Merge pull request #17576 from obiwantoby/perf/batch-mediasourcecount-dto

Bugfix: #17547 | Batching MediaSourceCount into one call

1 files changed, 83 insertions, 0 deletions

diff --git a/tests/Jellyfin.Server.Implementations.Tests/Dto/DtoServiceImageInheritanceTests.cs b/tests/Jellyfin.Server.Implementations.Tests/Dto/DtoServiceImageInheritanceTests.cs
index d18f8c6cff..6a3dcab57a 100644
--- a/tests/Jellyfin.Server.Implementations.Tests/Dto/DtoServiceImageInheritanceTests.cs
+++ b/tests/Jellyfin.Server.Implementations.Tests/Dto/DtoServiceImageInheritanceTests.cs
@@ -9,6 +9,7 @@ using MediaBrowser.Controller.Drawing;
 using MediaBrowser.Controller.Dto;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Entities.Audio;
+using MediaBrowser.Controller.Entities.Movies;
 using MediaBrowser.Controller.Library;
 using MediaBrowser.Controller.LiveTv;
 using MediaBrowser.Controller.Providers;
@@ -205,6 +206,84 @@ public class DtoServiceImageInheritanceTests
         libraryManager.Verify(x => x.GetPeople(It.IsAny<BaseItem>()), Times.Never);
     }
 
+    [Fact]
+    public void GetBaseItemDtos_Videos_ResolveMediaSourceCountFromBatch_WithoutPerItemLookup()
+    {
+        static Movie MakeMovie() => new Movie
+        {
+            Id = Guid.NewGuid(),
+            Name = "Movie",
+            ImageInfos = []
+        };
+
+        var movieOne = MakeMovie();
+        var movieTwo = MakeMovie();
+
+        var libraryManager = new Mock<ILibraryManager>();
+
+        // DtoService detects which videos own alternate versions in ONE batch
+        // (GetItemIdsWithAlternateVersions) before the per-item loop. Videos absent from that set have a
+        // single media source, so the per-item GetLinkedAlternateVersions/GetLocalAlternateVersionIds
+        // queries (the N+1) must be skipped entirely. Here neither movie has alternate versions.
+        libraryManager
+            .Setup(x => x.GetItemIdsWithAlternateVersions(It.IsAny<IReadOnlyList<Guid>>()))
+            .Returns(new HashSet<Guid>());
+
+        var dtoService = BuildDtoService(libraryManager);
+
+        var options = new DtoOptions(false) { Fields = [ItemFields.MediaSourceCount] };
+        var dtos = dtoService.GetBaseItemDtos([movieOne, movieTwo], options);
+
+        Assert.Equal(2, dtos.Count);
+
+        // A single media source is the default, so the count is left unset (the client treats null as one).
+        foreach (var dto in dtos)
+        {
+            Assert.Null(dto.MediaSourceCount);
+        }
+
+        // The alternate-version check is batched once for the whole set, and the per-item lookups are
+        // never reached because the batch already ruled out alternate versions.
+        libraryManager.Verify(x => x.GetItemIdsWithAlternateVersions(It.IsAny<IReadOnlyList<Guid>>()), Times.Once);
+        libraryManager.Verify(x => x.GetLinkedAlternateVersions(It.IsAny<Video>()), Times.Never);
+        libraryManager.Verify(x => x.GetLocalAlternateVersionIds(It.IsAny<Video>()), Times.Never);
+    }
+
+    [Fact]
+    public void GetBaseItemDtos_VideoInAlternateVersionBatch_ResolvesRealCount()
+    {
+        var movie = new Movie
+        {
+            Id = Guid.NewGuid(),
+            Name = "Movie",
+            ImageInfos = []
+        };
+
+        var libraryManager = new Mock<ILibraryManager>();
+
+        // This movie IS in the batch set, so the fast path must not short-circuit it: the per-item
+        // lookups still run and the count is computed exactly as it was before batching. Two linked
+        // alternate versions plus the movie itself is a count of three.
+        libraryManager
+            .Setup(x => x.GetItemIdsWithAlternateVersions(It.IsAny<IReadOnlyList<Guid>>()))
+            .Returns(new HashSet<Guid> { movie.Id });
+        libraryManager
+            .Setup(x => x.GetLinkedAlternateVersions(It.IsAny<Video>()))
+            .Returns([new Movie { Id = Guid.NewGuid() }, new Movie { Id = Guid.NewGuid() }]);
+        libraryManager
+            .Setup(x => x.GetLocalAlternateVersionIds(It.IsAny<Video>()))
+            .Returns([]);
+
+        var dtoService = BuildDtoService(libraryManager);
+
+        var options = new DtoOptions(false) { Fields = [ItemFields.MediaSourceCount] };
+        var dtos = dtoService.GetBaseItemDtos([movie], options);
+
+        Assert.Single(dtos);
+        Assert.Equal(3, dtos[0].MediaSourceCount);
+        libraryManager.Verify(x => x.GetItemIdsWithAlternateVersions(It.IsAny<IReadOnlyList<Guid>>()), Times.Once);
+    }
+
     private static DtoService BuildDtoService(BaseItem displayParent)
     {
         var libraryManager = new Mock<ILibraryManager>();
@@ -231,6 +310,10 @@ public class DtoServiceImageInheritanceTests
             .Setup(x => x.GetImageCacheTag(It.IsAny<BaseItem>(), It.IsAny<ItemImageInfo>()))
             .Returns<BaseItem, ItemImageInfo>((_, image) => image.Path);
 
+        // Video.IsActiveRecording() dereferences this static during DTO building.
+        Video.RecordingsManager = recordingsManager.Object;
+        BaseItem.LibraryManager = libraryManager.Object;
+
         return new DtoService(
             logger.Object,
             libraryManager.Object,