Merge branch 'master' into authenticationdb-efcore

# Conflicts:
#	Emby.Server.Implementations/Devices/DeviceManager.cs
#	Emby.Server.Implementations/HttpServer/Security/SessionContext.cs
#	Emby.Server.Implementations/Security/AuthenticationRepository.cs
#	Emby.Server.Implementations/Session/SessionManager.cs
#	Jellyfin.Server.Implementations/Security/AuthorizationContext.cs
#	MediaBrowser.Controller/Library/IUserManager.cs
#	MediaBrowser.Controller/Net/ISessionContext.cs

Emby.Server.Implementations/AppBase/BaseApplicationPaths.cs

@@ -33,7 +33,7 @@ namespace Emby.Server.Implementations.AppBase
             CachePath = cacheDirectoryPath;
             WebPath = webDirectoryPath;
 
-            DataPath = Path.Combine(ProgramDataPath, "data");
+            _dataPath = Directory.CreateDirectory(Path.Combine(ProgramDataPath, "data")).FullName;
         }
 
         /// <summary>
@@ -55,11 +55,7 @@ namespace Emby.Server.Implementations.AppBase
         /// Gets the folder path to the data directory.
         /// </summary>
         /// <value>The data directory.</value>
-        public string DataPath
-        {
-            get => _dataPath;
-            private set => _dataPath = Directory.CreateDirectory(value).FullName;
-        }
+        public string DataPath => _dataPath;
 
         /// <inheritdoc />
         public string VirtualDataPath => "%AppDataPath%";

Emby.Server.Implementations/AppBase/BaseConfigurationManager.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
@@ -23,6 +25,11 @@ namespace Emby.Server.Implementations.AppBase
 
         private readonly ConcurrentDictionary<string, object> _configurations = new ConcurrentDictionary<string, object>();
 
+        /// <summary>
+        /// The _configuration sync lock.
+        /// </summary>
+        private readonly object _configurationSyncLock = new object();
+
         private ConfigurationStore[] _configurationStores = Array.Empty<ConfigurationStore>();
         private IConfigurationFactory[] _configurationFactories = Array.Empty<IConfigurationFactory>();
 
@@ -31,11 +38,6 @@ namespace Emby.Server.Implementations.AppBase
         /// </summary>
         private bool _configurationLoaded;
 
-        /// <summary>
-        /// The _configuration sync lock.
-        /// </summary>
-        private readonly object _configurationSyncLock = new object();
-
         /// <summary>
         /// The _configuration.
         /// </summary>
@@ -297,25 +299,29 @@ namespace Emby.Server.Implementations.AppBase
         /// <inheritdoc />
         public object GetConfiguration(string key)
         {
-            return _configurations.GetOrAdd(key, k =>
-            {
-                var file = GetConfigurationFile(key);
-
-                var configurationInfo = _configurationStores
-                    .FirstOrDefault(i => string.Equals(i.Key, key, StringComparison.OrdinalIgnoreCase));
-
-                if (configurationInfo == null)
+            return _configurations.GetOrAdd(
+                key,
+                (k, configurationManager) =>
                 {
-                    throw new ResourceNotFoundException("Configuration with key " + key + " not found.");
-                }
+                    var file = configurationManager.GetConfigurationFile(k);
 
-                var configurationType = configurationInfo.ConfigurationType;
+                    var configurationInfo = Array.Find(
+                        configurationManager._configurationStores,
+                        i => string.Equals(i.Key, k, StringComparison.OrdinalIgnoreCase));
 
-                lock (_configurationSyncLock)
-                {
-                    return LoadConfiguration(file, configurationType);
-                }
-            });
+                    if (configurationInfo == null)
+                    {
+                        throw new ResourceNotFoundException("Configuration with key " + k + " not found.");
+                    }
+
+                    var configurationType = configurationInfo.ConfigurationType;
+
+                    lock (configurationManager._configurationSyncLock)
+                    {
+                        return configurationManager.LoadConfiguration(file, configurationType);
+                    }
+                },
+                this);
         }
 
         private object LoadConfiguration(string path, Type configurationType)

Emby.Server.Implementations/AppBase/ConfigurationHelper.cs

@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.IO;
 using System.Linq;
@@ -35,7 +33,8 @@ namespace Emby.Server.Implementations.AppBase
             }
             catch (Exception)
             {
-                configuration = Activator.CreateInstance(type) ?? throw new ArgumentException($"Provided path ({type}) is not valid.", nameof(type));
+                // Note: CreateInstance returns null for Nullable<T>, e.g. CreateInstance(typeof(int?)) returns null.
+                configuration = Activator.CreateInstance(type)!;
             }
 
             using var stream = new MemoryStream(buffer?.Length ?? 0);

Emby.Server.Implementations/ApplicationHost.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Channels/ChannelManager.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Collections.Generic;
 using System.Globalization;

Emby.Server.Implementations/Collections/CollectionImageProvider.cs

@@ -82,9 +82,9 @@ namespace Emby.Server.Implementations.Collections
                     return null;
                 })
                 .Where(i => i != null)
-                .GroupBy(x => x.Id)
+                .GroupBy(x => x!.Id) // We removed the null values
                 .Select(x => x.First())
-                .ToList();
+                .ToList()!; // Again... the list doesn't contain any null values
         }
 
         /// <inheritdoc />

Emby.Server.Implementations/Collections/CollectionManager.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Collections.Generic;
 using System.IO;

Emby.Server.Implementations/Configuration/ServerConfigurationManager.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Globalization;
 using System.IO;

Emby.Server.Implementations/Cryptography/CryptographyProvider.cs

@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Collections.Generic;
 using System.Security.Cryptography;

Emby.Server.Implementations/Data/BaseSqliteRepository.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Data/ManagedConnection.cs

@@ -9,7 +9,7 @@ namespace Emby.Server.Implementations.Data
 {
     public class ManagedConnection : IDisposable
     {
-        private SQLiteDatabaseConnection _db;
+        private SQLiteDatabaseConnection? _db;
         private readonly SemaphoreSlim _writeLock;
         private bool _disposed = false;
 
@@ -54,12 +54,12 @@ namespace Emby.Server.Implementations.Data
             return _db.RunInTransaction(action, mode);
         }
 
-        public IEnumerable<IReadOnlyList<IResultSetValue>> Query(string sql)
+        public IEnumerable<IReadOnlyList<ResultSetValue>> Query(string sql)
         {
             return _db.Query(sql);
         }
 
-        public IEnumerable<IReadOnlyList<IResultSetValue>> Query(string sql, params object[] values)
+        public IEnumerable<IReadOnlyList<ResultSetValue>> Query(string sql, params object[] values)
         {
             return _db.Query(sql, values);
         }

Emby.Server.Implementations/Data/SqliteExtensions.cs

@@ -1,9 +1,9 @@
+#nullable disable
 #pragma warning disable CS1591
 
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using SQLitePCL.pretty;
 
@@ -65,7 +65,7 @@ namespace Emby.Server.Implementations.Data
             });
         }
 
-        public static Guid ReadGuidFromBlob(this IResultSetValue result)
+        public static Guid ReadGuidFromBlob(this ResultSetValue result)
         {
             return new Guid(result.ToBlob());
         }
@@ -86,7 +86,7 @@ namespace Emby.Server.Implementations.Data
         private static string GetDateTimeKindFormat(DateTimeKind kind)
             => (kind == DateTimeKind.Utc) ? DatetimeFormatUtc : DatetimeFormatLocal;
 
-        public static DateTime ReadDateTime(this IResultSetValue result)
+        public static DateTime ReadDateTime(this ResultSetValue result)
         {
             var dateText = result.ToString();
 
@@ -97,7 +97,7 @@ namespace Emby.Server.Implementations.Data
                 DateTimeStyles.None).ToUniversalTime();
         }
 
-        public static bool TryReadDateTime(this IReadOnlyList<IResultSetValue> reader, int index, out DateTime result)
+        public static bool TryReadDateTime(this IReadOnlyList<ResultSetValue> reader, int index, out DateTime result)
         {
             var item = reader[index];
             if (item.IsDbNull())
@@ -118,7 +118,7 @@ namespace Emby.Server.Implementations.Data
             return false;
         }
 
-        public static bool TryGetGuid(this IReadOnlyList<IResultSetValue> reader, int index, out Guid result)
+        public static bool TryGetGuid(this IReadOnlyList<ResultSetValue> reader, int index, out Guid result)
         {
             var item = reader[index];
             if (item.IsDbNull())
@@ -131,17 +131,17 @@ namespace Emby.Server.Implementations.Data
             return true;
         }
 
-        public static bool IsDbNull(this IResultSetValue result)
+        public static bool IsDbNull(this ResultSetValue result)
         {
             return result.SQLiteType == SQLiteType.Null;
         }
 
-        public static string GetString(this IReadOnlyList<IResultSetValue> result, int index)
+        public static string GetString(this IReadOnlyList<ResultSetValue> result, int index)
         {
             return result[index].ToString();
         }
 
-        public static bool TryGetString(this IReadOnlyList<IResultSetValue> reader, int index, out string result)
+        public static bool TryGetString(this IReadOnlyList<ResultSetValue> reader, int index, out string result)
         {
             result = null;
             var item = reader[index];
@@ -154,12 +154,12 @@ namespace Emby.Server.Implementations.Data
             return true;
         }
 
-        public static bool GetBoolean(this IReadOnlyList<IResultSetValue> result, int index)
+        public static bool GetBoolean(this IReadOnlyList<ResultSetValue> result, int index)
         {
             return result[index].ToBool();
         }
 
-        public static bool TryGetBoolean(this IReadOnlyList<IResultSetValue> reader, int index, out bool result)
+        public static bool TryGetBoolean(this IReadOnlyList<ResultSetValue> reader, int index, out bool result)
         {
             var item = reader[index];
             if (item.IsDbNull())
@@ -172,7 +172,7 @@ namespace Emby.Server.Implementations.Data
             return true;
         }
 
-        public static bool TryGetInt32(this IReadOnlyList<IResultSetValue> reader, int index, out int result)
+        public static bool TryGetInt32(this IReadOnlyList<ResultSetValue> reader, int index, out int result)
         {
             var item = reader[index];
             if (item.IsDbNull())
@@ -185,12 +185,12 @@ namespace Emby.Server.Implementations.Data
             return true;
         }
 
-        public static long GetInt64(this IReadOnlyList<IResultSetValue> result, int index)
+        public static long GetInt64(this IReadOnlyList<ResultSetValue> result, int index)
         {
             return result[index].ToInt64();
         }
 
-        public static bool TryGetInt64(this IReadOnlyList<IResultSetValue> reader, int index, out long result)
+        public static bool TryGetInt64(this IReadOnlyList<ResultSetValue> reader, int index, out long result)
         {
             var item = reader[index];
             if (item.IsDbNull())
@@ -203,7 +203,7 @@ namespace Emby.Server.Implementations.Data
             return true;
         }
 
-        public static bool TryGetSingle(this IReadOnlyList<IResultSetValue> reader, int index, out float result)
+        public static bool TryGetSingle(this IReadOnlyList<ResultSetValue> reader, int index, out float result)
         {
             var item = reader[index];
             if (item.IsDbNull())
@@ -216,7 +216,7 @@ namespace Emby.Server.Implementations.Data
             return true;
         }
 
-        public static bool TryGetDouble(this IReadOnlyList<IResultSetValue> reader, int index, out double result)
+        public static bool TryGetDouble(this IReadOnlyList<ResultSetValue> reader, int index, out double result)
         {
             var item = reader[index];
             if (item.IsDbNull())
@@ -229,7 +229,7 @@ namespace Emby.Server.Implementations.Data
             return true;
         }
 
