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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_interspersed.toml
+17 -17
View File
@@ -24,20 +24,20 @@ code = '''
}
lfs_dir_open(&lfs, &dir, "/") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
for (int j = 0; j < FILES; j++) {
sprintf(path, "%c", alphas[j]);
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, path) == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == SIZE);
}
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_read(&lfs, &dir, &info) => LFS_ERR_NOENT;
lfs_dir_close(&lfs, &dir) => 0;
for (int j = 0; j < FILES; j++) {
@@ -89,17 +89,17 @@ code = '''
lfs_file_close(&lfs, &file);
lfs_dir_open(&lfs, &dir, "/") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "zzz") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == FILES);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_read(&lfs, &dir, &info) => LFS_ERR_NOENT;
lfs_dir_close(&lfs, &dir) => 0;
lfs_file_open(&lfs, &file, "zzz", LFS_O_RDONLY) => 0;
@@ -141,21 +141,21 @@ code = '''
lfs_file_close(&lfs, &files[2]);
lfs_dir_open(&lfs, &dir, "/") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "e") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == SIZE);
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "g") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == SIZE);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_read(&lfs, &dir, &info) => LFS_ERR_NOENT;
lfs_dir_close(&lfs, &dir) => 0;
lfs_file_open(&lfs, &files[0], "e", LFS_O_RDONLY) => 0;
@@ -208,20 +208,20 @@ code = '''
}
lfs_dir_open(&lfs, &dir, "/") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
for (int j = 0; j < FILES; j++) {
sprintf(path, "%c", alphas[j]);
lfs_dir_read(&lfs, &dir, &info) => 1;
lfs_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, path) == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == SIZE);
}
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_read(&lfs, &dir, &info) => LFS_ERR_NOENT;
lfs_dir_close(&lfs, &dir) => 0;
for (int j = 0; j < FILES; j++) {