Rust Host Function - Wasmtime Typing CST Test
Loading…
Rust Host Function — Wasmtime Code
Defines a host function callable from WASM.
# wasmtime/demo/host.rs
use wasmtime::*;
fn main() -> anyhow::Result<()> {
let engine = Engine::default();
let mut store = Store::new(&engine, ());
let func = Func::wrap(&mut store, |x: i32| {
println!("Called with {}", x);
});
let module = Module::from_file(&engine, "host.wasm")?;
let instance = Instance::new(&mut store, &module, &[func.into()])?;
Ok(())
}Wasmtime Language Guide
Wasmtime is a fast, secure, and production-grade WebAssembly runtime built by the Bytecode Alliance. It runs WebAssembly modules outside the browser-on servers, desktops, edge infrastructure, and embedded systems-using WASI for safe system interaction.
Primary Use Cases
- ▸Running Wasm modules in servers or command-line environments
- ▸Embedding sandboxed plugins inside Rust/Go/Python/Node applications
- ▸Serverless compute and microVM-like execution
- ▸Edge compute environments
- ▸Running polyglot Wasm applications via WASI
Notable Features
- ▸WASI (WebAssembly System Interface) support
- ▸JIT via Cranelift compiler
- ▸AOT compilation for low-latency startup
- ▸Secure sandboxing with capability-based design
- ▸Multi-language host embedding APIs
Origin & Creator
Originally created by Mozilla researchers in 2019; now maintained by the Bytecode Alliance (Fastly, Intel, Red Hat, Microsoft, etc.).
Industrial Note
Wasmtime is used heavily in serverless platforms, secure plugin systems, cloud-edge runtimes, and performance-sensitive WASI compute workloads.