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1 : tim 1.2 package java.util;
2 : tim 1.1
3 :     /**
4 : dholmes 1.23 * An unbounded priority {@linkplain Queue queue} based on a priority heap.
5 :     * This queue orders
6 : brian 1.6 * elements according to an order specified at construction time, which is
7 : tim 1.19 * specified in the same manner as {@link java.util.TreeSet} and
8 : dholmes 1.18 * {@link java.util.TreeMap}: elements are ordered
9 : tim 1.2 * either according to their <i>natural order</i> (see {@link Comparable}), or
10 : tim 1.19 * according to a {@link java.util.Comparator}, depending on which
11 : dholmes 1.18 * constructor is used.
12 : tim 1.19 * <p>The <em>head</em> of this queue is the <em>least</em> element with
13 :     * respect to the specified ordering.
14 : dholmes 1.18 * If multiple elements are tied for least value, the
15 : tim 1.14 * head is one of those elements. A priority queue does not permit
16 : dholmes 1.11 * <tt>null</tt> elements.
17 : tim 1.14 *
18 : dholmes 1.11 * <p>The {@link #remove()} and {@link #poll()} methods remove and
19 :     * return the head of the queue.
20 :     *
21 :     * <p>The {@link #element()} and {@link #peek()} methods return, but do
22 :     * not delete, the head of the queue.
23 : tim 1.2 *
24 : dl 1.7 * <p>A priority queue has a <i>capacity</i>. The capacity is the
25 :     * size of the array used internally to store the elements on the
26 : dholmes 1.20 * queue.
27 : dholmes 1.18 * It is always at least as large as the queue size. As
28 : dl 1.7 * elements are added to a priority queue, its capacity grows
29 :     * automatically. The details of the growth policy are not specified.
30 : tim 1.2 *
31 : dholmes 1.11 * <p>Implementation note: this implementation provides O(log(n)) time
32 :     * for the insertion methods (<tt>offer</tt>, <tt>poll</tt>,
33 :     * <tt>remove()</tt> and <tt>add</tt>) methods; linear time for the
34 :     * <tt>remove(Object)</tt> and <tt>contains(Object)</tt> methods; and
35 :     * constant time for the retrieval methods (<tt>peek</tt>,
36 :     * <tt>element</tt>, and <tt>size</tt>).
37 : tim 1.2 *
38 :     * <p>This class is a member of the
39 :     * <a href="{@docRoot}/../guide/collections/index.html">
40 :     * Java Collections Framework</a>.
41 : dl 1.7 * @since 1.5
42 :     * @author Josh Bloch
43 : tim 1.2 */
44 :     public class PriorityQueue<E> extends AbstractQueue<E>
45 : dl 1.22 implements Queue<E>, java.io.Serializable {
46 : dholmes 1.11
47 : tim 1.2 private static final int DEFAULT_INITIAL_CAPACITY = 11;
48 : tim 1.1
49 : tim 1.2 /**
50 :     * Priority queue represented as a balanced binary heap: the two children
51 :     * of queue[n] are queue[2*n] and queue[2*n + 1]. The priority queue is
52 :     * ordered by comparator, or by the elements' natural ordering, if
53 : brian 1.6 * comparator is null: For each node n in the heap and each descendant d
54 :     * of n, n <= d.
55 : tim 1.2 *
56 : brian 1.6 * The element with the lowest value is in queue[1], assuming the queue is
57 :     * nonempty. (A one-based array is used in preference to the traditional
58 :     * zero-based array to simplify parent and child calculations.)
59 : tim 1.2 *
60 :     * queue.length must be >= 2, even if size == 0.
61 :     */
62 : tim 1.16 private transient Object[] queue;
63 : tim 1.1
64 : tim 1.2 /**
65 :     * The number of elements in the priority queue.
66 :     */
67 :     private int size = 0;
68 : tim 1.1
69 : tim 1.2 /**
70 :     * The comparator, or null if priority queue uses elements'
71 :     * natural ordering.
72 :     */
73 : tim 1.16 private final Comparator<? super E> comparator;
74 : tim 1.2
75 :     /**
76 :     * The number of times this priority queue has been
77 :     * <i>structurally modified</i>. See AbstractList for gory details.
