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Fixed non-standard behaviour of rdwr streams

Browse Source 
Originally had two seperate positions for reading/writing,
but this is inconsistent with the the posix standard, which
has a single position for reading and writing.

Also added proper handling of when the file is dirty, just
added an internal flag for this state.

Also moved the entry out of the file struct, and rearranged
some members to clean things up.
This commit is contained in:
Christopher Haster 2017-04-23 23:39:50 -05:00
parent 287b54876e
commit 0406442253
4 changed files with 146 additions and 130 deletions
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252
lfs.c
View File

@ -475,8 +475,6 @@ static int lfs_dir_append(lfs_t *lfs, lfs_dir_t *dir,
// check if we fit, if top bit is set we do not and move on
while (true) {
if (dir->d.size + entry->d.len <= lfs->cfg->block_size - 4) {
entry->pair[0] = dir->pair[0];
entry->pair[1] = dir->pair[1];
entry->off = dir->d.size;
dir->d.size += entry->d.len;
return lfs_dir_commit(lfs, dir, entry, data);
@ -491,8 +489,6 @@ static int lfs_dir_append(lfs_t *lfs, lfs_dir_t *dir,
newdir.d.tail[0] = dir->d.tail[0];
newdir.d.tail[1] = dir->d.tail[1];
entry->pair[0] = newdir.pair[0];
entry->pair[1] = newdir.pair[1];
entry->off = newdir.d.size;
newdir.d.size += entry->d.len;
err = lfs_dir_commit(lfs, &newdir, entry, data);
@ -529,7 +525,6 @@ static int lfs_dir_remove(lfs_t *lfs, lfs_dir_t *dir, lfs_entry_t *entry) {
}
}
// TODO easier check for head block? (common case)
if (!(pdir.d.size & 0x80000000)) {
return lfs_dir_shift(lfs, dir, entry);
} else {
@ -546,8 +541,6 @@ static int lfs_dir_next(lfs_t *lfs, lfs_dir_t *dir, lfs_entry_t *entry) {
while (true) {
if (dir->off + sizeof(entry->d) > (0x7fffffff & dir->d.size)) {
if (!(0x80000000 & dir->d.size)) {
entry->pair[0] = dir->pair[0];
entry->pair[1] = dir->pair[1];
entry->off = dir->off;
return LFS_ERR_NOENT;
}
@ -572,8 +565,6 @@ static int lfs_dir_next(lfs_t *lfs, lfs_dir_t *dir, lfs_entry_t *entry) {
dir->pos += entry->d.len;
if ((0xff & entry->d.type) == LFS_TYPE_REG ||
(0xff & entry->d.type) == LFS_TYPE_DIR) {
entry->pair[0] = dir->pair[0];
entry->pair[1] = dir->pair[1];
entry->off = dir->off - entry->d.len;
return 0;
}
@ -972,17 +963,15 @@ static int lfs_index_traverse(lfs_t *lfs,
/// Top level file operations ///
int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
const char *path, int flags) {
file->flags = flags;
// Allocate entry for file if it doesn't exist
// TODO check open files
lfs_dir_t cwd;
int err = lfs_dir_fetch(lfs, &cwd, lfs->root);
if (err) {
return err;
}
err = lfs_dir_find(lfs, &cwd, &file->entry, &path);
lfs_entry_t entry;
err = lfs_dir_find(lfs, &cwd, &entry, &path);
if (err && err != LFS_ERR_NOENT) {
return err;
}
@ -993,32 +982,34 @@ int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
}
// create entry to remember name
file->entry.d.type = LFS_TYPE_REG;
file->entry.d.len = sizeof(file->entry.d) + strlen(path);
file->entry.d.u.file.head = 0;
file->entry.d.u.file.size = 0;
err = lfs_dir_append(lfs, &cwd, &file->entry, path);
entry.d.type = LFS_TYPE_REG;
entry.d.len = sizeof(entry.d) + strlen(path);
entry.d.u.file.head = 0;
entry.d.u.file.size = 0;
err = lfs_dir_append(lfs, &cwd, &entry, path);
if (err) {
return err;
}
} else if (file->entry.d.type == LFS_TYPE_DIR) {
} else if (entry.d.type == LFS_TYPE_DIR) {
return LFS_ERR_ISDIR;
} else if (flags & LFS_O_EXCL) {
return LFS_ERR_EXISTS;
}
file->wpos = 0;
// setup file struct
file->pair[0] = cwd.pair[0];
file->pair[1] = cwd.pair[1];
file->off = entry.off;
file->head = entry.d.u.file.head;
file->size = entry.d.u.file.size;
file->flags = flags;
file->pos = 0;
file->wblock = 0;
