Add NetworkStream::SenderId to detect message sender during object replication or RPC code

Source/Engine/Networking/Components/NetworkTransform.cpp

@@ -156,7 +156,6 @@ void NetworkTransform::Serialize(NetworkStream* stream)
         transform = Transform::Identity;
 
     // Encode data
-    const NetworkObjectRole role = NetworkReplicator::GetObjectRole(this);
     Data data;
     data.LocalSpace = LocalSpace;
     data.HasSequenceIndex = Mode == ReplicationModes::Prediction;

Source/Engine/Networking/NetworkReplicator.cpp

@@ -147,6 +147,7 @@ struct ReplicateItem
     Guid ObjectId;
     uint16 PartsLeft;
     uint32 OwnerFrame;
+    uint32 OwnerClientId;
     Array<byte> Data;
 };
 
@@ -488,7 +489,7 @@ void DirtyObjectImpl(NetworkReplicatedObject& item, ScriptingObject* obj)
 }
 
 template<typename MessageType>
-ReplicateItem* AddObjectReplicateItem(NetworkEvent& event, const MessageType& msgData, uint16 partStart, uint16 partSize)
+ReplicateItem* AddObjectReplicateItem(NetworkEvent& event, const MessageType& msgData, uint16 partStart, uint16 partSize, uint32 senderClientId)
 {
     // Reuse or add part item
     ReplicateItem* replicateItem = nullptr;
@@ -508,6 +509,7 @@ ReplicateItem* AddObjectReplicateItem(NetworkEvent& event, const MessageType& ms
         replicateItem->ObjectId = msgData.ObjectId;
         replicateItem->PartsLeft = msgData.PartsCount;
         replicateItem->OwnerFrame = msgData.OwnerFrame;
+        replicateItem->OwnerClientId = senderClientId;
         replicateItem->Data.Resize(msgData.DataSize);
     }
 
@@ -521,7 +523,7 @@ ReplicateItem* AddObjectReplicateItem(NetworkEvent& event, const MessageType& ms
     return replicateItem;
 }
 
-void InvokeObjectReplication(NetworkReplicatedObject& item, uint32 ownerFrame, byte* data, uint32 dataSize)
+void InvokeObjectReplication(NetworkReplicatedObject& item, uint32 ownerFrame, byte* data, uint32 dataSize, uint32 senderClientId)
 {
     ScriptingObject* obj = item.Object.Get();
     if (!obj)
@@ -541,6 +543,7 @@ void InvokeObjectReplication(NetworkReplicatedObject& item, uint32 ownerFrame, b
         CachedReadStream = New<NetworkStream>();
     NetworkStream* stream = CachedReadStream;
     stream->Initialize(data, dataSize);
+    stream->SenderId = senderClientId;
 
     // Deserialize object
     const bool failed = NetworkReplicator::InvokeSerializer(obj->GetTypeHandle(), obj, stream, false);
@@ -879,6 +882,7 @@ NetworkStream* NetworkReplicator::BeginInvokeRPC()
     if (CachedWriteStream == nullptr)
         CachedWriteStream = New<NetworkStream>();
     CachedWriteStream->Initialize();
+    CachedWriteStream->SenderId = NetworkManager::LocalClientId;
     return CachedWriteStream;
 }
 
@@ -981,12 +985,9 @@ void NetworkInternal::NetworkReplicatorUpdate()
     ScopeLock lock(ObjectsLock);
     if (Objects.Count() == 0)
         return;
-    if (CachedWriteStream == nullptr)
-        CachedWriteStream = New<NetworkStream>();
     const bool isClient = NetworkManager::IsClient();
     const bool isServer = NetworkManager::IsServer();
     const bool isHost = NetworkManager::IsHost();
-    NetworkStream* stream = CachedWriteStream;
     NetworkPeer* peer = NetworkManager::Peer;
 
     if (!isClient && NewClients.Count() != 0)
@@ -1137,7 +1138,7 @@ void NetworkInternal::NetworkReplicatorUpdate()
                 auto& item = it->Item;
 
