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package java.util; |
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import java.net.NetworkInterface; |
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import java.util.concurrent.atomic.AtomicLong; |
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import java.util.function.DoubleConsumer; |
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import java.util.function.IntConsumer; |
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import java.util.function.LongConsumer; |
32 |
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import java.util.function.DoubleConsumer; |
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import java.util.stream.StreamSupport; |
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> |
import java.util.stream.DoubleStream; |
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import java.util.stream.IntStream; |
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import java.util.stream.LongStream; |
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import java.util.stream.DoubleStream; |
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import java.util.stream.StreamSupport; |
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|
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/** |
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* A generator of uniform pseudorandom values applicable for use in |
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* types and ranges, but similar properties are expected to hold, at |
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* least approximately, for others as well. The <em>period</em> |
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* (length of any series of generated values before it repeats) is at |
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* least 2<sup>64</sup>. </li> |
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* least 2<sup>64</sup>. |
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* |
57 |
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* <li> Method {@link #split} constructs and returns a new |
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* <li>Method {@link #split} constructs and returns a new |
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* SplittableRandom instance that shares no mutable state with the |
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* current instance. However, with very high probability, the |
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* values collectively generated by the two objects have the same |
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* statistical properties as if the same quantity of values were |
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* generated by a single thread using a single {@code |
63 |
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* SplittableRandom} object. </li> |
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> |
* SplittableRandom} object. |
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* |
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* <li>Instances of SplittableRandom are <em>not</em> thread-safe. |
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* They are designed to be split, not shared, across threads. For |
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* |
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* <li>This class provides additional methods for generating random |
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* streams, that employ the above techniques when used in {@code |
74 |
< |
* stream.parallel()} mode.</li> |
74 |
> |
* stream.parallel()} mode. |
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* |
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* </ul> |
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* |
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* in security-sensitive applications. Additionally, |
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* default-constructed instances do not use a cryptographically random |
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* seed unless the {@linkplain System#getProperty system property} |
83 |
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* {@code java.util.secureRandomSeed} is set to {@code true}. |
83 |
> |
* {@systemProperty java.util.secureRandomSeed} is set to {@code true}. |
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* |
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* @author Guy Steele |
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* @author Doug Lea |
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* other cases, this split must be performed in a thread-safe |
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* manner, so we use an AtomicLong to represent the seed rather |
141 |
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* than use an explicit SplittableRandom. To bootstrap the |
142 |
< |
* defaultGen, we start off using a seed based on current time and |
143 |
< |
* network interface address unless the java.util.secureRandomSeed |
144 |
< |
* property is set. This serves as a slimmed-down (and insecure) |
145 |
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* variant of SecureRandom that also avoids stalls that may occur |
147 |
< |
* when using /dev/random. |
142 |
> |
* defaultGen, we start off using a seed based on current time |
143 |
> |
* unless the java.util.secureRandomSeed property is set. This |
144 |
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* serves as a slimmed-down (and insecure) variant of SecureRandom |
145 |
> |
* that also avoids stalls that may occur when using /dev/random. |
146 |
