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remove caching from is_guarded, which should slow it down significantly :-(

This commit is contained in:
Enno Rehling 2015-11-21 21:33:17 +01:00
parent 7dae5aa035
commit 6b83120c7a
1 changed files with 3 additions and 52 deletions
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55
src/move.c
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@ -938,77 +938,28 @@ bool is_guard(const struct unit * u, unsigned int mask)
return is_guardian_r(u) && (getguard(u) & mask) != 0; return is_guardian_r(u) && (getguard(u) & mask) != 0;
} }
#define MAXGUARDCACHE 16
/** returns the guard which prevents 'u' from doing 'mask' actions in 'r'.
*/
unit *is_guarded(region * r, unit * u, unsigned int mask) unit *is_guarded(region * r, unit * u, unsigned int mask)
{ {
unit *u2 = NULL; unit *u2;
int i, noguards = 1; int noguards = 1;
static unit *guardcache[MAXGUARDCACHE], *lastguard; /* STATIC_XCALL: used across calls */
static int gamecookie = -1;
if (!fval(r, RF_GUARDED)) { if (!fval(r, RF_GUARDED)) {
return NULL; return NULL;
} }
if (gamecookie != global.cookie) {
if (gamecookie >= 0) {
/* clear the previous turn's cache */
memset(guardcache, 0, sizeof(guardcache));
lastguard = NULL;
}
gamecookie = global.cookie;
}
if (lastguard && lastguard->region == r) {
if (is_guardian_u(lastguard, u, mask)) {
return lastguard;
}
}
for (i = 0; i != MAXGUARDCACHE; ++i) {
unit *guard = guardcache[i];
if (guard && guard != lastguard && guard->region == r) {
noguards = 0;
if (is_guardian_u(guard, u, mask)) {
lastguard = guard;
return guard;
}
if (u2 == guard) {
/* same guard twice signals we've tested everyone */
return NULL;
}
u2 = guard;
}
else {
/* exhausted all the guards in the cache, but maybe we'll find one later? */
break;
}
}
/* at this point, u2 is the last unit we tested to /* at this point, u2 is the last unit we tested to
* be a guard (and failed), or NULL * be a guard (and failed), or NULL
* i is the position of the first free slot in the cache */ * i is the position of the first free slot in the cache */
for (u2 = (u2 ? u2->next : r->units); u2; u2 = u2->next) { for (u2 = r->units; u2; u2 = u2->next) {
if (is_guardian_r(u2)) { if (is_guardian_r(u2)) {
noguards = 0; noguards = 0;
/* u2 is a guard, so worth remembering */
if (i < MAXGUARDCACHE)
guardcache[i++] = u2;
if (is_guardian_u(u2, u, mask)) { if (is_guardian_u(u2, u, mask)) {
/* u2 is our guard. stop processing (we might have to go further next time) */ /* u2 is our guard. stop processing (we might have to go further next time) */
lastguard = u2;
return u2; return u2;
} }
} }
} }
/* there are no more guards. we signal this by duplicating the last one.
* i is still the position of the first free slot in the cache */
if (i > 0 && i < MAXGUARDCACHE) {
guardcache[i] = guardcache[i - 1];
}
if (noguards) { if (noguards) {
/* you are mistaken, sir. there are no guards in these lands */ /* you are mistaken, sir. there are no guards in these lands */