Call method immediately after object construction in LINQ query
- by Steffen
I've got some objects which implement this interface:
public interface IRow
{
void Fill(DataRow dr);
}
Usually when I select something out of db, I go:
public IEnumerable<IRow> SelectSomeRows
{
DataTable table = GetTableFromDatabase();
foreach (DataRow dr in table.Rows)
{
IRow row = new MySQLRow(); // Disregard the MySQLRow type, it's not important
row.Fill(dr);
yield return row;
}
}
Now with .Net 4, I'd like to use AsParallel, and thus LINQ.
I've done some testing on it, and it speeds up things alot (IRow.Fill uses Reflection, so it's hard on the CPU)
Anyway my problem is, how do I go about creating a LINQ query, which calls Fills as part of the query, so it's properly parallelized?
For testing performance I created a constructor which took the DataRow as argument, however I'd really love to avoid this if somehow possible.
With the constructor in place, it's obviously simple enough:
public IEnumerable<IRow> SelectSomeRowsParallel
{
DataTable table = GetTableFromDatabase();
return from DataRow dr in table.Rows.AsParallel()
select new MySQLRow(dr);
}
However like I said, I'd really love to be able to just stuff my Fill method into the LINQ query, and thus not need the constructor overload.
