在NodeJS中安排异步功能 [英] Schedule an async function in NodeJS

问题描述

我想安排一个异步(异步/等待ruturn类型)的函数每两分钟运行一次.

I want to schedule a function which is asynchronous (async/await ruturn type) to run for every two minutes.

我尝试使用通用的setInterval节点模块，例如 node-schedule，cron，node-cron，async-poll ，但是无法实现对异步函数调用的轮询.

I tried with generic setInterval, node modules like node-schedule , cron, node-cron, async-poll but unable to achieve polling for a async function call.

这是我在代码中尝试过的:

This is what I tried in code:

cron.schedule("*/2 * * * *", await this.servicesManager.startPoll() => {
               console.log('running on every two minutes');
}); // this is not working breaks after first run

const job = schedule.scheduleJob(" star/1 * * * *", async function() {
   try {
         return await this.ServicesManager.startPoll(); // this function startPoll is undefined when using this 
       } catch (e) {
         console.log(e);
   }
   console.log('Run on every minute');
});

const event = schedule.scheduleJob("*/2 * * * *", this.ServicesManager.startPoll()); //using node-schedule , breaks after first time
cron.schedule("*/2 * * * *", await this.ServicesManager.startPoll()); // using cron same result as using node-schedule
return await this.ServicesManager.startPoll(); // without polling works

推荐答案

尝试类似的方法

// version 1
cron.schedule("*/2 * * * *", this.servicesManager.startPoll);

// version 2 => if servicesManager needs its `this` reference
cron.schedule("*/2 * * * *", async () => this.servicesManager.startPoll());

//version 3 ==> using node-schedule
schedule.scheduleJob("*/1 * * * *", async () => this.ServicesManager.startPoll());

我不知道您的servicesManager，您可能需要使用版本2"从上面开始工作.

I don't know about your servicesManager, you might have to use "version 2" from above to get it to work.

计划库需要一个函数来执行，但是在上面的示例中，它们得到了已解决的Promise.

The schedule libraries need a function to execute, but instead they get a resolved Promise in the examples above.

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