Merge branch '65988-optimize-snippet-listings' into 'master'

Optimize queries for snippet listings

See merge request gitlab-org/gitlab-ce!32576

12 files changed, 97 insertions, 71 deletions

diff --git a/app/controllers/concerns/issuable_collections.rb b/app/controllers/concerns/issuable_collections.rb
index 8ea77b994de..88044cf7557 100644
--- a/app/controllers/concerns/issuable_collections.rb
+++ b/app/controllers/concerns/issuable_collections.rb
@@ -2,6 +2,7 @@
 
 module IssuableCollections
   extend ActiveSupport::Concern
+  include PaginatedCollection
   include SortingHelper
   include SortingPreference
   include Gitlab::IssuableMetadata
@@ -17,8 +18,11 @@ module IssuableCollections
   def set_issuables_index
     @issuables = issuables_collection
 
-    set_pagination
-    return if redirect_out_of_range(@total_pages)
+    unless pagination_disabled?
+      set_pagination
+
+      return if redirect_out_of_range(@issuables, @total_pages)
+    end
 
     if params[:label_name].present? && @project
       labels_params = { project_id: @project.id, title: params[:label_name] }
@@ -38,12 +42,10 @@ module IssuableCollections
   end
 
   def set_pagination
-    return if pagination_disabled?
-
     @issuables          = @issuables.page(params[:page])
     @issuables          = per_page_for_relative_position if params[:sort] == 'relative_position'
     @issuable_meta_data = issuable_meta_data(@issuables, collection_type, current_user)
-    @total_pages        = issuable_page_count
+    @total_pages        = issuable_page_count(@issuables)
   end
   # rubocop:enable Gitlab/ModuleWithInstanceVariables
 
@@ -57,20 +59,8 @@ module IssuableCollections
   end
   # rubocop: enable CodeReuse/ActiveRecord
 
-  def redirect_out_of_range(total_pages)
-    return false if total_pages.nil? || total_pages.zero?
-
-    out_of_range = @issuables.current_page > total_pages # rubocop:disable Gitlab/ModuleWithInstanceVariables
-
-    if out_of_range
-      redirect_to(url_for(safe_params.merge(page: total_pages, only_path: true)))
-    end
-
-    out_of_range
-  end
-
-  def issuable_page_count
-    page_count_for_relation(@issuables, finder.row_count) # rubocop:disable Gitlab/ModuleWithInstanceVariables
+  def issuable_page_count(relation)
+    page_count_for_relation(relation, finder.row_count)
   end
 
   def page_count_for_relation(relation, row_count)
diff --git a/app/controllers/concerns/paginated_collection.rb b/app/controllers/concerns/paginated_collection.rb
new file mode 100644
index 00000000000..be84215a9e2
--- /dev/null
+++ b/app/controllers/concerns/paginated_collection.rb
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+module PaginatedCollection
+  extend ActiveSupport::Concern
+
+  private
+
+  def redirect_out_of_range(collection, total_pages = collection.total_pages)
+    return false if total_pages.zero?
+
+    out_of_range = collection.current_page > total_pages
+
+    if out_of_range
+      redirect_to(url_for(safe_params.merge(page: total_pages, only_path: true)))
+    end
+
+    out_of_range
+  end
+end
diff --git a/app/controllers/dashboard/snippets_controller.rb b/app/controllers/dashboard/snippets_controller.rb
index 161c22046f9..6feade3df03 100644
--- a/app/controllers/dashboard/snippets_controller.rb
+++ b/app/controllers/dashboard/snippets_controller.rb
@@ -1,14 +1,19 @@
 # frozen_string_literal: true
 
 class Dashboard::SnippetsController < Dashboard::ApplicationController
+  include PaginatedCollection
+  include Gitlab::NoteableMetadata
+
   skip_cross_project_access_check :index
 
   def index
-    @snippets = SnippetsFinder.new(
-      current_user,
-      author: current_user,
-      scope: params[:scope]
-    ).execute
-    @snippets = @snippets.page(params[:page])
+    @snippets = SnippetsFinder.new(current_user, author: current_user, scope: params[:scope])
+      .execute
+      .page(params[:page])
+      .inc_author
+
+    return if redirect_out_of_range(@snippets)
+
+    @noteable_meta_data = noteable_meta_data(@snippets, 'Snippet')
   end
 end
diff --git a/app/controllers/dashboard/todos_controller.rb b/app/controllers/dashboard/todos_controller.rb
index 8f6fcb362d2..940d1482611 100644
--- a/app/controllers/dashboard/todos_controller.rb
+++ b/app/controllers/dashboard/todos_controller.rb
@@ -2,6 +2,7 @@
 
 class Dashboard::TodosController < Dashboard::ApplicationController
   include ActionView::Helpers::NumberHelper
+  include PaginatedCollection
 
   before_action :authorize_read_project!, only: :index
   before_action :authorize_read_group!, only: :index
@@ -12,7 +13,7 @@ class Dashboard::TodosController < Dashboard::ApplicationController
     @todos = @todos.page(params[:page])
     @todos = @todos.with_entity_associations
 
