Retry

You can set up a task and a retry policy so that the task will process and retry automatically expected when it fails.

In Trivial.Tasks namespace of Trivial.dll library.

Linear retry policy

You can create a retry policy to process the specific handler within the specific times with the specific time span between two processing.

var retryPolicy = new LinearRetryPolicy(3, TimeSpan.FromSeconds(10));

// So following task will throw an InvalidOperationException but it will retry 3 times with 10s interval.
var proccessResult = retryPolicy.ProcessAsync(() =>
{
    throw new InvalidOperationException();
}, typeof(InvalidOperationException));

If you want to create a retry policy that the waiting time increases per processing, you can set the 3rd argument in the constructor for the time span of the increment.

Customized retry policy

You can also create a customized retry policy.

var retryPolicy = new CustomizedRetryPolicy(retryRecord =>
{
    // This function need return the time span for waiting for retry; or null, to stop retry.
    return retryRecord.Length < 6 ? TimeSpan.FromSeconds(retryRecord.Length) : null;
});
// This example is as same as following.
// var retryPolicy = new LinearRetryPolicy(5, 0, TimeSpan.FromSeconds(1));

Customized exception handler

Since you may customize some exception handlers instead to set a list of exception type for catching, you can code like below. P.S.: You need use namespace Trivial.Reflection firstly.

// Create an instance.
var exceptionHanlder = new ExceptionHandler();

// Register an exception type to catch without details check.
exceptionHandler.Add<InvalidOperationException>();

// Register a handler for an exception to catch.
// The handler will indicate whether this exception need catch,
// and return the exception if need throw,
// even if the exception returned is not the one in parameter.
exceptionHandler.Add<ArgumentException>(ex =>
{
    return ex.ParamName == "name" ? null : ex;
});

// Usage.
var proccessResult = retryPolicy.ProcessAsync(() =>
{
    // Do something here.
}, exceptionHandler.GetException);

It will catch the exception by these one by one like try-catch.