Revize ecb333b6

Optimized database access - prefetch tags and categories

Backend/Core/Services/TagService/TagServiceEF.cs

@@ -25 +25 @@
 
         public TagTreeResponse GetTagTree()
         {
+            // Prefetch from DB
             var tagCategories = databaseContext.TagCategories.Select(tc => tc).ToList();
+            var tags = databaseContext.Tags.Select(tc => tc).ToList();
+            var subTags = databaseContext.SubTags.Select(tc => tc).ToList();
+
             var tagCategoriesDTOs = new List<TagCategoryInfo>();
             foreach (var tagCategory in tagCategories)
             {
                 var tagCategoryDTO = mapper.Map<TagCategoryInfo>(tagCategory);
-                var tags = databaseContext.Tags.Where(t => t.Category == tagCategory).ToList();
+                var categoryTags = tags.Where(t => t.Category == tagCategory);
                 var tagDTOs = new List<TagInfo>();
 
-                foreach (var tag in tags)
+                foreach (var tag in categoryTags)
                 {
                     var tagDTO = mapper.Map<TagInfo>(tag);
-                    var subTags = databaseContext.SubTags.Where(st => st.Tag == tag).ToList();
+                    var tagSubTags = subTags.Where(st => st.Tag == tag).ToList();
                     var subTagDTOs = new List<SubTagInfo>();
 
-                    if (subTags.Count() != 0)
+                    if (tagSubTags.Count() != 0)
                     {
-                        foreach (var subTag in subTags)
+                        foreach (var subTag in tagSubTags)
                         {
                             subTagDTOs.Add(mapper.Map<SubTagInfo>(subTag));
                         }