feat: copied from github.com/pmalmgren/wasi-data-sharing

examples/wasi/main.rs

@@ -0,0 +1,57 @@
+use anyhow::Result;
+use wasi_common::pipe::{ReadPipe, WritePipe};
+use wasmtime::*;
+use wasmtime_wasi::sync::WasiCtxBuilder;
+use wire::Input;
+
+use crate::wire::Output;
+
+mod wire;
+
+fn main() -> Result<()> {
+    // Define the WASI functions globally on the `Config`.
+    let engine = Engine::default();
+    let mut linker = Linker::new(&engine);
+    wasmtime_wasi::add_to_linker(&mut linker, |s| s)?;
+
+    let input = Input {
+        name: "Rust".into(),
+        num: 10,
+    };
+    let serialized_input = serde_json::to_string(&input)?;
+
+    let stdin = ReadPipe::from(serialized_input);
+    let stdout = WritePipe::new_in_memory();
+
+    let wasi = WasiCtxBuilder::new()
+        .stdin(Box::new(stdin.clone()))
+        .stdout(Box::new(stdout.clone()))
+        .build();
+
+    let module = Module::from_file(&engine, "target/wasm32-wasi/debug/wasi-demo.wasm")?;
+
+    let mut store = Store::new(&engine, wasi);
+
+    linker
+        .module(&mut store, "", &module)
+        .expect("linking the function");
+    linker
+        .get_default(&mut store, "")
+        .expect("should get the wasi runtime")
+        .typed::<(), (), _>(&store)
+        .expect("should type the function")
+        .call(&mut store, ())
+        .expect("should call the function");
+
+    drop(store);
+
+    let contents: Vec<u8> = stdout
+        .try_into_inner()
+        .map_err(|_err| anyhow::Error::msg("sole remaining reference"))?
+        .into_inner();
+    let output: Output = serde_json::from_slice(&contents)?;
+
+    println!("output: {:?}", output);
+
+    Ok(())
+}