Re: [Libguestfs] [libnbd PATCH] python: Accept buffers in nbd.Buffer.from_bytearray()
On Thu, May 26, 2022 at 09:16:18AM +0100, Richard W.M. Jones wrote:
...
> But Python already has a handy way to convert any object that
supports
> the buffer interface into a bytearray. Using it, we can now support
> many more parameters; passing in b"1"*9 now correctly creates a 9-byte
> buffer rather than failing. And the error message for a non-buffer
> also improves:
>
> $ ./run nbdsh -c 'nbd.Buffer.from_bytearray(h)'
> Traceback (most recent call last):
> ...
> File "/home/eblake/libnbd/python/nbd.py", line 132, in from_bytearray
> o = libnbdmod.aio_buffer_from_bytearray(ba)
> TypeError: cannot convert 'NBD' object to bytearray
>
> (A reliable TypeError is always better than an unexpected MemoryError
> or segfault).
> ---
Reviewed-by: Richard W.M. Jones <rjones(a)redhat.com>
Thanks!
Now in as commit d477f7c, after also adjusting python unit test 580 to
cover some of the now-permitted cases. There's still probably some
efficiency gains to be had by reworking our aio buffers to use
Python's memoryview objects for zero-copy where possible (similar to
the work we did for Go in 7f5767e3), but that will require a Python
API change and more work, so I'm not tackling it in the short term.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
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