--- a/src/java.base/share/classes/java/util/JumpableRng.java Thu Jun 27 16:46:44 2019 -0300
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,178 +0,0 @@
-/*
- * 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
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation. Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-package java.util;
-
-import java.math.BigInteger;
-import java.util.stream.Stream;
-
-/**
- * This interface is designed to provide a common protocol for objects
- * that generate pseudorandom sequences of numbers (or Boolean values)
- * and furthermore can easily <i>jump</i> forward (by a fixed amount)
- * to a distant point in the state cycle.
- *
- * <p>Ideally, all {@code JumpableRng} objects produced by iterative
- * jumping from a single original {@code JumpableRng} object are
- * statistically independent of one another and individually uniform.
- * In practice, one must settle for some approximation to independence
- * and uniformity. In particular, a specific implementation may
- * assume that each generator in a stream produced by the {@code jumps}
- * method is used to produce a number of values no larger than either
- * 2<sup>64</sup> or the square root of its period. Implementors are
- * advised to use algorithms whose period is at least 2<sup>127</sup>.
- *
- * <p>Methods are provided to perform a single jump operation and also
- * to produce a stream of generators produced from the original by
- * iterative copying and jumping of internal state. A typical
- * strategy for a multithreaded application is to create a single
- * {@code JumpableRng} object, calls its {@code jumps} method exactly
- * once, and then parcel out generators from the resulting stream, one
- * to each thread. It is generally not a good idea to call {@code jump}
- * on a generator that was itself produced by the {@code jumps} method,
- * because the result may be a generator identical to another
- * generator already produce by that call to the {@code jumps} method.
- * For this reason, the return type of the {@code jumps} method is
- * {@code Stream<Rng>} rather than {@code Stream<JumpableRng>}, even
- * though the actual generator objects in that stream likely do also
- * implement the {@code JumpableRng} interface.
- *
- * <p>An implementation of the {@code JumpableRng} interface must provide
- * concrete definitions for the methods {@code nextInt()}, {@code nextLong},
- * {@code period()}, {@code copy()}, {@code jump()}, and {@code defaultJumpDistance()}.
- * Default implementations are provided for all other methods.
- *
- * <p>Objects that implement {@code java.util.JumpableRng} are
- * typically not cryptographically secure. Consider instead using
- * {@link java.security.SecureRandom} to get a cryptographically
- * secure pseudo-random number generator for use by
- * security-sensitive applications.
- *
- * @author Guy Steele
- * @since 1.9
- */
-public interface JumpableRng extends StreamableRng {
- /**
- * Returns a new generator whose internal state is an exact copy
- * of this generator (therefore their future behavior should be
- * identical if subjected to the same series of operations).
- *
- * @return a new object that is a copy of this generator
- */
- JumpableRng copy();
-
- /**
- * Alter the state of this pseudorandom number generator so as to
- * jump forward a large, fixed distance (typically 2<sup>64</sup>
- * or more) within its state cycle.
- */
- void jump();
-
- /**
- * Returns the distance by which the {@code jump()} method will jump
- * forward within the state cycle of this generator object.
- *
- * @return the default jump distance (as a {@code double} value)
- */
- double defaultJumpDistance();
-
- /**
- * Returns an effectively unlimited stream of new pseudorandom
- * number generators, each of which implements the {@code Rng}
- * interface.
- *
- * @implNote It is permitted to implement this method in a manner
- * equivalent to {@code jumps(Long.MAX_VALUE)}.
- *
- * @implNote The default implementation produces a sequential stream
- * that repeatedly calls {@code copy()} and {@code jump()} on this generator,
- * and the copies become the generators produced by the stream.
- *
- * @return a stream of objects that implement the {@code Rng} interface
- */
- default Stream<Rng> jumps() {
- return Stream.generate(this::copyAndJump).sequential();
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number of
- * new pseudorandom number generators, each of which implements the
- * {@code Rng} interface.
- *
- * @implNote The default implementation produces a sequential stream
- * that repeatedly calls {@code copy()} and {@code jump()} on this generator,
- * and the copies become the generators produced by the stream.
- *
- * @param streamSize the number of generators to generate
- * @return a stream of objects that implement the {@code Rng} interface
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero
- */
- default Stream<Rng> jumps(long streamSize) {
- return jumps().limit(streamSize);
- }
-
- /**
- * Returns an effectively unlimited stream of new pseudorandom
- * number generators, each of which implements the {@code Rng}
- * interface. Ideally the generators in the stream will appear
- * to be statistically independent.
- *
- * @implNote The default implementation calls {@code jumps()}.
- *
- * @return a stream of objects that implement the {@code Rng} interface
- */
- default Stream<Rng> rngs() {
- return this.jumps();
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number of
- * new pseudorandom number generators, each of which implements the
- * {@code Rng} interface. Ideally the generators in the stream will
- * appear to be statistically independent.
- *
- * @implNote The default implementation calls {@code jumps(streamSize)}.
- *
- * @param streamSize the number of generators to generate
- * @return a stream of objects that implement the {@code Rng} interface
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero
- */
- default Stream<Rng> rngs(long streamSize) {
- return this.jumps(streamSize);
- }
-
- /**
- * Copy this generator, jump this generator forward, then return the copy.
- *
- * @return a copy of this generator object before the jump occurred
- */
- default Rng copyAndJump() {
- Rng result = copy();
- jump();
- return result;
- }
-
-}