Class: Majordomo::Broker

Inherits:
Object
  • Object
show all
Defined in:
lib/majordomo/broker.rb,
lib/majordomo/broker/worker.rb,
lib/majordomo/broker/service.rb

Defined Under Namespace

Classes: Service, Worker

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(bind = 'tcp://*:5555', context = ZMQ::Context.new) ⇒ Broker

Returns a new instance of Broker.



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# File 'lib/majordomo/broker.rb', line 9

def initialize(bind = 'tcp://*:5555', context = ZMQ::Context.new)
  @context      = context
  @socket       = @context.socket(ZMQ::ROUTER)
  @poller       = ZMQ::Poller.new
  @services     = {}
  @workers      = {}
  @waiting      = []
  @heartbeat_at = Time.now + 0.001 * HEARTBEAT_INTERVAL

  @socket.bind(bind)
  @poller.register(@socket, ZMQ::POLLIN)
  trap(:INT) { exit }
  at_exit { destroy }
end

Instance Attribute Details

#services ⇒ Object

Returns the value of attribute services.



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# File 'lib/majordomo/broker.rb', line 7

def services
  @services
end

#socket ⇒ Object

Returns the value of attribute socket.



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# File 'lib/majordomo/broker.rb', line 7

def socket
  @socket
end

#waiting ⇒ Object

Returns the value of attribute waiting.



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# File 'lib/majordomo/broker.rb', line 7

def waiting
  @waiting
end

#workers ⇒ Object

Returns the value of attribute workers.



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# File 'lib/majordomo/broker.rb', line 7

def workers
  @workers
end

Instance Method Details

#bind(endpoint) ⇒ Object 



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# File 'lib/majordomo/broker.rb', line 57

def bind(endpoint)
  @socket.bind(endpoint)
end

#destroy ⇒ Object 



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# File 'lib/majordomo/broker.rb', line 52

def destroy
  @socket.close
  @context.terminate
end

#mediate ⇒ Object 



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# File 'lib/majordomo/broker.rb', line 24

def mediate
  loop do
    items = @poller.poll(HEARTBEAT_INTERVAL)

    if items > 0
      @socket.recv_strings(message = [])
      sender = message.shift
      message.shift #empty
      header = message.shift
      case header
        when CLIENT
          message_client(sender, message)
        when WORKER
          message_worker(sender, message)
      end
    end

    if Time.now > @heartbeat_at
      purge
      waiting.each do |worker|
        worker.send_message(HEARTBEAT)
      end
      @heartbeat_at = Time.now + 0.001 * HEARTBEAT_INTERVAL
      puts "Heartbeat #{waiting.count}"
    end
  end
end

#message_client(sender, message) ⇒ Object 



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# File 'lib/majordomo/broker.rb', line 108

def message_client(sender, message)
  service_name = message.shift
  service      = Service.require(self, service_name)

  message.unshift nil
  message.unshift sender

  service.requests << message
  service.dispatch
end

#message_worker(sender, message) ⇒ Object 



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# File 'lib/majordomo/broker.rb', line 61

def message_worker(sender, message)
  command      = message.shift
  identity     = sender.unpack('H*').first
  worker_ready = !!@workers[identity]

  worker = Worker.require(self, sender)

  case command
    when READY
      if worker_ready
        worker.delete(true)
      else
        service        = message.shift
        worker.service = Service.require(self, service)
        @waiting << worker
        worker.service.waiting << worker
        worker.service.workers += 1
        worker.expires_at      = Time.now + 0.001 * HEARTBEAT_EXPIRY
        worker.service.dispatch
      end
    when REPLY
      if worker_ready
        client = message.shift
        message.shift
        message.unshift(worker.service.name)
        message.unshift(CLIENT)
        message.unshift(nil)
        message.unshift(client)
        @socket.send_strings(message)
      else
        worker.delete(true)
      end
    when HEARTBEAT
      if worker_ready
        if @waiting.any?
          @waiting.delete(worker)
          @waiting << worker
        end
        worker.expires_at = Time.now + 0.001 * HEARTBEAT_EXPIRY
      else
        worker.delete(true)
      end
    when DISCONNECT
      worker.delete(false)
  end
end

#purge ⇒ Object 



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# File 'lib/majordomo/broker.rb', line 119

def purge
  waiting.each do |worker|
    worker.delete(false) if Time.now > worker.expires_at
  end
end