Vorpal

joined 2 years ago
[–] Vorpal@programming.dev 3 points 10 months ago

The standard library does have some specialisation internally for certain iterators and collection combinations. Not sure if it will optimise that one specifically, but Vec::into_iter().collect::<Vec>() is optimised (it may look silly, but it comes up with functions returning impl Iterator

[–] Vorpal@programming.dev 2 points 10 months ago* (last edited 10 months ago)

Hm, that is a fair point. Perhaps it would make sense to produce a table of checks: indicate which checks each dependency fails/passes, and then colour code them with severity.

Some experimentation on real world code is probably needed. I plan to try this tool on my own projects soon (after I manually verified that your crate match your git code (hah! Bootstrap problem), I already reviewed your code on github and it seemed to do what it claims).

[–] Vorpal@programming.dev 3 points 10 months ago (2 children)

Yes, obviously there are more ways to hide malicious code.

As for the git commit ID, I didn't see you using it even when it was available though? But perhaps that could be a weakness, if the commit ID used does not match the tag in the repo, that would be a red flag too. That could be worth checking.

[–] Vorpal@programming.dev 7 points 10 months ago (4 children)

Due to the recent xz trouble I presume? Good idea, I was thinking about this on an ecosystem wise scale (e.g. all of crates.io or all of a Linux distro) which is a much harder problem to solve.

Not sure if the tag logic is needed though. I thought cargo embedded the commit ID in the published package?

Also I'm amazed that the name cargo-goggles was available.

[–] Vorpal@programming.dev 0 points 11 months ago (1 children)

Please, send an email to lwn@lwn.net to report this issue to them, they usually fix things quickly.

[–] Vorpal@programming.dev 2 points 11 months ago

Sure, but my point was that such a C ABI is a pain. There are some crates that help:

  • Rust-C++: cxx and autocxx
  • Rust-Rust: stabby or abi_stable

But without those and just plain bindgen it is a pain to transfer any types that can't easily just be repr(C), and there are quite a few such types. Enums with data for example. Or anything using the built in collections (HashMap, etc) or any other complex type you don't have direct control over yourself.

So my point still stands. FFI with just bindgen/cbindgen is a pain, and lack of stable ABI means you need to use FFI between rust and rust (when loading dynamically).

In fact FFI is a pain in most languages (apart from C itself where it is business as usual... oh wait that is the same as pain, never mind) since you are limited to the lowest common denominator for types except in a few specific cases.

[–] Vorpal@programming.dev 1 points 11 months ago (2 children)

Yes, rust is that much of a pain in this case, since you can only safely pass plain C compatible types across the plugin boundary.

One reason is that rust doesn't have stable layouts of structs and enums, the compiler is free to optimise the to avoid padding by reordering, decide which parts to use as niches for Options etc. And yes, that changes every now and then as the devs come up with new optimisations. I think it changes most recently last summer.

[–] Vorpal@programming.dev 1 points 11 months ago* (last edited 11 months ago)

So there is a couple of options for plugins in Rust (and I haven't tried any of them, yet):

  • Wasm, supposedly https://extism.org/ makes this less painful.
  • libloading + C ABI
  • One of the two stable ABI crates (stabby or abi_stable) + libloading
  • If you want to build them into your code base but not have to update a central list there is linkme and inventory.
  • An embedded scripting language might also be a (very different) option. Something like mlua, rhai or rune.

I don't know if any of these suit your needs, but at least you now have some things to investigate further.

[–] Vorpal@programming.dev 6 points 11 months ago* (last edited 11 months ago) (1 children)

Sounds interesting! As I don't know restic that this is apparently based on, what are the differentiating factors between them? While I'm always on board for a rewrite in Rust in general, I'm curious as to if there is anything more to it than that.

EDIT: seems this is already answered in the FAQ, my bad.

[–] Vorpal@programming.dev 14 points 11 months ago

I have read it, it is a very good book, and the memory ordering and atomics sections are also applicable to C and C++ since all of these languages use the same memory ordering model.

Can strongly recommend it if you want to do any low level concurrency (which I do in my C++ day job). I recommended it to my colleagues too whenever they had occasion to look at such code.

I do wish there was a bit more on more obscure and advanced patterns though. Things like RCU, seqlocks etc basically get an honorable mention in chapter 10.

[–] Vorpal@programming.dev 8 points 1 year ago* (last edited 1 year ago) (1 children)

Yes, Sweden really screwed up the first attempt at switching to Gregorian calendar. But there were also multiple countries who switched back and forth a couple of times. Or Switzerland where each administrative region switched separately.

But I think we in Sweden still "win" for worst screw up. Also, there is no good way to handle these dates without specific reference to precise location and which calender they refer to (timestamps will be ambiguous when switching back to Julian calendar).

[–] Vorpal@programming.dev 2 points 1 year ago

I would go with the Arch specific https://aur.archlinux.org/packages/aconfmgr-git instead of ansible, since it can save current system state as well. I use it and love it. See another reply on this post for a slightly deeper discussion on it.

 

cross-posted from: https://programming.dev/post/10657765

I made a replacement for the venerable paccheck. It checks if files managed by the package manger have changed and if so reports that back to the user. Unlike paccheck it is cross distro (supports Debian too and could be further extended), and it uses all your CPU cores to be as fast as possible.

Oh and it is written in Rust (that may be a plus or minus depending on your opinion, but it wouldn't have happened at all in any language except Rust, and Rust makes it very easy to add this sort of parallelism).

There are more details (including benchmarks) in the readme on github. Maybe it is useful to some of you.

(The main goal of this project is not actually the program produced so far, but to continue building this into a library. I have a larger project in the planning phase that needs this (in library form) as part of it.)

 

This is a Rust replacement for debsums (on Debian/Ubuntu/...) and paccheck (on Arch Linux and derivatives). It is much faster than those thanks to using all your CPU cores in parallel. What it does is check files installed by your package manager for changes and reports those on stdout.

This is a project I have been working on over the past few weeks. There are more details (including benchmarks) in the readme.

I normally don't advertise my open source projects (having users other than yourself is both a blessing and a curse), but since there was recent discussion on how to grow this lemmy group I'd thought I'd post it. Maybe it is useful to some of you.

I also spent quite some time on optimising this (including a lot of benchmarking, profiling and trying alternative solutions). In the end I'm happy with the performance, though I am considering io-uring for disk IO.

The main goal of this project is not actually the program produced so far, but to continue building this into a library (currently very little is exposed as pub, because the API will change). I have a larger project in the planning phase that needs this (in library form) as part of it.

 

I'm not affiliated with the site, but I found this interesting. Especially the quite nuanced discussion about if rust is hard or not.

With my background in systems level safety critical hard realtime C++ (plus a bunch of functional programming as a hobby) I feel that the answer was no (for me personally). Basically learn about lifetimes and borrowing and then learn the syntax, done. (Async and unsafe are arguably harder, but again I had the requisite background for it to be mostly familiar, though haven't needed to write much unsafe yet.)

But it was very interesting hearing the other perspective as well! Why rust might feel hard if you have a background in JS/Python/Go etc.

And it was awesome to hear such a nuanced discussion on the Internet, that is truly a rare thing these days.

 

cross-posted from: https://programming.dev/post/1825728

Lots of new features!

Thought I should share this with those who don't use users.rust-lang.org. Note: I'm not affiliated with lib.rs, I'm only reposting to lemmy.

 

Lots of new features!

Thought I should share this with those who don't use users.rust-lang.org. Note: I'm not affiliated with lib.rs, I'm only reposting to lemmy.

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