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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; |
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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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* 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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* |
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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 |
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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 |
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* stream.parallel()} mode.</li> |
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* stream.parallel()} mode. |
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* |
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* </ul> |
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* |
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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 |
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* than use an explicit SplittableRandom. To bootstrap the |
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* defaultGen, we start off using a seed based on current time and |
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* network interface address unless the java.util.secureRandomSeed |
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* property is set. This serves as a slimmed-down (and insecure) |
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* variant of SecureRandom that also avoids stalls that may occur |
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* when using /dev/random. |
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* defaultGen, we start off using a seed based on current time |
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* unless the java.util.secureRandomSeed property is set. This |
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* serves as a slimmed-down (and insecure) variant of SecureRandom |
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* that also avoids stalls that may occur when using /dev/random. |
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* |
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* It is a relatively simple matter to apply the basic design here |
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* to use 128 bit seeds. However, emulating 128bit arithmetic and |
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s = (s << 8) | ((long)(seedBytes[i]) & 0xffL); |
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return s; |
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} |
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long h = 0L; |
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try { |
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Enumeration<NetworkInterface> ifcs = |
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NetworkInterface.getNetworkInterfaces(); |
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boolean retry = false; // retry once if getHardwareAddress is null |
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while (ifcs.hasMoreElements()) { |
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NetworkInterface ifc = ifcs.nextElement(); |
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if (!ifc.isVirtual()) { // skip fake addresses |
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byte[] bs = ifc.getHardwareAddress(); |
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if (bs != null) { |
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int n = bs.length; |
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int m = Math.min(n >>> 1, 4); |
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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) |
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h = (h << 8) ^ bs[n-1-m]; |
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h = mix64(h); |
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break; |
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} |
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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) { |
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} |
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return (h ^ mix64(System.currentTimeMillis()) ^ |
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return (mix64(System.currentTimeMillis()) ^ |
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mix64(System.nanoTime())); |
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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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static final String BAD_BOUND = "bound must be positive"; |
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static final String BAD_RANGE = "bound must be greater than origin"; |
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static final String BAD_SIZE = "size must be non-negative"; |
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/* |
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* Internal versions of nextX methods used by streams, as well as |
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*/ |
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public int nextInt(int bound) { |
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if (bound <= 0) |
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throw new IllegalArgumentException(BadBound); |
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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) { |
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if (origin >= bound) |
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throw new IllegalArgumentException(BadRange); |
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throw new IllegalArgumentException(BAD_RANGE); |
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return internalNextInt(origin, bound); |
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} |
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*/ |
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public long nextLong(long bound) { |
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if (bound <= 0) |
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throw new IllegalArgumentException(BadBound); |
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throw new IllegalArgumentException(BAD_BOUND); |
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// Specialize internalNextLong for origin 0 |
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long r = mix64(nextSeed()); |
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long m = bound - 1; |
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*/ |
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public long nextLong(long origin, long bound) { |
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if (origin >= bound) |
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throw new IllegalArgumentException(BadRange); |
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throw new IllegalArgumentException(BAD_RANGE); |
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return internalNextLong(origin, bound); |
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} |
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*/ |
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public double nextDouble(double bound) { |
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if (!(bound > 0.0)) |
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throw new IllegalArgumentException(BadBound); |
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throw new IllegalArgumentException(BAD_BOUND); |
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double result = (mix64(nextSeed()) >>> 11) * DOUBLE_UNIT * bound; |
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return (result < bound) ? result : // correct for rounding |
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Double.longBitsToDouble(Double.doubleToLongBits(bound) - 1); |
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*/ |
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public double nextDouble(double origin, double bound) { |
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if (!(origin < bound)) |
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throw new IllegalArgumentException(BadRange); |
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throw new IllegalArgumentException(BAD_RANGE); |
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return internalNextDouble(origin, bound); |
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} |
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*/ |
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public IntStream ints(long streamSize) { |
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if (streamSize < 0L) |
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throw new IllegalArgumentException(BadSize); |
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throw new IllegalArgumentException(BAD_SIZE); |
