This will always have the maximum/minimum size of a mp_obj_type_t
representation and can be used as a member in other structs.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
The buffer protocol type only has a single member, and this existing layout
creates problems for the upcoming split/slot-index mp_obj_type_t layout
optimisations.
If we need to make the buffer protocol more sophisticated in the future
either we can rely on the mp_obj_type_t optimisations to just add
additional slots to mp_obj_type_t or re-visit the buffer protocol then.
This change is a no-op in terms of generated code.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
For ports that have a system malloc which is not garbage collected (eg
unix, esp32), the stream object for the DB must be retained separately to
prevent it from being reclaimed by the MicroPython GC (because the
berkeley-db library uses malloc to allocate the DB structure which stores
the only reference to the stream).
Although in some cases the user code will explicitly retain a reference to
the underlying stream because it needs to call close() on it, this is not
always the case, eg in cases where the DB is intended to live forever.
Fixes issue #5940.
