1 |
/* |
2 |
* Written by Doug Lea with assistance from members of JCP JSR-166 |
3 |
* Expert Group and released to the public domain, as explained at |
4 |
* http://creativecommons.org/publicdomain/zero/1.0/ |
5 |
* Other contributors include Andrew Wright, Jeffrey Hayes, |
6 |
* Pat Fisher, Mike Judd. |
7 |
*/ |
8 |
|
9 |
import java.util.Arrays; |
10 |
import java.util.Collection; |
11 |
import java.util.Comparator; |
12 |
import java.util.Iterator; |
13 |
import java.util.NoSuchElementException; |
14 |
import java.util.PriorityQueue; |
15 |
import java.util.Queue; |
16 |
|
17 |
import junit.framework.Test; |
18 |
|
19 |
public class PriorityQueueTest extends JSR166TestCase { |
20 |
public static void main(String[] args) { |
21 |
main(suite(), args); |
22 |
} |
23 |
public static Test suite() { |
24 |
class Implementation implements CollectionImplementation { |
25 |
public Class<?> klazz() { return PriorityQueue.class; } |
26 |
public Collection emptyCollection() { return new PriorityQueue(); } |
27 |
public Object makeElement(int i) { return JSR166TestCase.itemFor(i); } |
28 |
public boolean isConcurrent() { return false; } |
29 |
public boolean permitsNulls() { return false; } |
30 |
} |
31 |
class ComparatorImplementation implements CollectionImplementation { |
32 |
public Class<?> klazz() { return PriorityQueue.class; } |
33 |
@SuppressWarnings("unchecked") |
34 |
public Collection emptyCollection() { |
35 |
return new PriorityQueue(new MyReverseComparator()); |
36 |
} |
37 |
public Object makeElement(int i) { return JSR166TestCase.itemFor(i); } |
38 |
public boolean isConcurrent() { return false; } |
39 |
public boolean permitsNulls() { return false; } |
40 |
} |
41 |
return newTestSuite( |
42 |
PriorityQueueTest.class, |
43 |
CollectionTest.testSuite(new Implementation()), |
44 |
CollectionTest.testSuite(new ComparatorImplementation())); |
45 |
} |
46 |
|
47 |
static class MyReverseComparator implements Comparator, java.io.Serializable { |
48 |
@SuppressWarnings("unchecked") |
49 |
public int compare(Object x, Object y) { |
50 |
return ((Comparable)y).compareTo(x); |
51 |
} |
52 |
} |
53 |
|
54 |
/** |
55 |
* Returns a new queue of given size containing consecutive |
56 |
* Items 0 ... n - 1. |
57 |
*/ |
58 |
private static PriorityQueue<Item> populatedQueue(int n) { |
59 |
PriorityQueue<Item> q = new PriorityQueue<>(n); |
60 |
assertTrue(q.isEmpty()); |
61 |
for (int i = n - 1; i >= 0; i -= 2) |
62 |
mustOffer(q, i); |
63 |
for (int i = (n & 1); i < n; i += 2) |
64 |
mustOffer(q, i); |
65 |
assertFalse(q.isEmpty()); |
66 |
mustEqual(n, q.size()); |
67 |
mustEqual(0, q.peek()); |
68 |
return q; |
69 |
} |
70 |
|
71 |
/** |
72 |
* A new queue has unbounded capacity |
73 |
*/ |
74 |
public void testConstructor1() { |
75 |
mustEqual(0, new PriorityQueue<Item>(SIZE).size()); |
76 |
} |
77 |
|
78 |
/** |
79 |
* Constructor throws IllegalArgumentException if capacity argument nonpositive |
80 |
*/ |
81 |
public void testConstructor2() { |
82 |
try { |
83 |
new PriorityQueue<Item>(0); |
84 |
shouldThrow(); |
85 |
} catch (IllegalArgumentException success) {} |
86 |
} |
87 |
|
