More structed connection metadata

src/Microsoft.AspNetCore.Sockets/Connection.cs

@@ -12,6 +12,6 @@ namespace Microsoft.AspNetCore.Sockets
         public string ConnectionId { get; set; }
         public ClaimsPrincipal User { get; set; }
         public IChannel Channel { get; set; }
-        public IDictionary<string, object> Metadata { get; } = new Dictionary<string, object>();
+        public ConnectionMetadata Metadata { get; } = new ConnectionMetadata();
     }
 }

src/Microsoft.AspNetCore.Sockets/ConnectionMetadata.cs

@@ -0,0 +1,24 @@
+
+using System.Collections.Generic;
+
+namespace Microsoft.AspNetCore.Sockets
+{
+    public class ConnectionMetadata
+    {
+        private IDictionary<string, object> _metadata = new Dictionary<string, object>();
+
+        public Format Format { get; set; } = Format.Text;
+
+        public object this[string key]
+        {
+            get
+            {
+                return _metadata[key];
+            }
+            set
+            {
+                _metadata[key] = value;
+            }
+        }
+    }
+}

src/Microsoft.AspNetCore.Sockets/Format.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Microsoft.AspNetCore.Sockets
+{
+    public enum Format
+    {
+        Text,
+        Binary
+    }
+}

src/Microsoft.AspNetCore.Sockets/HttpConnectionDispatcher.cs

@@ -46,6 +46,10 @@ namespace Microsoft.AspNetCore.Sockets
 
                 // Get the end point mapped to this http connection
                 var endpoint = (EndPoint)context.RequestServices.GetRequiredService<TEndPoint>();
+                var format =
+                    string.Equals(context.Request.Query["format"], "binary", StringComparison.OrdinalIgnoreCase)
+                        ? Format.Binary
+                        : Format.Text;
 
                 // Server sent events transport
                 if (context.Request.Path.StartsWithSegments(path + "/sse"))
@@ -54,6 +58,7 @@ namespace Microsoft.AspNetCore.Sockets
                     var connectionState = GetOrCreateConnection(context);
                     connectionState.Connection.User = context.User;
                     connectionState.Connection.Metadata["transport"] = "sse";
+                    connectionState.Connection.Metadata.Format = format;
                     var sse = new ServerSentEvents(connectionState.Connection);
 
                     // Register this transport for disconnect
@@ -82,6 +87,7 @@ namespace Microsoft.AspNetCore.Sockets
                     var connectionState = GetOrCreateConnection(context);
                     connectionState.Connection.User = context.User;
                     connectionState.Connection.Metadata["transport"] = "websockets";
+                    connectionState.Connection.Metadata.Format = format;
                     var ws = new WebSockets(connectionState.Connection);
 
                     // Register this transport for disconnect
@@ -136,6 +142,7 @@ namespace Microsoft.AspNetCore.Sockets
                     if (isNewConnection)
                     {
                         connectionState.Connection.Metadata["transport"] = "poll";
+                        connectionState.Connection.Metadata.Format = format;
                         connectionState.Connection.User = context.User;
                         endpointTask = endpoint.OnConnected(connectionState.Connection);
                         connectionState.Connection.Metadata["endpoint"] = endpointTask;