/// <summary>
/// See common summary for RetryHelper
/// </summary>
/// <typeparam name="TResult">The type of return value of <paramref name="func"/></typeparam>
/// <param name="func">The Func<out TResult> delegate to be executed until success</param>
/// <param name="result">The return value from the execution of <paramref name="func"/></param>
/// <param name="preamble"> The delegate to be executed in-between retries. </param>
/// <param name="ignoredExceptions">List if exception types against which resilience is desired</param>
/// <param name="retries">Number of times to try executing the given method before giving up. Default is 3</param>
/// <param name="throwOnFailure">Indicates whether the method should throw RetriesExhaustedException, or not</param>
/// <returns>
/// True upon successful execution of the method, otherwise False. If <paramref name="throwOnFailure"/> is True, then the method will never return False
/// </returns>
internal static bool TryExecuteFunction <TResult>(
Func <TResult> func,
out TResult result,
RetryPreamble preamble,
List <Type> ignoredExceptions,
int retries = 3,
bool throwOnFailure = false)
{
ValidateExceptionTypeList(ignoredExceptions);
result = default(TResult);
int retryCount = retries;
bool success = false;
bool retryPreambleSucceeded = true;
do
{
try
{
if (func != null)
{
result = func.Invoke();
}
success = true;
break;
}
catch (Exception e) when(MatchException(e, ignoredExceptions))
{
}
retryCount--;
if (retryCount > 0)
{
retryPreambleSucceeded = preamble();
}
}while ((retryCount > 0) && retryPreambleSucceeded);
if (!success && throwOnFailure)
{
throw new RetriesExhaustedException();
}
return(success);
}
/// <summary>
/// See common summary for RetryHelper
/// </summary>
/// <param name="action">The Action delegate to be executed until success</param>
/// <param name="preamble">
/// The delegate to be executed in-between retries.
/// </param>
/// <param name="ignoredExceptions">List of exception types against which resilience is desired</param>
/// <param name="retries">Number of times to try executing the given method before giving up. Default is 3</param>
/// <param name="throwOnFailure">Indicates whether the method should throw RetriesExhaustedException, or not</param>
/// <returns>
/// True upon successful execution of the method, otherwise False. If <paramref name="throwOnFailure"/> is True, then the method will never return False
/// </returns>
internal static bool TryCallAction(
Action action,
RetryPreamble preamble,
List <Type> ignoredExceptions,
int retries = 3,
bool throwOnFailure = false)
{
ValidateExceptionTypeList(ignoredExceptions);
int retryCount = retries;
bool success = false;
bool retryPreambleSucceeded = true;
do
{
try
{
action?.Invoke();
success = true;
break;
}
catch (Exception e) when(MatchException(e, ignoredExceptions))
{
// do nothing here
// the exception filter does it all
}
retryCount--;
if (retryCount > 0)
{
retryPreambleSucceeded = preamble();
}
}while ((retryCount > 0) && retryPreambleSucceeded);
if (!success && throwOnFailure)
{
throw new RetriesExhaustedException();
}
return(success);
}