Package io.github.pr0methean.betterrandom.seed

Class SeedGeneratorPreferenceList

java.lang.Object

java.util.concurrent.CopyOnWriteArrayList<SeedGenerator>

io.github.pr0methean.betterrandom.seed.SeedGeneratorPreferenceList

All Implemented Interfaces:

SeedGenerator, Serializable, Cloneable, Iterable<SeedGenerator>, Collection<SeedGenerator>, List<SeedGenerator>, RandomAccess

public class SeedGeneratorPreferenceList
extends CopyOnWriteArrayList<SeedGenerator>
implements SeedGenerator

A SeedGenerator implementation that iterates over multiple delegates until one succeeds.

See Also:

Serialized Form

Field Summary

Fields inherited from interface io.github.pr0methean.betterrandom.seed.SeedGenerator

EMPTY_SEED

Constructor Summary

Constructors

Constructor	Description
SeedGeneratorPreferenceList(boolean isAlwaysWorthTrying, SeedGenerator... contents)	Creates an instance.
SeedGeneratorPreferenceList(Collection<? extends SeedGenerator> contents, boolean isAlwaysWorthTrying)	Creates an instance.

Method Summary

Modifier and Type	Method	Description
void	generateSeed(byte[] output)	Generates a seed value for a random number generator in an existing array.
byte[]	generateSeed(int length)	Generates and returns a seed value for a random number generator as a new array.
boolean	isWorthTrying()	Returns true if we cannot determine quickly (i.e.

Methods inherited from class java.util.concurrent.CopyOnWriteArrayList

add, add, addAll, addAll, addAllAbsent, addIfAbsent, clear, clone, contains, containsAll, equals, forEach, get, hashCode, indexOf, indexOf, isEmpty, iterator, lastIndexOf, lastIndexOf, listIterator, listIterator, remove, remove, removeAll, removeIf, replaceAll, retainAll, set, size, sort, spliterator, subList, toArray, toArray, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

parallelStream, stream, toArray

Constructor Detail

SeedGeneratorPreferenceList

public SeedGeneratorPreferenceList(Collection<? extends SeedGenerator> contents,
                                   boolean isAlwaysWorthTrying)

Creates an instance.

Parameters:

contents - the initial list of delegates, in the order they will be tried until one succeeds

isAlwaysWorthTrying - true if isWorthTrying() should always return true rather than delegating

SeedGeneratorPreferenceList

public SeedGeneratorPreferenceList(boolean isAlwaysWorthTrying,
                                   SeedGenerator... contents)

Creates an instance.

Parameters:

contents - the initial delegates, in the order they will be tried until one succeeds

isAlwaysWorthTrying - true if isWorthTrying() should always return true rather than delegating

Method Detail

generateSeed

public void generateSeed(byte[] output)
                  throws SeedException

Description copied from interface: SeedGenerator

Generates a seed value for a random number generator in an existing array.

Specified by:

generateSeed in interface SeedGenerator

Parameters:

output - The array that is to be populated with the seed.

Throws:

SeedException - If a seed cannot be generated for any reason.

generateSeed

public byte[] generateSeed(int length)
                    throws SeedException

Description copied from interface: SeedGenerator

Generates and returns a seed value for a random number generator as a new array.

Specified by:

generateSeed in interface SeedGenerator

Parameters:

length - The length of the seed to generate (in bytes).

Returns:

A byte array containing the seed data.

Throws:

SeedException - If a seed cannot be generated for any reason.

isWorthTrying

public boolean isWorthTrying()

Description copied from interface: SeedGenerator

Returns true if we cannot determine quickly (i.e. without I/O calls) that this SeedGenerator would throw a SeedException if SeedGenerator.generateSeed(int) or SeedGenerator.generateSeed(byte[]) were being called right now.

Specified by:

isWorthTrying in interface SeedGenerator

Returns:

true if this SeedGenerator will get as far as an I/O call or other slow operation in attempting to generate a seed immediately.