| 1 | | | import '../../exceptions/squadron_error.dart'; |
| 2 | | | |
| 3 | | | class Transferables { |
| 4 | | | const Transferables._(); |
| 5 | | | |
| 6 | | 9 | static List<Object>? get(List args) { |
| 7 | | 9 | final objects = _get(args, <Object>{}).toList(); |
| 8 | | 9 | return objects.isEmpty ? null : objects; |
| 9 | | 9 | } |
| 10 | | | |
| 11 | | 9 | static bool _isBaseType(Object? data) => |
| 12 | | 9 | (data == null || data is String || data is num || data is bool); |
| 13 | | | |
| 14 | | | static bool _isListOfBaseType(Object? data) => |
| 15 | | 9 | (data is List<String> || data is List<num> || data is List<bool>); |
| 16 | | | |
| 17 | | 9 | static bool _isSafeForTransfer(Object? data) { |
| 18 | | 9 | if (_isBaseType(data)) return true; |
| 19 | | 0 | if (_isListOfBaseType(data)) return true; |
| 20 | | 9 | if (data is List && data.every(_isSafeForTransfer)) return true; |
| 21 | | 9 | return false; |
| 22 | | 9 | } |
| 23 | | | |
| 24 | | 9 | static bool _isNotSafeForTransfer(Object? data) => !_isSafeForTransfer(data); |
| 25 | | | |
| 26 | | | /// Excludes base type values from [list]. |
| 27 | | 9 | static Iterable<Object> _getObjects(Iterable list, Set<Object> seen) sync* { |
| 28 | | 9 | for (var o in list.where(_isNotSafeForTransfer)) { |
| 29 | | 9 | if (!seen.contains(o)) { |
| 30 | | 9 | seen.add(o); |
| 31 | | 9 | yield o as Object; |
| 32 | | | } |
| 33 | | | } |
| 34 | | 9 | } |
| 35 | | | |
| 36 | | | static void _checkKeys(Map data) { |
| 37 | | 0 | if (!data.keys.every(_isBaseType)) { |
| 38 | | 0 | throw SquadronErrorExt.create( |
| 39 | | | 'Map keys must be strings, numbers or booleans.'); |
| 40 | | | } |
| 41 | | | } |
| 42 | | | |
| 43 | | | /// Yields objects contained in [message]. Used to identify non-base type objects and provide |
| 44 | | | /// them to [Worker.postMessage]. [Worker.postMessage] will clone these objects. The code makes |
| 45 | | | /// no effort to ensure these objects really are transferable. |
| 46 | | 9 | static Iterable<Object> _get(List message, Set<Object> seen) sync* { |
| 47 | | 9 | if (_isSafeForTransfer(message)) return; |
| 48 | | 9 | final toBeInspected = _getObjects(message, seen).toList(); |
| 49 | | | var i = 0; |
| 50 | | 9 | while (i < toBeInspected.length) { |
| 51 | | 9 | final arg = toBeInspected[i++]; |
| 52 | | 9 | if (arg is Map) { |
| 53 | | | _checkKeys(arg); |
| 54 | | 0 | toBeInspected.addAll(_getObjects(arg.values, seen)); |
| 55 | | 9 | } else if (arg is Iterable) { |
| 56 | | 4 | toBeInspected.addAll(_getObjects(arg, seen)); |
| 57 | | | } else { |
| 58 | | 9 | yield arg; |
| 59 | | | } |
| 60 | | | } |
| 61 | | 9 | } |
| 62 | | | } |