You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
69 lines
2.4 KiB
69 lines
2.4 KiB
//! Small example of how to serialize compiled wasm module to the disk,
|
|
//! and then instantiate it from the compilation artifacts.
|
|
|
|
// You can execute this example with `cargo run --example serialize`
|
|
|
|
use anyhow::Result;
|
|
use wasmtime::*;
|
|
|
|
fn serialize() -> Result<Vec<u8>> {
|
|
// Configure the initial compilation environment, creating the global
|
|
// `Store` structure. Note that you can also tweak configuration settings
|
|
// with a `Config` and an `Engine` if desired.
|
|
println!("Initializing...");
|
|
let engine = Engine::default();
|
|
|
|
// Compile the wasm binary into an in-memory instance of a `Module`.
|
|
println!("Compiling module...");
|
|
let module = Module::from_file(&engine, "examples/hello.wat")?;
|
|
let serialized = module.serialize()?;
|
|
|
|
println!("Serialized.");
|
|
Ok(serialized)
|
|
}
|
|
|
|
fn deserialize(buffer: &[u8]) -> Result<()> {
|
|
// Configure the initial compilation environment, creating the global
|
|
// `Store` structure. Note that you can also tweak configuration settings
|
|
// with a `Config` and an `Engine` if desired.
|
|
println!("Initializing...");
|
|
let store = Store::default();
|
|
|
|
// Compile the wasm binary into an in-memory instance of a `Module`.
|
|
println!("Deserialize module...");
|
|
let module = Module::deserialize(store.engine(), buffer)?;
|
|
|
|
// Here we handle the imports of the module, which in this case is our
|
|
// `HelloCallback` type and its associated implementation of `Callback.
|
|
println!("Creating callback...");
|
|
let hello_func = Func::wrap(&store, || {
|
|
println!("Calling back...");
|
|
println!("> Hello World!");
|
|
});
|
|
|
|
// Once we've got that all set up we can then move to the instantiation
|
|
// phase, pairing together a compiled module as well as a set of imports.
|
|
// Note that this is where the wasm `start` function, if any, would run.
|
|
println!("Instantiating module...");
|
|
let imports = [hello_func.into()];
|
|
let instance = Instance::new(&store, &module, &imports)?;
|
|
|
|
// Next we poke around a bit to extract the `run` function from the module.
|
|
println!("Extracting export...");
|
|
let run = instance
|
|
.get_func("run")
|
|
.ok_or(anyhow::format_err!("failed to find `run` function export"))?
|
|
.get0::<()>()?;
|
|
|
|
// And last but not least we can call it!
|
|
println!("Calling export...");
|
|
run()?;
|
|
|
|
println!("Done.");
|
|
Ok(())
|
|
}
|
|
|
|
fn main() -> Result<()> {
|
|
let file = serialize()?;
|
|
deserialize(&file)
|
|
}
|
|
|