88 |
/** |
89 |
* Initializing from null Collection throws NPE |
90 |
*/ |
91 |
public void testConstructor3() { |
92 |
try { |
93 |
new PriorityQueue<Item>((Collection<Item>)null); |
94 |
shouldThrow(); |
95 |
} catch (NullPointerException success) {} |
96 |
} |
97 |
|
98 |
/** |
99 |
* Initializing from Collection of null elements throws NPE |
100 |
*/ |
101 |
public void testConstructor4() { |
102 |
try { |
103 |
new PriorityQueue<Item>(Arrays.asList(new Item[SIZE])); |
104 |
shouldThrow(); |
105 |
} catch (NullPointerException success) {} |
106 |
} |
107 |
|
108 |
/** |
109 |
* Initializing from Collection with some null elements throws NPE |
110 |
*/ |
111 |
public void testConstructor5() { |
112 |
Item[] items = new Item[2]; |
113 |
items[0] = zero; |
114 |
try { |
115 |
new PriorityQueue<Item>(Arrays.asList(items)); |
116 |
shouldThrow(); |
117 |
} catch (NullPointerException success) {} |
118 |
} |
119 |
|
120 |
/** |
121 |
* Queue contains all elements of collection used to initialize |
122 |
*/ |
123 |
public void testConstructor6() { |
124 |
Item[] items = defaultItems; |
125 |
PriorityQueue<Item> q = new PriorityQueue<>(Arrays.asList(items)); |
126 |
for (int i = 0; i < SIZE; ++i) |
127 |
mustEqual(items[i], q.poll()); |
128 |
} |
129 |
|
130 |
/** |
131 |
* The comparator used in constructor is used |
132 |
*/ |
133 |
public void testConstructor7() { |
134 |
MyReverseComparator cmp = new MyReverseComparator(); |
135 |
@SuppressWarnings("unchecked") |
136 |
PriorityQueue<Item> q = new PriorityQueue<>(SIZE, cmp); |
137 |
assertEquals(cmp, q.comparator()); |
138 |
Item[] items = seqItems(SIZE); |
139 |
q.addAll(Arrays.asList(items)); |
140 |
for (int i = SIZE - 1; i >= 0; --i) |
141 |
mustEqual(items[i], q.poll()); |
142 |
} |
143 |
|
144 |
/** |
145 |
* isEmpty is true before add, false after |
146 |
*/ |
147 |
public void testEmpty() { |
148 |
PriorityQueue<Item> q = new PriorityQueue<>(2); |
149 |
assertTrue(q.isEmpty()); |
150 |
q.add(one); |
151 |
assertFalse(q.isEmpty()); |
152 |
q.add(two); |
153 |
q.remove(); |
154 |
q.remove(); |
155 |
assertTrue(q.isEmpty()); |
156 |
} |
157 |
|
158 |
/** |
159 |
* size changes when elements added and removed |
160 |
*/ |
161 |
public void testSize() { |
162 |
PriorityQueue<Item> q = populatedQueue(SIZE); |
163 |
for (int i = 0; i < SIZE; ++i) { |
164 |
mustEqual(SIZE - i, q.size()); |
165 |
q.remove(); |
166 |
} |
167 |
for (int i = 0; i < SIZE; ++i) { |
168 |
mustEqual(i, q.size()); |
169 |
mustAdd(q, i); |
170 |
} |
171 |
} |
172 |
|
173 |
/** |
174 |
* offer(null) throws NPE |
175 |
*/ |
176 |
public void testOfferNull() { |
177 |
PriorityQueue<Item> q = new PriorityQueue<>(1); |
178 |
try { |
179 |
q.offer(null); |
180 |
shouldThrow(); |
181 |
} catch (NullPointerException success) {} |
182 |
} |
183 |
|
184 |
/** |
185 |
* add(null) throws NPE |
186 |
*/ |
187 |
public void testAddNull() { |
188 |
PriorityQueue<Item> q = new PriorityQueue<>(1); |
189 |
try { |
190 |
q.add(null); |
191 |
shouldThrow(); |
192 |
} catch (NullPointerException success) {} |
193 |
} |
194 |
|
195 |
/** |
196 |
* Offer of comparable element succeeds |
