chore: protected network manager (#2975)

* chore: make UnityTransport.NetworkManager protected

* use m_NetworkManager

* remove comments

* copy/paste

Author: DSchroer

com.unity.netcode.gameobjects/Runtime/Transports/UTP/UnityTransport.cs

@@ -450,7 +450,10 @@ private struct PacketLossCache
 
         private RelayServerData m_RelayServerData;
 
-        internal NetworkManager NetworkManager;
+        /// <summary>
+        /// NetworkManager associated to this transport instance
+        /// </summary>
+        protected NetworkManager m_NetworkManager;
 
         private IRealTimeProvider m_RealTimeProvider;
 
@@ -795,10 +798,10 @@ private void SendBatchedMessages(SendTarget sendTarget, BatchedSendQueue queue)
             }
 
             var mtu = 0;
-            if (NetworkManager)
+            if (m_NetworkManager)
             {
-                var ngoClientId = NetworkManager.ConnectionManager.TransportIdToClientId(sendTarget.ClientId);
-                mtu = NetworkManager.GetPeerMTU(ngoClientId);
+                var ngoClientId = m_NetworkManager.ConnectionManager.TransportIdToClientId(sendTarget.ClientId);
+                mtu = m_NetworkManager.GetPeerMTU(ngoClientId);
             }
 
             new SendBatchedMessagesJob
@@ -947,7 +950,7 @@ private void Update()
                 }
 
 #if MULTIPLAYER_TOOLS_1_0_0_PRE_7
-                if (NetworkManager)
+                if (m_NetworkManager)
                 {
                     ExtractNetworkMetrics();
                 }
@@ -963,16 +966,16 @@ private void OnDestroy()
 #if MULTIPLAYER_TOOLS_1_0_0_PRE_7
         private void ExtractNetworkMetrics()
         {
-            if (NetworkManager.IsServer)
+            if (m_NetworkManager.IsServer)
             {
-                var ngoConnectionIds = NetworkManager.ConnectedClients.Keys;
+                var ngoConnectionIds = m_NetworkManager.ConnectedClients.Keys;
                 foreach (var ngoConnectionId in ngoConnectionIds)
                 {
-                    if (ngoConnectionId == 0 && NetworkManager.IsHost)
+                    if (ngoConnectionId == 0 && m_NetworkManager.IsHost)
                     {
                         continue;
                     }
-                    var transportClientId = NetworkManager.ConnectionManager.ClientIdToTransportId(ngoConnectionId);
+                    var transportClientId = m_NetworkManager.ConnectionManager.ClientIdToTransportId(ngoConnectionId);
                     ExtractNetworkMetricsForClient(transportClientId);
                 }
             }
@@ -992,10 +995,10 @@ private void ExtractNetworkMetricsForClient(ulong transportClientId)
             ExtractNetworkMetricsFromPipeline(m_UnreliableSequencedFragmentedPipeline, networkConnection);
             ExtractNetworkMetricsFromPipeline(m_ReliableSequencedPipeline, networkConnection);
 
-            var rttValue = NetworkManager.IsServer ? 0 : ExtractRtt(networkConnection);
+            var rttValue = m_NetworkManager.IsServer ? 0 : ExtractRtt(networkConnection);
             NetworkMetrics.UpdateRttToServer(rttValue);
 
-            var packetLoss = NetworkManager.IsServer ? 0 : ExtractPacketLoss(networkConnection);
+            var packetLoss = m_NetworkManager.IsServer ? 0 : ExtractPacketLoss(networkConnection);
             NetworkMetrics.UpdatePacketLoss(packetLoss);
         }
 
@@ -1199,9 +1202,9 @@ public override ulong GetCurrentRtt(ulong clientId)
             // use the transport client ID) or from a user (which will be using the NGO client ID).
             // So we just try both cases (ExtractRtt returns 0 for invalid connections).
 
-            if (NetworkManager != null)
+            if (m_NetworkManager != null)
             {
-                var transportId = NetworkManager.ConnectionManager.ClientIdToTransportId(clientId);
+                var transportId = m_NetworkManager.ConnectionManager.ClientIdToTransportId(clientId);
 
                 var rtt = ExtractRtt(ParseClientId(transportId));
                 if (rtt > 0)
@@ -1221,14 +1224,14 @@ public override void Initialize(NetworkManager networkManager = null)
         {
             Debug.Assert(sizeof(ulong) == UnsafeUtility.SizeOf<NetworkConnection>(), "Netcode connection id size does not match UTP connection id size");
 
-            NetworkManager = networkManager;
+            m_NetworkManager = networkManager;
 
-            if (NetworkManager && NetworkManager.PortOverride.Overidden)
+            if (m_NetworkManager && m_NetworkManager.PortOverride.Overidden)
             {
-                ConnectionData.Port = NetworkManager.PortOverride.Value;
+                ConnectionData.Port = m_NetworkManager.PortOverride.Value;
             }
 
-            m_RealTimeProvider = NetworkManager ? NetworkManager.RealTimeProvider : new RealTimeProvider();
+            m_RealTimeProvider = m_NetworkManager ? m_NetworkManager.RealTimeProvider : new RealTimeProvider();
 
             m_NetworkSettings = new NetworkSettings(Allocator.Persistent);
 
@@ -1322,7 +1325,7 @@ public override void Send(ulong clientId, ArraySegment<byte> payload, NetworkDel
                     // provide any reliability guarantees anymore. Disconnect the client since at
                     // this point they're bound to become desynchronized.
 
-                    var ngoClientId = NetworkManager?.ConnectionManager.TransportIdToClientId(clientId) ?? clientId;
+                    var ngoClientId = m_NetworkManager?.ConnectionManager.TransportIdToClientId(clientId) ?? clientId;
                     Debug.LogError($"Couldn't add payload of size {payload.Count} to reliable send queue. " +
                         $"Closing connection {ngoClientId} as reliability guarantees can't be maintained.");
 
@@ -1479,7 +1482,7 @@ private void ConfigureSimulatorForUtp1()
 
         protected override NetworkTopologyTypes OnCurrentTopology()
         {
-            return NetworkManager != null ? NetworkManager.NetworkConfig.NetworkTopology : NetworkTopologyTypes.ClientServer;
+            return m_NetworkManager != null ? m_NetworkManager.NetworkConfig.NetworkTopology : NetworkTopologyTypes.ClientServer;
         }
 
         private string m_ServerPrivateKey;
@@ -1555,7 +1558,7 @@ public void CreateDriver(UnityTransport transport, out NetworkDriver driver,
                 heartbeatTimeoutMS: transport.m_HeartbeatTimeoutMS);
 
 #if UNITY_WEBGL && !UNITY_EDITOR
-            if (NetworkManager.IsServer && m_ProtocolType != ProtocolType.RelayUnityTransport)
+            if (m_NetworkManager.IsServer && m_ProtocolType != ProtocolType.RelayUnityTransport)
             {
                 throw new Exception("WebGL as a server is not supported by Unity Transport, outside the Editor.");
             }
@@ -1577,7 +1580,7 @@ public void CreateDriver(UnityTransport transport, out NetworkDriver driver,
                 }
                 else
                 {
-                    if (NetworkManager.IsServer)
+                    if (m_NetworkManager.IsServer)
                     {
                         if (string.IsNullOrEmpty(m_ServerCertificate) || string.IsNullOrEmpty(m_ServerPrivateKey))
                         {