From c5f5377e00b64058b5c04ca82cefd6cb646a3638 Mon Sep 17 00:00:00 2001
From: Shadowghost <Shadowghost@users.noreply.github.com>
Date: Sun, 27 Sep 2026 16:30:59 -0400
Subject: Backport pull request #18196 from jellyfin/release-12.z

Skip statistics on an empty library and refresh them after every scan

Original-merge: 83b89218e54754b22831399d592cd0f4b6185812

Merged-by: crobibero <cody@robibe.ro>

Backported-by: Cody Robibero <cody@robibe.ro>
---
 .../Data/SqliteDatabaseStatisticsTests.cs          | 134 +++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 tests/Jellyfin.Server.Implementations.Tests/Data/SqliteDatabaseStatisticsTests.cs

(limited to 'tests/Jellyfin.Server.Implementations.Tests/Data/SqliteDatabaseStatisticsTests.cs')

diff --git a/tests/Jellyfin.Server.Implementations.Tests/Data/SqliteDatabaseStatisticsTests.cs b/tests/Jellyfin.Server.Implementations.Tests/Data/SqliteDatabaseStatisticsTests.cs
new file mode 100644
index 0000000000..153e1dc154
--- /dev/null
+++ b/tests/Jellyfin.Server.Implementations.Tests/Data/SqliteDatabaseStatisticsTests.cs
@@ -0,0 +1,134 @@
+using System;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Jellyfin.Database.Implementations.Entities;
+using Jellyfin.Database.Providers.Sqlite;
+using Jellyfin.Server.Implementations.Tests.Item;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging.Abstractions;
+using Xunit;
+
+namespace Jellyfin.Server.Implementations.Tests.Data;
+
+/// <summary>
+/// Statistics taken on a freshly created database describe every table as a single row, and SQLite then plans
+/// the user data and series queries of a filled library as full scans (#17886).
+/// </summary>
+public sealed class SqliteDatabaseStatisticsTests : SqliteDbTestFixture
+{
+    private readonly SqliteDatabaseProvider _provider;
+
+    public SqliteDatabaseStatisticsTests()
+    {
+        _provider = new SqliteDatabaseProvider(ApplicationPaths, NullLogger<SqliteDatabaseProvider>.Instance)
+        {
+            DbContextFactory = CreateDbContextFactory()
+        };
+    }
+
+    [Fact]
+    public async Task RunScheduledOptimisation_EmptyLibrary_RecordsNoStatistics()
+    {
+        SeedFolders(3);
+
+        await _provider.RunScheduledOptimisation(CancellationToken.None);
+
+        Assert.Null(ReadAnalyzedItemCount());
+    }
+
+    [Fact]
+    public async Task RunScheduledOptimisation_LibraryWithItems_RecordsStatistics()
+    {
+        SeedFolders(1);
+        SeedEpisodes(4);
+
+        await _provider.RunScheduledOptimisation(CancellationToken.None);
+
+        Assert.Equal(CountItems(), ReadAnalyzedItemCount());
+    }
+
+    [Fact]
+    public async Task RefreshStatistics_NoStatistics_Analyzes()
+    {
+        SeedEpisodes(5);
+
+        await _provider.RefreshStatistics(CancellationToken.None);
+
+        Assert.Equal(CountItems(), ReadAnalyzedItemCount());
+    }
+
+    [Fact]
+    public async Task RefreshStatistics_LibraryChanged_Reanalyzes()
+    {
+        SeedEpisodes(10);
+        Analyze();
+        SeedEpisodes(5);
+
+        await _provider.RefreshStatistics(CancellationToken.None);
+
+        Assert.Equal(CountItems(), ReadAnalyzedItemCount());
+    }
+
+    [Fact]
+    public async Task RefreshStatistics_EmptyLibrary_RecordsNoStatistics()
+    {
+        SeedFolders(2);
+
+        await _provider.RefreshStatistics(CancellationToken.None);
+
+        Assert.Null(ReadAnalyzedItemCount());
+    }
+
+    private void SeedFolders(int count)
+    {
+        using var context = CreateDbContext();
+        context.BaseItems.AddRange(Enumerable.Range(0, count).Select(_ => new BaseItemEntity
+        {
+            Id = Guid.NewGuid(),
+            Type = "MediaBrowser.Controller.Entities.Folder",
+            IsFolder = true
+        }));
+        context.SaveChanges();
+    }
+
+    private void SeedEpisodes(int count)
+    {
+        using var context = CreateDbContext();
+        context.BaseItems.AddRange(Enumerable.Range(0, count).Select(_ => new BaseItemEntity
+        {
+            Id = Guid.NewGuid(),
+            Type = "MediaBrowser.Controller.Entities.TV.Episode",
+            IsFolder = false
+        }));
+        context.SaveChanges();
+    }
+
+    private void Analyze()
+    {
+        using var context = CreateDbContext();
+        context.Database.ExecuteSqlRaw("ANALYZE");
+    }
+
+    private long CountItems()
+    {
+        using var context = CreateDbContext();
+        return context.BaseItems.LongCount();
+    }
+
+    private long? ReadAnalyzedItemCount()
+    {
+        using var context = CreateDbContext();
+        var hasStatistics = context.Database
+            .SqlQueryRaw<long>("SELECT count(*) AS \"Value\" FROM sqlite_schema WHERE type = 'table' AND name = 'sqlite_stat1'")
+            .Single();
+        if (hasStatistics == 0)
+        {
+            return null;
+        }
+
+        return context.Database
+            .SqlQueryRaw<long?>("SELECT max(CAST(stat AS INTEGER)) AS \"Value\" FROM sqlite_stat1 WHERE tbl = 'BaseItems'")
+            .Single();
+    }
+}
-- 
cgit v1.2.3