file->rpos = 0;
file->rblock = 0;
if (flags & LFS_O_TRUNC) {
file->entry.d.u.file.head = 0;
file->entry.d.u.file.size = 0;
}
if (flags & LFS_O_APPEND) {
file->wpos = file->entry.d.u.file.size;
file->head = 0;
file->size = 0;
}
return 0;
@ -1029,78 +1020,113 @@ int lfs_file_close(lfs_t *lfs, lfs_file_t *file) {
}
static int lfs_file_flush(lfs_t *lfs, lfs_file_t *file) {
if (file->wblock == 0) {
// already in sync, may be rdonly
return 0;
if (file->rblock) {
// just drop read block
file->rblock = 0;
}
// copy over anything after the file
lfs_off_t oldrpos = file->rpos;
lfs_off_t oldwpos = file->wpos;
file->rpos = file->wpos;
file->rblock = 0;
if (file->wblock) {
lfs_off_t pos = file->pos;
while (file->wpos < file->entry.d.u.file.size) {
uint8_t data;
lfs_ssize_t res = lfs_file_read(lfs, file, &data, 1);
if (res < 0) {
return res;
// copy over anything after current branch
lfs_file_t orig = {
.head = file->head,
.size = file->size,
.flags = LFS_O_RDONLY,
.pos = file->pos,
.rblock = 0,
};
while (file->pos < file->size) {
uint8_t data;
lfs_ssize_t res = lfs_file_read(lfs, &orig, &data, 1);
if (res < 0) {
return res;
}
res = lfs_file_write(lfs, file, &data, 1);
if (res < 0) {
return res;
}
}
res = lfs_file_write(lfs, file, &data, 1);
if (res < 0) {
return res;
}
// actual file updates
file->head = file->wblock;
file->size = file->pos;
file->wblock = 0;
file->flags |= LFS_O_DIRTY;
file->pos = pos;
}
// actual file updates
file->entry.d.u.file.head = file->wblock;
file->entry.d.u.file.size = file->wpos;
file->rpos = oldrpos;
file->rblock = 0;
file->wpos = oldwpos;
file->wblock = 0;
return 0;
}
int lfs_file_sync(lfs_t *lfs, lfs_file_t *file) {
if (file->wblock == 0) {
// already in sync, may be rdonly
return 0;
}
int err = lfs_file_flush(lfs, file);
if (err) {
return err;
}
// update dir entry
lfs_dir_t cwd;
err = lfs_dir_fetch(lfs, &cwd, file->entry.pair);
if (err) {
return err;
if (file->flags & LFS_O_DIRTY) {
// update dir entry
lfs_dir_t cwd;
int err = lfs_dir_fetch(lfs, &cwd, file->pair);
if (err) {
return err;
}
lfs_entry_t entry = {.off = file->off};
err = lfs_bd_read(lfs, cwd.pair[0], entry.off,
sizeof(entry.d), &entry.d);
if (err) {
return err;
}
if (entry.d.type != LFS_TYPE_REG) {
// sanity check valid entry
return LFS_ERR_INVAL;
}
entry.d.u.file.head = file->head;
entry.d.u.file.size = file->size;
err = lfs_dir_commit(lfs, &cwd, &entry, NULL);
if (err) {
return err;
}
file->flags &= ~LFS_O_DIRTY;
}
return lfs_dir_commit(lfs, &cwd, &file->entry, NULL);
return 0;
}
lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
void *buffer, lfs_size_t size) {
uint8_t *data = buffer;
size = lfs_min(size, file->entry.d.u.file.size - file->rpos);
lfs_size_t nsize = size;
if ((file->flags & 3) == LFS_O_WRONLY) {
return LFS_ERR_INVAL;
}
if (file->wblock) {
// flush out any writes
int err = lfs_file_flush(lfs, file);
if (err) {
return err;
}
}
size = lfs_min(size, file->size - file->pos);
nsize = size;
while (nsize > 0) {
// check if we need a new block
if (!file->rblock || file->roff == lfs->cfg->block_size) {
int err = lfs_index_find(lfs,
file->entry.d.u.file.head, file->entry.d.u.file.size,
file->rpos, &file->rblock, &file->roff);
int err = lfs_index_find(lfs, file->head, file->size,
file->pos, &file->rblock, &file->roff);
if (err) {
return err;
}
@ -1113,7 +1139,7 @@ lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
return err;
}
file->rpos += diff;
file->pos += diff;
file->roff += diff;
data += diff;
nsize -= diff;
@ -1131,21 +1157,32 @@ lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
return LFS_ERR_INVAL;
}
if (file->rblock) {
// drop any reads
int err = lfs_file_flush(lfs, file);
if (err) {
return err;
}
}
if ((file->flags & LFS_O_APPEND) && file->pos < file->size) {
