OpeningBook Class Reference

A collection of opening moves for chess. More...

#include <openingbook.h>

Inheritance diagram for OpeningBook:

Classes
struct	Entry
	An entry in the opening book. More...

Public Types
enum	AccessMode { Ram, Disk }

Public Member Functions
QList< Entry >	entries (quint64 key) const
int	import (const PgnGame &pgn, int maxMoves)
int	import (PgnStream &in, int maxMoves)
Chess::GenericMove	move (quint64 key) const
	OpeningBook (AccessMode mode=Ram)
bool	read (const QString &filename)
bool	write (const QString &filename) const
virtual	~OpeningBook ()

Protected Types
typedef QMultiMap< quint64, Entry >	Map

Protected Member Functions
void	addEntry (const Entry &entry, quint64 key)
virtual int	entrySize () const =0
virtual Entry	readEntry (QDataStream &in, quint64 *key) const =0
virtual void	writeEntry (const Map::const_iterator &it, QDataStream &out) const =0

Friends
LIB_EXPORT QDataStream &	operator<< (QDataStream &out, const OpeningBook *book)
LIB_EXPORT QDataStream &	operator>> (QDataStream &in, OpeningBook *book)

Detailed Description

A collection of opening moves for chess.

OpeningBook is a container (binary tree) class for opening moves that can be played by the GUI. When the game goes "out of book", control of the game is transferred to the players.

The opening book can be stored externally in a binary file. When it's needed, it is loaded in memory, and positions can be found quickly by searching the book for Zobrist keys that match the current board position.

Member Typedef Documentation

typedef QMultiMap<quint64, Entry> OpeningBook::Map

protected

The type of binary tree.

Member Enumeration Documentation

enum OpeningBook::AccessMode

AccessMode defines how a book is accessed during play.

Enumerator
Ram	Load the entire book to RAM.
Disk	Read moves directly from disk.

Constructor & Destructor Documentation

OpeningBook::OpeningBook

(

AccessMode

mode = Ram

)

Creates a new OpeningBook with access mode mode.

OpeningBook::~OpeningBook ( )

virtual

Destroys the opening book.

Member Function Documentation

void OpeningBook::addEntry ( const Entry &  entry, quint64  key  )

protected

Adds a new entry to the book.

QList< OpeningBook::Entry > OpeningBook::entries

(

quint64

key

)

const

Returns all entries matching key.

virtual int OpeningBook::entrySize ( ) const

protectedpure virtual

Returns the book format's internal entry size in bytes.

Implemented in PolyglotBook.

int OpeningBook::import	(	const PgnGame &	pgn,
		int	maxMoves
	)

Imports a PGN game.

Parameters

pgn	The game to import.
maxMoves	The maximum number of halfmoves that can be imported.

Returns the number of moves imported.

int OpeningBook::import	(	PgnStream &	in,
		int	maxMoves
	)

Imports PGN games from a stream.

Parameters

in	The PGN stream that contains the games.
maxMoves	The maximum number of halfmoves per game that can be imported.

Returns the number of moves imported.

Chess::GenericMove OpeningBook::move

(

quint64

key

)

const

Returns a move that can be played in a position where the Zobrist key is key.

If no matching moves are found, an empty (illegal) move is returned.

If there are multiple matches, a random, weighted move is returned. Popular moves have a higher probablity of being selected than unpopular ones.

bool OpeningBook::read

(

const QString &

filename

)

Reads a book from filename. Returns true if successful; otherwise returns false.

virtual Entry OpeningBook::readEntry ( QDataStream &  in, quint64 *  key  ) const

protectedpure virtual

Reads a new book entry from in and returns it.

The implementation must set key to the hash that belongs to the entry.

Implemented in PolyglotBook.

bool OpeningBook::write

(

const QString &

filename

)

const

Writes the book to filename. Returns true if successful; otherwise returns false.

virtual void OpeningBook::writeEntry ( const Map::const_iterator &  it, QDataStream &  out  ) const

protectedpure virtual

Writes the key and entry pointed to by it, to out.

Implemented in PolyglotBook.

Friends And Related Function Documentation

LIB_EXPORT QDataStream& operator<< ( QDataStream &  out, const OpeningBook *  book  )

friend

Writes a book to a data stream.

Warning

Do not write multiple OpeningBook objects to the same data stream, because the books are likely to have duplicate entries.

LIB_EXPORT QDataStream& operator>> ( QDataStream &  in, OpeningBook *  book  )

friend

Reads a book from a data stream.

Note

Multiple book files can be appended to the same OpeningBook object.

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The documentation for this class was generated from the following files:

• projects/lib/src/openingbook.h
• projects/lib/src/openingbook.cpp