The revisionId read-only property of the DataStore interface returns the current data store's current revision ID. This ID can be tracked, allowing you to synchronize apps using the data store to this point in its history.
The sync() method of the DataStore interface opens a cursor that allows you to step through any changes that have taken place in the data store going back to a particular revision ID, and run code in response to different types of change.
The available() method is used to check whether the storage area is available; this is an asynchronous operation that returns a DOMRequest object that will receive a callback when the operation is complete.
The IDBEnvironment interface of the IndexedDB API contains the indexedDB property, which provides access to IndexedDB functionality. It is the top level IndexedDB interface implemented by the window and Worker objects.