58 lines
1.9 KiB
Rust
58 lines
1.9 KiB
Rust
extern crate core;
|
|
|
|
use anyhow::Result;
|
|
use wasmtime::*;
|
|
|
|
// #[wasm_bindgen]
|
|
// extern {
|
|
// pub fn alert(s: &str);
|
|
// }
|
|
//
|
|
// #[wasm_bindgen]
|
|
// pub fn greet(name: &str) {
|
|
// alert(&format!("Hello, {}!", name));
|
|
// }
|
|
fn main() -> Result<()> {
|
|
// Modules can be compiled through either the text or binary format
|
|
let engine = Engine::default();
|
|
let wasm = std::fs::read("./examples/hello_wasm_bg.wasm").unwrap();
|
|
let module = Module::new(&engine, wasm)?;
|
|
|
|
let mut linker = Linker::new(&engine);
|
|
linker.func_wrap("./hello_wasm.js", "__wbg_alert_a5a2f68cc09adc6e", |caller: Caller<'_, u32>, param: i32, param2: i32| {
|
|
let mut caller = caller;
|
|
if let Extern::Memory(memory) = caller.get_export("memory").unwrap() {
|
|
let mut buffer = vec![0; param2 as usize];
|
|
memory.read(caller.as_context(), param as usize, &mut buffer).expect("read mem error");
|
|
let s = String::from_utf8_lossy(&buffer).to_string();
|
|
println!("[alert]: {}", s);
|
|
} else {
|
|
panic!("Should happen, got non memory");
|
|
}
|
|
})?;
|
|
|
|
// All wasm objects operate within the context of a "store". Each
|
|
// `Store` has a type parameter to store host-specific data, which in
|
|
// this case we're using `4` for.
|
|
let mut store = Store::new(&engine, 0);
|
|
let instance = linker.instantiate(&mut store, &module)?;
|
|
|
|
let memory = instance.get_memory(&mut store, "memory")
|
|
.ok_or_else(|| anyhow::format_err!("failed to find `memory` export"))?;
|
|
|
|
let msg = "hatter".as_bytes();
|
|
|
|
let malloc = instance.get_typed_func::<i32, i32, _>(&mut store, "__wbindgen_malloc")?;
|
|
let p = malloc.call(&mut store, msg.len() as i32)?;
|
|
|
|
memory.write(&mut store, p as usize, msg)?;
|
|
|
|
let hello = instance.get_typed_func::<(i32, i32), (), _>(&mut store, "greet")?;
|
|
|
|
// And finally we can call the wasm!
|
|
hello.call(&mut store, (p, msg.len() as i32))?;
|
|
|
|
Ok(())
|
|
}
|
|
|