[Solved/Workaround] Custom data for Network Discovery component

Unity Engine
1

I’m trying to write a custom network discovery component to supply it with custom data (based on HLAPI source).
So this question a bit LLAPI.
Is there a way to change buffer array data after calling NetworkTransport.StartBroadcastDiscovery?

Seems like there’s only get methods on it.

2

Anyone? This could be very usefull, e.g. broadcasting current player count etc.

Maybe @aabramychev can give a little hint?

I really don’t want to implement a custom server for the functionality that may already exist.

3

Okay, since nobody offered anything, I’ve came up with a workaround. Restarting BroadcastDiscovery on my own in a coroutine at certain intervals and refreshing the buffer. Not the prettiest solution, but it works.

Here’s pseudo-code for those who may encounter same problem in the future:

        // StartAsServer replacement
        /// <summary>
        /// Perform broadcasts over network
        /// </summary>
        public bool StartAsServer() {
          ...

            _hostId = NetworkTransport.AddHost(_defaultTopology, 0);
           ...

            byte err;

           // Fill buffer here!
            _msgOutBuffer = CompileBuffer(_matchMetadata);

            if (!NetworkTransport.StartBroadcastDiscovery(_hostId,
                                                          BroadcastPort,
                                                          BroadcastKey,
                                                          BroadcastVersion,
                                                          BroadcastSubVersion,
                                                          _msgOutBuffer,
                                                          _msgOutBuffer.Length,
                                                          MBroadcastInterval,
                                                          out err)) {
                return false;
            }

            Running = true;
            IsServer = true;

            _refreshBufferCoroutine = StartCoroutine(UpdateBroadcastData());

           ....

            return true;
        }

        /// <summary>
        /// Workaround coroutine to update the buffer of broadcast server
        /// </summary>
        /// <returns></returns>
        private IEnumerator UpdateBroadcastData() {
            yield return _refreshDelay;
        
            while (Running) {
                NetworkTransport.StopBroadcastDiscovery();
                NetworkTransport.RemoveHost(_hostId);

                // We need to wait until remove operation finishes, otherwise NetworkTransport will throw that
                // NetworkDiscovery is still running
                while (NetworkTransport.IsBroadcastDiscoveryRunning()) {
                    yield return _recheckDelay;
                }

                if (!Running) {
                    yield break;
                }

                _hostId = NetworkTransport.AddHost(_defaultTopology, 0);
                byte err;
             
                // Update buffer here
                _msgOutBuffer = CompileBuffer(_matchMetadata);

                if (!NetworkTransport.StartBroadcastDiscovery(_hostId,
                                                              BroadcastPort,
                                                              BroadcastKey,
                                                              BroadcastVersion,
                                                              BroadcastSubVersion,
                                                              _msgOutBuffer,
                                                              _msgOutBuffer.Length,
                                                              MBroadcastInterval,
                                                              out err)) {
                    yield break;
                }

                yield return _refreshDelay;
            }
        }

_refreshDelay is WaitForSeconds(5) and _recheckDelay is WaitForSeconds(0.1)

Everything else is from NetworkDiscovery source of HLAPI, though it’s refactored for our code style. Full source of that you can always find on Unity’s BitBucket.

4

Hm, not sure, bit if i remember if you stop discovery, change buffer and start it again it will change

5

That’s exactly what I’m doing right now.

1 Like