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 (see our index-compile.html demo on GitHub, and view it live also) compiles the loaded simple.wasm
byte code using the WebAssembly.compileStreaming()
method and then sends the resulting Module
instance to a worker using postMessage()
.
var worker = new Worker("wasm_worker.js");
WebAssembly.compileStreaming(fetch('simple.wasm'))
.then(mod =>
worker.postMessage(mod)
);
In the worker (see wasm_worker.js
) we define an import object for the module to use, then set 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.
var importObject = {
imports: {
imported_func: function(arg) {
console.log(arg);
}
}
};
onmessage = function(e) {
console.log('module received from main thread');
var mod = e.data;
WebAssembly.instantiate(mod, importObject).then(function(instance) {
instance.exports.exported_func();
});
};
Specifications
Specification |
---|
WebAssembly JavaScript Interface # modules |
Browser compatibility
BCD tables only load in the browser