net.viktorc.detroid.framework.engine

Class EndGameTableBase

Object

EndGameTableBase

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

GaviotaTableBaseJNI

public abstract class EndGameTableBase
extends Object
implements Closeable

An abstract class for chess endgame tablebases. As there is no Java EGTB, it assumes the probing library to be a native shared library.

Author:

Viktor

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	EndGameTableBase.DTM A class containing the outcome of a position in an endgame tablebase and potentially the distance to mate from the position.
static class	EndGameTableBase.EGTBStats A simple container class for basic endgame tablebase probing stats.
static class	EndGameTableBase.WDL A simple enum for possible outcomes for positions in endgame tablebases.

Field Summary

Fields

Modifier and Type	Field and Description
static int	MAX_NUMBER_OF_PIECES The maximum number of pieces on the board for which there are endgame tablebases.

Constructor Summary

Constructors

Constructor and Description
EndGameTableBase()

Method Summary

Modifier and Type	Method and Description
abstract boolean	areTableBasesAvailable(int piecesOnBoard) It returns whether there are at least some tablebase files loaded for positions with the given number of pieces on the board.
abstract void	clearCache() Flushes the probing cache.
abstract EndGameTableBase.EGTBStats	getStats() Returns some basic usage stats about the endgame tablebase.
abstract void	init(String path, long cacheSize, Object... args) Initializes the probing code, potentially including the setting up of the cache.
abstract boolean	isInit() Returns whether the probing code has been initialized.
boolean	isProbingLibLoaded() Whether the last call to loadProbingLibrary(String) resulted in the successful loading of the library.
void	loadProbingLibrary(String path) Loads the probing library at the given path.
abstract EndGameTableBase.DTM	probeDTM(Position pos, boolean soft) It probes for the given position and if found, it returns whether it is a win, loss, or draw; and in case it is a win or loss, it also returns the distance to mate.
abstract EndGameTableBase.WDL	probeWDL(Position pos, boolean soft) It probes for the given position and if found, it returns whether it is a winning position, a losing position, or a draw; else it returns null.
abstract void	resetStats() Resets the endgame tablebase stats.

Methods inherited from class Object

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

Methods inherited from interface Closeable

close

Field Detail

MAX_NUMBER_OF_PIECES

public static final int MAX_NUMBER_OF_PIECES

The maximum number of pieces on the board for which there are endgame tablebases.

See Also:

Constant Field Values

Constructor Detail

EndGameTableBase

public EndGameTableBase()

Method Detail

loadProbingLibrary

public void loadProbingLibrary(String path)

Loads the probing library at the given path.

Parameters:

path - The path to the shared library containing the probing code.

isProbingLibLoaded

public boolean isProbingLibLoaded()

Whether the last call to loadProbingLibrary(String) resulted in the successful loading of the library.

Returns:

Whether the last library loading attempt has been successful.

init

public abstract void init(String path,
                          long cacheSize,
                          Object... args)

Initializes the probing code, potentially including the setting up of the cache.

Parameters:

path - The path to the folders containing the endgame tablebase files.

cacheSize - The size of the probing cache in bytes.

args - Optional arguments.

isInit

public abstract boolean isInit()

Returns whether the probing code has been initialized.

Returns:

Whether the probing code has been initialized.

clearCache

public abstract void clearCache()

Flushes the probing cache.

areTableBasesAvailable

public abstract boolean areTableBasesAvailable(int piecesOnBoard)

It returns whether there are at least some tablebase files loaded for positions with the given number of pieces on the board.

Parameters:

piecesOnBoard - The total number of pieces on the board.

Returns:

If there are tablebases loaded for the specified number of men on the board.

getStats

public abstract EndGameTableBase.EGTBStats getStats()

Returns some basic usage stats about the endgame tablebase.

Returns:

Endgame tablebase stats.

resetStats

public abstract void resetStats()

Resets the endgame tablebase stats.

probeWDL

public abstract EndGameTableBase.WDL probeWDL(Position pos,
                                              boolean soft)

It probes for the given position and if found, it returns whether it is a winning position, a losing position, or a draw; else it returns null.

Parameters:

pos - The chess position to look for.

soft - Whether only the cache should be probed.

Returns:

Whether it is a winning position, a losing position, or a draw.

probeDTM

public abstract EndGameTableBase.DTM probeDTM(Position pos,
                                              boolean soft)

It probes for the given position and if found, it returns whether it is a win, loss, or draw; and in case it is a win or loss, it also returns the distance to mate. If the position is not found, it returns null.

Parameters:

pos - The chess position to look for.

soft - Whether only the cache should be probed.

Returns:

Whether it is a win, loss, or draw; and potentially the distance to mate.