50 lines
1.2 KiB
Dart
50 lines
1.2 KiB
Dart
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class CacheDecision {
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final bool canUseCached;
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final bool shouldRefreshInBackground;
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final bool mustBlockForNetwork;
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const CacheDecision({
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required this.canUseCached,
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required this.shouldRefreshInBackground,
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required this.mustBlockForNetwork,
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});
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}
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class CachePolicy {
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final Duration softTtl;
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final Duration hardTtl;
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final Duration minRefreshInterval;
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const CachePolicy({
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required this.softTtl,
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required this.hardTtl,
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this.minRefreshInterval = Duration.zero,
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});
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CacheDecision evaluate({required DateTime now, required DateTime fetchedAt}) {
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final age = now.difference(fetchedAt);
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if (age >= hardTtl) {
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return const CacheDecision(
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canUseCached: false,
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shouldRefreshInBackground: false,
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mustBlockForNetwork: true,
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);
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}
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if (age >= softTtl) {
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final shouldRefresh = age >= minRefreshInterval;
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return CacheDecision(
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canUseCached: true,
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shouldRefreshInBackground: shouldRefresh,
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mustBlockForNetwork: false,
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);
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}
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return const CacheDecision(
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canUseCached: true,
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shouldRefreshInBackground: false,
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mustBlockForNetwork: false,
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);
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}
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}
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