Files

53 lines
1.5 KiB
Go

package lmdb
import (
"fmt"
"fiatjaf.com/nostr"
"github.com/PowerDNS/lmdb-go/lmdb"
)
func (b *LMDBBackend) ReplaceEvent(evt nostr.Event) (deleted []nostr.Event, err error) {
err = b.lmdbEnv.Update(func(txn *lmdb.Txn) error {
// check if we already have this id
_, existsErr := txn.Get(b.indexId, evt.ID[0:8])
if existsErr == nil {
return nil
}
if operr, ok := existsErr.(*lmdb.OpError); !ok || operr.Errno != lmdb.NotFound {
return existsErr
}
filter := nostr.Filter{Kinds: []nostr.Kind{evt.Kind}, Authors: []nostr.PubKey{evt.PubKey}}
if evt.Kind.IsAddressable() {
// when addressable, add the "d" tag to the filter
filter.Tags = nostr.TagMap{"d": []string{evt.Tags.GetD()}}
}
// now we fetch the past events, whatever they are, delete them and then save the new
shouldStore := true
if qerr := b.query(txn, filter, 10 /* could be just 1 */, func(previous nostr.Event) bool {
if nostr.IsOlder(previous, evt) {
if qerr := b.delete(txn, previous.ID); qerr != nil {
qerr = fmt.Errorf("failed to delete event %s for replacing: %w", previous.ID, qerr)
return false
}
deleted = append(deleted, previous)
} else {
// there is a newer event already stored, so we won't store this
shouldStore = false
}
return true
}); qerr != nil {
return fmt.Errorf("failed to query past events with %s: %w", filter, qerr)
}
if shouldStore {
return b.save(txn, evt)
}
return nil
})
return deleted, err
}