cpetig / resource-demo

A demo showing WASM component model resources in various environments

A demo showing WASM component model resources in various environments

Prerequisites

Rust target wasm32-wasi:

rustup target add wasm32-wasi

CMake

cpetig/wit-bindgen:

git clone https://github.com/cpetig/wit-bindgen.git
cd wit-bindgen
cargo install --path .

Working

	Guest	Host
C	✅ wit-bindgen	see below1
C++	🚧 cpetig/wit-bindgen	🚧 cpetig/wit-bindgen + WAMR
Rust	✅ wit-bindgen	✅ wasmtime 2
JavaScript	🚧 3	✅ jco 2
Go	☁️ 4	?
Python	🚧 5	🚧 5

Compiling and Running

cd guest-rust
cargo build --target wasm32-wasi --release

cd ../host-wamr
./generate.sh
mkdir build
cd build
cmake ..
make
./executor

Expected Output:

drop with value 34

C guest

Prerequisite: wasi-SDK

cd guest-c
./generate.sh
make
cd ..
ln -sf guest-c/guest-c.wasm guest.wasm 

Wasmtime host

You need a preview1 adapter matching the wasmtime version, see https://github.com/bytecodealliance/wasmtime/releases for the command adapter downloads.

But most likely you will need to check out the exact same wasmtime used for the host and build the adapter:

cd wasmtime/crates/wasi-preview1-component-adapter
cargo build -p wasi-preview1-component-adapter --target wasm32-unknown-unknown --release --features command --no-default-features
cp ../../target/wasm32-unknown-unknown/release/wasi_snapshot_preview1.wasm …/resource-demo/host-wasmtime

Jco host

Sorry, jco is currently broken until I figure out to compile typescript (shouldn't be that difficult to do).

Please use the adapter built from the wasmtime source (see above)

cargo install simple-http-server
./generate.sh
simple-http-server --cors --coop --coep --nocache -i html

Other environments

Host languages

• Rust:

  Wasmer bindgen only supports the old witx, not the newer wit format. You could write a host binding generator within wit-bindgen though.

• Python: https://pypi.org/project/componentize-py/ (?)

WASI preview2 adapter

The wasmtime host requires wasi_snapshot_preview1.wasm from (the dev branch) (WASI has recently migrated to resources)

JCO's preview2 browser shim still needs the older adapter

Guest languages

JavaScript: https://github.com/bytecodealliance/javy is potentially smaller than spidermonkey embedded by jco, you will need another tool to generate guest bindings for imported functions, IIRC. A path using C bindings with yet to be written JavaScript wrapping should be viable.

Footnotes

1. Currently I generate C++ host bindings for WAMR, C would be feasible. ↩

2. JCO and wasmtime currently need a different preview1 to preview2 adapter version ↩ ↩²

3. Jco likely needs the unfinished https://github.com/bytecodealliance/componentize-js/tree/resources for resource support in guests ↩

4. Go: WIT bindgen support is being worked on ↩

5. Python: https://pypi.org/project/componentize-py/ recently gained resource support ↩ ↩²