据我所知，web worker需要写在一个单独的JavaScript文件中，并像这样调用:
new Worker('longrunning.js')
我正在使用闭包编译器来合并和缩小我所有的JavaScript源代码，我不希望将我的worker放在单独的文件中进行分发。有什么办法可以做到吗?
new Worker(function() {
//Long-running work here
});
既然一级函数对JavaScript如此重要，为什么标准的后台工作方式必须从web服务器加载整个其他JavaScript文件呢?
当前回答
这是一个有点离题的答案，但是……您可能不需要使用网络工作者来处理浏览器上的长时间工作。
让我们假设你想要运行几次繁重的计算(就像你对数组做的那样):
const heavyFct = () => {let i = 0; while(i<1e8) {++i}}
for (let i = 0; i < 100; ++i) {
heavyFct();
}
这将冻结您的浏览器。
为了避免这种情况，我们可以这样依赖setTimeout:
const desync = (i = 0) => {
if (i >= 100) {return}
heavyFct();
setTimeout(() => desync(i + 1), 0);
}
desync();
现在，您可以在不冻结计算机的情况下运行繁重的计算
其他回答
使用我的小插件https://github.com/zevero/worker-create
var worker_url = Worker.createURL(function(e){
self.postMessage('Example post from Worker'); //your code here
});
var worker = new Worker(worker_url);
我喜欢ifbamoq给出的答案，但由于堆栈溢出的积分政策，我无法评论。因此，我将给出一个示例，展示一些正在进行的密集工作——以及它如何不锁定主线程。
如果你像我一样双击html文件，把它们当成小程序，就不会遇到空原点的CORS问题。: -)
<!DOCTYPE html> <html> <head> <title>Worker example: One-core computation</title> </head> <body> <p>The highest prime number discovered so far is: <div id="result"></div></p> </body> <script> // let worker = new Worker('WebWorker.js'); // lets skip this to avoid null origin issues let WorkerFn = (event) => { let isPrime = false; for (let n = 2; n <= 1_000_000; n++) { isPrime = true; for(let i = 2; i <= Math.sqrt(n); i++) if (n % i == 0) isPrime = false; // If you can get thru all this shit and survive, ur prime! if (isPrime) postMessage(n); } } let worker = new Worker(window.URL.createObjectURL(new Blob(["(" + WorkerFn.toString() + ")()"], {type: "text/javascript"}))); worker.onmessage = (event) => { result.innerHTML = event.data; } </script> </html>
https://developer.mozilla.org/es/docs/Web/Guide/Performance/Using_web_workers
// Syntax: asyncEval(code[, listener])
var asyncEval = (function () {
var aListeners = [], oParser = new Worker("data:text/javascript;charset=US-ASCII,onmessage%20%3D%20function%20%28oEvent%29%20%7B%0A%09postMessage%28%7B%0A%09%09%22id%22%3A%20oEvent.data.id%2C%0A%09%09%22evaluated%22%3A%20eval%28oEvent.data.code%29%0A%09%7D%29%3B%0A%7D");
oParser.onmessage = function (oEvent) {
if (aListeners[oEvent.data.id]) { aListeners[oEvent.data.id](oEvent.data.evaluated); }
delete aListeners[oEvent.data.id];
};
return function (sCode, fListener) {
aListeners.push(fListener || null);
oParser.postMessage({
"id": aListeners.length - 1,
"code": sCode
});
};
})();
这只是上面的一个补充-我在jsFiddle中有一个很好的模板用于测试web worker。而不是Blob，它使用jsFiddles ?js api:
function workerFN() {
self.onmessage = function(e) {
switch(e.data.name) {
case "" :
break;
default:
console.error("Unknown message:", e.data.name);
}
}
}
// This is a trick to generate real worker script that is loaded from server
var url = "/echo/js/?js="+encodeURIComponent("("+workerFN.toString()+")()");
var worker = new Worker(url);
worker.addEventListener("message", function(e) {
switch(e.data.name) {
case "" :
break;
default:
console.error("Unknown message:", e.data.name);
}
})
有普通的web worker模板和共享worker模板。
我的看法是:
function BuildWorker(fn){
var str = fn.toString().match(/^[^{]+{([\s\S]+)}\s*$/m)[1];
return new Worker(window.URL.createObjectURL(
new Blob([str],{type:'text/javascript'})));
}
function createAsyncWorker(fn){
// asyncworker=createAsyncWorker(function(){
// importScripts('my_otherscript.js');
// self.onmessage = function([arg1,arg2]) {
// self.postMessage('msg from worker');
// };
// })
// await asyncworker.postMessage('arg1','value')
// await asyncworker.postMessage('arg1','value')
// asyncworker.worker.terminate()
var worker = BuildWorker(fn);
function postMessage(...message){
let external={}, promise= new Promise((resolve,reject)=>{external.resolve=resolve;external.reject=reject;})
worker.onmessage = function(message){ external.resolve(message.data)};
worker.postMessage(message); // Start the worker.
return promise;
}
return {worker,postMessage};
}
使用的例子:
autoarima = createAsyncWorker(function(){
importScripts("https://127.0.0.1:11000/arima.js")
self.onmessage=(message)=>{
let [action,arg1,arg2]=message.data
if(action=='load')
{
ARIMAPromise.then(ARIMA1 => {
ARIMA=ARIMA1
autoarima = new ARIMA({ auto: true });
// const ts = Array(10).fill(0).map((_, i) => i + Math.random() / 5)
// const arima = new ARIMA({ p: 2, d: 1, q: 2, P: 0, D: 0, Q: 0, S: 0, verbose: false }).train(ts)
// const [pred, errors] = arima.predict(10)
postMessage('ok')
});
}
if(action=='fit')
{
autoarima.fit(arg1)
postMessage('ok')
}
if(action=='predict')
{
postMessage(autoarima.predict(arg1,arg2))
}
};
})
autoarima.terminate=function(){ this.worker.terminate(); }
autoarima.load=async function(...args){return await this.postMessage('load',...args)}
autoarima.fit=async function(...args){return await this.postMessage('fit',...args)}
autoarima.predict=async function(...args){return await this.postMessage('predict',...args)}
await autoarima.load()
await autoarima.fit(b_values)
await autoarima.predict(1)