-        public static Guid GetGuid(this IReadOnlyList<IResultSetValue> result, int index)
+        public static Guid GetGuid(this IReadOnlyList<ResultSetValue> result, int index)
         {
             return result[index].ReadGuidFromBlob();
         }
@@ -441,7 +441,7 @@ namespace Emby.Server.Implementations.Data
             }
         }
 
-        public static IEnumerable<IReadOnlyList<IResultSetValue>> ExecuteQuery(this IStatement statement)
+        public static IEnumerable<IReadOnlyList<ResultSetValue>> ExecuteQuery(this IStatement statement)
         {
             while (statement.MoveNext())
             {

Emby.Server.Implementations/Data/SqliteItemRepository.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -41,6 +43,7 @@ namespace Emby.Server.Implementations.Data
     /// </summary>
     public class SqliteItemRepository : BaseSqliteRepository, IItemRepository
     {
+        private const string FromText = " from TypedBaseItems A";
         private const string ChaptersTableName = "Chapters2";
 
         private readonly IServerConfigurationManager _config;
@@ -1043,18 +1046,34 @@ namespace Emby.Server.Implementations.Data
                 return Array.Empty<ItemImageInfo>();
             }
 
-            var list = new List<ItemImageInfo>();
-            foreach (var part in value.SpanSplit('|'))
+            // TODO The following is an ugly performance optimization, but it's extremely unlikely that the data in the database would be malformed
+            var valueSpan = value.AsSpan();
+            var count = valueSpan.Count('|') + 1;
+
+            var position = 0;
+            var result = new ItemImageInfo[count];
+            foreach (var part in valueSpan.Split('|'))
             {
                 var image = ItemImageInfoFromValueString(part);
 
                 if (image != null)
                 {
-                    list.Add(image);
+                    result[position++] = image;
                 }
             }
 
-            return list.ToArray();
+            if (position == count)
+            {
+                return result;
+            }
+
+            if (position == 0)
+            {
+                return Array.Empty<ItemImageInfo>();
+            }
+
+            // Extremely unlikely, but somehow one or more of the image strings were malformed. Cut the array.
+            return result[..position];
         }
 
         private void AppendItemImageInfo(StringBuilder bldr, ItemImageInfo image)
@@ -1282,12 +1301,12 @@ namespace Emby.Server.Implementations.Data
             return true;
         }
 
-        private BaseItem GetItem(IReadOnlyList<IResultSetValue> reader, InternalItemsQuery query)
+        private BaseItem GetItem(IReadOnlyList<ResultSetValue> reader, InternalItemsQuery query)
         {
             return GetItem(reader, query, HasProgramAttributes(query), HasEpisodeAttributes(query), HasServiceName(query), HasStartDate(query), HasTrailerTypes(query), HasArtistFields(query), HasSeriesFields(query));
         }
 
-        private BaseItem GetItem(IReadOnlyList<IResultSetValue> reader, InternalItemsQuery query, bool enableProgramAttributes, bool hasEpisodeAttributes, bool hasServiceName, bool queryHasStartDate, bool hasTrailerTypes, bool hasArtistFields, bool hasSeriesFields)
+        private BaseItem GetItem(IReadOnlyList<ResultSetValue> reader, InternalItemsQuery query, bool enableProgramAttributes, bool hasEpisodeAttributes, bool hasServiceName, bool queryHasStartDate, bool hasTrailerTypes, bool hasArtistFields, bool hasSeriesFields)
         {
             var typeString = reader.GetString(0);
 
@@ -1927,7 +1946,7 @@ namespace Emby.Server.Implementations.Data
         /// <param name="reader">The reader.</param>
         /// <param name="item">The item.</param>
         /// <returns>ChapterInfo.</returns>
-        private ChapterInfo GetChapter(IReadOnlyList<IResultSetValue> reader, BaseItem item)
+        private ChapterInfo GetChapter(IReadOnlyList<ResultSetValue> reader, BaseItem item)
         {
             var chapter = new ChapterInfo
             {
@@ -2248,10 +2267,8 @@ namespace Emby.Server.Implementations.Data
             return query.IncludeItemTypes.Any(x => _seriesTypes.Contains(x));
         }
 
-        private List<string> GetFinalColumnsToSelect(InternalItemsQuery query, IEnumerable<string> startColumns)
+        private void SetFinalColumnsToSelect(InternalItemsQuery query, List<string> columns)
         {
-            var list = startColumns.ToList();
-
             foreach (var field in _allFields)
             {
                 if (!HasField(query, field))
@@ -2259,28 +2276,28 @@ namespace Emby.Server.Implementations.Data
                     switch (field)
                     {
                         case ItemFields.Settings:
-                            list.Remove("IsLocked");
-                            list.Remove("PreferredMetadataCountryCode");
-                            list.Remove("PreferredMetadataLanguage");
-                            list.Remove("LockedFields");
+                            columns.Remove("IsLocked");
+                            columns.Remove("PreferredMetadataCountryCode");
+                            columns.Remove("PreferredMetadataLanguage");
+                            columns.Remove("LockedFields");
                             break;
                         case ItemFields.ServiceName:
-                            list.Remove("ExternalServiceId");
+                            columns.Remove("ExternalServiceId");
                             break;
                         case ItemFields.SortName:
-                            list.Remove("ForcedSortName");
+                            columns.Remove("ForcedSortName");
                             break;
                         case ItemFields.Taglines:
-                            list.Remove("Tagline");
+                            columns.Remove("Tagline");
                             break;
                         case ItemFields.Tags:
-                            list.Remove("Tags");
+                            columns.Remove("Tags");
                             break;
                         case ItemFields.IsHD:
                             // do nothing
                             break;
                         default:
-                            list.Remove(field.ToString());
+                            columns.Remove(field.ToString());
                             break;
                     }
                 }
@@ -2288,60 +2305,60 @@ namespace Emby.Server.Implementations.Data
 
             if (!HasProgramAttributes(query))
             {
-                list.Remove("IsMovie");
-                list.Remove("IsSeries");
-                list.Remove("EpisodeTitle");
-                list.Remove("IsRepeat");
-                list.Remove("ShowId");
+                columns.Remove("IsMovie");
+                columns.Remove("IsSeries");
+                columns.Remove("EpisodeTitle");
+                columns.Remove("IsRepeat");
+                columns.Remove("ShowId");
             }
 
             if (!HasEpisodeAttributes(query))
             {
-                list.Remove("SeasonName");
-                list.Remove("SeasonId");
+                columns.Remove("SeasonName");
+                columns.Remove("SeasonId");
             }
 
             if (!HasStartDate(query))
             {
-                list.Remove("StartDate");
+                columns.Remove("StartDate");
             }
 
             if (!HasTrailerTypes(query))
             {
-                list.Remove("TrailerTypes");
+                columns.Remove("TrailerTypes");
             }
 
             if (!HasArtistFields(query))
             {
-                list.Remove("AlbumArtists");
-                list.Remove("Artists");
+                columns.Remove("AlbumArtists");
+                columns.Remove("Artists");
             }
 
             if (!HasSeriesFields(query))
             {
-                list.Remove("SeriesId");
+                columns.Remove("SeriesId");
             }
 
             if (!HasEpisodeAttributes(query))
             {
-                list.Remove("SeasonName");
-                list.Remove("SeasonId");
+                columns.Remove("SeasonName");
+                columns.Remove("SeasonId");
             }
 
             if (!query.DtoOptions.EnableImages)
             {
-                list.Remove("Images");
+                columns.Remove("Images");
             }
 
             if (EnableJoinUserData(query))
             {
-                list.Add("UserDatas.UserId");
-                list.Add("UserDatas.lastPlayedDate");
-                list.Add("UserDatas.playbackPositionTicks");
-                list.Add("UserDatas.playcount");
-                list.Add("UserDatas.isFavorite");
-                list.Add("UserDatas.played");
-                list.Add("UserDatas.rating");
+                columns.Add("UserDatas.UserId");
+                columns.Add("UserDatas.lastPlayedDate");
+                columns.Add("UserDatas.playbackPositionTicks");
+                columns.Add("UserDatas.playcount");
+                columns.Add("UserDatas.isFavorite");
+                columns.Add("UserDatas.played");
+                columns.Add("UserDatas.rating");
             }
 
             if (query.SimilarTo != null)
@@ -2389,7 +2406,7 @@ namespace Emby.Server.Implementations.Data
 
                 builder.Append(") as SimilarityScore");
 
-                list.Add(builder.ToString());
+                columns.Add(builder.ToString());
 
                 var oldLen = query.ExcludeItemIds.Length;
                 var newLen = oldLen + item.ExtraIds.Length + 1;
@@ -2416,10 +2433,8 @@ namespace Emby.Server.Implementations.Data
 
                 builder.Append(") as SearchScore");
 
-                list.Add(builder.ToString());
+                columns.Add(builder.ToString());
             }
-
-            return list;
         }
 
         private void BindSearchParams(InternalItemsQuery query, IStatement statement)
@@ -2485,31 +2500,25 @@ namespace Emby.Server.Implementations.Data
 
         private string GetGroupBy(InternalItemsQuery query)
         {
-            var groups = new List<string>();
-
-            if (EnableGroupByPresentationUniqueKey(query))
+            var enableGroupByPresentationUniqueKey = EnableGroupByPresentationUniqueKey(query);
+            if (enableGroupByPresentationUniqueKey && query.GroupBySeriesPresentationUniqueKey)
             {
-                groups.Add("PresentationUniqueKey");
+                return " Group by PresentationUniqueKey, SeriesPresentationUniqueKey";
+            }
+
+            if (enableGroupByPresentationUniqueKey)
+            {
+                return " Group by PresentationUniqueKey";
             }
 
             if (query.GroupBySeriesPresentationUniqueKey)
             {
-                groups.Add("SeriesPresentationUniqueKey");
-            }
-
-            if (groups.Count > 0)
-            {
-                return " Group by " + string.Join(',', groups);
+                return " Group by SeriesPresentationUniqueKey";
             }
 
             return string.Empty;
         }
 
-        private string GetFromText(string alias = "A")
-        {
-            return " from TypedBaseItems " + alias;
-        }
-
         public int GetCount(InternalItemsQuery query)
         {
             if (query == null)
@@ -2527,17 +2536,21 @@ namespace Emby.Server.Implementations.Data
                 query.Limit = query.Limit.Value + 4;
             }
 
-            var commandText = "select "
-                              + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count(distinct PresentationUniqueKey)" }))
-                              + GetFromText()
-                              + GetJoinUserDataText(query);
+            var columns = new List<string> { "count(distinct PresentationUniqueKey)" };
+            SetFinalColumnsToSelect(query, columns);
+            var commandTextBuilder = new StringBuilder("select ", 256)
+                .AppendJoin(',', columns)
+                .Append(FromText)
+                .Append(GetJoinUserDataText(query));
 
             var whereClauses = GetWhereClauses(query, null);
             if (whereClauses.Count != 0)
             {
-                commandText += " where " + string.Join(" AND ", whereClauses);
+                commandTextBuilder.Append(" where ")
+                    .AppendJoin(" AND ", whereClauses);
             }
 
+            var commandText = commandTextBuilder.ToString();
             int count;
             using (var connection = GetConnection(true))
             {
@@ -2579,20 +2592,23 @@ namespace Emby.Server.Implementations.Data
                 query.Limit = query.Limit.Value + 4;
             }
 
