Class: MqttRails::ConnectionHelper

Inherits:
Object
  • Object
show all
Defined in:
lib/mqtt_rails/connection_helper.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(host, port, ssl, ssl_context, ack_timeout) ⇒ ConnectionHelper

Returns a new instance of ConnectionHelper.



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# File 'lib/mqtt_rails/connection_helper.rb', line 22

def initialize(host, port, ssl, ssl_context, ack_timeout)
  @cs          = MQTT_CS_DISCONNECT
  @socket      = nil
  @host        = host
  @port        = port
  @ssl         = ssl
  @ssl_context = ssl_context
  @ack_timeout = ack_timeout
  @sender      = Sender.new(ack_timeout)
end

Instance Attribute Details

#sender ⇒ Object

Returns the value of attribute sender.



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# File 'lib/mqtt_rails/connection_helper.rb', line 20

def sender
  @sender
end

Instance Method Details

#check_keep_alive(persistent, keep_alive) ⇒ Object 



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# File 'lib/mqtt_rails/connection_helper.rb', line 156

def check_keep_alive(persistent, keep_alive)
  now = Time.now
  last_packet_received_at = @handler.last_packet_received_at
  # send a PINGREQ only if we don't already wait for a PINGRESP
  if persistent && should_send_ping?(now, keep_alive, last_packet_received_at)
    Rails.logger.info("Checking if server is still alive...")
    @sender.send_pingreq
  end
  disconnect_timeout_at = last_packet_received_at + (keep_alive * 1.1).ceil
  if disconnect_timeout_at <= now
    Rails.logger.info("No activity is over timeout, disconnecting from #{@host}.")
    @cs = MQTT_CS_DISCONNECT
  end
  @cs
end

#clean_start(host, port) ⇒ Object 



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# File 'lib/mqtt_rails/connection_helper.rb', line 105

def clean_start(host, port)
  self.host = host
  self.port = port
  unless @socket.nil?
    @socket.close unless @socket.closed?
    @socket = nil
  end
end

#config_socket ⇒ Object 



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# File 'lib/mqtt_rails/connection_helper.rb', line 80

def config_socket
  Rails.logger.info("Attempt to connect to host: #{@host}...")
  begin
    tcp_socket = TCPSocket.new(@host, @port)
    if @ssl
      encrypted_socket(tcp_socket, @ssl_context)
    else
      @socket = tcp_socket
    end
  rescue StandardError
    Rails.logger.warn("Could not open a socket with #{@host} on port #{@port}.")
  end
end

#do_connect(reconnection = false) ⇒ Object 



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# File 'lib/mqtt_rails/connection_helper.rb', line 37

def do_connect(reconnection=false)
  @cs = MQTT_CS_NEW
  @handler.socket = @socket
  # Waiting a Connack packet for "ack_timeout" second from the remote
  connect_timeout = Time.now + @ack_timeout
  while (Time.now <= connect_timeout) && !is_connected? do
    @cs = @handler.receive_packet
  end
  unless is_connected?
    Rails.logger.warn("Connection failed. Couldn't recieve a Connack packet from: #{@host}.")
    raise Exception.new("Connection failed. Check log for more details.") unless reconnection
  end
  @cs
end

#do_disconnect(publisher, explicit, mqtt_thread) ⇒ Object 



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# File 'lib/mqtt_rails/connection_helper.rb', line 56

def do_disconnect(publisher, explicit, mqtt_thread)
  Rails.logger.info("Disconnecting from #{@host}.")
  if explicit
    explicit_disconnect(publisher, mqtt_thread)
  end
  @socket.close unless @socket.nil? || @socket.closed?
  @socket = nil
end

#encrypted_socket(tcp_socket, ssl_context) ⇒ Object 



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# File 'lib/mqtt_rails/connection_helper.rb', line 94

def encrypted_socket(tcp_socket, ssl_context)
  unless ssl_context.nil?
    @socket = OpenSSL::SSL::SSLSocket.new(tcp_socket, ssl_context)
    @socket.sync_close = true
    @socket.connect
  else
    Rails.logger.error("The SSL context was found as nil while the socket's opening.")
    raise Exception
  end
end

#explicit_disconnect(publisher, mqtt_thread) ⇒ Object 



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# File 'lib/mqtt_rails/connection_helper.rb', line 65

def explicit_disconnect(publisher, mqtt_thread)
  @sender.flush_waiting_packet(false)
  send_disconnect
  mqtt_thread.kill if mqtt_thread && mqtt_thread.alive?
  publisher.flush_publisher unless publisher.nil?
end

#handler=(handler) ⇒ Object 



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# File 'lib/mqtt_rails/connection_helper.rb', line 33

def handler=(handler)
  @handler = handler
end

#host=(host) ⇒ Object 



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# File 'lib/mqtt_rails/connection_helper.rb', line 114

def host=(host)
  if host.nil? || host == ""
    Rails.logger.error("The host was found as nil while the connection setup.")
    raise ArgumentError
  else
    @host = host
  end
end

#is_connected? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mqtt_rails/connection_helper.rb', line 52

def is_connected?
  @cs == MQTT_CS_CONNECTED
end

#port=(port) ⇒ Object 



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# File 'lib/mqtt_rails/connection_helper.rb', line 123

def port=(port)
  if port.to_i <= 0
    Rails.logger.error("The port value is invalid (<= 0). Could not setup the connection.")
    raise ArgumentError
  else
    @port = port
  end
end

#send_connect(session_params) ⇒ Object 



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# File 'lib/mqtt_rails/connection_helper.rb', line 132

def send_connect(session_params)
  setup_connection
  packet = MqttRails::Packet::Connect.new(session_params)
  @handler.clean_session = session_params[:clean_session]
  @sender.send_packet(packet)
  MQTT_ERR_SUCCESS
end

#send_disconnect ⇒ Object 



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# File 'lib/mqtt_rails/connection_helper.rb', line 140

def send_disconnect
  packet = MqttRails::Packet::Disconnect.new
  @sender.send_packet(packet)
  MQTT_ERR_SUCCESS
end

#setup_connection ⇒ Object 



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# File 'lib/mqtt_rails/connection_helper.rb', line 72

def setup_connection
  clean_start(@host, @port)
  config_socket
  unless @socket.nil?
    @sender.socket = @socket
  end
end

#should_send_ping?(now, keep_alive, last_packet_received_at) ⇒ Boolean

Would return ‘true’ if ping requset should be sent and ‘nil’ if not

Returns:

  • (Boolean) 


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# File 'lib/mqtt_rails/connection_helper.rb', line 147

def should_send_ping?(now, keep_alive, last_packet_received_at)
  last_pingreq_sent_at = @sender.last_pingreq_sent_at
  last_pingresp_received_at = @handler.last_pingresp_received_at
  if !last_pingreq_sent_at || (last_pingresp_received_at && (last_pingreq_sent_at <= last_pingresp_received_at))
    next_pingreq_at = [@sender.last_packet_sent_at, last_packet_received_at].min + (keep_alive * 0.7).ceil
    return next_pingreq_at <= now
  end
end