Added logger structure for route values

Author: kichalla

src/Microsoft.AspNet.Routing/Logging/RouteValuesLogValues.cs

@@ -0,0 +1,31 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Microsoft.Framework.Logging;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Microsoft.AspNet.Routing.Logging
+{
+    public class RouteValuesLogValues : ILogValues
+    {
+        private readonly IDictionary<string, object> _routeValues;
+
+        public RouteValuesLogValues(IDictionary<string, object> routeValues)
+        {
+            _routeValues = routeValues;
+        }
+
+        public IEnumerable<KeyValuePair<string, object>> GetValues()
+        {
+            return _routeValues;
+        }
+
+        public override string ToString()
+        {
+            return string.Format(
+                "Route values: {0}",
+                string.Join(", ", _routeValues.Select(kvp => $"Key={kvp.Key};Value={kvp.Value}")));
+        }
+    }
+}

src/Microsoft.AspNet.Routing/RouteConstraintMatcher.cs

@@ -22,9 +22,18 @@ public static bool Match(IReadOnlyDictionary<string, IRouteConstraint> constrain
                 return true;
             }
 
+            logger.LogVerbose("Verifying route constraints");
+            if(constraints != null && constraints.Count == 0)
+            {
+                logger.LogVerbose("No route constraints found.");
+            }
+
             foreach (var kvp in constraints)
             {
                 var constraint = kvp.Value;
+
+                logger.LogVerbose("Verifying constraint '{RouteConstraint}' for '{RouteKey}'", constraint, kvp.Key);
+
                 if (!constraint.Match(httpContext, route, kvp.Key, routeValues, routeDirection))
                 {
                     if (routeDirection.Equals(RouteDirection.IncomingRequest))

src/Microsoft.AspNet.Routing/Template/TemplateRoute.cs

@@ -122,7 +122,7 @@ public async virtual Task RouteAsync([NotNull] RouteContext context)
 
             _logger.LogVerbose(
                     "Request successfully matched the template of the route with name '{RouteName}' and template" +
-                    " '{RouteTemplate}'. Verifying constraints now...",
+                    " '{RouteTemplate}'.",
                     Name,
                     RouteTemplate);
 
@@ -133,6 +133,8 @@ public async virtual Task RouteAsync([NotNull] RouteContext context)
             newRouteData.Routers.Add(_target);
             MergeValues(newRouteData.Values, values);
 
+            _logger.LogVerbose(new RouteValuesLogValues(newRouteData.Values));
+            
             if (!RouteConstraintMatcher.Match(
                 Constraints,
                 newRouteData.Values,