-            var commandText = "select "
-                            + string.Join(',', GetFinalColumnsToSelect(query, _retriveItemColumns))
-                            + GetFromText()
-                            + GetJoinUserDataText(query);
+            var columns = _retriveItemColumns.ToList();
+            SetFinalColumnsToSelect(query, columns);
+            var commandTextBuilder = new StringBuilder("select ", 1024)
+                .AppendJoin(',', columns)
+                .Append(FromText)
+                .Append(GetJoinUserDataText(query));
 
             var whereClauses = GetWhereClauses(query, null);
 
             if (whereClauses.Count != 0)
             {
-                commandText += " where " + string.Join(" AND ", whereClauses);
+                commandTextBuilder.Append(" where ")
+                    .AppendJoin(" AND ", whereClauses);
             }
 
-            commandText += GetGroupBy(query)
-                        + GetOrderByText(query);
+            commandTextBuilder.Append(GetGroupBy(query))
+                .Append(GetOrderByText(query));
 
             if (query.Limit.HasValue || query.StartIndex.HasValue)
             {
@@ -2600,15 +2616,18 @@ namespace Emby.Server.Implementations.Data
 
                 if (query.Limit.HasValue || offset > 0)
                 {
-                    commandText += " LIMIT " + (query.Limit ?? int.MaxValue).ToString(CultureInfo.InvariantCulture);
+                    commandTextBuilder.Append(" LIMIT ")
+                        .Append(query.Limit ?? int.MaxValue);
                 }
 
                 if (offset > 0)
                 {
-                    commandText += " OFFSET " + offset.ToString(CultureInfo.InvariantCulture);
+                    commandTextBuilder.Append(" OFFSET ")
+                        .Append(offset);
                 }
             }
 
+            var commandText = commandTextBuilder.ToString();
             var items = new List<BaseItem>();
             using (var connection = GetConnection(true))
             {
@@ -2764,20 +2783,27 @@ namespace Emby.Server.Implementations.Data
                 query.Limit = query.Limit.Value + 4;
             }
 
-            var commandText = "select "
-                            + string.Join(',', GetFinalColumnsToSelect(query, _retriveItemColumns))
-                            + GetFromText()
-                            + GetJoinUserDataText(query);
+            var columns = _retriveItemColumns.ToList();
+            SetFinalColumnsToSelect(query, columns);
+            var commandTextBuilder = new StringBuilder("select ", 512)
+                .AppendJoin(',', columns)
+                .Append(FromText)
+                .Append(GetJoinUserDataText(query));
 
             var whereClauses = GetWhereClauses(query, null);
 
             var whereText = whereClauses.Count == 0 ?
                 string.Empty :
-                " where " + string.Join(" AND ", whereClauses);
+                string.Join(" AND ", whereClauses);
 
-            commandText += whereText
-                        + GetGroupBy(query)
-                        + GetOrderByText(query);
+            if (!string.IsNullOrEmpty(whereText))
+            {
+                commandTextBuilder.Append(" where ")
+                    .Append(whereText);
+            }
+
+            commandTextBuilder.Append(GetGroupBy(query))
+                .Append(GetOrderByText(query));
 
             if (query.Limit.HasValue || query.StartIndex.HasValue)
             {
@@ -2785,43 +2811,58 @@ namespace Emby.Server.Implementations.Data
 
                 if (query.Limit.HasValue || offset > 0)
                 {
-                    commandText += " LIMIT " + (query.Limit ?? int.MaxValue).ToString(CultureInfo.InvariantCulture);
+                    commandTextBuilder.Append(" LIMIT ")
+                        .Append(query.Limit ?? int.MaxValue);
                 }
 
                 if (offset > 0)
                 {
-                    commandText += " OFFSET " + offset.ToString(CultureInfo.InvariantCulture);
+                    commandTextBuilder.Append(" OFFSET ")
+                        .Append(offset);
                 }
             }
 
             var isReturningZeroItems = query.Limit.HasValue && query.Limit <= 0;
 
-            var statementTexts = new List<string>();
+            var itemQuery = string.Empty;
+            var totalRecordCountQuery = string.Empty;
             if (!isReturningZeroItems)
             {
-                statementTexts.Add(commandText);
+                itemQuery = commandTextBuilder.ToString();
             }
 
             if (query.EnableTotalRecordCount)
             {
-                commandText = string.Empty;
+                commandTextBuilder.Clear();
 
+                commandTextBuilder.Append(" select ");
+
+                List<string> columnsToSelect;
                 if (EnableGroupByPresentationUniqueKey(query))
                 {
-                    commandText += " select " + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count (distinct PresentationUniqueKey)" })) + GetFromText();
+                    columnsToSelect = new List<string> { "count (distinct PresentationUniqueKey)" };
                 }
                 else if (query.GroupBySeriesPresentationUniqueKey)
                 {
-                    commandText += " select " + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count (distinct SeriesPresentationUniqueKey)" })) + GetFromText();
+                    columnsToSelect = new List<string> { "count (distinct SeriesPresentationUniqueKey)" };
                 }
                 else
                 {
-                    commandText += " select " + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count (guid)" })) + GetFromText();
+                    columnsToSelect = new List<string> { "count (guid)" };
                 }
 
-                commandText += GetJoinUserDataText(query)
-                            + whereText;
-                statementTexts.Add(commandText);
+                SetFinalColumnsToSelect(query, columnsToSelect);
+
+                commandTextBuilder.AppendJoin(',', columnsToSelect)
+                    .Append(FromText)
+                    .Append(GetJoinUserDataText(query));
+                if (!string.IsNullOrEmpty(whereText))
+                {
+                    commandTextBuilder.Append(" where ")
+                        .Append(whereText);
+                }
+
+                totalRecordCountQuery = commandTextBuilder.ToString();
             }
 
             var list = new List<BaseItem>();
@@ -2831,11 +2872,12 @@ namespace Emby.Server.Implementations.Data
                 connection.RunInTransaction(
                 db =>
                 {
-                    var statements = PrepareAll(db, statementTexts);
+                    var itemQueryStatement = PrepareStatement(db, itemQuery);
+                    var totalRecordCountQueryStatement = PrepareStatement(db, totalRecordCountQuery);
 
                     if (!isReturningZeroItems)
                     {
-                        using (var statement = statements[0])
+                        using (var statement = itemQueryStatement)
                         {
                             if (EnableJoinUserData(query))
                             {
@@ -2865,11 +2907,14 @@ namespace Emby.Server.Implementations.Data
                                 }
                             }
                         }
+
+                        LogQueryTime("GetItems.ItemQuery", itemQuery, now);
                     }
 
+                    now = DateTime.UtcNow;
                     if (query.EnableTotalRecordCount)
                     {
-                        using (var statement = statements[statements.Length - 1])
+                        using (var statement = totalRecordCountQueryStatement)
                         {
                             if (EnableJoinUserData(query))
                             {
@@ -2884,11 +2929,12 @@ namespace Emby.Server.Implementations.Data
 
                             result.TotalRecordCount = statement.ExecuteQuery().SelectScalarInt().First();
                         }
+
+                        LogQueryTime("GetItems.TotalRecordCount", totalRecordCountQuery, now);
                     }
                 }, ReadTransactionMode);
             }
 
-            LogQueryTime("GetItems", commandText, now);
             result.Items = list;
             return result;
         }
@@ -3021,19 +3067,22 @@ namespace Emby.Server.Implementations.Data
 
             var now = DateTime.UtcNow;
 
-            var commandText = "select "
-                            + string.Join(',', GetFinalColumnsToSelect(query, new[] { "guid" }))
-                            + GetFromText()
-                            + GetJoinUserDataText(query);
+            var columns = new List<string> { "guid" };
+            SetFinalColumnsToSelect(query, columns);
+            var commandTextBuilder = new StringBuilder("select ", 256)
+                .AppendJoin(',', columns)
+                .Append(FromText)
+                .Append(GetJoinUserDataText(query));
 
             var whereClauses = GetWhereClauses(query, null);
             if (whereClauses.Count != 0)
             {
-                commandText += " where " + string.Join(" AND ", whereClauses);
+                commandTextBuilder.Append(" where ")
+                    .AppendJoin(" AND ", whereClauses);
             }
 
-            commandText += GetGroupBy(query)
-                        + GetOrderByText(query);
+            commandTextBuilder.Append(GetGroupBy(query))
+                .Append(GetOrderByText(query));
 
             if (query.Limit.HasValue || query.StartIndex.HasValue)
             {
@@ -3041,15 +3090,18 @@ namespace Emby.Server.Implementations.Data
 
                 if (query.Limit.HasValue || offset > 0)
                 {
-                    commandText += " LIMIT " + (query.Limit ?? int.MaxValue).ToString(CultureInfo.InvariantCulture);
+                    commandTextBuilder.Append(" LIMIT ")
+                        .Append(query.Limit ?? int.MaxValue);
                 }
 
                 if (offset > 0)
                 {
-                    commandText += " OFFSET " + offset.ToString(CultureInfo.InvariantCulture);
+                    commandTextBuilder.Append(" OFFSET ")
+                        .Append(offset);
                 }
             }
 
+            var commandText = commandTextBuilder.ToString();
             var list = new List<Guid>();
             using (var connection = GetConnection(true))
             {
@@ -3088,7 +3140,9 @@ namespace Emby.Server.Implementations.Data
 
             var now = DateTime.UtcNow;
 
-            var commandText = "select " + string.Join(',', GetFinalColumnsToSelect(query, new[] { "guid", "path" })) + GetFromText();
+            var columns = new List<string> { "guid", "path" };
+            SetFinalColumnsToSelect(query, columns);
+            var commandText = "select " + string.Join(',', columns) + FromText;
 
             var whereClauses = GetWhereClauses(query, null);
             if (whereClauses.Count != 0)
@@ -3164,9 +3218,11 @@ namespace Emby.Server.Implementations.Data
 
             var now = DateTime.UtcNow;
 
+            var columns = new List<string> { "guid" };
+            SetFinalColumnsToSelect(query, columns);
             var commandText = "select "
-                            + string.Join(',', GetFinalColumnsToSelect(query, new[] { "guid" }))
-                            + GetFromText()
+                            + string.Join(',', columns)
+                            + FromText
                             + GetJoinUserDataText(query);
 
             var whereClauses = GetWhereClauses(query, null);
@@ -3206,19 +3262,23 @@ namespace Emby.Server.Implementations.Data
             {
                 commandText = string.Empty;
 
+                List<string> columnsToSelect;
                 if (EnableGroupByPresentationUniqueKey(query))
                 {
-                    commandText += " select " + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count (distinct PresentationUniqueKey)" })) + GetFromText();
+                    columnsToSelect = new List<string> { "count (distinct PresentationUniqueKey)" };
                 }
                 else if (query.GroupBySeriesPresentationUniqueKey)
                 {
-                    commandText += " select " + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count (distinct SeriesPresentationUniqueKey)" })) + GetFromText();
+                    columnsToSelect = new List<string> { "count (distinct SeriesPresentationUniqueKey)" };
                 }
                 else
                 {
-                    commandText += " select " + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count (guid)" })) + GetFromText();
+                    columnsToSelect = new List<string> { "count (guid)" };
                 }
 
+                SetFinalColumnsToSelect(query, columnsToSelect);
+                commandText += " select " + string.Join(',', columnsToSelect) + FromText;
+
                 commandText += GetJoinUserDataText(query)
                             + whereText;
                 statementTexts.Add(commandText);
@@ -4413,56 +4473,50 @@ namespace Emby.Server.Implementations.Data
                 whereClauses.Add(GetProviderIdClause(query.HasTvdbId.Value, "tvdb"));
             }
 
-            var includedItemByNameTypes = GetItemByNameTypesInQuery(query);
-            var enableItemsByName = (query.IncludeItemsByName ?? false) && includedItemByNameTypes.Count > 0;
-
             var queryTopParentIds = query.TopParentIds;
 
