wasi_binio_host 和 wasi_binio_wasm

wasi_binio_host 是 wasm_binio 的宿主crate。另一个crate是 wasi_binio_wasm，它用于wasm模块中。它创建了一个call_stub，以便宿主可以调用带有复杂数据结构参数和结果的WebAssembly函数。

截至今天，wasm函数只能接受i32 i64 f32 f64类型。如果你在wasm中有一个像这样的函数：在wasm中： do_compute(point1: &Point, point2: &Point)->Rect {...}没有直接从宿主调用它的方法。借助wasm_binio的帮助，我们也可以调用call_stub函数，并像这样发送参数和结果

宿主中的代码

let result: Rect = call_stub(&instance, &(point1, point2), "do_compute")

wasm中的代码

#[no_mangle]
fn do_compute(ptr:i32, buffer_size: i32)->i64{
   let point_tuple : (Point, Point) = wasi_binio_wasm::wasm_deserialize(ptr, buffer_size).unwrap();
   let rect: Rect = some_how_make_a_rect_from_two_points()... /* Your own logic here */
   wasi_binio_wasm::wasm_serialize(&rect).unwrap()
}
Since wasm and wasi are under active development. Wasi will soon provide complex arguments support.
At the time you find this crate, this feature probably have already been supported natively.