Class: MQTT::Packet::Connect

Inherits:
MQTT::Packet show all
Defined in:
lib/mqtt/packet.rb

Overview

Class representing an MQTT Connect Packet

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
}.freeze

Instance Attribute Summary collapse

Attributes inherited from MQTT::Packet

#body_length, #flags, #id, #version

Instance Method Summary collapse

Methods inherited from MQTT::Packet

create_from_header, #dup, #message_id, #message_id=, parse, parse_header, read, read_byte, #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/packet.rb', line 442

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

  case version
  when '3.1.0', '3.1'
    self.protocol_name ||= 'MQIsdp'
    self.protocol_level ||= 0x03
  when '3.1.1'
    self.protocol_name ||= 'MQTT'
    self.protocol_level ||= 0x04
  else
    raise ArgumentError, "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/packet.rb', line 405

def clean_session
  @clean_session
end

#client_id ⇒ Object

The client identifier string



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# File 'lib/mqtt/packet.rb', line 402

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/packet.rb', line 408

def keep_alive
  @keep_alive
end

#password ⇒ Object

The password for authenticating with the server



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# File 'lib/mqtt/packet.rb', line 426

def password
  @password
end

#protocol_level ⇒ Object

The version number of the protocol



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# File 'lib/mqtt/packet.rb', line 399

def protocol_level
  @protocol_level
end

#protocol_name ⇒ Object

The name of the protocol



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# File 'lib/mqtt/packet.rb', line 396

def protocol_name
  @protocol_name
end

#username ⇒ Object

The username for authenticating with the server



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# File 'lib/mqtt/packet.rb', line 423

def username
  @username
end

#will_payload ⇒ Object

The payload of the Will message



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# File 'lib/mqtt/packet.rb', line 420

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/packet.rb', line 414

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/packet.rb', line 417

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/packet.rb', line 411

def will_topic
  @will_topic
end

Instance Method Details

#encode_body ⇒ Object

Get serialisation of packet’s body



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# File 'lib/mqtt/packet.rb', line 458

def encode_body
  body = ''

  if @version == '3.1.0'
    raise 'Client identifier too short while serialising packet' if @client_id.nil? || @client_id.bytesize < 1
    raise 'Client identifier too long when serialising packet' if @client_id.bytesize > 23
  end

  body += encode_string(@protocol_name)
  body += encode_bytes(@protocol_level.to_i)

  raise 'Invalid keep-alive value: cannot be less than 0' if @keep_alive < 0

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

#inspect ⇒ Object

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



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# File 'lib/mqtt/packet.rb', line 525

def inspect
  str = "\#<#{self.class}: " \
        "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/packet.rb', line 494

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 ProtocolException, "Unsupported protocol: #{@protocol_name}/#{@protocol_level}"
  end

  @connect_flags = shift_byte(buffer)
  @clean_session = ((@connect_flags & 0x02) >> 1) == 0x01
  @keep_alive = shift_short(buffer)
  @client_id = shift_string(buffer)
  if ((@connect_flags & 0x04) >> 2) == 0x01
    # Last Will and Testament
    @will_qos = ((@connect_flags & 0x18) >> 3)
    @will_retain = ((@connect_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
  @username = shift_string(buffer) if ((@connect_flags & 0x80) >> 7) == 0x01 && buffer.bytesize > 0
  if ((@connect_flags & 0x40) >> 6) == 0x01 && buffer.bytesize > 0 # rubocop: disable Style/GuardClause
    @password = shift_string(buffer)
  end
end

#protocol_version ⇒ Object

Deprecated.

Please use #protocol_level instead



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# File 'lib/mqtt/packet.rb', line 538

def protocol_version
  protocol_level
end

#protocol_version=(args) ⇒ Object

Deprecated.

Please use #protocol_level= instead



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# File 'lib/mqtt/packet.rb', line 543

def protocol_version=(args)
  self.protocol_level = args
end