WebAssembly.Memory object is a resizable ArrayBuffer or SharedArrayBuffer that holds the raw bytes of memory accessed by a WebAssembly Instance .

A memory created by JavaScript or in WebAssembly code will be accessible and mutable from both JavaScript and WebAssembly.

构造函数

WebAssembly.Memory()
创建新的 Memory 对象。

实例特性

Memory.prototype.buffer

An accessor property that returns the buffer contained in the memory.

实例方法

Memory.prototype.grow()

Increases the size of the memory instance by a specified number of WebAssembly pages (each one is 64KB in size).

范例

Creating a new Memory object

There are two ways to get a WebAssembly.Memory object. The first way is to construct it from JavaScript. The following example creates a new WebAssembly Memory instance with an initial size of 10 pages (640KiB), and a maximum size of 100 pages (6.4MiB). Its buffer property will return an ArrayBuffer .

var memory = new WebAssembly.Memory({initial:10, maximum:100});
					

The second way to get a WebAssembly.Memory object is to have it exported by a WebAssembly module.  The following example (see memory.html on GitHub, and view it live also ) fetches and instantiates the loaded memory.wasm byte code using the WebAssembly.instantiateStreaming() method, while importing the memory created in the line above. It then stores some values in that memory, then exports a function and uses it to sum some values.

WebAssembly.instantiateStreaming(fetch('memory.wasm'), { js: { mem: memory } })
.then(obj => {
  var i32 = new Uint32Array(memory.buffer);
  for (var i = 0; i < 10; i++) {
    i32[i] = i;
  }
  var sum = obj.instance.exports.accumulate(0, 10);
  console.log(sum);
});
					

Creating a shared memory

By default, WebAssembly memories are unshared. You can create a shared memory by passing shared: true in the constructor's initialization object:

let memory = new WebAssembly.Memory({initial:10, maximum:100, shared: true});
					

This memory's buffer property will return a SharedArrayBuffer .

规范

规范
WebAssembly JavaScript 接口
The definition of 'Memory' 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
Memory 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
Memory() 构造函数 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
buffer 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
grow 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

元数据

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