Transfer total slots calculation to smesher service

[poszu]

No description provided.

[poszu]

Moving this calculation to the smeshing service might not give the expected benefit. Currently, slots are calculated on the node-service like this:

go-spacemesh/miner/proposal_builder.go

Lines 555 to 575 in 837e7fa

	ballot, err := ballots.FirstInEpoch(pb.db, s.atx, s.epoch)
	if err != nil && !errors.Is(err, sql.ErrNotFound) {
	return fmt.Errorf("get refballot %w", err)
	}
	if errors.Is(err, sql.ErrNotFound) {
	s.beacon = pb.shared.beacon
	s.eligibilities.slots = proposals.MustGetNumEligibleSlots(
	s.atxWeight,
	minweight.Select(lid.GetEpoch(), pb.cfg.minActiveSetWeight),
	pb.shared.active.weight,
	pb.cfg.layerSize,
	pb.cfg.layersPerEpoch,
	)
	} else {
	if ballot.EpochData == nil {
	return fmt.Errorf("atx %d created invalid first ballot", s.atx)
	}
	s.ref = ballot.ID()
	s.beacon = ballot.EpochData.Beacon
	s.eligibilities.slots = ballot.EpochData.EligibilityCount
	}

AFAIR, the calculation might return a different result depending on which node is asked or when it is asked (what view on atxSetWeight it has) . Because the smesher must be consistent about its slots throughout the epoch, it mustn't change its mind after publihing the first ballot.

Thus, to remove the API to calculate the slots I would need to add another one to obtain the first ballot. At this point, the entire effort loses the point because it's trading 1 API call for another...