Updated the RebuildXmlStructures method with performance improvements. Added cache checking to the GetByPublishedVersion method since published content should always be 'latest' this will speed things up tremendously if items are found there. Added 2 more performance tests which show very large perf improvements, namely the Get_All_Published_Content_Of_Type shows a 77% improvement.

src/Umbraco.Core/Services/ContentService.cs

@@ -13,6 +13,7 @@ using Umbraco.Core.Models.Rdbms;
 using Umbraco.Core.Persistence;
 using Umbraco.Core.Persistence.Caching;
 using Umbraco.Core.Persistence.Querying;
+using Umbraco.Core.Persistence.Repositories;
 using Umbraco.Core.Persistence.UnitOfWork;
 using Umbraco.Core.Publishing;
 
@@ -250,6 +251,17 @@ namespace Umbraco.Core.Services
             }
         }
 
+        internal IEnumerable<IContent> GetPublishedContentOfContentType(int id)
+        {
+            using (var repository = _repositoryFactory.CreateContentRepository(_uowProvider.GetUnitOfWork()))
+            {
+                var query = Query<IContent>.Builder.Where(x => x.ContentTypeId == id);
+                var contents = repository.GetByPublishedVersion(query);
+
+                return contents;
+            }
+        }
+
         /// <summary>
         /// Gets a collection of <see cref="IContent"/> objects by Level
         /// </summary>
@@ -431,6 +443,19 @@ namespace Umbraco.Core.Services
             }
         }
 
+        /// <summary>
+        /// Gets all published content items
+        /// </summary>
+        /// <returns></returns>
+        internal IEnumerable<IContent> GetAllPublished()
+        {
+            using (var repository = _repositoryFactory.CreateContentRepository(_uowProvider.GetUnitOfWork()))
+            {
+                var query = Query<IContent>.Builder.Where(x => x.Trashed == false);
+                return repository.GetByPublishedVersion(query);
+            }
+        }
+
         /// <summary>
         /// Gets a collection of <see cref="IContent"/> objects, which has an expiration date less than or equal to today.
         /// </summary>
@@ -1359,23 +1384,13 @@ namespace Umbraco.Core.Services
                         uow.Database.Execute(@"DELETE FROM cmsContentXml WHERE nodeId IN
                                                 (SELECT DISTINCT cmsContentXml.nodeId FROM cmsContentXml 
                                                     INNER JOIN cmsDocument ON cmsContentXml.nodeId = cmsDocument.nodeId)");
-                        
-                        //get all content items that are published
-                        //  Consider creating a Path query instead of recursive method:
-                        //  var query = Query<IContent>.Builder.Where(x => x.Path.StartsWith("-1"));
-                        var rootContent = GetRootContent();
-                        foreach (var content in rootContent.Where(content => content.Published))
-                        {
-                            list.Add(content);
-                            list.AddRange(GetPublishedDescendants(content));
-                        }                        
+
+                        list.AddRange(GetAllPublished());
                     }
                     else
                     {
                         foreach (var id in contentTypeIds)
                         {
-                            
-
                             //first we'll clear out the data from the cmsContentXml table for this type
                             uow.Database.Execute(@"delete from cmsContentXml where nodeId in 
 (select cmsDocument.nodeId from cmsDocument 
@@ -1383,7 +1398,7 @@ namespace Umbraco.Core.Services
 	where published = 1 and contentType = @contentTypeId)", new {contentTypeId = id});
 
                             //now get all published content objects of this type and add to the list
-                            list.AddRange(GetContentOfContentType(id).Where(content => content.Published));
+                            list.AddRange(GetPublishedContentOfContentType(id));
                         }
                     }