Return cached languages if they've been detected before

2 files changed, 33 insertions, 1 deletions

diff --git a/app/services/projects/detect_repository_languages_service.rb b/app/services/projects/detect_repository_languages_service.rb
index 4a837a4fb6a..b020e4d9088 100644
--- a/app/services/projects/detect_repository_languages_service.rb
+++ b/app/services/projects/detect_repository_languages_service.rb
@@ -2,7 +2,7 @@
 
 module Projects
   class DetectRepositoryLanguagesService < BaseService
-    attr_reader :detected_repository_languages, :programming_languages
+    attr_reader :programming_languages
 
     # rubocop: disable CodeReuse/ActiveRecord
     def execute
@@ -25,6 +25,8 @@ module Projects
           RepositoryLanguage.table_name,
           detection.insertions(matching_programming_languages)
         )
+
+        set_detected_repository_languages
       end
 
       project.repository_languages.reload
@@ -56,5 +58,11 @@ module Projects
       retry
     end
     # rubocop: enable CodeReuse/ActiveRecord
+
+    def set_detected_repository_languages
+      return if project.detected_repository_languages?
+
+      project.update_column(:detected_repository_languages, true)
+    end
   end
 end
diff --git a/app/services/projects/repository_languages_service.rb b/app/services/projects/repository_languages_service.rb
new file mode 100644
index 00000000000..e75851c7da4
--- /dev/null
+++ b/app/services/projects/repository_languages_service.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module Projects
+  class RepositoryLanguagesService < BaseService
+    def execute
+      perform_language_detection unless project.detected_repository_languages?
+      persisted_repository_languages
+    end
+
+    private
+
+    def perform_language_detection
+      if persisted_repository_languages.blank?
+        ::DetectRepositoryLanguagesWorker.perform_async(project.id, current_user.id)
+      else
+        project.update_column(:detected_repository_languages, true)
+      end
+    end
+
+    def persisted_repository_languages
+      project.repository_languages
+    end
+  end
+end