/*
 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */

package java.util;

import java.util.concurrent.atomic.AtomicLong;
import java.util.function.DoubleConsumer;
import java.util.function.IntConsumer;
import java.util.function.LongConsumer;
import java.util.stream.DoubleStream;
import java.util.stream.IntStream;
import java.util.stream.LongStream;
import java.util.stream.StreamSupport;

/**
 * A generator of uniform pseudorandom values applicable for use in
 * (among other contexts) isolated parallel computations that may
 * generate subtasks. Class {@code SplittableRandom} supports methods for
 * producing pseudorandom numbers of type {@code int}, {@code long},
 * and {@code double} with similar usages as for class
 * {@link java.util.Random} but differs in the following ways:
 *
 * <ul>
 *
 * <li>Series of generated values pass the DieHarder suite testing
 * independence and uniformity properties of random number generators.
 * (Most recently validated with <a
 * href="http://www.phy.duke.edu/~rgb/General/dieharder.php"> version
 * 3.31.1</a>.) These tests validate only the methods for certain
 * types and ranges, but similar properties are expected to hold, at
 * least approximately, for others as well. The <em>period</em>
 * (length of any series of generated values before it repeats) is at
 * least 2<sup>64</sup>.
 *
 * <li>Method {@link #split} constructs and returns a new
 * SplittableRandom instance that shares no mutable state with the
 * current instance. However, with very high probability, the
 * values collectively generated by the two objects have the same
 * statistical properties as if the same quantity of values were
 * generated by a single thread using a single {@code
 * SplittableRandom} object.
 *
 * <li>Instances of SplittableRandom are <em>not</em> thread-safe.
 * They are designed to be split, not shared, across threads. For
 * example, a {@link java.util.concurrent.ForkJoinTask
 * fork/join-style} computation using random numbers might include a
 * construction of the form {@code new
 * Subtask(aSplittableRandom.split()).fork()}.
 *
 * <li>This class provides additional methods for generating random
 * streams, that employ the above techniques when used in {@code
 * stream.parallel()} mode.
 *
 * </ul>
 *
 * <p>Instances of {@code SplittableRandom} are not cryptographically
 * secure. Consider instead using {@link java.security.SecureRandom}
 * in security-sensitive applications. Additionally,
 * default-constructed instances do not use a cryptographically random
 * seed unless the {@linkplain System#getProperty system property}
 * {@code java.util.secureRandomSeed} is set to {@code true}.
 *
 * @author Guy Steele
 * @author Doug Lea
 * @since 1.8
 */
public final class SplittableRandom {

 /*
 * Implementation Overview.
 *
 * This algorithm was inspired by the "DotMix" algorithm by
 * Leiserson, Schardl, and Sukha "Deterministic Parallel
 * Random-Number Generation for Dynamic-Multithreading Platforms",
 * PPoPP 2012, as well as those in "Parallel random numbers: as
 * easy as 1, 2, 3" by Salmon, Morae, Dror, and Shaw, SC 2011. It
 * differs mainly in simplifying and cheapening operations.
 *
 * The primary update step (method nextSeed()) is to add a
 * constant ("gamma") to the current (64 bit) seed, forming a
 * simple sequence. The seed and the gamma values for any two
 * SplittableRandom instances are highly likely to be different.
 *
 * Methods nextLong, nextInt, and derivatives do not return the
 * sequence (seed) values, but instead a hash-like bit-mix of
 * their bits, producing more independently distributed sequences.
 * For nextLong, the mix64 function is based on David Stafford's
 * (http://zimbry.blogspot.com/2011/09/better-bit-mixing-improving-on.html)
 * "Mix13" variant of the "64-bit finalizer" function in Austin
 * Appleby's MurmurHash3 algorithm (see
 * http://code.google.com/p/smhasher/wiki/MurmurHash3). The mix32
 * function is based on Stafford's Mix04 mix function, but returns
 * the upper 32 bits cast as int.
 *
 * The split operation uses the current generator to form the seed
 * and gamma for another SplittableRandom. To conservatively
 * avoid potential correlations between seed and value generation,
 * gamma selection (method mixGamma) uses different
 * (Murmurhash3's) mix constants. To avoid potential weaknesses
 * in bit-mixing transformations, we restrict gammas to odd values
 * with at least 24 0-1 or 1-0 bit transitions. Rather than
 * rejecting candidates with too few or too many bits set, method
 * mixGamma flips some bits (which has the effect of mapping at
 * most 4 to any given gamma value). This reduces the effective
 * set of 64bit odd gamma values by about 2%, and serves as an
 * automated screening for sequence constant selection that is
 * left as an empirical decision in some other hashing and crypto
 * algorithms.
 *
 * The resulting generator thus transforms a sequence in which
 * (typically) many bits change on each step, with an inexpensive
 * mixer with good (but less than cryptographically secure)
 * avalanching.
 *
 * The default (no-argument) constructor, in essence, invokes
 * split() for a common "defaultGen" SplittableRandom. Unlike
 * other cases, this split must be performed in a thread-safe
 * manner, so we use an AtomicLong to represent the seed rather
 * than use an explicit SplittableRandom. To bootstrap the
 * defaultGen, we start off using a seed based on current time
 * unless the java.util.secureRandomSeed property is set. This
 * serves as a slimmed-down (and insecure) variant of SecureRandom
 * that also avoids stalls that may occur when using /dev/random.
 *
 * It is a relatively simple matter to apply the basic design here
 * to use 128 bit seeds. However, emulating 128bit arithmetic and
 * carrying around twice the state add more overhead than appears
 * warranted for current usages.
 *
 * File organization: First the non-public methods that constitute
 * the main algorithm, then the main public methods, followed by
 * some custom spliterator classes needed for stream methods.
 */

