/// <summary>
/// Retry asynchronous function repeatedly. See <see cref="MultiTryOptions{T}"/> for specific options
/// </summary>
/// <typeparam name="T">Return type</typeparam>
/// <param name="function">Async function to execute. Required</param>
/// <param name="options">Retry options. Can be null, see <see cref="MultiTryOptions{T}"/> for defaults</param>
/// <returns>function result or value specified in <see cref="MultiTryOptions{T}.OnFinalFailure"/></returns>
public static async Task <T> TryAsync <T>(Func <Task <T> > function, MultiTryOptions <T> options = null)
{
options = Validate(function, options);
var i = 0;
Exception lastException;
do
{
try
{
return(await function.Invoke());
}
catch (Exception ex) when(options.ExceptionFilter(ex))
{
lastException = ex;
if (options.OnException?.Invoke(ex, i) == false)
{
break;
}
}
if (options.Delay > 0)
{
await Task.Delay(options.Delay);
}
i++;
} while (i < options.TryCount);
return(options.OnFinalFailure.Invoke(lastException));
}
private static MultiTryOptions <T> Validate <T>(Delegate function, MultiTryOptions <T> options)
{
if (function == null)
{
throw new ArgumentNullException(nameof(function), "MultiTry: function must be set!");
}
if (options == null)
{
options = MultiTryOptions <T> .Default;
}
options.Validate();
return(options);
}
/// <summary>
/// Retry action repeatedly
/// <param name="action">Action to execute</param>
/// <param name="options">Retry options. Can be null, see <see cref="MultiTryOptions"/> for defaults</param>
/// </summary>
public static void Try(Action action, MultiTryOptions options = null)
{
if (action == null)
{
throw new ArgumentNullException(nameof(action), "MultiTry: action must be set!");
}
if (options == null)
{
options = MultiTryOptions.Default;
}
options.Validate();
var i = 0;
Exception lastException;
do
{
try
{
action.Invoke();
return;
}
catch (Exception ex) when(options.ExceptionFilter(ex))
{
lastException = ex;
if (options.OnException?.Invoke(ex, i) == false)
{
break;
}
}
if (options.Delay > 0)
{
Thread.Sleep(options.Delay);
}
i++;
} while (i < options.TryCount);
options.OnFinalFailure?.Invoke(lastException);
}