new checksum store logic for consitency check

samples/ConsoleGame/Game.cs

@@ -150,11 +150,11 @@ public void TimeSync(FrameSpan framesAhead)
         Thread.Sleep(framesAhead.Duration());
     }
 
-    public void OnPeerEvent(NetcodePlayer player, PeerEventInfo evt)
+    public void OnPeerEvent(NetcodePlayer player, in PeerEventInfo evt)
     {
         Log($"PEER EVENT: {evt} from {player}");
-        if (player.IsSpectator())
-            return;
+        if (player.IsSpectator()) return;
+
         switch (evt.Type)
         {
             case PeerEvent.Connected:

samples/SpaceWar.Lobby/Game1.cs

@@ -33,13 +33,14 @@ protected override void Initialize()
     protected override void LoadContent()
     {
         SpriteBatch = new(GraphicsDevice);
-        SceneManager = new(this, startScene: new ChooseLobbyScene());
 
         Services.AddService(SpriteBatch);
-        Services.AddService(SceneManager);
         Services.AddService(settings);
         Services.AddService(new GameAssets(Content, GraphicsDevice));
         Services.AddService(new LobbyHttpClient(settings));
+
+        SceneManager = new(this, startScene: new ChooseLobbyScene());
+        Services.AddService(SceneManager);
     }
 
     protected override void Update(GameTime gameTime)

samples/SpaceWar.Lobby/Program.cs

@@ -2,6 +2,5 @@
 
 var settings = AppSettings.LoadFromJson("appsettings.json");
 settings.ParseArgs(args);
-
-using var game = new Game1(settings);
+using Game1 game = new(settings);
 game.Run();

samples/SpaceWar.Shared/GameSession.cs

@@ -122,7 +122,7 @@ void UpdateStats()
         nonGameState.StateSize = saved.Size;
     }
 
-    public void OnPeerEvent(NetcodePlayer player, PeerEventInfo evt)
+    public void OnPeerEvent(NetcodePlayer player, in PeerEventInfo evt)
     {
         Log($"=> PEER EVENT: {evt} from {player}");
         if (player.IsSpectator()) return;
@@ -155,6 +155,9 @@ public void OnPeerEvent(NetcodePlayer player, PeerEventInfo evt)
             case PeerEvent.Disconnected:
                 nonGameState.SetConnectState(player, PlayerConnectState.Disconnected);
                 break;
+            case PeerEvent.ChecksumMismatch:
+                Log($"=>  CHECKSUM MISMATCH: {evt.ChecksumMismatch}");
+                break;
         }
     }
 

src/Backdash/Network/PeerConnection.cs

@@ -25,7 +25,7 @@ sealed class PeerConnection<TInput> : IDisposable where TInput : unmanaged
     readonly ProtocolInbox<TInput> inbox;
     readonly ProtocolOutbox outbox;
     readonly ProtocolInputBuffer<TInput> inputBuffer;
-    readonly IStateStore stateStore;
+    readonly ChecksumStore checksumStore;
 
     readonly Timer qualityReportTimer;
     readonly Timer networkStatsTimer;
@@ -45,7 +45,7 @@ public PeerConnection(
         ProtocolInbox<TInput> inbox,
         ProtocolOutbox outbox,
         ProtocolInputBuffer<TInput> inputBuffer,
-        IStateStore stateStore
+        ChecksumStore checksumStore
     )
     {
         this.options = options;
@@ -57,7 +57,7 @@ IStateStore stateStore
         this.inbox = inbox;
         this.outbox = outbox;
         this.inputBuffer = inputBuffer;
-        this.stateStore = stateStore;
+        this.checksumStore = checksumStore;
         disconnectCheckEnabled = options.IsDisconnectTimeoutEnabled();
 
         keepAliveTimer = new(options.KeepAliveInterval);
@@ -269,9 +269,9 @@ bool DispatchInterruptedEvent(TimeSpan timeout)
             if (state.Connection is not { DisconnectNotifySent: false, DisconnectEventSent: false })
                 return false;
 
