zarusz · zarusz · Apr 8, 2024 · Apr 8, 2024
diff --git a/docs/serialization.md b/docs/serialization.md
@@ -175,21 +175,27 @@ The Hybrid plugin allows to have multiple serialization formats on one message b
 To use it install the nuget package `SlimMessageBus.Host.Serialization.Hybrid` and then configure the bus:
 
 ```cs
-services.AddSlimMessageBus(mbb => 
-{
-   // serializer 1
-   var avroSerializer = new AvroMessageSerializer();
-
-   // serializer 2
-   var jsonSerializer = new JsonMessageSerializer();
-
-   // Note: Certain messages will be serialized by the Avro serializer, other using the Json serializer
-   mbb.AddHybridSerializer(new Dictionary<IMessageSerializer, Type[]>
-   {
-      [jsonSerializer] = new[] { typeof(SubtractCommand) }, // the first one will be the default serializer, no need to declare types here
-      [avroSerializer] = new[] { typeof(AddCommand), typeof(MultiplyRequest), typeof(MultiplyResponse) },
-   }, defaultMessageSerializer: jsonSerializer);
-});
+    services
+       .AddSlimMessageBus(mbb =>
+        {
+            mbb
+                .AddHybridSerializer(
+                    builder => {
+                        builder
+                            .AsDefault()
+                            .AddJsonSerializer();
+
+                        builder
+                            .For(typeof(Message1), typeof(Message2))
+                            .AddAvroSerializer();
+
+                        builder
+                            .For(typeof(Message3))
+                            .AddGoogleProtobufSerializer();
+                    })
+                ...
+        } 
 ```
 
 The routing to the proper serializer happens based on message type. When a type cannot be matched the default serializer will be used.
+The routing to the proper serializer happens based on message type. When a type cannot be matched the default serializer will be used.
diff --git a/src/Samples/Sample.Serialization.ConsoleApp/Program.cs b/src/Samples/Sample.Serialization.ConsoleApp/Program.cs
@@ -39,44 +39,26 @@ static async Task Main(string[] args) => await Host.CreateDefaultBuilder(args)
             Secrets.Load(@"..\..\..\..\..\secrets.txt");
 
             services.AddHostedService<MainProgram>();
-
-            // alternatively a simpler approach, but using the slower ReflectionMessageCreationStategy and ReflectionSchemaLookupStrategy
-            var avroSerializer = new AvroMessageSerializer();
-
-            // Avro serialized using the AvroConvert library - no schema generation neeeded upfront.
-            var jsonSerializer = new JsonMessageSerializer();
-
             services
                 .AddSlimMessageBus(mbb =>
                 {
                     // Note: remember that Memory provider does not support req-resp yet.
-                    var provider = Provider.Redis;
-
-                    /*
-                    var sl = new DictionarySchemaLookupStrategy();
-                    /// register all your types
-                    sl.Add(typeof(AddCommand), AddCommand._SCHEMA);
-                    sl.Add(typeof(MultiplyRequest), MultiplyRequest._SCHEMA);
-                    sl.Add(typeof(MultiplyResponse), MultiplyResponse._SCHEMA);
-
-                    var mf = new DictionaryMessageCreationStategy();
-                    /// register all your types
-                    mf.Add(typeof(AddCommand), () => new AddCommand());
-                    mf.Add(typeof(MultiplyRequest), () => new MultiplyRequest());
-                    mf.Add(typeof(MultiplyResponse), () => new MultiplyResponse());
-
-                    // longer approach, but should be faster as it's not using reflection
-                    var avroSerializer = new AvroMessageSerializer(mf, sl);
-                    */
+                    var provider = Provider.Memory;
 
                     mbb
                         .AddServicesFromAssemblyContaining<AddCommandConsumer>()
-                        // Note: Certain messages will be serialized by one Avro serializer, other using the Json serializer
-                        .AddHybridSerializer(new Dictionary<IMessageSerializer, Type[]>
+
+                        // Note: Certain messages will be serialized by the Avro serializer, others will fall back to the Json serializer (the default)
+                        .AddHybridSerializer(builder =>
                         {
-                            [jsonSerializer] = new[] { typeof(SubtractCommand) }, // the first one will be the default serializer, no need to declare types here
-                            [avroSerializer] = new[] { typeof(AddCommand), typeof(MultiplyRequest), typeof(MultiplyResponse) },
-                        }, defaultMessageSerializer: jsonSerializer)
+                            builder
+                                .AsDefault()
+                                .AddJsonSerializer();
+
+                            builder
+                                .For(typeof(AddCommand), typeof(MultiplyRequest), typeof(MultiplyResponse))
+                                .AddAvroSerializer();
+                        })
 
