Fix ENet network driver to use 3 separate channels for different packet types

Source/Engine/Networking/Drivers/ENetDriver.cpp

@@ -10,6 +10,7 @@
 #include "Engine/Networking/NetworkStats.h"
 #include "Engine/Core/Log.h"
 #include "Engine/Core/Collections/Array.h"
+#include "Engine/Profiler/ProfilerCPU.h"
 #define ENET_IMPLEMENTATION
 #define _WINSOCK_DEPRECATED_NO_WARNINGS
 #include <enet/enet.h>
@@ -25,14 +26,34 @@ ENetPacketFlag ChannelTypeToPacketFlag(const NetworkChannelType channel)
         flag |= ENET_PACKET_FLAG_RELIABLE;
 
     // Use unsequenced flag when the flag is unreliable. We have to sequence all other packets.
+    // Note: ENet has no "unreliable ordered" channel type, so we have to use reliable for that.
     if (channel == NetworkChannelType::Unreliable)
         flag |= ENET_PACKET_FLAG_UNSEQUENCED;
 
-    // Note that all reliable channels are exactly the same. TODO: How to handle unordered reliable packets...?
-
     return static_cast<ENetPacketFlag>(flag);
 }
 
+// Unreliable - 0
+// UnreliableOrdered - 1
+// Reliable/ReliableOrdered - 2
+#define ENET_CHANNEL_COUNT 3
+
+enet_uint8 ChannelTypeToChannelIndex(const NetworkChannelType channel)
+{
+    switch (channel)
+    {
+    case NetworkChannelType::Unreliable:
+        return 0;
+    case NetworkChannelType::UnreliableOrdered:
+        return 1;
+    case NetworkChannelType::Reliable:
+    case NetworkChannelType::ReliableOrdered:
+        return 2;
+    default:
+        return 0;
+    }
+}
+
 void SendPacketToPeer(ENetPeer* peer, const NetworkChannelType channelType, const NetworkMessage& message)
 {
     // Covert our channel type to the internal ENet packet flags
@@ -45,7 +66,7 @@ void SendPacketToPeer(ENetPeer* peer, const NetworkChannelType channelType, cons
     ENetPacket* packet = enet_packet_create(message.Buffer, message.Position, flag);
 
     // And send it!
-    enet_peer_send(peer, 0, packet);
+    enet_peer_send(peer, ChannelTypeToChannelIndex(channelType), packet);
 
     // TODO: To reduce latency, we can use `enet_host_flush` to flush all packets. Maybe some API, like NetworkManager::FlushQueues()?
 }
@@ -57,6 +78,7 @@ ENetDriver::ENetDriver(const SpawnParams& params)
 
 bool ENetDriver::Initialize(NetworkPeer* host, const NetworkConfig& config)
 {
+    PROFILE_CPU();
     _networkHost = host;
     _config = config;
     _peerMap.Clear();
@@ -73,6 +95,7 @@ bool ENetDriver::Initialize(NetworkPeer* host, const NetworkConfig& config)
 
 void ENetDriver::Dispose()
 {
+    PROFILE_CPU();
     if (_peer)
         enet_peer_disconnect_now(_peer, 0);
     enet_host_destroy(_host);
@@ -89,6 +112,7 @@ void ENetDriver::Dispose()
 
 bool ENetDriver::Listen()
 {
+    PROFILE_CPU();
     ENetAddress address = { 0 };
     address.port = _config.Port;
     address.host = ENET_HOST_ANY;
@@ -98,7 +122,7 @@ bool ENetDriver::Listen()
         enet_address_set_host(&address, _config.Address.ToStringAnsi().GetText());
 
     // Create ENet host
-    _host = enet_host_create(&address, _config.ConnectionsLimit, 1, 0, 0);
+    _host = enet_host_create(&address, _config.ConnectionsLimit, ENET_CHANNEL_COUNT, 0, 0);
     if (_host == nullptr)
     {
         LOG(Error, "Failed to initialize ENet host!");
@@ -111,6 +135,7 @@ bool ENetDriver::Listen()
 
 bool ENetDriver::Connect()
 {
+    PROFILE_CPU();
     LOG(Info, "Connecting using ENet...");
 
