public Cursor(StatefulFilterTransform <TSrc, TDst, TState> parent, IRowCursor <TSrc> input, Func <int, bool> predicate)
: base(parent.Host)
{
Ch.AssertValue(input);
Ch.AssertValue(predicate);
_parent = parent;
_input = input;
_src = new TSrc();
_dst = new TDst();
_state = new TState();
CursorChannelAttribute.TrySetCursorChannel(_parent.Host, _src, Ch);
CursorChannelAttribute.TrySetCursorChannel(_parent.Host, _dst, Ch);
CursorChannelAttribute.TrySetCursorChannel(_parent.Host, _state, Ch);
if (parent._initStateAction != null)
{
parent._initStateAction(_state);
}
var appendedDataView = new DataViewConstructionUtils.SingleRowLoopDataView <TDst>(parent.Host, _parent._addedSchema);
appendedDataView.SetCurrentRowObject(_dst);
Func <int, bool> appendedPredicate =
col =>
{
col = _parent._bindings.AddedColumnIndices[col];
return(predicate(col));
};
_appendedRow = appendedDataView.GetRowCursor(appendedPredicate);
}
private IRow GetAppendedRow(Func <int, bool> active, TDst dst)
{
// REVIEW: This is quite odd (for a cursor to create an IDataView). Consider cleaning up your
// programming model for this. Note that you don't use the IDataView, only a cursor around a single row that
// is owned by this cursor. Seems like that cursor implementation could be decoupled from any IDataView class.
var appendedDataView = new DataViewConstructionUtils.SingleRowLoopDataView <TDst>(Host, _schema.AddedSchema);
appendedDataView.SetCurrentRowObject(dst);
return(appendedDataView.GetRowCursor(i => active(_schema.MapIinfoToCol(i))));
}