Fixes #37995 - High memory rendering Arf Report index page (#584)

* Fixes #37995 - High memory rendering Arf Report index page

Avoid using includes() with nested associations and "order by"
together. Otherwise, includes() will use join tables instead
and Rails somehow create many objects and high memory
consumption.

* Update app/controllers/arf_reports_controller.rb

---------

Co-authored-by: Adam Růžička <[email protected]>

app/controllers/arf_reports_controller.rb

@@ -10,9 +10,15 @@ def model_of_controller
   end
 
   def index
+    # Avoid using includes() with nested associations and "order by" together. Otherwise,
+    # includes() will use join tables instead and Rails somehow create many objects and
+    # high memory consumption.
+    @arf_reports_pg = resource_base.search_for(params[:search], :order => params[:order])
+                                   .paginate(:page => params[:page], :per_page => params[:per_page])
+    arf_report_ids = @arf_reports_pg.pluck(:id)
     @arf_reports = resource_base.includes(:policy, :openscap_proxy, :host => %i[policies last_report_object host_statuses])
-                                .search_for(params[:search], :order => params[:order])
-                                .paginate(:page => params[:page], :per_page => params[:per_page])
+                                .where(id: arf_report_ids)
+                                .sort_by { |arf_report| arf_report_ids.index(arf_report.id) }
   end
 
   def show

app/views/arf_reports/_list.html.erb

@@ -56,4 +56,4 @@
     </div>
   </div>
 </div>
-<%= will_paginate_with_info @arf_reports %>
+<%= will_paginate_with_info @arf_reports_pg %>