Merge branch 'move-notification-service-calls-to-sidekiq' into 'master'

Move NotificationService calls to Sidekiq

Closes #43106

See merge request gitlab-org/gitlab-ce!18535

9 files changed, 59 insertions, 45 deletions

diff --git a/app/services/issues/close_service.rb b/app/services/issues/close_service.rb
index fee5bc38f7b..4a99367c575 100644
--- a/app/services/issues/close_service.rb
+++ b/app/services/issues/close_service.rb
@@ -26,7 +26,7 @@ module Issues
         issue.update(closed_by: current_user)
         event_service.close_issue(issue, current_user)
         create_note(issue, commit) if system_note
-        notification_service.close_issue(issue, current_user) if notifications
+        notification_service.async.close_issue(issue, current_user) if notifications
         todo_service.close_issue(issue, current_user)
         execute_hooks(issue, 'close')
         invalidate_cache_counts(issue, users: issue.assignees)
diff --git a/app/services/issues/move_service.rb b/app/services/issues/move_service.rb
index 7140890d201..78e79344c99 100644
--- a/app/services/issues/move_service.rb
+++ b/app/services/issues/move_service.rb
@@ -139,7 +139,7 @@ module Issues
     end
 
     def notify_participants
-      notification_service.issue_moved(@old_issue, @new_issue, @current_user)
+      notification_service.async.issue_moved(@old_issue, @new_issue, @current_user)
     end
   end
 end
diff --git a/app/services/issues/reopen_service.rb b/app/services/issues/reopen_service.rb
index 62b4b4b6a1e..02224f3357a 100644
--- a/app/services/issues/reopen_service.rb
+++ b/app/services/issues/reopen_service.rb
@@ -6,7 +6,7 @@ module Issues
       if issue.reopen
         event_service.reopen_issue(issue, current_user)
         create_note(issue, 'reopened')
-        notification_service.reopen_issue(issue, current_user)
+        notification_service.async.reopen_issue(issue, current_user)
         execute_hooks(issue, 'reopen')
         invalidate_cache_counts(issue, users: issue.assignees)
         issue.update_project_counter_caches
diff --git a/app/services/issues/update_service.rb b/app/services/issues/update_service.rb
index 1374f10c586..1000e1842b6 100644
--- a/app/services/issues/update_service.rb
+++ b/app/services/issues/update_service.rb
@@ -30,7 +30,7 @@ module Issues
 
       if issue.assignees != old_assignees
         create_assignee_note(issue, old_assignees)
-        notification_service.reassigned_issue(issue, current_user, old_assignees)
+        notification_service.async.reassigned_issue(issue, current_user, old_assignees)
         todo_service.reassigned_issue(issue, current_user, old_assignees)
       end
 
@@ -41,13 +41,13 @@ module Issues
       added_labels = issue.labels - old_labels
 
       if added_labels.present?
-        notification_service.relabeled_issue(issue, added_labels, current_user)
+        notification_service.async.relabeled_issue(issue, added_labels, current_user)
       end
 
       added_mentions = issue.mentioned_users - old_mentioned_users
 
       if added_mentions.present?
-        notification_service.new_mentions_in_issue(issue, added_mentions, current_user)
+        notification_service.async.new_mentions_in_issue(issue, added_mentions, current_user)
       end
     end
 
diff --git a/app/services/merge_requests/close_service.rb b/app/services/merge_requests/close_service.rb
index f727ec002e7..db701c1145d 100644
--- a/app/services/merge_requests/close_service.rb
+++ b/app/services/merge_requests/close_service.rb
@@ -10,7 +10,7 @@ module MergeRequests
       if merge_request.close
         create_event(merge_request)
         create_note(merge_request)
-        notification_service.close_mr(merge_request, current_user)
+        notification_service.async.close_mr(merge_request, current_user)
         todo_service.close_merge_request(merge_request, current_user)
         execute_hooks(merge_request, 'close')
         invalidate_cache_counts(merge_request, users: merge_request.assignees)
diff --git a/app/services/merge_requests/reopen_service.rb b/app/services/merge_requests/reopen_service.rb
index 120677a7149..8f1c95ac1b7 100644
--- a/app/services/merge_requests/reopen_service.rb
+++ b/app/services/merge_requests/reopen_service.rb
@@ -6,7 +6,7 @@ module MergeRequests
       if merge_request.reopen
         create_event(merge_request)
         create_note(merge_request, 'reopened')
-        notification_service.reopen_mr(merge_request, current_user)
+        notification_service.async.reopen_mr(merge_request, current_user)
         execute_hooks(merge_request, 'reopen')
         merge_request.reload_diff(current_user)
         merge_request.mark_as_unchecked
diff --git a/app/services/merge_requests/resolved_discussion_notification_service.rb b/app/services/merge_requests/resolved_discussion_notification_service.rb
index 3a09350c847..66a0cbc81d4 100644
--- a/app/services/merge_requests/resolved_discussion_notification_service.rb
+++ b/app/services/merge_requests/resolved_discussion_notification_service.rb
@@ -4,7 +4,7 @@ module MergeRequests
       return unless merge_request.discussions_resolved?
 
