read method
Reads string value associated with key from disk.
Implementation
@override
Future<String?> read(String key) async {
await _ensureLoaded();
if (_memoryCache.containsKey(key)) {
return _memoryCache[key];
}
final file = _getFile(key);
if (file.existsSync()) {
final content = await file.readAsString();
_memoryCache[key] = content;
return content;
}
return null;
}