Move Producer Client up and inject it

This also explicitly define a finalizer method to return a `proc`
instead of making the client itself callable.

---

Changelog: refactor
Refactoring: moveClass

Author: jvortmann

lib/rdkafka/config.rb

@@ -179,11 +179,55 @@ def producer
       # Set callback to receive delivery reports on config
       Rdkafka::Bindings.rd_kafka_conf_set_dr_msg_cb(config, Rdkafka::Callbacks::DeliveryCallbackFunction)
       # Return producer with Kafka client
-      Rdkafka::Producer.new(native_kafka(config, :rd_kafka_producer)).tap do |producer|
+      Rdkafka::Producer.new(ProducerClient.new(native_kafka(config, :rd_kafka_producer))).tap do |producer|
         opaque.producer = producer
       end
     end
 
+    class ProducerClient
+      def initialize(native)
+        @native = native
+
+        # Start thread to poll client for delivery callbacks
+        @polling_thread = Thread.new do
+          loop do
+            Rdkafka::Bindings.rd_kafka_poll(native, 250)
+            # Exit thread if closing and the poll queue is empty
+            if Thread.current[:closing] && Rdkafka::Bindings.rd_kafka_outq_len(native) == 0
+              break
+            end
+          end
+        end
+        @polling_thread.abort_on_exception = true
+        @polling_thread[:closing] = false
+      end
+
+      def native
+        @native
+      end
+
+      def finalizer
+        ->(_) { close }
+      end
+
+      def closed?
+        @native.nil?
+      end
+
+      def close(object_id=nil)
+        return unless @native
+
+        # Indicate to polling thread that we're closing
+        @polling_thread[:closing] = true
+        # Wait for the polling thread to finish up
+        @polling_thread.join
+
+        Rdkafka::Bindings.rd_kafka_destroy(@native)
+
+        @native = nil
+      end
+    end
+
     # Create an admin instance with this configuration.
     #
     # @raise [ConfigError] When the configuration contains invalid options

lib/rdkafka/producer.rb

@@ -10,52 +10,11 @@ class Producer
     attr_reader :delivery_callback
 
     # @private
-    def initialize(native_kafka)
-      @client = ProducerClient.new(native_kafka)
+    def initialize(client)
+      @client = client
 
       # Makes sure, that the producer gets closed before it gets GCed by Ruby
-      ObjectSpace.define_finalizer(self, @client)
-    end
-
-    class ProducerClient
-      def initialize(native)
-        @native = native
-
-        # Start thread to poll client for delivery callbacks
-        @polling_thread = Thread.new do
-          loop do
-            Rdkafka::Bindings.rd_kafka_poll(native, 250)
-            # Exit thread if closing and the poll queue is empty
-            if Thread.current[:closing] && Rdkafka::Bindings.rd_kafka_outq_len(native) == 0
-              break
-            end
-          end
-        end
-        @polling_thread.abort_on_exception = true
-        @polling_thread[:closing] = false
-      end
-
-      def native
-        @native
-      end
-
-      def closed?
-        @native.nil?
-      end
-
-      def close(object_id=nil)
-        return unless @native
-
-        # Indicate to polling thread that we're closing
-        @polling_thread[:closing] = true
-        # Wait for the polling thread to finish up
-        @polling_thread.join
-
-        Rdkafka::Bindings.rd_kafka_destroy(@native)
-
-        @native = nil
-      end
-      alias call close
+      ObjectSpace.define_finalizer(self, client.finalizer)
     end
 
     # Set a callback that will be called every time a message is successfully produced.