78 :     */
79 : dl 1.5 private transient int modCount = 0;
80 : tim 1.2
81 :     /**
82 : dholmes 1.21 * Creates a <tt>PriorityQueue</tt> with the default initial capacity
83 : dl 1.7 * (11) that orders its elements according to their natural
84 : tim 1.24 * ordering (using <tt>Comparable</tt>).
85 : tim 1.2 */
86 :     public PriorityQueue() {
87 : dholmes 1.11 this(DEFAULT_INITIAL_CAPACITY, null);
88 : tim 1.1 }
89 : tim 1.2
90 :     /**
91 : dholmes 1.21 * Creates a <tt>PriorityQueue</tt> with the specified initial capacity
92 : dl 1.7 * that orders its elements according to their natural ordering
93 : tim 1.24 * (using <tt>Comparable</tt>).
94 : tim 1.2 *
95 :     * @param initialCapacity the initial capacity for this priority queue.
96 : dholmes 1.23 * @throws IllegalArgumentException if <tt>initialCapacity</tt> is less
97 :     * than 1
98 : tim 1.2 */
99 :     public PriorityQueue(int initialCapacity) {
100 :     this(initialCapacity, null);
101 : tim 1.1 }
102 : tim 1.2
103 :     /**
104 : dholmes 1.21 * Creates a <tt>PriorityQueue</tt> with the specified initial capacity
105 : tim 1.2 * that orders its elements according to the specified comparator.
106 :     *
107 :     * @param initialCapacity the initial capacity for this priority queue.
108 :     * @param comparator the comparator used to order this priority queue.
109 : dholmes 1.11 * If <tt>null</tt> then the order depends on the elements' natural
110 :     * ordering.
111 : dholmes 1.15 * @throws IllegalArgumentException if <tt>initialCapacity</tt> is less
112 :     * than 1
113 : tim 1.2 */
114 : dholmes 1.23 public PriorityQueue(int initialCapacity,
115 :     Comparator<? super E> comparator) {
116 : tim 1.2 if (initialCapacity < 1)
117 : dholmes 1.15 throw new IllegalArgumentException();
118 : tim 1.16 this.queue = new Object[initialCapacity + 1];
119 : tim 1.2 this.comparator = comparator;
120 : tim 1.1 }
121 :    
122 : tim 1.2 /**
123 : dl 1.22 * Common code to initialize underlying queue array across
124 :     * constructors below.
125 :     */
126 :     private void initializeArray(Collection<? extends E> c) {
127 :     int sz = c.size();
128 :     int initialCapacity = (int)Math.min((sz * 110L) / 100,
129 :     Integer.MAX_VALUE - 1);
130 :     if (initialCapacity < 1)
131 :     initialCapacity = 1;
132 :    
133 :     this.queue = new Object[initialCapacity + 1];
134 :     }
135 :    
136 :     /**
137 :     * Initially fill elements of the queue array under the
138 :     * knowledge that it is sorted or is another PQ, in which
139 :     * case we can just place the elements without fixups.
140 :     */
141 :     private void fillFromSorted(Collection<? extends E> c) {
142 :     for (Iterator<? extends E> i = c.iterator(); i.hasNext(); )
143 :     queue[++size] = i.next();
144 :     }
145 :    
146 :    
147 :     /**
148 :     * Initially fill elements of the queue array that is
149 :     * not to our knowledge sorted, so we must add them
150 :     * one by one.
151 :     */
152 :     private void fillFromUnsorted(Collection<? extends E> c) {
153 :     for (Iterator<? extends E> i = c.iterator(); i.hasNext(); )
154 :     add(i.next());
155 :     }
156 :    
157 :     /**
158 :     * Creates a <tt>PriorityQueue</tt> containing the elements in the
159 :     * specified collection. The priority queue has an initial
160 :     * capacity of 110% of the size of the specified collection or 1
161 :     * if the collection is empty. If the specified collection is an
162 : tim 1.25 * instance of a {@link java.util.SortedSet} or is another
163 : dl 1.22 * <tt>PriorityQueue</tt>, the priority queue will be sorted
164 :     * according to the same comparator, or according to its elements'
165 :     * natural order if the collection is sorted according to its
166 :     * elements' natural order. Otherwise, the priority queue is
167 :     * ordered according to its elements' natural order.
168 : tim 1.2 *
169 : dholmes 1.15 * @param c the collection whose elements are to be placed
170 : tim 1.2 * into this priority queue.