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* |
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* It is a relatively simple matter to apply the basic design here |
148 |
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* to use 128 bit seeds. However, emulating 128bit arithmetic and |
219 |
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return seed += gamma; |
220 |
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} |
221 |
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|
222 |
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// IllegalArgumentException messages |
223 |
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static final String BAD_BOUND = "bound must be positive"; |
224 |
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static final String BAD_RANGE = "bound must be greater than origin"; |
225 |
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static final String BAD_SIZE = "size must be non-negative"; |
226 |
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|
227 |
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/** |
228 |
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* The seed generator for default constructors. |
229 |
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*/ |
230 |
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private static final AtomicLong defaultGen = new AtomicLong(initialSeed()); |
231 |
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|
232 |
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private static long initialSeed() { |
233 |
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String pp = java.security.AccessController.doPrivileged( |
234 |
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new sun.security.action.GetPropertyAction( |
235 |
< |
"java.util.secureRandomSeed")); |
236 |
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if (pp != null && pp.equalsIgnoreCase("true")) { |
230 |
> |
private static final AtomicLong defaultGen |
231 |
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= new AtomicLong(mix64(System.currentTimeMillis()) ^ |
232 |
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mix64(System.nanoTime())); |
233 |
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|
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// at end of <clinit> to survive static initialization circularity |
235 |
> |
static { |
236 |
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if (java.security.AccessController.doPrivileged( |
237 |
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new java.security.PrivilegedAction<Boolean>() { |
238 |
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public Boolean run() { |
239 |
> |
return Boolean.getBoolean("java.util.secureRandomSeed"); |
240 |
> |
}})) { |
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byte[] seedBytes = java.security.SecureRandom.getSeed(8); |
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< |
long s = (long)(seedBytes[0]) & 0xffL; |
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> |
long s = (long)seedBytes[0] & 0xffL; |
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for (int i = 1; i < 8; ++i) |
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< |
s = (s << 8) | ((long)(seedBytes[i]) & 0xffL); |
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< |
return s; |
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< |
} |
240 |
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long h = 0L; |
241 |
< |
try { |
242 |
< |
Enumeration<NetworkInterface> ifcs = |
243 |
< |
NetworkInterface.getNetworkInterfaces(); |
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< |
boolean retry = false; // retry once if getHardwareAddress is null |
245 |
< |
while (ifcs.hasMoreElements()) { |
246 |
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NetworkInterface ifc = ifcs.nextElement(); |
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< |
if (!ifc.isVirtual()) { // skip fake addresses |
248 |
< |
byte[] bs = ifc.getHardwareAddress(); |
249 |
< |
if (bs != null) { |
250 |
< |
int n = bs.length; |
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< |
int m = Math.min(n >>> 1, 4); |
252 |
< |
for (int i = 0; i < m; ++i) |
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< |
h = (h << 16) ^ (bs[i] << 8) ^ bs[n-1-i]; |
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< |
if (m < 4) |
255 |
< |
h = (h << 8) ^ bs[n-1-m]; |
256 |
< |
h = mix64(h); |
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break; |
258 |
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} |
259 |
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else if (!retry) |
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retry = true; |
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else |
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break; |
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< |
} |
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} |
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} catch (Exception ignore) { |
244 |
> |
s = (s << 8) | ((long)seedBytes[i] & 0xffL); |
245 |
> |
defaultGen.set(s); |
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} |
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return (h ^ mix64(System.currentTimeMillis()) ^ |
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– |
mix64(System.nanoTime())); |
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} |
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|
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// IllegalArgumentException messages |
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static final String BadBound = "bound must be positive"; |
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static final String BadRange = "bound must be greater than origin"; |
