarnings("unchecked") |
865 |
void sort(Comparator<? super E> c, int i, int end) { |
866 |
// assert Thread.holdsLock(lock); |
867 |
final Object[] es = getArray().clone(); |
868 |
Arrays.sort(es, i, end, (Comparator<Object>)c); |
869 |
setArray(es); |
870 |
} |
871 |
|
872 |
/** |
873 |
* Saves this list to a stream (that is, serializes it). |
874 |
* |
875 |
* @param s the stream |
876 |
* @throws java.io.IOException if an I/O error occurs |
877 |
* @serialData The length of the array backing the list is emitted |
878 |
* (int), followed by all of its elements (each an Object) |
879 |
* in the proper order. |
880 |
*/ |
881 |
private void writeObject(java.io.ObjectOutputStream s) |
882 |
throws java.io.IOException { |
883 |
|
884 |
s.defaultWriteObject(); |
885 |
|
886 |
Object[] elements = getArray(); |
887 |
// Write out array length |
888 |
s.writeInt(elements.length); |
889 |
|
890 |
// Write out all elements in the proper order. |
891 |
for (Object element : elements) |
892 |
s.writeObject(element); |
893 |
} |
894 |
|
895 |
/** |
896 |
* Reconstitutes this list from a stream (that is, deserializes it). |
897 |
* @param s the stream |
898 |
* @throws ClassNotFoundException if the class of a serialized object |
899 |
* could not be found |
900 |
* @throws java.io.IOException if an I/O error occurs |
901 |
*/ |
902 |
private void readObject(java.io.ObjectInputStream s) |
903 |
throws java.io.IOException, ClassNotFoundException { |
904 |
|
905 |
s.defaultReadObject(); |
906 |
|
907 |
// bind to new lock |
908 |
resetLock(); |
909 |
|
910 |
// Read in array length and allocate array |
911 |
int len = s.readInt(); |
912 |
Object[] elements = new Object[len]; |
913 |
|
914 |
// Read in all elements in the proper order. |
915 |
for (int i = 0; i < len; i++) |
916 |
elements[i] = s.readObject(); |
917 |
setArray(elements); |
918 |
} |
919 |
|
920 |
/** |
921 |
* Returns a string representation of this list. The string |
922 |
* representation consists of the string representations of the list's |
923 |
* elements in the order they are returned by its iterator, enclosed in |
924 |
* square brackets ({@code "[]"}). Adjacent elements are separated by |
925 |
* the characters {@code ", "} (comma and space). Elements are |
926 |
* converted to strings as by {@link String#valueOf(Object)}. |
927 |
* |
928 |
* @return a string representation of this list |
929 |
*/ |
930 |
public String toString() { |
931 |
return Arrays.toString(getArray()); |
932 |
} |
933 |
|
934 |
/** |
935 |
* Compares the specified object with this list for equality. |
936 |
* Returns {@code true} if the specified object is the same object |
937 |
* as this object, or if it is also a {@link List} and the sequence |
938 |
* of elements returned by an {@linkplain List#iterator() iterator} |
939 |
* over the specified list is the same as the sequence returned by |
940 |
* an iterator over this list. The two sequences are considered to |
941 |
* be the same if they have the same length and corresponding |
942 |
* elements at the same position in the sequence are <em>equal</em>. |
943 |
* Two elements {@code e1} and {@code e2} are considered |
944 |
* <em>equal</em> if {@code Objects.equals(e1, e2)}. |
945 |
* |
946 |
* @param o the object to be compared for equality with this list |
