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 patch just moves the definition of the wrapper object fat_vfs_open_obj
to the location of the definition of its function, which matches how it's
done in most other places in the code base.
The fat_vfs_ilistdir2() function was only used by fat_vfs_ilistdir_func()
so moving the former into the same file as the latter allows it to be
placed directly into the latter function, thus saving code size.
It's possible to use the methods (eg ilistdir) of a VFS FatFS object
without it being mounted in the VFS itself. This previously worked but
only because FatFS was "mounting" the filesystem automatically when any
function (eg f_opendir) was called. But it didn't work for ports that used
synchronisation objects (_FS_REENTRANT) because they are only initialised
via a call to f_mount. So, call f_mount explicitly when creating a new
FatFS object so that everything is set up correctly. Then also provide a
finaliser to do the f_umount call, but only if synchronisation objects are
enabled (since otherwise the f_umount call does nothing).
This patch simplifies the str creation API to favour the common case of
creating a str object that is not forced to be interned. To force
interning of a new str the new mp_obj_new_str_via_qstr function is added,
and should only be used if warranted.
Apart from simplifying the mp_obj_new_str function (and making it have the
same signature as mp_obj_new_bytes), this patch also reduces code size by a
bit (-16 bytes for bare-arm and roughly -40 bytes on the bare-metal archs).
Header files that are considered internal to the py core and should not
normally be included directly are:
py/nlr.h - internal nlr configuration and declarations
py/bc0.h - contains bytecode macro definitions
py/runtime0.h - contains basic runtime enums
Instead, the top-level header files to include are one of:
py/obj.h - includes runtime0.h and defines everything to use the
mp_obj_t type
py/runtime.h - includes mpstate.h and hence nlr.h, obj.h, runtime0.h,
and defines everything to use the general runtime support functions
Additional, specific headers (eg py/objlist.h) can be included if needed.
VfsFat no longer has the listdir() method. Rather, if listdir()
functionality is needed then one should use uos.listdir() which will call
VfsFat.ilistdir().
Damien George
Andrew Leech
Tom Collins
Andrew Gatt