Fix log messages and its conditions

lib/fluent/event_router.rb

@@ -207,10 +207,14 @@ def optimized_filter_stream(tag, es)
 
         def optimizable?
           return @optimizable unless @optimizable.nil?
-          @optimizable = if filters_having_filter_stream.empty?
+          fs_filters = filters_having_filter_stream
+          @optimizable = if fs_filters.empty?
                            true
                          else
-                           $log.info "Filtering works with worse performance, because #{filters_having_filter_stream.map(&:class)} uses `#filter_stream` method."
+                           # skip log message when filter is only 1, because its performace is same as non optimized chain.
+                           if @filters.size > 1 && fs_filters.size >= 1
+                             $log.info "disable filter chain optimization because #{fs_filters.map(&:class)} uses `#filter_stream` method."
+                           end
                            false
                          end
         end

lib/fluent/plugin/storage_local.rb

@@ -56,7 +56,8 @@ def configure(conf)
         elsif @path
           # ok
         else # @_plugin_id_configured is true
-          raise NotImplementedError, "implement this feature later with system_config"
+          log.warn "path for <storage> is not specified. Using on-memory store temporarily, but will use file store after support global storage path"
+          @on_memory = true
           ## TODO: get process-wide directory for plugin storage, and generate path for this plugin storage instance
           # path = 
         end

test/test_event_router.rb

@@ -307,7 +307,7 @@ def filter_with_time(tag, time, record); end
 
         e = OneEventStream.new(@now, @record)
         assert_rr do
-          mock($log).info("Filtering works with worse performance, because #{[filter_stream].map(&:class)} uses `#filter_stream` method.")
+          mock($log).info("disable filter chain optimization because #{[filter_stream].map(&:class)} uses `#filter_stream` method.")
           mock(filter_stream).filter_stream('test', is_a(OneEventStream)) { e }
           mock(filter).filter_stream('test', is_a(OneEventStream)) { e }
           mock(filter_with_time).filter_stream('test', is_a(OneEventStream)) { e }