Christopher Haster e50a0677c0 Changed lfs_dir_read to return 0 on success ...

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

2020-12-24 23:15:02 -06:00

22 KiB

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