/// <summary>
/// Retry a task composition using the specified retry policy
/// </summary>
/// <param name="composer">The task composer</param>
/// <param name="interval">The interval between each repetition</param>
/// <param name="callback">The task composition callback</param>
/// <param name="repeatCancellationToken">A cancellation token for the repeat-portion of the task composer</param>
/// <returns>The original task composer</returns>
public static Composer Repeat(this Composer composer, TimeSpan interval, Action <Composer> callback,
CancellationToken repeatCancellationToken = default(CancellationToken))
{
if (interval < TimeSpan.Zero)
{
throw new ArgumentOutOfRangeException("interval",
"The interval must be non-negative, and it must be less than or equal to Int32.MaxValue.");
}
composer.ComposeTask(taskComposer => Attempt(taskComposer, interval, callback, repeatCancellationToken));
return(composer);
}
/// <summary>
/// Retry a task composition using the specified retry policy
/// </summary>
/// <param name="composer">The task composer</param>
/// <param name="millisecondsInterval"></param>
/// <param name="callback">The task composition callback</param>
/// <param name="repeatCancellationToken"></param>
/// <returns>The original task composer</returns>
public static Composer Repeat(this Composer composer, int millisecondsInterval, Action <Composer> callback,
CancellationToken repeatCancellationToken)
{
if (millisecondsInterval < 0)
{
throw new ArgumentOutOfRangeException("millisecondsInterval",
"The interval must be non-negative, and it must be less than or equal to Int32.MaxValue.");
}
composer.ComposeTask(
taskComposer => Attempt(taskComposer, TimeSpan.FromMilliseconds(millisecondsInterval), callback, repeatCancellationToken));
return(composer);
}
static void Attempt(Composer composer, TimeSpan interval, Action <Composer> callback, CancellationToken repeatCancellationToken)
{
composer.ComposeTask(callback);
composer.ExecuteAsync(token =>
{
if (repeatCancellationToken.IsCancellationRequested)
{
return(TaskUtil.Completed());
}
return(ComposerFactory.Compose(x =>
{
x.Delay(interval);
Attempt(x, interval, callback, repeatCancellationToken);
}, token));
}, ExecuteOptions.RunSynchronously);
}
static void Attempt <T>(Composer <T> composer, IRetryContext retryContext, Action <Composer <T> > callback)
{
composer.ComposeTask(callback);
composer.Compensate(compensation =>
{
TimeSpan delay;
if (!retryContext.CanRetry(compensation.Exception, out delay))
{
return(compensation.Throw());
}
return(compensation.ComposeTask(x =>
{
x.Delay(delay);
Attempt(x, retryContext, callback);
}));
});
}
/// <summary>
/// Retry a task composition using the specified retry policy
/// </summary>
/// <typeparam name="T">The composer payload type</typeparam>
/// <param name="composer">The task composer</param>
/// <param name="retryPolicy">The retry policy</param>
/// <param name="callback">The task composition callback</param>
/// <returns>The original task composer</returns>
public static Composer <T> Retry <T>(this Composer <T> composer, IRetryPolicy retryPolicy, Action <Composer <T> > callback)
{
IRetryContext retryContext = null;
composer.ComposeTask(taskComposer =>
{
retryContext = retryPolicy.GetRetryContext();
Attempt(taskComposer, retryContext, callback);
});
composer.Finally((_, status) =>
{
if (retryContext != null)
{
retryContext.Complete(status);
}
});
return(composer);
}
public void Compose <TPayload>(Composer <Payload <TPayload> > composer, Carrier <Tuple <TPayload, T> > next)
{
composer.ComposeTask(p => composer.Payload.MergeRight(new T()), next.Compose);
}
public static Composer <Payload <T> > ComposeCarrier <T, TPayload>(this Composer <Payload <T> > composer,
Carrier <Tuple <T, TPayload> > next,
Func <Payload <T>, Payload <Tuple <T, TPayload> > > payload)
{
return(composer.ComposeTask(payload, next.Compose));
}
static void Attempt(Composer composer, TimeSpan interval, Action<Composer> callback, CancellationToken repeatCancellationToken)
{
composer.ComposeTask(callback);
composer.ExecuteAsync(token =>
{
if (repeatCancellationToken.IsCancellationRequested)
return TaskUtil.Completed();
return ComposerFactory.Compose(x =>
{
x.Delay(interval);
Attempt(x, interval, callback, repeatCancellationToken);
}, token);
}, ExecuteOptions.RunSynchronously);
}