-            if (queryTopParentIds.Length == 1)
+            if (queryTopParentIds.Length > 0)
             {
-                if (enableItemsByName && includedItemByNameTypes.Count == 1)
-                {
-                    whereClauses.Add("(TopParentId=@TopParentId or Type=@IncludedItemByNameType)");
-                    if (statement != null)
-                    {
-                        statement.TryBind("@IncludedItemByNameType", includedItemByNameTypes[0]);
-                    }
-                }
-                else if (enableItemsByName && includedItemByNameTypes.Count > 1)
-                {
-                    var itemByNameTypeVal = string.Join(',', includedItemByNameTypes.Select(i => "'" + i + "'"));
-                    whereClauses.Add("(TopParentId=@TopParentId or Type in (" + itemByNameTypeVal + "))");
-                }
-                else
-                {
-                    whereClauses.Add("(TopParentId=@TopParentId)");
-                }
+                var includedItemByNameTypes = GetItemByNameTypesInQuery(query);
+                var enableItemsByName = (query.IncludeItemsByName ?? false) && includedItemByNameTypes.Count > 0;
 
-                if (statement != null)
+                if (queryTopParentIds.Length == 1)
                 {
-                    statement.TryBind("@TopParentId", queryTopParentIds[0].ToString("N", CultureInfo.InvariantCulture));
-                }
-            }
-            else if (queryTopParentIds.Length > 1)
-            {
-                var val = string.Join(',', queryTopParentIds.Select(i => "'" + i.ToString("N", CultureInfo.InvariantCulture) + "'"));
-
-                if (enableItemsByName && includedItemByNameTypes.Count == 1)
-                {
-                    whereClauses.Add("(Type=@IncludedItemByNameType or TopParentId in (" + val + "))");
-                    if (statement != null)
+                    if (enableItemsByName && includedItemByNameTypes.Count == 1)
                     {
-                        statement.TryBind("@IncludedItemByNameType", includedItemByNameTypes[0]);
+                        whereClauses.Add("(TopParentId=@TopParentId or Type=@IncludedItemByNameType)");
+                        statement?.TryBind("@IncludedItemByNameType", includedItemByNameTypes[0]);
                     }
+                    else if (enableItemsByName && includedItemByNameTypes.Count > 1)
+                    {
+                        var itemByNameTypeVal = string.Join(',', includedItemByNameTypes.Select(i => "'" + i + "'"));
+                        whereClauses.Add("(TopParentId=@TopParentId or Type in (" + itemByNameTypeVal + "))");
+                    }
+                    else
+                    {
+                        whereClauses.Add("(TopParentId=@TopParentId)");
+                    }
+
+                    statement?.TryBind("@TopParentId", queryTopParentIds[0].ToString("N", CultureInfo.InvariantCulture));
                 }
-                else if (enableItemsByName && includedItemByNameTypes.Count > 1)
+                else if (queryTopParentIds.Length > 1)
                 {
-                    var itemByNameTypeVal = string.Join(',', includedItemByNameTypes.Select(i => "'" + i + "'"));
-                    whereClauses.Add("(Type in (" + itemByNameTypeVal + ") or TopParentId in (" + val + "))");
-                }
-                else
-                {
-                    whereClauses.Add("TopParentId in (" + val + ")");
+                    var val = string.Join(',', queryTopParentIds.Select(i => "'" + i.ToString("N", CultureInfo.InvariantCulture) + "'"));
+
+                    if (enableItemsByName && includedItemByNameTypes.Count == 1)
+                    {
+                        whereClauses.Add("(Type=@IncludedItemByNameType or TopParentId in (" + val + "))");
+                        statement?.TryBind("@IncludedItemByNameType", includedItemByNameTypes[0]);
+                    }
+                    else if (enableItemsByName && includedItemByNameTypes.Count > 1)
+                    {
+                        var itemByNameTypeVal = string.Join(',', includedItemByNameTypes.Select(i => "'" + i + "'"));
+                        whereClauses.Add("(Type in (" + itemByNameTypeVal + ") or TopParentId in (" + val + "))");
+                    }
+                    else
+                    {
+                        whereClauses.Add("TopParentId in (" + val + ")");
+                    }
                 }
             }
 
@@ -4744,17 +4798,12 @@ namespace Emby.Server.Implementations.Data
                 return true;
             }
 
-            var types = new[]
-            {
-                nameof(Episode),
-                nameof(Video),
-                nameof(Movie),
-                nameof(MusicVideo),
-                nameof(Series),
-                nameof(Season)
-            };
-
-            if (types.Any(i => query.IncludeItemTypes.Contains(i, StringComparer.OrdinalIgnoreCase)))
+            if (query.IncludeItemTypes.Contains(nameof(Episode), StringComparer.OrdinalIgnoreCase)
+                || query.IncludeItemTypes.Contains(nameof(Video), StringComparer.OrdinalIgnoreCase)
+                || query.IncludeItemTypes.Contains(nameof(Movie), StringComparer.OrdinalIgnoreCase)
+                || query.IncludeItemTypes.Contains(nameof(MusicVideo), StringComparer.OrdinalIgnoreCase)
+                || query.IncludeItemTypes.Contains(nameof(Series), StringComparer.OrdinalIgnoreCase)
+                || query.IncludeItemTypes.Contains(nameof(Season), StringComparer.OrdinalIgnoreCase))
             {
                 return true;
             }
@@ -5198,37 +5247,45 @@ AND Type = @InternalPersonType)");
 
             var now = DateTime.UtcNow;
 
-            var typeClause = itemValueTypes.Length == 1 ?
-                ("Type=" + itemValueTypes[0].ToString(CultureInfo.InvariantCulture)) :
-                ("Type in (" + string.Join(',', itemValueTypes.Select(i => i.ToString(CultureInfo.InvariantCulture))) + ")");
-
-            var commandText = "Select Value From ItemValues where " + typeClause;
+            var stringBuilder = new StringBuilder("Select Value From ItemValues where Type", 128);
+            if (itemValueTypes.Length == 1)
+            {
+                stringBuilder.Append('=')
+                    .Append(itemValueTypes[0]);
+            }
+            else
+            {
+                stringBuilder.Append(" in (")
+                    .AppendJoin(',', itemValueTypes)
+                    .Append(')');
+            }
 
             if (withItemTypes.Count > 0)
             {
-                var typeString = string.Join(',', withItemTypes.Select(i => "'" + i + "'"));
-                commandText += " AND ItemId In (select guid from typedbaseitems where type in (" + typeString + "))";
+                stringBuilder.Append(" AND ItemId In (select guid from typedbaseitems where type in (")
+                    .AppendJoinInSingleQuotes(',', withItemTypes)
+                    .Append("))");
             }
 
             if (excludeItemTypes.Count > 0)
             {
-                var typeString = string.Join(',', excludeItemTypes.Select(i => "'" + i + "'"));
-                commandText += " AND ItemId not In (select guid from typedbaseitems where type in (" + typeString + "))";
+                stringBuilder.Append(" AND ItemId not In (select guid from typedbaseitems where type in (")
+                    .AppendJoinInSingleQuotes(',', excludeItemTypes)
+                    .Append("))");
             }
 
-            commandText += " Group By CleanValue";
+            stringBuilder.Append(" Group By CleanValue");
+            var commandText = stringBuilder.ToString();
 
             var list = new List<string>();
             using (var connection = GetConnection(true))
+            using (var statement = PrepareStatement(connection, commandText))
             {
-                using (var statement = PrepareStatement(connection, commandText))
+                foreach (var row in statement.ExecuteQuery())
                 {
-                    foreach (var row in statement.ExecuteQuery())
+                    if (row.TryGetString(0, out var result))
                     {
-                        if (row.TryGetString(0, out var result))
-                        {
-                            list.Add(result);
-                        }
+                        list.Add(result);
                     }
                 }
             }
@@ -5254,18 +5311,19 @@ AND Type = @InternalPersonType)");
             var now = DateTime.UtcNow;
 
             var typeClause = itemValueTypes.Length == 1 ?
-                ("Type=" + itemValueTypes[0].ToString(CultureInfo.InvariantCulture)) :
-                ("Type in (" + string.Join(',', itemValueTypes.Select(i => i.ToString(CultureInfo.InvariantCulture))) + ")");
+                ("Type=" + itemValueTypes[0]) :
+                ("Type in (" + string.Join(',', itemValueTypes) + ")");
 
             InternalItemsQuery typeSubQuery = null;
 
-            Dictionary<string, string> itemCountColumns = null;
+            string itemCountColumns = null;
 
+            var stringBuilder = new StringBuilder(1024);
             var typesToCount = query.IncludeItemTypes;
 
             if (typesToCount.Length > 0)
             {
-                var itemCountColumnQuery = "select group_concat(type, '|')" + GetFromText("B");
+                stringBuilder.Append("(select group_concat(type, '|') from TypedBaseItems B");
 
                 typeSubQuery = new InternalItemsQuery(query.User)
                 {
@@ -5281,20 +5339,22 @@ AND Type = @InternalPersonType)");
                 };
                 var whereClauses = GetWhereClauses(typeSubQuery, null);
 
-                whereClauses.Add("guid in (select ItemId from ItemValues where ItemValues.CleanValue=A.CleanName AND " + typeClause + ")");
+                stringBuilder.Append(" where ")
+                    .AppendJoin(" AND ", whereClauses)
+                    .Append(" AND ")
+                    .Append("guid in (select ItemId from ItemValues where ItemValues.CleanValue=A.CleanName AND ")
+                    .Append(typeClause)
+                    .Append(")) as itemTypes");
 
-                itemCountColumnQuery += " where " + string.Join(" AND ", whereClauses);
-
-                itemCountColumns = new Dictionary<string, string>()
-                {
-                    { "itemTypes", "(" + itemCountColumnQuery + ") as itemTypes" }
-                };
+                itemCountColumns = stringBuilder.ToString();
+                stringBuilder.Clear();
             }
 
             List<string> columns = _retriveItemColumns.ToList();
-            if (itemCountColumns != null)
+            // Unfortunately we need to add it to columns to ensure the order of the columns in the select
+            if (!string.IsNullOrEmpty(itemCountColumns))
             {
-                columns.AddRange(itemCountColumns.Values);
+                columns.Add(itemCountColumns);
             }
 
             // do this first before calling GetFinalColumnsToSelect, otherwise ExcludeItemIds will be set by SimilarTo
@@ -5315,20 +5375,20 @@ AND Type = @InternalPersonType)");
                 IsSeries = query.IsSeries
             };
 
-            columns = GetFinalColumnsToSelect(query, columns);
-
-            var commandText = "select "
-                            + string.Join(',', columns)
-                            + GetFromText()
-                            + GetJoinUserDataText(query);
+            SetFinalColumnsToSelect(query, columns);
 
             var innerWhereClauses = GetWhereClauses(innerQuery, null);
 
-            var innerWhereText = innerWhereClauses.Count == 0 ?
-                string.Empty :
-                " where " + string.Join(" AND ", innerWhereClauses);
+            stringBuilder.Append(" where Type=@SelectType And CleanName In (Select CleanValue from ItemValues where ")
+                .Append(typeClause)
+                .Append(" AND ItemId in (select guid from TypedBaseItems");
+            if (innerWhereClauses.Count > 0)
+            {
+                stringBuilder.Append(" where ")
+                    .AppendJoin(" AND ", innerWhereClauses);
+            }
 
-            var whereText = " where Type=@SelectType And CleanName In (Select CleanValue from ItemValues where " + typeClause + " AND ItemId in (select guid from TypedBaseItems" + innerWhereText + "))";
+            stringBuilder.Append("))");
 
             var outerQuery = new InternalItemsQuery(query.User)
             {
@@ -5353,23 +5413,31 @@ AND Type = @InternalPersonType)");
             };
 
             var outerWhereClauses = GetWhereClauses(outerQuery, null);
-
             if (outerWhereClauses.Count != 0)
             {
-                whereText += " AND " + string.Join(" AND ", outerWhereClauses);
+                stringBuilder.Append(" AND ")
+                    .AppendJoin(" AND ", outerWhereClauses);
             }
 
