1 files changed, 32 insertions, 0 deletions
diff --git a/app/models/preloaders/group_root_ancestor_preloader.rb b/app/models/preloaders/group_root_ancestor_preloader.rb
new file mode 100644
index 00000000000..3ca713d9635
--- /dev/null
+++ b/app/models/preloaders/group_root_ancestor_preloader.rb
@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+module Preloaders
+  class GroupRootAncestorPreloader
+    def initialize(groups, root_ancestor_preloads = [])
+      @groups = groups
+      @root_ancestor_preloads = root_ancestor_preloads
+    end
+
+    def execute
+      return unless ::Feature.enabled?(:use_traversal_ids, default_enabled: :yaml)
+
+      # type == 'Group' condition located on subquery to prevent a filter in the query
+      root_query = Namespace.joins("INNER JOIN (#{join_sql}) as root_query ON root_query.root_id = namespaces.id")
+                        .select('namespaces.*, root_query.id as source_id')
+
+      root_query = root_query.preload(*@root_ancestor_preloads) if @root_ancestor_preloads.any?
+
+      root_ancestors_by_id = root_query.group_by(&:source_id)
+
+      @groups.each do |group|
+        group.root_ancestor = root_ancestors_by_id[group.id].first
+      end
+    end
+
+    private
+
+    def join_sql
+      Group.select('id, traversal_ids[1] as root_id').where(id: @groups.map(&:id)).to_sql
+    end
+  end
+end