                         .Produce<AddCommand>(x => x.DefaultTopic("AddCommand"))
                         .Consume<AddCommand>(x => x.Topic("AddCommand").WithConsumer<AddCommandConsumer>())

diff --git a/src/SlimMessageBus.Host.Configuration/Builders/ISerializationBuilder.cs b/src/SlimMessageBus.Host.Configuration/Builders/ISerializationBuilder.cs
@@ -1,5 +1,6 @@
 namespace SlimMessageBus.Host;
 
-public interface ISerializationBuilder : IHasPostConfigurationActions
+public interface ISerializationBuilder
 {
+    void RegisterSerializer<TMessageSerializer>(Action<IServiceCollection> services) where TMessageSerializer : class, IMessageSerializer;
 }
diff --git a/src/SlimMessageBus.Host.Configuration/Builders/MessageBusBuilder.cs b/src/SlimMessageBus.Host.Configuration/Builders/MessageBusBuilder.cs
@@ -1,6 +1,8 @@
 namespace SlimMessageBus.Host;
 
-public class MessageBusBuilder : ISerializationBuilder
+using Microsoft.Extensions.DependencyInjection.Extensions;
+
+public class MessageBusBuilder : IHasPostConfigurationActions, ISerializationBuilder
 {
     /// <summary>
     /// Parent bus builder.
@@ -224,6 +226,13 @@
         return this;
     }
 
+    public void RegisterSerializer<TMessageSerializer>(Action<IServiceCollection> services)
+        where TMessageSerializer : class, IMessageSerializer
+    {
+        PostConfigurationActions.Add(services);
+        PostConfigurationActions.Add(services => services.TryAddSingleton<IMessageSerializer>(sp => sp.GetRequiredService<TMessageSerializer>()));
+    }
+
     public MessageBusBuilder WithDependencyResolver(IServiceProvider serviceProvider)
     {
         Settings.ServiceProvider = serviceProvider ?? throw new ArgumentNullException(nameof(serviceProvider));
@@ -264,7 +273,7 @@
     public MessageBusBuilder WithMessageTypeResolver<T>() => WithMessageTypeResolver(typeof(T));
 
     /// <summary>
-    /// Hook called whenver message is being produced. Can be used to change message headers.
+    /// Hook called whenever message is being produced. Can be used to change message headers.
     /// </summary>
     /// <param name="executePrevious">Should the previously set modifier be executed as well?</param>
     public MessageBusBuilder WithHeaderModifier(MessageHeaderModifier<object> headerModifier, bool executePrevious = true)
@@ -325,7 +334,7 @@
            child.MergeFrom(Settings);
        }

        builderAction?.Invoke(child);

        return this;
    }
@@ -338,5 +347,5 @@
             throw new ConfigurationMessageBusException($"{busName}The bus provider was not configured. Check the MessageBus configuration and ensure the has the '.WithProviderXxx()' setting for one of the available transports.");
         }
         return BusFactory(Settings);
-    }
+    }
 }
diff --git a/src/SlimMessageBus.Host.Serialization.Avro/SerializationBuilderExtensions.cs b/src/SlimMessageBus.Host.Serialization.Avro/SerializationBuilderExtensions.cs
@@ -18,10 +18,9 @@ public static class SerializationBuilderExtensions
     public static TBuilder AddAvroSerializer<TBuilder>(this TBuilder builder, IMessageCreationStrategy messageCreationStrategy, ISchemaLookupStrategy schemaLookupStrategy)
         where TBuilder : ISerializationBuilder
     {
-        builder.PostConfigurationActions.Add(services =>
+        builder.RegisterSerializer<AvroMessageSerializer>(services =>
         {
             services.TryAddSingleton(svp => new AvroMessageSerializer(svp.GetRequiredService<ILoggerFactory>(), messageCreationStrategy, schemaLookupStrategy));
-            services.TryAddSingleton<IMessageSerializer>(svp => svp.GetRequiredService<AvroMessageSerializer>());
         });
         return builder;
     }
@@ -35,10 +34,9 @@ public static TBuilder AddAvroSerializer<TBuilder>(this TBuilder builder, IMessa
     public static TBuilder AddAvroSerializer<TBuilder>(this TBuilder builder)
         where TBuilder : ISerializationBuilder
     {
-        builder.PostConfigurationActions.Add(services =>
+        builder.RegisterSerializer<AvroMessageSerializer>(services =>
         {
             services.TryAddSingleton(svp => new AvroMessageSerializer(svp.GetRequiredService<ILoggerFactory>()));
-            services.TryAddSingleton<IMessageSerializer>(svp => svp.GetRequiredService<AvroMessageSerializer>());
         });
         return builder;
     }