 /**
 * The golden ratio scaled to 64bits, used as the initial gamma
 * value for (unsplit) SplittableRandoms.
 */
 private static final long GOLDEN_GAMMA = 0x9e3779b97f4a7c15L;

 /**
 * The least non-zero value returned by nextDouble(). This value
 * is scaled by a random value of 53 bits to produce a result.
 */
 private static final double DOUBLE_UNIT = 0x1.0p-53; // 1.0 / (1L << 53);

 /**
 * The seed. Updated only via method nextSeed.
 */
 private long seed;

 /**
 * The step value.
 */
 private final long gamma;

 /**
 * Internal constructor used by all others except default constructor.
 */
 private SplittableRandom(long seed, long gamma) {
 this.seed = seed;
 this.gamma = gamma;
 }

 /**
 * Computes Stafford variant 13 of 64bit mix function.
 */
 private static long mix64(long z) {
 z = (z ^ (z >>> 30)) * 0xbf58476d1ce4e5b9L;
 z = (z ^ (z >>> 27)) * 0x94d049bb133111ebL;
 return z ^ (z >>> 31);
 }

 /**
 * Returns the 32 high bits of Stafford variant 4 mix64 function as int.
 */
 private static int mix32(long z) {
 z = (z ^ (z >>> 33)) * 0x62a9d9ed799705f5L;
 return (int)(((z ^ (z >>> 28)) * 0xcb24d0a5c88c35b3L) >>> 32);
 }

 /**
 * Returns the gamma value to use for a new split instance.
 */
 private static long mixGamma(long z) {
 z = (z ^ (z >>> 33)) * 0xff51afd7ed558ccdL; // MurmurHash3 mix constants
 z = (z ^ (z >>> 33)) * 0xc4ceb9fe1a85ec53L;
 z = (z ^ (z >>> 33)) | 1L; // force to be odd
 int n = Long.bitCount(z ^ (z >>> 1)); // ensure enough transitions
 return (n < 24) ? z ^ 0xaaaaaaaaaaaaaaaaL : z;
 }

 /**
 * Adds gamma to seed.
 */
 private long nextSeed() {
 return seed += gamma;
 }

 // IllegalArgumentException messages
 static final String BAD_BOUND = "bound must be positive";
 static final String BAD_RANGE = "bound must be greater than origin";
 static final String BAD_SIZE = "size must be non-negative";

 /**
 * The seed generator for default constructors.
 */
 private static final AtomicLong defaultGen
 = new AtomicLong(mix64(System.currentTimeMillis()) ^
 mix64(System.nanoTime()));

 // at end of <clinit> to survive static initialization circularity
 static {
 if (java.security.AccessController.doPrivileged(
 new java.security.PrivilegedAction<Boolean>() {
 public Boolean run() {
 return Boolean.getBoolean("java.util.secureRandomSeed");
 }})) {
 byte[] seedBytes = java.security.SecureRandom.getSeed(8);
 long s = (long)seedBytes[0] & 0xffL;
 for (int i = 1; i < 8; ++i)
 s = (s << 8) | ((long)seedBytes[i] & 0xffL);
 defaultGen.set(s);
 }
 }

