scan method
Return all rows visible to ctx (snapshot isolation).
Implementation
List<Map<String, dynamic>> scan(TxnContext ctx) {
final result = <Map<String, dynamic>>[];
for (final chain in _chains.values) {
final v = chain.visibleVersion(ctx);
if (v != null) {
result.add(Map<String, dynamic>.from(v.values));
}
}
return result;
}