197 |
*/ |
198 |
public void testOffer() { |
199 |
PriorityQueue<Item> q = new PriorityQueue<>(1); |
200 |
assertTrue(q.offer(zero)); |
201 |
assertTrue(q.offer(one)); |
202 |
} |
203 |
|
204 |
/** |
205 |
* Offer of non-Comparable throws CCE |
206 |
*/ |
207 |
public void testOfferNonComparable() { |
208 |
PriorityQueue<Object> q = new PriorityQueue<>(1); |
209 |
try { |
210 |
q.offer(new Object()); |
211 |
shouldThrow(); |
212 |
} catch (ClassCastException success) { |
213 |
assertTrue(q.isEmpty()); |
214 |
mustEqual(0, q.size()); |
215 |
assertNull(q.poll()); |
216 |
} |
217 |
} |
218 |
|
219 |
/** |
220 |
* add of comparable succeeds |
221 |
*/ |
222 |
public void testAdd() { |
223 |
PriorityQueue<Item> q = new PriorityQueue<>(SIZE); |
224 |
for (int i = 0; i < SIZE; ++i) { |
225 |
mustEqual(i, q.size()); |
226 |
mustAdd(q, i); |
227 |
} |
228 |
} |
229 |
|
230 |
/** |
231 |
* addAll(null) throws NPE |
232 |
*/ |
233 |
public void testAddAll1() { |
234 |
PriorityQueue<Item> q = new PriorityQueue<>(1); |
235 |
try { |
236 |
q.addAll(null); |
237 |
shouldThrow(); |
238 |
} catch (NullPointerException success) {} |
239 |
} |
240 |
|
241 |
/** |
242 |
* addAll of a collection with null elements throws NPE |
243 |
*/ |
244 |
public void testAddAll2() { |
245 |
PriorityQueue<Item> q = new PriorityQueue<>(SIZE); |
246 |
try { |
247 |
q.addAll(Arrays.asList(new Item[SIZE])); |
248 |
shouldThrow(); |
249 |
} catch (NullPointerException success) {} |
250 |
} |
251 |
|
252 |
/** |
253 |
* addAll of a collection with any null elements throws NPE after |
254 |
* possibly adding some elements |
255 |
*/ |
256 |
public void testAddAll3() { |
257 |
PriorityQueue<Item> q = new PriorityQueue<>(SIZE); |
258 |
Item[] items = new Item[2]; |
259 |
items[0] = zero; |
260 |
try { |
261 |
q.addAll(Arrays.asList(items)); |
262 |
shouldThrow(); |
263 |
} catch (NullPointerException success) {} |
264 |
} |
265 |
|
266 |
/** |
267 |
* Queue contains all elements of successful addAll |
268 |
*/ |
269 |
public void testAddAll5() { |
270 |
Item[] empty = new Item[0]; |
271 |
Item[] items = new Item[SIZE]; |
272 |
for (int i = 0; i < SIZE; ++i) |
273 |
items[i] = itemFor(SIZE - 1 - i); |
274 |
PriorityQueue<Item> q = new PriorityQueue<>(SIZE); |
275 |
assertFalse(q.addAll(Arrays.asList(empty))); |
276 |
assertTrue(q.addAll(Arrays.asList(items))); |
277 |
for (int i = 0; i < SIZE; ++i) |
278 |
mustEqual(i, q.poll()); |
279 |
} |
280 |
|
281 |
/** |
282 |
* poll succeeds unless empty |
283 |
*/ |
284 |
public void testPoll() { |
285 |
PriorityQueue<Item> q = populatedQueue(SIZE); |
286 |
for (int i = 0; i < SIZE; ++i) { |
287 |
mustEqual(i, q.poll()); |
288 |
} |
289 |
assertNull(q.poll()); |
290 |
} |
291 |
|
292 |
/** |
293 |
* peek returns next element, or null if empty |
294 |
*/ |
295 |
public void testPeek() { |
296 |
PriorityQueue<Item> q = populatedQueue(SIZE); |
297 |
for (int i = 0; i < SIZE; ++i) { |
298 |
mustEqual(i, q.peek()); |
299 |
mustEqual(i, q.poll()); |
300 |
assertTrue(q.peek() == null || |
301 |
!q.peek().equals(i)); |
302 |
} |
303 |
assertNull(q.peek()); |
304 |
} |
305 |