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return StreamSupport.intStream |
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(new RandomIntsSpliterator |
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(this, 0L, streamSize, Integer.MAX_VALUE, 0), |
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public IntStream ints(long streamSize, int randomNumberOrigin, |
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int randomNumberBound) { |
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if (streamSize < 0L) |
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throw new IllegalArgumentException(BadSize); |
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throw new IllegalArgumentException(BAD_SIZE); |
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if (randomNumberOrigin >= randomNumberBound) |
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throw new IllegalArgumentException(BadRange); |
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throw new IllegalArgumentException(BAD_RANGE); |
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return StreamSupport.intStream |
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(new RandomIntsSpliterator |
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(this, 0L, streamSize, randomNumberOrigin, randomNumberBound), |
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*/ |
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public IntStream ints(int randomNumberOrigin, int randomNumberBound) { |
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if (randomNumberOrigin >= randomNumberBound) |
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throw new IllegalArgumentException(BadRange); |
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throw new IllegalArgumentException(BAD_RANGE); |
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return StreamSupport.intStream |
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(new RandomIntsSpliterator |
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(this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound), |
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*/ |
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public LongStream longs(long streamSize) { |
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if (streamSize < 0L) |
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throw new IllegalArgumentException(BadSize); |
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throw new IllegalArgumentException(BAD_SIZE); |
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return StreamSupport.longStream |
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(new RandomLongsSpliterator |
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(this, 0L, streamSize, Long.MAX_VALUE, 0L), |
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public LongStream longs(long streamSize, long randomNumberOrigin, |
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long randomNumberBound) { |
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if (streamSize < 0L) |
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throw new IllegalArgumentException(BadSize); |
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throw new IllegalArgumentException(BAD_SIZE); |
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if (randomNumberOrigin >= randomNumberBound) |
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throw new IllegalArgumentException(BadRange); |
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throw new IllegalArgumentException(BAD_RANGE); |
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return StreamSupport.longStream |
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(new RandomLongsSpliterator |
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(this, 0L, streamSize, randomNumberOrigin, randomNumberBound), |
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*/ |
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public LongStream longs(long randomNumberOrigin, long randomNumberBound) { |
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if (randomNumberOrigin >= randomNumberBound) |
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throw new IllegalArgumentException(BadRange); |
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throw new IllegalArgumentException(BAD_RANGE); |
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return StreamSupport.longStream |
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(new RandomLongsSpliterator |
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(this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound), |
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*/ |
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public DoubleStream doubles(long streamSize) { |
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if (streamSize < 0L) |
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throw new IllegalArgumentException(BadSize); |
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throw new IllegalArgumentException(BAD_SIZE); |
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return StreamSupport.doubleStream |
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(new RandomDoublesSpliterator |
747 |
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(this, 0L, streamSize, Double.MAX_VALUE, 0.0), |
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public DoubleStream doubles(long streamSize, double randomNumberOrigin, |
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double randomNumberBound) { |
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if (streamSize < 0L) |
787 |
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throw new IllegalArgumentException(BadSize); |
787 |
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throw new IllegalArgumentException(BAD_SIZE); |
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if (!(randomNumberOrigin < randomNumberBound)) |
789 |
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throw new IllegalArgumentException(BadRange); |
789 |
> |
throw new IllegalArgumentException(BAD_RANGE); |
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return StreamSupport.doubleStream |
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(new RandomDoublesSpliterator |
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(this, 0L, streamSize, randomNumberOrigin, randomNumberBound), |
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*/ |
811 |
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public DoubleStream doubles(double randomNumberOrigin, double randomNumberBound) { |
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if (!(randomNumberOrigin < randomNumberBound)) |
813 |
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throw new IllegalArgumentException(BadRange); |
813 |
> |
throw new IllegalArgumentException(BAD_RANGE); |
814 |
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return StreamSupport.doubleStream |
815 |
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(new RandomDoublesSpliterator |
816 |
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(this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound), |
825 |
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* approach. The long and double versions of this class are |
826 |
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* identical except for types. |
827 |
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*/ |
828 |
< |
static final class RandomIntsSpliterator implements Spliterator.OfInt { |
828 |
> |
private static final class RandomIntsSpliterator |
829 |
> |
implements Spliterator.OfInt { |
830 |
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final SplittableRandom rng; |
831 |
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long index; |
832 |
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final long fence; |
881 |
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/** |
882 |
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* Spliterator for long streams. |
883 |
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*/ |
884 |
< |
static final class RandomLongsSpliterator implements Spliterator.OfLong { |
884 |
> |
private static final class RandomLongsSpliterator |
885 |
> |
implements Spliterator.OfLong { |
886 |
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final SplittableRandom rng; |
887 |
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long index; |
888 |
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final long fence; |
938 |
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/** |
939 |
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* Spliterator for double streams. |
940 |
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*/ |
941 |
< |
static final class RandomDoublesSpliterator implements Spliterator.OfDouble { |
941 |
> |
private static final class RandomDoublesSpliterator |
942 |
> |
implements Spliterator.OfDouble { |
943 |
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final SplittableRandom rng; |
944 |
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long index; |
945 |
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final long fence; |