nodemcu-firmware/components/spiffs/spiffs_cache.c

304 lines
8.7 KiB
C

/*
* spiffs_cache.c
*
* Created on: Jun 23, 2013
* Author: petera
*/
#include "spiffs.h"
#include "spiffs_nucleus.h"
#if SPIFFS_CACHE
// returns cached page for give page index, or null if no such cached page
static spiffs_cache_page *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;
}
// frees cached page
static s32_t 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 %i objid %04x\n", ix, cp->obj_id);
} else {
SPIFFS_CACHE_DBG("CACHE_FREE: free cache page %i pix %04x\n", ix, cp->pix);
}
}
return res;
}
// removes the oldest accessed cached page
static s32_t 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;
}
// allocates a new cached page and returns it, or null if all cache pages are busy
static spiffs_cache_page *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;
}
// drops the cache page for give page index
void spiffs_cache_drop_page(spiffs *fs, spiffs_page_ix pix) {
spiffs_cache_page *cp = spiffs_cache_page_get(fs, pix);
if (cp) {
spiffs_cache_page_free(fs, cp->ix, 0);
}
}
// ------------------------------
// 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) {
#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;
}
// writes to spi flash and/or the cache
s32_t spiffs_phys_wr(
spiffs *fs,
u8_t op,
spiffs_file fh,
u32_t addr,
u32_t len,
u8_t *src) {
(void)fh;
spiffs_page_ix pix = SPIFFS_PADDR_TO_PAGE(fs, addr);
spiffs_cache *cache = spiffs_get_cache(fs);
spiffs_cache_page *cp = spiffs_cache_page_get(fs, pix);
if (cp && (op & SPIFFS_OP_COM_MASK) != SPIFFS_OP_C_WRTHRU) {
// have a cache page
// copy in data to cache page
if ((op & SPIFFS_OP_COM_MASK) == SPIFFS_OP_C_DELE &&
(op & SPIFFS_OP_TYPE_MASK) != SPIFFS_OP_T_OBJ_LU) {
// page is being deleted, wipe from cache - unless it is a lookup page
spiffs_cache_page_free(fs, cp->ix, 0);
return fs->cfg.hal_write_f(addr, len, src);
}
u8_t *mem = spiffs_get_cache_page(fs, cache, cp->ix);
memcpy(&mem[SPIFFS_PADDR_TO_PAGE_OFFSET(fs, addr)], src, len);
cache->last_access++;
cp->last_access = cache->last_access;
if (cp->flags & SPIFFS_CACHE_FLAG_WRTHRU) {
// page is being updated, no write-cache, just pass thru
return fs->cfg.hal_write_f(addr, len, src);
} else {
return SPIFFS_OK;
}
} else {
// no cache page, no write cache - just write thru
return fs->cfg.hal_write_f(addr, len, src);
}
}
#if SPIFFS_CACHE_WR
// returns the cache page that this fd refers, or null if no cache page
spiffs_cache_page *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;
}
// allocates a new cache page and refers this to given fd - flushes an old cache
// page if all cache is busy
spiffs_cache_page *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;
}
// unrefers all fds that this cache page refers to and releases the cache page
void spiffs_cache_fd_release(spiffs *fs, spiffs_cache_page *cp) {
if (cp == 0) return;
u32_t i;
spiffs_fd *fds = (spiffs_fd *)fs->fd_space;
for (i = 0; i < fs->fd_count; i++) {
spiffs_fd *cur_fd = &fds[i];
if (cur_fd->file_nbr != 0 && cur_fd->cache_page == cp) {
cur_fd->cache_page = 0;
}
}
spiffs_cache_page_free(fs, cp->ix, 0);
cp->obj_id = 0;
}
#endif
// initializes the cache
void 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;
}
}
#endif // SPIFFS_CACHE