Support Python 3.13 (upb)

[liujianwish]

Hi,

There is an performance issue in protobuf when I switching python version from 3.10 to 3.13. Performance droped 20x comparing with 3.10. After some investigating, I find the root cause is due to the backend implmentation of the protobuf. In 3.13, the backend implementation is python, compatible version I guess.

Is there any release plan for supporting python 3.13 (upb ver) or any temp solution to build a upb for python 3.13?

Frank

[shaod2]

Hi, thanks for reporting the performance issue.

Do you have examples / evidence of the performance drop, considering Protobuf backend, in details?

[liujianwish]

Hi, thanks for reporting the performance issue.

Do you have examples / evidence of the performance drop, considering Protobuf backend, in details?

Hi @shaod2 , thanks for your rapid reply.

I have made a demo test as below:

Lib dependency: protobuf==5.29.3

Environment: Linux 5.15.0-78-generic #85-Ubuntu SMP Fri Jul 7 15:25:09 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

Python version: 3.13.12 vs 3.13.1t

Command: python test.py

Test results:

I have attached all the test code as below:

demo.tar.gz

Frank

[davidfritzsche]

@liujianwish Do you use the regular 3.13.1 or the experimental free-threaded 3.13.1t (see https://docs.python.org/3/whatsnew/3.13.html#free-threaded-cpython)?
It seems to me that the upb-based protobuf package does not support free threaded Python at the moment, at least there are no wheels for free-threaded Python on pypi.org, i.e., on a free-threaded Python you would get the Python-only wheel.

[liujianwish]

@liujianwish Do you use the regular 3.13.1 or the experimental free-threaded 3.13.1t (see https://docs.python.org/3/whatsnew/3.13.html#free-threaded-cpython)? It seems to me that the upb-based protobuf package does not support free threaded Python at the moment, at least there are no wheels for free-threaded Python on pypi.org, i.e., on a free-threaded Python you would get the Python-only wheel.

Thanks for your clearification. I am researching on free threaded version python (3.13t).

As upb has moved into protobuf, is there any release plan to support python 3.13t?