50 lines
1.1 KiB
Dart
50 lines
1.1 KiB
Dart
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import '../../../users/data/models/user_response.dart';
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class SettingsUserCache {
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UserResponse? _cachedUser;
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Future<UserResponse>? _inflight;
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int _generation = 0;
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UserResponse? get cachedUser => _cachedUser;
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Future<UserResponse> getOrLoad(Future<UserResponse> Function() loader) {
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final cached = _cachedUser;
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if (cached != null) {
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return Future<UserResponse>.value(cached);
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}
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final inflight = _inflight;
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if (inflight != null) {
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return inflight;
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}
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final generation = _generation;
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late final Future<UserResponse> request;
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request = loader()
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.then((user) {
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if (generation == _generation) {
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_cachedUser = user;
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}
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return user;
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})
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.whenComplete(() {
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if (identical(_inflight, request)) {
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_inflight = null;
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}
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});
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_inflight = request;
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return request;
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}
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void set(UserResponse user) {
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_cachedUser = user;
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}
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void invalidate() {
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_generation += 1;
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_cachedUser = null;
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_inflight = null;
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}
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}
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