Hello!

I have a question about the internal TCP connection. As I see, there are two ways to handle an MQTT packet: asynchronous (default) and sequential (using handleMessage function).

I'm using this client library with the EMQX broker.

In the first case, when I don't override the handleMessage function and subscribe to incoming messages, everything works fine.
However, this doesn't work for me as I need to handle messages one at a time.

So, I overridden the handleMessage function and put all the logic there. But now, when I generate more than 1k req/s, I get a TCP socket overload warning from the broker and after a while, I get a TCP timeout error, and my client just closes.

As far as I know this repository, there is no difference between the TCP connection implementation in these two cases (in both cases, one connection is kept until there are no parsed mqtt packets left in the internal queue). Sample from connect() function in src/lib/client.ts

const work = () => {
  this.log('work :: getting next packet in queue');
  const packet = packets.shift();

  if (packet) {
    this.log('work :: packet pulled from queue');
    handlePacket(this, packet, nextTickWork);
  } else {
    this.log('work :: no packets in queue');
    const done = completeParse;
    completeParse = null;
    this.log('work :: done flag is %s', !!done);
    if (done) done();
  }
};

const nextTickWork = () => {
  if (packets.length) {
    nextTick(work);
  } else {
    const done = completeParse;
    completeParse = null;
    done();
  }
};

writable._write = (buf, enc, done) => {
  completeParse = done;
  this.log('writable stream :: parsing buffer');
  parser.parse(buf);
  work();
};

Is this the correct understanding, or am I missing something? Thank you in advance for your help.