1 |
/* |
2 |
* Written by Josh Bloch of Google Inc. and released to the public domain, |
3 |
* as explained at http://creativecommons.org/publicdomain/zero/1.0/. |
4 |
*/ |
5 |
|
6 |
import java.io.*; |
7 |
import java.util.*; |
8 |
|
9 |
/** |
10 |
* Interface-based Deque tester. This test currently makes three |
11 |
* assumptions about the implementation under test: |
12 |
* |
13 |
* 1) It has no size limitation. |
14 |
* 2) It implements Serializable. |
15 |
* 3) It has a conventional (Collection) constructor. |
16 |
* |
17 |
* All of these assumptions could be relaxed. |
18 |
*/ |
19 |
public class DequeBash { |
20 |
static int seed = 7; |
21 |
static int nextTail = 0; |
22 |
static int nextHead = -1; |
23 |
static int size() { return nextTail - nextHead - 1; } |
24 |
|
25 |
static int random() { |
26 |
int r = seed; |
27 |
r ^= r << 13; // xorshift |
28 |
r ^= r >>> 17; |
29 |
return seed = r ^ (r << 5); |
30 |
} |
31 |
|
32 |
static int random(int bound) { |
33 |
return (random() & 0x7fffffff) % bound; |
34 |
} |
35 |
|
36 |
public static void main(String[] args) throws Exception { |
37 |
Class<?> cls = Class.forName(args[0]); |
38 |
long startTime = System.nanoTime(); |
39 |
for (int j = 0; j < 200; ++j) { |
40 |
@SuppressWarnings("unchecked") |
41 |
Deque<Integer> deque = (Deque<Integer>) cls.newInstance(); |
42 |
nextTail = 0; |
43 |
nextHead = -1; |
44 |
mainTest(deque, (random() & ((1 << 20) - 1))); |
45 |
if (deque.isEmpty()) System.out.print(" "); |
46 |
if ((j % 10) == 9) System.out.print("."); |
47 |
} |
48 |
long now = System.nanoTime(); |
49 |
long elapsedTimeMillis = (now - startTime) / (1000L * 1000L); |
50 |
System.out.printf("\ntotal time %d ms\n", elapsedTimeMillis); |
51 |
|
52 |
} |
53 |
|
54 |
static void mainTest(Deque<Integer> deque, int n) throws Exception { |
55 |
/* |
56 |
* Perform a random sequence of operations, keeping contiguous |
57 |
* sequence of integers on the deque. |
58 |
*/ |
59 |
for (int i = 0; i < n; i++) { |
60 |
sizeTests(deque); |
61 |
randomOp(deque); |
62 |
|
63 |
// Test iterator occasionally |
64 |
if ((i & 1023) == 0) { |
65 |
testIter(deque); |
66 |
testDescendingIter(deque); |
67 |
} |
68 |
|
69 |
// Test serialization and copying |
70 |
if ((i & 4095) == 0) { |
71 |
testEqual(deque, serialClone(deque)); |
72 |
testEqual(deque, copyConstructorClone(deque)); |
73 |
} |
74 |
|
75 |
// Test fancy removal stuff once in a blue moon |
76 |
if ((i & 8191) == 0) |
77 |
testRemove(deque); |
78 |
} |
79 |
|
80 |
// Stupid tests for clear, toString |
81 |
deque.clear(); |
82 |
testEmpty(deque); |
83 |
Collection<Integer> c = Arrays.asList(1, 2, 3); |
84 |
deque.addAll(c); |
85 |
if (!deque.toString().equals("[1, 2, 3]")) |
86 |
throw new Exception("Deque.toString(): " + deque.toString()); |
87 |
} |
88 |
|
89 |
static void testIter(Deque<Integer> deque) throws Exception { |
90 |
int next = nextHead + 1; |
91 |
int count = 0; |
92 |
for (int j : deque) { |
93 |
if (j != next++) |
94 |
throw new Exception("Element "+ j + " != " + (next-1)); |
95 |
count++; |
96 |
} |
97 |
if (count != size()) |
98 |
throw new Exception("Count " + count + " != " + size()); |
99 |
} |
100 |
|
101 |
static void testDescendingIter(Deque<Integer> deque) throws Exception { |
