Class: BBK::App::Dispatcher

Inherits:
Object
  • Object
show all
Defined in:
lib/bbk/app/dispatcher.rb,
lib/bbk/app/dispatcher/route.rb,
lib/bbk/app/dispatcher/result.rb,
lib/bbk/app/dispatcher/message.rb,
lib/bbk/app/dispatcher/message_stream.rb,
lib/bbk/app/dispatcher/queue_stream_strategy.rb,
lib/bbk/app/dispatcher/direct_stream_strategy.rb,
sig/bbk/app/dispatcher.rbs,
sig/bbk/app/dispatcher/route.rbs,
sig/bbk/app/dispatcher/result.rbs,
sig/bbk/app/dispatcher/message.rbs,
sig/bbk/app/dispatcher/message_stream.rbs,
sig/bbk/app/dispatcher/stream_strategy.rbs,
sig/bbk/app/dispatcher/queue_stream_strategy.rbs

Defined Under Namespace

Modules: _Consumer, _IncomingMessage, _Mapping, _Message, _Middleware, _MiddlewareBuilder, _MiddlewareClass, _PoolFactory, _ProcessorsStack, _Publisher, _Result, _StreamStrategy Classes: DirectStreamStrategy, Message, MessageStream, QueueStreamStrategy, Result, Route, StreamStrategyClass

Constant Summary collapse

ANSWER_DOMAIN =

Returns:

  • ('answer') 
'answer'.freeze
DEFAULT_PROTOCOL = 
'default'.freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(observer, pool_size: 3, logger: BBK::App.logger, pool_factory: SimplePoolFactory, stream_strategy: QueueStreamStrategy) ⇒ Dispatcher

Returns a new instance of Dispatcher.

Parameters:

  • (Handler)
  • pool_size: (Integer) (defaults to: 3)
  • logger: (logger) (defaults to: BBK::App.logger)
  • pool_factory: (_PoolFactory) (defaults to: SimplePoolFactory)
  • stream_strategy: (StreamStrategyClass) (defaults to: QueueStreamStrategy) 


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# File 'lib/bbk/app/dispatcher.rb', line 41

def initialize(observer, pool_size: 3, logger: BBK::App.logger, pool_factory: SimplePoolFactory, stream_strategy: QueueStreamStrategy)
  @observer = observer
  @pool_size = pool_size
  logger = logger.respond_to?(:tagged) ? logger : ActiveSupport::TaggedLogging.new(logger)
  @logger = BBK::Utils::ProxyLogger.new(logger, tags: 'Dispatcher')
  @consumers = []
  @publishers = []
  @middlewares = []
  @pool_factory = pool_factory
  @stream_strategy_class = stream_strategy
  @force_quit = false
end

Instance Attribute Details

#consumers ⇒ Array[_Consumer] (readonly)

Returns the value of attribute consumers.

Returns:



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# File 'lib/bbk/app/dispatcher.rb', line 36

def consumers
  @consumers
end

#force_quit ⇒ Boolean

Returns the value of attribute force_quit.

Returns:

  • (Boolean) 


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# File 'lib/bbk/app/dispatcher.rb', line 35

def force_quit
  @force_quit
end

#logger ⇒ logger (readonly)

Returns the value of attribute logger.

Returns:



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# File 'lib/bbk/app/dispatcher.rb', line 36

def logger
  @logger
end

#middlewares ⇒ Array[_MiddlewareBuilder|_MiddlewareClass] (readonly)

Returns the value of attribute middlewares.

Returns:



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# File 'lib/bbk/app/dispatcher.rb', line 36

def middlewares
  @middlewares
end

#observer ⇒ Object (readonly)

Returns the value of attribute observer.



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# File 'lib/bbk/app/dispatcher.rb', line 36

def observer
  @observer
end

#pool_size ⇒ Object

Returns the value of attribute pool_size.



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# File 'lib/bbk/app/dispatcher.rb', line 35

def pool_size
  @pool_size
end

#publishers ⇒ Array[_Publisher] (readonly)

Returns the value of attribute publishers.