171 :     * @throws ClassCastException if elements of the specified collection
172 :     * cannot be compared to one another according to the priority
173 :     * queue's ordering.
174 : dholmes 1.15 * @throws NullPointerException if <tt>c</tt> or any element within it
175 :     * is <tt>null</tt>
176 : tim 1.2 */
177 : tim 1.16 public PriorityQueue(Collection<? extends E> c) {
178 : dl 1.22 initializeArray(c);
179 : dl 1.27 if (c instanceof SortedSet) {
180 : dl 1.28 // @fixme double-cast workaround for compiler
181 :     SortedSet<? extends E> s = (SortedSet<? extends E>) (SortedSet)c;
182 : dl 1.22 comparator = (Comparator<? super E>)s.comparator();
183 :     fillFromSorted(s);
184 : dl 1.27 } else if (c instanceof PriorityQueue) {
185 : dl 1.22 PriorityQueue<? extends E> s = (PriorityQueue<? extends E>) c;
186 :     comparator = (Comparator<? super E>)s.comparator();
187 :     fillFromSorted(s);
188 : tim 1.26 } else {
189 : tim 1.2 comparator = null;
190 : dl 1.22 fillFromUnsorted(c);
191 : tim 1.2 }
192 : dl 1.22 }
193 :    
194 :     /**
195 :     * Creates a <tt>PriorityQueue</tt> containing the elements in the
196 :     * specified collection. The priority queue has an initial
197 :     * capacity of 110% of the size of the specified collection or 1
198 :     * if the collection is empty. This priority queue will be sorted
199 :     * according to the same comparator as the given collection, or
200 :     * according to its elements' natural order if the collection is
201 :     * sorted according to its elements' natural order.
202 :     *
203 :     * @param c the collection whose elements are to be placed
204 :     * into this priority queue.
205 :     * @throws ClassCastException if elements of the specified collection
206 :     * cannot be compared to one another according to the priority
207 :     * queue's ordering.
208 :     * @throws NullPointerException if <tt>c</tt> or any element within it
209 :     * is <tt>null</tt>
210 :     */
211 :     public PriorityQueue(PriorityQueue<? extends E> c) {
212 :     initializeArray(c);
213 :     comparator = (Comparator<? super E>)c.comparator();
214 :     fillFromSorted(c);
215 :     }
216 : dholmes 1.18
217 : dl 1.22 /**
218 :     * Creates a <tt>PriorityQueue</tt> containing the elements in the
219 :     * specified collection. The priority queue has an initial
220 :     * capacity of 110% of the size of the specified collection or 1
221 :     * if the collection is empty. This priority queue will be sorted
222 :     * according to the same comparator as the given collection, or
223 :     * according to its elements' natural order if the collection is
224 :     * sorted according to its elements' natural order.
225 :     *
226 :     * @param c the collection whose elements are to be placed
227 :     * into this priority queue.
228 :     * @throws ClassCastException if elements of the specified collection
229 :     * cannot be compared to one another according to the priority
230 :     * queue's ordering.
231 :     * @throws NullPointerException if <tt>c</tt> or any element within it
232 :     * is <tt>null</tt>
233 :     */
234 :     public PriorityQueue(SortedSet<? extends E> c) {
235 :     initializeArray(c);
236 :     comparator = (Comparator<? super E>)c.comparator();
237 :     fillFromSorted(c);
238 : tim 1.1 }
239 :    
240 : dl 1.22 /**
241 :     * Resize array, if necessary, to be able to hold given index
242 :     */
243 :     private void grow(int index) {
244 :     int newlen = queue.length;
245 :     if (index < newlen) // don't need to grow
246 :     return;
247 :     if (index == Integer.MAX_VALUE)
248 :     throw new OutOfMemoryError();
249 :     while (newlen <= index) {
250 :     if (newlen >= Integer.MAX_VALUE / 2) // avoid overflow
251 :     newlen = Integer.MAX_VALUE;
252 :     else
253 :     newlen <<= 2;
254 :     }
255 :     Object[] newQueue = new Object[newlen];
256 :     System.arraycopy(queue, 0, newQueue, 0, queue.length);
257 :     queue = newQueue;
258 :     }
259 :    
260 : tim 1.2 // Queue Methods
261 :    
262 : dholmes 1.23
263 :    
264 : tim 1.2 /**
265 : dholmes 1.11 * Add the specified element to this priority queue.
