node.js - Nodejs异步: concurency worker push the same task again in the queue

Question

我想知道在使用完 NodeJS 的异步模块后，将新任务无限期地再次推送到队列中的最佳方法是什么？

var q = async.queue(function (task, callback) {
    console.log('hello ' + task.name);
    doSomeFunction(task.name, function(cb){
        callback();
    });
}, 2);

q.drain = function() {
    console.log('all items have been processed');
}

// add some items to the queue
for (var i in list) {
    q.push({name: i}, function (err) {
       console.log('finished task');
       //***HERE I would like to push indefinitely this task in the queue again
    });
}

Answer 1

你必须执行递归函数。

for (var i in list) {
   //Put inside an anonymous function to keep the current value of i
   (function(item) {
     var a=function(item){
       q.push({name: item}, function (err) {
          console.log('finished task');
          //call the function again
          a(item)
       });
     }
     a(item)
   })(i);
}

此 cod 将无限期地添加队列中的所有任务，一个接一个(当任务完成时，会将相同的任务添加到队列中)。

顺便说一句...您没有在工作函数中调用回调

var q = async.queue(function (task, callback) {
   console.log('hello ' + task.name);
   //You have to call the callback
   //You have 2 options: 
   doSomeFunction(task.name,callback); //option 1 -> doSomeFunction - asynchronous function 
   //doSomeFunction(task.name);callback(); //option 2 doSomeFunction - synchronous function 
}, 2);