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SyncHome/trunk/AVRProjects/sd2iec/src-1.0.0alpha0-98/src/p00cache.c
2023-03-13 09:01:12 +00:00

82 lines
2.3 KiB
C

/* sd2iec - SD/MMC to Commodore serial bus interface/controller
Copyright (C) 2007-2016 Ingo Korb <ingo@akana.de>
Inspired by MMC2IEC by Lars Pontoppidan et al.
FAT filesystem access based on code from ChaN and Jim Brain, see ff.c|h.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License only.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
p00cache.c: [PSUR]00 name cache
*/
#include <stddef.h>
#include <string.h>
#include <stdio.h>
#include "config.h"
#include "dirent.h"
#include "p00cache.h"
#include "uart.h"
typedef struct {
uint32_t cluster;
uint8_t name[CBM_NAME_LENGTH];
} p00name_t;
static P00CACHE_ATTRIB p00name_t p00cache[CONFIG_P00CACHE_SIZE / sizeof(p00name_t)];
static uint8_t cache_part;
static unsigned int entries;
void p00cache_invalidate(void) {
cache_part = -1;
entries = 0;
}
uint8_t *p00cache_lookup(uint8_t part, uint32_t cluster) {
/* fail if it's for a different partition */
if (part != cache_part)
return NULL;
/* linear search for the correct cluster number */
/* (binary search was only 6-8% faster overall) */
for (unsigned int i=0; i<entries; i++) {
if (p00cache[i].cluster == cluster)
return p00cache[i].name;
}
/* noting found */
return NULL;
}
void p00cache_add(uint8_t part, uint32_t cluster, uint8_t *name) {
/* don't add if the cache is full */
if (entries == sizeof(p00cache)/sizeof(p00cache[0]))
return;
/* invalidate if it's for a different partition */
// FIXME: ignore instead and add invalidate to CP?
if (part != cache_part) {
p00cache_invalidate();
cache_part = part;
}
/* add entry at end of list */
p00cache[entries].cluster = cluster;
memcpy(p00cache[entries].name, name, CBM_NAME_LENGTH);
entries++;
}