bring in khatru and eventstore.

eventstore/lmdb/delete.go

@@ -0,0 +1,43 @@
+package lmdb
+
+import (
+	"context"
+	"encoding/hex"
+	"fmt"
+
+	"github.com/PowerDNS/lmdb-go/lmdb"
+	"github.com/nbd-wtf/go-nostr"
+)
+
+func (b *LMDBBackend) DeleteEvent(ctx context.Context, evt *nostr.Event) error {
+	return b.lmdbEnv.Update(func(txn *lmdb.Txn) error {
+		return b.delete(txn, evt)
+	})
+}
+
+func (b *LMDBBackend) delete(txn *lmdb.Txn, evt *nostr.Event) error {
+	idPrefix8, _ := hex.DecodeString(evt.ID[0 : 8*2])
+	idx, err := txn.Get(b.indexId, idPrefix8)
+	if lmdb.IsNotFound(err) {
+		// we already do not have this
+		return nil
+	}
+	if err != nil {
+		return fmt.Errorf("failed to get current idx for deleting %x: %w", evt.ID[0:8*2], err)
+	}
+
+	// calculate all index keys we have for this event and delete them
+	for k := range b.getIndexKeysForEvent(evt) {
+		err := txn.Del(k.dbi, k.key, idx)
+		if err != nil {
+			return fmt.Errorf("failed to delete index entry %s for %x: %w", b.keyName(k), evt.ID[0:8*2], err)
+		}
+	}
+
+	// delete the raw event
+	if err := txn.Del(b.rawEventStore, idx, nil); err != nil {
+		return fmt.Errorf("failed to delete raw event %x (idx %x): %w", evt.ID[0:8*2], idx, err)
+	}
+
+	return nil
+}