[Fun Exercise]Make an MQTT broker in Node-RED

General
61

I decided that dealing with an unexpected unsubscribe request was probably something that my broker should be able to handle

So I'm just leaving the Snap! end alone as all other brokers I've used it with can handle unsubs where no sub exists :slight_smile:

62

In other news - I'm well chuffed that despite my NR instance failing overnight - when I restarted it - an existing MQTT session between it and my local running Snap! project just carried on working :slight_smile:
It may become a real Aedes rival for a pop-up broker :slight_smile:

63

I can now deal with messages > 127 chars having implemented (Found some JS code to do it and re-did in blockly) a function to cope with the unique MQTT variable length value

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FYI This was my transcoding of a JS snippet found on github

function decode(bytes = []) {
  let multiplier = 1;
  let value = 0;
  let currentIndex = 0;
  let encodedByte;
  do {
    encodedByte = bytes[currentIndex];
    value += (encodedByte & 127) * multiplier;
    multiplier *= 128;
    if (multiplier > 128 * 128 * 128) {
      throw new Error('Malformed Remaining Length');
    }
    currentIndex++;
  } while ((bytes[currentIndex] !== undefined && (encodedByte & 128 !== 0)))

  return value;
}