Rust bindings

[pac-work]

This is a placeholder for potential integration of bindings for the Rust programing language into the main repository. It has to my knowledge not been decided yet whether this is desirable or not. Let this draft merge request serve the purpose of increasing the visibility of ongoing work until a decision how to progress with this is made.

[pedro-alves-ferreira]

Code-wise, the branch is ready for PR (https://github.com/pac-work/mxl/tree/rust-bindings).

Still, it's missing the integration with GitHub CI.

@cwtchan submitted a PR (pac-work#5) with a proposal for a separate .yml file to build the Rust package. However, it does not run under the same Docker image as the C++ build.
Ideally, we would want the Rust build in the same environment as C++, so I've been trying to use act (https://nektosact.com/) to run the CI locally but, after having dealt with a few hiccups, I still can't get it to work (see below).

@sviengkhou and others: any help is highly appreciated.

|  > [10/13] RUN groupadd --gid "0" "devcontainer"  && useradd --uid "0" --gid "0" -m -s /bin/bash "devcontainer"  && apt-get install -y sudo  && printf '%s ALL=(root) NOPASSWD:ALL\n' "devcontainer" > "/etc/sudoers.d/devcontainer"  && chmod 0440 "/etc/sudoers.d/devcontainer":
| 0.108 groupadd: GID '0' already exists
| ------
| Dockerfile:74
| --------------------
|   73 |     # Create the user
|   74 | >>> RUN groupadd --gid "${USER_GID}" "${USERNAME}" \
|   75 | >>>  && useradd --uid "${USER_UID}" --gid "${USER_GID}" -m -s /bin/bash "${USERNAME}" \
|   76 | >>>  && apt-get install -y sudo \
|   77 | >>>  && printf '%s ALL=(root) NOPASSWD:ALL\n' "${USERNAME}" > "/etc/sudoers.d/${USERNAME}" \
|   78 | >>>  && chmod 0440 "/etc/sudoers.d/${USERNAME}"
|   79 |     
| --------------------
| ERROR: failed to build: failed to solve: process "/bin/sh -c groupadd --gid \"${USER_GID}\" \"${USERNAME}\"  && useradd --uid \"${USER_UID}\" --gid \"${USER_GID}\" -m -s /bin/bash \"${USERNAME}\"  && apt-get install -y sudo  && printf '%s ALL=(root) NOPASSWD:ALL\\n' \"${USERNAME}\" > \"/etc/sudoers.d/${USERNAME}\"  && chmod 0440 \"/etc/sudoers.d/${USERNAME}\"" did not complete successfully: exit code: 4

For some reason USER_GID is expanding to 0.

[felixpou]

previous comment is from TSC 2025-08-07

• @sviengkhou proposed to help @pedro-alves-ferreira

[sviengkhou]

@pedro-alves-ferreira can you share your "act" .env file or the "act" command you are using to launch your local github action?

[pedro-alves-ferreira]

Hi Sithi, Thanks for getting back to me on this. I managed to progress a bit more with act but then I got stuck on another step. I'm on vacation until the 19th. I'll get back to you when I'm back. Thanks! Enviado de Outlook para Android<https://aka.ms/AAb9ysg>

…

________________________________ From: sviengkhou ***@***.***> Sent: Thursday, August 14, 2025 3:48:09 PM To: dmf-mxl/mxl ***@***.***> Cc: Pedro Ferreira ***@***.***>; Mention ***@***.***> Subject: Re: [dmf-mxl/mxl] Draft: Rust bindings (PR #29) [https://avatars.githubusercontent.com/u/15689660?s=20&v=4]sviengkhou left a comment (dmf-mxl/mxl#29)<#29 (comment)> @pedro-alves-ferreira<https://github.com/pedro-alves-ferreira> can you share your "act" .env file or the "act" command you are using to launch your local github action? — Reply to this email directly, view it on GitHub<#29 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AEZI3QDJEKSCGA7SVYWNOZL3NTRXTAVCNFSM6AAAAACAZ3SBTSVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTCOBZGY4DKNRWGU>. You are receiving this because you were mentioned.Message ID: ***@***.***>

[pedro-alves-ferreira]

Hi @sviengkhou! I'm back. When you have some time to go over this, please ping me on Slack. Thanks!

[mlefebvre1]

Is it ready to be properly reviewed or is it still in draft mode waiting for some decisions? I have Rust experience, and I would like to review whenever this is ready.

[pac-work]

Is it ready to be properly reviewed or is it still in draft mode waiting for some decisions? I have Rust experience, and I would like to review whenever this is ready.

Hello @mlefebvre1, thanks for the offer and sorry for late response (IBC and stuff...).

It would be great if you can start taking a look at this. It is capable of reading and writing both audio and video, but it is far from providing the full spectrum of the C API. There are some TODOs which probably should be done before merging (like defining a strong type for timestamp), but overall, it shows where this is heading.

Nothing is set in stone, please take it with a grain of salt and look mostly for "this has to change before this can get merged".

In the future, we have hoped for async API to come, but that is really far away at this point.

[mlefebvre1]

Overall looks good, there's some clippy warnings here and there you will have to solve.

[jonasohland]

I personally like using fields to record the error separately from the message like this:

tracing::error!(error = %err, "Failed to release MXL flow reader.")

It makes analysis of large amounts of logs a bit easier if you are set up for structured logging, but that is personal preference.

[jonasohland]

If I myself am a user of the tracing library, I may not want to have all tracing events to also be emitted as log records. I would suggest to expose this as an optional feature of this library:

[features]
tracing-log = ["tracing/log"]

For this to work, this dependency needs to be moved to the mxl crates Cargo.toml