-            commandText += whereText + " group by PresentationUniqueKey";
+            var whereText = stringBuilder.ToString();
+            stringBuilder.Clear();
+
+            stringBuilder.Append("select ")
+                .AppendJoin(',', columns)
+                .Append(FromText)
+                .Append(GetJoinUserDataText(query))
+                .Append(whereText)
+                .Append(" group by PresentationUniqueKey");
 
             if (query.OrderBy.Count != 0
                 || query.SimilarTo != null
                 || !string.IsNullOrEmpty(query.SearchTerm))
             {
-                commandText += GetOrderByText(query);
+                stringBuilder.Append(GetOrderByText(query));
             }
             else
             {
-                commandText += " order by SortName";
+                stringBuilder.Append(" order by SortName");
             }
 
             if (query.Limit.HasValue || query.StartIndex.HasValue)
@@ -5378,32 +5446,39 @@ AND Type = @InternalPersonType)");
 
                 if (query.Limit.HasValue || offset > 0)
                 {
-                    commandText += " LIMIT " + (query.Limit ?? int.MaxValue).ToString(CultureInfo.InvariantCulture);
+                    stringBuilder.Append(" LIMIT ")
+                        .Append(query.Limit ?? int.MaxValue);
                 }
 
                 if (offset > 0)
                 {
-                    commandText += " OFFSET " + offset.ToString(CultureInfo.InvariantCulture);
+                    stringBuilder.Append(" OFFSET ")
+                        .Append(offset);
                 }
             }
 
             var isReturningZeroItems = query.Limit.HasValue && query.Limit <= 0;
 
-            var statementTexts = new List<string>();
+            string commandText = string.Empty;
+
             if (!isReturningZeroItems)
             {
-                statementTexts.Add(commandText);
+                commandText = stringBuilder.ToString();
             }
 
+            string countText = string.Empty;
             if (query.EnableTotalRecordCount)
             {
-                var countText = "select "
-                            + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count (distinct PresentationUniqueKey)" }))
-                            + GetFromText()
-                            + GetJoinUserDataText(query)
-                            + whereText;
+                stringBuilder.Clear();
+                var columnsToSelect = new List<string> { "count (distinct PresentationUniqueKey)" };
+                SetFinalColumnsToSelect(query, columnsToSelect);
+                stringBuilder.Append("select ")
+                    .AppendJoin(',', columnsToSelect)
+                    .Append(FromText)
+                    .Append(GetJoinUserDataText(query))
+                    .Append(whereText);
 
-                statementTexts.Add(countText);
+                countText = stringBuilder.ToString();
             }
 
             var list = new List<(BaseItem, ItemCounts)>();
@@ -5413,11 +5488,9 @@ AND Type = @InternalPersonType)");
                 connection.RunInTransaction(
                     db =>
                     {
-                        var statements = PrepareAll(db, statementTexts);
-
                         if (!isReturningZeroItems)
                         {
-                            using (var statement = statements[0])
+                            using (var statement = PrepareStatement(db, commandText))
                             {
                                 statement.TryBind("@SelectType", returnType);
                                 if (EnableJoinUserData(query))
@@ -5458,13 +5531,7 @@ AND Type = @InternalPersonType)");
 
                         if (query.EnableTotalRecordCount)
                         {
-                            commandText = "select "
-                                        + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count (distinct PresentationUniqueKey)" }))
-                                        + GetFromText()
-                                        + GetJoinUserDataText(query)
-                                        + whereText;
-
-                            using (var statement = statements[statements.Length - 1])
+                            using (var statement = PrepareStatement(db, countText))
                             {
                                 statement.TryBind("@SelectType", returnType);
                                 if (EnableJoinUserData(query))
@@ -5501,7 +5568,7 @@ AND Type = @InternalPersonType)");
             return result;
         }
 
-        private static ItemCounts GetItemCounts(IReadOnlyList<IResultSetValue> reader, int countStartColumn, string[] typesToCount)
+        private static ItemCounts GetItemCounts(IReadOnlyList<ResultSetValue> reader, int countStartColumn, string[] typesToCount)
         {
             var counts = new ItemCounts();
 
@@ -5732,7 +5799,7 @@ AND Type = @InternalPersonType)");
             }
         }
 
-        private PersonInfo GetPerson(IReadOnlyList<IResultSetValue> reader)
+        private PersonInfo GetPerson(IReadOnlyList<ResultSetValue> reader)
         {
             var item = new PersonInfo
             {
@@ -5939,7 +6006,7 @@ AND Type = @InternalPersonType)");
         /// </summary>
         /// <param name="reader">The reader.</param>
         /// <returns>ChapterInfo.</returns>
-        private MediaStream GetMediaStream(IReadOnlyList<IResultSetValue> reader)
+        private MediaStream GetMediaStream(IReadOnlyList<ResultSetValue> reader)
         {
             var item = new MediaStream
             {
@@ -6240,7 +6307,7 @@ AND Type = @InternalPersonType)");
         /// </summary>
         /// <param name="reader">The reader.</param>
         /// <returns>MediaAttachment.</returns>
-        private MediaAttachment GetMediaAttachment(IReadOnlyList<IResultSetValue> reader)
+        private MediaAttachment GetMediaAttachment(IReadOnlyList<ResultSetValue> reader)
         {
             var item = new MediaAttachment
             {

Emby.Server.Implementations/Data/SqliteUserDataRepository.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -348,7 +350,7 @@ namespace Emby.Server.Implementations.Data
         /// Read a row from the specified reader into the provided userData object.
         /// </summary>
         /// <param name="reader"></param>
-        private UserItemData ReadRow(IReadOnlyList<IResultSetValue> reader)
+        private UserItemData ReadRow(IReadOnlyList<ResultSetValue> reader)
         {
             var userData = new UserItemData();
 

Emby.Server.Implementations/Data/TypeMapper.cs

@@ -13,7 +13,7 @@ namespace Emby.Server.Implementations.Data
         /// This holds all the types in the running assemblies
         /// so that we can de-serialize properly when we don't have strong types.
         /// </summary>
-        private readonly ConcurrentDictionary<string, Type> _typeMap = new ConcurrentDictionary<string, Type>();
+        private readonly ConcurrentDictionary<string, Type?> _typeMap = new ConcurrentDictionary<string, Type?>();
 
         /// <summary>
         /// Gets the type.
@@ -21,26 +21,16 @@ namespace Emby.Server.Implementations.Data
         /// <param name="typeName">Name of the type.</param>
         /// <returns>Type.</returns>
         /// <exception cref="ArgumentNullException"><c>typeName</c> is null.</exception>
-        public Type GetType(string typeName)
+        public Type? GetType(string typeName)
         {
             if (string.IsNullOrEmpty(typeName))
             {
                 throw new ArgumentNullException(nameof(typeName));
             }
 
-            return _typeMap.GetOrAdd(typeName, LookupType);
-        }
-
-        /// <summary>
-        /// Lookups the type.
-        /// </summary>
-        /// <param name="typeName">Name of the type.</param>
-        /// <returns>Type.</returns>
-        private Type LookupType(string typeName)
-        {
-            return AppDomain.CurrentDomain.GetAssemblies()
-                .Select(a => a.GetType(typeName))
-                .FirstOrDefault(t => t != null);
+            return _typeMap.GetOrAdd(typeName, k => AppDomain.CurrentDomain.GetAssemblies()
+                .Select(a => a.GetType(k))
+                .FirstOrDefault(t => t != null));
         }
     }
 }

Emby.Server.Implementations/Devices/DeviceId.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Dto/DtoService.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Emby.Server.Implementations.csproj

@@ -9,6 +9,7 @@
     <ProjectReference Include="..\Emby.Naming\Emby.Naming.csproj" />
     <ProjectReference Include="..\Emby.Notifications\Emby.Notifications.csproj" />
     <ProjectReference Include="..\Jellyfin.Api\Jellyfin.Api.csproj" />
+    <ProjectReference Include="..\Jellyfin.Server.Implementations\Jellyfin.Server.Implementations.csproj" />
     <ProjectReference Include="..\MediaBrowser.Model\MediaBrowser.Model.csproj" />
     <ProjectReference Include="..\MediaBrowser.Common\MediaBrowser.Common.csproj" />
     <ProjectReference Include="..\MediaBrowser.Controller\MediaBrowser.Controller.csproj" />
@@ -27,11 +28,11 @@
     <PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="5.0.0" />
     <PackageReference Include="Microsoft.Extensions.Configuration.Abstractions" Version="5.0.0" />
     <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="5.0.0" />
-    <PackageReference Include="Microsoft.EntityFrameworkCore.Relational" Version="5.0.6" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Relational" Version="5.0.7" />
     <PackageReference Include="Mono.Nat" Version="3.0.1" />
     <PackageReference Include="prometheus-net.DotNetRuntime" Version="4.1.0" />
-    <PackageReference Include="sharpcompress" Version="0.28.2" />
-    <PackageReference Include="SQLitePCL.pretty.netstandard" Version="2.2.0" />
+    <PackageReference Include="sharpcompress" Version="0.28.3" />
+    <PackageReference Include="SQLitePCL.pretty.netstandard" Version="3.1.0" />
     <PackageReference Include="DotNet.Glob" Version="3.1.2" />
   </ItemGroup>
 
@@ -44,6 +45,7 @@
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <TreatWarningsAsErrors Condition=" '$(Configuration)' == 'Release'">true</TreatWarningsAsErrors>
+    <Nullable>enable</Nullable>
     <!-- https://github.com/microsoft/ApplicationInsights-dotnet/issues/2047 -->
     <NoWarn>AD0001</NoWarn>
     <AnalysisMode Condition=" '$(Configuration)' == 'Debug' ">AllEnabledByDefault</AnalysisMode>

Emby.Server.Implementations/EntryPoints/ExternalPortForwarding.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -106,8 +108,6 @@ namespace Emby.Server.Implementations.EntryPoints
             NatUtility.StartDiscovery();
 
             _timer = new Timer((_) => _createdRules.Clear(), null, TimeSpan.FromMinutes(10), TimeSpan.FromMinutes(10));
-
-            _deviceDiscovery.DeviceDiscovered += OnDeviceDiscoveryDeviceDiscovered;
         }
 
         private void Stop()
@@ -118,13 +118,6 @@ namespace Emby.Server.Implementations.EntryPoints
             NatUtility.DeviceFound -= OnNatUtilityDeviceFound;
 
             _timer?.Dispose();
-
-            _deviceDiscovery.DeviceDiscovered -= OnDeviceDiscoveryDeviceDiscovered;
-        }
-
-        private void OnDeviceDiscoveryDeviceDiscovered(object sender, GenericEventArgs<UpnpDeviceInfo> e)
-        {
-            NatUtility.Search(e.Argument.LocalIpAddress, NatProtocol.Upnp);
         }
 
         private async void OnNatUtilityDeviceFound(object sender, DeviceEventArgs e)

Emby.Server.Implementations/EntryPoints/LibraryChangedNotifier.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/EntryPoints/RecordingNotifier.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/EntryPoints/UdpServerEntryPoint.cs

@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Net.Sockets;
 using System.Threading;
@@ -56,8 +54,8 @@ namespace Emby.Server.Implementations.EntryPoints
 
             try
             {
-                _udpServer = new UdpServer(_logger, _appHost, _config);
-                _udpServer.Start(PortNumber, _cancellationTokenSource.Token);
+                _udpServer = new UdpServer(_logger, _appHost, _config, PortNumber);
+                _udpServer.Start(_cancellationTokenSource.Token);
             }
             catch (SocketException ex)
             {

