private Action <long> MakePinger(Row input, TState state)
{
_host.AssertValue(input);
var srcGetter = input.GetGetter <TInput>(_inputColumnIndex);
Action <long> pinger = (long rowPosition) =>
{
TInput src = default;
srcGetter(ref src);
state.UpdateState(ref src, rowPosition, _parent.WindowSize > 0);
};
return(pinger);
}