1 files changed, 72 insertions, 0 deletions
diff --git a/lib/gitlab/import_export/group/tree_saver.rb b/lib/gitlab/import_export/group/tree_saver.rb
new file mode 100644
index 00000000000..d538de33c51
--- /dev/null
+++ b/lib/gitlab/import_export/group/tree_saver.rb
@@ -0,0 +1,72 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module ImportExport
+    module Group
+      class TreeSaver
+        attr_reader :full_path, :shared
+
+        def initialize(group:, current_user:, shared:, params: {})
+          @params = params
+          @current_user = current_user
+          @shared = shared
+          @group = group
+          @full_path = File.join(@shared.export_path, 'tree')
+        end
+
+        def save
+          all_groups = Enumerator.new do |group_ids|
+            groups.each do |group|
+              serialize(group)
+              group_ids << group.id
+            end
+          end
+
+          json_writer.write_relation_array('groups', '_all', all_groups)
+
+          true
+        rescue => e
+          @shared.error(e)
+          false
+        ensure
+          json_writer&.close
+        end
+
+        private
+
+        def groups
+          @groups ||= Gitlab::ObjectHierarchy
+            .new(::Group.where(id: @group.id))
+            .base_and_descendants(with_depth: true)
+            .order_by(:depth)
+        end
+
+        def serialize(group)
+          ImportExport::JSON::StreamingSerializer.new(
+            group,
+            group_tree,
+            json_writer,
+            exportable_path: "groups/#{group.id}"
+          ).execute
+        end
+
+        def group_tree
+          @group_tree ||= Gitlab::ImportExport::Reader.new(
+            shared: @shared,
+            config: group_config
+          ).group_tree
+        end
+
+        def group_config
+          Gitlab::ImportExport::Config.new(
+            config: Gitlab::ImportExport.group_config_file
+          ).to_h
+        end
+
+        def json_writer
+          @json_writer ||= ImportExport::JSON::NdjsonWriter.new(@full_path)
+        end
+      end
+    end
+  end
+end