-    return if redirect_out_of_range(@todos)
+    return if redirect_out_of_range(@todos, todos_page_count(@todos))
   end
 
   def destroy
@@ -82,28 +83,15 @@ class Dashboard::TodosController < Dashboard::ApplicationController
     }
   end
 
-  def todo_params
-    params.permit(:action_id, :author_id, :project_id, :type, :sort, :state, :group_id)
-  end
-
-  # rubocop: disable CodeReuse/ActiveRecord
-  def redirect_out_of_range(todos)
-    total_pages =
-      if todo_params.except(:sort, :page).empty?
-        (current_user.todos_pending_count.to_f / todos.limit_value).ceil
-      else
-        todos.total_pages
-      end
-
-    return false if total_pages.zero?
-
-    out_of_range = todos.current_page > total_pages
-
-    if out_of_range
-      redirect_to url_for(safe_params.merge(page: total_pages, only_path: true))
+  def todos_page_count(todos)
+    if todo_params.except(:sort, :page).empty? # rubocop: disable CodeReuse/ActiveRecord
+      (current_user.todos_pending_count.to_f / todos.limit_value).ceil
+    else
+      todos.total_pages
     end
+  end
 
-    out_of_range
+  def todo_params
+    params.permit(:action_id, :author_id, :project_id, :type, :sort, :state, :group_id)
   end
-  # rubocop: enable CodeReuse/ActiveRecord
 end
diff --git a/app/controllers/explore/snippets_controller.rb b/app/controllers/explore/snippets_controller.rb
index 76ed142c939..d4c6aae2ca8 100644
--- a/app/controllers/explore/snippets_controller.rb
+++ b/app/controllers/explore/snippets_controller.rb
@@ -1,8 +1,17 @@
 # frozen_string_literal: true
 
 class Explore::SnippetsController < Explore::ApplicationController
+  include PaginatedCollection
+  include Gitlab::NoteableMetadata
+
   def index
-    @snippets = SnippetsFinder.new(current_user).execute
-    @snippets = @snippets.page(params[:page])
+    @snippets = SnippetsFinder.new(current_user)
+      .execute
+      .page(params[:page])
+      .inc_author
+
+    return if redirect_out_of_range(@snippets)
+
+    @noteable_meta_data = noteable_meta_data(@snippets, 'Snippet')
   end
 end
diff --git a/app/controllers/projects/snippets_controller.rb b/app/controllers/projects/snippets_controller.rb
index 59f948959d6..dbd11c8ddc8 100644
--- a/app/controllers/projects/snippets_controller.rb
+++ b/app/controllers/projects/snippets_controller.rb
@@ -6,6 +6,8 @@ class Projects::SnippetsController < Projects::ApplicationController
   include SpammableActions
   include SnippetsActions
   include RendersBlob
+  include PaginatedCollection
+  include Gitlab::NoteableMetadata
 
   skip_before_action :verify_authenticity_token,
     if: -> { action_name == 'show' && js_request? }
@@ -28,15 +30,14 @@ class Projects::SnippetsController < Projects::ApplicationController
   respond_to :html
 
   def index
-    @snippets = SnippetsFinder.new(
-      current_user,
-      project: @project,
-      scope: params[:scope]
-    ).execute
-    @snippets = @snippets.page(params[:page])
-    if @snippets.out_of_range? && @snippets.total_pages != 0
-      redirect_to project_snippets_path(@project, page: @snippets.total_pages)
-    end
+    @snippets = SnippetsFinder.new(current_user, project: @project, scope: params[:scope])
+      .execute
+      .page(params[:page])
+      .inc_author
+
+    return if redirect_out_of_range(@snippets)
+
+    @noteable_meta_data = noteable_meta_data(@snippets, 'Snippet')
   end
 
   def new
diff --git a/app/controllers/snippets_controller.rb b/app/controllers/snippets_controller.rb
index 869655e9550..5805d068e21 100644
--- a/app/controllers/snippets_controller.rb
+++ b/app/controllers/snippets_controller.rb
@@ -7,6 +7,8 @@ class SnippetsController < ApplicationController
   include SnippetsActions
   include RendersBlob
   include PreviewMarkdown
+  include PaginatedCollection
+  include Gitlab::NoteableMetadata
 
   skip_before_action :verify_authenticity_token,
     if: -> { action_name == 'show' && js_request? }
@@ -32,7 +34,13 @@ class SnippetsController < ApplicationController
       @user = UserFinder.new(params[:username]).find_by_username!
 
