// reads from spi flash or the cache
s32_t spiffs_phys_rd(
spiffs *fs,
u8_t op,
spiffs_file fh,
u32_t addr,
u32_t len,
u8_t *dst) {
(void)fh;
s32_t res = SPIFFS_OK;
spiffs_cache *cache = spiffs_get_cache(fs);
spiffs_cache_page *cp = spiffs_cache_page_get(fs, SPIFFS_PADDR_TO_PAGE(fs, addr));
cache->last_access++;
if (cp) {
// we've already got one, you see
#if SPIFFS_CACHE_STATS
fs->cache_hits++;
#endif
cp->last_access = cache->last_access;
u8_t *mem = spiffs_get_cache_page(fs, cache, cp->ix);
memcpy(dst, &mem[SPIFFS_PADDR_TO_PAGE_OFFSET(fs, addr)], len);
} else {
if ((op & SPIFFS_OP_TYPE_MASK) == SPIFFS_OP_T_OBJ_LU2) {
// for second layer lookup functions, we do not cache in order to prevent shredding
return SPIFFS_HAL_READ(fs, addr, len, dst);
}
#if SPIFFS_CACHE_STATS
fs->cache_misses++;
#endif
// this operation will always free one cache page (unless all already free),
// the result code stems from the write operation of the possibly freed cache page
res = spiffs_cache_page_remove_oldest(fs, SPIFFS_CACHE_FLAG_TYPE_WR, 0);
cp = spiffs_cache_page_allocate(fs);
if (cp) {
cp->flags = SPIFFS_CACHE_FLAG_WRTHRU;
cp->pix = SPIFFS_PADDR_TO_PAGE(fs, addr);
s32_t res2 = SPIFFS_HAL_READ(fs,
addr - SPIFFS_PADDR_TO_PAGE_OFFSET(fs, addr),
SPIFFS_CFG_LOG_PAGE_SZ(fs),
spiffs_get_cache_page(fs, cache, cp->ix));
if (res2 != SPIFFS_OK) {
// honor read failure before possible write failure (bad idea?)
res = res2;
}
u8_t *mem = spiffs_get_cache_page(fs, cache, cp->ix);
memcpy(dst, &mem[SPIFFS_PADDR_TO_PAGE_OFFSET(fs, addr)], len);
} else {
// this will never happen, last resort for sake of symmetry
s32_t res2 = SPIFFS_HAL_READ(fs, addr, len, dst);
if (res2 != SPIFFS_OK) {
// honor read failure before possible write failure (bad idea?)
res = res2;
}
}
}
return res;
}
// allocates a new cache page and refers this to given fd - flushes an old cache
// page if all cache is busy
spiffs_cache_page *ICACHE_FLASH_ATTR spiffs_cache_page_allocate_by_fd(spiffs *fs, spiffs_fd *fd) {
// before this function is called, it is ensured that there is no already existing
// cache page with same object id
spiffs_cache_page_remove_oldest(fs, SPIFFS_CACHE_FLAG_TYPE_WR, 0);
spiffs_cache_page *cp = spiffs_cache_page_allocate(fs);
if (cp == 0) {
// could not get cache page
return 0;
}
cp->flags = SPIFFS_CACHE_FLAG_TYPE_WR;
cp->obj_id = fd->obj_id;
fd->cache_page = cp;
return cp;
}
// reads from spi flash or the cache
s32_t ICACHE_FLASH_ATTR
spiffs_phys_rd(
spiffs *fs,
u8_t op,
spiffs_file fh,
u32_t addr,
u32_t len,
u8_t *dst) {
(void)fh;
s32_t res = SPIFFS_OK;
spiffs_cache *cache = spiffs_get_cache(fs);
spiffs_cache_page *cp = spiffs_cache_page_get(fs, SPIFFS_PADDR_TO_PAGE(fs, addr));
cache->last_access++;
if (cp) {
#if SPIFFS_CACHE_STATS
fs->cache_hits++;
#endif
cp->last_access = cache->last_access;
} else {
if ((op & SPIFFS_OP_TYPE_MASK) == SPIFFS_OP_T_OBJ_LU2) {
// for second layer lookup functions, we do not cache in order to prevent shredding
return fs->cfg.hal_read_f(
addr ,
len,
dst);
}
#if SPIFFS_CACHE_STATS
fs->cache_misses++;
#endif
res = spiffs_cache_page_remove_oldest(fs, SPIFFS_CACHE_FLAG_TYPE_WR, 0);
cp = spiffs_cache_page_allocate(fs);
if (cp) {
cp->flags = SPIFFS_CACHE_FLAG_WRTHRU;
cp->pix = SPIFFS_PADDR_TO_PAGE(fs, addr);
}
s32_t res2 = fs->cfg.hal_read_f(
addr - SPIFFS_PADDR_TO_PAGE_OFFSET(fs, addr),
SPIFFS_CFG_LOG_PAGE_SZ(fs),
spiffs_get_cache_page(fs, cache, cp->ix));
if (res2 != SPIFFS_OK) {
res = res2;
}
}
u8_t *mem = spiffs_get_cache_page(fs, cache, cp->ix);
memcpy(dst, &mem[SPIFFS_PADDR_TO_PAGE_OFFSET(fs, addr)], len);
return res;
}
