Add preload in issues controllerccr/43034_issues_controller_100_queries

5 files changed, 65 insertions, 9 deletions

diff --git a/app/controllers/boards/issues_controller.rb b/app/controllers/boards/issues_controller.rb
index 4f3d737e3ce..55e2b49d003 100644
--- a/app/controllers/boards/issues_controller.rb
+++ b/app/controllers/boards/issues_controller.rb
@@ -18,14 +18,18 @@ module Boards
       list_service = Boards::Issues::ListService.new(board_parent, current_user, filter_params)
       issues = list_service.execute
       issues = issues.page(params[:page]).per(params[:per] || 20).without_count
-      make_sure_position_is_set(issues) if Gitlab::Database.read_write?
-      issues = issues.preload(:project,
-                              :milestone,
+      make_sure_position_is_set(issues)
+      issues = issues.preload(:milestone,
                               :assignees,
+                              project: [
+                                  :route,
+                                  {
+                                      namespace: [:route]
+                                  }
+                              ],
                               labels: [:priorities],
                               notes: [:award_emoji, :author]
                              )
-
       render_issues(issues, list_service.metadata)
     end
     # rubocop: enable CodeReuse/ActiveRecord
@@ -61,6 +65,8 @@ module Boards
     end
 
     def make_sure_position_is_set(issues)
+      return unless Gitlab::Database.read_write?
+
       issues.each do |issue|
         issue.move_to_end && issue.save unless issue.relative_position
       end
diff --git a/app/models/board.rb b/app/models/board.rb
index a137863456c..b060bc42618 100644
--- a/app/models/board.rb
+++ b/app/models/board.rb
@@ -32,4 +32,8 @@ class Board < ActiveRecord::Base
   def scoped?
     false
   end
+
+  def self.preload_label_and_board(lists)
+    lists.preload(:label, :board)
+  end
 end
diff --git a/app/services/boards/lists/list_service.rb b/app/services/boards/lists/list_service.rb
index e10eb52e041..001d42ed6c6 100644
--- a/app/services/boards/lists/list_service.rb
+++ b/app/services/boards/lists/list_service.rb
@@ -6,7 +6,9 @@ module Boards
       def execute(board)
         board.lists.create(list_type: :backlog) unless board.lists.backlog.exists?
 
-        board.lists
+        lists = board.lists
+
+        Board.preload_label_and_board(lists)
       end
     end
   end
diff --git a/changelogs/unreleased/ccr-43034_issues_controller_100_queries.yml b/changelogs/unreleased/ccr-43034_issues_controller_100_queries.yml
new file mode 100644
index 00000000000..d92c0e74c07
--- /dev/null
+++ b/changelogs/unreleased/ccr-43034_issues_controller_100_queries.yml
@@ -0,0 +1,5 @@
+---
+title: Add preload for routes and namespaces for issues controller.
+merge_request: 21651
+author:
+type: performance
diff --git a/spec/controllers/boards/issues_controller_spec.rb b/spec/controllers/boards/issues_controller_spec.rb
index d98e6ff0df8..a859290c228 100644
--- a/spec/controllers/boards/issues_controller_spec.rb
+++ b/spec/controllers/boards/issues_controller_spec.rb
@@ -3,6 +3,9 @@ require 'spec_helper'
 describe Boards::IssuesController do
   let(:project) { create(:project) }
   let(:board)   { create(:board, project: project) }
+  let(:group) { create(:group, :private, projects: [project]) }
+  let(:group_board) { create(:board, group: group) }
+  let(:sub_group_1) { create(:group, :private, parent: group) }
   let(:user)    { create(:user) }
   let(:guest)   { create(:user) }
 
@@ -11,9 +14,11 @@ describe Boards::IssuesController do
 
   let!(:list1) { create(:list, board: board, label: planning, position: 0) }
   let!(:list2) { create(:list, board: board, label: development, position: 1) }
+  let!(:list3) { create(:list, board: group_board, label: development, position: 2) }
 
   before do
     project.add_maintainer(user)
+    group.add_maintainer(user)
     project.add_guest(guest)
   end
 
@@ -56,6 +61,37 @@ describe Boards::IssuesController do
 
           expect { list_issues(user: user, board: board, list: list2) }.not_to exceed_query_limit(control_count)
         end
+
+        it 'avoids N+1 database queries when adding a project', :request_store do
+          create(:labeled_issue, project: project, labels: [development])
+          control_count = ActiveRecord::QueryRecorder.new { list_issues(user: user, board: group_board, list: list3) }.count
+
+          2.times do
+            p = create(:project, group: group)
+            create(:labeled_issue, project: p, labels: [development])
+          end
+
+          project_2 = create(:project, group: group)
+          create(:labeled_issue, project: project_2, labels: [development], assignees: [johndoe])
+
+          expect { list_issues(user: user, board: group_board, list: list3) }.not_to exceed_query_limit(control_count)
+        end
+
+        it 'avoids N+1 database queries when adding a subgroup, project, and issue', :nested_groups do
+          create(:project, group: sub_group_1)
+          create(:labeled_issue, project: project, labels: [development])
+          control_count = ActiveRecord::QueryRecorder.new { list_issues(user: user, board: group_board, list: list3) }.count
+          project_2 = create(:project, group: group)
+
+          2.times do
+            p = create(:project, group: sub_group_1)
+            create(:labeled_issue, project: p, labels: [development])
+          end
+
+          create(:labeled_issue, project: project_2, labels: [development], assignees: [johndoe])
+
+          expect { list_issues(user: user, board: group_board, list: list3) }.not_to exceed_query_limit(control_count)
+        end
       end
 
       context 'with invalid list id' do
@@ -102,12 +138,15 @@ describe Boards::IssuesController do
       sign_in(user)
 
       params = {
-        namespace_id: project.namespace.to_param,
-        project_id: project,
-        board_id: board.to_param,
-        list_id: list.try(:to_param)
+          board_id: board.to_param,
+          list_id: list.try(:to_param)
       }
 
+      unless board.try(:parent)&.is_a?(Group)
+        params[:namespace_id] = project.namespace.to_param
+        params[:project_id] = project
+      end
+
       get :index, params.compact
     end
   end