 /*
 * Internal versions of nextX methods used by streams, as well as
 * the public nextX(origin, bound) methods. These exist mainly to
 * avoid the need for multiple versions of stream spliterators
 * across the different exported forms of streams.
 */

 /**
 * The form of nextLong used by LongStream Spliterators. If
 * origin is greater than bound, acts as unbounded form of
 * nextLong, else as bounded form.
 *
 * @param origin the least value, unless greater than bound
 * @param bound the upper bound (exclusive), must not equal origin
 * @return a pseudorandom value
 */
 final long internalNextLong(long origin, long bound) {
 /*
 * Four Cases:
 *
 * 1. If the arguments indicate unbounded form, act as
 * nextLong().
 *
 * 2. If the range is an exact power of two, apply the
 * associated bit mask.
 *
 * 3. If the range is positive, loop to avoid potential bias
 * when the implicit nextLong() bound (2<sup>64</sup>) is not
 * evenly divisible by the range. The loop rejects candidates
 * computed from otherwise over-represented values. The
 * expected number of iterations under an ideal generator
 * varies from 1 to 2, depending on the bound. The loop itself
 * takes an unlovable form. Because the first candidate is
 * already available, we need a break-in-the-middle
 * construction, which is concisely but cryptically performed
 * within the while-condition of a body-less for loop.
 *
 * 4. Otherwise, the range cannot be represented as a positive
 * long. The loop repeatedly generates unbounded longs until
 * obtaining a candidate meeting constraints (with an expected
 * number of iterations of less than two).
 */

 long r = mix64(nextSeed());
 if (origin < bound) {
 long n = bound - origin, m = n - 1;
 if ((n & m) == 0L) // power of two
 r = (r & m) + origin;
 else if (n > 0L) { // reject over-represented candidates
 for (long u = r >>> 1; // ensure nonnegative
 u + m - (r = u % n) < 0L; // rejection check
 u = mix64(nextSeed()) >>> 1) // retry
 ;
 r += origin;
 }
 else { // range not representable as long
 while (r < origin || r >= bound)
 r = mix64(nextSeed());
 }
 }
 return r;
 }

 /**
 * The form of nextInt used by IntStream Spliterators.
 * Exactly the same as long version, except for types.
 *
 * @param origin the least value, unless greater than bound
 * @param bound the upper bound (exclusive), must not equal origin
 * @return a pseudorandom value
 */
 final int internalNextInt(int origin, int bound) {
 int r = mix32(nextSeed());
 if (origin < bound) {
 int n = bound - origin, m = n - 1;
 if ((n & m) == 0)
 r = (r & m) + origin;
 else if (n > 0) {
 for (int u = r >>> 1;
 u + m - (r = u % n) < 0;
 u = mix32(nextSeed()) >>> 1)
 ;
 r += origin;
 }
 else {
 while (r < origin || r >= bound)
 r = mix32(nextSeed());
 }
 }
 return r;
 }

 /**
 * The form of nextDouble used by DoubleStream Spliterators.
 *
 * @param origin the least value, unless greater than bound
 * @param bound the upper bound (exclusive), must not equal origin
 * @return a pseudorandom value
 */
 final double internalNextDouble(double origin, double bound) {
 double r = (nextLong() >>> 11) * DOUBLE_UNIT;
 if (origin < bound) {
 r = r * (bound - origin) + origin;
 if (r >= bound) // correct for rounding
 r = Double.longBitsToDouble(Double.doubleToLongBits(bound) - 1);
 }
 return r;
 }

 /* ---------------- public methods ---------------- */

 /**
 * Creates a new SplittableRandom instance using the specified
 * initial seed. SplittableRandom instances created with the same
 * seed in the same program generate identical sequences of values.
 *
 * @param seed the initial seed
 */
 public SplittableRandom(long seed) {
 this(seed, GOLDEN_GAMMA);
 }

 /**
 * Creates a new SplittableRandom instance that is likely to
 * generate sequences of values that are statistically independent
 * of those of any other instances in the current program; and
 * may, and typically does, vary across program invocations.
 */
 public SplittableRandom() { // emulate defaultGen.split()
 long s = defaultGen.getAndAdd(GOLDEN_GAMMA << 1);
 this.seed = mix64(s);
 this.gamma = mixGamma(s + GOLDEN_GAMMA);
 }

