Fantom-foundation/go-lachesis

package gossip

import (
    "github.com/Fantom-foundation/go-lachesis/hash"
    "github.com/Fantom-foundation/go-lachesis/inter"
    "github.com/Fantom-foundation/go-lachesis/inter/idx"
)

type PackInfo struct {
    Index       idx.Pack
    Size        uint32
    NumOfEvents uint32
    Heads       hash.Events
}

const (
    maxPackSize      = softResponseLimitSize
    maxPackEventsNum = softLimitItems
)

func (s *Service) packsOnNewEvent(e *inter.Event, epoch idx.Epoch) {
    // due to default values, we don't need to explicitly set values at a start of an epoch
    packIdx := s.store.GetPacksNumOrDefault(epoch)
    packInfo := s.store.GetPackInfoOrDefault(s.engine.GetEpoch(), packIdx)

    s.store.AddToPack(epoch, packIdx, e.Hash())

    packInfo.Index = packIdx
    packInfo.NumOfEvents++
    packInfo.Size += uint32(e.Size())
    if packInfo.NumOfEvents >= maxPackEventsNum || packInfo.Size >= maxPackSize {
        // pin the s.store.GetHeads()
        packInfo.Heads = s.store.GetHeads(epoch)
        s.store.SetPacksNum(epoch, packIdx+1)

        _ = s.feed.newPack.Send(packIdx + 1) // notify about new pack
    }
    s.store.SetPackInfo(epoch, packIdx, packInfo)
}

func (s *Service) packsOnNewEpoch(oldEpoch, newEpoch idx.Epoch) {
    // pin the last pack
    packIdx := s.store.GetPacksNumOrDefault(oldEpoch)
    packInfo := s.store.GetPackInfoOrDefault(s.engine.GetEpoch(), packIdx)

    packInfo.Heads = s.store.GetHeads(oldEpoch)
    s.store.SetPackInfo(oldEpoch, packIdx, packInfo)

    s.store.SetPacksNum(oldEpoch, packIdx+1) // the last pack is always not pinned, so create not pinned one

    _ = s.feed.newPack.Send(packIdx + 1)
}