Migrate from bencoder.pyx

[roshii]

bencoder.pyx was not updated for 6 years now, and preventing py3.13 compatibility.

I suggest we migrate from it. Some options.

• bencode.py: pure-python
• bencode2: "fast enough, written with c++ in CPython"
• fastbencode: pure-python with optional rust bindings

At this point i'd favor the later.

Ref. #1802 (comment)_

[3nprob]

I'd prefer a pure-python replacement. The simpler, smaller, and less third-party deps the better. Performance doesn't seem that important even for embedded users.

• bencode.py: pure-python

Note that the actual bencode implementation here comes from https://pypi.org/project/bencodepy/, with its source repo on github currently 404ing. Not good.

• bencode2: "fast enough, written with c++ in CPython"
• fastbencode: pure-python with optional rust bindings

Between the presented options, fastbencode seems like the way to go (assuming rust compilation isn't actually needed for the jm use-case)

[3nprob]

One complication with fastbencode is that it dropped Python 3.8 support in the same release that it fixed Python3.13 compatibility (https://github.com/breezy-team/fastbencode/releases/tag/v0.3.2).

So adopting it would mean breaking Python 3.8 support for JoinMarket, too. I guess the major consideration I can think of there would be users on Ubuntu 20.04 and (to a lesser extent) Debian 10 using dist python (which is still 3.8 for both).

[roshii]

I'd suggest first dropping python 3.8 support, official eol for a year now. The implicated end of compatibility with ubuntu 20.04 or debian 10 should not matter much either with these being eol since april and june this year, futhermore alternatives python version can always be installed.

Off course, there may be other library than the ones i mentioned, it was not exhaustive.

[roshii]

Note that the actual bencode implementation here comes from https://pypi.org/project/bencodepy/, with its source repo on github currently 404ing. Not good.

Not good indeed. Lets forget this one.

Between the presented options, fastbencode seems like the way to go (assuming rust compilation isn't actually needed for the jm use-case)

Rust compilation would be nice, but optional indeed.

[overcoin]

I'd suggest even bigger change. Why not change the package manager?

uv is a high-performance Python package and project manager written in Rust. With uv, you can replace a wide range of traditional tools in your workflow, such as:
pip for installing packages.
pip-tools for dependency locking.
virtualenv/venv for environment management.
pyenv for managing Python versions.
pipx for installing CLI tools.
poetry for project configuration and publishing.
twine for distributing packages.
Thanks to its Rust-based roots, uv performs operations 10-100 times faster than these traditional Python tools, and this increase in speed is noticeable even in small projects.

You can also require that a specific version of Python is used:
uv venv --python 3.12
If the version isn't already installed, uv will fetch and install it for you automatically.

[3nprob]

I'd suggest even bigger change. Why not change the package manager?

I believe that changing the packaging and build tooling is unrelated to addressing the bencoder.pyx issue?

[roshii]

I agree with the idea to migrate to uv, but this is indeed a different story that will not address bencoder.pyx issue.

[overcoin]

I believe that changing the packaging and build tooling is unrelated to addressing the bencoder.pyx issue?

I see no room for hesitation. My choice is definitely fastbencode.