Class: Vx::Lib::Consumer::Rpc::RpcClient

Inherits:
Object
  • Object
show all
Defined in:
lib/vx/lib/consumer/rpc.rb

Constant Summary collapse

REP = 
"rep".freeze
REQ = 
"req".freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(consumer) ⇒ RpcClient

Returns a new instance of RpcClient.



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# File 'lib/vx/lib/consumer/rpc.rb', line 71

def initialize(consumer)
  @consumer = consumer
  @consumed = false
  @await    = {}
  @mutex    = Mutex.new
  @wakeup   = Mutex.new
end

Instance Attribute Details

#consumer ⇒ Object (readonly)

Returns the value of attribute consumer.



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# File 'lib/vx/lib/consumer/rpc.rb', line 69

def consumer
  @consumer
end

Instance Method Details

#call(ns, method, params, options = {}) ⇒ Object 



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# File 'lib/vx/lib/consumer/rpc.rb', line 126

def call(ns, method, params, options = {})
  timeout     = options[:timeout] || 3
  routing_key = options[:routing_key] || "vx.rpc.#{ns}".freeze
  call_id     = SecureRandom.uuid
  cond        = ConditionVariable.new
  result      = nil

  message = {
    method: method.to_s,
    params: params,
    id:     call_id
  }

  with_queue do |q|

    consumer.session.with_pub_channel do |ch|
      exch = ch.exchange RPC_EXCHANGE_NAME

      instrumentation = {
        payload:     message,
        rpc:         REQ,
        exchange:    exch.name,
        consumer:    consumer.params.consumer_name,
        properties:  { routing_key: routing_key, correlation_id: call_id },
        channel:     ch.id
      }

      @mutex.synchronize { @await[call_id] = cond }

      consumer.with_middlewares :pub, instrumentation do
        consumer.instrument(:process_publishing, instrumentation) do
          exch.publish(
            message.to_json,
            routing_key:    routing_key,
            correlation_id: call_id,
            reply_to:       q.name,
            content_type:   JSON_CONTENT_TYPE
          )
        end
      end

      @wakeup.synchronize{
        cond.wait(@wakeup, timeout)
      }
      @mutex.synchronize do
        _, payload = @await.delete(call_id)
        if payload
          result = payload[RPC_PAYLOAD_RESULT]
        else
          nil
        end
      end
    end
  end

  result

end

#cancel ⇒ Object 



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# File 'lib/vx/lib/consumer/rpc.rb', line 194

def cancel
  instrumentation = {
    consumer: consumer.params.consumer_name,
    rpc:      'consume'
  }

  consumer.instrument('cancel_consumer', instrumentation)

  if subscriber?
    @subscriber.cancel
    @subscriber = nil
    @consumed   = false
  end
end

#consume ⇒ Object 



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# File 'lib/vx/lib/consumer/rpc.rb', line 79

def consume
  return if @consumed

  ch = consumer.session.conn.create_channel
  consumer.session.assign_error_handlers_to_channel(ch)

  @q = ch.queue(RPC_EXCHANGE_NAME, exclusive: true)

  @subscriber =
    @q.subscribe do |delivery_info, properties, payload|
      handle_delivery ch, properties, payload
    end
  @consumed = true
end

#handle_delivery(ch, properties, payload) ⇒ Object 



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# File 'lib/vx/lib/consumer/rpc.rb', line 94

def handle_delivery(ch, properties, payload)

  if payload
    payload = ::JSON.parse(payload)
  end

  instrumentation = {
    consumer:   consumer.params.consumer_name,
    queue:      @q.name,
    rpc:        REP,
    channel:    ch.id,
    payload:    payload,
    properties: properties
  }

  consumer.with_middlewares :sub, instrumentation do
    consumer.instrument(:start_processing, instrumentation)
    consumer.instrument(:process, instrumentation) do
      call_id = properties[:correlation_id]
      c = @mutex.synchronize{ @await.delete(call_id) }
      if c
        @mutex.synchronize do
          @await[call_id] = [properties, payload]
        end
        @wakeup.synchronize do
          c.signal
        end
      end
    end
  end
end

#subscriber? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/vx/lib/consumer/rpc.rb', line 190

def subscriber?
  !!@subscriber
end

#with_queue {|@q| ... } ⇒ Object

Yields:

  • (@q) 


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# File 'lib/vx/lib/consumer/rpc.rb', line 185

def with_queue
  consume
  yield @q
end