|
306 |
/** |
307 |
* element returns next element, or throws NSEE if empty |
308 |
*/ |
309 |
public void testElement() { |
310 |
PriorityQueue<Item> q = populatedQueue(SIZE); |
311 |
for (int i = 0; i < SIZE; ++i) { |
312 |
mustEqual(i, q.element()); |
313 |
mustEqual(i, q.poll()); |
314 |
} |
315 |
try { |
316 |
q.element(); |
317 |
shouldThrow(); |
318 |
} catch (NoSuchElementException success) {} |
319 |
} |
320 |
|
321 |
/** |
322 |
* remove removes next element, or throws NSEE if empty |
323 |
*/ |
324 |
public void testRemove() { |
325 |
PriorityQueue<Item> q = populatedQueue(SIZE); |
326 |
for (int i = 0; i < SIZE; ++i) { |
327 |
mustEqual(i, q.remove()); |
328 |
} |
329 |
try { |
330 |
q.remove(); |
331 |
shouldThrow(); |
332 |
} catch (NoSuchElementException success) {} |
333 |
} |
334 |
|
335 |
/** |
336 |
* remove(x) removes x and returns true if present |
337 |
*/ |
338 |
public void testRemoveElement() { |
339 |
PriorityQueue<Item> q = populatedQueue(SIZE); |
340 |
for (int i = 1; i < SIZE; i += 2) { |
341 |
mustContain(q, i); |
342 |
mustRemove(q, i); |
343 |
mustNotContain(q, i); |
344 |
mustContain(q, i - 1); |
345 |
} |
346 |
for (int i = 0; i < SIZE; i += 2) { |
347 |
mustContain(q, i); |
348 |
mustRemove(q, i); |
349 |
mustNotContain(q, i); |
350 |
mustNotRemove(q, i + 1); |
351 |
mustNotContain(q, i + 1); |
352 |
} |
353 |
assertTrue(q.isEmpty()); |
354 |
} |
355 |
|
356 |
/** |
357 |
* contains(x) reports true when elements added but not yet removed |
358 |
*/ |
359 |
public void testContains() { |
360 |
PriorityQueue<Item> q = populatedQueue(SIZE); |
361 |
for (int i = 0; i < SIZE; ++i) { |
362 |
mustContain(q, i); |
363 |
q.poll(); |
364 |
mustNotContain(q, i); |
365 |
} |
366 |
} |
367 |
|
368 |
/** |
369 |
* clear removes all elements |
370 |
*/ |
371 |
public void testClear() { |
372 |
PriorityQueue<Item> q = populatedQueue(SIZE); |
373 |
q.clear(); |
374 |
assertTrue(q.isEmpty()); |
375 |
mustEqual(0, q.size()); |
376 |
q.add(one); |
377 |
assertFalse(q.isEmpty()); |
378 |
q.clear(); |
379 |
assertTrue(q.isEmpty()); |
380 |
} |
381 |
|
382 |
/** |
383 |
* containsAll(c) is true when c contains a subset of elements |
384 |
*/ |
385 |
public void testContainsAll() { |
386 |
PriorityQueue<Item> q = populatedQueue(SIZE); |
387 |
PriorityQueue<Item> p = new PriorityQueue<>(SIZE); |
388 |
for (int i = 0; i < SIZE; ++i) { |
389 |
assertTrue(q.containsAll(p)); |
390 |
assertFalse(p.containsAll(q)); |
391 |
mustAdd(p, i); |
392 |
} |
393 |
assertTrue(p.containsAll(q)); |
394 |
} |
395 |
|
396 |
/** |
397 |
* retainAll(c) retains only those elements of c and reports true if changed |
398 |
*/ |
399 |
public void testRetainAll() { |
400 |
PriorityQueue<Item> q = populatedQueue(SIZE); |
401 |
PriorityQueue<Item> p = populatedQueue(SIZE); |
402 |
for (int i = 0; i < SIZE; ++i) { |
403 |
boolean changed = q.retainAll(p); |
404 |
if (i == 0) |
405 |
assertFalse(changed); |
406 |
else |
407 |
assertTrue(changed); |
408 |
|
409 |
assertTrue(q.containsAll(p)); |
410 |
mustEqual(SIZE - i, q.size()); |
411 |
p.remove(); |
412 |
} |
413 |
} |
414 |
|
415 |
/** |
416 |