947 |
* @return {@code true} if the specified object is equal to this list |
948 |
*/ |
949 |
public boolean equals(Object o) { |
950 |
if (o == this) |
951 |
return true; |
952 |
if (!(o instanceof List)) |
953 |
return false; |
954 |
|
955 |
List<?> list = (List<?>)o; |
956 |
Iterator<?> it = list.iterator(); |
957 |
Object[] elements = getArray(); |
958 |
for (int i = 0, len = elements.length; i < len; i++) |
959 |
if (!it.hasNext() || !Objects.equals(elements[i], it.next())) |
960 |
return false; |
961 |
if (it.hasNext()) |
962 |
return false; |
963 |
return true; |
964 |
} |
965 |
|
966 |
/** |
967 |
* Returns the hash code value for this list. |
968 |
* |
969 |
* <p>This implementation uses the definition in {@link List#hashCode}. |
970 |
* |
971 |
* @return the hash code value for this list |
972 |
*/ |
973 |
public int hashCode() { |
974 |
int hashCode = 1; |
975 |
for (Object x : getArray()) |
976 |
hashCode = 31 * hashCode + (x == null ? 0 : x.hashCode()); |
977 |
return hashCode; |
978 |
} |
979 |
|
980 |
/** |
981 |
* Returns an iterator over the elements in this list in proper sequence. |
982 |
* |
983 |
* <p>The returned iterator provides a snapshot of the state of the list |
984 |
* when the iterator was constructed. No synchronization is needed while |
985 |
* traversing the iterator. The iterator does <em>NOT</em> support the |
986 |
* {@code remove} method. |
987 |
* |
988 |
* @return an iterator over the elements in this list in proper sequence |
989 |
*/ |
990 |
public Iterator<E> iterator() { |
991 |
return new COWIterator<E>(getArray(), 0); |
992 |
} |
993 |
|
994 |
/** |
995 |
* {@inheritDoc} |
996 |
* |
997 |
* <p>The returned iterator provides a snapshot of the state of the list |
998 |
* when the iterator was constructed. No synchronization is needed while |
999 |
* traversing the iterator. The iterator does <em>NOT</em> support the |
1000 |
* {@code remove}, {@code set} or {@code add} methods. |
1001 |
*/ |
1002 |
public ListIterator<E> listIterator() { |
1003 |
return new COWIterator<E>(getArray(), 0); |
1004 |
} |
1005 |
|
1006 |
/** |
1007 |
* {@inheritDoc} |
1008 |
* |
1009 |
* <p>The returned iterator provides a snapshot of the state of the list |
1010 |
* when the iterator was constructed. No synchronization is needed while |
1011 |
* traversing the iterator. The iterator does <em>NOT</em> support the |
1012 |
* {@code remove}, {@code set} or {@code add} methods. |
1013 |
* |
1014 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
1015 |
*/ |
1016 |
public ListIterator<E> listIterator(int index) { |
1017 |
Object[] elements = getArray(); |
1018 |
int len = elements.length; |
1019 |
if (index < 0 || index > len) |
1020 |
throw new IndexOutOfBoundsException(outOfBounds(index, len)); |
1021 |
|
1022 |
return new COWIterator<E>(elements, index); |
1023 |
} |
1024 |
|
1025 |
/** |
1026 |
* Returns a {@link Spliterator} over the elements in this list. |
1027 |
* |
1028 |
* <p>The {@code Spliterator} reports {@link Spliterator#IMMUTABLE}, |
1029 |
* {@link Spliterator#ORDERED}, {@link Spliterator#SIZED}, and |
1030 |
* {@link Spliterator#SUBSIZED}. |
1031 |
* |
1032 |
* <p>The spliterator provides a snapshot of the state of the list |
1033 |
