public Cursor(ExtStatefulFilterTransform <TSrc, TDst, TState> parent, RowCursor <TSrc> input, IEnumerable <DataViewSchema.Column> columnsNeeded)
: base(parent.Host)
{
Ch.AssertValue(input);
Ch.AssertValue(columnsNeeded);
_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);
parent._initStateAction?.Invoke(_state);
var appendedDataView = new DataViewConstructionUtils.SingleRowLoopDataView <TDst>(parent.Host, _parent._addedSchema);
appendedDataView.SetCurrentRowObject(_dst);
var columnNames = columnsNeeded.Select(c => c.Name);
_appendedRow = appendedDataView.GetRowCursor(appendedDataView.Schema.Where(c => !c.IsHidden && columnNames.Contains(c.Name)));
}
/// <summary>
/// The 'reapply' constructor.
/// </summary>
private ExtStatefulFilterTransform(IHostEnvironment env, ExtStatefulFilterTransform <TSrc, TDst, TState> transform, IDataView newSource)
: base(env, RegistrationName, transform)
{
Host.AssertValue(transform);
Host.AssertValue(newSource);
_source = newSource;
_filterFunc = transform._filterFunc;
_typedSource = TypedCursorable <TSrc> .Create(Host, newSource, false, transform._inputSchemaDefinition);
_addedSchema = transform._addedSchema;
_bindings = new ColumnBindings(newSource.Schema, DataViewConstructionUtils.GetSchemaColumns(_addedSchema));
}
