Fantom-foundation/go-lachesis

package gossip

import (
    "github.com/ethereum/go-ethereum/rlp"

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

// DelLastHeader deletes record about last header from a validator
func (s *Store) DelLastHeader(epoch idx.Epoch, creator idx.StakerID) {
    key := append(epoch.Bytes(), creator.Bytes()...)

    err := s.table.LastEpochHeaders.Delete(key)
    if err != nil {
        s.Log.Crit("Failed to erase LastHeader", "err", err)
    }
}

// DelLastHeaders deletes all the records about last headers
func (s *Store) DelLastHeaders(epoch idx.Epoch) {
    it := s.table.LastEpochHeaders.NewIterator(epoch.Bytes(), nil)
    defer it.Release()
    s.dropTable(it, s.table.LastEpochHeaders)
}

// AddLastHeader adds/updates a records about last header from a validator
func (s *Store) AddLastHeader(epoch idx.Epoch, header *inter.EventHeaderData) {
    key := append(epoch.Bytes(), header.Creator.Bytes()...)

    s.set(s.table.LastEpochHeaders, key, header)
}

// GetLastHeaders retrieves all the records about last headers from validators
func (s *Store) GetLastHeaders(epoch idx.Epoch) inter.HeadersByCreator {
    hh := make(inter.HeadersByCreator)

    it := s.table.LastEpochHeaders.NewIterator(epoch.Bytes(), nil)
    defer it.Release()
    for it.Next() {
        creator := it.Key()[4:]
        header := &inter.EventHeaderData{}
        err := rlp.DecodeBytes(it.Value(), header)
        if err != nil {
            s.Log.Crit("Failed to decode rlp", "err", err)
        }
        hh[idx.BytesToStakerID(creator)] = header
    }

    return hh
}