* removeAll(c) removes only those elements of c and reports true if changed |
417 |
*/ |
418 |
public void testRemoveAll() { |
419 |
for (int i = 1; i < SIZE; ++i) { |
420 |
PriorityQueue<Item> q = populatedQueue(SIZE); |
421 |
PriorityQueue<Item> p = populatedQueue(i); |
422 |
assertTrue(q.removeAll(p)); |
423 |
mustEqual(SIZE - i, q.size()); |
424 |
for (int j = 0; j < i; ++j) { |
425 |
mustNotContain(q, p.remove()); |
426 |
} |
427 |
} |
428 |
} |
429 |
|
430 |
/** |
431 |
* toArray contains all elements |
432 |
*/ |
433 |
public void testToArray() { |
434 |
PriorityQueue<Item> q = populatedQueue(SIZE); |
435 |
Object[] a = q.toArray(); |
436 |
assertSame(Object[].class, a.getClass()); |
437 |
Arrays.sort(a); |
438 |
for (Object o : a) |
439 |
assertSame(o, q.poll()); |
440 |
assertTrue(q.isEmpty()); |
441 |
} |
442 |
|
443 |
/** |
444 |
* toArray(a) contains all elements |
445 |
*/ |
446 |
public void testToArray2() { |
447 |
PriorityQueue<Item> q = populatedQueue(SIZE); |
448 |
Item[] items = new Item[SIZE]; |
449 |
Item[] array = q.toArray(items); |
450 |
assertSame(items, array); |
451 |
Arrays.sort(items); |
452 |
for (Item o : items) |
453 |
assertSame(o, q.poll()); |
454 |
assertTrue(q.isEmpty()); |
455 |
} |
456 |
|
457 |
/** |
458 |
* iterator iterates through all elements |
459 |
*/ |
460 |
public void testIterator() { |
461 |
PriorityQueue<Item> q = populatedQueue(SIZE); |
462 |
Iterator<? extends Item> it = q.iterator(); |
463 |
int i; |
464 |
for (i = 0; it.hasNext(); i++) |
465 |
mustContain(q, it.next()); |
466 |
mustEqual(i, SIZE); |
467 |
assertIteratorExhausted(it); |
468 |
} |
469 |
|
470 |
/** |
471 |
* iterator of empty collection has no elements |
472 |
*/ |
473 |
public void testEmptyIterator() { |
474 |
assertIteratorExhausted(new PriorityQueue<Item>().iterator()); |
475 |
} |
476 |
|
477 |
/** |
478 |
* iterator.remove removes current element |
479 |
*/ |
480 |
public void testIteratorRemove() { |
481 |
final PriorityQueue<Item> q = new PriorityQueue<>(3); |
482 |
q.add(two); |
483 |
q.add(one); |
484 |
q.add(three); |
485 |
|
486 |
Iterator<? extends Item> it = q.iterator(); |
487 |
it.next(); |
488 |
it.remove(); |
489 |
|
490 |
it = q.iterator(); |
491 |
mustEqual(it.next(), two); |
492 |
mustEqual(it.next(), three); |
493 |
assertFalse(it.hasNext()); |
494 |
} |
495 |
|
496 |
/** |
497 |
* toString contains toStrings of elements |
498 |
*/ |
499 |
public void testToString() { |
500 |
PriorityQueue<Item> q = populatedQueue(SIZE); |
501 |
String s = q.toString(); |
502 |
for (int i = 0; i < SIZE; ++i) { |
503 |
assertTrue(s.contains(String.valueOf(i))); |
504 |
} |
505 |
} |
506 |
|
507 |
/** |
508 |
* A deserialized/reserialized queue has same elements |
509 |
*/ |
510 |
public void testSerialization() throws Exception { |
511 |
Queue<Item> x = populatedQueue(SIZE); |
512 |
Queue<Item> y = serialClone(x); |
513 |
|
514 |
assertNotSame(x, y); |
515 |
mustEqual(x.size(), y.size()); |
516 |
while (!x.isEmpty()) { |
517 |
assertFalse(y.isEmpty()); |
518 |
mustEqual(x.remove(), y.remove()); |
519 |
} |
520 |
assertTrue(y.isEmpty()); |
521 |
} |
522 |
} |