// removes the oldest accessed cached page
static s32_t ICACHE_FLASH_ATTR
spiffs_cache_page_remove_oldest(spiffs *fs, u8_t flag_mask, u8_t flags) {
s32_t res = SPIFFS_OK;
spiffs_cache *cache = spiffs_get_cache(fs);
if ((cache->cpage_use_map & cache->cpage_use_mask) != cache->cpage_use_mask) {
// at least one free cpage
return SPIFFS_OK;
}
// all busy, scan thru all to find the cpage which has oldest access
int i;
int cand_ix = -1;
u32_t oldest_val = 0;
for (i = 0; i < cache->cpage_count; i++) {
spiffs_cache_page *cp = spiffs_get_cache_page_hdr(fs, cache, i);
if ((cache->last_access - cp->last_access) > oldest_val &&
(cp->flags & flag_mask) == flags) {
oldest_val = cache->last_access - cp->last_access;
cand_ix = i;
}
}
if (cand_ix >= 0) {
res = spiffs_cache_page_free(fs, cand_ix, 1);
}
return res;
}
// frees cached page
static s32_t ICACHE_FLASH_ATTR
spiffs_cache_page_free(spiffs *fs, int ix, u8_t write_back) {
s32_t res = SPIFFS_OK;
spiffs_cache *cache = spiffs_get_cache(fs);
spiffs_cache_page *cp = spiffs_get_cache_page_hdr(fs, cache, ix);
if (cache->cpage_use_map & (1<<ix)) {
if (write_back &&
(cp->flags & SPIFFS_CACHE_FLAG_TYPE_WR) == 0 &&
(cp->flags & SPIFFS_CACHE_FLAG_DIRTY)) {
u8_t *mem = spiffs_get_cache_page(fs, cache, ix);
res = fs->cfg.hal_write_f(SPIFFS_PAGE_TO_PADDR(fs, cp->pix), SPIFFS_CFG_LOG_PAGE_SZ(fs), mem);
}
cp->flags = 0;
cache->cpage_use_map &= ~(1 << ix);
if (cp->flags & SPIFFS_CACHE_FLAG_TYPE_WR) {
SPIFFS_CACHE_DBG("CACHE_FREE: free cache page %d objid %04x\n", ix, cp->obj_id);
} else {
SPIFFS_CACHE_DBG("CACHE_FREE: free cache page %d pix %04x\n", ix, cp->pix);
}
}
return res;
}
// initializes the cache
void ICACHE_FLASH_ATTR
spiffs_cache_init(spiffs *fs) {
if (fs->cache == 0) return;
u32_t sz = fs->cache_size;
u32_t cache_mask = 0;
int i;
int cache_entries =
(sz - sizeof(spiffs_cache)) / (SPIFFS_CACHE_PAGE_SIZE(fs));
if (cache_entries <= 0) return;
for (i = 0; i < cache_entries; i++) {
cache_mask <<= 1;
cache_mask |= 1;
}
spiffs_cache cache;
memset(&cache, 0, sizeof(spiffs_cache));
cache.cpage_count = cache_entries;
cache.cpages = (u8_t *)((u8_t *)fs->cache + sizeof(spiffs_cache));
cache.cpage_use_map = 0xffffffff;
cache.cpage_use_mask = cache_mask;
memcpy(fs->cache, &cache, sizeof(spiffs_cache));
spiffs_cache *c = spiffs_get_cache(fs);
memset(c->cpages, 0, c->cpage_count * SPIFFS_CACHE_PAGE_SIZE(fs));
c->cpage_use_map &= ~(c->cpage_use_mask);
for (i = 0; i < cache.cpage_count; i++) {
spiffs_get_cache_page_hdr(fs, c, i)->ix = i;
}
}
// returns cached page for give page index, or null if no such cached page
static spiffs_cache_page *ICACHE_FLASH_ATTR spiffs_cache_page_get(spiffs *fs, spiffs_page_ix pix) {
spiffs_cache *cache = spiffs_get_cache(fs);
if ((cache->cpage_use_map & cache->cpage_use_mask) == 0) return 0;
int i;
for (i = 0; i < cache->cpage_count; i++) {
spiffs_cache_page *cp = spiffs_get_cache_page_hdr(fs, cache, i);
if ((cache->cpage_use_map & (1<<i)) &&
(cp->flags & SPIFFS_CACHE_FLAG_TYPE_WR) == 0 &&
cp->pix == pix ) {
SPIFFS_CACHE_DBG("CACHE_GET: have cache page %i for %04x\n", i, pix);
cp->last_access = cache->last_access;
return cp;
}
}
//SPIFFS_CACHE_DBG("CACHE_GET: no cache for %04x\n", pix);
return 0;
}
// allocates a new cached page and returns it, or null if all cache pages are busy
static spiffs_cache_page *ICACHE_FLASH_ATTR spiffs_cache_page_allocate(spiffs *fs) {
spiffs_cache *cache = spiffs_get_cache(fs);
if (cache->cpage_use_map == 0xffffffff) {
// out of cache memory
return 0;
}
int i;
for (i = 0; i < cache->cpage_count; i++) {
if ((cache->cpage_use_map & (1<<i)) == 0) {
spiffs_cache_page *cp = spiffs_get_cache_page_hdr(fs, cache, i);
cache->cpage_use_map |= (1<<i);
cp->last_access = cache->last_access;
SPIFFS_CACHE_DBG("CACHE_ALLO: allocated cache page %i\n", i);
return cp;
}
}
// out of cache entries
return 0;
}
// returns the cache page that this fd refers, or null if no cache page
spiffs_cache_page *ICACHE_FLASH_ATTR spiffs_cache_page_get_by_fd(spiffs *fs, spiffs_fd *fd) {
spiffs_cache *cache = spiffs_get_cache(fs);
if ((cache->cpage_use_map & cache->cpage_use_mask) == 0) {
// all cpages free, no cpage cannot be assigned to obj_id
return 0;
}
int i;
for (i = 0; i < cache->cpage_count; i++) {
spiffs_cache_page *cp = spiffs_get_cache_page_hdr(fs, cache, i);
if ((cache->cpage_use_map & (1<<i)) &&
(cp->flags & SPIFFS_CACHE_FLAG_TYPE_WR) &&
cp->obj_id == fd->obj_id) {
return cp;
}
}
return 0;
}
