Module: AMQP::Client

Includes:
EM::Deferrable, RightSupport::Log::Mixin
Defined in:
lib/right_amqp/amqp/client.rb

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.connect(opts = {}) ⇒ Object 



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# File 'lib/right_amqp/amqp/client.rb', line 290

def self.connect opts = {}
  opts = AMQP.settings.merge(opts)
  EM.connect opts[:host], opts[:port], self, opts
end

.included(base) ⇒ Object 



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# File 'lib/right_amqp/amqp/client.rb', line 76

def self.included(base)
  base.extend(RightSupport::Log::Mixin::ClassMethods)
end

Instance Method Details

#add_channel(mq) ⇒ Object 



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# File 'lib/right_amqp/amqp/client.rb', line 177

def add_channel mq
  (@_channel_mutex ||= Mutex.new).synchronize do
    channels[ key = (channels.keys.max || 0) + 1 ] = mq
    key
  end
end

#channels ⇒ Object 



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# File 'lib/right_amqp/amqp/client.rb', line 184

def channels
  @channels ||= {}
end

#close(&on_disconnect) ⇒ Object

:stopdoc: def send_data data

log 'send_data', data
super

end :startdoc:



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# File 'lib/right_amqp/amqp/client.rb', line 229

def close &on_disconnect
  @heartbeat_timer.cancel if @heartbeat_timer
  @heartbeat_timer = nil
  if on_disconnect
    @closing = true
    @on_disconnect = proc{
      on_disconnect.call
      @closing = false
    }
  end

  callback{ |c|
    if c.channels.any?
      c.channels.each do |ch, mq|
        mq.close
      end
    else
      send Protocol::Connection::Close.new(:reply_code => 200,
                                           :reply_text => 'Goodbye',
                                           :class_id => 0,
                                           :method_id => 0)
    end
  }
end

#connected? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/right_amqp/amqp/client.rb', line 166

def connected?
  @connected
end

#connection_completed ⇒ Object 



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# File 'lib/right_amqp/amqp/client.rb', line 92

def connection_completed
  start_tls if @settings[:ssl]
  log 'connected'
  # @on_disconnect = proc{ raise Error, 'Disconnected from server' }
  unless @closing
    @on_disconnect = method(:disconnected)
    @reconnecting = false
  end

  @connected = true
  logger.debug("[amqp] Connected to broker #{@settings[:identity]}")
  @connection_status.call(:connected) if @connection_status

  @buf = Buffer.new
  send_data HEADER
  send_data [1, 1, VERSION_MAJOR, VERSION_MINOR].pack('C4')

  if heartbeat = @settings[:heartbeat]
    init_heartbeat if (@settings[:heartbeat] = heartbeat.to_i) > 0
  end
end

#connection_status(&blk) ⇒ Object 



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# File 'lib/right_amqp/amqp/client.rb', line 295

def connection_status &blk
  @connection_status = blk
end

#failed ⇒ Object 



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# File 'lib/right_amqp/amqp/client.rb', line 299

def failed
  @connection_status.call(:failed) if @connection_status
  @has_failed = true
  close_connection
end

#init_heartbeat ⇒ Object 



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# File 'lib/right_amqp/amqp/client.rb', line 114

def init_heartbeat
  # Randomly offset start of heartbeat timer to help separate heartbeat
  # activity when there are multiple broker connections active
  EM.add_timer(rand(@settings[:heartbeat])) do
    begin
      # While connected, a heartbeat or some other data is expected to be received from
      # the broker at least every 2 x :heartbeat seconds, otherwise the connection is
      # assumed to be broken and therefore is closed to cause an automatic reconnect.
      # While connected, this client will send a heartbeat every :heartbeat
      # seconds regardless of any other send activity. The RabbitMQ broker will behave
      # similarly and drop the connection if it does not receive a heartbeat or other
      # data in time.
      logger.info("[amqp] Initializing heartbeat for broker #{@settings[:identity]} to #{@settings[:heartbeat]} sec")

