feat: snapshot spawn pre-requisite (#1166)

* feat: snapshot. Enabling spawns via snapshot by default

* feat: snapshot. Fixing the snapshot spawns mechanism to not rely on Singleton

* feat: snapshot. Removing the default on for snapshot spawns

Author: jeffreyrainy

com.unity.netcode.gameobjects/Runtime/Messaging/IInternalMessageHandler.cs

@@ -17,5 +17,6 @@ internal interface IInternalMessageHandler
         void HandleUnnamedMessage(ulong clientId, Stream stream);
         void HandleNamedMessage(ulong clientId, Stream stream);
         void HandleNetworkLog(ulong clientId, Stream stream);
+        void HandleSnapshot(ulong clientId, Stream messageStream);
     }
 }

com.unity.netcode.gameobjects/Runtime/Messaging/InternalMessageHandler.cs

@@ -306,9 +306,9 @@ public void HandleNetworkLog(ulong clientId, Stream stream)
             }
         }
 
-        internal static void HandleSnapshot(ulong clientId, Stream messageStream)
+        public void HandleSnapshot(ulong clientId, Stream messageStream)
         {
-            NetworkManager.Singleton.SnapshotSystem.ReadSnapshot(clientId, messageStream);
+            m_NetworkManager.SnapshotSystem.ReadSnapshot(clientId, messageStream);
         }
     }
 }

com.unity.netcode.gameobjects/Runtime/Messaging/MessageQueue/MessageQueueProcessor.cs

@@ -106,7 +106,7 @@ public void ProcessMessage(in MessageFrameItem item)
 
                         break;
                     case MessageQueueContainer.MessageType.SnapshotData:
-                        InternalMessageHandler.HandleSnapshot(item.NetworkId, item.NetworkBuffer);
+                        m_NetworkManager.MessageHandler.HandleSnapshot(item.NetworkId, item.NetworkBuffer);
                         break;
                     case MessageQueueContainer.MessageType.NetworkVariableDelta:
                         m_NetworkManager.MessageHandler.HandleNetworkVariableDelta(item.NetworkId, item.NetworkBuffer);

com.unity.netcode.gameobjects/Runtime/Profiling/InternalMessageHandlerProfilingDecorator.cs

@@ -93,6 +93,15 @@ public void HandleNetworkVariableDelta(ulong clientId, Stream stream)
             m_HandleNetworkVariableDelta.End();
         }
 
+        public void HandleSnapshot(ulong clientId, Stream stream)
+        {
+            m_HandleNetworkVariableDelta.Begin();
+
+            m_MessageHandler.HandleSnapshot(clientId, stream);
+
+            m_HandleNetworkVariableDelta.End();
+        }
+
         public void MessageReceiveQueueItem(ulong clientId, Stream stream, float receiveTime, MessageQueueContainer.MessageType messageType)
         {
             switch (messageType)

com.unity.netcode.gameobjects/Tests/Editor/DummyMessageHandler.cs

@@ -50,6 +50,8 @@ public void MessageReceiveQueueItem(ulong clientId, Stream stream, float receive
 
         public void HandleNetworkLog(ulong clientId, Stream stream) => VerifyCalled(nameof(HandleNetworkLog));
 
+        public void HandleSnapshot(ulong clientId, Stream stream) => VerifyCalled(nameof(HandleSnapshot));
+
         public void HandleAllClientsSwitchSceneCompleted(ulong clientId, Stream stream) => VerifyCalled(nameof(HandleAllClientsSwitchSceneCompleted));
 
         private void VerifyCalled(string method)