better dht record class

lib/tools/json_tools.dart

@@ -0,0 +1,30 @@
+// import 'package:fast_immutable_collections/fast_immutable_collections.dart';
+import 'package:veilid/veilid.dart';
+import 'dart:typed_data';
+import 'dart:convert';
+
+extension FromValueDataJsonExt on ValueData {
+  T readJsonData<T>(T Function(Map<String, dynamic>) fromJson) {
+    return fromJson(jsonDecode(utf8.decode(data)));
+  }
+}
+
+Uint8List jsonEncodeBytes(Object? object,
+    {Object? Function(Object?)? toEncodable}) {
+  return Uint8List.fromList(
+      utf8.encode(jsonEncode(object, toEncodable: toEncodable)));
+}
+
+Future<Uint8List> jsonUpdateBytes<T>(T Function(Map<String, dynamic>) fromJson,
+    Uint8List oldBytes, Future<T> Function(T) update) async {
+  T oldObj = fromJson(jsonDecode(utf8.decode(oldBytes)));
+  T newObj = await update(oldObj);
+  return jsonEncodeBytes(newObj);
+}
+
+Future<Uint8List> Function(Uint8List) jsonUpdate<T>(
+    T Function(Map<String, dynamic>) fromJson, Future<T> Function(T) update) {
+  return (Uint8List oldBytes) {
+    return jsonUpdateBytes(fromJson, oldBytes, update);
+  };
+}