WasmEdge Hyper Demo

In this project, we demonstrate how to use hyper and tokio to build async http client in WebAssembly and execute it using WasmEdge.

Why tokio in WasmEdge?

There are growing demands to perform network requests in WASM and cloud computing. But it would be inefficient to perform network requests synchronously so we need async in WASM.

As tokio is widely accepted, we can bring many projects that depend on tokio to WASM if we can port tokio into WASM. After that, the developers can have async functions in WASM as well as efficient programs.

With the help of tokio support of WasmEdge, the developers can compile the projects that use tokio into WASM and execute it using WasmEdge.

Prequsites

We need install rust and wasm target first.

# install rust 
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

# install wasm target 
rustup target add wasm32-wasi

Then install the WasmEdge. You will need all extensions to run the HTTP server with Tensorflow example.

curl -sSf https://raw.githubusercontent.com/WasmEdge/WasmEdge/master/utils/install.sh | bash -s -- -e all

Add dependencies in Cargo.toml

In this project, we add tokio and reqwest as dependencies.

[dependencies]
hyper_wasi = { version = "0.15", features = ["full"]}
tokio_wasi = { version = "1.21", features = ["rt", "macros", "net", "time", "io-util"]}

Examples

FAQ

use of unstable library feature 'wasi_ext'

If you are using rustc 1.64, you may encounter this error. There are two options:

Update rustc to newer version. Validated versions are 1.65 and 1.59.
Add #![feature(wasi_ext)] to the top of mio/src/lib.rs.