Emby.Server.Implementations/EntryPoints/UserDataChangeNotifier.cs

@@ -26,7 +26,7 @@ namespace Emby.Server.Implementations.EntryPoints
         private readonly Dictionary<Guid, List<BaseItem>> _changedItems = new Dictionary<Guid, List<BaseItem>>();
 
         private readonly object _syncLock = new object();
-        private Timer _updateTimer;
+        private Timer? _updateTimer;
 
         public UserDataChangeNotifier(IUserDataManager userDataManager, ISessionManager sessionManager, IUserManager userManager)
         {
@@ -42,7 +42,7 @@ namespace Emby.Server.Implementations.EntryPoints
             return Task.CompletedTask;
         }
 
-        void OnUserDataManagerUserDataSaved(object sender, UserDataSaveEventArgs e)
+        private void OnUserDataManagerUserDataSaved(object? sender, UserDataSaveEventArgs e)
         {
             if (e.SaveReason == UserDataSaveReason.PlaybackProgress)
             {
@@ -64,7 +64,7 @@ namespace Emby.Server.Implementations.EntryPoints
                     _updateTimer.Change(UpdateDuration, Timeout.Infinite);
                 }
 
-                if (!_changedItems.TryGetValue(e.UserId, out List<BaseItem> keys))
+                if (!_changedItems.TryGetValue(e.UserId, out List<BaseItem>? keys))
                 {
                     keys = new List<BaseItem>();
                     _changedItems[e.UserId] = keys;
@@ -87,7 +87,7 @@ namespace Emby.Server.Implementations.EntryPoints
             }
         }
 
-        private void UpdateTimerCallback(object state)
+        private void UpdateTimerCallback(object? state)
         {
             lock (_syncLock)
             {

Emby.Server.Implementations/HttpServer/Security/SessionContext.cs

@@ -43,14 +43,14 @@ namespace Emby.Server.Implementations.HttpServer.Security
             return GetSession((HttpContext)requestContext);
         }
 
-        public async Task<User> GetUser(HttpContext requestContext)
+        public async Task<User?> GetUser(HttpContext requestContext)
         {
             var session = await GetSession(requestContext).ConfigureAwait(false);
 
             return session == null || session.UserId.Equals(Guid.Empty) ? null : _userManager.GetUserById(session.UserId);
         }
 
-        public Task<User> GetUser(object requestContext)
+        public Task<User?> GetUser(object requestContext)
         {
             return GetUser(((HttpRequest)requestContext).HttpContext);
         }

Emby.Server.Implementations/HttpServer/WebSocketConnection.cs

@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Buffers;
 using System.IO.Pipelines;

Emby.Server.Implementations/HttpServer/WebSocketManager.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/IO/FileRefresher.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/IO/LibraryMonitor.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/IO/ManagedFileSystem.cs

@@ -7,6 +7,7 @@ using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
 using MediaBrowser.Common.Configuration;
+using MediaBrowser.Common.Extensions;
 using MediaBrowser.Model.IO;
 using MediaBrowser.Model.System;
 using Microsoft.Extensions.Logging;
@@ -61,7 +62,7 @@ namespace Emby.Server.Implementations.IO
         /// <param name="filename">The filename.</param>
         /// <returns>System.String.</returns>
         /// <exception cref="ArgumentNullException">filename</exception>
-        public virtual string ResolveShortcut(string filename)
+        public virtual string? ResolveShortcut(string filename)
         {
             if (string.IsNullOrEmpty(filename))
             {
@@ -243,8 +244,8 @@ namespace Emby.Server.Implementations.IO
                 {
                     result.Length = fileInfo.Length;
 
-                    // Issue #2354 get the size of files behind symbolic links
-                    if (fileInfo.Attributes.HasFlag(FileAttributes.ReparsePoint))
+                    // Issue #2354 get the size of files behind symbolic links. Also Enum.HasFlag is bad as it boxes!
+                    if ((fileInfo.Attributes & FileAttributes.ReparsePoint) == FileAttributes.ReparsePoint)
                     {
                         try
                         {
@@ -601,7 +602,7 @@ namespace Emby.Server.Implementations.IO
             return GetFiles(path, null, false, recursive);
         }
 
-        public virtual IEnumerable<FileSystemMetadata> GetFiles(string path, IReadOnlyList<string> extensions, bool enableCaseSensitiveExtensions, bool recursive = false)
+        public virtual IEnumerable<FileSystemMetadata> GetFiles(string path, IReadOnlyList<string>? extensions, bool enableCaseSensitiveExtensions, bool recursive = false)
         {
             var enumerationOptions = GetEnumerationOptions(recursive);
 
@@ -618,13 +619,13 @@ namespace Emby.Server.Implementations.IO
             {
                 files = files.Where(i =>
                 {
-                    var ext = i.Extension;
-                    if (ext == null)
+                    var ext = i.Extension.AsSpan();
+                    if (ext.IsEmpty)
                     {
                         return false;
                     }
 
-                    return extensions.Contains(ext, StringComparer.OrdinalIgnoreCase);
+                    return extensions.Contains(ext, StringComparison.OrdinalIgnoreCase);
                 });
             }
 
@@ -636,8 +637,7 @@ namespace Emby.Server.Implementations.IO
             var directoryInfo = new DirectoryInfo(path);
             var enumerationOptions = GetEnumerationOptions(recursive);
 
-            return ToMetadata(directoryInfo.EnumerateDirectories("*", enumerationOptions))
-                .Concat(ToMetadata(directoryInfo.EnumerateFiles("*", enumerationOptions)));
+            return ToMetadata(directoryInfo.EnumerateFileSystemInfos("*", enumerationOptions));
         }
 
         private IEnumerable<FileSystemMetadata> ToMetadata(IEnumerable<FileSystemInfo> infos)
@@ -655,7 +655,7 @@ namespace Emby.Server.Implementations.IO
             return GetFilePaths(path, null, false, recursive);
         }
 
-        public virtual IEnumerable<string> GetFilePaths(string path, string[] extensions, bool enableCaseSensitiveExtensions, bool recursive = false)
+        public virtual IEnumerable<string> GetFilePaths(string path, string[]? extensions, bool enableCaseSensitiveExtensions, bool recursive = false)
         {
             var enumerationOptions = GetEnumerationOptions(recursive);
 
@@ -672,13 +672,13 @@ namespace Emby.Server.Implementations.IO
             {
                 files = files.Where(i =>
                 {
-                    var ext = Path.GetExtension(i);
-                    if (ext == null)
+                    var ext = Path.GetExtension(i.AsSpan());
+                    if (ext.IsEmpty)
                     {
                         return false;
                     }
 
-                    return extensions.Contains(ext, StringComparer.OrdinalIgnoreCase);
+                    return extensions.Contains(ext, StringComparison.OrdinalIgnoreCase);
                 });
             }
 

Emby.Server.Implementations/IO/MbLinkShortcutHandler.cs

@@ -17,7 +17,7 @@ namespace Emby.Server.Implementations.IO
 
         public string Extension => ".mblink";
 
-        public string Resolve(string shortcutPath)
+        public string? Resolve(string shortcutPath)
         {
             if (string.IsNullOrEmpty(shortcutPath))
             {

Emby.Server.Implementations/IO/StreamHelper.cs

@@ -11,7 +11,7 @@ namespace Emby.Server.Implementations.IO
 {
     public class StreamHelper : IStreamHelper
     {
-        public async Task CopyToAsync(Stream source, Stream destination, int bufferSize, Action onStarted, CancellationToken cancellationToken)
+        public async Task CopyToAsync(Stream source, Stream destination, int bufferSize, Action? onStarted, CancellationToken cancellationToken)
         {
             byte[] buffer = ArrayPool<byte>.Shared.Rent(bufferSize);
             try

Emby.Server.Implementations/IStartupOptions.cs

@@ -1,5 +1,4 @@
 #pragma warning disable CS1591
-#nullable enable
 
 namespace Emby.Server.Implementations
 {

Emby.Server.Implementations/Images/BaseDynamicImageProvider.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Images/CollectionFolderImageProvider.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Images/DynamicImageProvider.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Images/FolderImageProvider.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System.Collections.Generic;

Emby.Server.Implementations/Images/GenreImageProvider.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System.Collections.Generic;

Emby.Server.Implementations/Images/PlaylistImageProvider.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System.Collections.Generic;

Emby.Server.Implementations/Library/CoreResolutionIgnoreRule.cs

@@ -77,7 +77,7 @@ namespace Emby.Server.Implementations.Library
                 if (parent != null)
                 {
                     // Don't resolve these into audio files
-                    if (string.Equals(Path.GetFileNameWithoutExtension(filename), BaseItem.ThemeSongFilename, StringComparison.Ordinal)
+                    if (Path.GetFileNameWithoutExtension(filename.AsSpan()).Equals(BaseItem.ThemeSongFilename, StringComparison.Ordinal)
                         && _libraryManager.IsAudioFile(filename))
                     {
                         return true;

Emby.Server.Implementations/Library/ExclusiveLiveStream.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Library/IgnorePatterns.cs

@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Linq;
 using DotNet.Globbing;

Emby.Server.Implementations/Library/LibraryManager.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -694,25 +696,32 @@ namespace Emby.Server.Implementations.Library
         }
 
         private IEnumerable<BaseItem> ResolveFileList(
-            IEnumerable<FileSystemMetadata> fileList,
+            IReadOnlyList<FileSystemMetadata> fileList,
             IDirectoryService directoryService,
             Folder parent,
             string collectionType,
             IItemResolver[] resolvers,
             LibraryOptions libraryOptions)
         {
-            return fileList.Select(f =>
+            // Given that fileList is a list we can save enumerator allocations by indexing
+            for (var i = 0; i < fileList.Count; i++)
             {
+                var file = fileList[i];
+                BaseItem result = null;
                 try
                 {
-                    return ResolvePath(f, directoryService, resolvers, parent, collectionType, libraryOptions);
+                    result = ResolvePath(file, directoryService, resolvers, parent, collectionType, libraryOptions);
                 }
                 catch (Exception ex)
                 {
-                    _logger.LogError(ex, "Error resolving path {path}", f.FullName);
-                    return null;
+                    _logger.LogError(ex, "Error resolving path {Path}", file.FullName);
                 }
-            }).Where(i => i != null);
+
+                if (result != null)
+                {
+                    yield return result;
+                }
+            }
         }
 
         /// <summary>
@@ -1063,17 +1072,17 @@ namespace Emby.Server.Implementations.Library
             // Start by just validating the children of the root, but go no further
             await RootFolder.ValidateChildren(
                 new SimpleProgress<double>(),
-                cancellationToken,
                 new MetadataRefreshOptions(new DirectoryService(_fileSystem)),
-                recursive: false).ConfigureAwait(false);
+                recursive: false,
+                cancellationToken).ConfigureAwait(false);
 
             await GetUserRootFolder().RefreshMetadata(cancellationToken).ConfigureAwait(false);
 
             await GetUserRootFolder().ValidateChildren(
                 new SimpleProgress<double>(),
-                cancellationToken,
                 new MetadataRefreshOptions(new DirectoryService(_fileSystem)),
-                recursive: false).ConfigureAwait(false);
+                recursive: false,
+                cancellationToken).ConfigureAwait(false);
 
             // Quickly scan CollectionFolders for changes
             foreach (var folder in GetUserRootFolder().Children.OfType<Folder>())
@@ -1093,7 +1102,7 @@ namespace Emby.Server.Implementations.Library
             innerProgress.RegisterAction(pct => progress.Report(pct * 0.96));
 
