Files
wazero/imports/go
Takeshi Yoneda b63d4e6dcd Deletes namespace API (#1018)
Formerly, we introduced `wazero.Namespace` to help avoid module name or import conflicts while still sharing the runtime's compilation cache. Now that we've introduced `CompilationCache` `wazero.Namespace` is no longer necessary. By removing it, we reduce the conceptual load on end users as well internal complexity. Since most users don't use namespace, the change isn't very impactful.

Users who are only trying to avoid module name conflict can generate a name like below instead of using multiple runtimes:

```go
moduleName := fmt.Sprintf("%d", atomic.AddUint64(&m.instanceCounter, 1))
module, err := runtime.InstantiateModule(ctx, compiled, config.WithName(moduleName))
```

For `HostModuleBuilder` users, we no longer take `Namespace` as the last parameter of `Instantiate` method: 

```diff
 	// log to the console.
 	_, err := r.NewHostModuleBuilder("env").
 		NewFunctionBuilder().WithFunc(logString).Export("log").
-		Instantiate(ctx, r)
+		Instantiate(ctx)
 	if err != nil {
 		log.Panicln(err)
 	}
```


The following is an example diff a use of namespace can use to keep compilation cache while also ensuring their modules don't conflict:

```diff

 func useMultipleRuntimes(ctx context.Context, cache) {
-	r := wazero.NewRuntime(ctx)
+	cache := wazero.NewCompilationCache()
 
 	for i := 0; i < N; i++ {
-		// Create a new namespace to instantiate modules into.
-		ns := r.NewNamespace(ctx) // Note: this is closed when the Runtime is
+		r := wazero.NewRuntimeWithConfig(ctx, wazero.NewRuntimeConfig().WithCompilationCache(cache))
 
 		// Instantiate a new "env" module which exports a stateful function.
 		_, err := r.NewHostModuleBuilder("env").
```

Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>
2023-01-10 14:11:46 +09:00
..
2023-01-10 09:32:42 +09:00
2023-01-10 14:11:46 +09:00

Overview

When GOOS=js and GOARCH=wasm, Go's compiler targets WebAssembly Binary format (%.wasm).

Wazero's "github.com/tetratelabs/wazero/imports/go" package allows you to run a %.wasm file compiled by Go. This is similar to what is implemented in wasm_exec.js. See https://wazero.io/languages/go/ for more.

Example

wazero includes an example that makes HTTP client requests.

Experimental

Go defines js "EXPERIMENTAL... exempt from the Go compatibility promise." Accordingly, wazero cannot guarantee this will work from release to release, or that usage will be relatively free of bugs. Due to this and the relatively high implementation overhead, most will choose TinyGo instead.