wasmtime-ruby

Wasmtime WebAssembly runtime in Ruby

## Introduction This project allows you to use the [Wasmtime](https://wasmtime.dev/) WebAssembly runtime from within your Ruby project. Why would you want that? [WebAssembly](https://webassembly.org/) (or WASM) is a technology that allows you to write programs that run at near-native speeds in a safe sandboxed environment. Wasmtime is a runtime that allows you to execute WASM programs. This gem embeds Wasmtime within a native extension so you can execute a WASM program from Ruby. This project is pretty experimental and not production ready right now. There are quite a few things that aren't built yet, see [TODO](#todo) section below. **Note:** [WebAssembly Interface Types](https://github.com/WebAssembly/interface-types/blob/master/proposals/interface-types/Explainer.md) support has been [temporarily removed](https://github.com/bytecodealliance/wasmtime/pull/1292) from Wasmtime. Therefore, only 32 and 64-bit integers and floats are currently supported. ## Usage Install the `wasmtime` gem. Compiling the native extension requires [Rust](https://rustup.rs/). ```sh gem install wasmtime ``` Given a you have WASM module in your current directory, such as the example `fibonacci.wasm` built from [here](https://github.com/dtcristo/wasmtime-ruby/tree/master/wasm/fibonacci). First `require 'wasmtime/require'` to activate the Wasmtime require patch, allowing you to require any `*.wasm` module as if it were a Ruby file. Doing so will internally create a `Wasmtime::Instance` and define a Ruby module with functions for each export. Finally, invoke the `fib` export like so. ```rb require 'wasmtime/require' require_relative 'fibonacci' puts Fibonacci.fib(11) #=> 89 ``` If you don't like all the magic in the example above, you can do the same without the require patch. If your project is going to be a dependency of others use this approach too. ```rb require 'wasmtime' instance = Wasmtime::Instance.new('fibonacci.wasm') puts instance.funcs[:fib].call(11) #=> 89 ``` ## Development Install Ruby dependencies. ```sh bundle install ``` Compile Rust native extension. ```sh rake compile ``` Run test suite. ```sh rake spec ``` Format source code. ```sh rake format ``` ## TODO - Add support for raw memory access and other types of exports - Add support for imports - Implement more of the Wasmtime API - Add benchmarks for WASM program against ones in pure Ruby and true native - Add support for WASM Interface Types when they are supported in Wasmtime