             // Validate the entire media library
-            await RootFolder.ValidateChildren(innerProgress, cancellationToken, new MetadataRefreshOptions(new DirectoryService(_fileSystem)), recursive: true).ConfigureAwait(false);
+            await RootFolder.ValidateChildren(innerProgress, new MetadataRefreshOptions(new DirectoryService(_fileSystem)), recursive: true, cancellationToken).ConfigureAwait(false);
 
             progress.Report(96);
 
@@ -2074,7 +2083,7 @@ namespace Emby.Server.Implementations.Library
                 return new List<Folder>();
             }
 
-            return GetCollectionFoldersInternal(item, GetUserRootFolder().Children.OfType<Folder>().ToList());
+            return GetCollectionFoldersInternal(item, GetUserRootFolder().Children.OfType<Folder>());
         }
 
         public List<Folder> GetCollectionFolders(BaseItem item, List<Folder> allUserRootChildren)
@@ -2099,10 +2108,10 @@ namespace Emby.Server.Implementations.Library
             return GetCollectionFoldersInternal(item, allUserRootChildren);
         }
 
-        private static List<Folder> GetCollectionFoldersInternal(BaseItem item, List<Folder> allUserRootChildren)
+        private static List<Folder> GetCollectionFoldersInternal(BaseItem item, IEnumerable<Folder> allUserRootChildren)
         {
             return allUserRootChildren
-                .Where(i => string.Equals(i.Path, item.Path, StringComparison.OrdinalIgnoreCase) || i.PhysicalLocations.Contains(item.Path, StringComparer.OrdinalIgnoreCase))
+                .Where(i => string.Equals(i.Path, item.Path, StringComparison.OrdinalIgnoreCase) || i.PhysicalLocations.Contains(item.Path.AsSpan(), StringComparison.OrdinalIgnoreCase))
                 .ToList();
         }
 
@@ -2110,9 +2119,9 @@ namespace Emby.Server.Implementations.Library
         {
             if (!(item is CollectionFolder collectionFolder))
             {
+                // List.Find is more performant than FirstOrDefault due to enumerator allocation
                 collectionFolder = GetCollectionFolders(item)
-                   .OfType<CollectionFolder>()
-                   .FirstOrDefault();
+                    .Find(folder => folder is CollectionFolder) as CollectionFolder;
             }
 
             return collectionFolder == null ? new LibraryOptions() : collectionFolder.GetLibraryOptions();
@@ -2498,8 +2507,7 @@ namespace Emby.Server.Implementations.Library
         /// <inheritdoc />
         public bool IsVideoFile(string path)
         {
-            var resolver = new VideoResolver(GetNamingOptions());
-            return resolver.IsVideoFile(path);
+            return VideoResolver.IsVideoFile(path, GetNamingOptions());
         }
 
         /// <inheritdoc />
@@ -2677,6 +2685,7 @@ namespace Emby.Server.Implementations.Library
             return changed;
         }
 
+        /// <inheritdoc />
         public NamingOptions GetNamingOptions()
         {
             if (_namingOptions == null)
@@ -2690,13 +2699,12 @@ namespace Emby.Server.Implementations.Library
 
         public ItemLookupInfo ParseName(string name)
         {
-            var resolver = new VideoResolver(GetNamingOptions());
-
-            var result = resolver.CleanDateTime(name);
+            var namingOptions = GetNamingOptions();
+            var result = VideoResolver.CleanDateTime(name, namingOptions);
 
             return new ItemLookupInfo
             {
-                Name = resolver.TryCleanString(result.Name, out var newName) ? newName.ToString() : result.Name,
+                Name = VideoResolver.TryCleanString(result.Name, namingOptions, out var newName) ? newName.ToString() : result.Name,
                 Year = result.Year
             };
         }
@@ -2710,9 +2718,7 @@ namespace Emby.Server.Implementations.Library
                 .SelectMany(i => _fileSystem.GetFiles(i.FullName, _videoFileExtensions, false, false))
                 .ToList();
 
-            var videoListResolver = new VideoListResolver(namingOptions);
-
-            var videos = videoListResolver.Resolve(fileSystemChildren);
+            var videos = VideoListResolver.Resolve(fileSystemChildren, namingOptions);
 
             var currentVideo = videos.FirstOrDefault(i => string.Equals(owner.Path, i.Files[0].Path, StringComparison.OrdinalIgnoreCase));
 
@@ -2756,9 +2762,7 @@ namespace Emby.Server.Implementations.Library
                 .SelectMany(i => _fileSystem.GetFiles(i.FullName, _videoFileExtensions, false, false))
                 .ToList();
 
-            var videoListResolver = new VideoListResolver(namingOptions);
-
-            var videos = videoListResolver.Resolve(fileSystemChildren);
+            var videos = VideoListResolver.Resolve(fileSystemChildren, namingOptions);
 
             var currentVideo = videos.FirstOrDefault(i => string.Equals(owner.Path, i.Files[0].Path, StringComparison.OrdinalIgnoreCase));
 

Emby.Server.Implementations/Library/LiveStreamHelper.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Library/MediaSourceManager.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -350,7 +352,7 @@ namespace Emby.Server.Implementations.Library
 
         private string[] NormalizeLanguage(string language)
         {
-            if (language == null)
+            if (string.IsNullOrEmpty(language))
             {
                 return Array.Empty<string>();
             }
@@ -379,8 +381,7 @@ namespace Emby.Server.Implementations.Library
                 }
             }
 
-            var preferredSubs = string.IsNullOrEmpty(user.SubtitleLanguagePreference)
-                ? Array.Empty<string>() : NormalizeLanguage(user.SubtitleLanguagePreference);
+            var preferredSubs = NormalizeLanguage(user.SubtitleLanguagePreference);
 
             var defaultAudioIndex = source.DefaultAudioStreamIndex;
             var audioLangage = defaultAudioIndex == null
@@ -409,9 +410,7 @@ namespace Emby.Server.Implementations.Library
                 }
             }
 
-            var preferredAudio = string.IsNullOrEmpty(user.AudioLanguagePreference)
-                ? Array.Empty<string>()
-                : NormalizeLanguage(user.AudioLanguagePreference);
+            var preferredAudio = NormalizeLanguage(user.AudioLanguagePreference);
 
             source.DefaultAudioStreamIndex = MediaStreamSelector.GetDefaultAudioStreamIndex(source.MediaStreams, preferredAudio, user.PlayDefaultAudioTrack);
         }

Emby.Server.Implementations/Library/MediaStreamSelector.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Library/MusicManager.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Library/PathExtensions.cs

@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Diagnostics.CodeAnalysis;
 using MediaBrowser.Common.Providers;

Emby.Server.Implementations/Library/ResolverHelper.cs

@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.IO;
 using System.Linq;

Emby.Server.Implementations/Library/Resolvers/Audio/AudioResolver.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Library/Resolvers/Audio/MusicAlbumResolver.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Collections.Generic;
 using System.Linq;

Emby.Server.Implementations/Library/Resolvers/Audio/MusicArtistResolver.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Linq;
 using System.Threading.Tasks;

Emby.Server.Implementations/Library/Resolvers/BaseVideoResolver.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -45,11 +47,9 @@ namespace Emby.Server.Implementations.Library.Resolvers
         protected virtual TVideoType ResolveVideo<TVideoType>(ItemResolveArgs args, bool parseName)
               where TVideoType : Video, new()
         {
-            var namingOptions = ((LibraryManager)LibraryManager).GetNamingOptions();
+            var namingOptions = LibraryManager.GetNamingOptions();
 
             // If the path is a file check for a matching extensions
-            var parser = new VideoResolver(namingOptions);
-
             if (args.IsDirectory)
             {
                 TVideoType video = null;
@@ -64,7 +64,7 @@ namespace Emby.Server.Implementations.Library.Resolvers
                     {
                         if (IsDvdDirectory(child.FullName, filename, args.DirectoryService))
                         {
-                            videoInfo = parser.ResolveDirectory(args.Path);
+                            videoInfo = VideoResolver.ResolveDirectory(args.Path, namingOptions);
 
                             if (videoInfo == null)
                             {
@@ -82,7 +82,7 @@ namespace Emby.Server.Implementations.Library.Resolvers
 
                         if (IsBluRayDirectory(child.FullName, filename, args.DirectoryService))
                         {
-                            videoInfo = parser.ResolveDirectory(args.Path);
+                            videoInfo = VideoResolver.ResolveDirectory(args.Path, namingOptions);
 
                             if (videoInfo == null)
                             {
@@ -100,7 +100,7 @@ namespace Emby.Server.Implementations.Library.Resolvers
                     }
                     else if (IsDvdFile(filename))
                     {
-                        videoInfo = parser.ResolveDirectory(args.Path);
+                        videoInfo = VideoResolver.ResolveDirectory(args.Path, namingOptions);
 
                         if (videoInfo == null)
                         {
@@ -130,7 +130,7 @@ namespace Emby.Server.Implementations.Library.Resolvers
             }
             else
             {
-                var videoInfo = parser.Resolve(args.Path, false, false);
+                var videoInfo = VideoResolver.Resolve(args.Path, false, namingOptions, false);
 
                 if (videoInfo == null)
                 {
@@ -250,10 +250,7 @@ namespace Emby.Server.Implementations.Library.Resolvers
 
         protected void Set3DFormat(Video video)
         {
-            var namingOptions = ((LibraryManager)LibraryManager).GetNamingOptions();
-
-            var resolver = new Format3DParser(namingOptions);
-            var result = resolver.Parse(video.Path);
+            var result = Format3DParser.Parse(video.Path, LibraryManager.GetNamingOptions());
 
             Set3DFormat(video, result.Is3D, result.Format3D);
         }

Emby.Server.Implementations/Library/Resolvers/Books/BookResolver.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Library/Resolvers/FolderResolver.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Library;
 using MediaBrowser.Controller.Resolvers;

Emby.Server.Implementations/Library/Resolvers/ItemResolver.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Library;
 using MediaBrowser.Controller.Resolvers;

Emby.Server.Implementations/Library/Resolvers/Movies/BoxSetResolver.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.IO;
 using MediaBrowser.Controller.Entities;

Emby.Server.Implementations/Library/Resolvers/Movies/MovieResolver.cs

@@ -1,9 +1,12 @@
+#nullable disable
+
 using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Text.RegularExpressions;
 using Emby.Naming.Video;
+using MediaBrowser.Common.Extensions;
 using MediaBrowser.Controller.Drawing;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Entities.Movies;
@@ -255,10 +258,9 @@ namespace Emby.Server.Implementations.Library.Resolvers.Movies
                 }
             }
 
-            var namingOptions = ((LibraryManager)LibraryManager).GetNamingOptions();
+            var namingOptions = LibraryManager.GetNamingOptions();
 
-            var resolver = new VideoListResolver(namingOptions);
-            var resolverResult = resolver.Resolve(files, suppportMultiEditions).ToList();
+            var resolverResult = VideoListResolver.Resolve(files, namingOptions, suppportMultiEditions).ToList();
 
             var result = new MultiItemResolverResult
             {
@@ -535,7 +537,7 @@ namespace Emby.Server.Implementations.Library.Resolvers.Movies
             return returnVideo;
         }
 
-        private bool IsInvalid(Folder parent, string collectionType)
+        private bool IsInvalid(Folder parent, ReadOnlySpan<char> collectionType)
         {
             if (parent != null)
             {
@@ -545,12 +547,12 @@ namespace Emby.Server.Implementations.Library.Resolvers.Movies
                 }
             }
 
-            if (string.IsNullOrEmpty(collectionType))
+            if (collectionType.IsEmpty)
             {
                 return false;
             }
 
