Refactored code to reduce number of database queries (#960)

app/controllers/admins_controller.rb

@@ -292,11 +292,11 @@ class AdminsController < ApplicationController
   private
 
   def find_user
-    @user = User.where(uid: params[:user_uid]).includes(:roles).first
+    @user = User.find_by(uid: params[:user_uid])
   end
 
   def find_deleted_user
-    @user = User.deleted.where(uid: params[:user_uid]).includes(:roles).first
+    @user = User.deleted.find_by(uid: params[:user_uid])
   end
 
   # Verifies that admin is an administrator of the user in the action

app/controllers/application_controller.rb

@@ -29,7 +29,7 @@ class ApplicationController < ActionController::Base
 
   # Retrieves the current user.
   def current_user
-    @current_user ||= User.where(id: session[:user_id]).includes(:roles).first
+    @current_user ||= User.includes(:roles, :main_room).find_by(id: session[:user_id])
 
     if Rails.configuration.loadbalanced_configuration
       if @current_user && !@current_user.has_role?(:super_admin) &&
@@ -67,7 +67,7 @@ class ApplicationController < ActionController::Base
 
   # Sets the settinfs variable
   def set_user_settings
-    @settings = Setting.find_or_create_by(provider: @user_domain)
+    @settings = Setting.includes(:features).find_or_create_by(provider: @user_domain)
   end
 
   # Redirects the user to a Maintenance page if turned on

app/controllers/concerns/populator.rb

@@ -25,11 +25,11 @@ module Populator
 
     initial_user = case @tab
       when "active"
-        User.without_role(:pending).without_role(:denied)
+        User.includes(:roles).without_role(:pending).without_role(:denied)
       when "deleted"
-        User.deleted
+        User.includes(:roles).deleted
       else
-        User
+        User.includes(:roles)
     end
 
     current_role = Role.find_by(name: @tab, provider: @user_domain) if @tab == "pending" || @tab == "denied"
@@ -57,7 +57,7 @@ module Populator
           .admins_search(@search)
           .admins_order(@order_column, @order_direction)
     else
-      Room.all.admins_search(@search).admins_order(@order_column, @order_direction)
+      Room.includes(:owner).all.admins_search(@search).admins_order(@order_column, @order_direction)
     end
   end
 

app/controllers/rooms_controller.rb

@@ -293,7 +293,7 @@ class RoomsController < ApplicationController
 
   # Find the room from the uid.
   def find_room
-    @room = Room.find_by!(uid: params[:room_uid])
+    @room = Room.includes(:owner).find_by!(uid: params[:room_uid])
   end
 
   # Ensure the user either owns the room or is an admin of the room owner or the room is shared with him

app/controllers/users_controller.rb

@@ -190,7 +190,7 @@ class UsersController < ApplicationController
   private
 
   def find_user
-    @user = User.where(uid: params[:user_uid]).includes(:roles).first
+    @user = User.find_by(uid: params[:user_uid])
   end
 
   # Verify that GreenLight is configured to allow user signup.