Add latest changes from gitlab-org/gitlab@master

1 files changed, 45 insertions, 0 deletions

diff --git a/lib/gitlab/utils/lazy_attributes.rb b/lib/gitlab/utils/lazy_attributes.rb
new file mode 100644
index 00000000000..79f3a7dcb53
--- /dev/null
+++ b/lib/gitlab/utils/lazy_attributes.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Utils
+    module LazyAttributes
+      extend ActiveSupport::Concern
+      include Gitlab::Utils::StrongMemoize
+
+      class_methods do
+        def lazy_attr_reader(*one_or_more_names, type: nil)
+          names = Array.wrap(one_or_more_names)
+          names.each { |name| define_lazy_reader(name, type: type) }
+        end
+
+        def lazy_attr_accessor(*one_or_more_names, type: nil)
+          names = Array.wrap(one_or_more_names)
+          names.each do |name|
+            define_lazy_reader(name, type: type)
+            define_lazy_writer(name)
+          end
+        end
+
+        private
+
+        def define_lazy_reader(name, type:)
+          define_method(name) do
+            strong_memoize("#{name}_lazy_loaded") do
+              value = instance_variable_get("@#{name}")
+              value = value.call if value.respond_to?(:call)
+              value = nil if type && !value.is_a?(type)
+              value
+            end
+          end
+        end
+
+        def define_lazy_writer(name)
+          define_method("#{name}=") do |value|
+            clear_memoization("#{name}_lazy_loaded")
+            instance_variable_set("@#{name}", value)
+          end
+        end
+      end
+    end
+  end
+end