[CLIENT] allow transports to close connections during __rebuild_conne…

…ctions

adds a no-op __close_connections called during __rebuild_connections
this commit also implements this method for manticore transport that marks
all connections as dead and calls Manticore::Client#close for each connection

Closes #241
See: cheald/manticore#39
Related: #245, logstash-plugins/logstash-output-elasticsearch#306

elasticsearch-transport/lib/elasticsearch/transport/transport/base.rb

@@ -96,9 +96,18 @@ def resurrect_dead_connections!
         def __rebuild_connections(arguments={})
           @hosts       = arguments[:hosts]    || []
           @options     = arguments[:options]  || {}
+          __close_connections
           @connections = __build_connections
         end
 
+        # Closes the connections collection.
+        #
+        # @api private
+        #
+        def __close_connections
+          # to be implemented by specific transports
+        end
+
         # Log request and response information.
         #
         # @api private

elasticsearch-transport/lib/elasticsearch/transport/transport/http/manticore.rb

@@ -105,6 +105,16 @@ def __build_connections
               :selector => options[:selector]
           end
 
+          # Closes all connections by marking them as dead
+          # and closing the underlying HttpClient instances
+          #
+          # @return [Connections::Collection]
+          #
+          def __close_connections
+            @connections.each {|c| c.dead! }
+            @connections.all.each {|c| c.connection.close }
+          end
+
           # Returns an array of implementation specific connection errors.
           #
           # @return [Array]

elasticsearch-transport/test/unit/transport_base_test.rb

@@ -473,6 +473,11 @@ def initialize(*); end
       @transport = DummyTransport.new
     end
 
+    should "close connections" do
+      @transport.expects(:__close_connections)
+      @transport.__rebuild_connections :hosts => ['foo']
+    end
+
     should "should replace the connections" do
       assert_equal [], @transport.connections
       @transport.__rebuild_connections :hosts => ['foo', 'bar']

elasticsearch-transport/test/unit/transport_manticore_test.rb

@@ -26,6 +26,19 @@ class Elasticsearch::Transport::Transport::HTTP::ManticoreTest < Test::Unit::Tes
         assert_instance_of ::Manticore::Client,   @transport.connections.first.connection
       end
 
+      should "implement __close_connections" do
+        assert_equal 1, @transport.connections.size
+        @transport.__close_connections
+        assert_equal 0, @transport.connections.size
+      end
+
+      should "prevent requests after __close_connections" do
+        @transport.__close_connections
+        assert_raises ::Manticore::ClientStoppedException do
+          @transport.perform_request 'GET', '/'
+        end
+      end
+
       should "perform the request" do
         @transport.connections.first.connection.expects(:get).returns(stub_everything)
         @transport.perform_request 'GET', '/'