266 : tim 1.2 *
267 : dholmes 1.11 * @return <tt>true</tt>
268 :     * @throws ClassCastException if the specified element cannot be compared
269 :     * with elements currently in the priority queue according
270 :     * to the priority queue's ordering.
271 : dholmes 1.18 * @throws NullPointerException if the specified element is <tt>null</tt>.
272 : tim 1.2 */
273 : dholmes 1.18 public boolean offer(E o) {
274 :     if (o == null)
275 : dholmes 1.11 throw new NullPointerException();
276 :     modCount++;
277 :     ++size;
278 :    
279 :     // Grow backing store if necessary
280 : dl 1.22 if (size >= queue.length)
281 :     grow(size);
282 : dholmes 1.11
283 : dholmes 1.18 queue[size] = o;
284 : dholmes 1.11 fixUp(size);
285 :     return true;
286 :     }
287 :    
288 : tim 1.1 public E poll() {
289 : tim 1.2 if (size == 0)
290 :     return null;
291 : tim 1.16 return (E) remove(1);
292 : tim 1.1 }
293 : tim 1.2
294 : tim 1.1 public E peek() {
295 : tim 1.16 return (E) queue[1];
296 : tim 1.1 }
297 :    
298 : dholmes 1.23 // Collection Methods - the first two override to update docs
299 : dholmes 1.11
300 :     /**
301 : dholmes 1.23 * Adds the specified element to this queue.
302 :     * @return <tt>true</tt> (as per the general contract of
303 :     * <tt>Collection.add</tt>).
304 :     *
305 :     * @throws NullPointerException {@inheritDoc}
306 : dholmes 1.15 * @throws ClassCastException if the specified element cannot be compared
307 :     * with elements currently in the priority queue according
308 :     * to the priority queue's ordering.
309 : dholmes 1.11 */
310 : dholmes 1.18 public boolean add(E o) {
311 :     return super.add(o);
312 : dholmes 1.11 }
313 :    
314 : dholmes 1.23
315 : tim 1.14 /**
316 : dholmes 1.23 * Adds all of the elements in the specified collection to this queue.
317 :     * The behavior of this operation is undefined if
318 :     * the specified collection is modified while the operation is in
319 :     * progress. (This implies that the behavior of this call is undefined if
320 :     * the specified collection is this queue, and this queue is nonempty.)
321 :     * <p>
322 :     * This implementation iterates over the specified collection, and adds
323 :     * each object returned by the iterator to this collection, in turn.
324 :     * @throws NullPointerException {@inheritDoc}
325 : dholmes 1.15 * @throws ClassCastException if any element cannot be compared
326 :     * with elements currently in the priority queue according
327 :     * to the priority queue's ordering.
328 : tim 1.14 */
329 :     public boolean addAll(Collection<? extends E> c) {
330 :     return super.addAll(c);
331 :     }
332 : dholmes 1.11
333 : dholmes 1.23
334 :     /**
335 :     * Removes a single instance of the specified element from this
336 :     * queue, if it is present. More formally,
337 :     * removes an element <tt>e</tt> such that <tt>(o==null ? e==null :
338 :     * o.equals(e))</tt>, if the queue contains one or more such
339 :     * elements. Returns <tt>true</tt> if the queue contained the
340 :     * specified element (or equivalently, if the queue changed as a
341 :     * result of the call).
342 :     *
343 :     * <p>This implementation iterates over the queue looking for the
344 :     * specified element. If it finds the element, it removes the element
345 :     * from the queue using the iterator's remove method.<p>
346 :     *
347 :     */
348 : dl 1.12 public boolean remove(Object o) {
349 : dholmes 1.11 if (o == null)
350 : dholmes 1.15 return false;
351 : tim 1.2
352 :     if (comparator == null) {
353 :     for (int i = 1; i <= size; i++) {
354 : tim 1.16 if (((Comparable<E>)queue[i]).compareTo((E)o) == 0) {
355 : tim 1.2 remove(i);
356 :     return true;
357 :     }
358 :     }
359 :     } else {
360 :     for (int i = 1; i <= size; i++) {
361 : tim 1.16 if (comparator.compare((E)queue[i], (E)o) == 0) {
362 : tim 1.2 remove(i);
363 :     return true;
364 :     }
365 :     }
366 :     }
367 : tim 1.1 return false;
368 :     }
369 : tim 1.2
370 : dholmes 1.23 /**
371 :     * Returns an iterator over the elements in this queue. The iterator
372 :     * does not return the elements in any particular order.
