Upstreaming the bare-metal / small-stack work from myers/structured-zstd?

[polaz]

Hi @myers! We came across your fork and the bare-metal work on the zarn-* branches: boxing the FSE sequence tables so a decode fits a 32 KiB stack, staging Raw/RLE block reads through the heap instead of a 128 KiB stack array, and gating the x86 SIMD paths and the encoder for targets without std.

That is exactly the direction we want the crate to go (no_std + alloc, small stacks, embedded and kernel users), and we'd love to have it upstream if you're up for it. A few notes in case they help:

• main now has magicless decoding (FrameDecoder::set_magicless, plus the encoder side), so that part of your branch may no longer be needed. Happy to hear if it misses something your use case relies on.
• main has moved a fair bit since your base, mostly in the sequence decoder. If rebasing is a chore, tell us which changes matter most to you and we can help carry them over.
• Small, separate PRs are easiest to review here, e.g. one for the stack-size changes and one for the no_std gating. A test that pins the stack budget you need would be great, so it doesn't regress later.

It would also be good to hear about your setup: what target and environment you run the decoder in, and which constraints bit you first. That helps us keep it working for you. No pressure at all, and thanks for building on it!

[myers]

Thank you for this crate.

I put out 3 PRs. I am extending Asterinas and needed this to work in the kernel.

Please note I used AI (Opus 5.5) for all of this.

[polaz]

Thanks a lot, Myers! I honestly didn't expect such a quick turnaround, and it's great to see the crate running inside Asterinas.

I need about a day before I can merge. We've just filed the papers to register a non-profit association that will hold this project as open source, and from now on every contribution needs a Contributor License Agreement (CLA). You keep the copyright in your code; the CLA just confirms the project may use and share it. I'm setting up the CLA and a small site for signing it right now, and I'll post the link here as soon as it's live. Signing takes a minute and covers all three PRs.

Thanks again for your patience!