class EventMachine::Protocols::LineAndTextProtocol

def set_binary_mode size = nil


Specifiyng zero for the limit will cause an immediate transition back to line mode.
Specifying nil for the limit (the default) means there is no limit.
(in which case we'll pass up a partial).
pass it upstream until we've seen it all, or until there is an unbind
If a limit is given, we'll hold the incoming binary data and not
data and passed to the upstream protocol handler as we receive it.
If the limit is nil, then ALL subsequent data will be treated as binary
This recycles all the data currently waiting in the line buffer, if any.
Set up to read the supplied number of binary bytes. 
def set_binary_mode size = nil
  if @lbp_mode == :lines
    if size == 0
      receive_binary_data("") if respond_to?(:receive_binary_data)
      # Do no more work here. Stay in line mode and keep consuming data.
    else
      @lbp_binary_limit = size.to_i # (nil will be stored as zero)
      if @lbp_binary_limit > 0
        raise "Overlength" if @lbp_binary_limit > MaxBinaryLength # arbitrary sanity check
        @lbp_binary_buffer = "\0" * @lbp_binary_limit
        @lbp_binary_bytes_received = 0
      end
      @lbp_mode = :binary
      receive_data @lpb_buffer.flush
    end
  else
    raise "invalid operation"
  end
end