Added more configurable utils

Note: It's still expected to modify lfs_utils.h when porting littlefs
to a new target/system. There's just too much room for system-specific
improvements, such as taking advantage of CRC hardware.

Rather, encouraging modification of lfs_util.h and making it easy to
modify and debug should result in better integration with the consuming
systems.

This just adds a bunch of quality-of-life improvements that should help
development and integration in littlefs.

- Macros that require no side-effects are all-caps
- System includes are only brought in when needed
- Malloc/free wrappers
- LFS_NO_* checks for quickly disabling things at the command line
- At least a little-bit more docs
This commit is contained in:
Christopher Haster
2018-01-29 15:20:12 -06:00
parent a0a55fb9e5
commit a3fd2d4d6d
3 changed files with 103 additions and 43 deletions

52
lfs.c
View File

@@ -18,17 +18,13 @@
#include "lfs.h"
#include "lfs_util.h"
#include <string.h>
#include <stdlib.h>
#include <assert.h>
/// Caching block device operations ///
static int lfs_cache_read(lfs_t *lfs, lfs_cache_t *rcache,
const lfs_cache_t *pcache, lfs_block_t block,
lfs_off_t off, void *buffer, lfs_size_t size) {
uint8_t *data = buffer;
assert(block < lfs->cfg->block_count);
LFS_ASSERT(block < lfs->cfg->block_count);
while (size > 0) {
if (pcache && block == pcache->block && off >= pcache->off &&
@@ -153,7 +149,7 @@ static int lfs_cache_prog(lfs_t *lfs, lfs_cache_t *pcache,
lfs_cache_t *rcache, lfs_block_t block,
lfs_off_t off, const void *buffer, lfs_size_t size) {
const uint8_t *data = buffer;
assert(block < lfs->cfg->block_count);
LFS_ASSERT(block < lfs->cfg->block_count);
while (size > 0) {
if (block == pcache->block && off >= pcache->off &&
@@ -180,7 +176,7 @@ static int lfs_cache_prog(lfs_t *lfs, lfs_cache_t *pcache,
// pcache must have been flushed, either by programming and
// entire block or manually flushing the pcache
assert(pcache->block == 0xffffffff);
LFS_ASSERT(pcache->block == 0xffffffff);
if (off % lfs->cfg->prog_size == 0 &&
size >= lfs->cfg->prog_size) {
@@ -1130,7 +1126,7 @@ static int lfs_ctz_find(lfs_t *lfs,
return err;
}
assert(head >= 2 && head <= lfs->cfg->block_count);
LFS_ASSERT(head >= 2 && head <= lfs->cfg->block_count);
current -= 1 << skip;
}
@@ -1150,7 +1146,7 @@ static int lfs_ctz_extend(lfs_t *lfs,
if (err) {
return err;
}
assert(nblock >= 2 && nblock <= lfs->cfg->block_count);
LFS_ASSERT(nblock >= 2 && nblock <= lfs->cfg->block_count);
if (true) {
err = lfs_bd_erase(lfs, nblock);
@@ -1221,7 +1217,7 @@ static int lfs_ctz_extend(lfs_t *lfs,
}
}
assert(head >= 2 && head <= lfs->cfg->block_count);
LFS_ASSERT(head >= 2 && head <= lfs->cfg->block_count);
}
*block = nblock;
@@ -1347,12 +1343,12 @@ int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
if (lfs->cfg->file_buffer) {
file->cache.buffer = lfs->cfg->file_buffer;
} else if ((file->flags & 3) == LFS_O_RDONLY) {
file->cache.buffer = malloc(lfs->cfg->read_size);
file->cache.buffer = lfs_malloc(lfs->cfg->read_size);
if (!file->cache.buffer) {
return LFS_ERR_NOMEM;
}
} else {
