Package org.apache.commons.rng.core.source32

Class XoShiRo128StarStar

java.lang.Object

org.apache.commons.rng.core.BaseProvider

org.apache.commons.rng.core.source32.IntProvider

org.apache.commons.rng.core.source32.XoShiRo128StarStar

All Implemented Interfaces:

RandomIntSource, org.apache.commons.rng.JumpableUniformRandomProvider, org.apache.commons.rng.LongJumpableUniformRandomProvider, org.apache.commons.rng.RestorableUniformRandomProvider, org.apache.commons.rng.UniformRandomProvider

public class XoShiRo128StarStar
extends IntProvider

A fast all-purpose 32-bit generator. For faster generation of float values try the XoShiRo128Plus generator.

This is a member of the Xor-Shift-Rotate family of generators. Memory footprint is 128 bits.

Since:

1.3

See Also:

Original source code, xorshiro / xoroshiro generators

Field Summary

Fields

Modifier and Type	Field	Description
protected int	state0	State 0 of the generator.
protected int	state1	State 1 of the generator.
protected int	state2	State 2 of the generator.
protected int	state3	State 3 of the generator.

Constructor Summary

Constructors

Modifier	Constructor	Description
	XoShiRo128StarStar(int[] seed)	Creates a new instance.
	XoShiRo128StarStar(int seed0, int seed1, int seed2, int seed3)	Creates a new instance using a 4 element seed.
protected	XoShiRo128StarStar(XoShiRo128StarStar source)	Creates a copy instance.

Method Summary

Modifier and Type	Method	Description
protected XoShiRo128StarStar	copy()	Create a copy.
protected byte[]	getStateInternal()	Creates a snapshot of the RNG state.
org.apache.commons.rng.UniformRandomProvider	jump()
org.apache.commons.rng.JumpableUniformRandomProvider	longJump()
int	next()	Return the next random value.
protected int	nextOutput()	Use the current state to compute the next output from the generator.
protected void	setStateInternal(byte[] s)	Resets the RNG to the given state.

Methods inherited from class org.apache.commons.rng.core.source32.IntProvider

nextBoolean, nextBytes, nextBytes, nextDouble, nextInt, nextLong, resetCachedState

Methods inherited from class org.apache.commons.rng.core.BaseProvider

checkIndex, checkStateSize, composeStateInternal, extendSeed, extendSeed, fillState, fillState, restoreState, saveState, splitStateInternal, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.commons.rng.JumpableUniformRandomProvider

jumps, jumps

Methods inherited from interface org.apache.commons.rng.LongJumpableUniformRandomProvider

longJumps, longJumps

Methods inherited from interface org.apache.commons.rng.UniformRandomProvider

doubles, doubles, doubles, doubles, ints, ints, ints, ints, longs, longs, longs, longs, nextBoolean, nextBytes, nextBytes, nextDouble, nextDouble, nextDouble, nextFloat, nextFloat, nextFloat, nextInt, nextInt, nextInt, nextLong, nextLong, nextLong

Field Detail

state0

protected int state0

State 0 of the generator.

state1

protected int state1

State 1 of the generator.

state2

protected int state2

State 2 of the generator.

state3

protected int state3

State 3 of the generator.

Constructor Detail

XoShiRo128StarStar

public XoShiRo128StarStar(int[] seed)

Creates a new instance.

Parameters:

seed - Initial seed. If the length is larger than 4, only the first 4 elements will be used; if smaller, the remaining elements will be automatically set. A seed containing all zeros will create a non-functional generator.

XoShiRo128StarStar

public XoShiRo128StarStar(int seed0,
                          int seed1,
                          int seed2,
                          int seed3)

Creates a new instance using a 4 element seed. A seed containing all zeros will create a non-functional generator.

Parameters:

seed0 - Initial seed element 0.

seed1 - Initial seed element 1.

seed2 - Initial seed element 2.

seed3 - Initial seed element 3.

XoShiRo128StarStar

protected XoShiRo128StarStar(XoShiRo128StarStar source)

Creates a copy instance.

Parameters:

source - Source to copy.

Method Detail

nextOutput

protected int nextOutput()

Use the current state to compute the next output from the generator. The output function shall vary with respect to different generators. This method is called from RandomIntSource.next() before the current state is updated.

Returns:

the next output

copy

protected XoShiRo128StarStar copy()

Create a copy.

Returns:

the copy

getStateInternal

protected byte[] getStateInternal()

Creates a snapshot of the RNG state.

Overrides:

getStateInternal in class IntProvider

Returns:

the internal state.

setStateInternal

protected void setStateInternal(byte[] s)

Resets the RNG to the given state.

Overrides:

setStateInternal in class IntProvider

Parameters:

s - State (previously obtained by a call to BaseProvider.getStateInternal()).

See Also:

BaseProvider.checkStateSize(byte[],int)

next

public int next()

Return the next random value.

Specified by:

next in interface RandomIntSource

Returns:

the next random value.

jump

public org.apache.commons.rng.UniformRandomProvider jump()

The jump size is the equivalent of 2⁶⁴ calls to nextInt(). It can provide up to 2⁶⁴ non-overlapping subsequences.

Specified by:

jump in interface org.apache.commons.rng.JumpableUniformRandomProvider

longJump

public org.apache.commons.rng.JumpableUniformRandomProvider longJump()

The jump size is the equivalent of 2⁹⁶ calls to nextLong(). It can provide up to 2³² non-overlapping subsequences of length 2⁹⁶; each subsequence can provide up to 2³² non-overlapping subsequences of length 2⁶⁴ using the JumpableUniformRandomProvider.jump() method.

Specified by:

longJump in interface org.apache.commons.rng.LongJumpableUniformRandomProvider