-            networkEventHandler.OnNetworkEvent(new(ProtocolEvent.NetworkInterrupted, state.Player)
+            networkEventHandler.OnNetworkEvent(state.Player, new(PeerEvent.ConnectionInterrupted)
             {
-                NetworkInterrupted = new()
+                ConnectionInterrupted = new()
                 {
                     DisconnectTimeout = timeout,
                 },
@@ -291,7 +291,7 @@ bool DispatchDisconnectEvent()
                 return false;
 
             state.Connection.DisconnectEventSent = true;
-            networkEventHandler.OnNetworkEvent(ProtocolEvent.Disconnected, state.Player);
+            networkEventHandler.OnNetworkEvent(PeerEvent.Disconnected, state.Player);
 
             return true;
         }
@@ -371,23 +371,19 @@ void UpdateStats(ref ProtocolState.PackagesStats stats)
     void OnConsistencyCheck(object? sender, ElapsedEventArgs e)
     {
         if (state.CurrentStatus is not ProtocolStatus.Running) return;
-
         var lastReceivedFrame = inbox.LastReceivedInput.Frame;
         var checkFrame = lastReceivedFrame.Number - options.ConsistencyCheckDistance;
         if (checkFrame <= 1) return;
 
         state.Consistency.AskedFrame = new(checkFrame);
-        state.Consistency.AskedChecksum = stateStore.GetChecksum(state.Consistency.AskedFrame);
+        state.Consistency.AskedChecksum = checksumStore.Get(state.Consistency.AskedFrame);
 
         if (state.Consistency.AskedFrame.IsNull || state.Consistency.AskedChecksum is 0)
             return;
 
         if (state.Consistency.LastCheck is 0)
             state.Consistency.LastCheck = Stopwatch.GetTimestamp();
 
-        logger.Write(LogLevel.Trace,
-            $"Start consistency check for frame {state.Consistency.AskedFrame} #{state.Consistency.AskedChecksum:x8}");
-
         var elapsed = Stopwatch.GetElapsedTime(state.Consistency.LastCheck);
         if (options.ConsistencyCheckTimeout > TimeSpan.Zero && elapsed > options.ConsistencyCheckTimeout)
         {
@@ -398,7 +394,7 @@ void OnConsistencyCheck(object? sender, ElapsedEventArgs e)
         }
 
         logger.Write(LogLevel.Debug,
-            $"Send consistency request for frame {state.Consistency.AskedFrame.Number} #{state.Consistency.AskedChecksum:x8}");
+            $"Begin consistency-check request for frame {state.Consistency.AskedFrame.Number} #{state.Consistency.AskedChecksum:x8}");
 
         outbox
             .SendMessage(new(MessageType.ConsistencyCheckRequest)

src/Backdash/Network/PeerConnectionFactory.cs

@@ -17,7 +17,7 @@ sealed class PeerConnectionFactory(
     PeerClient<ProtocolMessage> peer,
     ProtocolOptions options,
     TimeSyncOptions timeSyncOptions,
-    IStateStore stateStore
+    ChecksumStore checksumStore
 )
 {
     public PeerConnection<TInput> Create<TInput>(
@@ -31,13 +31,13 @@ public PeerConnection<TInput> Create<TInput>(
         var outbox = new ProtocolOutbox(state, peer, logger);
         var syncManager = new ProtocolSynchronizer(logger, random, state, options, outbox, networkEventHandler);
         var inbox = new ProtocolInbox<TInput>(options, inputSerializer, state, syncManager, outbox,
-            networkEventHandler, inputEventQueue, stateStore, logger);
+            networkEventHandler, inputEventQueue, checksumStore, logger);
         var inputBuffer =
             new ProtocolInputBuffer<TInput>(options, inputSerializer, state, logger, timeSync, outbox, inbox);
 