 /**
 * Constructs and returns a new SplittableRandom instance that
 * shares no mutable state with this instance. However, with very
 * high probability, the set of values collectively generated by
 * the two objects has the same statistical properties as if the
 * same quantity of values were generated by a single thread using
 * a single SplittableRandom object. Either or both of the two
 * objects may be further split using the {@code split()} method,
 * and the same expected statistical properties apply to the
 * entire set of generators constructed by such recursive
 * splitting.
 *
 * @return the new SplittableRandom instance
 */
 public SplittableRandom split() {
 return new SplittableRandom(nextLong(), mixGamma(nextSeed()));
 }

 /**
 * Fills a user-supplied byte array with generated pseudorandom bytes.
 *
 * @param bytes the byte array to fill with pseudorandom bytes
 * @throws NullPointerException if bytes is null
 * @since 10
 */
 public void nextBytes(byte[] bytes) {
 int i = 0;
 int len = bytes.length;
 for (int words = len >> 3; words--> 0; ) {
 long rnd = nextLong();
 for (int n = 8; n--> 0; rnd >>>= Byte.SIZE)
 bytes[i++] = (byte)rnd;
 }
 if (i < len)
 for (long rnd = nextLong(); i < len; rnd >>>= Byte.SIZE)
 bytes[i++] = (byte)rnd;
 }

 /**
 * Returns a pseudorandom {@code int} value.
 *
 * @return a pseudorandom {@code int} value
 */
 public int nextInt() {
 return mix32(nextSeed());
 }

 /**
 * Returns a pseudorandom {@code int} value between zero (inclusive)
 * and the specified bound (exclusive).
 *
 * @param bound the upper bound (exclusive). Must be positive.
 * @return a pseudorandom {@code int} value between zero
 * (inclusive) and the bound (exclusive)
 * @throws IllegalArgumentException if {@code bound} is not positive
 */
 public int nextInt(int bound) {
 if (bound <= 0)
 throw new IllegalArgumentException(BAD_BOUND);
 // Specialize internalNextInt for origin 0
 int r = mix32(nextSeed());
 int m = bound - 1;
 if ((bound & m) == 0) // power of two
 r &= m;
 else { // reject over-represented candidates
 for (int u = r >>> 1;
 u + m - (r = u % bound) < 0;
 u = mix32(nextSeed()) >>> 1)
 ;
 }
 return r;
 }

 /**
 * Returns a pseudorandom {@code int} value between the specified
 * origin (inclusive) and the specified bound (exclusive).
 *
 * @param origin the least value returned
 * @param bound the upper bound (exclusive)
 * @return a pseudorandom {@code int} value between the origin
 * (inclusive) and the bound (exclusive)
 * @throws IllegalArgumentException if {@code origin} is greater than
 * or equal to {@code bound}
 */
 public int nextInt(int origin, int bound) {
 if (origin >= bound)
 throw new IllegalArgumentException(BAD_RANGE);
 return internalNextInt(origin, bound);
 }

 /**
 * Returns a pseudorandom {@code long} value.
 *
 * @return a pseudorandom {@code long} value
 */
 public long nextLong() {
 return mix64(nextSeed());
 }

 /**
 * Returns a pseudorandom {@code long} value between zero (inclusive)
 * and the specified bound (exclusive).
 *
 * @param bound the upper bound (exclusive). Must be positive.
 * @return a pseudorandom {@code long} value between zero
 * (inclusive) and the bound (exclusive)
 * @throws IllegalArgumentException if {@code bound} is not positive
 */
 public long nextLong(long bound) {
 if (bound <= 0)
 throw new IllegalArgumentException(BAD_BOUND);
 // Specialize internalNextLong for origin 0
 long r = mix64(nextSeed());
 long m = bound - 1;
 if ((bound & m) == 0L) // power of two
 r &= m;
 else { // reject over-represented candidates
 for (long u = r >>> 1;
 u + m - (r = u % bound) < 0L;
 u = mix64(nextSeed()) >>> 1)
 ;
 }
 return r;
 }

