tree e3fb6b534362bffa726d4a2214754b86513c0a42
parent 105ae053928aa2388ea3ff0139ce2ef441d3513e
author Patrick Hiesel <hiesel@google.com> 1620654260 +0200
committer Patrick Hiesel <hiesel@google.com> 1621960664 +0200

FieldDef: Implement generic backfilling logic

The change index has special behavior for recovering field values
from the index. This is used to serve dashboards and change queries
fast and without looking up data in NoteDb or the ChangeNotesCache.

Until now, each index implementation has implemented this backfilling
on its own for all fields. This change is generalizing the logic
to reduce boiler-plate.

Each index implementation now only has to implement an interface that
converts from its specific types to the types defined by FieldDef
(String, Integer, Long, byte[], Timestamp).

This commit adds backfilling logic for modified lines in ChangeData.

Change-Id: I301bc13c6ab5d8f061aeac6a0aaa09ebdf9e9640