hash.h File Reference

#include "board.h"
#include "settings.h"
#include "util.h"
#include "stats.h"
#include <stdbool.h>
#include <stdio.h>

Go to the source code of this file.

Classes
struct	HashData
struct	Hash
struct	HashLock
struct	HashTable

Typedefs
typedef struct HashData	HashData
typedef struct Hash	Hash
typedef struct HashLock	HashLock
typedef struct HashTable	HashTable

Functions
void	hash_code_init (void)
	Initialize global hash code data. More...
void	hash_move_init (void)
	Initialize global hash move data. More...
void	hash_init (HashTable *, const unsigned long long)
	Initialise the hashtable. More...
void	hash_cleanup (HashTable *)
	Clear the hashtable. More...
void	hash_clear (HashTable *)
	Clear the hashtable. More...
void	hash_free (HashTable *)
	Free the hashtable. More...
void	hash_store (HashTable *, const Board *, const unsigned long long, const int, const int, const int, const int, const int, const int, const int)
	Store an hashtable item. More...
void	hash_force (HashTable *, const Board *, const unsigned long long, const int, const int, const int, const int, const int, const int, const int)
	Store an hashtable item. More...
bool	hash_get (HashTable *, const Board *, const unsigned long long, HashData *)
	Find an hash table entry according to the evaluated board hash codes. More...
void	hash_copy (const HashTable *, HashTable *)
	Copy an hastable to another one. More...
void	hash_print (const HashData *, FILE *)
	print HashData content. More...
void	hash_feed (HashTable *, const Board *, const unsigned long long, const int, const int, const int, const int, const int)
	feed hash table (from Cassio). More...
void	hash_exclude_move (HashTable *, const Board *, const unsigned long long, const int)
unsigned int	writeable_level (HashData *data)
	make a level from date, cost, depth & selectivity. More...

Variables
const HashData	HASH_DATA_INIT
unsigned long long	hash_rank [16][256]
unsigned long long	hash_move [64][60]

Detailed Description

Hash table's header.

Date

1998 - 2017

Author

Richard Delorme

Version

4.4

Typedef Documentation

Hash

typedef struct Hash Hash

Hash : item stored in the hash table

HashData

typedef struct HashData HashData

HashData : data stored in the hash table

HashLock

typedef struct HashLock HashLock

HashLock : lock for table entries

HashTable

typedef struct HashTable HashTable

HashTable: position storage

Function Documentation

hash_cleanup()

void hash_cleanup

(

HashTable *

hash_table

)

Clear the hashtable.

Set all hash table entries to zero.

Parameters

hash_table

Hash table to clear.

hash_clear()

void hash_clear

(

HashTable *

hash_table

)

Clear the hashtable.

Change the date of the hash table.

Parameters

hash_table

Hash table to clear.

hash_code_init()

void hash_code_init

(

void

)

Initialize global hash code data.

hash_copy()

void hash_copy	(	const HashTable *	src,
		HashTable *	dest
	)

Copy an hastable to another one.

Parameters

src	Source hash table to copy.
dest	Destination hash table.

hash_exclude_move()

void hash_exclude_move	(	HashTable *	,
		const Board *	,
		const unsigned long	long,
		const int
	)

hash_feed()

void hash_feed	(	HashTable *	hash_table,
		const Board *	board,
		const unsigned long long	hash_code,
		const int	depth,
		const int	selectivity,
		const int	lower,
		const int	upper,
		const int	move
	)

feed hash table (from Cassio).

Parameters

hash_table	Hash Table.
hash_code	Hash code.
depth	Search depth.
selectivity	Selectivity level.
lower	Alpha bound.
upper	Beta bound.
move	best move.

hash_force()

void hash_force	(	HashTable *	hash_table,
		const Board *	board,
		const unsigned long long	hash_code,
		const int	depth,
		const int	selectivity,
		const int	cost,
		const int	alpha,
		const int	beta,
		const int	score,
		const int	move
	)

Store an hashtable item.

Does the same as hash_store() except it always store the current search state

Parameters

hash_table	Hash table to update.
hash_code	Hash code of an othello board.
alpha	Alpha bound when calling the alphabeta function.
depth	Search depth.
selectivity	Search selectivity.
cost	Search cost (i.e. log2(node count)).
beta	Beta bound when calling the alphabeta function.
score	Best score found.
move	Best move found.

hash_free()

void hash_free

(

HashTable *

hash_table

)

Free the hashtable.

Free the memory allocated by the hash table entries

Parameters

hash_table

hash_table to free.

hash_get()

bool hash_get	(	HashTable *	hash_table,
		const Board *	board,
		const unsigned long long	hash_code,
		HashData *	data
	)

Find an hash table entry according to the evaluated board hash codes.

Parameters

hash_table	Hash table.
hash_code	Hash code of an othello board.
data	Output hash data.

Returns

True the board was found, false otherwise.

Erase an hash table entry.

Parameters

hash_table	Hash table.
hash_code	Hash code of an othello board.
move	Move to exclude.

Copy an hastable to another one.

Parameters

src	Source hash table to copy.
dest	Destination hash table.

print HashData content.

Parameters

data	Hash Data
f	Output stream

hash_init()

void hash_init	(	HashTable *	hash_table,
		const unsigned long long	size
	)

Initialise the hashtable.

Allocate the hash table entries and initialise the hash masks.

Parameters

hash_table	Hash table to setup.
size	Requested size for the hash table in number of entries.

hash_move_init()

void hash_move_init

(

void

)

Initialize global hash move data.

hash_print()

void hash_print	(	const HashData *	data,
		FILE *	f
	)

print HashData content.

Parameters

data	Hash Data
f	Output stream

hash_store()

void hash_store	(	HashTable *	hash_table,
		const Board *	board,
		const unsigned long long	hash_code,
		const int	depth,
		const int	selectivity,
		const int	cost,
		const int	alpha,
		const int	beta,
		const int	score,
		const int	move
	)

Store an hashtable item.

Find an hash table entry according to the evaluated board hash codes. Then update the entry if it already exists otherwise create a new one. Collisions are managed in such a way that better existing entries are always preserved and the new evaluated data is always added. Lower and upper score bounds are then updated/set from the alpha, beta and score values according to the following alphabeta property (where alpha < beta): -if (score >= beta) score is a lower bound of the real score -if (score <= alpha) score is an upper bound of the real score -if (alpha < score && score < beta) score equals the real score So: -if (score < beta) update the upper bound of the hash entry -if (score > alpha) update the lower bound of the hash entry The best move is also stored, but only if score >= alpha. In case the entry already exists with better data, nothing is stored.

Parameters

hash_table	Hash table to update.
hash_code	Hash code of an othello board.
alpha	Alpha bound when calling the alphabeta function.
depth	Search depth.
selectivity	Search selectivity.
cost	Search cost (i.e. log2(node count)).
beta	Beta bound when calling the alphabeta function.
score	Best score found.
move	Best move found.

writeable_level()

unsigned int writeable_level ( HashData *  data )

inline

make a level from date, cost, depth & selectivity.

Parameters

data	Hash data.

Returns

A level.

Variable Documentation

HASH_DATA_INIT

const HashData HASH_DATA_INIT

HashData init value

hash_move

unsigned long long hash_move[64][60]

hashing global data

hash_rank

unsigned long long hash_rank[16][256]

hashing global data