Class: Freddy::Producers::SendAndWaitResponseProducer

Inherits:
Object
  • Object
show all
Defined in:
lib/freddy/producers/send_and_wait_response_producer.rb

Constant Summary collapse

CONTENT_TYPE = 
'application/json'.freeze

Instance Method Summary collapse

Constructor Details

#initialize(channel, logger) ⇒ SendAndWaitResponseProducer

Returns a new instance of SendAndWaitResponseProducer.



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# File 'lib/freddy/producers/send_and_wait_response_producer.rb', line 6

def initialize(channel, logger)
  @logger = logger
  @channel = channel

  @request_manager = RequestManager.new(@logger)

  @exchange = @channel.default_exchange
  @topic_exchange = @channel.topic Freddy::FREDDY_TOPIC_EXCHANGE_NAME

  @channel.on_no_route do |correlation_id|
    @request_manager.no_route(correlation_id)
  end

  @response_queue = @channel.queue("", exclusive: true)

  @response_consumer = Consumers::ResponseConsumer.new(@logger)
  @response_consumer.consume(@channel, @response_queue, &method(:handle_response))
end

Instance Method Details

#handle_response(delivery) ⇒ Object 



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# File 'lib/freddy/producers/send_and_wait_response_producer.rb', line 74

def handle_response(delivery)
  correlation_id = delivery.correlation_id

  if request = @request_manager.delete(correlation_id)
    process_response(request, delivery)
  else
    message = "Got rpc response for correlation_id #{correlation_id} "\
              "but there is no requester"
    @logger.warn message
  end
end

#on_timeout(correlation_id, destination, timeout_in_seconds, trace) ⇒ Object 



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# File 'lib/freddy/producers/send_and_wait_response_producer.rb', line 94

def on_timeout(correlation_id, destination, timeout_in_seconds, trace)
  Proc.new do
    @logger.warn "Request timed out waiting response from #{destination}"\
                 ", correlation id #{correlation_id}"

    @request_manager.delete(correlation_id)
    trace.finish
  end
end

#process_response(request, delivery) ⇒ Object 



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# File 'lib/freddy/producers/send_and_wait_response_producer.rb', line 86

def process_response(request, delivery)
  @logger.debug "Got response for request to #{request[:destination]} "\
                "with correlation_id #{delivery.correlation_id}"
  request[:callback].call(delivery.payload, delivery)
ensure
  request[:trace].finish
end

#produce(destination, payload, timeout_in_seconds:, delete_on_timeout:, **properties) ⇒ Object 



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# File 'lib/freddy/producers/send_and_wait_response_producer.rb', line 25

def produce(destination, payload, timeout_in_seconds:, delete_on_timeout:, **properties)
  span = OpenTracing.start_span("freddy:request:#{destination}",
    child_of: Freddy.trace,
    tags: {
      'component': 'freddy',
      'span.kind': 'client', # RPC
      'payload.type': payload[:type]
    }
  )

  correlation_id = SecureRandom.uuid

  container = SyncResponseContainer.new(
    on_timeout(correlation_id, destination, timeout_in_seconds, span)
  )

  @request_manager.store(correlation_id,
    callback: container,
    trace: span,
    destination: destination
  )

  if delete_on_timeout
    properties[:expiration] = (timeout_in_seconds * 1000).to_i
  end

  properties = properties.merge(
    routing_key: destination, content_type: CONTENT_TYPE,
    correlation_id: correlation_id, reply_to: @response_queue.name,
    mandatory: true, type: 'request'
  )
  OpenTracing.global_tracer.inject(span.context, OpenTracing::FORMAT_TEXT_MAP, TraceCarrier.new(properties))
  json_payload = Payload.dump(payload)

  span.log(
    event: 'Publishing request',
    payload: payload,
    response_queue: @response_queue.name,
    correlation_id: correlation_id
  )

  # Connection adapters handle thread safety for #publish themselves. No
  # need to lock these.
  @topic_exchange.publish json_payload, properties.dup
  @exchange.publish json_payload, properties.dup

  container.wait_for_response(timeout_in_seconds)
end