* when the spliterator was constructed. No synchronization is needed while |
1034 |
* operating on the spliterator. |
1035 |
* |
1036 |
* @return a {@code Spliterator} over the elements in this list |
1037 |
* @since 1.8 |
1038 |
*/ |
1039 |
public Spliterator<E> spliterator() { |
1040 |
return Spliterators.spliterator |
1041 |
(getArray(), Spliterator.IMMUTABLE | Spliterator.ORDERED); |
1042 |
} |
1043 |
|
1044 |
static final class COWIterator<E> implements ListIterator<E> { |
1045 |
/** Snapshot of the array */ |
1046 |
private final Object[] snapshot; |
1047 |
/** Index of element to be returned by subsequent call to next. */ |
1048 |
private int cursor; |
1049 |
|
1050 |
COWIterator(Object[] elements, int initialCursor) { |
1051 |
cursor = initialCursor; |
1052 |
snapshot = elements; |
1053 |
} |
1054 |
|
1055 |
public boolean hasNext() { |
1056 |
return cursor < snapshot.length; |
1057 |
} |
1058 |
|
1059 |
public boolean hasPrevious() { |
1060 |
return cursor > 0; |
1061 |
} |
1062 |
|
1063 |
@SuppressWarnings("unchecked") |
1064 |
public E next() { |
1065 |
if (! hasNext()) |
1066 |
throw new NoSuchElementException(); |
1067 |
return (E) snapshot[cursor++]; |
1068 |
} |
1069 |
|
1070 |
@SuppressWarnings("unchecked") |
1071 |
public E previous() { |
1072 |
if (! hasPrevious()) |
1073 |
throw new NoSuchElementException(); |
1074 |
return (E) snapshot[--cursor]; |
1075 |
} |
1076 |
|
1077 |
public int nextIndex() { |
1078 |
return cursor; |
1079 |
} |
1080 |
|
1081 |
public int previousIndex() { |
1082 |
return cursor-1; |
1083 |
} |
1084 |
|
1085 |
/** |
1086 |
* Not supported. Always throws UnsupportedOperationException. |
1087 |
* @throws UnsupportedOperationException always; {@code remove} |
1088 |
* is not supported by this iterator. |
1089 |
*/ |
1090 |
public void remove() { |
1091 |
throw new UnsupportedOperationException(); |
1092 |
} |
1093 |
|
1094 |
/** |
1095 |
* Not supported. Always throws UnsupportedOperationException. |
1096 |
* @throws UnsupportedOperationException always; {@code set} |
1097 |
* is not supported by this iterator. |
1098 |
*/ |
1099 |
public void set(E e) { |
1100 |
throw new UnsupportedOperationException(); |
1101 |
} |
1102 |
|
1103 |
/** |
1104 |
* Not supported. Always throws UnsupportedOperationException. |
1105 |
* @throws UnsupportedOperationException always; {@code add} |
1106 |
* is not supported by this iterator. |
1107 |
*/ |
1108 |
public void add(E e) { |
1109 |
throw new UnsupportedOperationException(); |
1110 |
} |
1111 |
|
1112 |
@Override |
1113 |
@SuppressWarnings("unchecked") |
1114 |
public void forEachRemaining(Consumer<? super E> action) { |
1115 |
Objects.requireNonNull(action); |
1116 |
final int size = snapshot.length; |
1117 |
for (int i = cursor; i < size; i++) { |
1118 |
action.accept((E) snapshot[i]); |
1119 |
} |
1120 |
cursor = size; |
1121 |
} |
1122 |
} |
1123 |
|
1124 |
/** |
1125 |
* Returns a view of the portion of this list between |
1126 |
* {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. |
1127 |
* The returned list is backed by this list, so changes in the |
1128 |
* returned list are reflected in this list. |
1129 |
* |
1130 |
* <p>The semantics of the list returned by this method become |
1131 |
* undefined if the backing list (i.e., this list) is modified in |
1132 |
