public IRowCursor[] GetRowCursorSet(out IRowCursorConsolidator consolidator, Func <int, bool> predicate, int n, IRandom rand = null)
{
var host = new ConsoleEnvironment().Register("Estimate n threads");
n = DataViewUtils.GetThreadCount(host, n);
if (n <= 1)
{
consolidator = null;
return(new IRowCursor[] { GetRowCursor(predicate, rand) });
}
else
{
var cursors = Source.GetRowCursorSet(out consolidator, i => predicate(i) || predicate(SchemaHelper.NeedColumn(_columnMapping, i)),
n, rand);
for (int i = 0; i < cursors.Length; ++i)
{
cursors[i] = new AddRandomCursor(this, cursors[i]);
}
return(cursors);
}
}
public DataViewRowCursor[] GetRowCursorSet(IEnumerable <DataViewSchema.Column> columnsNeeded, int n, Random rand = null)
{
n = DataViewUtils.GetThreadCount(n);
if (n <= 1)
{
return new DataViewRowCursor[] { GetRowCursor(columnsNeeded, rand) }
}
;
else
{
//var cols = SchemaHelper.ColumnsNeeded(columnsNeeded, Schema, _args.columns);
var cols = SchemaHelper.ColumnsNeeded(columnsNeeded, Source.Schema);
var cursors = Source.GetRowCursorSet(cols, n, rand);
for (int i = 0; i < cursors.Length; ++i)
{
cursors[i] = new AddRandomCursor(this, cursors[i]);
}
return(cursors);
}
}