124 lines
2.6 KiB
C
124 lines
2.6 KiB
C
/* hist.c - history management.
|
|
*
|
|
* Copyright (C) 2024 Bruno Raoult ("br")
|
|
* Licensed under the GNU General Public License v3.0 or later.
|
|
* Some rights reserved. See COPYING.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along with this
|
|
* program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
|
|
*
|
|
* SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
|
|
*
|
|
*/
|
|
|
|
#include <brlib.h>
|
|
#include <bug.h>
|
|
|
|
#include "position.h"
|
|
#include "hash.h"
|
|
#include "move.h"
|
|
#include "hist.h"
|
|
|
|
hist_t hist = {
|
|
.nstates = 1,
|
|
{ { .move = MOVE_NO_MOVE, .key = U64(0), .prev = &hist.state[0] } },
|
|
};
|
|
|
|
/**
|
|
* hist_init() - initialize history states data.
|
|
*
|
|
* This should be done every time a new position must be handled.
|
|
*/
|
|
void hist_init(void)
|
|
{
|
|
hist.nstates = 1;
|
|
hist.state[0].key = U64(0);
|
|
hist.state[0].move = MOVE_NO_MOVE;
|
|
hist.state[0].prev = &hist.state[0];
|
|
}
|
|
|
|
/**
|
|
* hist_push() - add a state and move to hist
|
|
* @st: &state_t to add
|
|
* @move: &move_t to add in @st
|
|
*/
|
|
void hist_push(state_t *st, move_t *move)
|
|
{
|
|
int last = hist.nstates++;
|
|
|
|
bug_on(last >= HIST_SIZE);
|
|
hist.state[last] = *st;
|
|
hist.state[last].prev = &hist.state[last - 1];
|
|
hist.state[last].move = *move;
|
|
}
|
|
|
|
/**
|
|
* hist_pop() - return last state from hist entry, and remove it from list
|
|
*
|
|
* Not used, only for debug.
|
|
*/
|
|
state_t *hist_pop(void)
|
|
{
|
|
return hist.state + --hist.nstates;
|
|
}
|
|
|
|
/**
|
|
* hist_last() - return last state from hist.
|
|
*/
|
|
state_t *hist_last(void)
|
|
{
|
|
return hist.state + hist.nstates - 1;
|
|
}
|
|
|
|
/**
|
|
* hist_prev() - return a state's ancestor.
|
|
* @st: &state_t state
|
|
*
|
|
* No test is done on ancestor. Caller should check it is different
|
|
* from HIST_START.
|
|
*/
|
|
state_t *hist_prev(state_t *st)
|
|
{
|
|
return st->prev;
|
|
}
|
|
|
|
/**
|
|
* hist_prev2() - return a state's second ancestor.
|
|
* @st: &state_t state
|
|
*
|
|
* No test is done on ancestors. Caller should check it is different
|
|
* from HIST_START.
|
|
*/
|
|
state_t *hist_prev2(state_t *st)
|
|
{
|
|
return st->prev->prev;
|
|
}
|
|
|
|
/**
|
|
* hist_prev4() - return a state's 4th ancestor.
|
|
* @st: &state_t state
|
|
*
|
|
* No test is done on ancestors. Caller should check it is different
|
|
* from HIST_START.
|
|
*/
|
|
state_t *hist_prev4(state_t *st)
|
|
{
|
|
return st->prev->prev->prev->prev;
|
|
}
|
|
|
|
/**
|
|
* hist_print() - print hist entries
|
|
*/
|
|
void hist_static_print(void)
|
|
{
|
|
char movestr[8];
|
|
|
|
printf("rev history: ");
|
|
for (state_t *p = hist_last(); p != HIST_START; p = hist_prev(p)) {
|
|
printf("%s(%lx) ",
|
|
p->move == MOVE_NO_MOVE? "none": move_to_str(movestr, p->move, 0),
|
|
hash_short(p->key));
|
|
}
|
|
printf("\n");
|
|
}
|