102 |
int next = deque.size() + nextHead; |
103 |
int count = 0; |
104 |
for (Iterator<Integer> it = deque.descendingIterator(); it.hasNext();) { |
105 |
int j = it.next(); |
106 |
if (j != next--) |
107 |
throw new Exception("Element "+ j + " != " + (next-1)); |
108 |
count++; |
109 |
} |
110 |
if (count != size()) |
111 |
throw new Exception("Count " + count + " != " + size()); |
112 |
} |
113 |
|
114 |
static void sizeTests(Deque<Integer> deque) throws Exception { |
115 |
if (deque.size() != size()) |
116 |
throw new Exception("Size: " + deque.size() + |
117 |
", expecting " + size()); |
118 |
if (deque.isEmpty() != (size() == 0)) |
119 |
throw new Exception( |
120 |
"IsEmpty " + deque.isEmpty() + ", size " + size()); |
121 |
// Check head and tail |
122 |
if (size() == 0) |
123 |
testEmpty(deque); |
124 |
else |
125 |
nonEmptyTest(deque); |
126 |
|
127 |
} |
128 |
|
129 |
static void nonEmptyTest(Deque<Integer> deque) throws Exception { |
130 |
if (deque.getFirst() != nextHead + 1) |
131 |
throw new Exception("getFirst got: " + |
132 |
deque.getFirst() + " expecting " + (nextHead + 1)); |
133 |
if (deque.element() != nextHead + 1) |
134 |
throw new Exception("element got: " + deque.element() + |
135 |
" expecting " + (nextHead + 1)); |
136 |
if (deque.peekFirst() != nextHead + 1) |
137 |
throw new Exception("peekFirst got: "+deque.peekFirst() + |
138 |
" expecting " + (nextHead + 1)); |
139 |
if (deque.peek() != nextHead + 1) |
140 |
throw new Exception("peek got: " + deque.peek() + |
141 |
" expecting " + (nextHead + 1)); |
142 |
|
143 |
if (deque.peekLast() != nextTail - 1) |
144 |
throw new Exception("peekLast got: " + deque.peekLast() + |
145 |
" expecting " + (nextTail - 1)); |
146 |
if (deque.getLast() != nextTail - 1) |
147 |
throw new Exception("getLast got: " + |
148 |
deque.getLast() + " expecting " + (nextTail - 1)); |
149 |
} |
150 |
|
151 |
static void randomOp(Deque<Integer> deque) throws Exception { |
152 |
|
153 |
// Perform a random operation |
154 |
switch (random() & 3) { |
155 |
case 0: |
156 |
switch (random() & 3) { |
157 |
case 0: deque.addLast(nextTail++); break; |
158 |
case 1: deque.offerLast(nextTail++); break; |
159 |
case 2: deque.offer(nextTail++); break; |
160 |
case 3: deque.add(nextTail++); break; |
161 |
default: throw new Exception("How'd we get here"); |
162 |
} |
163 |
break; |
164 |
case 1: |
165 |
if (size() == 0) { |
166 |
int result = 666; |
167 |
boolean threw = false; |
168 |
try { |
169 |
switch (random(3)) { |
170 |
case 0: result = deque.removeFirst(); break; |
171 |
case 1: result = deque.remove(); break; |
172 |
case 2: result = deque.pop(); break; |
173 |
default: throw new Exception("How'd we get here"); |
174 |
} |
175 |
} catch (NoSuchElementException e) { |
176 |
threw = true; |
177 |
} |
178 |
if (!threw) |
179 |
throw new Exception("Remove-no exception: " + result); |
180 |
} else { // deque nonempty |
181 |
int result = -1; |
182 |
switch (random(5)) { |
183 |
case 0: result = deque.removeFirst(); break; |
184 |
case 1: result = deque.remove(); break; |
185 |
case 2: result = deque.pop(); break; |
186 |
case 3: result = deque.pollFirst(); break; |
187 |
case 4: result = deque.poll(); break; |