      timeout_factor = 2
      @heartbeat_timer.cancel if @heartbeat_timer
      @heartbeat_timer = EM::PeriodicTimer.new(@settings[:heartbeat]) do
        begin
          if connected?
            now = Time.now
            if @last_data_received.nil?
              # This is something of an anomaly; not clear how this condition is reached
              logger.info("[amqp] Reconnecting to broker #{@settings[:identity]} due to heartbeat timeout " +
                          "with no data having been received")
              close_connection # which results in an unbind and an automatic reconnect
            elsif @last_data_received < (now - (@settings[:heartbeat] * timeout_factor))
              data_received = (now - @last_data_received).to_i
              heartbeat_received = (now - @last_heartbeat_received).to_i if @last_heartbeat_received
              heartbeat_sent = (now - @last_heartbeat_sent).to_i if @last_heartbeat_sent
              logger.info("[amqp] Reconnecting to broker #{@settings[:identity]} due to heartbeat timeout: " +
                          "last data received #{data_received.inspect} sec ago, " +
                          "last heartbeat received #{heartbeat_received.inspect} sec ago, " +
                          "last heartbeat sent #{heartbeat_sent.inspect} sec ago")
              close_connection # which results in an unbind and an automatic reconnect
            else
              logger.debug("[amqp] Sending heartbeat to broker #{@settings[:identity]}")
              send AMQP::Frame::Heartbeat.new, :channel => 0
              @last_heartbeat_sent = Time.now
            end
          else
            logger.debug("[amqp] Skipping heartbeat check for broker #{@settings[:identity]} because disconnected")
          end
        rescue Exception => e
          logger.error("[amqp] Failed heartbeat check (#{e})\n" + e.backtrace.join("\n"))
        end
      end
    rescue Exception => e
      logger.error("[amqp] Failed heartbeat initialization (#{e})\n" + e.backtrace.join("\n"))
    end
  end
end

#initialize(opts = {}) ⇒ Object 



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# File 'lib/right_amqp/amqp/client.rb', line 80

def initialize opts = {}
  @settings = opts
  extend AMQP.client

  @on_disconnect ||= proc{ @connection_status.call(:failed) if @connection_status }

  timeout @settings[:timeout] if @settings[:timeout]
  errback{ @on_disconnect.call } unless @reconnecting

  @connected = false
end

#process_frame(frame) ⇒ Object 



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# File 'lib/right_amqp/amqp/client.rb', line 208

def process_frame frame
  # this is a stub meant to be
  # replaced by the module passed into initialize
end

#receive_data(data) ⇒ Object

Catch exceptions that would otherwise cause EM to stop or be in a bad state if a top level EM error handler was setup. Instead close the connection and leave EM alone. Don’t log an error if the environment variable IGNORE_AMQP_FAILURES is set (used in the enroll script)



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# File 'lib/right_amqp/amqp/client.rb', line 193

def receive_data data
  begin
    # log 'receive_data', data
    @buf << data

    while frame = Frame.parse(@buf)
      log 'receive', frame
      process_frame frame
    end
  rescue Exception => e
    logger.exception("[amqp] Failed processing frame, closing connection", e, :trace) unless ENV['IGNORE_AMQP_FAILURES']
    failed
  end
end

#reconnect(force = false) ⇒ Object 



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# File 'lib/right_amqp/amqp/client.rb', line 254

def reconnect force = false
  if @reconnecting and not force
    # Wait after first reconnect attempt and in between each subsequent attempt
    EM.add_timer(@settings[:reconnect_interval] || 5) { reconnect(true) }
    return
  end

  unless @reconnecting
    @deferred_status = nil
    initialize(@settings)

    mqs = @channels
    @channels = {}
    mqs.each{ |_,mq| mq.reset } if mqs

    @reconnecting = true

    again = @settings[:reconnect_delay]
    again = again.call if again.is_a?(Proc)
    if again.is_a?(Numeric)
      # Wait before making initial reconnect attempt
      EM.add_timer(again) { reconnect(true) }
      return
    elsif ![nil, true].include?(again)
      raise ::AMQP::Error, "Could not interpret :reconnect_delay => #{again.inspect}; expected nil, true, or Numeric"
    end
  end

  log 'reconnecting'
  logger.info("[amqp] Attempting to reconnect to broker #{@settings[:identity]}")
  EM.reconnect(@settings[:host], @settings[:port], self)
rescue Exception => e
  logger.exception("[amqp] Failed to reconnect", e, :trace)
  failed
end

#send(data, opts = {}) ⇒ Object 



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# File 'lib/right_amqp/amqp/client.rb', line 213

def send data, opts = {}
  channel = opts[:channel] ||= 0
  data = data.to_frame(channel) unless data.is_a? Frame
  data.channel = channel

  log 'send', data
  send_data data.to_s
end

#unbind ⇒ Object 



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# File 'lib/right_amqp/amqp/client.rb', line 170

def unbind
  log 'disconnected'
  @connected = false
  logger.debug("[amqp] Disconnected from broker #{@settings[:identity]}")
  EM.next_tick{ @on_disconnect.call }
end