Enable Gitaly ref caching for SearchController

As we noticed in
https://gitlab.com/gitlab-org/gitlab-ce/issues/56627#note_185828742,
clicking on the "Issues" tab often requests the same reference in
rendering Markdown.

app/controllers/application_controller.rb

@@ -516,4 +516,10 @@ class ApplicationController < ActionController::Base
   def sentry_context
     Gitlab::Sentry.context(current_user)
   end
+
+  def allow_gitaly_ref_name_caching
+    ::Gitlab::GitalyClient.allow_ref_name_caching do
+      yield
+    end
+  end
 end

app/controllers/projects/application_controller.rb

@@ -87,10 +87,4 @@ class Projects::ApplicationController < ApplicationController
   def check_issues_available!
     return render_404 unless @project.feature_available?(:issues, current_user)
   end
-
-  def allow_gitaly_ref_name_caching
-    ::Gitlab::GitalyClient.allow_ref_name_caching do
-      yield
-    end
-  end
 end

app/controllers/search_controller.rb

@@ -5,6 +5,8 @@ class SearchController < ApplicationController
   include SearchHelper
   include RendersCommits
+  around_action :allow_gitaly_ref_name_caching
+
   skip_before_action :authenticate_user!
   requires_cross_project_access if: -> do
     search_term_present = params[:search].present? || params[:term].present?

changelogs/unreleased/sh-add-gitaly-ref-caching-search-controller.yml

+---
+title: Enable Gitaly ref caching for SearchController
+merge_request: 30105
+author:
+type: performance

spec/controllers/search_controller_spec.rb

@@ -17,6 +17,10 @@ describe SearchController do
     set(:project) { create(:project, :public, :repository, :wiki_repo) }
+    before do
+      expect(::Gitlab::GitalyClient).to receive(:allow_ref_name_caching).and_call_original
+    end
+
     subject { get(:show, params: { project_id: project.id, scope: scope, search: 'merge' }) }
     where(:partial, :scope) do