188 |
default: throw new Exception("How'd we get here"); |
189 |
} |
190 |
if (result != ++nextHead) |
191 |
throw new Exception( |
192 |
"Removed "+ result + " expecting "+(nextHead - 1)); |
193 |
} |
194 |
break; |
195 |
case 2: |
196 |
switch (random(3)) { |
197 |
case 0: deque.addFirst(nextHead--); break; |
198 |
case 1: deque.offerFirst(nextHead--); break; |
199 |
case 2: deque.push(nextHead--); break; |
200 |
default: throw new Exception("How'd we get here"); |
201 |
} |
202 |
break; |
203 |
case 3: |
204 |
if (size() == 0) { |
205 |
int result = -1; |
206 |
boolean threw = false; |
207 |
try { |
208 |
result = deque.removeLast(); |
209 |
} catch (NoSuchElementException e) { |
210 |
threw = true; |
211 |
} |
212 |
if (!threw) |
213 |
throw new Exception("Remove-no exception: " + result); |
214 |
} else { // deque nonempty |
215 |
int result = ((random() & 1) == 0 ? |
216 |
deque.removeLast() : deque.pollLast()); |
217 |
if (result != --nextTail) |
218 |
throw new Exception( |
219 |
"Removed "+ result + " expecting "+(nextTail + 1)); |
220 |
} |
221 |
break; |
222 |
default: |
223 |
throw new Exception("How'd we get here"); |
224 |
} |
225 |
} |
226 |
|
227 |
private static void testEqual(Deque<Integer> d1, Deque<Integer> d2) |
228 |
throws Exception |
229 |
{ |
230 |
if (d1.size() != d2.size()) |
231 |
throw new Exception("Size " + d1.size() + " != " + d2.size()); |
232 |
Iterator<Integer> it = d2.iterator(); |
233 |
for (int i : d1) { |
234 |
int j = it.next(); |
235 |
if (j != i) |
236 |
throw new Exception("Element " + j + " != " + i); |
237 |
} |
238 |
|
239 |
for (int i : d1) |
240 |
if (!d2.contains(i)) |
241 |
throw new Exception("d2 doesn't contain " + i); |
242 |
for (int i : d2) |
243 |
if (!d1.contains(i)) |
244 |
throw new Exception("d2 doesn't contain " + i); |
245 |
|
246 |
if (d1.contains(Integer.MIN_VALUE)) |
247 |
throw new Exception("d2 contains Integer.MIN_VALUE"); |
248 |
if (d2.contains(Integer.MIN_VALUE)) |
249 |
throw new Exception("d2 contains Integer.MIN_VALUE"); |
250 |
if (d1.contains(null)) |
251 |
throw new Exception("d1 contains null"); |
252 |
if (d2.contains(null)) |
253 |
throw new Exception("d2 contains null"); |
254 |
|
255 |
if (!d1.containsAll(d2)) |
256 |
throw new Exception("d1 doesn't contain all of d2"); |
257 |
if (!d2.containsAll(d1)) |
258 |
throw new Exception("d2 doesn't contain all of d1"); |
259 |
Collection<Integer> c = Collections.singleton(Integer.MIN_VALUE); |
260 |
if (d1.containsAll(c)) |
261 |
throw new Exception("d1 contains all of {Integer.MIN_VALUE }"); |
262 |
if (d2.containsAll(c)) |
263 |
throw new Exception("d2 contains all of {Integer.MIN_VALUE }"); |
264 |
} |
265 |
|
266 |
@SuppressWarnings("unchecked") |
267 |
private static <T> T copyConstructorClone(T o) throws Exception { |
268 |
return (T) o.getClass().getConstructor(Collection.class).newInstance(o); |
269 |
} |
270 |
|
271 |
@SuppressWarnings("unchecked") |
272 |
private static <T> T serialClone(T o) throws Exception { |
273 |
ByteArrayOutputStream bos = new ByteArrayOutputStream(); |
274 |
ObjectOutputStream oos = new ObjectOutputStream(bos); |
275 |
oos.writeObject(o); |
276 |
oos.flush(); |
277 |
oos.close(); |
278 |
ByteArrayInputStream bin = |