 /**
 * Returns a pseudorandom {@code long} value between the specified
 * origin (inclusive) and the specified bound (exclusive).
 *
 * @param origin the least value returned
 * @param bound the upper bound (exclusive)
 * @return a pseudorandom {@code long} value between the origin
 * (inclusive) and the bound (exclusive)
 * @throws IllegalArgumentException if {@code origin} is greater than
 * or equal to {@code bound}
 */
 public long nextLong(long origin, long bound) {
 if (origin >= bound)
 throw new IllegalArgumentException(BAD_RANGE);
 return internalNextLong(origin, bound);
 }

 /**
 * Returns a pseudorandom {@code double} value between zero
 * (inclusive) and one (exclusive).
 *
 * @return a pseudorandom {@code double} value between zero
 * (inclusive) and one (exclusive)
 */
 public double nextDouble() {
 return (mix64(nextSeed()) >>> 11) * DOUBLE_UNIT;
 }

 /**
 * Returns a pseudorandom {@code double} value between 0.0
 * (inclusive) and the specified bound (exclusive).
 *
 * @param bound the upper bound (exclusive). Must be positive.
 * @return a pseudorandom {@code double} value between zero
 * (inclusive) and the bound (exclusive)
 * @throws IllegalArgumentException if {@code bound} is not positive
 */
 public double nextDouble(double bound) {
 if (!(bound > 0.0))
 throw new IllegalArgumentException(BAD_BOUND);
 double result = (mix64(nextSeed()) >>> 11) * DOUBLE_UNIT * bound;
 return (result < bound) ? result : // correct for rounding
 Double.longBitsToDouble(Double.doubleToLongBits(bound) - 1);
 }

 /**
 * Returns a pseudorandom {@code double} value between the specified
 * origin (inclusive) and bound (exclusive).
 *
 * @param origin the least value returned
 * @param bound the upper bound (exclusive)
 * @return a pseudorandom {@code double} value between the origin
 * (inclusive) and the bound (exclusive)
 * @throws IllegalArgumentException if {@code origin} is greater than
 * or equal to {@code bound}
 */
 public double nextDouble(double origin, double bound) {
 if (!(origin < bound))
 throw new IllegalArgumentException(BAD_RANGE);
 return internalNextDouble(origin, bound);
 }

 /**
 * Returns a pseudorandom {@code boolean} value.
 *
 * @return a pseudorandom {@code boolean} value
 */
 public boolean nextBoolean() {
 return mix32(nextSeed()) < 0;
 }

 // stream methods, coded in a way intended to better isolate for
 // maintenance purposes the small differences across forms.

 /**
 * Returns a stream producing the given {@code streamSize} number
 * of pseudorandom {@code int} values from this generator and/or
 * one split from it.
 *
 * @param streamSize the number of values to generate
 * @return a stream of pseudorandom {@code int} values
 * @throws IllegalArgumentException if {@code streamSize} is
 * less than zero
 */
 public IntStream ints(long streamSize) {
 if (streamSize < 0L)
 throw new IllegalArgumentException(BAD_SIZE);
 return StreamSupport.intStream
 (new RandomIntsSpliterator
 (this, 0L, streamSize, Integer.MAX_VALUE, 0),
 false);
 }

 /**
 * Returns an effectively unlimited stream of pseudorandom {@code int}
 * values from this generator and/or one split from it.
 *
 * @implNote This method is implemented to be equivalent to {@code
 * ints(Long.MAX_VALUE)}.
 *
 * @return a stream of pseudorandom {@code int} values
 */
 public IntStream ints() {
 return StreamSupport.intStream
 (new RandomIntsSpliterator
 (this, 0L, Long.MAX_VALUE, Integer.MAX_VALUE, 0),
 false);
 }

 /**
 * Returns a stream producing the given {@code streamSize} number
 * of pseudorandom {@code int} values from this generator and/or one split
 * from it; each value conforms to the given origin (inclusive) and bound
 * (exclusive).
 *
 * @param streamSize the number of values to generate
 * @param randomNumberOrigin the origin (inclusive) of each random value
 * @param randomNumberBound the bound (exclusive) of each random value
 * @return a stream of pseudorandom {@code int} values,
 * each with the given origin (inclusive) and bound (exclusive)
 * @throws IllegalArgumentException if {@code streamSize} is
 * less than zero, or {@code randomNumberOrigin}
 * is greater than or equal to {@code randomNumberBound}
 */
 public IntStream ints(long streamSize, int randomNumberOrigin,
 int randomNumberBound) {
 if (streamSize < 0L)
 throw new IllegalArgumentException(BAD_SIZE);
 if (randomNumberOrigin >= randomNumberBound)
 throw new IllegalArgumentException(BAD_RANGE);
 return StreamSupport.intStream
 (new RandomIntsSpliterator
 (this, 0L, streamSize, randomNumberOrigin, randomNumberBound),
 false);
 }

