Renamed cache_size -> buffer_size

This makes littlefs's usage of the term "cache" an entirely internal
concept and hopefully avoids some confusion about the usefulness of
throwing RAM > block_size at these buffers.

The term cache isn't entirely inaccurate, these buffers do act as
single-line caches, however more often the term cache is used to
describe multi-line caches. Maybe this will be added in littlefs's
future, but the code-size cost makes this change not worth the overhead
at the moment.
This commit is contained in:
Christopher Haster
2020-11-26 15:27:01 -06:00
parent aa46bb68ca
commit 499083765c
7 changed files with 33 additions and 33 deletions

38
lfs.c
View File

@@ -23,7 +23,7 @@
#define LFS_CFG_BLOCK_SIZE(lfs) ((void)lfs, LFS_BLOCK_SIZE)
#define LFS_CFG_BLOCK_COUNT(lfs) ((void)lfs, LFS_BLOCK_COUNT)
#define LFS_CFG_BLOCK_CYCLES(lfs) ((void)lfs, LFS_BLOCK_CYCLES)
#define LFS_CFG_CACHE_SIZE(lfs) ((void)lfs, LFS_CACHE_SIZE)
#define LFS_CFG_BUFFER_SIZE(lfs) ((void)lfs, LFS_BUFFER_SIZE)
#define LFS_CFG_LOOKAHEAD_SIZE(lfs) ((void)lfs, LFS_LOOKAHEAD_SIZE)
#define LFS_CFG_READ_BUFFER(lfs) ((void)lfs, LFS_READ_BUFFER)
#define LFS_CFG_PROG_BUFFER(lfs) ((void)lfs, LFS_PROG_BUFFER)
@@ -46,7 +46,7 @@
#define LFS_CFG_BLOCK_SIZE(lfs) lfs->cfg->block_size
#define LFS_CFG_BLOCK_COUNT(lfs) lfs->cfg->block_count
#define LFS_CFG_BLOCK_CYCLES(lfs) lfs->cfg->block_cycles
#define LFS_CFG_CACHE_SIZE(lfs) lfs->cfg->cache_size
#define LFS_CFG_BUFFER_SIZE(lfs) lfs->cfg->buffer_size
#define LFS_CFG_LOOKAHEAD_SIZE(lfs) lfs->cfg->lookahead_size
#define LFS_CFG_READ_BUFFER(lfs) lfs->cfg->read_buffer
#define LFS_CFG_PROG_BUFFER(lfs) lfs->cfg->prog_buffer
@@ -83,7 +83,7 @@ static inline void lfs_cache_drop(lfs_t *lfs, lfs_cache_t *rcache) {
static inline void lfs_cache_zero(lfs_t *lfs, lfs_cache_t *pcache) {
// zero to avoid information leak
memset(pcache->buffer, 0xff, LFS_CFG_CACHE_SIZE(lfs));
memset(pcache->buffer, 0xff, LFS_CFG_BUFFER_SIZE(lfs));
pcache->block = LFS_BLOCK_NULL;
}
@@ -158,7 +158,7 @@ static int lfs_cache_read(lfs_t *lfs,
lfs_alignup(off+hint, LFS_CFG_READ_SIZE(lfs)),
LFS_CFG_BLOCK_SIZE(lfs))
- rcache->off,
LFS_CFG_CACHE_SIZE(lfs));
LFS_CFG_BUFFER_SIZE(lfs));
int err = LFS_CFG_BD_READ(lfs, rcache->block,
rcache->off, rcache->buffer, rcache->size);
LFS_ASSERT(err <= 0);
@@ -257,10 +257,10 @@ static int lfs_cache_prog(lfs_t *lfs,
while (size > 0) {
if (block == pcache->block &&
off >= pcache->off &&
off < pcache->off + LFS_CFG_CACHE_SIZE(lfs)) {
off < pcache->off + LFS_CFG_BUFFER_SIZE(lfs)) {
// already fits in pcache?
lfs_size_t diff = lfs_min(size,
LFS_CFG_CACHE_SIZE(lfs) - (off-pcache->off));
LFS_CFG_BUFFER_SIZE(lfs) - (off-pcache->off));
memcpy(&pcache->buffer[off-pcache->off], data, diff);
data += diff;
@@ -268,7 +268,7 @@ static int lfs_cache_prog(lfs_t *lfs,
size -= diff;
pcache->size = lfs_max(pcache->size, off - pcache->off);
if (pcache->size == LFS_CFG_CACHE_SIZE(lfs)) {
if (pcache->size == LFS_CFG_BUFFER_SIZE(lfs)) {
// eagerly flush out pcache if we fill up
int err = lfs_cache_flush(lfs, pcache, rcache, validate);
if (err) {
@@ -694,7 +694,7 @@ static int lfs_dir_getread(lfs_t *lfs, const lfs_mdir_t *dir,
rcache->block = LFS_BLOCK_INLINE;
rcache->off = lfs_aligndown(off, LFS_CFG_READ_SIZE(lfs));
rcache->size = lfs_min(lfs_alignup(off+hint, LFS_CFG_READ_SIZE(lfs)),
LFS_CFG_CACHE_SIZE(lfs));
LFS_CFG_BUFFER_SIZE(lfs));
int err = lfs_dir_getslice(lfs, dir, gmask, gtag,
