Optimize scanning transactions & other contract events

[johnsmith-gooddollar]

• [ ] when user logs out and login it will rescan the whole contracts events, from the first block
  • [x] we usually store the block the user signed up at, we should make sure we scan only from that block
  • [x] for users that we dont have the number of block they signed up at, we should set it to the first event block number we have for them
  • [ ] perform the rescan only when user app goes to background?

[roma-hladilka]

@sirpy now last block is stored in user storage and updates on every poll. Do we need some additional changes?

[sirpy]

@roma-hladilka no. I believe there's a bug that the TX scanning starts before we sync the user properties from the database so we need to verify we await for the userStorage init before we trigger the scanning

[alt-a1r]

@sirpy Regarding the previous comment, a check has now been added to wait for user properties to be initialized before the initTransferEvents action.

Regarding the third point, now the rescan occurs when the dashboard component is mounted, perhaps it makes sense to leave it in this way, since we need an update every time the dashboard is mounted?

[johnsmith-gooddollar]

@sirpy the comment above is about pt3. "perform the rescan only when user app goes to background"

Could you please describe in details what did you meant here ? What's the idea and goals of this change ? How it should actually working?

[sirpy]

the idea is to to reset or move backwards the lastBlock variable so blocks will be rescanned in case some block was missed, but I dont think it is necessary at the moment.