Module: Takagi::Network::Framing::Tcp

Defined in:
lib/takagi/network/framing/tcp.rb

Overview

RFC 8323 CoAP over TCP framing with variable-length encoding

Class Method Summary collapse

Class Method Details

.decode(data) ⇒ Message::Inbound

Decode framed TCP message

Parameters:

  • data (String) —

    Framed binary data

Returns:



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# File 'lib/takagi/network/framing/tcp.rb', line 22

def decode(data)
  Message::Inbound.new(data, transport: :tcp)
end

.encode(message) ⇒ String

Encode message with RFC 8323 framing

Parameters:

Returns:

  • (String) —

    Framed binary data



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# File 'lib/takagi/network/framing/tcp.rb', line 12

def encode(message)
  # Build base message
  packet = build_base_message(message)
  # Add RFC 8323 framing
  frame(packet)
end

.read_from_socket(socket, logger: nil) ⇒ String?

Read a complete message from socket

Parameters:

  • socket (TCPSocket) —

    Socket to read from

  • logger (Logger) (defaults to: nil) —

    Optional logger for debugging

Returns:

  • (String, nil) —

    Complete framed message or nil



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# File 'lib/takagi/network/framing/tcp.rb', line 30

def read_from_socket(socket, logger: nil)
  first_byte_data = socket.read(1)
  return nil if first_byte_data.nil? || first_byte_data.empty?

  first_byte = first_byte_data.unpack1('C')
  len_nibble = (first_byte >> 4) & 0x0F
  tkl = first_byte & 0x0F

  logger&.debug "read_from_socket: first_byte=0x#{first_byte.to_s(16)}, len_nibble=#{len_nibble}, tkl=#{tkl}"

  length = read_length(socket, len_nibble, logger: logger)
  return nil unless length

  logger&.debug "read_from_socket: message length=#{length} bytes"

  # Read: Code (1) + Token (tkl) + Options + Payload (length)
  bytes_to_read = 1 + tkl + length
  data = +''.b
  remaining = bytes_to_read

  while remaining.positive?
    begin
      chunk = socket.readpartial(remaining)
    rescue IO::WaitReadable
      IO.select([socket])
      retry
    rescue EOFError
      logger&.error "read_from_socket: Incomplete message (expected #{bytes_to_read}, got #{data.bytesize})"
      return nil
    end

    data << chunk
    remaining -= chunk.bytesize
  end

  logger&.debug "read_from_socket: Successfully read #{bytes_to_read} bytes"

  first_byte_data + data
rescue IOError, Errno::ECONNRESET => e
  logger&.debug "read_from_socket: Socket error (#{e.class}: #{e.message})"
  nil
end