Minimize the number of queries by preloading counts and ancestors

By preloading the count of members, projects and subgroups of a group,
we don't need to query them later.

We also preload the entire hierarchy for a search result and include
the counts so we don't need to query for them again

1 files changed, 17 insertions, 4 deletions

diff --git a/app/serializers/group_child_entity.rb b/app/serializers/group_child_entity.rb
index 8a2624c3d32..91e26272355 100644
--- a/app/serializers/group_child_entity.rb
+++ b/app/serializers/group_child_entity.rb
@@ -60,15 +60,23 @@ class GroupChildEntity < Grape::Entity
   end
 
   def children_count
-    @children_count ||= children_finder.total_count
+    @children_count ||= project_count + subgroup_count
   end
 
   def project_count
-    @project_count ||= children_finder.project_count
+    @project_count ||= if object.respond_to?(:preloaded_project_count)
+                         object.preloaded_project_count
+                       else
+                         children_finder.project_count
+                       end
   end
 
   def subgroup_count
-    @subgroup_count ||= children_finder.subgroup_count
+    @subgroup_count ||= if object.respond_to?(:preloaded_subgroup_count)
+                          object.preloaded_subgroup_count
+                        else
+                          children_finder.subgroup_count
+                        end
   end
 
   def leave_path
@@ -88,6 +96,11 @@ class GroupChildEntity < Grape::Entity
   end
 
   def number_users_with_delimiter
-    number_with_delimiter(object.users.count)
+    member_count = if object.respond_to?(:preloaded_member_count)
+                     object.preloaded_member_count
+                   else
+                     object.users.count
+                   end
+    number_with_delimiter(member_count)
   end
 end