Cancellation

Every method that contacts storage takes an optional CancellationToken as its last parameter, so you can name it and leave out the optional parameters before it. A canceled operation throws OperationCanceledException; it never returns null, an empty list or a result for work it didn't finish.

using var timeout = new CancellationTokenSource(TimeSpan.FromMinutes(5));
ResourceInfo stored = await container.UploadAsync("backup.zip", file, cancellationToken: timeout.Token);

4.0 In 3.1, the methods from before 3.1 take a token only in an overload that requires every parameter before it, so pass null for those you don't need: UploadAsync("backup.zip", file, null, timeout.Token).

• A canceled upload stores nothing. Once the new version is stored, though, the upload has succeeded, and the token no longer applies. Pruning older versions then runs to completion (see Versioning).
• DownloadStreamingAsync's token covers finding the resource. To cancel reading the content, pass a token to the stream's ReadAsync or CopyToAsync. DownloadContentAsync does that for you.
• Deleting a container can stop partway, between whole versions; see Containers.