/// <summary>
/// Repeatedly executes the specified asynchronous task while it satisfies the current retry policy.
/// </summary>
/// <param name="taskFunc">A function that returns a started task (also known as "hot" task).</param>
/// <param name="cancellationToken">The token used to cancel the retry operation. This token does not cancel the execution of the asynchronous task.</param>
/// <returns>
/// Returns a task that will run to completion if the original task completes successfully (either the
/// first time or after retrying transient failures). If the task fails with a non-transient error or
/// the retry limit is reached, the returned task will transition to a faulted state and the exception must be observed.
/// </returns>
public Task <TResult> ExecuteAsync <TResult>(Func <Task <TResult> > taskFunc, CancellationToken cancellationToken)
{
if (taskFunc == null)
{
throw new ArgumentNullException(nameof(taskFunc));
}
return(new AsyncExecution <TResult>(taskFunc, RetryStrategy.GetShouldRetry(), new Func <Exception, bool>(ErrorDetectionStrategy.IsTransient), new Action <int, Exception, TimeSpan>(OnRetrying), RetryStrategy.FastFirstRetry, cancellationToken).ExecuteAsync());
}
/// <summary>
/// Initializes a new instance of the <see cref="RetryPolicy" /> class with the specified number of retry attempts and parameters defining the progressive delay between retries.
/// </summary>
/// <param name="errorDetectionStrategy">The <see cref="ITransientErrorDetectionStrategy" /> that is responsible for detecting transient conditions.</param>
/// <param name="retryStrategy">The strategy to use for this retry policy.</param>
public RetryPolicy(ITransientErrorDetectionStrategy errorDetectionStrategy, RetryStrategy retryStrategy)
{
Guard.ArgumentNotNull(errorDetectionStrategy, "errorDetectionStrategy");
Guard.ArgumentNotNull(retryStrategy, "retryPolicy");
ErrorDetectionStrategy = errorDetectionStrategy;
if (errorDetectionStrategy == null)
{
throw new InvalidOperationException("The error detection strategy type must implement the ITransientErrorDetectionStrategy interface.");
}
RetryStrategy = retryStrategy;
}
/// <summary>
/// Repetitively executes the specified asynchronous task while it satisfies the current retry policy.
/// </summary>
/// <param name="taskAction">A function that returns a started task (also known as "hot" task).</param>
/// <param name="cancellationToken">The token used to cancel the retry operation. This token does not cancel the execution
/// of the asynchronous task.</param>
/// <returns>
/// Returns a task that will run to completion if the original task completes successfully (either the
/// first time or after retrying transient failures). If the task fails with a non-transient error or
/// the retry limit is reached, the returned task will transition to a faulted state and the exception must be observed.
/// </returns>
public Task RunWithRetryAsync(Func <Task> taskAction, CancellationToken cancellationToken = default)
{
return(taskAction == null
? throw new ArgumentNullException(nameof(taskAction))
: RunWithRetryAsync(
taskAction,
RetryStrategy.GetShouldRetry(),
new Func <Exception, bool>(ErrorDetectionStrategy.IsTransient),
new Action <int, Exception, TimeSpan>(OnRetrying),
RetryStrategy.FastFirstRetry,
cancellationToken));
}
/// <summary>
/// Repetitively executes the specified action while it satisfies the current retry policy.
/// </summary>
/// <typeparam name="TResult">The type of result expected from the executable action.</typeparam>
/// <param name="func">A delegate that represents the executable action that returns the result of type <typeparamref name="TResult" />.</param>
/// <returns>The result from the action.</returns>
public virtual TResult ExecuteAction <TResult>(Func <TResult> func)
{
Guard.ArgumentNotNull(func, "func");
int num = 0;
ShouldRetry shouldRetry = RetryStrategy.GetShouldRetry();
TResult result;
while (true)
{
Exception ex;
TimeSpan zero;
try
{
result = func();
break;
}
catch (RetryLimitExceededException ex2)
{
if (ex2.InnerException != null)
{
throw ex2.InnerException;
}
result = default;
break;
}
catch (Exception ex3)
{
ex = ex3;
if (!ErrorDetectionStrategy.IsTransient(ex) || !shouldRetry(num++, ex, out zero))
{
throw;
}
}
if (zero.TotalMilliseconds < 0.0)
{
zero = TimeSpan.Zero;
}
OnRetrying(num, ex, zero);
if (num > 1 || !RetryStrategy.FastFirstRetry)
{
Task.Delay(zero).Wait();
}
}
return(result);
}
