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.
WebAssembly.Memory()
Memory
对象。
Memory.prototype.buffer
An accessor property that returns the buffer contained in the memory.
Memory.prototype.grow()
Increases the size of the memory instance by a specified number of WebAssembly pages (each one is 64KB in size).
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);
});
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 |
|---|
|
WebAssembly JavaScript 接口
The definition of 'Memory' in that specification. |
| Desktop | Mobile | Server | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Memory
|
Chrome 57 | Edge 16 |
Firefox
52
|
IE No | Opera 44 | Safari 11 | WebView Android 57 | Chrome Android 57 |
Firefox Android
52
|
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
|
IE No | Opera 44 | Safari 11 | WebView Android 57 | Chrome Android 57 |
Firefox Android
52
|
Opera Android 43 | Safari iOS 11 | Samsung Internet Android 7.0 | nodejs 8.0.0 |
buffer
|
Chrome 57 | Edge 16 |
Firefox
52
|
IE No | Opera 44 | Safari 11 | WebView Android 57 | Chrome Android 57 |
Firefox Android
52
|
Opera Android 43 | Safari iOS 11 | Samsung Internet Android 7.0 | nodejs 8.0.0 |
grow
|
Chrome 57 | Edge 16 |
Firefox
52
|
IE No | Opera 44 | Safari 11 | WebView Android 57 | Chrome Android 57 |
Firefox Android
52
|
Opera Android 43 | Safari iOS 11 | Samsung Internet Android 7.0 | nodejs 8.0.0 |
完整支持
不支持
见实现注意事项。
WebAssembly
WebAssembly.Module
WebAssembly.Global
WebAssembly.Instance
WebAssembly.Memory
WebAssembly.Table
WebAssembly.CompileError
WebAssembly.LinkError
WebAssembly.RuntimeError
Object
Object.prototype.__defineGetter__()
Object.prototype.__defineSetter__()
Object.prototype.__lookupGetter__()
Object.prototype.__lookupSetter__()
Object.prototype.hasOwnProperty()
Object.prototype.isPrototypeOf()
Object.prototype.propertyIsEnumerable()
Object.prototype.toLocaleString()
Object.prototype.toSource()
Object.prototype.toString()
Object.prototype.valueOf()
Object.setPrototypeOf()