class WebSocket::Frame::Handler::Handler75

def decode_frame
  return if @frame.data.size.zero?
  pointer = 0
  frame_type = @frame.data.getbyte(pointer)
  pointer += 1
  if (frame_type & 0x80) == 0x80
    # If the high-order bit of the /frame type/ byte is set
    length = 0
    loop do
      return unless @frame.data.getbyte(pointer)
      b = @frame.data.getbyte(pointer)
      pointer += 1
      b_v = b & 0x7F
      length = length * 128 + b_v
      break unless (b & 0x80) == 0x80
    end
    raise WebSocket::Error::Frame::TooLong if length > ::WebSocket.max_frame_size
    unless @frame.data.getbyte(pointer + length - 1).nil?
      # Straight from spec - I'm sure this isn't crazy...
      # 6. Read /length/ bytes.
      # 7. Discard the read bytes.
      @frame.instance_variable_set '@data', @frame.data[(pointer + length)..-1]
      # If the /frame type/ is 0xFF and the /length/ was 0, then close
      if length.zero?
        @frame.class.new(version: @frame.version, type: :close, decoded: true)
      end
    end
  else
    # If the high-order bit of the /frame type/ byte is _not_ set
    raise WebSocket::Error::Frame::Invalid if @frame.data.getbyte(0) != 0x00
    # Addition to the spec to protect against malicious requests
    raise WebSocket::Error::Frame::TooLong if @frame.data.size > ::WebSocket.max_frame_size
    msg = @frame.data.slice!(/\A\x00[^\xff]*\xff/)
    if msg
      msg.gsub!(/\A\x00|\xff\z/, '')
      msg.force_encoding('UTF-8')
      @frame.class.new(version: @frame.version, type: :text, data: msg, decoded: true)
    end
  end
end

def encode_frame
  case @frame.type
  when :close then "\xff\x00"
  when :text then
    ary = ["\x00", @frame.data, "\xff"]
    ary.map { |s| s.encode('UTF-8', 'UTF-8', invalid: :replace) }
    ary.join
  else raise WebSocket::Error::Frame::UnknownFrameType
  end
end

def supported_frames
  %i[text close]
end