Rethinking of external assets about event-model HOT 3 OPEN

I sketched out the old and new (with a single event, multiple events would make more use of the slice object)

Here's a suggestion as to how it could be implemented.

• StreamDatum
  • no datum_kwargs
  • no stream_name, instead a pointer to the Descriptor it provides some or all of the data_keys
  • data_keys list to show which data_keys of the Descriptor it provides
  • seq_nums is a slice object showing the Event numbers it corresponds to
  • indexes is a slice object passed to the StreamResource handler so it can hand back data and timestamps
• Event and EventPage
  • external data_keys will be missing from data and timestamps

The Event side of the diagram then becomes optional, if all detectors write external files then there will be no Event documents

@tcaswell @danielballan shall we begin writing this?

from event-model.

Yes, I think so. I'd like to do this in tandem with @DiamondJoseph's NeXus writers and a sketch of our proposed new storage model for Databroker to validate that everything works out the way we expect.

from event-model.

Can delete stream_names from StreamResource too

from event-model.