                 // Replicate from all collected parts data
-                InvokeObjectReplication(item, e.OwnerFrame, e.Data.Get(), e.Data.Count());
+                InvokeObjectReplication(item, e.OwnerFrame, e.Data.Get(), e.Data.Count(), e.OwnerClientId);
             }
         }
 
@@ -1145,6 +1146,10 @@ void NetworkInternal::NetworkReplicatorUpdate()
     }
 
     // Brute force synchronize all networked objects with clients
+    if (CachedWriteStream == nullptr)
+        CachedWriteStream = New<NetworkStream>();
+    NetworkStream* stream = CachedWriteStream;
+    stream->SenderId = NetworkManager::LocalClientId;
     // TODO: introduce NetworkReplicationHierarchy to optimize objects replication in large worlds (eg. batched culling networked scene objects that are too far from certain client to be relevant)
     // TODO: per-object sync interval (in frames) - could be scaled by hierarchy (eg. game could slow down sync rate for objects far from player)
     for (auto it = Objects.Begin(); it.IsNotEnd(); ++it)
@@ -1305,16 +1310,17 @@ void NetworkInternal::OnNetworkMessageObjectReplicate(NetworkEvent& event, Netwo
     if (client && item.OwnerClientId != client->ClientId)
         return;
 
+    const uint32 senderClientId = client ? client->ClientId : NetworkManager::LocalClientId;
     if (msgData.PartsCount == 1)
     {
         // Replicate
-        InvokeObjectReplication(item, msgData.OwnerFrame, event.Message.Buffer + event.Message.Position, msgData.DataSize);
+        InvokeObjectReplication(item, msgData.OwnerFrame, event.Message.Buffer + event.Message.Position, msgData.DataSize, senderClientId);
     }
     else
     {
         // Add to replication from multiple parts
         const uint16 msgMaxData = peer->Config.MessageSize - sizeof(NetworkMessageObjectReplicate);
-        ReplicateItem* replicateItem = AddObjectReplicateItem(event, msgData, 0, msgMaxData);
+        ReplicateItem* replicateItem = AddObjectReplicateItem(event, msgData, 0, msgMaxData, senderClientId);
         replicateItem->Object = e->Object;
     }
 }
@@ -1327,7 +1333,8 @@ void NetworkInternal::OnNetworkMessageObjectReplicatePart(NetworkEvent& event, N
     if (DespawnedObjects.Contains(msgData.ObjectId))
         return; // Skip replicating not-existing objects
 
-    AddObjectReplicateItem(event, msgData, msgData.PartStart, msgData.PartSize);
+    const uint32 senderClientId = client ? client->ClientId : NetworkManager::LocalClientId;
+    AddObjectReplicateItem(event, msgData, msgData.PartStart, msgData.PartSize, senderClientId);
 }
 
 void NetworkInternal::OnNetworkMessageObjectSpawn(NetworkEvent& event, NetworkClient* client, NetworkPeer* peer)
@@ -1620,6 +1627,7 @@ void NetworkInternal::OnNetworkMessageObjectRpc(NetworkEvent& event, NetworkClie
         if (CachedReadStream == nullptr)
             CachedReadStream = New<NetworkStream>();
         NetworkStream* stream = CachedReadStream;
+        stream->SenderId = client ? client->ClientId : NetworkManager::LocalClientId;
         stream->Initialize(event.Message.Buffer + event.Message.Position, msgData.ArgsSize);
 
         // Execute RPC

Source/Engine/Networking/NetworkStream.h

@@ -23,6 +23,11 @@ private:
 public:
     ~NetworkStream();
 
+    /// <summary>
+    /// The ClientId of the network client that is a data sender. Can be used to detect who send the incoming RPC or replication data. Set to the current client when writing data.
+    /// </summary>
+    API_FIELD(ReadOnly) uint32 SenderId = 0;
+
     /// <summary>
     /// Gets the pointer to the native stream memory buffer.
     /// </summary>