 /**
 * Returns an effectively unlimited stream of pseudorandom {@code
 * int} values from this generator and/or one split from it; each value
 * conforms to the given origin (inclusive) and bound (exclusive).
 *
 * @implNote This method is implemented to be equivalent to {@code
 * ints(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
 *
 * @param randomNumberOrigin the origin (inclusive) of each random value
 * @param randomNumberBound the bound (exclusive) of each random value
 * @return a stream of pseudorandom {@code int} values,
 * each with the given origin (inclusive) and bound (exclusive)
 * @throws IllegalArgumentException if {@code randomNumberOrigin}
 * is greater than or equal to {@code randomNumberBound}
 */
 public IntStream ints(int randomNumberOrigin, int randomNumberBound) {
 if (randomNumberOrigin >= randomNumberBound)
 throw new IllegalArgumentException(BAD_RANGE);
 return StreamSupport.intStream
 (new RandomIntsSpliterator
 (this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
 false);
 }

 /**
 * Returns a stream producing the given {@code streamSize} number
 * of pseudorandom {@code long} values from this generator and/or
 * one split from it.
 *
 * @param streamSize the number of values to generate
 * @return a stream of pseudorandom {@code long} values
 * @throws IllegalArgumentException if {@code streamSize} is
 * less than zero
 */
 public LongStream longs(long streamSize) {
 if (streamSize < 0L)
 throw new IllegalArgumentException(BAD_SIZE);
 return StreamSupport.longStream
 (new RandomLongsSpliterator
 (this, 0L, streamSize, Long.MAX_VALUE, 0L),
 false);
 }

 /**
 * Returns an effectively unlimited stream of pseudorandom {@code
 * long} values from this generator and/or one split from it.
 *
 * @implNote This method is implemented to be equivalent to {@code
 * longs(Long.MAX_VALUE)}.
 *
 * @return a stream of pseudorandom {@code long} values
 */
 public LongStream longs() {
 return StreamSupport.longStream
 (new RandomLongsSpliterator
 (this, 0L, Long.MAX_VALUE, Long.MAX_VALUE, 0L),
 false);
 }

 /**
 * Returns a stream producing the given {@code streamSize} number of
 * pseudorandom {@code long} values from this generator and/or one split
 * from it; each value conforms to the given origin (inclusive) and bound
 * (exclusive).
 *
 * @param streamSize the number of values to generate
 * @param randomNumberOrigin the origin (inclusive) of each random value
 * @param randomNumberBound the bound (exclusive) of each random value
 * @return a stream of pseudorandom {@code long} values,
 * each with the given origin (inclusive) and bound (exclusive)
 * @throws IllegalArgumentException if {@code streamSize} is
 * less than zero, or {@code randomNumberOrigin}
 * is greater than or equal to {@code randomNumberBound}
 */
 public LongStream longs(long streamSize, long randomNumberOrigin,
 long randomNumberBound) {
 if (streamSize < 0L)
 throw new IllegalArgumentException(BAD_SIZE);
 if (randomNumberOrigin >= randomNumberBound)
 throw new IllegalArgumentException(BAD_RANGE);
 return StreamSupport.longStream
 (new RandomLongsSpliterator
 (this, 0L, streamSize, randomNumberOrigin, randomNumberBound),
 false);
 }

 /**
 * Returns an effectively unlimited stream of pseudorandom {@code
 * long} values from this generator and/or one split from it; each value
 * conforms to the given origin (inclusive) and bound (exclusive).
 *
 * @implNote This method is implemented to be equivalent to {@code
 * longs(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
 *
 * @param randomNumberOrigin the origin (inclusive) of each random value
 * @param randomNumberBound the bound (exclusive) of each random value
 * @return a stream of pseudorandom {@code long} values,
 * each with the given origin (inclusive) and bound (exclusive)
 * @throws IllegalArgumentException if {@code randomNumberOrigin}
 * is greater than or equal to {@code randomNumberBound}
 */
 public LongStream longs(long randomNumberOrigin, long randomNumberBound) {
 if (randomNumberOrigin >= randomNumberBound)
 throw new IllegalArgumentException(BAD_RANGE);
 return StreamSupport.longStream
 (new RandomLongsSpliterator
 (this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
 false);
 }

