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* http://creativecommons.org/publicdomain/zero/1.0/ |
5 |
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*/ |
6 |
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|
7 |
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import java.util.Arrays; |
8 |
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import java.util.List; |
9 |
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import java.util.SplittableRandom; |
10 |
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import java.util.concurrent.atomic.AtomicInteger; |
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import java.util.concurrent.atomic.LongAdder; |
12 |
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import java.lang.reflect.Method; |
13 |
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import java.util.function.Predicate; |
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import java.util.stream.Collectors; |
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|
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import junit.framework.Test; |
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import junit.framework.TestSuite; |
530 |
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assertEquals(size, counter.sum()); |
531 |
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} |
532 |
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|
533 |
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/** |
534 |
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* SplittableRandom should implement most of Random's public methods |
535 |
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*/ |
536 |
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public void testShouldImplementMostRandomMethods() throws Throwable { |
537 |
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Predicate<Method> wasForgotten = method -> { |
538 |
+ |
String name = method.getName(); |
539 |
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// some methods deliberately not implemented |
540 |
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if (name.equals("setSeed")) return false; |
541 |
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if (name.equals("nextFloat")) return false; |
542 |
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if (name.equals("nextGaussian")) return false; |
543 |
+ |
try { |
544 |
+ |
SplittableRandom.class.getMethod( |
545 |
+ |
method.getName(), method.getParameterTypes()); |
546 |
+ |
} catch (ReflectiveOperationException ex) { |
547 |
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return true; |
548 |
+ |
} |
549 |
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return false; |
550 |
+ |
}; |
551 |
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List<Method> forgotten = |
552 |
+ |
Arrays.stream(java.util.Random.class.getMethods()) |
553 |
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.filter(wasForgotten) |
554 |
+ |
.collect(Collectors.toList()); |
555 |
+ |
if (!forgotten.isEmpty()) |
556 |
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throw new AssertionError("Please implement: " + forgotten); |
557 |
+ |
} |
558 |
+ |
|
559 |
+ |
/** |
560 |
+ |
* Repeated calls to nextBytes produce at least values of different signs for every byte |
561 |
+ |
*/ |
562 |
+ |
public void testNextBytes() { |
563 |
+ |
SplittableRandom sr = new SplittableRandom(); |
564 |
+ |
int n = sr.nextInt(1, 20); |
565 |
+ |
byte[] bytes = new byte[n]; |
566 |
+ |
outer: |
567 |
+ |
for (int i = 0; i < n; i++) { |
568 |
+ |
for (int tries = NCALLS; tries-->0; ) { |
569 |
+ |
byte before = bytes[i]; |
570 |
+ |
sr.nextBytes(bytes); |
571 |
+ |
byte after = bytes[i]; |
572 |
+ |
if (after * before < 0) |
573 |
+ |
continue outer; |
574 |
+ |
} |
575 |
+ |
fail("not enough variation in random bytes"); |
576 |
+ |
} |
577 |
+ |
} |
578 |
+ |
|
579 |
+ |
/** |
580 |
+ |
* Filling an empty array with random bytes succeeds without effect. |
581 |
+ |
*/ |
582 |
+ |
public void testNextBytes_emptyArray() { |
583 |
+ |
new SplittableRandom().nextBytes(new byte[0]); |
584 |
+ |
} |
585 |
+ |
|
586 |
+ |
public void testNextBytes_nullArray() { |
587 |
+ |
try { |
588 |
+ |
new SplittableRandom().nextBytes(null); |
589 |
+ |
shouldThrow(); |
590 |
+ |
} catch (NullPointerException success) {} |
591 |
+ |
} |
592 |
+ |
|
593 |
|
} |