Javascript - 如何使 ping 结果始终按照数组变量的原点顺序

Question

我想根据数组变量的起源始终按顺序获得 ping 结果。

代码来源于here

这是代码:

var ping = require ('net-ping');

var targets = ['8.8.8.8','8.8.4.4'];

var session = ping.createSession();

for (var i = 0; i < targets.length; i++) {
    session.pingHost (targets[i], function (error, target, sent, rcvd) {
        var ms = rcvd - sent;
        if (error) {
            if (error instanceof ping.RequestTimedOutError) {
                target;
            } else {
                error.toString ();
            }                      
        } else {
            var result = target + ": " + ms + " ms";
            console.log(result);
        }             
    });
}

如果我运行代码三次，结果是:

// first
8.8.8.8: 6 ms
8.8.4.4: 8 ms

// second
8.8.4.4: 7 ms   <- // the list of ip address is not sequential
8.8.8.8: 10 ms  <- // not like the first and third result

// third
8.8.8.8: 5 ms
8.8.4.4: 9 ms

我认为 ping 结果是以 ms(毫秒)为单位的最小值将首先显示，但是如何使结果始终像数组变量的起源一样连续显示 var Targets = ['8.8.8.8','8.8. 4.4']？

也许我必须将结果放入数组并使其按顺序排列，但我不知道该怎么做。

有人可以帮助我吗？

Answer 1

Promise 让这变得非常简单

Promise.all(targets.map(tgt => 
    new Promise(resolve => 
        session.pingHost(tgt, (error, target, sent, rcvd) =>
            resolve({error, target, sent, rcvd})
            // resolves to an object containing all the arguments in the callback
            // note: always resolve, even for error - so promise.all can work for you
        )
    )
)).then(results => {
    // results array, same order as targets array
    // process all the results here
    results.forEach(({error, target, sent, rcvd}) => {
        // here are all the original arguments in the callback for pingHost resolved above
        // all the "logic" you perform in the pingHost callback in your code can be done here, and this is after all results are in
    }
});

如果你愿意，我可以发布不使用 Promises 的代码，但由于你使用的是 Nodejs，所以请使用 Promises :p