         PeerConnection<TInput> connection = new(
             options, state, logger, timeSync, networkEventHandler,
-            syncManager, inbox, outbox, inputBuffer, stateStore
+            syncManager, inbox, outbox, inputBuffer, checksumStore
         );
 
         state.StoppingToken.Register(() => connection.Disconnect());

src/Backdash/Network/Protocol/Comm/ProtocolInbox.cs

@@ -27,7 +27,7 @@ sealed class ProtocolInbox<TInput>(
     IMessageSender messageSender,
     IProtocolNetworkEventHandler networkEvents,
     IProtocolInputEventPublisher<TInput> inputEvents,
-    IStateStore stateStore,
+    ChecksumStore checksumStore,
     Logger logger
 ) : IProtocolInbox<TInput> where TInput : unmanaged
 {
@@ -54,7 +54,7 @@ public void OnPeerMessage(ref readonly ProtocolMessage message, in SocketAddress
         {
             if (state.CurrentStatus is not ProtocolStatus.Running)
             {
-                logger.Write(LogLevel.Debug, $"recv skip (not ready): {message} on {state.Player}");
+                logger.Write(LogLevel.Trace, $"recv skip (not ready): {message} on {state.Player}");
                 return;
             }
 
@@ -85,7 +85,7 @@ public void OnPeerMessage(ref readonly ProtocolMessage message, in SocketAddress
             state.Stats.Received.TotalBytes += (ByteSize)bytesReceived;
             if (state.Connection.DisconnectNotifySent && state.CurrentStatus is ProtocolStatus.Running)
             {
-                networkEvents.OnNetworkEvent(ProtocolEvent.NetworkResumed, state.Player);
+                networkEvents.OnNetworkEvent(PeerEvent.ConnectionResumed, state.Player);
                 state.Connection.DisconnectNotifySent = false;
             }
         }
@@ -124,7 +124,7 @@ bool OnInput(in InputMessage msg)
             if (state.CurrentStatus is not ProtocolStatus.Disconnected && !state.Connection.DisconnectEventSent)
             {
                 logger.Write(LogLevel.Information, "Disconnecting endpoint on remote request");
-                networkEvents.OnNetworkEvent(ProtocolEvent.Disconnected, state.Player);
+                networkEvents.OnNetworkEvent(PeerEvent.Disconnected, state.Player);
                 state.Connection.DisconnectEventSent = true;
             }
         }
@@ -186,7 +186,7 @@ bool OnInput(in InputMessage msg)
                 lastReceivedInput.Frame = currentFrame;
                 state.Stats.LastReceivedInputTime = Stopwatch.GetTimestamp();
                 currentFrame++;
-                logger.Write(LogLevel.Debug,
+                logger.Write(LogLevel.Trace,
                     $"Received input: frame {lastReceivedInput.Frame}, sending to emulator queue {state.Player} (ack: {LastAckedFrame})");
                 inputEvents.Publish(new(state.Player, lastReceivedInput));
             }
@@ -236,7 +236,7 @@ bool OnSyncReply(ref readonly ProtocolMessage msg, ref ProtocolMessage replyMsg)
 
         if (!state.Connection.IsConnected)
         {
-            networkEvents.OnNetworkEvent(ProtocolEvent.Connected, state.Player);
+            networkEvents.OnNetworkEvent(PeerEvent.Connected, state.Player);
             state.Connection.IsConnected = true;
         }
 
@@ -254,21 +254,20 @@ bool OnSyncReply(ref readonly ProtocolMessage msg, ref ProtocolMessage replyMsg)
             state.Stats.RoundTripTime = ping;
             lastReceivedInput.ResetFrame();
             state.RemoteSyncNumber = msg.Header.SyncNumber;
-            networkEvents.OnNetworkEvent(new(ProtocolEvent.Synchronized, state.Player)
+            networkEvents.OnNetworkEvent(state.Player, new(PeerEvent.Synchronized)
             {
                 Synchronized = new(ping),
             });
         }
         else
         {
-            networkEvents.OnNetworkEvent(
-                new(ProtocolEvent.Synchronizing, state.Player)
-                {
-                    Synchronizing = new(
+            networkEvents.OnNetworkEvent(state.Player, new(PeerEvent.Synchronizing)
+            {
+                Synchronizing = new(
                         TotalSteps: options.NumberOfSyncRoundTrips,
                         CurrentStep: options.NumberOfSyncRoundTrips - state.Sync.RemainingRoundTrips
                     ),
-                }
+            }
             );
             sync.CreateRequestMessage(ref replyMsg);
         }
@@ -296,7 +295,7 @@ bool OnConsistencyCheckReply(ref readonly ProtocolMessage message)
         var checksum = message.ConsistencyCheckReply.Checksum;
         var localChecksum = state.Consistency.AskedChecksum;
 
