Unity Interceptor to log the elapsed time of a method.

ProfilingInterceptionBehavior.cs

public class ProfilingInterceptionBehavior : IInterceptionBehavior
{
    [Dependency]
    public ILog Log { get; set; }
    
    public IMethodReturn Invoke(IMethodInvocation input, 
        GetNextInterceptionBehaviorDelegate getNext)
    {
        //This behavior will record the start and stop time
        //of a method and will log the method name and elapsed time.
        //Get the current time.
        var startTime = DateTime.Now;
        
        //Log the start time of the method.
        //This could be ommitted if you just want to see the response times of a method.
        WriteLog(String.Format(
          "Invoking method {0} at {1}",
          input.MethodBase, startTime.ToLongTimeString()));

        // Invoke the next behavior in the chain.
        var result = getNext()(input, getNext);

        //Calculate the elapsed time.
        var endTime = DateTime.Now;
        var timeSpan = endTime - startTime;
        
        
        //The following will log the method name and elapsed time.
        if (result.Exception != null)
        {
            //Method threw an exception.
            WriteLog(String.Format(
              "Method {0} threw exception {1} at {2}.  Elapsed Time: {3} ms",
              input.MethodBase, result.Exception.Message,
              endTime.ToLongTimeString(),
              timeSpan.TotalMilliseconds));
        }
        else
        {
            //Method completed normally.
            WriteLog(String.Format(
              "Method {0} returned {1} at {2}.  Elapsed Time: {3} ms",
              input.MethodBase, result.ReturnValue,
              endTime.ToLongTimeString(),
              timeSpan.TotalMilliseconds));
        }

        return result;
    }

    public IEnumerable<Type> GetRequiredInterfaces()
    {
        return Type.EmptyTypes;
    }

    public bool WillExecute
    {
        get { return true; }
    }

    private void WriteLog(string message)
    {
        if (Log != null)
        {
            Log.DebugFormat("Profiler: {0}", message);
        }
    }

}