 /**
 * Returns a stream producing the given {@code streamSize} number of
 * pseudorandom {@code double} values from this generator and/or one split
 * from it; each value is between zero (inclusive) and one (exclusive).
 *
 * @param streamSize the number of values to generate
 * @return a stream of {@code double} values
 * @throws IllegalArgumentException if {@code streamSize} is
 * less than zero
 */
 public DoubleStream doubles(long streamSize) {
 if (streamSize < 0L)
 throw new IllegalArgumentException(BAD_SIZE);
 return StreamSupport.doubleStream
 (new RandomDoublesSpliterator
 (this, 0L, streamSize, Double.MAX_VALUE, 0.0),
 false);
 }

 /**
 * Returns an effectively unlimited stream of pseudorandom {@code
 * double} values from this generator and/or one split from it; each value
 * is between zero (inclusive) and one (exclusive).
 *
 * @implNote This method is implemented to be equivalent to {@code
 * doubles(Long.MAX_VALUE)}.
 *
 * @return a stream of pseudorandom {@code double} values
 */
 public DoubleStream doubles() {
 return StreamSupport.doubleStream
 (new RandomDoublesSpliterator
 (this, 0L, Long.MAX_VALUE, Double.MAX_VALUE, 0.0),
 false);
 }

 /**
 * Returns a stream producing the given {@code streamSize} number of
 * pseudorandom {@code double} values from this generator and/or one split
 * from it; each value conforms to the given origin (inclusive) and bound
 * (exclusive).
 *
 * @param streamSize the number of values to generate
 * @param randomNumberOrigin the origin (inclusive) of each random value
 * @param randomNumberBound the bound (exclusive) of each random value
 * @return a stream of pseudorandom {@code double} values,
 * each with the given origin (inclusive) and bound (exclusive)
 * @throws IllegalArgumentException if {@code streamSize} is
 * less than zero, or {@code randomNumberOrigin}
 * is greater than or equal to {@code randomNumberBound}
 */
 public DoubleStream doubles(long streamSize, double randomNumberOrigin,
 double randomNumberBound) {
 if (streamSize < 0L)
 throw new IllegalArgumentException(BAD_SIZE);
 if (!(randomNumberOrigin < randomNumberBound))
 throw new IllegalArgumentException(BAD_RANGE);
 return StreamSupport.doubleStream
 (new RandomDoublesSpliterator
 (this, 0L, streamSize, randomNumberOrigin, randomNumberBound),
 false);
 }

 /**
 * Returns an effectively unlimited stream of pseudorandom {@code
 * double} values from this generator and/or one split from it; each value
 * conforms to the given origin (inclusive) and bound (exclusive).
 *
 * @implNote This method is implemented to be equivalent to {@code
 * doubles(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
 *
 * @param randomNumberOrigin the origin (inclusive) of each random value
 * @param randomNumberBound the bound (exclusive) of each random value
 * @return a stream of pseudorandom {@code double} values,
 * each with the given origin (inclusive) and bound (exclusive)
 * @throws IllegalArgumentException if {@code randomNumberOrigin}
 * is greater than or equal to {@code randomNumberBound}
 */
 public DoubleStream doubles(double randomNumberOrigin, double randomNumberBound) {
 if (!(randomNumberOrigin < randomNumberBound))
 throw new IllegalArgumentException(BAD_RANGE);
 return StreamSupport.doubleStream
 (new RandomDoublesSpliterator
 (this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
 false);
 }

