--- a/src/java.base/share/classes/java/util/SplittableRandom.java Thu Nov 14 12:36:46 2019 -0400
+++ b/src/java.base/share/classes/java/util/SplittableRandom.java Thu Nov 14 12:39:49 2019 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -22,17 +22,13 @@
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
-
package java.util;
+import java.math.BigInteger;
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;
+import java.util.random.RandomGenerator.SplittableGenerator;
+import java.util.random.RandomSupport;
+import java.util.random.RandomSupport.AbstractSplittableGenerator;
/**
* A generator of uniform pseudorandom values applicable for use in
@@ -52,15 +48,15 @@
* 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>.
+ * least 2<sup>64</sup>. </li>
*
- * <li>Method {@link #split} constructs and returns a new
+ * <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.
+ * SplittableRandom} object. </li>
*
* <li>Instances of SplittableRandom are <em>not</em> thread-safe.
* They are designed to be split, not shared, across threads. For
@@ -71,7 +67,7 @@
*
* <li>This class provides additional methods for generating random
* streams, that employ the above techniques when used in {@code
- * stream.parallel()} mode.
+ * stream.parallel()} mode.</li>
*
* </ul>
*
@@ -80,13 +76,13 @@
* in security-sensitive applications. Additionally,
* default-constructed instances do not use a cryptographically random
* seed unless the {@linkplain System#getProperty system property}
- * {@systemProperty java.util.secureRandomSeed} is set to {@code true}.
+ * {@code java.util.secureRandomSeed} is set to {@code true}.
*
* @author Guy Steele
* @author Doug Lea
* @since 1.8
*/
-public final class SplittableRandom {
+public final class SplittableRandom extends AbstractSplittableGenerator {
/*
* Implementation Overview.
@@ -161,12 +157,6 @@
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;
@@ -186,6 +176,7 @@
/**
* Computes Stafford variant 13 of 64bit mix function.
+ * http://zimbry.blogspot.com/2011/09/better-bit-mixing-improving-on.html
*/
private static long mix64(long z) {
z = (z ^ (z >>> 30)) * 0xbf58476d1ce4e5b9L;
@@ -195,6 +186,7 @@
/**
* Returns the 32 high bits of Stafford variant 4 mix64 function as int.
+ * http://zimbry.blogspot.com/2011/09/better-bit-mixing-improving-on.html
*/
private static int mix32(long z) {
z = (z ^ (z >>> 33)) * 0x62a9d9ed799705f5L;
@@ -203,6 +195,8 @@
/**
* Returns the gamma value to use for a new split instance.
+ * Uses the 64bit mix function from MurmurHash3.
+ * https://github.com/aappleby/smhasher/wiki/MurmurHash3
*/
private static long mixGamma(long z) {
z = (z ^ (z >>> 33)) * 0xff51afd7ed558ccdL; // MurmurHash3 mix constants
@@ -219,141 +213,10 @@
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;
- }
+ private static final AtomicLong defaultGen = new AtomicLong(RandomSupport.initialSeed());
/* ---------------- public methods ---------------- */
@@ -375,11 +238,13 @@
* may, and typically does, vary across program invocations.
*/
public SplittableRandom() { // emulate defaultGen.split()
- long s = defaultGen.getAndAdd(GOLDEN_GAMMA << 1);
+ long s = defaultGen.getAndAdd(2 * GOLDEN_GAMMA);
this.seed = mix64(s);
this.gamma = mixGamma(s + GOLDEN_GAMMA);
}
+ // public SplittableRandom copy() { return new SplittableRandom(seed, gamma); }
+
/**
* Constructs and returns a new SplittableRandom instance that
* shares no mutable state with this instance. However, with very
@@ -398,24 +263,8 @@
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;
+ public SplittableRandom split(SplittableGenerator source) {
+ return new SplittableRandom(source.nextLong(), mixGamma(source.nextLong()));
}
/**
@@ -428,49 +277,6 @@
}
/**
- * 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
@@ -479,537 +285,10 @@
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);
- }
+ static final BigInteger PERIOD = BigInteger.ONE.shiftLeft(64); // Period is 2**64
- /**
- * 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);
- }
- }
+ public BigInteger period() {
+ return PERIOD;
}
}