Class: Arf::Wire::FrameReader

Inherits:
Object
  • Object
show all
Defined in:
lib/arf/wire/frame_reader.rb

Constant Summary collapse

STATES = 
%i[
  magic
  stream_id
  kind
  flags
  length
  payload
].freeze

Instance Method Summary collapse

Constructor Details

#initialize ⇒ FrameReader

Returns a new instance of FrameReader.



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# File 'lib/arf/wire/frame_reader.rb', line 15

def initialize
  @data = IO::Buffer.new
  @fr = Frame.new
  @state = :magic
  @c = 0
  @data.reset
end

Instance Method Details

#feed(b) ⇒ Object 



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# File 'lib/arf/wire/frame_reader.rb', line 37

def feed(b)
  case @state
  when :magic
    @data.write(b)
    return nil if @data.length < 3

    if @data.string != Frame::MAGIC
      @data.reset
      raise MagicNumberMismatchError
    end
    @data.reset
    @state = :stream_id

  when :stream_id
    @data.write(b)
    return nil if @data.length < 4

    @data.rewind
    @fr.stream_id = Wire.decode_uint32(@data)
    @data.reset
    @state = :kind

  when :kind
    raw_frame_kind = b
    frame_kind = Wire::FRAME_TO_SYMBOL[raw_frame_kind]
    raise UnknownFrameKindError, raw_frame_kind unless frame_kind

    @fr.frame_kind = frame_kind
    @state = :flags

  when :flags
    @fr.flags = b
    @state = :length

  when :length
    @data.write(b)
    return nil if @data.length < 2

    @data.rewind
    @fr.length = Wire.decode_uint16(@data)
    @data.reset
    @state = :payload
    if @fr.empty?
      @state = :magic
      frame = @fr
      @fr = Frame.new
      return frame
    end

  when :payload
    @data.write(b)
    return nil if @data.length < @fr.length

    @fr.payload = @data.extract
    @fr.payload.rewind
    @data = IO::Buffer.new
    @state = :magic
    @data.reset
    frame = @fr
    @fr = Frame.new
    return frame
  end

  nil
end

#feed_all(data) ⇒ Object 



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# File 'lib/arf/wire/frame_reader.rb', line 23

def feed_all(data)
  c = 0
  data.each_byte do |b|
    v = feed b
    c += 1
    if v && c < data.length
      raise "Short read: Read #{c} bytes of #{data.length}"
    elsif v
      return v
    end
  end
  nil
end