[Python-3000] Revised PEP for buffer protocol (original) (raw)

Josiah Carlson jcarlson at uci.edu
Wed Mar 21 00:14:33 CET 2007

Nick Coghlan <ncoghlan at gmail.com> wrote:

Josiah Carlson wrote: > "Travis E. Oliphant" <oliphant.travis at ieee.org> wrote: >> The buffer interface should allow discontiguous memory areas to >> share standard striding information. However, consumers that do >> not want to deal with strided memory should also be able to >> request a contiguous segment easily. > > I don't believe this is necessary. While the point of the buffer > interface is to offer direct access to memory regions of an object or > structure, being able to ask "can I get a contiguous segment" isn't > really reasonable. The response is either going to be "yes, that's how I > represent it anyways" or "no, that's not how I represent the data". But > this bit of meta information is easily acquired by getting the buffer > and checking the stride.

I think the point is for there to be something in the standard library or Python core that makes it easy for a consumer to copy the data to a contiguous memory segment in the event the consumer can't directly handle non-contiguous data (e.g. a C API function that takes the source object, a pointer to the destination memory block, and an optional slice object defining a subsection of the memory block to be retrieved)

But that still isn't a use-case for the "I want a contiguous view". The consumer needs to construct a memory region, copy the non-contiguous data, then pass it on somewhere else. The object offering the original view shouldn't need to offer anything special to make it happen.

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