file->cache.buffer = malloc(lfs->cfg->prog_size);
file->cache.buffer = lfs_malloc(lfs->cfg->prog_size);
if (!file->cache.buffer) {
return LFS_ERR_NOMEM;
}
@@ -1378,7 +1374,7 @@ int lfs_file_close(lfs_t *lfs, lfs_file_t *file) {
// clean up memory
if (!lfs->cfg->file_buffer) {
free(file->cache.buffer);
lfs_free(file->cache.buffer);
}
return err;
@@ -1527,7 +1523,7 @@ int lfs_file_sync(lfs_t *lfs, lfs_file_t *file) {
return err;
}
assert(entry.d.type == LFS_TYPE_REG);
LFS_ASSERT(entry.d.type == LFS_TYPE_REG);
entry.d.u.file.head = file->head;
entry.d.u.file.size = file->size;
@@ -1753,7 +1749,7 @@ int lfs_file_truncate(lfs_t *lfs, lfs_file_t *file, lfs_off_t size) {
// flush+seek if not already at end
if (file->pos != oldsize) {
int err = lfs_file_seek(lfs, file, 0, SEEK_END);
int err = lfs_file_seek(lfs, file, 0, LFS_SEEK_END);
if (err < 0) {
return err;
}
@@ -1886,7 +1882,7 @@ int lfs_remove(lfs_t *lfs, const char *path) {
return res;
}
assert(res); // must have pred
LFS_ASSERT(res); // must have pred
cwd.d.tail[0] = dir.d.tail[0];
cwd.d.tail[1] = dir.d.tail[1];
@@ -2003,7 +1999,7 @@ int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath) {
return res;
}
assert(res); // must have pred
LFS_ASSERT(res); // must have pred
newcwd.d.tail[0] = dir.d.tail[0];
newcwd.d.tail[1] = dir.d.tail[1];
@@ -2026,7 +2022,7 @@ 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 = malloc(lfs->cfg->read_size);
lfs->rcache.buffer = lfs_malloc(lfs->cfg->read_size);
if (!lfs->rcache.buffer) {
return LFS_ERR_NOMEM;
}
@@ -2037,30 +2033,30 @@ 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 = malloc(lfs->cfg->prog_size);
lfs->pcache.buffer = lfs_malloc(lfs->cfg->prog_size);
if (!lfs->pcache.buffer) {
return LFS_ERR_NOMEM;
}
}
// setup lookahead, round down to nearest 32-bits
assert(lfs->cfg->lookahead % 32 == 0);
assert(lfs->cfg->lookahead > 0);
LFS_ASSERT(lfs->cfg->lookahead % 32 == 0);
LFS_ASSERT(lfs->cfg->lookahead > 0);
if (lfs->cfg->lookahead_buffer) {
lfs->free.buffer = lfs->cfg->lookahead_buffer;
} else {
lfs->free.buffer = malloc(lfs->cfg->lookahead/8);
lfs->free.buffer = lfs_malloc(lfs->cfg->lookahead/8);
if (!lfs->free.buffer) {
return LFS_ERR_NOMEM;
}
}
// check that program and read sizes are multiples of the block size
assert(lfs->cfg->prog_size % lfs->cfg->read_size == 0);
assert(lfs->cfg->block_size % lfs->cfg->prog_size == 0);
LFS_ASSERT(lfs->cfg->prog_size % lfs->cfg->read_size == 0);
LFS_ASSERT(lfs->cfg->block_size % lfs->cfg->prog_size == 0);
// check that the block size is large enough to fit ctz pointers
assert(4*lfs_npw2(0xffffffff / (lfs->cfg->block_size-2*4))
LFS_ASSERT(4*lfs_npw2(0xffffffff / (lfs->cfg->block_size-2*4))
<= lfs->cfg->block_size);
// setup default state
@@ -2076,15 +2072,15 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
static int lfs_deinit(lfs_t *lfs) {
// free allocated memory
if (!lfs->cfg->read_buffer) {
free(lfs->rcache.buffer);
lfs_free(lfs->rcache.buffer);
}
if (!lfs->cfg->prog_buffer) {
free(lfs->pcache.buffer);
lfs_free(lfs->pcache.buffer);
}
if (!lfs->cfg->lookahead_buffer) {
free(lfs->free.buffer);
lfs_free(lfs->free.buffer);
}
return 0;