Files
nostrlib/eventstore/lmdb/replace.go

56 lines
1.5 KiB
Go

package lmdb
import (
"fmt"
"iter"
"fiatjaf.com/nostr"
"fiatjaf.com/nostr/eventstore/internal"
"github.com/PowerDNS/lmdb-go/lmdb"
)
func (b *LMDBBackend) ReplaceEvent(evt nostr.Event) error {
return 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
var err error
var results iter.Seq[nostr.Event] = func(yield func(nostr.Event) bool) {
err = b.query(txn, filter, 10 /* in theory limit could be just 1 and this should work */, yield)
}
if err != nil {
return fmt.Errorf("failed to query past events with %s: %w", filter, err)
}
shouldStore := true
for previous := range results {
if internal.IsOlder(previous, evt) {
if err := b.delete(txn, previous.ID); err != nil {
return fmt.Errorf("failed to delete event %s for replacing: %w", previous.ID, err)
}
} else {
// there is a newer event already stored, so we won't store this
shouldStore = false
}
}
if shouldStore {
return b.save(txn, evt)
}
return nil
})
}