 /**
 * Spliterator for int streams. We multiplex the four int
 * versions into one class by treating a bound less than origin as
 * unbounded, and also by treating "infinite" as equivalent to
 * Long.MAX_VALUE. For splits, it uses the standard divide-by-two
 * approach. The long and double versions of this class are
 * identical except for types.
 */
 private static final class RandomIntsSpliterator
 implements Spliterator.OfInt {
 final SplittableRandom rng;
 long index;
 final long fence;
 final int origin;
 final int bound;
 RandomIntsSpliterator(SplittableRandom rng, long index, long fence,
 int origin, int bound) {
 this.rng = rng; this.index = index; this.fence = fence;
 this.origin = origin; this.bound = bound;
 }

 public RandomIntsSpliterator trySplit() {
 long i = index, m = (i + fence) >>> 1;
 return (m <= i) ? null :
 new RandomIntsSpliterator(rng.split(), i, index = m, origin, bound);
 }

 public long estimateSize() {
 return fence - index;
 }

 public int characteristics() {
 return (Spliterator.SIZED | Spliterator.SUBSIZED |
 Spliterator.NONNULL | Spliterator.IMMUTABLE);
 }

 public boolean tryAdvance(IntConsumer consumer) {
 if (consumer == null) throw new NullPointerException();
 long i = index, f = fence;
 if (i < f) {
 consumer.accept(rng.internalNextInt(origin, bound));
 index = i + 1;
 return true;
 }
 return false;
 }

 public void forEachRemaining(IntConsumer consumer) {
 if (consumer == null) throw new NullPointerException();
 long i = index, f = fence;
 if (i < f) {
 index = f;
 SplittableRandom r = rng;
 int o = origin, b = bound;
 do {
 consumer.accept(r.internalNextInt(o, b));
 } while (++i < f);
 }
 }
 }

 /**
 * Spliterator for long streams.
 */
 private static final class RandomLongsSpliterator
 implements Spliterator.OfLong {
 final SplittableRandom rng;
 long index;
 final long fence;
 final long origin;
 final long bound;
 RandomLongsSpliterator(SplittableRandom rng, long index, long fence,
 long origin, long bound) {
 this.rng = rng; this.index = index; this.fence = fence;
 this.origin = origin; this.bound = bound;
 }

 public RandomLongsSpliterator trySplit() {
 long i = index, m = (i + fence) >>> 1;
 return (m <= i) ? null :
 new RandomLongsSpliterator(rng.split(), i, index = m, origin, bound);
 }

 public long estimateSize() {
 return fence - index;
 }

 public int characteristics() {
 return (Spliterator.SIZED | Spliterator.SUBSIZED |
 Spliterator.NONNULL | Spliterator.IMMUTABLE);
 }

 public boolean tryAdvance(LongConsumer consumer) {
 if (consumer == null) throw new NullPointerException();
 long i = index, f = fence;
 if (i < f) {
 consumer.accept(rng.internalNextLong(origin, bound));
 index = i + 1;
 return true;
 }
 return false;
 }

 public void forEachRemaining(LongConsumer consumer) {
 if (consumer == null) throw new NullPointerException();
 long i = index, f = fence;
 if (i < f) {
 index = f;
 SplittableRandom r = rng;
 long o = origin, b = bound;
 do {
 consumer.accept(r.internalNextLong(o, b));
 } while (++i < f);
 }
 }

 }

 /**
 * Spliterator for double streams.
 */
 private static final class RandomDoublesSpliterator
 implements Spliterator.OfDouble {
 final SplittableRandom rng;
 long index;
 final long fence;
 final double origin;
 final double bound;
 RandomDoublesSpliterator(SplittableRandom rng, long index, long fence,
 double origin, double bound) {
 this.rng = rng; this.index = index; this.fence = fence;
 this.origin = origin; this.bound = bound;
 }

 public RandomDoublesSpliterator trySplit() {
 long i = index, m = (i + fence) >>> 1;
 return (m <= i) ? null :
 new RandomDoublesSpliterator(rng.split(), i, index = m, origin, bound);
 }

 public long estimateSize() {
 return fence - index;
 }

 public int characteristics() {
 return (Spliterator.SIZED | Spliterator.SUBSIZED |
 Spliterator.NONNULL | Spliterator.IMMUTABLE);
 }

 public boolean tryAdvance(DoubleConsumer consumer) {
 if (consumer == null) throw new NullPointerException();
 long i = index, f = fence;
 if (i < f) {
 consumer.accept(rng.internalNextDouble(origin, bound));
 index = i + 1;
 return true;
 }
 return false;
 }

 public void forEachRemaining(DoubleConsumer consumer) {
 if (consumer == null) throw new NullPointerException();
 long i = index, f = fence;
 if (i < f) {
 index = f;
 SplittableRandom r = rng;
 double o = origin, b = bound;
 do {
 consumer.accept(r.internalNextDouble(o, b));
 } while (++i < f);
 }
 }
 }

}