将函数发布到webworker

问题描述 投票:0回答:2

如何将函数(的副本)从我的主线程发送到我的工作线程?

每当我尝试:

worker.postMessage({data, func: (data) => data)
时,Firefox 都会给我一条错误消息:DataCloneError:无法克隆该对象。

对于 Chrome,消息有所不同,但错误仍然发生: Uncaught DOMException: Failed toexecute 'postMessage' on 'Worker': An object Could not be cloned.

javascript web-worker
2个回答
1
投票

是的,这是可能的,我做到了,而且比这更好的是,我可以创建没有 js 文件的 Web Worker,只需使用 javascript 代码生成的 Blob 文件。

setInterval(()=>{console.log("non bloked " + Math.random())}, 900)

console.log("starting blocking code in Worker")
console.time("blocked")

genericWorker(window, ["blockCpu", function (block){    
    block(10000) //This blockCpu function is defined below
    return `\n\nbla ${123123*2312} bla \n` //This is catched in the resolved promise

}]).then(function (result){
    console.timeEnd("blocked")
    console.log("End of blocking code", result)
})
.catch(function(error) { console.log(error) })


/*  A Web Worker that does not use a File, it create that from a Blob
    @cb_context, The context where the callback functions arguments are, ex: window
    @cb, ["fn_name1", "fn_name2", function (fn1, fn2) {}]
        The callback will be executed, and you can pass other functions to that cb
*/
function genericWorker(cb_context, cb) {
    return new Promise(function (resolve, reject) {

        if (!cb || !Array.isArray(cb))
            return reject("Invalid data")

        var callback = cb.pop()
        var functions = cb

        if (typeof callback != "function" || functions.some((fn)=>{return typeof cb_context[fn] != "function"}))
            return reject(`The callback or some of the parameters: (${functions.toString()}) are not functions`)

        if (functions.length>0 && !cb_context)
            return reject("context is undefined")

        callback = fn_string(callback) //Callback to be executed
        functions = functions.map((fn_name)=> { return fn_string( cb_context[fn_name] ) })

        var worker_file = window.URL.createObjectURL( new Blob(["self.addEventListener('message', function(e) { var bb = {}; var args = []; for (fn of e.data.functions) { bb[fn.name] = new Function(fn.args, fn.body); args.push(fn.name)}; var callback = new Function( e.data.callback.args, e.data.callback.body); args = args.map(function(fn_name) { return bb[fn_name] });  var result = callback.apply(null, args) ;self.postMessage( result );}, false)"]) )
        var worker = new Worker(worker_file)

        worker.postMessage({ callback: callback, functions: functions })

        worker.addEventListener('error', function(error){ return reject(error.message) })

        worker.addEventListener('message', function(e) {
            resolve(e.data), worker.terminate()
        }, false)

        //From function to string, with its name, arguments and its body
        function fn_string (fn) {
            var name = fn.name, fn = fn.toString()

            return { name: name, 
                args: fn.substring(fn.indexOf("(") + 1, fn.indexOf(")")),
                body: fn.substring(fn.indexOf("{") + 1, fn.lastIndexOf("}"))
            }
        }
    })
}

//random blocking function
function blockCpu(ms) {
    var now = new Date().getTime();
    var result = 0
    while(true) {
        result += Math.random() * Math.random();
        if (new Date().getTime() > now +ms)
            return;
    }   
}


0
投票

尚未对此进行测试,但从规范看来,只有可以发送给 Worker 的对象才是“可转移”对象: https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Transferable_objects

我找到了一些例子,第一个例子中的过程没有详细说明,但我猜他使用了一种类型或URL编码,对于一个对象,它可以像第二个例子一样转换为JSON。

如何将函数传递给 JavaScript Web Worker

将对象传递给网络工作者

我也必须在几天内完成此操作,我可以随时更新我所拥有的将要测试的内容..

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