rcache->off, rcache->buffer, rcache->size);
if (err < 0) {
@@ -1787,7 +1787,7 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
for (lfs_file_t *f = (lfs_file_t*)lfs->mlist; f; f = f->next) {
if (dir != &f->m && lfs_pair_cmp(f->m.pair, dir->pair) == 0 &&
f->type == LFS_TYPE_REG && (f->flags & LFS_F_INLINE) &&
f->ctz.size > LFS_CFG_CACHE_SIZE(lfs)) {
f->ctz.size > LFS_CFG_BUFFER_SIZE(lfs)) {
int err = lfs_file_outline(lfs, f);
if (err) {
return err;
@@ -2549,7 +2549,7 @@ static int lfs_file_opencommon(lfs_t *lfs, lfs_file_t *file,
if (LFS_FILE_CFG_BUFFER(file)) {
file->cache.buffer = LFS_FILE_CFG_BUFFER(file);
} else {
file->cache.buffer = lfs_malloc(LFS_CFG_CACHE_SIZE(lfs));
file->cache.buffer = lfs_malloc(LFS_CFG_BUFFER_SIZE(lfs));
if (!file->cache.buffer) {
err = LFS_ERR_NOMEM;
goto cleanup;
@@ -2566,7 +2566,7 @@ static int lfs_file_opencommon(lfs_t *lfs, lfs_file_t *file,
file->flags |= LFS_F_INLINE;
file->cache.block = file->ctz.head;
file->cache.off = 0;
file->cache.size = LFS_CFG_CACHE_SIZE(lfs);
file->cache.size = LFS_CFG_BUFFER_SIZE(lfs);
// don't always read (may be new/trunc file)
if (file->ctz.size > 0) {
@@ -2696,7 +2696,7 @@ static int lfs_file_relocate(lfs_t *lfs, lfs_file_t *file) {
}
// copy over new state of file
memcpy(file->cache.buffer, lfs->pcache.buffer, LFS_CFG_CACHE_SIZE(lfs));
memcpy(file->cache.buffer, lfs->pcache.buffer, LFS_CFG_BUFFER_SIZE(lfs));
file->cache.block = lfs->pcache.block;
file->cache.off = lfs->pcache.off;
file->cache.size = lfs->pcache.size;
@@ -2989,7 +2989,7 @@ lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
if ((file->flags & LFS_F_INLINE) &&
lfs_max(file->pos+nsize, file->ctz.size) >
lfs_min(0x3fe, lfs_min(
LFS_CFG_CACHE_SIZE(lfs), LFS_CFG_BLOCK_SIZE(lfs)/8))) {
LFS_CFG_BUFFER_SIZE(lfs), LFS_CFG_BLOCK_SIZE(lfs)/8))) {
// inline file doesn't fit anymore
int err = lfs_file_outline(lfs, file);
if (err) {
@@ -3542,13 +3542,13 @@ static int lfs_initcommon(lfs_t *lfs) {
// performing any arithmetic logics with them
LFS_ASSERT(LFS_CFG_READ_SIZE(lfs) != 0);
LFS_ASSERT(LFS_CFG_PROG_SIZE(lfs) != 0);
LFS_ASSERT(LFS_CFG_CACHE_SIZE(lfs) != 0);
LFS_ASSERT(LFS_CFG_BUFFER_SIZE(lfs) != 0);
// check that block size is a multiple of cache size is a multiple
// of prog and read sizes
LFS_ASSERT(LFS_CFG_CACHE_SIZE(lfs) % LFS_CFG_READ_SIZE(lfs) == 0);
LFS_ASSERT(LFS_CFG_CACHE_SIZE(lfs) % LFS_CFG_PROG_SIZE(lfs) == 0);
LFS_ASSERT(LFS_CFG_BLOCK_SIZE(lfs) % LFS_CFG_CACHE_SIZE(lfs) == 0);
LFS_ASSERT(LFS_CFG_BUFFER_SIZE(lfs) % LFS_CFG_READ_SIZE(lfs) == 0);
LFS_ASSERT(LFS_CFG_BUFFER_SIZE(lfs) % LFS_CFG_PROG_SIZE(lfs) == 0);
LFS_ASSERT(LFS_CFG_BLOCK_SIZE(lfs) % LFS_CFG_BUFFER_SIZE(lfs) == 0);
// check that the block size is large enough to fit ctz pointers
LFS_ASSERT(4*lfs_npw2(0xffffffff / (LFS_CFG_BLOCK_SIZE(lfs)-2*4))
@@ -3567,7 +3567,7 @@ static int lfs_initcommon(lfs_t *lfs) {
if (LFS_CFG_READ_BUFFER(lfs)) {
lfs->rcache.buffer = LFS_CFG_READ_BUFFER(lfs);
} else {
lfs->rcache.buffer = lfs_malloc(LFS_CFG_CACHE_SIZE(lfs));
lfs->rcache.buffer = lfs_malloc(LFS_CFG_BUFFER_SIZE(lfs));
if (!lfs->rcache.buffer) {
err = LFS_ERR_NOMEM;
goto cleanup;
@@ -3578,7 +3578,7 @@ static int lfs_initcommon(lfs_t *lfs) {
if (LFS_CFG_PROG_BUFFER(lfs)) {
lfs->pcache.buffer = LFS_CFG_PROG_BUFFER(lfs);
} else {
lfs->pcache.buffer = lfs_malloc(LFS_CFG_CACHE_SIZE(lfs));
lfs->pcache.buffer = lfs_malloc(LFS_CFG_BUFFER_SIZE(lfs));
if (!lfs->pcache.buffer) {
err = LFS_ERR_NOMEM;
goto cleanup;