Timeouts implementation for dgram sockets on nodejs

Question

I want to implement a timeout for dgram sockets in NodeJS. I looked around for a native udp solution like the socket.setTimeout in net library.

Here is what I am thinking:

const Dgram = require("dgram");

const udpSocket = Dgram.createSocket("udp4");

const promiseTimeout = (promise, ms=5000) => {

  // Create a promise that rejects in <ms> milliseconds
  const timeoutPromise = new Promise(resolve => {
    const timeout = setTimeout(() => {
      clearTimeout(timeout);
      resolve(false);
    }, ms);
  });

  // Returns a race between timeout and the passed in promise
  return Promise.race([
    promise,
    timeout
  ]);
};

const sendUdpMessage = (message, host, port) => {
  return new Promise(resolve => {
    udpSocket.send(message, 0, message.length, port, host);
    udpSocket.on("message", (incomingMessage, rinfo) => {
      console.log("I got message on udp", incomingMessage);
      resolve(true);
    });
  });
};

const test = async () => {
  const didUdpGotResponse = await promiseTimeout(sendUdpMessage("hello", "localhost", 5555));
  console.log(didUdpGotResponse);
}

test();

There are some issues with this implementation, for example I am binding a new on message listener, every time I send a new datagram. I welcome any suggestions for a timeout implementation

Answer 1

how about this

const dgram = require('dgram')
const client = dgram.createSocket('udp4')
let timer = null

client.on('error', (err) => {
    console.log(`client err：\n${ err.stack }`)
    client.close()
})

client.on('message', msg => {
    clearTimeout(timer)
    console.log('I got message on udp')
})

ping()

function isTimeout () {
    timer = setTimeout(() => {
        console.log('udp request timeout')
    }, 1000)
}

function ping () {
    client.send('hello', 8080, 'localhost')
    isTimeout()
}