feat: local cache

pkg/rpccache/common.go

@@ -0,0 +1,20 @@
+package rpccache
+
+func newListMap[V comparable](values []V, err error) (*listMap[V], error) {
+	if err != nil {
+		return nil, err
+	}
+	lm := &listMap[V]{
+		List: values,
+		Map:  make(map[V]struct{}, len(values)),
+	}
+	for _, value := range values {
+		lm.Map[value] = struct{}{}
+	}
+	return lm, nil
+}
+
+type listMap[V comparable] struct {
+	List []V
+	Map  map[V]struct{}
+}