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static final String BadSize = "size must be non-negative"; |
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|
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/* |
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* Internal versions of nextX methods used by streams, as well as |
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* the public nextX(origin, bound) methods. These exist mainly to |
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* may, and typically does, vary across program invocations. |
376 |
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*/ |
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public SplittableRandom() { // emulate defaultGen.split() |
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< |
long s = defaultGen.getAndAdd(2 * GOLDEN_GAMMA); |
378 |
> |
long s = defaultGen.getAndAdd(GOLDEN_GAMMA << 1); |
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this.seed = mix64(s); |
380 |
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this.gamma = mixGamma(s + GOLDEN_GAMMA); |
381 |
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} |
399 |
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} |
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|
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/** |
402 |
+ |
* Fills a user-supplied byte array with generated pseudorandom bytes. |
403 |
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* |
404 |
+ |
* @param bytes the byte array to fill with pseudorandom bytes |
405 |
+ |
* @throws NullPointerException if bytes is null |
406 |
+ |
* @since 10 |
407 |
+ |
*/ |
408 |
+ |
public void nextBytes(byte[] bytes) { |
409 |
+ |
int i = 0; |
410 |
+ |
int len = bytes.length; |
411 |
+ |
for (int words = len >> 3; words--> 0; ) { |
412 |
+ |
long rnd = nextLong(); |
413 |
+ |
for (int n = 8; n--> 0; rnd >>>= Byte.SIZE) |
414 |
+ |
bytes[i++] = (byte)rnd; |
415 |
+ |
} |
416 |
+ |
if (i < len) |
417 |
+ |
for (long rnd = nextLong(); i < len; rnd >>>= Byte.SIZE) |
418 |
+ |
bytes[i++] = (byte)rnd; |
419 |
+ |
} |
420 |
+ |
|
421 |
+ |
/** |
422 |
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* Returns a pseudorandom {@code int} value. |
423 |
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* |
424 |
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* @return a pseudorandom {@code int} value |
438 |
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*/ |
439 |
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public int nextInt(int bound) { |
440 |
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if (bound <= 0) |
441 |
< |
throw new IllegalArgumentException(BadBound); |
441 |
> |
throw new IllegalArgumentException(BAD_BOUND); |
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// Specialize internalNextInt for origin 0 |
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int r = mix32(nextSeed()); |
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int m = bound - 1; |
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*/ |
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public int nextInt(int origin, int bound) { |
468 |
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if (origin >= bound) |
469 |
< |
throw new IllegalArgumentException(BadRange); |
469 |
> |
throw new IllegalArgumentException(BAD_RANGE); |
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return internalNextInt(origin, bound); |
471 |
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} |
472 |
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|
490 |
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*/ |
491 |
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public long nextLong(long bound) { |
492 |
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if (bound <= 0) |
493 |
< |
throw new IllegalArgumentException(BadBound); |
493 |
> |
throw new IllegalArgumentException(BAD_BOUND); |
494 |
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// Specialize internalNextLong for origin 0 |
495 |
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long r = mix64(nextSeed()); |
496 |
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long m = bound - 1; |
518 |
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*/ |
519 |
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public long nextLong(long origin, long bound) { |
520 |
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if (origin >= bound) |
521 |
< |
throw new IllegalArgumentException(BadRange); |
521 |
> |
throw new IllegalArgumentException(BAD_RANGE); |
522 |
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return internalNextLong(origin, bound); |
523 |
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} |
524 |
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|
544 |
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*/ |
545 |
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public double nextDouble(double bound) { |
546 |
|
if (!(bound > 0.0)) |
547 |
< |
throw new IllegalArgumentException(BadBound); |
547 |
> |
throw new IllegalArgumentException(BAD_BOUND); |
548 |
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double result = (mix64(nextSeed()) >>> 11) * DOUBLE_UNIT * bound; |
549 |
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return (result < bound) ? result : // correct for rounding |
550 |
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Double.longBitsToDouble(Double.doubleToLongBits(bound) - 1); |
563 |
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*/ |
564 |
|
public double nextDouble(double origin, double bound) { |
565 |
|
if (!(origin < bound)) |
566 |
< |
throw new IllegalArgumentException(BadRange); |
566 |
