On ports like unix where the Epoch is 1970/1/1 and atime/mtime/ctime are in
seconds since the Epoch, this value will overflow a small-int on 32-bit
systems. So far this is only an issue on 32-bit unix builds that use the
VFS layer (eg dev and coverage unix variants) but the fix (using
mp_obj_new_int_from_uint instead of MP_OBJ_NEW_SMALL_INT) is there for all
ports so as to not complicate the code, and because they will need the
range one day.
Also apply a similar fix to other fields in VfsPosix.stat because they may
also be large.
Signed-off-by: Damien George <damien@micropython.org>
https://www.python.org/dev/peps/pep-0475/
This implements something similar to PEP 475 on the unix port, and for the
VfsPosix class.
There are a few differences from the CPython implementation:
- Since we call mp_handle_pending() between any ENITR's, additional
functions could be called if MICROPY_ENABLE_SCHEDULER is enabled, not
just signal handlers.
- CPython only handles signal on the main thread, so other threads will
raise InterruptedError instead of retrying. On MicroPython,
mp_handle_pending() will currently raise exceptions on any thread.
A new macro MP_HAL_RETRY_SYSCALL is introduced to reduce duplicated code
and ensure that all instances behave the same. This will also allow other
ports that use POSIX-like system calls (and use, eg, VfsPosix) to provide
their own implementation if needed.
Following other C-level protocols, this VFS protocol is added to help
abstract away implementation details of the underlying VFS in an efficient
way. As a starting point, the import_stat function is put into this
protocol so that the VFS sub-system does not need to know about every VFS
implementation in order to do an efficient stat for importing files.
In the future it might be worth adding other functions to this protocol.
This VFS component allows to mount a host POSIX filesystem within the uPy
VFS sub-system. All traditional POSIX file access then goes through the
VFS, allowing to sandbox a uPy process to a certain sub-dir of the host
system, as well as mount other filesystem types alongside the host
filesystem.
Damien George
David Lechner
Damien George
Bob Fanger