wasi-sdk VS workers-rs

I would really love being able to take any POSIX command line tool, compile that to WASI, and run it on (at least) Linux, Windows and macOS like a regular executable without having to install a separate WASI runtime.

I'm a 'WASI convert' since I was able to take an ancient 8-bit assembler written in the mid-90's (http://xi6.com/projects/asmx/), compile that as-is with the WASI SDK (https://github.com/WebAssembly/wasi-sdk), and then integrate it into a VSCode extension (https://marketplace.visualstudio.com/items?itemName=floooh.v...).

A similar problem is I have is a shader cross-compiler (https://github.com/floooh/sokol-tools) which needs to run Linux, macOS and Windows and takes too long to build locally, thus I currently need to distribute that as pre-built binaries. Compiling this to WASI works, but the filesystem access restrictions built into current wasm runtimes are a hassle to manage, and it would require a WASI runtime to be separately installed).

There is the WASI SDK if you want to target WASI from C/C++:

https://github.com/WebAssembly/wasi-sdk

It may not have all the amenities of Emscripten, but it's way less bulky.

The most direct way to debug WebAssembly is through the WebAssembly System Interface (WASI). In itk-wasm, we can build to WASI with the WASI SDK by specifying the itkwasm/wasi toolchain image. A backtrace can quickly be obtained with the itk-wasm CLI. Or, a fully fledged debugger session can be started with LLDB.

We use the add_executable command to build executables with itk-wasm. The Emscripten and WASI toolchains along with itk-wasm build and execution configurations are contained in itk-wasm dockcross Docker images invoked by the itk-wasm command line interface (CLI). Note that the same code can also be built and tested with native operating system toolchains. This is useful for development and debugging.

A more lightweight tool than emscripten is the WASI SDK (https://github.com/WebAssembly/wasi-sdk/releases). However, it doesn't generate JS or HTML.

wget https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-16/wasi-sdk-16.0-macos.tar.gz

First, we’ll download the wasi-sdk. We’ll use wasi-sdk-16.0-linux.tar.gz, the latest version available when writing this article. We’ll move the file to the /opt directory and unpack it as follows:

I'm intrigued. Pretty good write-up about it here. One would need an ebuild for wasi-libc and an ebuild for wasi-sdk.

The previously mentioned PR for wasm32-unknown-unknown compatibility solved this by including libc .c files from OpenBSD. My go to solution is different though. I prefer to build using the wasi-sdk (a WASI-enabled WebAssembly C/C++ toolchain).

There's also the https://github.com/WebAssembly/wasi-sdk repo which is kind of a meta-build-system for all this.

But in FreeBSD we build all the pieces directly, here's our build recipes (with some hacks due to llvm's cmake code being stupid sometimes):

compiler-rt (from llvm): https://github.com/freebsd/freebsd-ports/blob/main/devel/was...

libc (from what you linked): https://github.com/freebsd/freebsd-ports/blob/main/devel/was...

libc++ (from llvm): https://github.com/freebsd/freebsd-ports/blob/main/devel/was...

- The speed of the Python interpreter running in WebAssembly

Today, Python cold starts are slower than cold starts for a JavaScript Worker of equivalent size. A basic "Hello World" Worker written in JavaScript has a near zero cold start time, while a Python Worker has a cold start under 1 second.

That's because we still need to load Pyodide into your Worker on-demand when a request comes in. The blog post describes what we're working on to reduce this — making Pyodide already available upfront.

Once a Python Worker has gone through a cold start though, the differences are more on the margins — maybe a handful milliseconds, depending on what happens during the request.

- There is a slight cost (think — microseconds not milliseconds) to crossing the "bridge" between JavaScript and WebAssembly — for example, by performing I/O or async operations. This difference tends to be minimal — generally something measured in microseconds not milliseconds. People with performance sensitive Workers already write them in Rust https://github.com/cloudflare/workers-rs, which also relies on bridging between JavaScript and WebAssembly.

- The Python interpreter that Pyodide provides, that runs in WebAssembly, isn't as fast as the years and years of optimization that have gone into making JavaScript fast in V8. But it's still relatively early days for Pyodide, compared to the JS engine in V8 — there are parts of its code where we think there are big perf gains to be had. We're looking forward to upstreaming performance improvements, and there are WebAssembly proposals that help here too.

Not yet, but we're working on that https://github.com/cloudflare/workers-rs/pull/324

I'm also in the Workers org but I have had a bit of interaction with Rust. There's some Rust in the Workers runtime using lol-html for HTMLRewriter as well as some tooling and there's the full blown workers-rs framework that I work on, but that's about it for the Rust I work on regularly.

I'm an engineer at Cloudflare working on Workers (and a maintainer of workers-rs) and I'd love to help whoever ends up maintaining this get that PR rewriting it in Rust across the line.

GitHub - cloudflare/workers-rs: Write Cloudflare Workers in 100% Rust via WebAssembly

I never said it was, but thankfully nowadays there are plenty of other tools that are fast enough to keep the dev cycle quick. Personally esbuild is my go-to when I need a bundler but I've grown really fond of SWC native api, we used to use it at work for our wasm build tool for our workers-rs framework.

There's actually a rust framework for Workers https://github.com/cloudflare/workers-rs

I'm a maintainer of the of the Cloudflare workers-rs project to allow you to write serverless functions in Rust running as WASM in our V8-based runtime. There's certainly some rough spots (doesn't have complete parity with our default JS runtime apis), but if you're concerned with cold start times and you don't need a full containerized environment I think it's a solid choice.

Most likely, it should, we just haven't had the time to fully implement it or add a library to wrap the FFI. Please let us know you need a feature by opening an issue.

I may be biased, as the original project author, but I’d recommend using Cloudflare Workers https://github.com/cloudflare/workers-rs - totally free their with very generous limits.