> |
throw new IllegalArgumentException(BAD_RANGE); |
567 |
|
return internalNextDouble(origin, bound); |
568 |
|
} |
569 |
|
|
591 |
|
*/ |
592 |
|
public IntStream ints(long streamSize) { |
593 |
|
if (streamSize < 0L) |
594 |
< |
throw new IllegalArgumentException(BadSize); |
594 |
> |
throw new IllegalArgumentException(BAD_SIZE); |
595 |
|
return StreamSupport.intStream |
596 |
|
(new RandomIntsSpliterator |
597 |
|
(this, 0L, streamSize, Integer.MAX_VALUE, 0), |
632 |
|
public IntStream ints(long streamSize, int randomNumberOrigin, |
633 |
|
int randomNumberBound) { |
634 |
|
if (streamSize < 0L) |
635 |
< |
throw new IllegalArgumentException(BadSize); |
635 |
> |
throw new IllegalArgumentException(BAD_SIZE); |
636 |
|
if (randomNumberOrigin >= randomNumberBound) |
637 |
< |
throw new IllegalArgumentException(BadRange); |
637 |
> |
throw new IllegalArgumentException(BAD_RANGE); |
638 |
|
return StreamSupport.intStream |
639 |
|
(new RandomIntsSpliterator |
640 |
|
(this, 0L, streamSize, randomNumberOrigin, randomNumberBound), |
658 |
|
*/ |
659 |
|
public IntStream ints(int randomNumberOrigin, int randomNumberBound) { |
660 |
|
if (randomNumberOrigin >= randomNumberBound) |
661 |
< |
throw new IllegalArgumentException(BadRange); |
661 |
> |
throw new IllegalArgumentException(BAD_RANGE); |
662 |
|
return StreamSupport.intStream |
663 |
|
(new RandomIntsSpliterator |
664 |
|
(this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound), |
677 |
|
*/ |
678 |
|
public LongStream longs(long streamSize) { |
679 |
|
if (streamSize < 0L) |
680 |
< |
throw new IllegalArgumentException(BadSize); |
680 |
> |
throw new IllegalArgumentException(BAD_SIZE); |
681 |
|
return StreamSupport.longStream |
682 |
|
(new RandomLongsSpliterator |
683 |
|
(this, 0L, streamSize, Long.MAX_VALUE, 0L), |
718 |
|
public LongStream longs(long streamSize, long randomNumberOrigin, |
719 |
|
long randomNumberBound) { |
720 |
|
if (streamSize < 0L) |
721 |
< |
throw new IllegalArgumentException(BadSize); |
721 |
> |
throw new IllegalArgumentException(BAD_SIZE); |
722 |
|
if (randomNumberOrigin >= randomNumberBound) |
723 |
< |
throw new IllegalArgumentException(BadRange); |
723 |
> |
throw new IllegalArgumentException(BAD_RANGE); |
724 |
|
return StreamSupport.longStream |
725 |
|
(new RandomLongsSpliterator |
726 |
|
(this, 0L, streamSize, randomNumberOrigin, randomNumberBound), |
744 |
|
*/ |
745 |
|
public LongStream longs(long randomNumberOrigin, long randomNumberBound) { |
746 |
|
if (randomNumberOrigin >= randomNumberBound) |
747 |
< |
throw new IllegalArgumentException(BadRange); |
747 |
> |
throw new IllegalArgumentException(BAD_RANGE); |
748 |
|
return StreamSupport.longStream |
749 |
|
(new RandomLongsSpliterator |
750 |
|
(this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound), |
763 |
|
*/ |
764 |
|
public DoubleStream doubles(long streamSize) { |
765 |
|
if (streamSize < 0L) |
766 |
< |
throw new IllegalArgumentException(BadSize); |
766 |
> |
throw new IllegalArgumentException(BAD_SIZE); |
767 |
|
return StreamSupport.doubleStream |
768 |
|
(new RandomDoublesSpliterator |
769 |
|
(this, 0L, streamSize, Double.MAX_VALUE, 0.0), |
799 |
|
* @return a stream of pseudorandom {@code double} values, |
800 |
|
* each with the given origin (inclusive) and bound (exclusive) |
801 |
|
* @throws IllegalArgumentException if {@code streamSize} is |
802 |
< |
* less than zero |
810 |
< |
* @throws IllegalArgumentException if {@code randomNumberOrigin} |
802 |
> |
* less than zero, or {@code randomNumberOrigin} |
803 |
|
* is greater than or equal to {@code randomNumberBound} |
804 |
|
*/ |
805 |
|
public DoubleStream doubles(long streamSize, double randomNumberOrigin, |
806 |
|
double randomNumberBound) { |
807 |
|
if (streamSize < 0L) |
808 |
< |
throw new IllegalArgumentException(BadSize); |
808 |
> |
throw new IllegalArgumentException(BAD_SIZE); |
809 |
|
if (!(randomNumberOrigin < randomNumberBound)) |
810 |
< |
throw new IllegalArgumentException(BadRange); |
810 |
> |
throw new IllegalArgumentException(BAD_RANGE); |
811 |
|
return StreamSupport.doubleStream |
812 |
|
(new RandomDoublesSpliterator |
813 |
|
(this, 0L, streamSize, randomNumberOrigin, randomNumberBound), |
831 |
|
*/ |
832 |
|
public DoubleStream doubles(double randomNumberOrigin, double randomNumberBound) { |
833 |
|
if (!(randomNumberOrigin < randomNumberBound)) |
834 |
< |
throw new IllegalArgumentException(BadRange); |
834 |
> |
throw new IllegalArgumentException(BAD_RANGE); |
835 |
|
return StreamSupport.doubleStream |
836 |
|
(new RandomDoublesSpliterator |
837 |
|
(this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound), |
846 |
|
* approach. The long and double versions of this class are |
847 |
|
* identical except for types. |
848 |
|
*/ |
849 |
< |
static final class RandomIntsSpliterator implements Spliterator.OfInt { |
849 |
> |
private static final class RandomIntsSpliterator |
850 |
> |
implements Spliterator.OfInt { |
851 |
|
final SplittableRandom rng; |
852 |
|
long index; |
853 |
|
final long fence; |
902 |
|
/** |
903 |
|
* Spliterator for long streams. |
904 |
|
*/ |
905 |
< |
static final class RandomLongsSpliterator implements Spliterator.OfLong { |
905 |
> |
private static final class RandomLongsSpliterator |
906 |
> |
implements Spliterator.OfLong { |
907 |
|
final SplittableRandom rng; |
908 |
|
long index; |
909 |
|
final long fence; |
959 |
|
/** |
960 |
|
* Spliterator for double streams. |
961 |
|
*/ |
962 |
< |
static final class RandomDoublesSpliterator implements Spliterator.OfDouble { |
962 |
> |
private static final class RandomDoublesSpliterator |
963 |
> |
implements Spliterator.OfDouble { |
964 |
|
final SplittableRandom rng; |
965 |
|
long index; |
966 |
|
final long fence; |