Merge branch 'fix/speed-up-group-milestone-show' into 'master'

Speed up group milestones show page

See merge request !6457

Former-commit-id: 3f059257

CHANGELOG

 Please view this file on the master branch, on stable branches it's out of date.
-v 8.12.0 (unreleased)
+v 8.13.0 (unreleased)
+  - Speed-up group milestones show page
+v 8.12.0
   - Update the rouge gem to 2.0.6, which adds highlighting support for JSX, Prometheus, and others. !6251
   - Only check :can_resolve permission if the note is resolvable
   - Bump fog-aws to v0.11.0 to support ap-south-1 region

app/models/global_milestone.rb

@@ -8,7 +8,8 @@ class GlobalMilestone
     milestones = milestones.group_by(&:title)
     milestones.map do |title, milestones|
-      new(title, milestones)
+      milestones_relation = Milestone.where(id: milestones.map(&:id))
+      new(title, milestones_relation)
     end
   end
@@ -31,7 +32,7 @@ class GlobalMilestone
   end
   def projects
-    @projects ||= Project.for_milestones(milestones.map(&:id))
+    @projects ||= Project.for_milestones(milestones.select(:id))
   end
   def state
@@ -53,19 +54,19 @@ class GlobalMilestone
   end
   def issues
-    @issues ||= Issue.of_milestones(milestones.map(&:id)).includes(:project)
+    @issues ||= Issue.of_milestones(milestones.select(:id)).includes(:project, :assignee, :labels)
   end
   def merge_requests
-    @merge_requests ||= MergeRequest.of_milestones(milestones.map(&:id)).includes(:target_project)
+    @merge_requests ||= MergeRequest.of_milestones(milestones.select(:id)).includes(:target_project, :assignee, :labels)
   end
   def participants
-    @participants ||= milestones.map(&:participants).flatten.compact.uniq
+    @participants ||= milestones.includes(:participants).map(&:participants).flatten.compact.uniq
   end
   def labels
-    @labels ||= GlobalLabel.build_collection(milestones.map(&:labels).flatten)
+    @labels ||= GlobalLabel.build_collection(milestones.includes(:labels).map(&:labels).flatten)
                            .sort_by!(&:title)
   end

db/migrate/20160920160832_add_index_to_labels_title.rb

+class AddIndexToLabelsTitle < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def change
+    add_concurrent_index :labels, :title
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
-ActiveRecord::Schema.define(version: 20160915042921) do
+ActiveRecord::Schema.define(version: 20160920160832) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -521,6 +521,7 @@ ActiveRecord::Schema.define(version: 20160915042921) do
   add_index "labels", ["priority"], name: "index_labels_on_priority", using: :btree
   add_index "labels", ["project_id"], name: "index_labels_on_project_id", using: :btree
+  add_index "labels", ["title"], name: "index_labels_on_title", using: :btree
   create_table "lfs_objects", force: :cascade do |t|
     t.string   "oid",                  null: false

spec/models/global_milestone_spec.rb

@@ -50,8 +50,9 @@ describe GlobalMilestone, models: true do
           milestone1_project2,
           milestone1_project3,
         ]
-      @global_milestone = GlobalMilestone.new(milestone1_project1.title, milestones)
+      milestones_relation = Milestone.where(id: milestones.map(&:id))
+      @global_milestone = GlobalMilestone.new(milestone1_project1.title, milestones_relation)
     end
     it 'has exactly one group milestone' do
@@ -67,7 +68,7 @@ describe GlobalMilestone, models: true do
     let(:milestone) { create(:milestone, title: "git / test", project: project1) }
     it 'strips out slashes and spaces' do
-      global_milestone = GlobalMilestone.new(milestone.title, [milestone])
+      global_milestone = GlobalMilestone.new(milestone.title, Milestone.where(id: milestone.id))
       expect(global_milestone.safe_title).to eq('git-test')
     end