TimelineRecorder / TimelineSegment

[sobri909]

This is an issue to track development on the new managers / stores architecture for the next major release.

db -> store -> recorder / segment / processor

public TimelineRecorder (new)

TimelineRecorder will take over the jobs of a) communicating with LocomotionManager, and b) creating new timeline items.

The Recorder does not do any Item processing. It records new Samples and new TimelineItems, using the existing logic for whether to continue the current Item or create a new Item (ie on stationary/moving state changes, and activityType changes).

This division of labour keeps the Recorder simple and focused, and makes it easier to separate the Item processing loop from the recording loop. Which should hopefully allow for more battery efficient recording, by way of delaying Item processing until a point in time where it becomes necessary (eg sleep mode is about to start; some UI wants to show processed items to the user; etc).

public TimelineSegment (new)

TimelineSegment adds functionality for fetching of TimelineItems within specified date ranges. It will also internally manage the processing of these Items (by making use of TimelineProcessor) so that the resulting Items set is coherent and human presentable (as compared to the raw unprocessed Items produced by Recorder).

public TimelineProcessor (new)

TimelineProcessor takes over the internal job of processing (merging, edge cleansing, safe deleting, etc) sequential Items.

TimelineManager

TimelineManager will be removed. The new classes take over all of its responsibilities, so it will be made redundant.

Misc todos

• Make these classes final, no subclassing (only stores should be custom)
• Only one Recorder per Store
• Can have multiple overlapping Segments
• Segments are created by giving a date range or SQL query
• Should probably move Arc App's edge healing to LocoKit
• Should probably move Arc App's data gap insertion to LocoKit
• Fix the mystery broken item edges that aren't broken at heal time
• Persistent store needs to add a data gap at startup

Todos for the plain (non persistent) TimelineManager

Non persistent stores are no longer supported 😞

• Need a replacement for finalisedTimelineItem
• ~Non persistent store needs to know which items to retain for active item processing~~

Testing todos

• Stress test in the Demo App
• Road test in a public Arc App release

Docs todos

• Write the API docs
• Write up some example code snippets