279 |
new ByteArrayInputStream(bos.toByteArray()); |
280 |
ObjectInputStream ois = new ObjectInputStream(bin); |
281 |
return (T) ois.readObject(); |
282 |
} |
283 |
|
284 |
private static void testRemove(Deque<Integer> deque) throws Exception { |
285 |
Deque<Integer> copy = ((random() & 1) == 0) ? |
286 |
copyConstructorClone(deque) : |
287 |
serialClone(deque); |
288 |
|
289 |
int numRemoved = 0; |
290 |
for (Iterator<Integer> it = copy.iterator(); it.hasNext(); ) { |
291 |
if ((it.next() & 1) == 0) { |
292 |
it.remove(); |
293 |
numRemoved++; |
294 |
} |
295 |
} |
296 |
|
297 |
if (copy.size() + numRemoved != size()) |
298 |
throw new Exception((copy.size() + numRemoved) + " != " + size()); |
299 |
for (int i : copy) |
300 |
if ((i & 1) == 0) |
301 |
throw new Exception("Even number still present: " + i); |
302 |
|
303 |
List<Integer> elements = Arrays.asList(copy.toArray(new Integer[0])); |
304 |
Collections.shuffle(elements); |
305 |
for (int e : elements) { |
306 |
if (!copy.contains(e)) |
307 |
throw new Exception(e + " missing."); |
308 |
|
309 |
boolean removed = false; |
310 |
switch (random(3)) { |
311 |
case 0: removed = copy.remove(e); break; |
312 |
case 1: removed = copy.removeFirstOccurrence(e); break; |
313 |
case 2: removed = copy.removeLastOccurrence(e); break; |
314 |
default: throw new Exception("How'd we get here"); |
315 |
} |
316 |
if (!removed) |
317 |
throw new Exception(e + " not removed."); |
318 |
|
319 |
if (copy.contains(e)) |
320 |
throw new Exception(e + " present after removal."); |
321 |
} |
322 |
|
323 |
testEmpty(copy); |
324 |
|
325 |
copy = copyConstructorClone(deque); |
326 |
copy.retainAll(deque); |
327 |
testEqual(deque, copy); |
328 |
copy.removeAll(deque); |
329 |
testEmpty(copy); |
330 |
} |
331 |
|
332 |
static boolean checkedThrows; |
333 |
|
334 |
private static void testEmpty(Deque<Integer> deque) throws Exception { |
335 |
if (!deque.isEmpty()) |
336 |
throw new Exception("Deque isn't empty"); |
337 |
if (deque.size() != 0) |
338 |
throw new Exception("Deque size isn't zero"); |
339 |
if (!(deque.pollFirst() == null)) |
340 |
throw new Exception("pollFirst lies"); |
341 |
if (!(deque.poll() == null)) |
342 |
throw new Exception("poll lies"); |
343 |
if (!(deque.peekFirst() == null)) |
344 |
throw new Exception("peekFirst lies"); |
345 |
if (!(deque.peek() == null)) |
346 |
throw new Exception("peek lies"); |
347 |
if (!(deque.pollLast() == null)) |
348 |
throw new Exception("pollLast lies"); |
349 |
if (!(deque.peekLast() == null)) |
350 |
throw new Exception("peekLast lies"); |
351 |
|
352 |
if (!checkedThrows) { |
353 |
checkedThrows = true; |
354 |
boolean threw = false; |
355 |
int result = 666; |
356 |
try { |
357 |
result = ((random() & 1) == 0 ? |
358 |
deque.getFirst() : deque.element()); |
359 |
} catch (NoSuchElementException e) { |
360 |
threw = true; |
361 |
} |
362 |
if (!threw) |
363 |
throw new Exception("getFirst-no exception: "+result); |
364 |
threw = false; |
365 |
try { |
366 |
result = deque.getLast(); |
367 |
} catch (NoSuchElementException e) { |
368 |
threw = true; |
369 |
} |
370 |
if (!threw) |
371 |
throw new Exception("getLast-no exception: "+result); |
372 |
} |
373 |
|
374 |
} |
375 |
} |