getSize method
Size of this store's on-disk footprint, in KB. Sums the lengths
of every file under storagePath whose name starts with the
box name (Hive writes <boxName>.hive and <boxName>.lock).
The previous impl summed the WHOLE storagePath directory,
which double-counts whenever multiple boxes share a directory
(which they do on the secondary).
Implementation
int getSize() {
final dir = Directory(storagePath);
if (!dir.existsSync()) return 0;
var bytes = 0;
for (final entity in dir.listSync()) {
if (entity is! File) continue;
final name = entity.uri.pathSegments.last;
if (!name.startsWith('$_boxName.')) continue;
bytes += entity.lengthSync();
}
return bytes ~/ 1024;
}