nxt.addons

Class ReproducibleRandomness

java.lang.Object

nxt.addons.ReproducibleRandomness

All Implemented Interfaces:

RandomnessSource

public class ReproducibleRandomness
extends java.lang.Object
implements RandomnessSource

The purpose of this class is to make sure all contract runners will generate the same random numbers given the same random seed. Unfortunately, the default SecureRandom implementation in Java 9+ does not respect this property i.e. given the same random seed even two different secure random objects in the same process will generate different numbers. The java.util.Random implementation is reproducible, but is trivial to predict. We therefore rely on the "SHA1PRNG" algorithm (Java 8 default) which is reproducible and provides reasonable level of security and interoperability between Java versions. This class delegates all random number requests to the actual secure random.

Constructor Summary

Constructors

Constructor and Description
ReproducibleRandomness()

Method Summary

Modifier and Type	Method and Description
java.util.stream.DoubleStream	doubles()
java.util.stream.DoubleStream	doubles(double randomNumberOrigin, double randomNumberBound)
java.util.stream.DoubleStream	doubles(long streamSize)
java.util.stream.DoubleStream	doubles(long streamSize, double randomNumberOrigin, double randomNumberBound)
long	getSeed()
java.util.stream.IntStream	ints()
java.util.stream.IntStream	ints(int randomNumberOrigin, int randomNumberBound)
java.util.stream.IntStream	ints(long streamSize)
java.util.stream.IntStream	ints(long streamSize, int randomNumberOrigin, int randomNumberBound)
java.util.stream.LongStream	longs()
java.util.stream.LongStream	longs(long streamSize)
java.util.stream.LongStream	longs(long randomNumberOrigin, long randomNumberBound)
java.util.stream.LongStream	longs(long streamSize, long randomNumberOrigin, long randomNumberBound)
boolean	nextBoolean()
void	nextBytes(byte[] bytes)
double	nextDouble()
float	nextFloat()
int	nextInt()
int	nextInt(int bound)
long	nextLong()
void	setSeed(long seed)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ReproducibleRandomness

public ReproducibleRandomness()

Method Detail

setSeed

public void setSeed(long seed)

Specified by:

setSeed in interface RandomnessSource

getSeed

public long getSeed()

Specified by:

getSeed in interface RandomnessSource

nextBytes

public void nextBytes(byte[] bytes)

Specified by:

nextBytes in interface RandomnessSource

nextInt

public int nextInt()

Specified by:

nextInt in interface RandomnessSource

nextInt

public int nextInt(int bound)

Specified by:

nextInt in interface RandomnessSource

nextLong

public long nextLong()

Specified by:

nextLong in interface RandomnessSource

nextBoolean

public boolean nextBoolean()

Specified by:

nextBoolean in interface RandomnessSource

nextFloat

public float nextFloat()

Specified by:

nextFloat in interface RandomnessSource

nextDouble

public double nextDouble()

Specified by:

nextDouble in interface RandomnessSource

ints

public java.util.stream.IntStream ints(long streamSize)

Specified by:

ints in interface RandomnessSource

ints

public java.util.stream.IntStream ints()

Specified by:

ints in interface RandomnessSource

ints

public java.util.stream.IntStream ints(long streamSize,
                                       int randomNumberOrigin,
                                       int randomNumberBound)

Specified by:

ints in interface RandomnessSource

ints

public java.util.stream.IntStream ints(int randomNumberOrigin,
                                       int randomNumberBound)

Specified by:

ints in interface RandomnessSource

longs

public java.util.stream.LongStream longs(long streamSize)

Specified by:

longs in interface RandomnessSource

longs

public java.util.stream.LongStream longs()

Specified by:

longs in interface RandomnessSource

longs

public java.util.stream.LongStream longs(long streamSize,
                                         long randomNumberOrigin,
                                         long randomNumberBound)

Specified by:

longs in interface RandomnessSource

longs

public java.util.stream.LongStream longs(long randomNumberOrigin,
                                         long randomNumberBound)

Specified by:

longs in interface RandomnessSource

doubles

public java.util.stream.DoubleStream doubles(long streamSize)

Specified by:

doubles in interface RandomnessSource

doubles

public java.util.stream.DoubleStream doubles()

Specified by:

doubles in interface RandomnessSource

doubles

public java.util.stream.DoubleStream doubles(long streamSize,
                                             double randomNumberOrigin,
                                             double randomNumberBound)

Specified by:

doubles in interface RandomnessSource

doubles

public java.util.stream.DoubleStream doubles(double randomNumberOrigin,
                                             double randomNumberBound)

Specified by:

doubles in interface RandomnessSource