diff --git a/src/SlimMessageBus.Host.Serialization.GoogleProtobuf/SerializationBuilderExtensions.cs b/src/SlimMessageBus.Host.Serialization.GoogleProtobuf/SerializationBuilderExtensions.cs
@@ -17,10 +17,9 @@ public static class SerializationBuilderExtensions
     public static TBuilder AddGoogleProtobufSerializer<TBuilder>(this TBuilder builder, IMessageParserFactory messageParserFactory = null)
         where TBuilder : ISerializationBuilder
     {
-        builder.PostConfigurationActions.Add(services =>
+        builder.RegisterSerializer<GoogleProtobufMessageSerializer>(services =>
         {
             services.TryAddSingleton(svp => new GoogleProtobufMessageSerializer(svp.GetRequiredService<ILoggerFactory>(), messageParserFactory));
-            services.TryAddSingleton<IMessageSerializer>(svp => svp.GetRequiredService<GoogleProtobufMessageSerializer>());
         });
         return builder;
     }

diff --git a/src/SlimMessageBus.Host.Serialization.Hybrid/HybridMessageSerializer.cs b/src/SlimMessageBus.Host.Serialization.Hybrid/HybridMessageSerializer.cs
@@ -8,10 +8,12 @@
 public class HybridMessageSerializer : IMessageSerializer
 {
     private readonly ILogger _logger;
-    private readonly IList<IMessageSerializer> _serializers = new List<IMessageSerializer>();
-    private readonly IDictionary<Type, IMessageSerializer> _serializerByType = new Dictionary<Type, IMessageSerializer>();
+    private readonly Dictionary<Type, IMessageSerializer> _serializerByType = [];
+
     public IMessageSerializer DefaultSerializer { get; set; }
 
+    internal IReadOnlyDictionary<Type, IMessageSerializer> SerializerByType => _serializerByType;
+
     public HybridMessageSerializer(ILogger<HybridMessageSerializer> logger, IDictionary<IMessageSerializer, Type[]> registration, IMessageSerializer defaultMessageSerializer = null)
     {
         _logger = logger;
@@ -24,12 +26,14 @@ public HybridMessageSerializer(ILogger<HybridMessageSerializer> logger, IDiction
 
     public void Add(IMessageSerializer serializer, params Type[] supportedTypes)
     {
-        if (_serializers.Count == 0 && DefaultSerializer == null)
-        {
-            DefaultSerializer = serializer;
-        }
+#if NETSTANDARD2_0
+        if (serializer is null) throw new ArgumentNullException(nameof(serializer));
+#else
+        ArgumentNullException.ThrowIfNull(serializer);
+#endif
+
+        DefaultSerializer ??= serializer;
 
-        _serializers.Add(serializer);
         foreach (var type in supportedTypes)
         {
             _serializerByType.Add(type, serializer);
@@ -38,19 +42,19 @@ public void Add(IMessageSerializer serializer, params Type[] supportedTypes)
 
     protected virtual IMessageSerializer MatchSerializer(Type t)
     {
-        if (_serializers.Count == 0)
-        {
-            throw new InvalidOperationException("No serializers registered.");
-        }
-
         if (!_serializerByType.TryGetValue(t, out var serializer))
         {
-            // use first as default
-            _logger.LogTrace("Serializer for type {0} not registered, will use default serializer", t);
+            _logger.LogTrace("Serializer for type {MessageType} not registered, will use default serializer", t);
+
+            if (DefaultSerializer == null)
+            {
+                throw new InvalidOperationException("No serializers registered.");
+            }
+
             serializer = DefaultSerializer;
         }
 
-        _logger.LogDebug("Serializer for type {0} will be {1}", t, serializer);
+        _logger.LogDebug("Serializer for type {MessageType} will be {Serializer}", t, serializer);
         return serializer;
     }
 

