class WebSocket::Driver::Hybi

def parse_length(data)
  @masked = (data & MASK) == MASK
  if @require_masking and not @masked
    return fail(:unacceptable, 'Received unmasked frame but masking is required')
  end
  @length = (data & LENGTH)
  if @length <= 125
    @stage = @masked ? 3 : 4
  else
    @length_size = (@length == 126) ? 2 : 8
    @stage       = 2
  end
end