retry.cs

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Reflection;
using System.ServiceModel;
using log4net;

namespace Bobby.Chopra
{
    static class SomeService
    {
        private static readonly ILog Logger = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        private static ISomeService Svc
        {
            get
            {
                lock (sync)
                    if (_svc == null)
                        _svc = new ChannelFactory<ISomeService>("*").CreateChannel();
                return _svc;
            }
        }

        static readonly object sync = new object();
        static ISomeService _svc;

        internal static T Retry<T>(Func<T> func, string msg, bool throwException = false)
        {
            T val = default(T);
            var noOfRetries = int.Parse(ConfigurationManager.AppSettings["NoOfRetriesForNtfService"]);
            var success = false;

            for (var tries = 0; tries < noOfRetries && !success; tries++)
            {
                System.Threading.Thread.Sleep(tries * 1000);
                try
                {
                    val = func();
                    success = true;
                }
                catch (Exception ex)
                {
                    Logger.WarnFormat("No Of Tries: {0} \r\nMessage:{1} \r\nException:{2}", tries, msg, ex);
                }
            }

            if (!success && throwException)
            {
                Logger.Error("Could not get " + msg);
                throw new Exception("Could not get " + msg);
            }

            return val;
        }

        public static double TotalReturn(string ticker, DateTime startDate, DateTime endDate)
        {
            var msg = String.Format("Total Return for ticker:{0}, start:{1}, end:{2}", ticker, startDate, endDate);
            return Retry(() => _TotalReturn(ticker, startDate, endDate), msg, true);
        }

        private static double _TotalReturn(string ticker, DateTime startDate, DateTime endDate)
        {
            return var s = Svc.GetData( ... );
        }


        public static double? MethodB(string ticker, DateTime date)
        {
            var msg = String.Format("MethodB for ticker:{0}, date:{1}", ticker, date);
            return Retry(() => _MethodB(ticker, date), msg);
        }

        private static double? _MethodB(string ticker, DateTime date)
        {
            var s = Svc.GetData( ... );

            return string.IsNullOrWhiteSpace(s) ? null : new double?(double.Parse(s));
        }
    }
}