Fantom-foundation/go-lachesis

package gossip

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

func (s *Store) DelHead(epoch idx.Epoch, id hash.Event) {
    es := s.getEpochStore(epoch)
    if es == nil {
        return
    }

    key := id.Bytes()

    if err := es.Heads.Delete(key); err != nil {
        s.Log.Crit("Failed to delete key", "err", err)
    }
}

func (s *Store) AddHead(epoch idx.Epoch, id hash.Event) {
    es := s.getEpochStore(epoch)
    if es == nil {
        return
    }

    key := id.Bytes()

    if err := es.Heads.Put(key, []byte{}); err != nil {
        s.Log.Crit("Failed to put key-value", "err", err)
    }
}

func (s *Store) IsHead(epoch idx.Epoch, id hash.Event) bool {
    es := s.getEpochStore(epoch)
    if es == nil {
        return false
    }

    key := id.Bytes()

    ok, err := es.Heads.Has(key)
    if err != nil {
        s.Log.Crit("Failed to get key", "err", err)
    }
    return ok
}

// GetHeads returns IDs of all the epoch events with no descendants
func (s *Store) GetHeads(epoch idx.Epoch) hash.Events {
    es := s.getEpochStore(epoch)
    if es == nil {
        return nil
    }

    res := make(hash.Events, 0, 100)

    it := es.Heads.NewIterator(nil, nil)
    defer it.Release()
    for it.Next() {
        res.Add(hash.BytesToEvent(it.Key()))
    }
    if it.Error() != nil {
        s.Log.Crit("Failed to iterate keys", "err", it.Error())
    }

    return res
}