file->pos = file->size;
}
while (nsize > 0) {
// check if we need a new block
if (!file->wblock || file->woff == lfs->cfg->block_size) {
if (!file->wblock) {
// find out which block we're extending from
int err = lfs_index_find(lfs,
file->entry.d.u.file.head, file->entry.d.u.file.size,
file->wpos, &file->wblock, &file->woff);
int err = lfs_index_find(lfs, file->head, file->size,
file->pos, &file->wblock, &file->woff);
if (err) {
return err;
}
}
// extend file with new blocks
int err = lfs_index_extend(lfs, file->wblock, file->wpos,
int err = lfs_index_extend(lfs, file->wblock, file->pos,
&file->wblock, &file->woff);
if (err) {
return err;
@ -1159,15 +1196,10 @@ lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
return err;
}
file->wpos += diff;
file->pos += diff;
file->woff += diff;
data += diff;
nsize -= diff;
if (file->flags & LFS_O_APPEND) {
file->entry.d.u.file.head = file->wblock;
file->entry.d.u.file.size = file->wpos;
}
}
if (file->flags & LFS_O_SYNC) {
@ -1188,34 +1220,22 @@ lfs_soff_t lfs_file_seek(lfs_t *lfs, lfs_file_t *file,
return err;
}
// rpos is always correct pos, even in append mode
// TODO keep rpos and wpos together?
lfs_off_t prev = file->rpos;
file->rblock = 0;
switch (whence) {
case LFS_SEEK_SET:
file->rpos = off;
break;
// update pos
lfs_off_t pos = file->pos;
case LFS_SEEK_CUR:
file->rpos = file->rpos + off;
break;
case LFS_SEEK_END:
file->rpos = file->entry.d.u.file.size + off;
break;
if (whence == LFS_SEEK_SET) {
file->pos = off;
} else if (whence == LFS_SEEK_CUR) {
file->pos = file->pos + off;
} else if (whence == LFS_SEEK_END) {
file->pos = file->size + off;
}
if (!(file->flags & LFS_O_APPEND)) {
file->wpos = file->rpos;
file->wblock = 0;
}
return prev;
return pos;
}
lfs_soff_t lfs_file_tell(lfs_t *lfs, lfs_file_t *file) {
return file->rpos;
return file->pos;
}
int lfs_file_rewind(lfs_t *lfs, lfs_file_t *file) {
@ -1228,7 +1248,7 @@ int lfs_file_rewind(lfs_t *lfs, lfs_file_t *file) {
}
lfs_soff_t lfs_file_size(lfs_t *lfs, lfs_file_t *file) {
return lfs_max(file->wpos, file->entry.d.u.file.size);
return lfs_max(file->pos, file->size);
}
@ -1246,7 +1266,6 @@ int lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info) {
return err;
}
// TODO abstract out info assignment
memset(info, 0, sizeof(*info));
info->type = entry.d.type & 0xff;
if (info->type == LFS_TYPE_REG) {
@ -1370,7 +1389,6 @@ int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath) {
}
// fetch again in case newcwd == oldcwd
// TODO handle this better?
err = lfs_dir_fetch(lfs, &oldcwd, oldcwd.pair);
if (err) {
return err;
@ -1569,7 +1587,7 @@ int lfs_unmount(lfs_t *lfs) {
int lfs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data) {
// iterate over metadata pairs
lfs_dir_t dir;
lfs_file_t file;
lfs_entry_t entry;
lfs_block_t cwd[2] = {0, 1};
while (true) {
@ -1586,28 +1604,20 @@ int lfs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data) {
}
// iterate over contents
while ((0x7fffffff & dir.d.size) >= dir.off + sizeof(file.entry.d)) {
while ((0x7fffffff & dir.d.size) >= dir.off + sizeof(entry.d)) {
int err = lfs_bd_read(lfs, dir.pair[0], dir.off,
sizeof(file.entry.d), &file.entry.d);
sizeof(entry.d), &entry.d);
if (err) {
return err;
}
dir.off += file.entry.d.len;
if ((0xf & file.entry.d.type) == LFS_TYPE_REG) {
if (file.entry.d.u.file.size < lfs->cfg->block_size) {
int err = cb(data, file.entry.d.u.file.head);
if (err) {
return err;
}
} else {
int err = lfs_index_traverse(lfs,
file.entry.d.u.file.head,
file.entry.d.u.file.size,
cb, data);
if (err) {
return err;
}
dir.off += entry.d.len;
if ((0xf & entry.d.type) == LFS_TYPE_REG) {
int err = lfs_index_traverse(lfs,
entry.d.u.file.head, entry.d.u.file.size,
cb, data);
if (err) {
return err;
}
}
}

