WebAssembly.Module
A WebAssembly.Module
object contains stateless WebAssembly code that has already been compiled by the browser — this can be efficiently shared with Workers, and instantiated multiple times.
Constructor
WebAssembly.Module()
-
Creates a new
Module
object.
Static properties
WebAssembly.Module.customSections()
-
Given a
Module
and string, returns a copy of the contents of all custom sections in the module with the given string name. WebAssembly.Module.exports()
-
Given a
Module
, returns an array containing descriptions of all the declared exports. WebAssembly.Module.imports()
-
Given a
Module
, returns an array containing descriptions of all the declared imports.
Examples
Sending a compiled module to a worker
The following example compiles the loaded simple.wasm
byte code using the WebAssembly.compileStreaming()
method and sends the resulting Module
instance to a worker using postMessage()
.
See the index-compile.html
source code or view it live.
js
const worker = new Worker("wasm_worker.js");
WebAssembly.compileStreaming(fetch("simple.wasm")).then((mod) =>
worker.postMessage(mod)
);
The worker function wasm_worker.js
defines an import object for the module to use. The function then sets up an event handler to receive the module from the main thread. When the module is received, we create an instance from it using the WebAssembly.instantiate()
method and invoke an exported function from inside it.
js
const importObject = {
imports: {
imported_func(arg) {
console.log(arg);
},
},
};
onmessage = (e) => {
console.log("module received from main thread");
const mod = e.data;
WebAssembly.instantiate(mod, importObject).then((instance) => {
instance.exports.exported_func();
});
};
Specifications
Specification |
---|
WebAssembly JavaScript Interface # modules |
Browser compatibility
BCD tables only load in the browser