Module: EventMachine::WebSocket::Framing03

11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95

# File 'lib/em-websocket/framing03.rb', line 11

def process_data(newdata)
  error = false

  while !error && @data.size > 1
    pointer = 0

    more = ((@data.getbyte(pointer) & 0b10000000) == 0b10000000) ^ fin
    # Ignoring rsv1-3 for now
    opcode = @data.getbyte(0) & 0b00001111
    pointer += 1

    # Ignoring rsv4
    length = @data.getbyte(pointer) & 0b01111111
    pointer += 1

    payload_length = case length
    when 127 # Length defined by 8 bytes
      # Check buffer size
      if @data.getbyte(pointer+8-1) == nil
        debug [:buffer_incomplete, @data]
        error = true
        next
      end
      
      # Only using the last 4 bytes for now, till I work out how to
      # unpack 8 bytes. I'm sure 4GB frames will do for now :)
      l = @data[(pointer+4)..(pointer+7)].unpack('N').first
      pointer += 8
      l
    when 126 # Length defined by 2 bytes
      # Check buffer size
      if @data.getbyte(pointer+2-1) == nil
        debug [:buffer_incomplete, @data]
        error = true
        next
      end
      
      l = @data[pointer..(pointer+1)].unpack('n').first
      pointer += 2
      l
    else
      length
    end

    if payload_length > @connection.max_frame_size
      raise WSMessageTooBigError, "Frame length too long (#{payload_length} bytes)"
    end

    # Check buffer size
    if @data.getbyte(pointer+payload_length-1) == nil
      debug [:buffer_incomplete, @data]
      error = true
      next
    end

    # Throw away data up to pointer
    @data.slice!(0...pointer)

    # Read application data
    application_data = @data.slice!(0...payload_length)

    frame_type = opcode_to_type(opcode)

    if frame_type == :continuation && !@frame_type
      raise WSProtocolError, 'Continuation frame not expected'
    end

    if more
      debug [:moreframe, frame_type, application_data]
      @application_data_buffer << application_data
      # The message type is passed in the first frame
      @frame_type ||= frame_type
    else
      # Message is complete
      if frame_type == :continuation
        @application_data_buffer << application_data
        message(@frame_type, '', @application_data_buffer)
        @application_data_buffer = ''
        @frame_type = nil
      else
        message(frame_type, '', application_data)
      end
    end
  end # end while
end

97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125

# File 'lib/em-websocket/framing03.rb', line 97

def send_frame(frame_type, application_data)
  debug [:sending_frame, frame_type, application_data]

  if @state == :closing && data_frame?(frame_type)
    raise WebSocketError, "Cannot send data frame since connection is closing"
  end

  frame = ''

  opcode = type_to_opcode(frame_type)
  byte1 = opcode # since more, rsv1-3 are 0
  frame << byte1

  length = application_data.size
  if length <= 125
    byte2 = length # since rsv4 is 0
    frame << byte2
  elsif length < 65536 # write 2 byte length
    frame << 126
    frame << [length].pack('n')
  else # write 8 byte length
    frame << 127
    frame << [length >> 32, length & 0xFFFFFFFF].pack("NN")
  end

  frame << application_data

  @connection.send_data(frame)
end

127
128
129

# File 'lib/em-websocket/framing03.rb', line 127

def send_text_frame(data)
  send_frame(:text, data)
end