refactor RedisBatch to use new api for emitting il

Author: lucaspimentel

src/Datadog.Trace.ClrProfiler.Managed/Integrations/StackExchange.Redis/RedisBatch.cs

@@ -1,6 +1,8 @@
 using System;
+using System.Reflection;
 using System.Threading.Tasks;
 using Datadog.Trace.ClrProfiler.Emit;
+using Datadog.Trace.Logging;
 
 namespace Datadog.Trace.ClrProfiler.Integrations.StackExchange.Redis
 {
@@ -16,6 +18,8 @@ public static class RedisBatch
         private const string Major1 = "1";
         private const string Major2 = "2";
 
+        private static readonly ILog Log = LogProvider.GetLogger(typeof(RedisBatch));
+
         /// <summary>
         /// Execute an asynchronous redis operation.
         /// </summary>
@@ -69,6 +73,27 @@ private static async Task<T> ExecuteAsyncInternal<T>(object redisBase, object me
             var processorType = asm.GetType("StackExchange.Redis.ResultProcessor`1").MakeGenericType(genericType);
             var serverType = asm.GetType("StackExchange.Redis.ServerEndPoint");
 
+            Action<object, object, object, object> instrumentedMethod = null;
+
+            instrumentedMethod =
+                MethodBuilder<Action<object, object, object, object>>
+                   .Start(Assembly.GetCallingAssembly(), mdToken, opCode, nameof(BeforeAction))
+                   .WithConcreteTypeName(DiagnosticSource)
+                   .WithParameters(diagnosticSource, actionDescriptor, httpContext, routeData)
+                   .Build();
+
+            try
+            {
+                // call the original method, catching and rethrowing any unhandled exceptions
+                instrumentedMethod?.Invoke(diagnosticSource, actionDescriptor, httpContext, routeData);
+            }
+            catch (Exception ex)
+            {
+                // profiled app will continue working as expected without this method
+                Log.Error($"Exception when calling {methodDef}.", ex);
+                throw;
+            }
+
             var originalMethod = Emit.DynamicMethodBuilder<Func<object, object, object, object, Task<T>>>
                .CreateMethodCallDelegate(
                     thisType,