On 11/1/06, "Martin v. Löwis" <[EMAIL PROTECTED]> wrote: > That's also an interesting issue for the datatypes PEP: are datatype > objects meant to be immutable? > That's a question for Travis, but I would think that they would be immutable at the Python level, but mutable at the C level. In Travis' approach array size is not stored in the datatype, so I don't see much need to modify datatype objects in-place. It may be reasonable to allow adding fields to a record, but I don't have enough experience with that to comment.
> This is particularly interesting for the extended buffer protocol: > how long can one keep the data you get from bt_getarrayinfo? > I think your question is limited to shape and strides outputs because dataformat is a reference counted PyObject (and PEP should specify whether it is a borrowed reference). And the answer is the same as for the data from bf_getreadbuffer/bf_getwritebuffer . AFAIK, existing buffer protocol does not answer this question delegating it to the extension module writers who provide objects exporting their buffers. > Also, how does the memory management work for the results? I think it is implied that all pointers are borrowed references. I could not find any discussion of memory management in the current buffer protocol documentation. This is a good question. It may be the case that the shape or stride information is not available as Py_intptr_t array inside the object that wants to export its memory buffer. This is not theoretical, I have a 64-bit application that uses objects that keep their size information in a 32-bit int. BTW, I think the memory management issues with the buffer objects have been resolved at some point. Any lessons to learn from that? _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
