A number of new storage features for blobs has been pushed to the cloud in the latest July SDK. Probably the most exciting feature is the ‘Shared Access Signature’ (aka leased blobs). This feature allows you to generate one-time, temporally bound URIs that you can give out to untrusted participants in your application. You can think of it as giving out a ticket to access your blob storage for a period of time with only a certain set of permissions (read, update, etc.). This is a very useful feature that alleviates the need to have an service stand between your user’s data and the shared blob storage to securely intermediate access.
Next, we have the root blob container feature. This allows us to store blob files directly at the root of the service URI (e.g. http://dunnry.blob.core.windows.net/somefile.ext). This is very useful because it allows us to store the necessary crossdomain policy xml files for Silverlight applications and serve XAP files directly from blob storage.
Finally we have the update to the PutBlockList api. With this update, you can now update a single block within a file. If you have a very large blob where only a small part of it changes, this feature would allow you to only replace the blocks where the change occurs instead of having to upload the entire blob over again. Very handy…
For more details, please read the announcement.
Please note: There currently is no SDK support for these new storage features through the local developer fabric.