     ENetAddress address = { 0 };
@@ -118,7 +143,7 @@ bool ENetDriver::Connect()
     enet_address_set_host(&address, _config.Address.ToStringAnsi().GetText());
 
     // Create ENet host
-    _host = enet_host_create(nullptr, 1, 1, 0, 0);
+    _host = enet_host_create(nullptr, 1, ENET_CHANNEL_COUNT, 0, 0);
     if (_host == nullptr)
     {
         LOG(Error, "Failed to initialize ENet host!");
@@ -126,7 +151,7 @@ bool ENetDriver::Connect()
     }
 
     // Create ENet peer/connect to the server
-    _peer = enet_host_connect(_host, &address, 1, 0);
+    _peer = enet_host_connect(_host, &address, ENET_CHANNEL_COUNT, 0);
     if (_peer == nullptr)
     {
         LOG(Error, "Failed to create ENet host!");
@@ -139,6 +164,7 @@ bool ENetDriver::Connect()
 
 void ENetDriver::Disconnect()
 {
+    PROFILE_CPU();
     if (_peer)
     {
         enet_peer_disconnect_now(_peer, 0);
@@ -149,6 +175,7 @@ void ENetDriver::Disconnect()
 
 void ENetDriver::Disconnect(const NetworkConnection& connection)
 {
+    PROFILE_CPU();
     const int connectionId = connection.ConnectionId;
     ENetPeer* peer;
     if (_peerMap.TryGet(connectionId, peer))
@@ -164,6 +191,7 @@ void ENetDriver::Disconnect(const NetworkConnection& connection)
 
 bool ENetDriver::PopEvent(NetworkEvent& eventPtr)
 {
+    PROFILE_CPU();
     ASSERT(_host);
     ENetEvent event;
     const int result = enet_host_service(_host, &event, 0);
@@ -215,12 +243,14 @@ bool ENetDriver::PopEvent(NetworkEvent& eventPtr)
 
 void ENetDriver::SendMessage(const NetworkChannelType channelType, const NetworkMessage& message)
 {
+    PROFILE_CPU();
     ASSERT(!IsServer());
     SendPacketToPeer(_peer, channelType, message);
 }
 
 void ENetDriver::SendMessage(NetworkChannelType channelType, const NetworkMessage& message, NetworkConnection target)
 {
+    PROFILE_CPU();
     ASSERT(IsServer());
     ENetPeer* peer;
     if (_peerMap.TryGet(target.ConnectionId, peer) && peer && peer->state == ENET_PEER_STATE_CONNECTED)
@@ -231,6 +261,7 @@ void ENetDriver::SendMessage(NetworkChannelType channelType, const NetworkMessag
 
 void ENetDriver::SendMessage(const NetworkChannelType channelType, const NetworkMessage& message, const Array<NetworkConnection, HeapAllocation>& targets)
 {
+    PROFILE_CPU();
     ASSERT(IsServer());
     ENetPeer* peer;
     for (NetworkConnection target : targets)

Source/Engine/Networking/NetworkPeer.cpp

@@ -141,7 +141,7 @@ NetworkMessage NetworkPeer::CreateMessage()
 {
     CHECK_RETURN(MessagePool.HasItems(), NetworkMessage());
     const uint32 messageId = MessagePool.Pop();
-    uint8* messageBuffer = GetMessageBuffer(messageId);
+    uint8* messageBuffer = (uint8*)MessageBuffer + Config.MessageSize * messageId;
     return NetworkMessage(messageBuffer, Config.MessageSize, messageId);
 }
 

Source/Engine/Networking/NetworkPeer.h

@@ -144,12 +144,6 @@ public:
         return NetworkDriver != nullptr && HostId >= 0;
     }
 
-    uint8* GetMessageBuffer(const uint32 messageId) const
-    {
-        // Calculate and return the buffer slice using previously calculated slice.
-        return MessageBuffer + Config.MessageSize * messageId;
-    }
-
 public:
     FORCE_INLINE bool operator==(const NetworkPeer& other) const
     {