1 files changed, 57 insertions, 0 deletions
diff --git a/lib/gitlab/import_export/project/relation_saver.rb b/lib/gitlab/import_export/project/relation_saver.rb
new file mode 100644
index 00000000000..b40827e36f8
--- /dev/null
+++ b/lib/gitlab/import_export/project/relation_saver.rb
@@ -0,0 +1,57 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module ImportExport
+    module Project
+      class RelationSaver
+        def initialize(project:, shared:, relation:)
+          @project = project
+          @relation = relation
+          @shared = shared
+        end
+
+        def save
+          if root_relation?
+            serializer.serialize_root
+          else
+            serializer.serialize_relation(relation_schema)
+          end
+
+          true
+        rescue StandardError => e
+          shared.error(e)
+          false
+        end
+
+        private
+
+        attr_reader :project, :relation, :shared
+
+        def serializer
+          @serializer ||= ::Gitlab::ImportExport::Json::StreamingSerializer.new(
+            project,
+            reader.project_tree,
+            json_writer,
+            exportable_path: 'project'
+          )
+        end
+
+        def root_relation?
+          relation == Projects::ImportExport::RelationExport::ROOT_RELATION
+        end
+
+        def relation_schema
+          reader.project_tree[:include].find { |include| include[relation.to_sym] }
+        end
+
+        def reader
+          @reader ||= ::Gitlab::ImportExport::Reader.new(shared: shared)
+        end
+
+        def json_writer
+          @json_writer ||= ::Gitlab::ImportExport::Json::NdjsonWriter.new(shared.export_path)
+        end
+      end
+    end
+  end
+end