CloudServices/Sync/FxSync/StoreRedesign: Difference between revisions

Reduce to two classes: ''Store'' and ''Engine''. ''Store''s are both sinks and sources of records; ''Engine''s exist (from one perspective, at least) to reify the relationship between two Stores (including tracking <tt>lastSync</tt>), which in practice means connecting a pair of stores as source then sink in turn.

Stores are entirely responsible for providing a timestamp- and record-centric API over a source of data. This interface abstracts the tracking of changed items and application and retrieval of records, and is uniform across both remote and local storage. For example, we would build a ''FxBookmarkStore'' layer above Places, a ''ServerBookmarkStore'' layer in front of the v5/v1.1 Sync API, and connect the two with a simple Engine. Both Store implementations would implement ''exactly the same interface'', which would allow us to trivially implement:

Furthermore, ''middleware'' (classes that implement the Store interface and wrap another Store) can be used to implement:

* Storage item translation: e.g., define Stores in terms of deltas, but maintain storage version compatibility by translation into full objects.