allow socket injection

src/Backdash/Backends/BackendServices.cs

@@ -1,5 +1,6 @@
 using Backdash.Core;
 using Backdash.Network;
+using Backdash.Network.Client;
 using Backdash.Network.Protocol;
 using Backdash.Serialization;
 using Backdash.Sync.Input;
@@ -30,15 +31,20 @@ public BackendServices(RollbackOptions options, SessionServices<TInput, TGameSta
         Random = new DefaultRandomNumberGenerator(services?.Random ?? System.Random.Shared);
         DelayStrategy = DelayStrategyFactory.Create(Random, options.Protocol.DelayStrategy);
         InputGenerator = services?.InputGenerator;
+
         InputSerializer = services?.InputSerializer ?? BinarySerializerFactory
             .FindOrThrow<TInput>(options.NetworkEndianness);
+
         var logWriter = services?.LogWriter is null || options.Log.EnabledLevel is LogLevel.None
             ? new ConsoleTextLogWriter()
             : services.LogWriter;
+
         Logger = new Logger(options.Log, logWriter);
         Clock = new Clock();
         JobManager = new BackgroundJobManager(Logger);
-        ProtocolClientFactory = new ProtocolClientFactory(options, Logger);
+
+        var socketFactory = services?.PeerSocketFactory ?? new PeerSocketFactory();
+        ProtocolClientFactory = new ProtocolClientFactory(options, socketFactory, Logger);
     }
 }
 

src/Backdash/Network/Client/PeerClient.cs

@@ -32,7 +32,7 @@ interface IPeerJobClient<in T> : IBackgroundJob, IPeerClient<T> where T : struct
 
 sealed class PeerClient<T> : IPeerJobClient<T> where T : struct
 {
-    readonly UdpSocket socket;
+    readonly IPeerSocket socket;
     readonly IPeerObserver<T> observer;
     readonly IBinarySerializer<T> serializer;
     readonly Logger logger;
@@ -41,7 +41,7 @@ sealed class PeerClient<T> : IPeerJobClient<T> where T : struct
     public string JobName { get; }
 
     public PeerClient(
-        UdpSocket socket,
+        IPeerSocket socket,
         IBinarySerializer<T> serializer,
         IPeerObserver<T> observer,
         Logger logger,
@@ -120,7 +120,6 @@ async Task ReceiveLoop(CancellationToken ct)
             catch (NetcodeDeserializationException ex)
             {
                 logger.Write(LogLevel.Warning, $"UDP Message error: {ex}");
-                continue;
             }
         }
 
@@ -167,3 +166,33 @@ public void Dispose()
         socket.Dispose();
     }
 }
+
+/// <summary>
+/// Create new instances of <see cref="IPeerClient{T}"/>
+/// </summary>
+public static class PeerClientFactory
+{
+    internal static IPeerClient<T> Create<T>(
+        IPeerSocket socket,
+        IBinarySerializer<T> serializer,
+        IPeerObserver<T> observer, Logger logger,
+        int maxPacketSize = Max.UdpPacketSize
+    ) where T : struct =>
+        new PeerClient<T>(socket, serializer, observer, logger, maxPacketSize);
+
+    /// <summary>
+    ///  Creates new <see cref="IPeerClient{T}"/>
+    /// </summary>
+    public static IPeerClient<T> Create<T>(
+        IPeerSocket socket,
+        IPeerObserver<T> observer,
+        IBinarySerializer<T>? serializer = null,
+        int maxPacketSize = Max.UdpPacketSize
+    ) where T : struct =>
+        Create(socket,
+            serializer ?? BinarySerializerFactory.FindOrThrow<T>(),
+            observer,
+            Logger.CreateConsoleLogger(LogLevel.None),
+            maxPacketSize
+        );
+}

src/Backdash/Network/Client/PeerSocket.cs

@@ -0,0 +1,45 @@
+using System.Net;
+using System.Net.Sockets;
+
+namespace Backdash.Network.Client;
+
+/// <summary>
+/// Socket abstraction over peers
+/// </summary>
+public interface IPeerSocket : IDisposable
+{
+    /// <inheritdoc cref="Socket.AddressFamily" />
+    AddressFamily AddressFamily { get; }
+
+    /// <summary>
+    /// Binding port
+    /// </summary>
+    int Port { get; }
+
+    /// <summary>
+    /// Receive bytes from specified remote host
+    /// </summary>
+    ValueTask<int> ReceiveFromAsync(Memory<byte> buffer, SocketAddress address, CancellationToken cancellationToken);
+
+    /// <summary>
+    /// Sends data to the specified remote host.
+    /// </summary>
+    ValueTask<int> SendToAsync(ReadOnlyMemory<byte> buffer, SocketAddress socketAddress,
+        CancellationToken cancellationToken);
+}
+
+/// <summary>
+/// Factory for peer sockets
+/// </summary>
+public interface IPeerSocketFactory
+{
+    /// <summary>
+    /// Creates instance of <see cref="IPeerSocket"/>
+    /// </summary>
+    IPeerSocket Create(int port, RollbackOptions options);
+}
+
+sealed class PeerSocketFactory : IPeerSocketFactory
+{
+    public IPeerSocket Create(int port, RollbackOptions options) => new UdpSocket(port, options.UseIPv6);
+}

src/Backdash/Network/Client/UdpSocket.cs

@@ -8,7 +8,7 @@ namespace Backdash.Network.Client;
 /// <summary>
 /// UDP specialized socket interface.
 /// </summary>
-public sealed class UdpSocket : IDisposable
+public sealed class UdpSocket : IPeerSocket
 {
     // ReSharper disable InconsistentNaming
     const uint IOC_IN = 0x80000000;

src/Backdash/Network/Protocol/ProtocolClientFactory.cs

@@ -13,15 +13,14 @@ interface IProtocolClientFactory
 
 sealed class ProtocolClientFactory(
     RollbackOptions options,
+    IPeerSocketFactory socketFactory,
     Logger logger
 ) : IProtocolClientFactory
 {
     public IProtocolClient CreateProtocolClient(int port, IPeerObserver<ProtocolMessage> observer)
     {
-        UdpSocket socket = new UdpSocket(port, options.UseIPv6);
-
         PeerClient<ProtocolMessage> peerClient = new(
-            socket,
+            socketFactory.Create(port, options),
             new ProtocolMessageBinarySerializer(options.NetworkEndianness),
             observer,
             logger,

src/Backdash/SessionServices.cs

@@ -1,4 +1,5 @@
 using Backdash.Core;
+using Backdash.Network.Client;
 using Backdash.Serialization;
 using Backdash.Sync.Input;
 using Backdash.Sync.State;
@@ -46,6 +47,11 @@ public sealed class SessionServices<TInput, TGameState>
     /// </summary>
     public IStateStore<TGameState>? StateStore { get; set; }
 
+    /// <summary>
+    /// State store service for session.
+    /// </summary>
+    public IPeerSocketFactory? PeerSocketFactory { get; set; }
+
     /// <summary>
     /// Default random service
     /// </summary>