Batch alternate version detection in DtoService to remove MediaSourceCount N+1

Browsing a page of videos with the MediaSourceCount field ran one alternate version query per item, each opening a fresh DbContext. On a large library that turned a single page into hundreds of sequential round trips and made the Items endpoint take tens of seconds while holding a request thread the whole time. Detect which videos own alternate versions once per page with a single query, mirroring the existing people batch. Videos absent from that set have a single media source, so the per item lookups are skipped for the common case. Behavior is unchanged: a video with no alternates already resolved to a count of one. Adds a regression test asserting the count resolves from the batch and the per item lookups are never called.
2026-08-07 22:51:45 -04:00
parent 70ffd25b50
commit c091ffdc6b
6 changed files with 123 additions and 12 deletions
@@ -2234,6 +2234,12 @@ namespace Emby.Server.Implementations.Library
            return [];
        }

+        /// <inheritdoc />
+        public IReadOnlySet<Guid> GetItemsWithAlternateVersions(IReadOnlyList<Guid> itemIds)
+        {
+            return _linkedChildrenService.GetItemsWithAlternateVersions(itemIds);
+        }
+
        /// <inheritdoc />
        public void UpsertLinkedChild(Guid parentId, Guid childId, MediaBrowser.Controller.Entities.LinkedChildType childType)
        {