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allow to configure file/read/write cache separate size
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@matthieu-c-tagheuer
matthieu-c-tagheuer committed Apr 30, 2024
1 parent 75fed00 commit 0f03b3f
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Showing 2 changed files with 30 additions and 13 deletions.
39 changes: 26 additions & 13 deletions lfs.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -94,7 +94,7 @@ 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);
memset(pcache->buffer, 0xff, lfs->prog_cache_size);
pcache->block = LFS_BLOCK_NULL;
}

Expand Down Expand Up @@ -178,7 +178,7 @@ static int lfs_bd_read_raw(lfs_t *lfs,
if (reverse) {
lfs_size_t msize;
moff = off + size;
msize = lfs_min(hint, lfs->cfg->cache_size);
msize = lfs_min(hint, lfs->read_cache_size);
if (moff > msize)
moff = lfs_alignup(moff - msize, lfs->cfg->read_size);
else
Expand All @@ -190,7 +190,7 @@ static int lfs_bd_read_raw(lfs_t *lfs,
lfs_alignup(moff+hint, lfs->cfg->read_size),
lfs->cfg->block_size)
- rcache->off,
lfs->cfg->cache_size);
lfs->read_cache_size);
int err = lfs->cfg->read(lfs->cfg, rcache->block,
rcache->off, rcache->buffer, rcache->size);
LFS_ASSERT(err <= 0);
Expand Down Expand Up @@ -331,18 +331,18 @@ static int lfs_bd_prog(lfs_t *lfs,
while (size > 0) {
if (block == pcache->block &&
off >= pcache->off &&
off < pcache->off + lfs->cfg->cache_size) {
off < pcache->off + lfs->prog_cache_size) {
// already fits in pcache?
lfs_size_t diff = lfs_min(size,
lfs->cfg->cache_size - (off-pcache->off));
lfs->prog_cache_size - (off-pcache->off));
memcpy(&pcache->buffer[off-pcache->off], data, diff);

data += diff;
off += diff;
size -= diff;

pcache->size = lfs_max(pcache->size, off - pcache->off);
if (pcache->size == lfs->cfg->cache_size) {
if (pcache->size == lfs->prog_cache_size) {
// eagerly flush out pcache if we fill up
int err = lfs_bd_flush(lfs, pcache, rcache, validate);
if (err) {
Expand All @@ -357,7 +357,7 @@ static int lfs_bd_prog(lfs_t *lfs,
// entire block or manually flushing the pcache
LFS_ASSERT(pcache->block == LFS_BLOCK_NULL);

if (size >= lfs->cfg->cache_size) {
if (size >= lfs->prog_cache_size) {
/* data do not fit in cache, direct write */
int err = lfs_bd_flush_direct(lfs, rcache, block, off,
data, size, validate);
Expand Down Expand Up @@ -931,7 +931,7 @@ 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);
rcache->size = lfs_min(lfs_alignup(off+hint, lfs->cfg->read_size),
lfs->cfg->cache_size);
lfs->read_cache_size);
int err = lfs_dir_getslice(lfs, dir, gmask, gtag,
rcache->off, rcache->buffer, rcache->size);
if (err < 0) {
Expand Down Expand Up @@ -1845,7 +1845,7 @@ static int lfs_dir_commitcrc(lfs_t *lfs, struct lfs_commit *commit) {

// manually flush here since we don't prog the padding, this confuses
// the caching layer
if (noff >= end || noff >= lfs->pcache.off + lfs->cfg->cache_size) {
if (noff >= end || noff >= lfs->pcache.off + lfs->prog_cache_size) {
// flush buffers
int err = lfs_bd_sync(lfs, &lfs->pcache, &lfs->rcache, false);
if (err) {
Expand Down Expand Up @@ -4279,17 +4279,30 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
// which littlefs currently does not support
LFS_ASSERT((bool)0x80000000);

if (!lfs->cfg->read_cache_size)
lfs->read_cache_size = lfs->cfg->cache_size;
else
lfs->read_cache_size = lfs->cfg->read_cache_size;
if (!lfs->cfg->prog_cache_size)
lfs->prog_cache_size = lfs->cfg->cache_size;
else
lfs->prog_cache_size = lfs->cfg->prog_cache_size;

// validate that the lfs-cfg sizes were initiated properly before
// performing any arithmetic logics with them
LFS_ASSERT(lfs->cfg->read_size != 0);
LFS_ASSERT(lfs->cfg->prog_size != 0);
LFS_ASSERT(lfs->read_cache_size != 0);
LFS_ASSERT(lfs->prog_cache_size != 0);
LFS_ASSERT(lfs->cfg->cache_size != 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->cfg->read_size == 0);
LFS_ASSERT(lfs->cfg->cache_size % lfs->cfg->prog_size == 0);
LFS_ASSERT(lfs->read_cache_size % lfs->cfg->read_size == 0);
LFS_ASSERT(lfs->prog_cache_size % lfs->cfg->prog_size == 0);
LFS_ASSERT(lfs->cfg->block_size % lfs->cfg->cache_size == 0);
LFS_ASSERT(lfs->cfg->block_size % lfs->read_cache_size == 0);
LFS_ASSERT(lfs->cfg->block_size % lfs->prog_cache_size == 0);

// check that the block size is large enough to fit all ctz pointers
LFS_ASSERT(lfs->cfg->block_size >= 128);
Expand Down Expand Up @@ -4319,7 +4332,7 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
if (lfs->cfg->read_buffer) {
lfs->rcache.buffer = lfs->cfg->read_buffer;
} else {
lfs->rcache.buffer = lfs_malloc(lfs->cfg->cache_size);
lfs->rcache.buffer = lfs_malloc(lfs->read_cache_size);
if (!lfs->rcache.buffer) {
err = LFS_ERR_NOMEM;
goto cleanup;
Expand All @@ -4330,7 +4343,7 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
if (lfs->cfg->prog_buffer) {
lfs->pcache.buffer = lfs->cfg->prog_buffer;
} else {
lfs->pcache.buffer = lfs_malloc(lfs->cfg->cache_size);
lfs->pcache.buffer = lfs_malloc(lfs->prog_cache_size);
if (!lfs->pcache.buffer) {
err = LFS_ERR_NOMEM;
goto cleanup;
Expand Down
4 changes: 4 additions & 0 deletions lfs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -222,6 +222,8 @@ struct lfs_config {
// data and reducing the number of disk accesses. Must be a multiple of the
// read and program sizes, and a factor of the block size.
lfs_size_t cache_size;
lfs_size_t read_cache_size;
lfs_size_t prog_cache_size;

// Size of the lookahead buffer in bytes. A larger lookahead buffer
// increases the number of blocks found during an allocation pass. The
Expand Down Expand Up @@ -435,6 +437,8 @@ typedef struct lfs_gstate {
typedef struct lfs {
lfs_cache_t rcache;
lfs_cache_t pcache;
lfs_size_t read_cache_size;
lfs_size_t prog_cache_size;

lfs_block_t root[2];
struct lfs_mlist {
Expand Down

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