* any way other than via the returned list. |
1133 |
* |
1134 |
* @param fromIndex low endpoint (inclusive) of the subList |
1135 |
* @param toIndex high endpoint (exclusive) of the subList |
1136 |
* @return a view of the specified range within this list |
1137 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
1138 |
*/ |
1139 |
public List<E> subList(int fromIndex, int toIndex) { |
1140 |
synchronized (lock) { |
1141 |
Object[] elements = getArray(); |
1142 |
int len = elements.length; |
1143 |
if (fromIndex < 0 || toIndex > len || fromIndex > toIndex) |
1144 |
throw new IndexOutOfBoundsException(); |
1145 |
return new COWSubList<E>(this, fromIndex, toIndex); |
1146 |
} |
1147 |
} |
1148 |
|
1149 |
/** |
1150 |
* Sublist for CopyOnWriteArrayList. |
1151 |
*/ |
1152 |
private static class COWSubList<E> |
1153 |
extends AbstractList<E> |
1154 |
implements RandomAccess |
1155 |
{ |
1156 |
private final CopyOnWriteArrayList<E> l; |
1157 |
private final int offset; |
1158 |
private int size; |
1159 |
private Object[] expectedArray; |
1160 |
|
1161 |
// only call this holding l's lock |
1162 |
COWSubList(CopyOnWriteArrayList<E> list, |
1163 |
int fromIndex, int toIndex) { |
1164 |
// assert Thread.holdsLock(list.lock); |
1165 |
l = list; |
1166 |
expectedArray = l.getArray(); |
1167 |
offset = fromIndex; |
1168 |
size = toIndex - fromIndex; |
1169 |
} |
1170 |
|
1171 |
// only call this holding l's lock |
1172 |
private void checkForComodification() { |
1173 |
// assert Thread.holdsLock(l.lock); |
1174 |
if (l.getArray() != expectedArray) |
1175 |
throw new ConcurrentModificationException(); |
1176 |
} |
1177 |
|
1178 |
private Object[] getArrayChecked() { |
1179 |
// assert Thread.holdsLock(l.lock); |
1180 |
Object[] a = l.getArray(); |
1181 |
if (a != expectedArray) |
1182 |
throw new ConcurrentModificationException(); |
1183 |
return a; |
1184 |
} |
1185 |
|
1186 |
// only call this holding l's lock |
1187 |
private void rangeCheck(int index) { |
1188 |
// assert Thread.holdsLock(l.lock); |
1189 |
if (index < 0 || index >= size) |
1190 |
throw new IndexOutOfBoundsException(outOfBounds(index, size)); |
1191 |
} |
1192 |
|
1193 |
public E set(int index, E element) { |
1194 |
synchronized (l.lock) { |
1195 |
rangeCheck(index); |
1196 |
checkForComodification(); |
1197 |
E x = l.set(offset + index, element); |
1198 |
expectedArray = l.getArray(); |
1199 |
return x; |
1200 |
} |
1201 |
} |
1202 |
|
1203 |
public E get(int index) { |
1204 |
synchronized (l.lock) { |
1205 |
rangeCheck(index); |
1206 |
checkForComodification(); |
1207 |
return l.get(offset + index); |
1208 |
} |
1209 |
} |
1210 |
|
1211 |
public int size() { |
1212 |
synchronized (l.lock) { |
1213 |
checkForComodification(); |
1214 |
return size; |
1215 |
} |
1216 |
} |
1217 |
|
1218 |
public boolean add(E element) { |
1219 |
synchronized (l.lock) { |
1220 |
checkForComodification(); |
1221 |
l.add(offset + size, element); |
1222 |
expectedArray = l.getArray(); |
1223 |
size++; |
1224 |
} |
1225 |
return true; |
1226 |
} |
1227 |
|
1228 |
public void add(int index, E element) { |
1229 |
synchronized (l.lock) { |
1230 |
checkForComodification(); |
1231 |
if (index < 0 || index > size) |
1232 |
throw new IndexOutOfBoundsException |
1233 |
(outOfBounds(index, size)); |
