Class LongProvider

java.lang.Object

org.apache.commons.rng.core.BaseProvider

org.apache.commons.rng.core.source64.LongProvider

All Implemented Interfaces:

RandomLongSource, RestorableUniformRandomProvider, UniformRandomProvider

Direct Known Subclasses:

AbstractL128, AbstractL64, AbstractXoRoShiRo1024, AbstractXoRoShiRo128, AbstractXoShiRo256, AbstractXoShiRo512, DotyHumphreySmallFastCounting64, JenkinsSmallFast64, MersenneTwister64, PcgRxsMXs64, SplitMix64, TwoCmres, XorShift1024Star

public abstract class LongProvider
extends BaseProvider
implements RandomLongSource

Base class for all implementations that provide a long-based source randomness.

Field Summary

Fields

Modifier and Type	Field	Description
private long	booleanSource	Provides a bit source for booleans.
private static final long	EMPTY_BOOL_SOURCE	Empty boolean source.
private static final long	EMPTY_INT_SOURCE	Empty int source.
private long	intSource	Provides a source for ints.

Constructor Summary

Constructors

Modifier	Constructor	Description
	LongProvider()	Creates a new instance.
protected	LongProvider(LongProvider source)	Creates a new instance copying the state from the source.

Method Summary

Modifier and Type	Method	Description
protected byte[]	getStateInternal()	Creates a snapshot of the RNG state.
boolean	nextBoolean()	Generates a boolean value.
int	nextInt()	Generates an int value.
long	nextLong()	Generates a long value.
protected void	resetCachedState()	Reset the cached state used in the default implementation of nextBoolean() and nextInt().
protected void	setStateInternal(byte[] s)	Resets the RNG to the given state.

Methods inherited from class BaseProvider

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

Methods inherited from class Object

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

Methods inherited from interface RandomLongSource

next

Methods inherited from interface UniformRandomProvider

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

Field Details

EMPTY_BOOL_SOURCE

private static final long EMPTY_BOOL_SOURCE

Empty boolean source. This is the location of the sign-bit after 63 right shifts on the boolean source.

See Also:

• Constant Field Values

EMPTY_INT_SOURCE

private static final long EMPTY_INT_SOURCE

Empty int source. This requires a negative value as the sign-bit is used to trigger a refill.

See Also:

• Constant Field Values

booleanSource

private long booleanSource

Provides a bit source for booleans.

A cached value from a call to RandomLongSource.next().

Only stores 63-bits when full as 1 bit has already been consumed. The sign bit is a flag that shifts down so the source eventually equals 1 when all bits are consumed and will trigger a refill.

intSource

private long intSource

Provides a source for ints.

A cached half-value value from a call to RandomLongSource.next(). The int is stored in the lower 32 bits with zeros in the upper bits. When empty this is set to negative to trigger a refill.

Constructor Details

LongProvider

public LongProvider()

Creates a new instance.

LongProvider

protected LongProvider(LongProvider source)

Creates a new instance copying the state from the source.

This provides base functionality to allow a generator to create a copy, for example for use in the JumpableUniformRandomProvider interface.

Parameters:

source - Source to copy.

Since:

1.3

Method Details

resetCachedState

protected void resetCachedState()

Reset the cached state used in the default implementation of nextBoolean() and nextInt().

This should be used when the state is no longer valid, for example after a jump performed for the JumpableUniformRandomProvider interface.

Since:

1.3

getStateInternal

protected byte[] getStateInternal()

Creates a snapshot of the RNG state.

Overrides:

getStateInternal in class BaseProvider

Returns:

the internal state.

setStateInternal

protected void setStateInternal(byte[] s)

Resets the RNG to the given state.

Overrides:

setStateInternal in class BaseProvider

Parameters:

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

See Also:

• BaseProvider.checkStateSize(byte[],int)

nextLong

public long nextLong()

Generates a long value.

Specified by:

nextLong in interface UniformRandomProvider

Returns:

the next random value.

nextInt

public int nextInt()

Generates an int value.

Specified by:

nextInt in interface UniformRandomProvider

Returns:

the next random value.

nextBoolean

public boolean nextBoolean()

Generates a boolean value.

Specified by:

nextBoolean in interface UniformRandomProvider

Returns:

the next random value.