module BinData::IO::Common

def buffer_limited_n(n)
  if @buffer_end_points
    if n.nil? || n > 0
      max = @buffer_end_points[1] - offset
      n = max if n.nil? || n > max
    else
      min = @buffer_end_points[0] - offset
      n = min if n < min
    end
  end
  n
end