openharmony/third_party_littlefs
1
0
Fork 0
mirror of https://gitee.com/openharmony/third_party_littlefs synced 2024-11-23 06:50:37 +00:00
Code Issues Actions 1 Packages Projects Releases Wiki Activity

Changed lfs_crc to match more common API

Browse Source 
In looking at the common CRC APIs out there, this seemed the most
common. At least more common than the current modified-in-place pointer
API. It also seems to have a slightly better code footprint. I'm blaming
pointer optimization issues.

One downside is that lfs_crc can't report errors, however it was already
assumed that lfs_crc can not error.
This commit is contained in:
Christopher Haster 2018-08-07 14:59:44 -05:00
parent 3b3981eb74
commit 10f45ac02f
3 changed files with 17 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
lfs.c
View File

@ -121,7 +121,7 @@ static int lfs_cache_crc(lfs_t *lfs,
return err;
}
lfs_crc(crc, &c, 1);
*crc = lfs_crc(*crc, &c, 1);
}
return 0;
@ -236,7 +236,7 @@ static int lfs_bd_cmp(lfs_t *lfs, lfs_block_t block,
return lfs_cache_cmp(lfs, NULL, &lfs->rcache, block, off, buffer, size);
}
static int lfs_bd_crc(lfs_t *lfs, lfs_block_t block,
static int lfs_bd_crc32(lfs_t *lfs, lfs_block_t block,
lfs_off_t off, lfs_size_t size, uint32_t *crc) {
return lfs_cache_crc(lfs, NULL, &lfs->rcache, block, off, size, crc);
}
@ -562,7 +562,7 @@ static int lfs_commit_attr(lfs_t *lfs, struct lfs_commit *commit,
// write out tag
uint32_t ntag = lfs_tole32((tag & 0x7fffffff) ^ commit->ptag);
lfs_crc(&commit->crc, &ntag, sizeof(ntag));
commit->crc = lfs_crc(commit->crc, &ntag, sizeof(ntag));
int err = lfs_bd_prog(lfs, commit->block, commit->off,
&ntag, sizeof(ntag));
if (err) {
@ -572,7 +572,7 @@ static int lfs_commit_attr(lfs_t *lfs, struct lfs_commit *commit,
if (!(tag & 0x80000000)) {
// from memory
lfs_crc(&commit->crc, buffer, size);
commit->crc = lfs_crc(commit->crc, buffer, size);
err = lfs_bd_prog(lfs, commit->block, commit->off, buffer, size);
if (err) {
return err;
@ -588,7 +588,7 @@ static int lfs_commit_attr(lfs_t *lfs, struct lfs_commit *commit,
return err;
}
lfs_crc(&commit->crc, &dat, 1);
commit->crc = lfs_crc(commit->crc, &dat, 1);
err = lfs_bd_prog(lfs, commit->block, commit->off+i, &dat, 1);
if (err) {
return err;
@ -714,7 +714,7 @@ static int lfs_commit_crc(lfs_t *lfs, struct lfs_commit *commit) {
// write out crc
uint32_t footer[2];
footer[0] = lfs_tole32(tag ^ commit->ptag);
lfs_crc(&commit->crc, &footer[0], sizeof(footer[0]));
commit->crc = lfs_crc(commit->crc, &footer[0], sizeof(footer[0]));
footer[1] = lfs_tole32(commit->crc);
err = lfs_bd_prog(lfs, commit->block, commit->off, footer, sizeof(footer));
if (err) {
@ -731,7 +731,7 @@ static int lfs_commit_crc(lfs_t *lfs, struct lfs_commit *commit) {
// successful commit, check checksum to make sure
uint32_t crc = 0xffffffff;
err = lfs_bd_crc(lfs, commit->block, commit->begin,
err = lfs_bd_crc32(lfs, commit->block, commit->begin,
commit->off-lfs_tag_size(tag)-commit->begin, &crc);
if (err) {
return err;
@ -810,7 +810,7 @@ static int32_t lfs_dir_fetchmatch(lfs_t *lfs,
uint32_t crc = 0xffffffff;
dir->rev = lfs_tole32(rev[0]);
lfs_crc(&crc, &dir->rev, sizeof(dir->rev));
crc = lfs_crc(crc, &dir->rev, sizeof(dir->rev));
dir->rev = lfs_fromle32(dir->rev);
dir->off = 0;
@ -835,7 +835,7 @@ static int32_t lfs_dir_fetchmatch(lfs_t *lfs,
return err;
}
lfs_crc(&crc, &tag, sizeof(tag));
crc = lfs_crc(crc, &tag, sizeof(tag));
tag = lfs_fromle32(tag) ^ ptag;
// next commit not yet programmed
@ -879,7 +879,7 @@ static int32_t lfs_dir_fetchmatch(lfs_t *lfs,
dir->locals = templocals;
crc = 0xffffffff;
} else {
err = lfs_bd_crc(lfs, dir->pair[0],
err = lfs_bd_crc32(lfs, dir->pair[0],
off+sizeof(tag), lfs_tag_size(tag), &crc);
if (err) {
if (err == LFS_ERR_CORRUPT) {
@ -1062,7 +1062,7 @@ static int lfs_dir_compact(lfs_t *lfs,
// write out header
uint32_t crc = 0xffffffff;
uint32_t rev = lfs_tole32(dir->rev);
lfs_crc(&crc, &rev, sizeof(rev));
crc = lfs_crc(crc, &rev, sizeof(rev));
err = lfs_bd_prog(lfs, dir->pair[1], 0, &rev, sizeof(rev));
if (err) {
if (err == LFS_ERR_CORRUPT) {

8
lfs_util.c
View File

@ -11,7 +11,7 @@
// Software CRC implementation with small lookup table
void lfs_crc(uint32_t *restrict crc, const void *buffer, size_t size) {
uint32_t lfs_crc(uint32_t crc, const void *buffer, size_t size) {
static const uint32_t rtable[16] = {
0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
@ -22,9 +22,11 @@ void lfs_crc(uint32_t *restrict crc, const void *buffer, size_t size) {
const uint8_t *data = buffer;
for (size_t i = 0; i < size; i++) {
*crc = (*crc >> 4) ^ rtable[(*crc ^ (data[i] >> 0)) & 0xf];
*crc = (*crc >> 4) ^ rtable[(*crc ^ (data[i] >> 4)) & 0xf];
crc = (crc >> 4) ^ rtable[(crc ^ (data[i] >> 0)) & 0xf];
crc = (crc >> 4) ^ rtable[(crc ^ (data[i] >> 4)) & 0xf];
}
return crc;
}

2
lfs_util.h
View File

@ -187,7 +187,7 @@ static inline uint32_t lfs_alignup(uint32_t a, uint32_t alignment) {
}
// Calculate CRC-32 with polynomial = 0x04c11db7
void lfs_crc(uint32_t *crc, const void *buffer, size_t size);
uint32_t lfs_crc(uint32_t crc, const void *buffer, size_t size);
// Allocate memory, only used if buffers are not provided to littlefs
static inline void *lfs_malloc(size_t size) {