diff --git a/src/SlimMessageBus.Host.Serialization.Hybrid/SerializationBuilderExtensions.cs b/src/SlimMessageBus.Host.Serialization.Hybrid/SerializationBuilderExtensions.cs
@@ -18,11 +18,120 @@
     public static TBuilder AddHybridSerializer<TBuilder>(this TBuilder builder, IDictionary<IMessageSerializer, Type[]> registration, IMessageSerializer defaultMessageSerializer)
         where TBuilder : ISerializationBuilder
     {
-        builder.PostConfigurationActions.Add(services =>
+        builder.RegisterSerializer<HybridMessageSerializer>(services =>
         {
             services.TryAddSingleton(svp => new HybridMessageSerializer(svp.GetRequiredService<ILogger<HybridMessageSerializer>>(), registration, defaultMessageSerializer));
-            services.TryAddSingleton<IMessageSerializer>(svp => svp.GetRequiredService<HybridMessageSerializer>());
         });
         return builder;
     }
+
+    /// <summary>
+    /// Registers the <see cref="IMessageSerializer"/> with implementation as <see cref="HybridMessageSerializer"/> using serializers as registered in the <see cref="IServiceCollection"/>.
+    /// </summary>
+    /// <param name="mbb"><see cref="MessageBusBuilder"/></param>
+    /// <param name="registration">Action to register serializers for dependency injection resolution.</param>
+    /// <returns><see cref="MessageBusBuilder"/></returns>
+    public static MessageBusBuilder AddHybridSerializer(this MessageBusBuilder mbb, Action<HybridSerializerOptionsBuilder> registration)
+    {
+        var builder = new HybridSerializerOptionsBuilder();
+        registration(builder);
+
+        foreach (var action in builder.ServiceRegistrations)
+        {
+            mbb.PostConfigurationActions.Add(action);
+        }
+
+        mbb.PostConfigurationActions.Add(services =>
+        {
+            services.TryAddSingleton(svp =>
+            {
+                if (services.Count(x => x.ServiceType == typeof(IMessageSerializer)) > 1)
+                {
+                    throw new NotSupportedException($"Registering instances of {nameof(IMessageSerializer)} outside of {nameof(AddHybridSerializer)} is not supported.");
+                }
+
+                var defaultMessageSerializer = builder.DefaultSerializer != null ? (IMessageSerializer)svp.GetRequiredService(builder.DefaultSerializer) : null;
+                var typeRegistrations = builder.TypeRegistrations.ToDictionary(x => (IMessageSerializer)svp.GetRequiredService(x.Key), x => x.Value);
+                return new HybridMessageSerializer(svp.GetRequiredService<ILogger<HybridMessageSerializer>>(), typeRegistrations, defaultMessageSerializer);
+            });
+
+            services.AddSingleton<IMessageSerializer>(svp => svp.GetRequiredService<HybridMessageSerializer>());
+        });
+        return mbb;
+    }
+
+    public sealed class HybridSerializerOptionsBuilder
+    {
+        private readonly List<SerializerConfiguration> _configurations = [];
+
+        public Type DefaultSerializer
+        {
+            get
+            {
+                return _configurations
+                    .OfType<DefaultSerializerConfiguration>()
+                    .LastOrDefault(x => x.IsValid)
+                    .Type;
+            }
+        }
+
+        public IReadOnlyList<Action<IServiceCollection>> ServiceRegistrations
+        {
+            get
+            {
+                return _configurations
+                    .Where(x => x.IsValid)
+                    .Select(x => x.Action)
+                    .ToList();
+            }
+        }
+
+        public IReadOnlyDictionary<Type, Type[]> TypeRegistrations
+        {
+            get
+            {
+                return _configurations
+                    .OfType<ForSerializerConfiguration>()
+                    .Where(x => x.IsValid)
+                    .ToDictionary(x => x.Type, x => x.Types);
+            }
+        }
+
+        public ISerializationBuilder AsDefault()
+        {
+            var configuration = new DefaultSerializerConfiguration();
+            this._configurations.Add(configuration);
+            return configuration;
+        }
+
+        public ISerializationBuilder For(params Type[] types)
+        {
+            var configuration = new ForSerializerConfiguration(types);
+            this._configurations.Add(configuration);
+            return configuration;
+        }
+
+        public abstract class SerializerConfiguration : ISerializationBuilder
+        {
+            public Action<IServiceCollection> Action { get; private set; }
+            public bool IsValid => Type != null;
+            public Type Type { get; private set; } = null;
+
+            public void RegisterSerializer<TMessageSerializer>(Action<IServiceCollection> services)
+                where TMessageSerializer : class, IMessageSerializer
+            {
+                Type = typeof(TMessageSerializer);
+                Action = services;
+            }
+        }
+
+        public class ForSerializerConfiguration(Type[] types) : SerializerConfiguration, ISerializationBuilder
+        {
+            public Type[] Types { get; } = types;
+        }
+
+        public class DefaultSerializerConfiguration : SerializerConfiguration, ISerializationBuilder
+        {
+        }
+    }
 }