private async Task <IState> PerformJob(BackgroundProcessContext context, IStorageConnection connection, string jobId)
{
try
{
var jobData = connection.GetJobData(jobId);
if (jobData == null)
{
// Job expired just after moving to a processing state. This is an
// unreal scenario, but shit happens. Returning null instead of throwing
// an exception and rescuing from en-queueing a poisoned jobId back
// to a queue.
return(null);
}
jobData.EnsureLoaded();
var backgroundJob = new BackgroundJob(jobId, jobData.Job, jobData.CreatedAt);
var jobToken = new ServerJobCancellationToken(connection, jobId, context.ServerId, _workerId, context.CancellationToken);
var performContext = new PerformContext(connection, backgroundJob, jobToken);
var latency = (DateTime.UtcNow - jobData.CreatedAt).TotalMilliseconds;
var duration = Stopwatch.StartNew();
var result = await _performer.PerformAsync(performContext).ConfigureAwait(false);
duration.Stop();
// SHOULD BE: return new SucceededState(result, (long)latency, duration.ElapsedMilliseconds);
return(CreateSucceededState(result, (long)latency, duration.ElapsedMilliseconds));
}
catch (JobAbortedException)
{
// Background job performance was aborted due to a
// state change, so it's idenfifier should be removed
// from a queue.
return(null);
}
catch (JobPerformanceException ex)
{
return(new FailedState(ex.InnerException)
{
Reason = ex.Message
});
}
catch (Exception ex)
{
if (ex is OperationCanceledException && context.IsShutdownRequested)
{
throw;
}
return(new FailedState(ex)
{
Reason = "An exception occurred during processing of a background job."
});
}
}
private Task PerformJobAsync()
{
const TaskContinuationOptions options = TaskContinuationOptions.NotOnCanceled | TaskContinuationOptions.ExecuteSynchronously;
try
{
return(_innerPerformer.PerformAsync(_context).ContinueWith(FillPerformedContext, this, options));
}
catch (Exception ex)
{
// fill performedContext with exception if failed to create task at all
_performedContext = new PerformedContext(_context, null, false, ex);
return(Task.FromResult(0));
}
}