-        logger.Write(LogLevel.Debug, $"Received consistency request reply for: {checkFrame} #{checksum:x8}");
+        logger.Write(LogLevel.Debug, $"Reply consistency-check for {checkFrame} #{checksum:x8}");
 
         if (state.Consistency.AskedFrame != checkFrame || localChecksum is 0 || checksum is 0)
         {
@@ -308,11 +307,21 @@ bool OnConsistencyCheckReply(ref readonly ProtocolMessage message)
         {
             logger.Write(LogLevel.Error,
                 $"Invalid remote checksum on frame {checkFrame}, {localChecksum:x8} != {checksum:x8}");
-            state.StoppingTokenSource.Cancel();
+
+            networkEvents.OnNetworkEvent(state.Player, new(PeerEvent.ChecksumMismatch)
+            {
+                ChecksumMismatch = new(
+                        MismatchFrame: checkFrame,
+                        LocalChecksum: localChecksum,
+                        RemoteChecksum: checksum
+                    ),
+            }
+            );
+
             return false;
         }
 
-        logger.Write(LogLevel.Debug, $"Consistency request check for: {checkFrame} OK({checksum:x8})");
+        logger.Write(LogLevel.Debug, $"Finish consistency-check request check for {checkFrame} #{checksum:x8}");
         state.Consistency.LastCheck = Stopwatch.GetTimestamp();
         state.Consistency.AskedFrame = Frame.Null;
         state.Consistency.AskedChecksum = 0;
@@ -323,7 +332,7 @@ bool OnConsistencyCheckReply(ref readonly ProtocolMessage message)
     bool OnConsistencyCheckRequest(ref readonly ProtocolMessage message, ref ProtocolMessage replyMsg)
     {
         var checkFrame = message.ConsistencyCheckRequest.Frame;
-        var checksum = stateStore.GetChecksum(checkFrame);
+        var checksum = checksumStore.Get(checkFrame);
 
         logger.Write(LogLevel.Debug, $"Received consistency request check for: {checkFrame} (reply {checksum:x8})");
 

src/Backdash/Network/Protocol/Comm/ProtocolSynchronizer.cs

@@ -68,7 +68,7 @@ public void Update()
             active = false;
             logger.Write(LogLevel.Warning,
                 $"Fail to sync {state.Player} after {retryCounter} retries");
-            eventHandler.OnNetworkEvent(ProtocolEvent.SyncFailure, state.Player);
+            eventHandler.OnNetworkEvent(PeerEvent.SynchronizationFailure, state.Player);
             return;
         }
 

src/Backdash/Network/Protocol/ProtocolEvent.cs

@@ -2,24 +2,11 @@
 
 namespace Backdash.Network.Protocol;
 
-enum ProtocolEvent : byte
+struct ProtocolEventInfo(NetcodePlayer player, PeerEventInfo eventInfo) : IUtf8SpanFormattable
 {
-    Connected,
-    Synchronizing,
-    Synchronized,
-    SyncFailure,
-    Disconnected,
-    NetworkInterrupted,
-    NetworkResumed,
-}
-
-struct ProtocolEventInfo(ProtocolEvent type, NetcodePlayer player) : IUtf8SpanFormattable
-{
-    public readonly ProtocolEvent Type = type;
-    public NetcodePlayer Player = player;
-    public SynchronizingEventInfo Synchronizing = default;
-    public SynchronizedEventInfo Synchronized = default;
-    public ConnectionInterruptedEventInfo NetworkInterrupted = default;
+    public readonly NetcodePlayer Player = player;
+    public PeerEventInfo EventInfo = eventInfo;
+    public readonly PeerEvent Type => EventInfo.Type;
 
