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Changed lfs_dir_read to return 0 on success

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Before:
If an entry is found, lfs_dir_read returns 1
If at end of directory, lfs_dir_read returns 0

After:
If an entry is found, lfs_dir_read returns 0
If at end of directory, lfs_dir_read returns LFS_ERR_NOENT

---

lfs_dir_read is a bit of an odd function. It's supposed to match
lfs_file_read, but instead of reading bytes, it reads directory
entries.

Its POSIX equivalent, readdir, indicates whether or not we reached
the end of the directory by returning a NULL pointer:

struct dirent *readdir(DIR *dirp);

But this API needed to change for littlefs, since we don't use errno,
instead returning errors as signed integers through all API functions,
including lfs_dir_read.  So, in an effort to match lfs_file_read,
lfs_dir_read returned the "number" of directory entries read, limited
to either 0 or 1.

Perhaps unsurprisingly, this turned out to be confusing to users,
and a better API was proposed hathach to instead return either 0
or LFS_ERR_NOENT, an error which can't occur for other reasons in
lfs_dir_read.

Suggested by hathach
This commit is contained in:
Christopher Haster
2020-12-20 18:36:38 -06:00
parent 1a59954ec6
commit e50a0677c0
6 changed files with 366 additions and 364 deletions
Download Patch File Download Diff File Expand all files Collapse all files
tests/test_relocations.toml
+20 -20
View File
@@ -26,14 +26,14 @@ code = '''
}
lfs_dir_open(&lfs, &dir, "child") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_read(&lfs, &dir, &info) => 0;
for (int i = 0; i < COUNT; i++) {
sprintf(path, "test%03d_loooooooooooooooooong_name", i);
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
strcmp(info.name, path) => 0;
}
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_read(&lfs, &dir, &info) => LFS_ERR_NOENT;
lfs_dir_close(&lfs, &dir) => 0;
if (j == ITERATIONS-1) {
@@ -49,14 +49,14 @@ code = '''
lfs_mount(&lfs, &cfg) => 0;
lfs_dir_open(&lfs, &dir, "child") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_read(&lfs, &dir, &info) => 0;
for (int i = 0; i < COUNT; i++) {
sprintf(path, "test%03d_loooooooooooooooooong_name", i);
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
strcmp(info.name, path) => 0;
}
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_read(&lfs, &dir, &info) => LFS_ERR_NOENT;
lfs_dir_close(&lfs, &dir) => 0;
for (int i = 0; i < COUNT; i++) {
sprintf(path, "child/test%03d_loooooooooooooooooong_name", i);
@@ -92,11 +92,11 @@ code = '''
}
lfs_dir_open(&lfs, &dir, "child") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_read(&lfs, &dir, &info) => 0;
for (int i = 0; i < COUNT; i++) {
sprintf(path, "test%03d_loooooooooooooooooong_name", i);
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
strcmp(info.name, path) => 0;
info.size => 0;
@@ -105,14 +105,14 @@ code = '''
lfs_file_write(&lfs, &file, "hi", 2) => 2;
lfs_file_close(&lfs, &file) => 0;
}
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_read(&lfs, &dir, &info) => LFS_ERR_NOENT;
lfs_dir_rewind(&lfs, &dir) => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_read(&lfs, &dir, &info) => 0;
for (int i = 0; i < COUNT; i++) {
sprintf(path, "test%03d_loooooooooooooooooong_name", i);
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
strcmp(info.name, path) => 0;
info.size => 2;
@@ -121,18 +121,18 @@ code = '''
lfs_file_write(&lfs, &file, "hi", 2) => 2;
lfs_file_close(&lfs, &file) => 0;
}
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_read(&lfs, &dir, &info) => LFS_ERR_NOENT;
lfs_dir_rewind(&lfs, &dir) => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_read(&lfs, &dir, &info) => 0;
for (int i = 0; i < COUNT; i++) {
sprintf(path, "test%03d_loooooooooooooooooong_name", i);
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
strcmp(info.name, path) => 0;
info.size => 2;
}
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_read(&lfs, &dir, &info) => LFS_ERR_NOENT;
lfs_dir_close(&lfs, &dir) => 0;
for (int i = 0; i < COUNT; i++) {