1234 |
l.add(offset + index, element); |
1235 |
expectedArray = l.getArray(); |
1236 |
size++; |
1237 |
} |
1238 |
} |
1239 |
|
1240 |
public boolean addAll(Collection<? extends E> c) { |
1241 |
synchronized (l.lock) { |
1242 |
final Object[] oldArray = getArrayChecked(); |
1243 |
boolean modified = l.addAll(offset + size, c); |
1244 |
size += (expectedArray = l.getArray()).length - oldArray.length; |
1245 |
return modified; |
1246 |
} |
1247 |
} |
1248 |
|
1249 |
public void clear() { |
1250 |
synchronized (l.lock) { |
1251 |
checkForComodification(); |
1252 |
l.removeRange(offset, offset + size); |
1253 |
expectedArray = l.getArray(); |
1254 |
size = 0; |
1255 |
} |
1256 |
} |
1257 |
|
1258 |
public E remove(int index) { |
1259 |
synchronized (l.lock) { |
1260 |
rangeCheck(index); |
1261 |
checkForComodification(); |
1262 |
E result = l.remove(offset + index); |
1263 |
expectedArray = l.getArray(); |
1264 |
size--; |
1265 |
return result; |
1266 |
} |
1267 |
} |
1268 |
|
1269 |
public boolean remove(Object o) { |
1270 |
synchronized (l.lock) { |
1271 |
checkForComodification(); |
1272 |
int index = indexOf(o); |
1273 |
if (index == -1) |
1274 |
return false; |
1275 |
remove(index); |
1276 |
return true; |
1277 |
} |
1278 |
} |
1279 |
|
1280 |
public Iterator<E> iterator() { |
1281 |
synchronized (l.lock) { |
1282 |
checkForComodification(); |
1283 |
return new COWSubListIterator<E>(l, 0, offset, size); |
1284 |
} |
1285 |
} |
1286 |
|
1287 |
public ListIterator<E> listIterator(int index) { |
1288 |
synchronized (l.lock) { |
1289 |
checkForComodification(); |
1290 |
if (index < 0 || index > size) |
1291 |
throw new IndexOutOfBoundsException |
1292 |
(outOfBounds(index, size)); |
1293 |
return new COWSubListIterator<E>(l, index, offset, size); |
1294 |
} |
1295 |
} |
1296 |
|
1297 |
public List<E> subList(int fromIndex, int toIndex) { |
1298 |
synchronized (l.lock) { |
1299 |
checkForComodification(); |
1300 |
if (fromIndex < 0 || toIndex > size || fromIndex > toIndex) |
1301 |
throw new IndexOutOfBoundsException(); |
1302 |
return new COWSubList<E>(l, fromIndex + offset, |
1303 |
toIndex + offset); |
1304 |
} |
1305 |
} |
1306 |
|
1307 |
public void forEach(Consumer<? super E> action) { |
1308 |
if (action == null) throw new NullPointerException(); |
1309 |
int i, end; final Object[] es; |
1310 |
synchronized (l.lock) { |
1311 |
es = getArrayChecked(); |
1312 |
i = offset; |
1313 |
end = i + size; |
1314 |
} |
1315 |
for (; i < end; i++) |
1316 |
action.accept(elementAt(es, i)); |
1317 |
} |
1318 |
|
1319 |
public void replaceAll(UnaryOperator<E> operator) { |
1320 |
if (operator == null) throw new NullPointerException(); |
1321 |
synchronized (l.lock) { |
1322 |
checkForComodification(); |
1323 |
l.replaceAll(operator, offset, offset + size); |
1324 |
expectedArray = l.getArray(); |
1325 |
} |
1326 |
} |
1327 |
|
1328 |
public void sort(Comparator<? super E> c) { |
1329 |
synchronized (l.lock) { |
1330 |
checkForComodification(); |
1331 |
l.sort(c, offset, offset + size); |
1332 |
expectedArray = l.getArray(); |
1333 |
} |
1334 |
} |
1335 |
|
1336 |
public boolean removeAll(Collection<?> c) { |
1337 |
Objects.requireNonNull(c); |
1338 |
return bulkRemove(e -> c.contains(e)); |
1339 |
} |
1340 |
|
1341 |
