Class: MqttRails::Packet::Connect

Inherits:
Base
  • Object
show all
Defined in:
lib/mqtt_rails/packet/connect.rb

Constant Summary collapse

ATTR_DEFAULTS =

Default attribute values

{
  :client_id     => nil,
  :clean_session => true,
  :keep_alive    => 15,
  :will_topic    => nil,
  :will_qos      => 0,
  :will_retain   => false,
  :will_payload  => '',
  :username      => nil,
  :password      => nil,
}

Instance Attribute Summary collapse

Attributes inherited from Base

#body_length, #flags, #id, #version

Instance Method Summary collapse

Methods inherited from Base

create_from_header, parse, parse_header, read, #to_s, #type_id, #type_name, #update_attributes, #validate_flags

Constructor Details

#initialize(args = {}) ⇒ Connect

Create a new Client Connect packet



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# File 'lib/mqtt_rails/packet/connect.rb', line 70

def initialize(args={})
  super(ATTR_DEFAULTS.merge(args))

  if version == '3.1.0' || version == '3.1'
    self.protocol_name ||= 'MQIsdp'
    self.protocol_level ||= 0x03
  elsif version == '3.1.1'
    self.protocol_name ||= 'MQTT'
    self.protocol_level ||= 0x04
  else
    raise MqttRails::PacketFormatException.new(
            "Unsupported protocol version: #{version}")
  end
end

Instance Attribute Details

#clean_session ⇒ Object

Set to false to keep a persistent session with the server



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# File 'lib/mqtt_rails/packet/connect.rb', line 33

def clean_session
  @clean_session
end

#client_id ⇒ Object

The client identifier string



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# File 'lib/mqtt_rails/packet/connect.rb', line 30

def client_id
  @client_id
end

#keep_alive ⇒ Object

Period the server should keep connection open for between pings



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# File 'lib/mqtt_rails/packet/connect.rb', line 36

def keep_alive
  @keep_alive
end

#password ⇒ Object

The password for authenticating with the server



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# File 'lib/mqtt_rails/packet/connect.rb', line 54

def password
  @password
end

#protocol_level ⇒ Object

The version number of the protocol



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# File 'lib/mqtt_rails/packet/connect.rb', line 27

def protocol_level
  @protocol_level
end

#protocol_name ⇒ Object

The name of the protocol



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# File 'lib/mqtt_rails/packet/connect.rb', line 24

def protocol_name
  @protocol_name
end

#username ⇒ Object

The username for authenticating with the server



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# File 'lib/mqtt_rails/packet/connect.rb', line 51

def username
  @username
end

#will_payload ⇒ Object

The payload of the Will message



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# File 'lib/mqtt_rails/packet/connect.rb', line 48

def will_payload
  @will_payload
end

#will_qos ⇒ Object

The QoS level to send the Will message as



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# File 'lib/mqtt_rails/packet/connect.rb', line 42

def will_qos
  @will_qos
end

#will_retain ⇒ Object

Set to true to make the Will message retained



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# File 'lib/mqtt_rails/packet/connect.rb', line 45

def will_retain
  @will_retain
end

#will_topic ⇒ Object

The topic name to send the Will message to



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# File 'lib/mqtt_rails/packet/connect.rb', line 39

def will_topic
  @will_topic
end

Instance Method Details

#check_version ⇒ Object 



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# File 'lib/mqtt_rails/packet/connect.rb', line 109

def check_version
  if @version == '3.1.0'
    if @client_id.nil? || @client_id.bytesize < 1
      raise MqttRails::PacketFormatException.new(
              "Client identifier too short while serialising packet")
    elsif @client_id.bytesize > 23
      raise MqttRails::PacketFormatException.new(
              "Client identifier too long when serialising packet")
    end
  end
end

#encode_body ⇒ Object

Get serialisation of packet’s body



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# File 'lib/mqtt_rails/packet/connect.rb', line 86

def encode_body
  body = ''
  check_version
  body += encode_string(@protocol_name)
  body += encode_bytes(@protocol_level.to_i)
  if @keep_alive < 0
    raise MqttRails::PacketFormatException.new(
            "Invalid keep-alive value: cannot be less than 0")
  end

  body += encode_flags(@connect_flags)
  body += encode_short(@keep_alive)
  body += encode_string(@client_id)
  unless will_topic.nil?
    body += encode_string(@will_topic)
    # The MQTT v3.1 specification says that the payload is a UTF-8 string
    body += encode_string(@will_payload)
  end
  body += encode_string(@username) unless @username.nil?
  body += encode_string(@password) unless @password.nil?
  body
end

#encode_flags(flags) ⇒ Object 



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# File 'lib/mqtt_rails/packet/connect.rb', line 121

def encode_flags(flags)
  # Set the Connect flags
  flags = 0
  flags |= 0x02 if @clean_session
  flags |= 0x04 unless @will_topic.nil?
  flags |= ((@will_qos & 0x03) << 3)
  flags |= 0x20 if @will_retain
  flags |= 0x40 unless @password.nil?
  flags |= 0x80 unless @username.nil?
  encode_bytes(flags)
end

#inspect ⇒ Object

Returns a human readable string, summarising the properties of the packet



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# File 'lib/mqtt_rails/packet/connect.rb', line 172

def inspect
  str = "\#<#{self.class}: "
  str += "keep_alive=#{keep_alive}"
  str += ", clean" if clean_session
  str += ", client_id='#{client_id}'"
  str += ", username='#{username}'" unless username.nil?
  str += ", password=..." unless password.nil?
  str += ">"
end

#parse_body(buffer) ⇒ Object

Parse the body (variable header and payload) of a Connect packet



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# File 'lib/mqtt_rails/packet/connect.rb', line 134

def parse_body(buffer)
  super(buffer)
  @protocol_name = shift_string(buffer)
  @protocol_level = shift_byte(buffer).to_i
  if @protocol_name == 'MQIsdp' && @protocol_level == 3
    @version = '3.1.0'
  elsif @protocol_name == 'MQTT' && @protocol_level == 4
    @version = '3.1.1'
  else
    raise MqttRails::PacketFormatException.new(
            "Unsupported protocol: #{@protocol_name}/#{@protocol_level}")
  end

  @connect_flags = shift_byte(buffer)
  @keep_alive = shift_short(buffer)
  @client_id = shift_string(buffer)
  parse_connect_flags(@connect_flag, buffer)
end

#parse_connect_flags(flags, buffer) ⇒ Object 



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# File 'lib/mqtt_rails/packet/connect.rb', line 153

def parse_connect_flags(flags, buffer)
  @clean_session = ((@connect_flags & 0x02) >> 1) == 0x01
  if ((flags & 0x04) >> 2) == 0x01
    # Last Will and Testament
    @will_qos = ((flags & 0x18) >> 3)
    @will_retain = ((flags & 0x20) >> 5) == 0x01
    @will_topic = shift_string(buffer)
    # The MQTT v3.1 specification says that the payload is a UTF-8 string
    @will_payload = shift_string(buffer)
  end
  if ((@connect_flags & 0x80) >> 7) == 0x01 && buffer.bytesize > 0
    @username = shift_string(buffer)
  end
  if ((@connect_flags & 0x40) >> 6) == 0x01 && buffer.bytesize > 0
    @password = shift_string(buffer)
  end
end