Class: OpenC3::SlipProtocol

Inherits:
TerminatedProtocol show all
Defined in:
lib/openc3/interfaces/protocols/slip_protocol.rb

Overview

Usage in plugin.txt:

INTERFACE …

PROTOCOL READ_WRITE SlipProtocol

Instance Attribute Summary

Attributes inherited from Protocol

#allow_empty_data, #extra, #interface

Instance Method Summary collapse

Methods inherited from BurstProtocol

#handle_sync_pattern, #log_discard, #reset, #write_packet

Methods inherited from Protocol

#connect_reset, #disconnect_reset, #post_write_interface, #protocol_cmd, #read_packet, #read_protocol_input_base, #read_protocol_output_base, #reset, #write_packet, #write_protocol_input_base, #write_protocol_output_base

Constructor Details

#initialize(start_char = nil, read_strip_characters = true, read_enable_escaping = true, write_enable_escaping = true, end_char = 0xC0, esc_char = 0xDB, esc_end_char = 0xDC, esc_esc_char = 0xDD, allow_empty_data = nil) ⇒ SlipProtocol

Note: Characters are expected to be given as integers

Parameters:

  • start_char (Integer/nil) (defaults to: nil) —

    Character to place at the start of frames (Defaults to nil)

  • read_strip_characters (true/false) (defaults to: true) —

    Strip off start_char and end_char from reads

  • read_enable_escaping (true/false) (defaults to: true) —

    Whether to enable or disable character escaping on reads

  • write_enable_escaping (true/false) (defaults to: true) —

    Whether to enable or disable character escaping on writes

  • end_char (Integer) (defaults to: 0xC0) —

    Character to place at the end of frames (Defaults to 0xC0)

  • esc_char (Integer) (defaults to: 0xDB) —

    Escape character (Defaults to 0xDB)

  • esc_end_char (Integer) (defaults to: 0xDC) —

    Character to Escape End character (Defaults to 0xDC)

  • esc_esc_char (Integer) (defaults to: 0xDD) —

    Character to Escape Escape character (Defaults to 0xDD)

  • allow_empty_data (true/false/nil) (defaults to: nil) —

    See Protocol#initialize



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# File 'lib/openc3/interfaces/protocols/slip_protocol.rb', line 41

def initialize(
  start_char = nil,
  read_strip_characters = true,
  read_enable_escaping = true,
  write_enable_escaping = true,
  end_char = 0xC0,
  esc_char = 0xDB,
  esc_end_char = 0xDC,
  esc_esc_char = 0xDD,
  allow_empty_data = nil)

  @start_char = ConfigParser.handle_nil(start_char)
  @start_char = [Integer(start_char)].pack('C') if @start_char
  @end_char = [Integer(end_char)].pack('C')
  @esc_char = [Integer(esc_char)].pack('C')
  @esc_end_char = [Integer(esc_end_char)].pack('C')
  @esc_esc_char = [Integer(esc_esc_char)].pack('C')
  @replace_end = @esc_char + @esc_end_char
  @replace_esc = @esc_char + @esc_esc_char
  @read_strip_characters = ConfigParser.handle_true_false(read_strip_characters)
  raise "read_strip_characters must be true or false" if @read_strip_characters != true and @read_strip_characters != false
  @read_enable_escaping = ConfigParser.handle_true_false(read_enable_escaping)
  raise "read_enable_escaping must be true or false" if @read_enable_escaping != true and @read_enable_escaping != false
  @write_enable_escaping = ConfigParser.handle_true_false(write_enable_escaping)
  raise "write_enable_escaping must be true or false" if @write_enable_escaping != true and @write_enable_escaping != false

  strip_read_termination = false
  discard_leading_bytes = 0
  if @start_char
    sync_pattern = sprintf("%0X", Integer(start_char))
  else
    sync_pattern = nil
  end
  fill_fields = false # Handled in write_data below

  super(
    "", # Write termination handled in write_data below
    sprintf("%0X", Integer(end_char)), # Expects Hex Character String
    strip_read_termination,
    discard_leading_bytes,
    sync_pattern,
    fill_fields,
    allow_empty_data
  )
end

Instance Method Details

#read_data(data, extra = nil) ⇒ Object 



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# File 'lib/openc3/interfaces/protocols/slip_protocol.rb', line 87

def read_data(data, extra = nil)
  data, extra = super(data, extra)
  return data, extra if data.length <= 0 or Symbol === data

  if @read_strip_characters
    if @start_char
      data = data[1..-1]
    end
    data = data[0..-2]
  end

  if @read_enable_escaping
    data = data.gsub(@replace_end, @end_char).gsub(@replace_esc, @esc_char)
  end

  return data, extra
end

#read_details ⇒ Object 



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# File 'lib/openc3/interfaces/protocols/slip_protocol.rb', line 155

def read_details
  result = super()
  result['start_char'] = @start_char.inspect
  result['end_char'] = @end_char.inspect
  result['esc_char'] = @esc_char.inspect
  result['esc_end_char'] = @esc_end_char.inspect
  result['esc_esc_char'] = @esc_esc_char.inspect
  result['read_strip_characters'] = @read_strip_characters
  result['read_enable_escaping'] = @read_enable_escaping
  return result
end

#reduce_to_single_packet ⇒ Object 



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# File 'lib/openc3/interfaces/protocols/slip_protocol.rb', line 121

def reduce_to_single_packet
  return :STOP if @data.length <= 0
  if @start_char
    index = @data[1..-1].index(@read_termination_characters)
    index = index + 1 if index
  else
    index = @data.index(@read_termination_characters)
  end

  # Reduce to packet data and setup current_data for next packet
  if index
    if index > 0
      packet_data = @data[0..(index + @read_termination_characters.length - 1)]
    else # @data begins with the termination characters
      packet_data = @data[0..(@read_termination_characters.length - 1)]
    end
    @data.replace(@data[(index + @read_termination_characters.length)..-1])
    return packet_data, @extra
  else
    return :STOP
  end
end

#write_data(data, extra = nil) ⇒ Object 



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# File 'lib/openc3/interfaces/protocols/slip_protocol.rb', line 105

def write_data(data, extra = nil)
  # Intentionally not calling super()

  if @write_enable_escaping
    data = data.gsub(@esc_char, @replace_esc).gsub(@end_char, @replace_end)
  end

  if @start_char
    data = @start_char + data
  end

  data << @end_char

  return data, extra
end

#write_details ⇒ Object 



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# File 'lib/openc3/interfaces/protocols/slip_protocol.rb', line 144

def write_details
  result = super()
  result['start_char'] = @start_char.inspect
  result['end_char'] = @end_char.inspect
  result['esc_char'] = @esc_char.inspect
  result['esc_end_char'] = @esc_end_char.inspect
  result['esc_esc_char'] = @esc_esc_char.inspect
  result['write_enable_escaping'] = @write_enable_escaping
  return result
end