Report services are not using Blob storage SDK classes anymore.

[agr]

Report services were using Storage SDK classes directly instead of our wrappers around them. To centralize blob storage access code this change makes them use ICloudBlobClient.

Duplicated code that switches between the primary and alternate source for stats was removed from individual services and moved into DI container. A registration of ICloudBlobClient keyed as BindingKeys.FeatureFlaggedStatisticsKey resolves to a blob client that points to the proper storage account. Services are supposed to request Func<ICloudBlobClient> from the DI container that will provide proper client on each individual call.

A SimpleCloudBlobExtensions class was introduced to close the gap between CloudBlockBlobReference class provided by the storage SDK and CloudBlobWrapper in our code (specifically, our wrapper lacks equivalent of DownloadTextAsync).

Additionally, report services did a .ExistAsync() checks before accessing the blob contents, causing unnecessary network round trip. More helpers were added to SimpleCloudBlobExtensions to handle missing blobs gracefully on content retrieval instead, saving one HTTP request on each report content access.

Lastly, CloudDownloadCountService was made async to accommodate for async-only ISimpleCloudBlob.

[skofman1]

[loic-sharma]

Can we make sure that all async method names have an Async suffix? Or would that be a huge change?

Also, please add an await here. See: https://github.com/davidfowl/AspNetCoreDiagnosticScenarios/blob/master/AsyncGuidance.md#prefer-asyncawait-over-directly-returning-task

[agr]

Unfortunately, our NuGetJobCoordinator complains if that Execute method returns a started task, so we have to wrap it in a new Task(), updated the code.

NuGetGallery/src/NuGetGallery/Infrastructure/Jobs/NuGetJobCoordinator.cs

Lines 45 to 60 in be38792

	private static Task CreateWrappingContinuingTask(Task originalTask, Action<Task> continuationTask, TaskContinuationOptions options)
	{
	var continuation = originalTask.ContinueWith(continuationTask, options);
	var wrapper = new Task(() =>
	{
	if (originalTask.Status == TaskStatus.WaitingForActivation || originalTask.Status == TaskStatus.Created)
	{
	originalTask.Start();
	}
	continuation.Wait();
	});
	return wrapper;
	}
	}

(line 53)

[loic-sharma]

This is awesome!! 🥇