     public readonly bool TryFormat(
         Span<byte> utf8Destination, out int bytesWritten, ReadOnlySpan<char> format,
@@ -29,23 +16,8 @@ public readonly bool TryFormat(
         Utf8StringBuilder writer = new(in utf8Destination, ref bytesWritten);
         if (!writer.Write("P"u8)) return false;
         if (!writer.Write(Player.Index)) return false;
-        if (!writer.Write(" ProtoEvt "u8)) return false;
-        if (!writer.WriteEnum(Type)) return false;
-        if (!writer.Write(":"u8)) return false;
-        switch (Type)
-        {
-            case ProtocolEvent.NetworkInterrupted:
-                return writer.Write("Timeout: "u8)
-                       && writer.Write(NetworkInterrupted.DisconnectTimeout);
-            case ProtocolEvent.Synchronizing when !writer.Write(' '):
-                return false;
-            case ProtocolEvent.Synchronizing:
-                return writer.Write(Synchronizing.CurrentStep)
-                       && writer.Write('/')
-                       &&
-                       writer.Write(Synchronizing.TotalSteps);
-            default:
-                return writer.Write("{}"u8);
-        }
+        if (!writer.Write(" Info: "u8)) return false;
+        if (!writer.Write(EventInfo)) return false;
+        return true;
     }
 }

src/Backdash/Network/ProtocolNetworkEventQueue.cs

@@ -6,7 +6,8 @@ namespace Backdash.Network;
 interface IProtocolNetworkEventHandler : IDisposable
 {
     void OnNetworkEvent(in ProtocolEventInfo evt);
-    void OnNetworkEvent(in ProtocolEvent evt, NetcodePlayer player) => OnNetworkEvent(new(evt, player));
+    void OnNetworkEvent(NetcodePlayer player, PeerEventInfo evt) => OnNetworkEvent(new(player, evt));
+    void OnNetworkEvent(PeerEvent evt, NetcodePlayer player) => OnNetworkEvent(player, new(evt));
 }
 
 sealed class ProtocolNetworkEventQueue : IProtocolNetworkEventHandler

src/Backdash/Options/ProtocolOptions.cs

@@ -143,7 +143,7 @@ internal bool IsDisconnectTimeoutEnabled() =>
     /// <seealso cref="PeerNetworkStats.Send"/>
     /// <seealso cref="PeerNetworkStats.Received"/>
     /// <value>Defaults to <see lanword="true" /></value>
-    public bool NetworkPackageStatsEnabled { get; set; } = false;
+    public bool NetworkPackageStatsEnabled { get; set; }
 
     internal bool IsNetworkPackageStatsEnabled() =>
         NetworkPackageStatsEnabled && NetworkPackageStatsInterval > TimeSpan.Zero;
@@ -165,7 +165,7 @@ internal bool IsNetworkPackageStatsEnabled() =>
 
     /// <summary>
     ///     Offset to be applied to frame on checksum consistency check.
-    ///     The frame sent is (<c>LastReceivedFrame - ConsistencyCheckOffset</c>).
+    ///     The frame sent is (<c>LastAckedFrame - ConsistencyCheckOffset</c>).
     /// </summary>
     /// <value>Defaults to <c>8</c></value>
     /// <seealso cref="ConsistencyCheckTimeout" />
@@ -180,8 +180,15 @@ internal bool IsNetworkPackageStatsEnabled() =>
     /// <value>Defaults to <c>3_000</c> milliseconds</value>
     /// <seealso cref="ConsistencyCheckDistance" />
     /// <seealso cref="ConsistencyCheckTimeout" />
-    public TimeSpan ConsistencyCheckInterval { get; set; } =
-        TimeSpan.FromMilliseconds(3_000);
+    public TimeSpan ConsistencyCheckInterval { get; set; } = TimeSpan.FromSeconds(3);
+
+    /// <summary>
+    ///     The number of checksum frames that will be keep for consistency checks.
+    /// </summary>
+    /// <value>Defaults to <c>180</c></value>
+    /// <seealso cref="ConsistencyCheckTimeout" />
+    /// <seealso cref="ConsistencyCheckInterval" />
+    public int ConsistencyCheckStoreSize { get; set; } = 250;
 
     /// <summary>
     ///     Enable/Disable consistency check.