vector-im-hydrogen-web/doc/sync-updates.md

persistance vs model update of a room

persist first, return update object, update model with update object

update model first, return update object, persist with update object

• not all models exist at all times (timeline only when room is "open"), so model to create timeline update object might not exist for persistence need

persist, update, each only based on sync data (independent of each other)

• possible inconsistency between syncing and loading from storage as they are different code paths

• storage code remains very simple and focussed

updating model and persisting in one go

• if updating model needs to do anything async, it needs to postpone it or the txn will be closed

persist first, read from storage to update model

• guaranteed consistency between what is on screen and in storage

• slower as we need to reread what was just synced every time (big accounts with frequent updates)