373 :     *
374 :     * @return an iterator over the elements in this queue.
375 :     */
376 : tim 1.2 public Iterator<E> iterator() {
377 : dl 1.7 return new Itr();
378 : tim 1.2 }
379 :    
380 :     private class Itr implements Iterator<E> {
381 : dl 1.7 /**
382 :     * Index (into queue array) of element to be returned by
383 : tim 1.2 * subsequent call to next.
384 : dl 1.7 */
385 :     private int cursor = 1;
386 : tim 1.2
387 : dl 1.7 /**
388 :     * Index of element returned by most recent call to next or
389 :     * previous. Reset to 0 if this element is deleted by a call
390 :     * to remove.
391 :     */
392 :     private int lastRet = 0;
393 :    
394 :     /**
395 :     * The modCount value that the iterator believes that the backing
396 :     * List should have. If this expectation is violated, the iterator
397 :     * has detected concurrent modification.
398 :     */
399 :     private int expectedModCount = modCount;
400 : tim 1.2
401 : dl 1.7 public boolean hasNext() {
402 :     return cursor <= size;
403 :     }
404 :    
405 :     public E next() {
406 : tim 1.2 checkForComodification();
407 :     if (cursor > size)
408 : dl 1.7 throw new NoSuchElementException();
409 : tim 1.16 E result = (E) queue[cursor];
410 : tim 1.2 lastRet = cursor++;
411 :     return result;
412 : dl 1.7 }
413 : tim 1.2
414 : dl 1.7 public void remove() {
415 :     if (lastRet == 0)
416 :     throw new IllegalStateException();
417 : tim 1.2 checkForComodification();
418 :    
419 :     PriorityQueue.this.remove(lastRet);
420 :     if (lastRet < cursor)
421 :     cursor--;
422 :     lastRet = 0;
423 :     expectedModCount = modCount;
424 : dl 1.7 }
425 : tim 1.2
426 : dl 1.7 final void checkForComodification() {
427 :     if (modCount != expectedModCount)
428 :     throw new ConcurrentModificationException();
429 :     }
430 : tim 1.2 }
431 :    
432 : tim 1.1 public int size() {
433 : tim 1.2 return size;
434 : tim 1.1 }
435 : tim 1.2
436 :     /**
437 :     * Remove all elements from the priority queue.
438 :     */
439 :     public void clear() {
440 :     modCount++;
441 :    
442 :     // Null out element references to prevent memory leak
443 :     for (int i=1; i<=size; i++)
444 :     queue[i] = null;
445 :    
446 :     size = 0;
447 :     }
448 :    
449 :     /**
450 :     * Removes and returns the ith element from queue. Recall
451 :     * that queue is one-based, so 1 <= i <= size.
452 :     *
453 :     * XXX: Could further special-case i==size, but is it worth it?
454 :     * XXX: Could special-case i==0, but is it worth it?
455 :     */
456 :     private E remove(int i) {
457 :     assert i <= size;
458 :     modCount++;
459 :    
460 : tim 1.16 E result = (E) queue[i];
461 : tim 1.2 queue[i] = queue[size];
462 :     queue[size--] = null; // Drop extra ref to prevent memory leak
463 :     if (i <= size)
464 :     fixDown(i);
465 :     return result;
466 : tim 1.1 }
467 :    
468 : tim 1.2 /**
469 :     * Establishes the heap invariant (described above) assuming the heap
470 :     * satisfies the invariant except possibly for the leaf-node indexed by k
471 :     * (which may have a nextExecutionTime less than its parent's).
472 :     *
473 :     * This method functions by "promoting" queue[k] up the hierarchy
474 :     * (by swapping it with its parent) repeatedly until queue[k]
475 :     * is greater than or equal to its parent.