       @snippets = SnippetsFinder.new(current_user, author: @user, scope: params[:scope])
-        .execute.page(params[:page])
+        .execute
+        .page(params[:page])
+        .inc_author
+
+      return if redirect_out_of_range(@snippets)
+
+      @noteable_meta_data = noteable_meta_data(@snippets, 'Snippet')
 
       render 'index'
     else
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 91e0efcf45f..e38d4073de3 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -4,6 +4,7 @@ class UsersController < ApplicationController
   include RoutableActions
   include RendersMemberAccess
   include ControllerWithCrossProjectAccessCheck
+  include Gitlab::NoteableMetadata
 
   requires_cross_project_access show: false,
                                 groups: false,
@@ -165,11 +166,12 @@ class UsersController < ApplicationController
   end
 
   def load_snippets
-    @snippets = SnippetsFinder.new(
-      current_user,
-      author: user,
-      scope: params[:scope]
-    ).execute.page(params[:page])
+    @snippets = SnippetsFinder.new(current_user, author: user, scope: params[:scope])
+      .execute
+      .page(params[:page])
+      .inc_author
+
+    @noteable_meta_data = noteable_meta_data(@snippets, 'Snippet')
   end
 
   def build_canonical_path(user)
diff --git a/app/models/concerns/noteable.rb b/app/models/concerns/noteable.rb
index 6a44bc7c401..b3e4df730b4 100644
--- a/app/models/concerns/noteable.rb
+++ b/app/models/concerns/noteable.rb
@@ -3,6 +3,10 @@
 module Noteable
   extend ActiveSupport::Concern
 
+  # This object is used to gather noteable meta data for list displays
+  # avoiding n+1 queries and improving performance.
+  NoteableMeta = Struct.new(:user_notes_count)
+
   class_methods do
     # `Noteable` class names that support replying to individual notes.
     def replyable_types
diff --git a/app/models/snippet.rb b/app/models/snippet.rb
index 00931457344..b2fca65b9e0 100644
--- a/app/models/snippet.rb
+++ b/app/models/snippet.rb
@@ -55,6 +55,7 @@ class Snippet < ApplicationRecord
   scope :are_public, -> { where(visibility_level: Snippet::PUBLIC) }
   scope :public_and_internal, -> { where(visibility_level: [Snippet::PUBLIC, Snippet::INTERNAL]) }
   scope :fresh, -> { order("created_at DESC") }
+  scope :inc_author, -> { includes(:author) }
   scope :inc_relations_for_view, -> { includes(author: :status) }
 
   participant :author
diff --git a/app/views/shared/snippets/_list.html.haml b/app/views/shared/snippets/_list.html.haml
index 5d2152eb411..766f48fff3d 100644
--- a/app/views/shared/snippets/_list.html.haml
+++ b/app/views/shared/snippets/_list.html.haml
@@ -1,12 +1,11 @@
 - remote = local_assigns.fetch(:remote, false)
 - link_project = local_assigns.fetch(:link_project, false)
 
-- if @snippets.exists?
+- if @snippets.to_a.empty?
+  .nothing-here-block= s_("SnippetsEmptyState|No snippets found")
+- else
   .snippets-list-holder
     %ul.content-list
       = render partial: 'shared/snippets/snippet', collection: @snippets, locals: { link_project: link_project }
 
     = paginate @snippets, theme: 'gitlab', remote: remote
-
-- else
-  .nothing-here-block= s_("SnippetsEmptyState|No snippets found")
diff --git a/app/views/shared/snippets/_snippet.html.haml b/app/views/shared/snippets/_snippet.html.haml
index 42af97bc6af..0ef626868a2 100644
--- a/app/views/shared/snippets/_snippet.html.haml
+++ b/app/views/shared/snippets/_snippet.html.haml
@@ -1,4 +1,5 @@
 - link_project = local_assigns.fetch(:link_project, false)
+- notes_count = @noteable_meta_data[snippet.id].user_notes_count
 
 %li.snippet-row
   = image_tag avatar_icon_for_user(snippet.author), class: "avatar s40 d-none d-sm-block", alt: ''
@@ -12,10 +13,9 @@
 
     %ul.controls
       %li
-        - note_count = snippet.notes.user.count
-        = link_to reliable_snippet_path(snippet, anchor: 'notes'), class: ('no-comments' if note_count.zero?) do
+        = link_to reliable_snippet_path(snippet, anchor: 'notes'), class: ('no-comments' if notes_count.zero?) do
           = icon('comments')
-          = note_count
+          = notes_count
       %li
         %span.sr-only
           = visibility_level_label(snippet.visibility_level)