module OpenSSL::Buffering

def read_nonblock(maxlen, buf=nil)

def read_nonblock(maxlen, buf=nil)
  if maxlen == 0
    if buf
      buf.clear
      return buf
    else
      return ""
    end
  end
  if @rbuffer.empty?
    return sysread_nonblock(maxlen, buf)
  end
  ret = consume_rbuff(maxlen)
  if buf
    buf.replace(ret)
    ret = buf
  end
  raise EOFError if ret.empty?
  ret
end