在此页

• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

WebAssembly.instantiate() function allows you to compile and instantiate WebAssembly code. This function has two overloads:

• The primary overload takes the WebAssembly binary code, in the form of a typed array or ArrayBuffer , and performs both compilation and instantiation in one step. The returned Promise resolves to both a compiled WebAssembly.Module and its first WebAssembly.Instance .
• The secondary overload takes an already-compiled WebAssembly.Module and returns a Promise that resolves to an Instance of that Module . This overload is useful if the Module has already been compiled.

Important : This method is not the most efficient way of fetching and instantiating wasm modules. If at all possible, you should use the newer WebAssembly.instantiateStreaming() method instead, which fetches, compiles, and instantiates a module all in one step, directly from the raw bytecode, so doesn't require conversion to an ArrayBuffer .

句法

Primary overload — taking wasm binary code

Promise<ResultObject> WebAssembly.instantiate(bufferSource, importObject);
					

参数

bufferSource

A typed array or ArrayBuffer containing the binary code of the .wasm module you want to compile.

importObject 可选

An object containing the values to be imported into the newly-created Instance , such as functions or WebAssembly.Memory objects. There must be one matching property for each declared import of the compiled module or else a WebAssembly.LinkError is thrown.

返回值

A Promise 解析为 ResultObject which contains two fields:

• module : A WebAssembly.Module object representing the compiled WebAssembly module. This Module can be instantiated again, shared via postMessage() or cached in IndexedDB .
• instance : A WebAssembly.Instance object that contains all the Exported WebAssembly functions .

异常

• If either of the parameters are not of the correct type or structure, a TypeError is thrown.
• If the operation fails, the promise rejects with a WebAssembly.CompileError , WebAssembly.LinkError ，或 WebAssembly.RuntimeError , depending on the cause of the failure.

Secondary overload — taking a module object instance

Promise<WebAssembly.Instance> WebAssembly.instantiate(module, importObject);
					

参数

module

WebAssembly.Module object to be instantiated.

importObject 可选

An object containing the values to be imported into the newly-created Instance , such as functions or WebAssembly.Memory objects. There must be one matching property for each declared import of module or else a WebAssembly.LinkError is thrown.

返回值

A Promise that resolves to an WebAssembly.Instance 对象。

异常

• If either of the parameters are not of the correct type or structure, a TypeError is thrown.
• If the operation fails, the promise rejects with a WebAssembly.CompileError , WebAssembly.LinkError ，或 WebAssembly.RuntimeError , depending on the cause of the failure.

范例

注意 : You'll probably want to use WebAssembly.instantiateStreaming() in most cases, as it is more efficient than instantiate() .

First overload example

After fetching some WebAssembly bytecode using fetch, we compile and instantiate the module using the WebAssembly.instantiate() function, importing a JavaScript function into the WebAssembly Module in the process. We then call an Exported WebAssembly function that is exported by the Instance .

var importObject = {
  imports: {
    imported_func: function(arg) {
      console.log(arg);
    }
  }
};
fetch('simple.wasm').then(response =>
  response.arrayBuffer()
).then(bytes =>
  WebAssembly.instantiate(bytes, importObject)
).then(result =>
  result.instance.exports.exported_func()
);
						

注意 : You can also find this example at index.html on GitHub ( view it live also ).

Second overload example

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 it to a worker 使用 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();
  });
};
						

规范

规范
WebAssembly JavaScript 接口 The definition of 'instantiate()' in that specification.

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
instantiate	Chrome 57	Edge 16	Firefox 52 52 Disabled in the Firefox 52 Extended Support Release (ESR).	IE No	Opera 44	Safari 11	WebView Android 57	Chrome Android 57	Firefox Android 52 52 Disabled in the Firefox 52 Extended Support Release (ESR).	Opera Android 43	Safari iOS 11	Samsung Internet Android 7.0	nodejs 8.0.0

图例

完整支持

完整支持

不支持

不支持

见实现注意事项。

另请参阅

• WebAssembly 概述页面
• WebAssembly 概念
• 使用 WebAssembly JavaScript API

元数据

• 最后修改： Feb 13, 2020

相关话题

1. 标准内置对象
2. WebAssembly
3. 方法
   1. WebAssembly.compile()
   2. WebAssembly.compileStreaming()
   3. WebAssembly.instantiate()
   4. WebAssembly.instantiateStreaming()
   5. WebAssembly.validate()
4. 相关页面：
5. WebAssembly.Module
6. WebAssembly.Global
7. WebAssembly.Instance
8. WebAssembly.Memory
9. WebAssembly.Table
10. WebAssembly.CompileError
11. WebAssembly.LinkError
12. WebAssembly.RuntimeError
13. 继承：
14. Object
15. 特性
    1. Object.prototype.__proto__
    2. Object.prototype.constructor
16. 方法
    1. Object.prototype.__defineGetter__()
    2. Object.prototype.__defineSetter__()
    3. Object.prototype.__lookupGetter__()
    4. Object.prototype.__lookupSetter__()
    5. Object.prototype.hasOwnProperty()
    6. Object.prototype.isPrototypeOf()
    7. Object.prototype.propertyIsEnumerable()
    8. Object.prototype.toLocaleString()
    9. Object.prototype.toSource()
    10. Object.prototype.toString()
    11. Object.prototype.valueOf()
    12. Object.setPrototypeOf()