Returns:



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# File 'lib/bbk/app/dispatcher.rb', line 36

def publishers
  @publishers
end

Instance Method Details

#build_processing_stack ⇒ _ProcessorsStack

Returns:



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# File 'lib/bbk/app/dispatcher.rb', line 199

def build_processing_stack
  # Оптимизация.Строим стэк только один раз. Могут быть проблемы, но надеюсь что всё будет норм
  # Если какая-то мидлварь НЕ должна сохранять состояние (а случайно сохраняет), пусть
  # реализует метод build и чистит состояние
  @processing_stack ||= begin
    stack = proc{|msg| process_message(msg) }
    middlewares.reverse.reduce(stack) do |stack, middleware|
      if middleware.respond_to?(:build)
        middleware.build(stack)
      else
        middleware.new(stack)
      end
    end
  end
end

#close(timeout = 5) ⇒ void

This method returns an undefined value.

stop dispatcher and wait for termination Чтоб остановить диспетчер надо:

  1. остановить консьюмеры
  2. остановить прием новых сообщений - @stream.close
  3. дождаться обработки всего в очереди или таймаут
  4. остановить потоки
  5. остановить middlewares если они имеют метод stop
  6. остановить паблишеры

Parameters:

  • time (Integer) 


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# File 'lib/bbk/app/dispatcher.rb', line 94

def close(timeout = 5)
  ActiveSupport::Notifications.instrument 'dispatcher.close', dispatcher: self
  consumers.each do |cons|
    begin
      cons.stop
    rescue StandardError => e
      logger.error "Consumer #{cons} stop error: #{e}"
      logger.debug e.backtrace
    end
  end

  @stream_strategy&.stop(timeout)

  consumers.each do |cons|
    begin
      cons.close
    rescue StandardError => e
      logger.error "Consumer #{cons} close error: #{e}"
      logger.debug e.backtrace
    end
  end

  # останавливаем middlewares
  middlewares.each do |m|
    next unless m.respond_to?(:stop)
    m.stop
  rescue StandardError => e
    logger.error "Middleware #{m} stop error: #{e}"
    logger.debug e.backtrace
  end

  publishers.each do |pub|
    begin
      pub.close
    rescue StandardError => e
      logger.error "Publisher #{pub} close error: #{e}"
      logger.debug e.backtrace
    end
  end
end

#execute_message(message) ⇒ Object 



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# File 'lib/bbk/app/dispatcher.rb', line 135

def execute_message(message)
  build_processing_stack.call(message).select do |r|
    r.is_a?(BBK::App::Dispatcher::Result)
  end
end

#find_processor(msg) ⇒ [untyped, _Processor]

Parameters:

Returns:



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# File 'lib/bbk/app/dispatcher.rb', line 187

def find_processor(msg)
  matched, callback = if @observer.respond_to?(:match_message)
    # Новый интерфейс рассчитаный на BBK::Message
    @observer.match_message(msg)
  else
    # старый интерфейс
    @observer.match(msg.headers, msg.payload, msg.delivery_info)
  end
  
  [matched, callback.is_a?(BBK::App::Factory) ? callback.create : callback]
end

#process(message) ⇒ void

This method returns an undefined value.

process one message and sending existed results messages

Parameters:



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# File 'lib/bbk/app/dispatcher.rb', line 142

def process(message)
  results = execute_message(message)
  if message.respond_to?(:nacked?) && message.nacked?
    logger.debug "Ignore sending results: message(#{message.headers[:message_id]}) nacked in processor"
    return
  end
  logger.debug "There are #{results.count} results to send from #{message.headers[:message_id]}..."
  ActiveSupport::Notifications.instrument 'dispatcher.process', msg: message do
    send_results(message, results).value
  end
rescue StandardError => e
  logger.error "Failed processing message: #{e.inspect}"
  # это событие устарело, вместо него надо использовать `dispatcher.process`
  ActiveSupport::Notifications.instrument 'dispatcher.exception', msg: message, exception: e
  message.nack(error: e)
  close if force_quit
end

#process_message(message) ⇒ Array[Result]

Parameters:

Returns:



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# File 'lib/bbk/app/dispatcher.rb', line 162

def process_message(message)
  matched, processor = find_processor(message)
  results = []
  begin
    is_unknown = @observer.instance_variable_get('@default') == processor
    ActiveSupport::Notifications.instrument 'dispatcher.request.process', msg: message,
match: matched, unknown: is_unknown, processor: processor do
      processor.call(message, results: results)
    end
  rescue StandardError => e
    logger.error "Failed processing message in processor: #{e.inspect}. Backrace: #{e.backtrace[0..10]}"
    if processor.respond_to?(:on_error)
      results = processor.on_error(message, e)
    else
      raise
    end
  end
  [results].flatten
rescue StandardError => e
  # это событие устарело, вместо него надо использовать `dispatcher.request.process`
  ActiveSupport::Notifications.instrument 'dispatcher.request.exception', msg: message,
match: matched, processor: processor, exception: e
  raise
end

#publish_result(result) ⇒ Concurrent::Promises::ResolvableFuture

Parameters:

Returns:

  • (Concurrent::Promises::ResolvableFuture) 


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# File 'lib/bbk/app/dispatcher.rb', line 245

def publish_result(result)
  route = result.route
  logger.debug "Publish result to #{route} ..."
  publisher = publishers.find {|pub| pub.protocols.include?(route.scheme) }
  raise "Not found publisher for scheme #{route.scheme}" if publisher.nil?

  # return Concurrent::Promises.resolvable_future
  publisher.publish(result)
end

#register_consumer(consumer) ⇒ void

This method returns an undefined value.

Parameters:



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# File 'lib/bbk/app/dispatcher.rb', line 54

def register_consumer(consumer)
  consumers << consumer
end

#register_middleware(middleware) ⇒ void

This method returns an undefined value.

Parameters:



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# File 'lib/bbk/app/dispatcher.rb', line 64

def register_middleware(middleware)
  middlewares << middleware
end

#register_publisher(publisher) ⇒ void

This method returns an undefined value.

Parameters:



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# File 'lib/bbk/app/dispatcher.rb', line 58

def register_publisher(publisher)
  raise "Publisher support #{DEFAULT_PROTOCOL}" if publisher.protocols.include?(DEFAULT_PROTOCOL)

  publishers << publisher
end

#run ⇒ void

This method returns an undefined value.

Run all consumers and blocks on message processing



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# File 'lib/bbk/app/dispatcher.rb', line 69

def run
  @pool = @pool_factory.call(@pool_size, 10)
  @stream_strategy = @stream_strategy_class.new(@pool, logger: logger)
  ActiveSupport::Notifications.instrument 'dispatcher.run', dispatcher: self

  @stream_strategy.run(consumers) do |msg|
    begin
      logger.tagged(msg.headers[:message_id]) do
        process msg
      end
    rescue StandardError => e
      logger.fatal "E[#{@stream_strategy_class}]: #{e}"
      logger.fatal "E[#{@stream_strategy_class}]: #{e.backtrace.join("\n")}"
    end
  end
end

#send_results(incoming, results) ⇒ void

This method returns an undefined value.

Parameters:

Raises:



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# File 'lib/bbk/app/dispatcher.rb', line 215

def send_results(incoming, results)
  message_id = incoming.headers[:message_id]

  answers, sended_messages = results.partition { _1.route.domain == ANSWER_DOMAIN }
  # allowed only one answer message
  raise InvalidAnswersMessagesCountError.new("Get #{answers.size} on processing message with id=#{message_id}") if answers.size > 1

  answer = answers.first
  Concurrent::Promises.zip_futures(*sended_messages.map do |result|
                                     publish_result(result)
                                   end).then do |_successes|
    incoming.ack(answer: answer)
  end.rescue do |*errors|
    error = errors.compact.first
    ActiveSupport::Notifications.instrument 'dispatcher.request.result_rejected',
                                            msg: incoming, message: error.inspect
    logger.error "[Message#{message_id}] Publish failed: #{error.inspect}"
    incoming.nack(error: error)
    close if force_quit
  rescue StandardError => e
    warn e.backtrace
    warn "[CRITICAL] #{self.class} [#{Process.pid}] failure exiting: #{e.inspect}"
    ActiveSupport::Notifications.instrument 'dispatcher.exception', msg:       incoming,
                                                                    exception: e
    sleep(10)
    exit!(1)
  end
end