14
lfs.h
View File

@ -55,6 +55,7 @@ enum lfs_open_flags {
LFS_O_TRUNC = 0x080,
LFS_O_APPEND = 0x100,
LFS_O_SYNC = 0x200,
LFS_O_DIRTY = 0x10000,
};
enum lfs_whence_flags {
@ -128,7 +129,6 @@ struct lfs_info {
// littlefs data structures
typedef struct lfs_entry {
lfs_block_t pair[2];
lfs_off_t off;
struct lfs_disk_entry {
@ -145,14 +145,17 @@ typedef struct lfs_entry {
} lfs_entry_t;
typedef struct lfs_file {
struct lfs_entry entry;
int flags;
lfs_block_t pair[2];
lfs_off_t off;
lfs_block_t head;
lfs_size_t size;
uint32_t flags;
lfs_off_t pos;
lfs_off_t wpos;
lfs_block_t wblock;
lfs_off_t woff;
lfs_off_t rpos;
lfs_block_t rblock;
lfs_off_t roff;
} lfs_file_t;
@ -172,7 +175,6 @@ typedef struct lfs_dir {
} lfs_dir_t;
typedef struct lfs_superblock {
lfs_block_t pair[2];
lfs_off_t off;
struct lfs_disk_superblock {

6
tests/test_files.sh
View File

@ -14,10 +14,14 @@ TEST
echo "--- Simple file test ---"
tests/test.py << TEST
lfs_mount(&lfs, &cfg) => 0;
lfs_file_open(&lfs, &file[0], "hello", LFS_O_RDWR | LFS_O_CREAT | LFS_O_APPEND) => 0;
lfs_file_open(&lfs, &file[0], "hello", LFS_O_WRONLY | LFS_O_CREAT) => 0;
size = strlen("Hello World!\n");
memcpy(wbuffer, "Hello World!\n", size);
lfs_file_write(&lfs, &file[0], wbuffer, size) => size;
lfs_file_close(&lfs, &file[0]) => 0;
lfs_file_open(&lfs, &file[0], "hello", LFS_O_RDONLY) => 0;
size = strlen("Hello World!\n");
lfs_file_read(&lfs, &file[0], rbuffer, size) => size;
memcmp(rbuffer, wbuffer, size) => 0;
lfs_file_close(&lfs, &file[0]) => 0;

4
tests/test_seek.sh
View File

@ -211,7 +211,7 @@ tests/test.py << TEST
lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => pos;
lfs_file_write(&lfs, &file[0], buffer, size) => size;
lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => pos;
lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => pos+size;
lfs_file_read(&lfs, &file[0], buffer, size) => size;
memcmp(buffer, "doggodogdog", size) => 0;
@ -254,7 +254,7 @@ tests/test.py << TEST
lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => pos;
lfs_file_write(&lfs, &file[0], buffer, size) => size;
lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => pos;
lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => pos+size;
lfs_file_read(&lfs, &file[0], buffer, size) => size;
memcmp(buffer, "doggodogdog", size) => 0;