gistfile1.cs

/// Runs the given delegate up to N times before throwing an exception, 
/// if the thrown exception matches a given criteria (retryCondition).
/// </summary>
/// <typeparam name="T">The return type of the delegate.</typeparam>
/// <param name="numberOfRetries">The number of retries.</param>
/// <param name="operation">The delegate to be executed.</param>
/// <param name="retryCondition">A predicate that when evaluated indicates whether the action should be retried.</param>
/// <param name="onRetryAction">An action to be executed before executing the retry.</param>
/// <param name="onErrorAction">An action to be executed before the last chance of the exception is thrown.</param>
/// <returns>The result of the operation.</returns>
public T Run<T>(int numberOfRetries, Func<TableStore, T> operation, Predicate<Exception> retryCondition, Action<Exception> onRetryAction, Action<Exception> onErrorAction)
{
   int counter = 0;

   if (retryCondition == null)
       throw new InvalidOperationException("You cannot run without a Retry Condition Predicate");

   if (operation == null)
       throw new InvalidOperationException("Operation delegate cannot be null");

   var result = default(T);

   while (counter < numberOfRetries)
   {
       try
       {
           result = operation.Invoke(this.store);
           break;
       }
       catch (Exception e)
       {
           counter++;

           if (!retryCondition.Invoke(e) || counter == numberOfRetries)
           {
               if (onErrorAction != null)
                   onErrorAction.Invoke(e);

               throw;
           }

           if (onRetryAction != null)
               onRetryAction.Invoke(e);
       }
   }

   return result;
}