fix(store): make heightIndexer.IndexTo as a func (#182)

Author: cristaloleg

store/height_indexer.go

@@ -44,15 +44,3 @@ func (hi *heightIndexer[H]) HashByHeight(ctx context.Context, h uint64) (header.
 	hi.cache.Add(h, header.Hash(val))
 	return val, nil
 }
-
-// IndexTo saves mapping between header Height and Hash to the given batch.
-func (hi *heightIndexer[H]) IndexTo(ctx context.Context, batch datastore.Batch, headers ...H) error {
-	for _, h := range headers {
-		err := batch.Put(ctx, heightKey(h.Height()), h.Hash())
-		if err != nil {
-			return err
-		}
-	}
-
-	return nil
-}

store/store.go

@@ -476,8 +476,7 @@ func (s *Store[H]) flush(ctx context.Context, headers ...H) error {
 	}
 
 	// write height indexes for headers as well
-	err = s.heightIndex.IndexTo(ctx, batch, headers...)
-	if err != nil {
+	if err := indexTo(ctx, batch, headers...); err != nil {
 		return err
 	}
 
@@ -516,3 +515,14 @@ func (s *Store[H]) get(ctx context.Context, hash header.Hash) ([]byte, error) {
 	s.metrics.readSingle(ctx, time.Since(startTime), false)
 	return data, nil
 }
+
+// indexTo saves mapping between header Height and Hash to the given batch.
+func indexTo[H header.Header[H]](ctx context.Context, batch datastore.Batch, headers ...H) error {
+	for _, h := range headers {
+		err := batch.Put(ctx, heightKey(h.Height()), h.Hash())
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}