public boolean retainAll(Collection<?> c) { |
1342 |
Objects.requireNonNull(c); |
1343 |
return bulkRemove(e -> !c.contains(e)); |
1344 |
} |
1345 |
|
1346 |
public boolean removeIf(Predicate<? super E> filter) { |
1347 |
Objects.requireNonNull(filter); |
1348 |
return bulkRemove(filter); |
1349 |
} |
1350 |
|
1351 |
private boolean bulkRemove(Predicate<? super E> filter) { |
1352 |
synchronized (l.lock) { |
1353 |
final Object[] oldArray = getArrayChecked(); |
1354 |
boolean modified = l.bulkRemove(filter, offset, offset + size); |
1355 |
size += (expectedArray = l.getArray()).length - oldArray.length; |
1356 |
return modified; |
1357 |
} |
1358 |
} |
1359 |
|
1360 |
public Spliterator<E> spliterator() { |
1361 |
synchronized (l.lock) { |
1362 |
return Spliterators.spliterator( |
1363 |
getArrayChecked(), offset, offset + size, |
1364 |
Spliterator.IMMUTABLE | Spliterator.ORDERED); |
1365 |
} |
1366 |
} |
1367 |
|
1368 |
} |
1369 |
|
1370 |
private static class COWSubListIterator<E> implements ListIterator<E> { |
1371 |
private final ListIterator<E> it; |
1372 |
private final int offset; |
1373 |
private final int size; |
1374 |
|
1375 |
COWSubListIterator(List<E> l, int index, int offset, int size) { |
1376 |
this.offset = offset; |
1377 |
this.size = size; |
1378 |
it = l.listIterator(index+offset); |
1379 |
} |
1380 |
|
1381 |
public boolean hasNext() { |
1382 |
return nextIndex() < size; |
1383 |
} |
1384 |
|
1385 |
public E next() { |
1386 |
if (hasNext()) |
1387 |
return it.next(); |
1388 |
else |
1389 |
throw new NoSuchElementException(); |
1390 |
} |
1391 |
|
1392 |
public boolean hasPrevious() { |
1393 |
return previousIndex() >= 0; |
1394 |
} |
1395 |
|
1396 |
public E previous() { |
1397 |
if (hasPrevious()) |
1398 |
return it.previous(); |
1399 |
else |
1400 |
throw new NoSuchElementException(); |
1401 |
} |
1402 |
|
1403 |
public int nextIndex() { |
1404 |
return it.nextIndex() - offset; |
1405 |
} |
1406 |
|
1407 |
public int previousIndex() { |
1408 |
return it.previousIndex() - offset; |
1409 |
} |
1410 |
|
1411 |
public void remove() { |
1412 |
throw new UnsupportedOperationException(); |
1413 |
} |
1414 |
|
1415 |
public void set(E e) { |
1416 |
throw new UnsupportedOperationException(); |
1417 |
} |
1418 |
|
1419 |
public void add(E e) { |
1420 |
throw new UnsupportedOperationException(); |
1421 |
} |
1422 |
|
1423 |
@Override |
1424 |
@SuppressWarnings("unchecked") |
1425 |
public void forEachRemaining(Consumer<? super E> action) { |
1426 |
Objects.requireNonNull(action); |
1427 |
while (nextIndex() < size) { |
1428 |
action.accept(it.next()); |
1429 |
} |
1430 |
} |
1431 |
} |
1432 |
|
1433 |
/** Initializes the lock; for use when deserializing or cloning. */ |
1434 |
private void resetLock() { |
1435 |
Field lockField = java.security.AccessController.doPrivileged( |
1436 |
(java.security.PrivilegedAction<Field>) () -> { |
1437 |
try { |
1438 |
Field f = CopyOnWriteArrayList.class |
1439 |
.getDeclaredField("lock"); |
1440 |
f.setAccessible(true); |
1441 |
return f; |
1442 |
} catch (ReflectiveOperationException e) { |
1443 |
throw new Error(e); |
1444 |
}}); |
1445 |
try { |
1446 |
lockField.set(this, new Object()); |
1447 |
} catch (IllegalAccessException e) { |
1448 |
throw new Error(e); |
1449 |
} |
1450 |
} |
1451 |
} |