Class: LiveF1::Packet::Header

Inherits:
Struct
  • Object
show all
Defined in:
lib/live_f1/packet/header.rb

Overview

A Header uses 2 bytes of data from a live timing stream to determine all the necessary information about the packet which follows it.

Defined Under Namespace

Classes: MissingData, MissingEventType, UnexpectedPacket, UnknownPacket

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#bytes ⇒ Object (readonly)

Returns the value of attribute bytes.



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# File 'lib/live_f1/packet/header.rb', line 19

def bytes
  @bytes
end

#car ⇒ Object

Returns the value of attribute car

Returns:

  • (Object) —

    the current value of car



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# File 'lib/live_f1/packet/header.rb', line 18

def car
  @car
end

#data ⇒ Object

Returns the value of attribute data

Returns:

  • (Object) —

    the current value of data



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# File 'lib/live_f1/packet/header.rb', line 18

def data
  @data
end

#event_type ⇒ Object

Returns the value of attribute event_type

Returns:

  • (Object) —

    the current value of event_type



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# File 'lib/live_f1/packet/header.rb', line 18

def event_type
  @event_type
end

#packet_type ⇒ Object

Returns the value of attribute packet_type

Returns:

  • (Object) —

    the current value of packet_type



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# File 'lib/live_f1/packet/header.rb', line 18

def packet_type
  @packet_type
end

Class Method Details

.from_source(source, event_type) ⇒ Object

Raises:



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# File 'lib/live_f1/packet/header.rb', line 21

def self.from_source source, event_type
  bytes = source.read_bytes(2)
  raise MissingData, "No data from #{source.inspect}" unless bytes.to_s.length == 2
  bits = bytes.to_s.reverse.unpack("B*").first
  _, data, packet_type, car = bits.match(/^(.{7})(.{4})(.{5})$/).to_a.map { |s| s.to_i(2) }

  new(data, packet_type, car, event_type).tap do |header|
    # TODO: Maybe need a nicer way of setting this
    header.instance_variable_set "@bytes", bytes
  end
end

Instance Method Details

#car? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/live_f1/packet/header.rb', line 33

def car?
  !car.zero?
end

#packet_klass ⇒ Object 



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# File 'lib/live_f1/packet/header.rb', line 37

def packet_klass
  case
  when car?
    case event_type
    when Event::RACE
      case packet_type
      when 0 then Packet::Car::PositionUpdate
      when 1 then Packet::Car::Position
      when 2 then Packet::Car::Number
      when 3 then Packet::Car::Driver
      when 4 then Packet::Car::Gap
      when 5 then Packet::Car::Interval
      when 6 then Packet::Car::LapTime
      when 7 then Packet::Car::Sector1
      when 8 then Packet::Car::PitLap1
      when 9 then Packet::Car::Sector2
      when 10 then Packet::Car::PitLap2
      when 11 then Packet::Car::Sector3
      when 12 then Packet::Car::PitLap3
      when 13 then Packet::Car::NumPits
      when 14 then nil
      when 15 then Packet::Car::PositionHistory
      end
    when Event::PRACTICE
      case packet_type
      when 0 then Packet::Car::PositionUpdate
      when 1 then Packet::Car::Position
      when 2 then Packet::Car::Number
      when 3 then Packet::Car::Driver
      when 4 then Packet::Car::BestLapTime
      when 5 then Packet::Car::Gap
      when 6 then Packet::Car::Sector1
      when 7 then Packet::Car::Sector2
      when 8 then Packet::Car::Sector3
      when 9 then Packet::Car::LapCount
      when 10 then Packet::Car::LapCount
      when 15 then nil
      end
    when Event::QUALIFYING
      case packet_type
      when 0 then Packet::Car::PositionUpdate
      when 1 then Packet::Car::Position
      when 2 then Packet::Car::Number
      when 3 then Packet::Car::Driver
      when 4 then Packet::Car::Period1
      when 5 then Packet::Car::Period2
      when 6 then Packet::Car::Period3
      when 7 then Packet::Car::Sector1
      when 8 then Packet::Car::Sector2
      when 9 then Packet::Car::Sector3
      when 10 then Packet::Car::LapCount
      when 15 then nil
      end
    else
      raise MissingEventType, "Unrecognised event type (#{event_type.inspect}), can't determine class for car packet #{packet_type.inspect}"
    end
  else
    case packet_type
    when 0 then Packet::Unknown
    when 1 then Packet::Sys::SessionStart
    when 2 then Packet::Sys::KeyFrame
    when 3 then Packet::Unknown
    when 4 then Packet::Sys::Commentary
    when 5 then Packet::Unknown
    when 6 then Packet::Sys::Notice
    when 7 then Packet::Sys::Timestamp
    when 8 then nil # Packet::Unknown
    when 9 then Packet::Sys::Weather
    when 10 then Packet::Sys::Speed
    when 11 then Packet::Sys::TrackStatus
    when 12 then Packet::Sys::Copyright
    when 13 then nil # Packet::Unknown
    when 14 then nil # Packet::Unknown
    when 15 then nil # Packet::Unknown
    end
  end or raise UnexpectedPacket, "Unexpected #{car? ? 'car' : 'sys'} packet type #{packet_type.inspect} for #{Event::Type.name_for event_type} event"
end