JS:执行事件在另一个时间上重叠 [英] JS: Executing events overlapping in time afteranother

问题描述

我以正确的顺序即时接收事件，这些事件要依次处理(以及即时-因此不要先存储"事件).

I receive events on-the-fly in the correct order in which I want to process them after another (as well on-the-fly - so don't "store" them first).

下面的示例无法正常工作，因为函数 someEventOccured()可以在非常短的时间内被多次调用.因此，handleEvent的执行将在时间上重叠(我不希望如此).当我在 handleEvent()中写入文件时，我不能同时执行该功能，而需要保持顺序...

The following example is not going to work as the function someEventOccured() could be called multiple times in a very close timespan. Thus, the execution of handleEvent would overlap in time (which I don't want). As I am writing to a file in handleEvent() I cannot have simultaneously execute the function and need to maintain the order...

async someEventOccured(data:string){
   await handleEvent(data);
}

我已经尝试过使用.then()并存储promise，但是我不知道如何等待上一个.then()完成...

I have already tried using .then() and storing the promise, however I have no idea how to wait for the previous .then() to finish...

非常感谢您的帮助< 3

Your help is very appreciated <3

推荐答案

一般方法是让一个共享的诺言排队:

The general approach is to have a shared promise to queue onto:

let queue = Promise.resolve();
function someEventOccured(data:string) {
  queue = queue.then(() => {
    return handleEvent(data);
  }).catch(err => {
    // ensure `queue` is never rejected or it'll stop processing events
    // …
  });
}

当然，这确实将 data 事件隐式存储在promise链的闭包中.

Of course, this does implicitly store the data events in the closures on the promise chain.

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