Stefan Behnel <stefan...@behnel.de> wrote: > > http://docs.python.org/dev/c-api/buffer.html#Py_buffer > > http://docs.python.org/dev/c-api/typeobj.html#buffer-object-structures > > > > Since the Py_buffer.obj filed was undocumented in 3.2, I think we're within > > out rights to restrict the field to the exporter. > > Careful. There are tons of code out there that use the buffer interface, > and the "obj" field has been the way to handle the buffer release ever > since the interface actually worked (somewhere around the release of Py3.0, > IIRC). > > Personally, I never read the documentation above (which was written way > after the design and implementation of the buffer interface).
The documentation has been largely re-written for 3.3. > looked at the (outdated) PEP, and then switched to reading the code once it > started to divert substantially from the PEP. I'm sure there are many users > out there who have never seen the second link above, and still some who > aren't aware that the "exporting object" in the first link is required to > be identical with the one that "__getbuffer__()" was called on. Just think > of an object that acts as a fa??ade to different buffers. That's exactly what the ndarray test object from Modules/_testbuffer.c can do. You can push new buffers onto a linked list and present different ones to each consumer. [Note that IMO that's a questionable design, but it's a test object.] The recommended way of keeping track of resources is to use Py_buffer.internal. I think that part is also appropriately mentioned in the original PEP, though I can perfectly understand if someone misses it due to the huge amount of information that needs to be absorbed. > it's still not all that unlikely that it breaks user code (assuming that it > currently works). The decision to enforce this restriction should not be > taken lightly. As I said, user code using the (also undocumented) Py_buffer.smalltable will also be broken. Stefan Krah _______________________________________________ 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