       SystemNoteService.resolve_all_discussions(merge_request, project, current_user)
-      notification_service.resolve_all_discussions(merge_request, current_user)
+      notification_service.async.resolve_all_discussions(merge_request, current_user)
     end
   end
 end
diff --git a/app/services/merge_requests/update_service.rb b/app/services/merge_requests/update_service.rb
index 8a40ad88182..7350725e223 100644
--- a/app/services/merge_requests/update_service.rb
+++ b/app/services/merge_requests/update_service.rb
@@ -21,6 +21,7 @@ module MergeRequests
       update(merge_request)
     end
 
+    # rubocop:disable Metrics/AbcSize
     def handle_changes(merge_request, options)
       old_associations = options.fetch(:old_associations, {})
       old_labels = old_associations.fetch(:labels, [])
@@ -42,8 +43,11 @@ module MergeRequests
       end
 
       if merge_request.previous_changes.include?('assignee_id')
+        old_assignee_id = merge_request.previous_changes['assignee_id'].first
+        old_assignee = User.find(old_assignee_id) if old_assignee_id
+
         create_assignee_note(merge_request)
-        notification_service.reassigned_merge_request(merge_request, current_user)
+        notification_service.async.reassigned_merge_request(merge_request, current_user, old_assignee)
         todo_service.reassigned_merge_request(merge_request, current_user)
       end
 
@@ -54,7 +58,7 @@ module MergeRequests
 
       added_labels = merge_request.labels - old_labels
       if added_labels.present?
-        notification_service.relabeled_merge_request(
+        notification_service.async.relabeled_merge_request(
           merge_request,
           added_labels,
           current_user
@@ -63,13 +67,14 @@ module MergeRequests
 
       added_mentions = merge_request.mentioned_users - old_mentioned_users
       if added_mentions.present?
-        notification_service.new_mentions_in_merge_request(
+        notification_service.async.new_mentions_in_merge_request(
           merge_request,
           added_mentions,
           current_user
         )
       end
     end
+    # rubocop:enable Metrics/AbcSize
 
     def merge_from_quick_action(merge_request)
       last_diff_sha = params.delete(:merge)
diff --git a/app/services/notification_service.rb b/app/services/notification_service.rb
index 274161df946..55a1735e54b 100644
--- a/app/services/notification_service.rb
+++ b/app/services/notification_service.rb
@@ -7,7 +7,32 @@
 # Ex.
 #   NotificationService.new.new_issue(issue, current_user)
 #
+# When calculating the recipients of a notification is expensive (for instance,
+# in the new issue case), `#async` will make that calculation happen in Sidekiq
+# instead:
+#
+#   NotificationService.new.async.new_issue(issue, current_user)
+#
 class NotificationService
+  class Async
+    attr_reader :parent
+    delegate :respond_to_missing, to: :parent
+
+    def initialize(parent)
+      @parent = parent
+    end
+
+    def method_missing(meth, *args)
+      return super unless parent.respond_to?(meth)
+
+      MailScheduler::NotificationServiceWorker.perform_async(meth.to_s, *args)
+    end
+  end
+
+  def async
+    @async ||= Async.new(self)
+  end
+
   # Always notify user about ssh key added
   # only if ssh key is not deploy key
   #
@@ -142,8 +167,23 @@ class NotificationService
   #  * merge_request assignee if their notification level is not Disabled
   #  * users with custom level checked with "reassign merge request"
   #
-  def reassigned_merge_request(merge_request, current_user)
-    reassign_resource_email(merge_request, current_user, :reassigned_merge_request_email)
+  def reassigned_merge_request(merge_request, current_user, previous_assignee)
+    recipients = NotificationRecipientService.build_recipients(
+      merge_request,
+      current_user,
+      action: "reassign",
+      previous_assignee: previous_assignee
+    )
+
+    recipients.each do |recipient|
+      mailer.reassigned_merge_request_email(
+        recipient.user.id,
+        merge_request.id,
+        previous_assignee&.id,
+        current_user.id,
+        recipient.reason
+      ).deliver_later
+    end
   end
 
   # When we add labels to a merge request we should send an email to:
@@ -421,29 +461,6 @@ class NotificationService
     end
   end
 
-  def reassign_resource_email(target, current_user, method)
-    previous_assignee_id = previous_record(target, 'assignee_id')
-    previous_assignee = User.find_by(id: previous_assignee_id) if previous_assignee_id
-
-    recipients = NotificationRecipientService.build_recipients(
-      target,
-      current_user,
-      action: "reassign",
-      previous_assignee: previous_assignee
-    )
-
-    recipients.each do |recipient|
-      mailer.send(
-        method,
-        recipient.user.id,
-        target.id,
-        previous_assignee_id,
-        current_user.id,
-        recipient.reason
-      ).deliver_later
-    end
-  end
-
   def relabeled_resource_email(target, labels, current_user, method)
     recipients = labels.flat_map { |l| l.subscribers(target.project) }.uniq
     recipients = notifiable_users(
@@ -471,14 +488,6 @@ class NotificationService
     Notify
   end
 
-  def previous_record(object, attribute)
-    return unless object && attribute
-
-    if object.previous_changes.include?(attribute)
-      object.previous_changes[attribute].first
-    end
-  end
-
   private
 
   def recipients_for_pages_domain(domain)