Class: RubyFit::MessageWriter

Inherits:
Object
  • Object
show all
Extended by:
Helpers
Defined in:
lib/rubyfit/message_writer.rb

Constant Summary collapse

FIT_PROTOCOL_VERSION =

major 1, minor 0

0x10
FIT_PROFILE_VERSION =

major 1, minor 52

1 * 100 + 52
MESSAGE_DEFINITIONS = 
{
  file_id: {
    id: 0,
    fields: {
      serial_number: { id: 3, type: RubyFit::Type.uint32z, required: true },
      time_created: { id: 4, type: RubyFit::Type.timestamp, required: true },
      manufacturer: { id: 1, type: RubyFit::Type.uint16 }, # See FIT_MANUFACTURER_*
      product: { id: 2, type: RubyFit::Type.uint16 },
      type: { id: 0, type: RubyFit::Type.enum, required: true }, # See FIT_FILE_*
    }
  },
  course: {
    id: 31,
    fields: {
      name: { id: 5, type: RubyFit::Type.string(16), required: true },
    }
  },
  lap: {
    id: 19,
    fields: {
      timestamp: { id: 253, type: RubyFit::Type.timestamp, required: true},
      start_time: { id: 2, type: RubyFit::Type.timestamp, required: true},
      total_elapsed_time: { id: 7, type: RubyFit::Type.duration, required: true }, 
      total_timer_time: { id: 8, type: RubyFit::Type.duration, required: true }, 
      start_y: { id: 3, type: RubyFit::Type.semicircles },
      start_x: { id: 4, type: RubyFit::Type.semicircles },
      end_y: { id: 5, type: RubyFit::Type.semicircles },
      end_x: { id: 6, type: RubyFit::Type.semicircles },
      total_distance: { id: 9, type: RubyFit::Type.centimeters },
    },
  },
  course_point: {
    id: 32,
    fields: {
      timestamp: { id: 1, type: RubyFit::Type.timestamp, required: true },
      y: { id: 2, type: RubyFit::Type.semicircles, required: true },
      x: { id: 3, type: RubyFit::Type.semicircles, required: true },
      distance: { id: 4, type: RubyFit::Type.centimeters },
      name: { id: 6, type: RubyFit::Type.string(16) },
      message_index: { id: 254, type: RubyFit::Type.uint16 },
      type: { id: 5, type: RubyFit::Type.enum, values: RubyFit::MessageConstants::COURSE_POINT_TYPE, required: true }
    },
  },
  record: {
    id: 20,
    fields: {
      timestamp: { id: 253, type: RubyFit::Type.timestamp, required: true },
      y: { id: 0, type: RubyFit::Type.semicircles, required: true },
      x: { id: 1, type: RubyFit::Type.semicircles, required: true },
      distance: { id: 5, type: RubyFit::Type.centimeters },
      elevation: { id: 2, type: RubyFit::Type.altitude },
    }
  },
  event: {
    id: 21,
    fields: {
      timestamp: { id: 253, type: RubyFit::Type.timestamp, required: true },
      event: { id: 0, type: RubyFit::Type.enum, values: RubyFit::MessageConstants::EVENT, required: true },
      event_type: { id: 1, type: RubyFit::Type.enum, values: RubyFit::MessageConstants::EVENT_TYPE, required: true },
      event_group: { id: 4, type: RubyFit::Type.uint8 },
    }
  }
}

Constants included from Helpers

Helpers::DEGREES_TO_SEMICIRCLES, Helpers::GARMIN_TIME_OFFSET

Class Method Summary collapse

Methods included from Helpers

bytes2hex, bytes2num, bytes2str, deg2semicircles, fit2unix_timestamp, make_message_header, num2bytes, semicircles2deg, str2bytes, unix2fit_timestamp

Class Method Details

.crc(crc_value) ⇒ Object 



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# File 'lib/rubyfit/message_writer.rb', line 141

def self.crc(crc_value)
  pack_bytes do |bytes|
    bytes.push(*num2bytes(crc_value, 2, false)) # Little endian
  end
end

.data_message(type, local_num, values) ⇒ Object 



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# File 'lib/rubyfit/message_writer.rb', line 93

def self.data_message(type, local_num, values)
  pack_bytes do |bytes|
    message_data = MESSAGE_DEFINITIONS[type]
    bytes << header_byte(local_num, false)
    message_data[:fields].each do |field, info|
      field_type = info[:type]
      value = values[field]
      if info[:required] && value.nil?
        raise ArgumentError.new("Missing required field '#{field}' in #{type} data message values")
      end

      if info[:values]
        value = info[:values][value]
        if value.nil?
          raise ArgumentError.new("Invalid value for '#{field}' in #{type} data message values")
        end
      end

      value_bytes = value ? field_type.val2bytes(value) : field_type.default_bytes
      bytes.push(*value_bytes)
    end
  end
end

.data_message_size(type) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/rubyfit/message_writer.rb', line 123

def self.data_message_size(type)
  message_data = MESSAGE_DEFINITIONS[type]
  raise ArgumentError.new("Unknown message type '#{type}'") unless message_data
  1 + message_data[:fields].values.map{|info| info[:type].byte_count}.reduce(&:+)
end

.definition_message(type, local_num) ⇒ Object 



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# File 'lib/rubyfit/message_writer.rb', line 75

def self.definition_message(type, local_num)
  pack_bytes do |bytes|
    message_data = MESSAGE_DEFINITIONS[type]
    bytes << header_byte(local_num, true)
    bytes << 0x00 # Reserved uint8
    bytes << 0x01 # Big endian
    bytes.push(*num2bytes(message_data[:id], 2)) # Global message ID
    bytes << message_data[:fields].size # Field count

    message_data[:fields].each do |field, info|
      type = info[:type]
      bytes << info[:id]
      bytes << type.byte_count
      bytes << type.fit_id
    end
  end
end

.definition_message_size(type) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/rubyfit/message_writer.rb', line 117

def self.definition_message_size(type)
  message_data = MESSAGE_DEFINITIONS[type]
  raise ArgumentError.new("Unknown message type '#{type}'") unless message_data
  6 + message_data[:fields].count * 3
end

.file_header(data_byte_count = 0) ⇒ Object 



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# File 'lib/rubyfit/message_writer.rb', line 129

def self.file_header(data_byte_count = 0) 
  pack_bytes do |bytes|
    bytes << 14 # Header size
    bytes << FIT_PROTOCOL_VERSION # Protocol version
    bytes.push(*num2bytes(FIT_PROFILE_VERSION, 2).reverse) # Profile version (little endian)
    bytes.push(*num2bytes(data_byte_count, 4).reverse) # Data size (little endian)
    bytes.push(*str2bytes(".FIT", 5).take(4)) # Data Type ASCII, no terminator
    crc = 0 #RubyFit::CRC.update_crc(0, bytes2str(bytes))
    bytes.push(*num2bytes(crc, 2).reverse) # Header CRC (little endian)
  end
end

.header_byte(local_number, definition) ⇒ Object

Internal



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# File 'lib/rubyfit/message_writer.rb', line 149

def self.header_byte(local_number, definition)
  local_number & 0xF | (definition ? 0x40 : 0x00)
end

.pack_bytes {|bytes| ... } ⇒ Object

Yields:

  • (bytes) 


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# File 'lib/rubyfit/message_writer.rb', line 153

def self.pack_bytes
  bytes = []
  yield bytes
  bytes.pack("C*")
end