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Use a more safe variant of binary search for the GBA db.

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profi200 2024-03-24 14:29:29 +01:00
parent 2935efc1ad
commit 4be54ddead
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GPG Key ID: FD2BAB7782919B0A
1 changed files with 39 additions and 35 deletions
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74
source/arm11/save_type.c
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@ -135,47 +135,52 @@ u16 detectSaveType(const u32 romSize, const u16 defaultSave)
return saveType;
}
// Search for entry with first u64 of the SHA1 = x using binary search.
static Result searchGbaDb(const u64 x, GbaDbEntry *const db, s32 *const entryPos)
// Search for the entry with first u64 of the SHA1 = x using binary search.
// Note: Loading the whole db to memory first is still slower.
static Result searchGbaDb(const u64 x, GbaDbEntry *const db)
{
debug_printf("Database search: '%016" PRIX64 "'\n", __builtin_bswap64(x));
Result res;
FHandle f;
if((res = fOpen(&f, "gba_db.bin", FA_OPEN_EXISTING | FA_READ)) == RES_OK)
Result res = fOpen(&f, "gba_db.bin", FA_OPEN_EXISTING | FA_READ);
if(res != RES_OK) return res;
u32 l = 0;
u32 r = fSize(f) / sizeof(GbaDbEntry);
while(l < r)
{
s32 l = 0;
s32 r = fSize(f) / sizeof(GbaDbEntry) - 1; // TODO: Check for 0!
while(1)
const u32 m = l + (r - l) / 2;
//debug_printf("l: %" PRIu32 " m: %" PRIu32 " r: %" PRIu32 "\n", l, m, r);
res = fLseek(f, sizeof(GbaDbEntry) * m);
if(res != RES_OK)
{
const s32 mid = l + (r - l) / 2;
debug_printf("l: %ld r: %ld mid: %ld\n", l, r, mid);
if((res = fLseek(f, sizeof(GbaDbEntry) * mid)) != RES_OK) break;
if((res = fRead(f, db, sizeof(GbaDbEntry), NULL)) != RES_OK) break;
u64 tmp;
memcpy(&tmp, db->sha1, 8);
if(tmp == x)
{
*entryPos = mid; // TODO: Remove.
break;
}
if(r <= l)
{
debug_printf("Not found!\n");
res = RES_NOT_FOUND;
break;
}
if(tmp > x) r = mid - 1;
else l = mid + 1;
fClose(f);
return res;
}
res = fRead(f, db, sizeof(GbaDbEntry), NULL);
if(res != RES_OK)
{
fClose(f);
return res;
}
fClose(f);
u64 tmp;
memcpy(&tmp, db->sha1, 8);
if(x > tmp)
{
l = m + 1;
}
else if(x < tmp)
{
r = m;
}
else
{
fClose(f);
return RES_OK;
}
}
return res;
return RES_NOT_FOUND;
}
u16 getSaveType(const OafConfig *const cfg, const u32 romSize, const char *const savePath)
@ -190,9 +195,8 @@ u16 getSaveType(const OafConfig *const cfg, const u32 romSize, const char *const
Result res;
GbaDbEntry dbEntry;
s32 dbPos = -1;
u16 saveType = SAVE_TYPE_NONE;
res = searchGbaDb(*sha1, &dbEntry, &dbPos);
res = searchGbaDb(*sha1, &dbEntry);
if(res == RES_OK) saveType = dbEntry.attr & 0xFu;
else if(!saveOverride && res == RES_NOT_FOUND) return autoSaveType;
else if(res != RES_NOT_FOUND)