WebAssembly.Module() constructor
A WebAssembly.Module()
constructor creates a new Module
object containing stateless WebAssembly code that has already been compiled by the
browser and can be efficiently shared with Workers, and instantiated multiple times.
The WebAssembly.Module()
constructor function can be called to
synchronously compile given WebAssembly binary code. However, the primary way to get a
Module
is through an asynchronous compilation function like
WebAssembly.compile()
.
Note: Webpages that have strict Content Security Policy (CSP) might block WebAssembly from compiling and executing modules. For more information on allowing WebAssembly compilation and execution, see the script-src CSP.
Syntax
Warning: Since compilation for large modules can be expensive,
developers should only use the Module()
constructor when synchronous
compilation is absolutely required; the asynchronous
WebAssembly.compileStreaming()
method should be used at all other times.
new WebAssembly.Module(bufferSource)
Parameters
bufferSource
-
A typed array or ArrayBuffer containing the binary code of the Wasm module you want to compile.
Exceptions
-
If the parameter is not of the correct type or structure, a
TypeError
is thrown. -
If compilation fails, the constructor rejects with a
WebAssembly.CompileError
. - Some browsers may throw a
RangeError
, as they prohibit compilation and instantiation of Wasm with large buffers on the UI thread.
Examples
Synchronously compiling a WebAssembly module
const importObject = {
my_namespace: {
imported_func(arg) {
console.log(arg);
},
},
};
function createWasmModule(bytes) {
return new WebAssembly.Module(bytes);
}
fetch("simple.wasm")
.then((response) => response.arrayBuffer())
.then((bytes) => {
const mod = createWasmModule(bytes);
WebAssembly.instantiate(mod, importObject).then((result) =>
result.exports.exported_func(),
);
});
Specifications
Specification |
---|
WebAssembly JavaScript Interface # dom-module-module |
Browser compatibility
BCD tables only load in the browser