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,
}

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, #message_id, #message_id=, 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/packet.rb', line 466

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

  if version == '3.1.0' or 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 ArgumentError.new("Unsupported protocol version: #{version}")
  end
end

Instance Attribute Details

#clean_sessionObject

Set to false to keep a persistent session with the server


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# File 'lib/mqtt/packet.rb', line 429

def clean_session
  @clean_session
end

#client_idObject

The client identifier string


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

def client_id
  @client_id
end

#keep_aliveObject

Period the server should keep connection open for between pings


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# File 'lib/mqtt/packet.rb', line 432

def keep_alive
  @keep_alive
end

#passwordObject

The password for authenticating with the server


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# File 'lib/mqtt/packet.rb', line 450

def password
  @password
end

#protocol_levelObject

The version number of the protocol


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

def protocol_level
  @protocol_level
end

#protocol_nameObject

The name of the protocol


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

def protocol_name
  @protocol_name
end

#usernameObject

The username for authenticating with the server


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# File 'lib/mqtt/packet.rb', line 447

def username
  @username
end

#will_payloadObject

The payload of the Will message


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# File 'lib/mqtt/packet.rb', line 444

def will_payload
  @will_payload
end

#will_qosObject

The QoS level to send the Will message as


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# File 'lib/mqtt/packet.rb', line 438

def will_qos
  @will_qos
end

#will_retainObject

Set to true to make the Will message retained


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# File 'lib/mqtt/packet.rb', line 441

def will_retain
  @will_retain
end

#will_topicObject

The topic name to send the Will message to


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# File 'lib/mqtt/packet.rb', line 435

def will_topic
  @will_topic
end

Instance Method Details

#encode_bodyObject

Get serialisation of packet's body


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# File 'lib/mqtt/packet.rb', line 481

def encode_body
  body = ''
  if @version == '3.1.0'
    if @client_id.nil? or @client_id.bytesize < 1
      raise "Client identifier too short while serialising packet"
    elsif @client_id.bytesize > 23
      raise "Client identifier too long when serialising packet"
    end
  end
  body += encode_string(@protocol_name)
  body += encode_bytes(@protocol_level.to_i)

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

  # 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?
  return body
end

#inspectObject

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


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# File 'lib/mqtt/packet.rb', line 555

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/packet.rb', line 520

def parse_body(buffer)
  super(buffer)
  @protocol_name = shift_string(buffer)
  @protocol_level = shift_byte(buffer).to_i
  if @protocol_name == 'MQIsdp' and @protocol_level == 3
    @version = '3.1.0'
  elsif @protocol_name == 'MQTT' and @protocol_level == 4
    @version = '3.1.1'
  else
    raise ProtocolException.new(
      "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
  if ((@connect_flags & 0x80) >> 7) == 0x01 and buffer.bytesize > 0
    @username = shift_string(buffer)
  end
  if ((@connect_flags & 0x40) >> 6) == 0x01 and buffer.bytesize > 0
    @password = shift_string(buffer)
  end
end

#protocol_versionObject

Deprecated.

Please use #protocol_level instead


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# File 'lib/mqtt/packet.rb', line 569

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 574

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