Class: Skein::Client::RPC

Inherits:
Skein::Connected show all
Defined in:
lib/skein/client/rpc.rb

Constant Summary collapse

EXCHANGE_NAME_DEFAULT =

Constants ============================================================

''.freeze

Instance Attribute Summary

Attributes inherited from Skein::Connected

#channel, #connection, #context, #ident

Instance Method Summary collapse

Methods inherited from Skein::Connected

#lock

Constructor Details

#initialize(exchange_name = nil, routing_key: nil, connection: nil, context: nil) ⇒ RPC

Instance Methods =====================================================



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# File 'lib/skein/client/rpc.rb', line 13

def initialize(exchange_name = nil, routing_key: nil, connection: nil, context: nil)
  super(connection: connection, context: context)

  @rpc_exchange = self.channel.direct(exchange_name || EXCHANGE_NAME_DEFAULT, durable: true)
  @routing_key = routing_key
  @response_queue = self.channel.queue(@ident, durable: true, header: true, auto_delete: true)

  @callback = { }

  @consumer = Skein::Adapter.subscribe(@response_queue, block: false) do |payload, delivery_tag, reply_to|
    self.context.trap do
      response = JSON.load(payload)

      if (callback = @callback.delete(response['id']))
        case (callback)
        when Queue
          callback << response['result']
        when Proc
          callback.call
        end
      end

      self.channel.acknowledge(delivery_tag)
    end
  end
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *args) ⇒ Object 



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# File 'lib/skein/client/rpc.rb', line 47

def method_missing(name, *args)
  name = name.to_s

  blocking = !name.sub!(/!\z/, '')

  message_id = SecureRandom.uuid
  request = JSON.dump(
    method: name,
    params: args,
    id: message_id
  )

  @rpc_exchange.publish(
    request,
    routing_key: @routing_key,
    reply_to: blocking ? @ident : nil,
    content_type: 'application/json',
    message_id: message_id
  )

  if (block_given?)
    @callback[message_id] =
      if (defined?(EventMachine))
        EventMachine.next_tick do
          yield
        end
      else
        lambda do
          yield
        end
      end
  elsif (blocking)
    queue = Queue.new

    @callback[message_id] = queue

    queue.pop
  end
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/skein/client/rpc.rb', line 40

def close
  @consumer and @consumer.cancel
  @consumer = nil

  super
end