476 :     */
477 :     private void fixUp(int k) {
478 :     if (comparator == null) {
479 :     while (k > 1) {
480 :     int j = k >> 1;
481 : tim 1.16 if (((Comparable<E>)queue[j]).compareTo((E)queue[k]) <= 0)
482 : tim 1.2 break;
483 : tim 1.16 Object tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp;
484 : tim 1.2 k = j;
485 :     }
486 :     } else {
487 :     while (k > 1) {
488 :     int j = k >> 1;
489 : tim 1.16 if (comparator.compare((E)queue[j], (E)queue[k]) <= 0)
490 : tim 1.2 break;
491 : tim 1.16 Object tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp;
492 : tim 1.2 k = j;
493 :     }
494 :     }
495 :     }
496 :    
497 :     /**
498 :     * Establishes the heap invariant (described above) in the subtree
499 :     * rooted at k, which is assumed to satisfy the heap invariant except
500 :     * possibly for node k itself (which may be greater than its children).
501 :     *
502 :     * This method functions by "demoting" queue[k] down the hierarchy
503 :     * (by swapping it with its smaller child) repeatedly until queue[k]
504 :     * is less than or equal to its children.
505 :     */
506 :     private void fixDown(int k) {
507 :     int j;
508 :     if (comparator == null) {
509 :     while ((j = k << 1) <= size) {
510 : tim 1.16 if (j<size && ((Comparable<E>)queue[j]).compareTo((E)queue[j+1]) > 0)
511 : tim 1.2 j++; // j indexes smallest kid
512 : tim 1.16 if (((Comparable<E>)queue[k]).compareTo((E)queue[j]) <= 0)
513 : tim 1.2 break;
514 : tim 1.16 Object tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp;
515 : tim 1.2 k = j;
516 :     }
517 :     } else {
518 :     while ((j = k << 1) <= size) {
519 : tim 1.16 if (j < size && comparator.compare((E)queue[j], (E)queue[j+1]) > 0)
520 : tim 1.2 j++; // j indexes smallest kid
521 : tim 1.16 if (comparator.compare((E)queue[k], (E)queue[j]) <= 0)
522 : tim 1.2 break;
523 : tim 1.16 Object tmp = queue[j]; queue[j] = queue[k]; queue[k] = tmp;
524 : tim 1.2 k = j;
525 :     }
526 :     }
527 :     }
528 :    
529 : dholmes 1.23
530 :     /**
531 :     * Returns the comparator used to order this collection, or <tt>null</tt>
532 :     * if this collection is sorted according to its elements natural ordering
533 : tim 1.24 * (using <tt>Comparable</tt>).
534 : dholmes 1.23 *
535 :     * @return the comparator used to order this collection, or <tt>null</tt>
536 :     * if this collection is sorted according to its elements natural ordering.
537 :     */
538 : tim 1.16 public Comparator<? super E> comparator() {
539 : tim 1.2 return comparator;
540 :     }
541 : dl 1.5
542 :     /**
543 :     * Save the state of the instance to a stream (that
544 :     * is, serialize it).
545 :     *
546 :     * @serialData The length of the array backing the instance is
547 :     * emitted (int), followed by all of its elements (each an
548 :     * <tt>Object</tt>) in the proper order.
549 : dl 1.7 * @param s the stream
550 : dl 1.5 */
551 : dl 1.22 private void writeObject(java.io.ObjectOutputStream s)
552 : dl 1.5 throws java.io.IOException{
553 : dl 1.7 // Write out element count, and any hidden stuff
554 :     s.defaultWriteObject();
555 : dl 1.5
556 :     // Write out array length
557 :     s.writeInt(queue.length);
558 :    
559 : dl 1.7 // Write out all elements in the proper order.
560 :     for (int i=0; i<size; i++)
561 : dl 1.5 s.writeObject(queue[i]);
562 :     }
563 :    
564 :     /**
565 :     * Reconstitute the <tt>ArrayList</tt> instance from a stream (that is,
566 :     * deserialize it).
567 : dl 1.7 * @param s the stream
568 : dl 1.5 */
569 : dl 1.22 private void readObject(java.io.ObjectInputStream s)
570 : dl 1.5 throws java.io.IOException, ClassNotFoundException {
571 : dl 1.7 // Read in size, and any hidden stuff
572 :     s.defaultReadObject();
573 : dl 1.5
574 :     // Read in array length and allocate array
575 :     int arrayLength = s.readInt();
576 : tim 1.16 queue = new Object[arrayLength];
577 : dl 1.5
578 : dl 1.7 // Read in all elements in the proper order.
579 :     for (int i=0; i<size; i++)
580 : tim 1.16 queue[i] = s.readObject();
581 : dl 1.5 }
582 :    
583 : tim 1.1 }
584 : dholmes 1.11

Doug Lea
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