syncbase: BeginBatch() bugfix and restartability TODOs
This CL addresses a few issues uncovered by jlodhia@.
- Makes it so that Database.BeginBatch() fails gracefully if
the database does not exist (and adds a test).
- Restores the general mechanism for tracking existence in server's
app/db structs, to prevent this problem from recurring elsewhere.
- Adds TODOs for supporting restartability by making service.apps
and app.dbs act like lazily-populated caches.
Change-Id: I788d6681c322cd8bc43472b4faa4663235d240c2
4 files changed
