Merge branch 'improve-project-external-issue-trackers' into 'master'

Greatly improve external_issue_tracker performance

See 3d41133d48f6522b8755bb91b804864e8e520871 for all the details. As an aside, this commit contains a set of migrations that will introduce downtime as they add a column with a default value which in turn locks the entire table (at least on PostgreSQL).

See merge request !2498

app/models/project.rb

@@ -468,12 +468,9 @@ class Project < ActiveRecord::Base
     !external_issue_tracker
   end
 
-  def external_issues_trackers
-    services.select(&:issue_tracker?).reject(&:default?)
-  end
-
   def external_issue_tracker
-    @external_issues_tracker ||= external_issues_trackers.find(&:activated?)
+    @external_issue_tracker ||=
+      services.issue_trackers.active.without_defaults.first
   end
 
   def can_have_issues_tracker_id?

app/models/project_services/ci_service.rb

@@ -23,9 +23,7 @@
 # List methods you need to implement to get your CI service
 # working with GitLab Merge Requests
 class CiService < Service
-  def category
-    :ci
-  end
+  default_value_for :category, 'ci'
 
   def valid_token?(token)
     self.respond_to?(:token) && self.token.present? && self.token == token

app/models/project_services/gitlab_issue_tracker_service.rb

@@ -24,9 +24,7 @@ class GitlabIssueTrackerService < IssueTrackerService
 
   prop_accessor :title, :description, :project_url, :issues_url, :new_issue_url
 
-  def default?
-    true
-  end
+  default_value_for :default, true
 
   def to_param
     'gitlab'

app/models/project_services/issue_tracker_service.rb

@@ -23,12 +23,10 @@ class IssueTrackerService < Service
 
   validates :project_url, :issues_url, :new_issue_url, presence: true, if: :activated?
 
-  def category
-    :issue_tracker
-  end
+  default_value_for :category, 'issue_tracker'
 
   def default?
-    false
+    default
   end
 
   def issue_url(iid)

app/models/service.rb

@@ -43,6 +43,9 @@ class Service < ActiveRecord::Base
   validates :project_id, presence: true, unless: Proc.new { |service| service.template? }
 
   scope :visible, -> { where.not(type: ['GitlabIssueTrackerService', 'GitlabCiService']) }
+  scope :issue_trackers, -> { where(category: 'issue_tracker') }
+  scope :active, -> { where(active: true) }
+  scope :without_defaults, -> { where(default: false) }
 
   scope :push_hooks, -> { where(push_events: true, active: true) }
   scope :tag_push_hooks, -> { where(tag_push_events: true, active: true) }
@@ -51,6 +54,8 @@ class Service < ActiveRecord::Base
   scope :note_hooks, -> { where(note_events: true, active: true) }
   scope :build_hooks, -> { where(build_events: true, active: true) }
 
+  default_value_for :category, 'common'
+
   def activated?
     active
   end
@@ -60,7 +65,7 @@ class Service < ActiveRecord::Base
   end
 
   def category
-    :common
+    read_attribute(:category).to_sym
   end
 
   def initialize_properties

db/migrate/20160119111158_add_services_category.rb

+class AddServicesCategory < ActiveRecord::Migration
+  def up
+    add_column :services, :category, :string, default: 'common', null: false
+
+    category = quote_column_name('category')
+    type     = quote_column_name('type')
+
+    execute <<-EOF
+UPDATE services
+SET #{category} = 'issue_tracker'
+WHERE #{type} IN (
+  'CustomIssueTrackerService',
+  'GitlabIssueTrackerService',
+  'IssueTrackerService',
+  'JiraService',
+  'RedmineService'
+);
+EOF
+
+    execute <<-EOF
+UPDATE services
+SET #{category} = 'ci'
+WHERE #{type} IN (
+  'BambooService',
+  'BuildkiteService',
+  'CiService',
+  'DroneCiService',
+  'GitlabCiService',
+  'TeamcityService'
+);
+    EOF
+
+    add_index :services, :category
+  end
+
+  def down
+    remove_column :services, :category
+  end
+end

db/migrate/20160119112418_add_services_default.rb

+class AddServicesDefault < ActiveRecord::Migration
+  def up
+    add_column :services, :default, :boolean, default: false
+
+    default = quote_column_name('default')
+    type    = quote_column_name('type')
+
+    execute <<-EOF
+UPDATE services
+SET #{default} = true
+WHERE #{type} = 'GitlabIssueTrackerService'
+EOF
+
+    add_index :services, :default
+  end
+
+  def down
+    remove_column :services, :default
+  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: 20160113111034) do
+ActiveRecord::Schema.define(version: 20160119112418) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -725,9 +725,9 @@ ActiveRecord::Schema.define(version: 20160113111034) do
     t.string   "type"
     t.string   "title"
     t.integer  "project_id"
-    t.datetime "created_at"
-    t.datetime "updated_at"
-    t.boolean  "active",                default: false, null: false
+    t.datetime "created_at",                                           null: false
+    t.datetime "updated_at",                                           null: false
+    t.boolean  "active",                                               null: false
     t.text     "properties"
     t.boolean  "template",                          default: false
     t.boolean  "push_events",                       default: true
@@ -736,9 +736,13 @@ ActiveRecord::Schema.define(version: 20160113111034) do
     t.boolean  "tag_push_events",                   default: true
     t.boolean  "note_events",                       default: true,     null: false
     t.boolean  "build_events",                      default: false,    null: false
+    t.string   "category",                          default: "common", null: false
+    t.boolean  "default",                           default: false
   end
 
+  add_index "services", ["category"], name: "index_services_on_category", using: :btree
   add_index "services", ["created_at", "id"], name: "index_services_on_created_at_and_id", using: :btree
+  add_index "services", ["default"], name: "index_services_on_default", using: :btree
   add_index "services", ["project_id"], name: "index_services_on_project_id", using: :btree
   add_index "services", ["template"], name: "index_services_on_template", using: :btree