-            return !_validCollectionTypes.Contains(collectionType, StringComparer.OrdinalIgnoreCase);
+            return !_validCollectionTypes.Contains(collectionType, StringComparison.OrdinalIgnoreCase);
         }
     }
 }

Emby.Server.Implementations/Library/Resolvers/PhotoAlbumResolver.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using MediaBrowser.Controller.Drawing;
 using MediaBrowser.Controller.Entities;

Emby.Server.Implementations/Library/Resolvers/PhotoResolver.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Library/Resolvers/PlaylistResolver.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Library/Resolvers/SpecialFolderResolver.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Library/Resolvers/TV/EpisodeResolver.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Linq;
 using MediaBrowser.Controller.Entities;

Emby.Server.Implementations/Library/Resolvers/TV/SeasonResolver.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System.Globalization;
 using Emby.Naming.TV;
 using MediaBrowser.Controller.Entities.TV;

Emby.Server.Implementations/Library/Resolvers/TV/SeriesResolver.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Library/Resolvers/VideoResolver.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using MediaBrowser.Controller.Entities;

Emby.Server.Implementations/Library/SearchEngine.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Library/UserDataManager.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -220,7 +222,7 @@ namespace Emby.Server.Implementations.Library
             var hasRuntime = runtimeTicks > 0;
 
             // If a position has been reported, and if we know the duration
-            if (positionTicks > 0 && hasRuntime && !(item is AudioBook))
+            if (positionTicks > 0 && hasRuntime && item is not AudioBook && item is not Book)
             {
                 var pctIn = decimal.Divide(positionTicks, runtimeTicks) * 100;
 
@@ -239,7 +241,7 @@ namespace Emby.Server.Implementations.Library
                 {
                     // Enforce MinResumeDuration
                     var durationSeconds = TimeSpan.FromTicks(runtimeTicks).TotalSeconds;
-                    if (durationSeconds < _config.Configuration.MinResumeDurationSeconds && !(item is Book))
+                    if (durationSeconds < _config.Configuration.MinResumeDurationSeconds)
                     {
                         positionTicks = 0;
                         data.Played = playedToCompletion = true;

Emby.Server.Implementations/Library/UserViewManager.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/LiveTv/EmbyTV/DirectRecorder.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/LiveTv/EmbyTV/EmbyTV.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/LiveTv/EmbyTV/EncodedRecorder.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/LiveTv/EmbyTV/EpgChannelData.cs

@@ -6,7 +6,6 @@ using MediaBrowser.Controller.LiveTv;
 
 namespace Emby.Server.Implementations.LiveTv.EmbyTV
 {
-
     internal class EpgChannelData
     {
 
@@ -39,13 +38,13 @@ namespace Emby.Server.Implementations.LiveTv.EmbyTV
             }
         }
 
-        public ChannelInfo GetChannelById(string id)
+        public ChannelInfo? GetChannelById(string id)
             => _channelsById.GetValueOrDefault(id);
 
-        public ChannelInfo GetChannelByNumber(string number)
+        public ChannelInfo? GetChannelByNumber(string number)
             => _channelsByNumber.GetValueOrDefault(number);
 
-        public ChannelInfo GetChannelByName(string name)
+        public ChannelInfo? GetChannelByName(string name)
             => _channelsByName.GetValueOrDefault(name);
 
         public static string NormalizeName(string value)

Emby.Server.Implementations/LiveTv/EmbyTV/ItemDataProvider.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/LiveTv/EmbyTV/TimerManager.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/LiveTv/Listings/SchedulesDirect.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/LiveTv/Listings/XmlTvListingsProvider.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/LiveTv/LiveTvConfigurationFactory.cs

@@ -1,21 +1,23 @@
-#pragma warning disable CS1591
-
 using System.Collections.Generic;
 using MediaBrowser.Common.Configuration;
 using MediaBrowser.Model.LiveTv;
 
 namespace Emby.Server.Implementations.LiveTv
 {
+    /// <summary>
+    /// <see cref="IConfigurationFactory" /> implementation for <see cref="LiveTvOptions" />.
+    /// </summary>
     public class LiveTvConfigurationFactory : IConfigurationFactory
     {
+        /// <inheritdoc />
         public IEnumerable<ConfigurationStore> GetConfigurations()
         {
             return new ConfigurationStore[]
             {
                 new ConfigurationStore
                 {
-                     ConfigurationType = typeof(LiveTvOptions),
-                     Key = "livetv"
+                    ConfigurationType = typeof(LiveTvOptions),
+                    Key = "livetv"
                 }
             };
         }

Emby.Server.Implementations/LiveTv/LiveTvDtoService.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/LiveTv/LiveTvManager.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -2264,7 +2266,7 @@ namespace Emby.Server.Implementations.LiveTv
 
             if (dataSourceChanged)
             {
-                _taskManager.CancelIfRunningAndQueue<RefreshChannelsScheduledTask>();
+                _taskManager.CancelIfRunningAndQueue<RefreshGuideScheduledTask>();
             }
 
             return info;
@@ -2307,7 +2309,7 @@ namespace Emby.Server.Implementations.LiveTv
 
             _config.SaveConfiguration("livetv", config);
 
-            _taskManager.CancelIfRunningAndQueue<RefreshChannelsScheduledTask>();
+            _taskManager.CancelIfRunningAndQueue<RefreshGuideScheduledTask>();
 
             return info;
         }
@@ -2319,7 +2321,7 @@ namespace Emby.Server.Implementations.LiveTv
             config.ListingProviders = config.ListingProviders.Where(i => !string.Equals(id, i.Id, StringComparison.OrdinalIgnoreCase)).ToArray();
 
             _config.SaveConfiguration("livetv", config);
-            _taskManager.CancelIfRunningAndQueue<RefreshChannelsScheduledTask>();
+            _taskManager.CancelIfRunningAndQueue<RefreshGuideScheduledTask>();
         }
 
         public async Task<TunerChannelMapping> SetChannelMapping(string providerId, string tunerChannelId, string providerChannelId)
@@ -2353,7 +2355,7 @@ namespace Emby.Server.Implementations.LiveTv
             var tunerChannelMappings =
                 tunerChannels.Select(i => GetTunerChannelMapping(i, mappings, providerChannels)).ToList();
 
-            _taskManager.CancelIfRunningAndQueue<RefreshChannelsScheduledTask>();
+            _taskManager.CancelIfRunningAndQueue<RefreshGuideScheduledTask>();
 
             return tunerChannelMappings.First(i => string.Equals(i.Id, tunerChannelId, StringComparison.OrdinalIgnoreCase));
         }

Emby.Server.Implementations/LiveTv/LiveTvMediaSourceProvider.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/LiveTv/RefreshGuideScheduledTask.cs

@@ -1,7 +1,6 @@
-#pragma warning disable CS1591
-
 using System;
 using System.Collections.Generic;
+using System.Threading;
 using System.Threading.Tasks;
 using MediaBrowser.Common.Configuration;
 using MediaBrowser.Controller.LiveTv;
@@ -10,34 +9,55 @@ using MediaBrowser.Model.Tasks;
 
 namespace Emby.Server.Implementations.LiveTv
 {
-    public class RefreshChannelsScheduledTask : IScheduledTask, IConfigurableScheduledTask
+    /// <summary>
+    /// The "Refresh Guide" scheduled task.
+    /// </summary>
+    public class RefreshGuideScheduledTask : IScheduledTask, IConfigurableScheduledTask
     {
         private readonly ILiveTvManager _liveTvManager;
         private readonly IConfigurationManager _config;
 
-        public RefreshChannelsScheduledTask(ILiveTvManager liveTvManager, IConfigurationManager config)
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RefreshGuideScheduledTask"/> class.
+        /// </summary>
+        /// <param name="liveTvManager">The live tv manager.</param>
+        /// <param name="config">The configuration manager.</param>
+        public RefreshGuideScheduledTask(ILiveTvManager liveTvManager, IConfigurationManager config)
         {
             _liveTvManager = liveTvManager;
             _config = config;
         }
 
+        /// <inheritdoc />
         public string Name => "Refresh Guide";
 
+        /// <inheritdoc />
         public string Description => "Downloads channel information from live tv services.";
 
+        /// <inheritdoc />
         public string Category => "Live TV";
 
-        public Task Execute(System.Threading.CancellationToken cancellationToken, IProgress<double> progress)
+        /// <inheritdoc />
+        public bool IsHidden => _liveTvManager.Services.Count == 1 && GetConfiguration().TunerHosts.Length == 0;
+
+        /// <inheritdoc />
+        public bool IsEnabled => true;
+
+        /// <inheritdoc />
+        public bool IsLogged => true;
+
+        /// <inheritdoc />
+        public string Key => "RefreshGuide";
+
+        /// <inheritdoc />
+        public Task Execute(CancellationToken cancellationToken, IProgress<double> progress)
         {
             var manager = (LiveTvManager)_liveTvManager;
 
             return manager.RefreshChannels(progress, cancellationToken);
         }
 
-        /// <summary>
-        /// Creates the triggers that define when the task will run.
-        /// </summary>
-        /// <returns>IEnumerable{BaseTaskTrigger}.</returns>
+        /// <inheritdoc />
         public IEnumerable<TaskTriggerInfo> GetDefaultTriggers()
         {
             return new[]
@@ -51,13 +71,5 @@ namespace Emby.Server.Implementations.LiveTv
         {
             return _config.GetConfiguration<LiveTvOptions>("livetv");
         }
-
-        public bool IsHidden => _liveTvManager.Services.Count == 1 && GetConfiguration().TunerHosts.Length == 0;
-
-        public bool IsEnabled => true;
-
-        public bool IsLogged => true;
-
-        public string Key => "RefreshGuide";
     }
 }

Emby.Server.Implementations/LiveTv/TunerHosts/BaseTunerHost.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -38,6 +40,7 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
         public virtual bool IsSupported => true;
 
         protected abstract Task<List<ChannelInfo>> GetChannelsInternal(TunerHostInfo tuner, CancellationToken cancellationToken);
+
         public abstract string Type { get; }
 
         public async Task<List<ChannelInfo>> GetChannels(TunerHostInfo tuner, bool enableCache, CancellationToken cancellationToken)

Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/Channels.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
 {
     internal class Channels

Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/DiscoverResponse.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 
 namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun

Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunHost.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -581,7 +583,6 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
                     Logger,
                     Config,
                     _appHost,
-                    _networkManager,
                     _streamHelper);
             }
 
@@ -622,7 +623,6 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
                 Logger,
                 Config,
                 _appHost,
-                _networkManager,
                 _streamHelper);
         }
 

Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunManager.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunUdpStream.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -10,7 +12,6 @@ using System.Net.Sockets;
 using System.Threading;
 using System.Threading.Tasks;
 using MediaBrowser.Common.Configuration;
-using MediaBrowser.Common.Net;
 using MediaBrowser.Controller;
 using MediaBrowser.Controller.Library;
 using MediaBrowser.Model.Dto;
@@ -28,7 +29,6 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
         private readonly IServerApplicationHost _appHost;
         private readonly IHdHomerunChannelCommands _channelCommands;
         private readonly int _numTuners;
-        private readonly INetworkManager _networkManager;
 
         public HdHomerunUdpStream(
             MediaSourceInfo mediaSource,
@@ -40,12 +40,10 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
             ILogger logger,
             IConfigurationManager configurationManager,
             IServerApplicationHost appHost,
-            INetworkManager networkManager,
             IStreamHelper streamHelper)
             : base(mediaSource, tunerHostInfo, fileSystem, logger, configurationManager, streamHelper)
         {
             _appHost = appHost;
-            _networkManager = networkManager;
             OriginalStreamId = originalStreamId;
             _channelCommands = channelCommands;
             _numTuners = numTuners;
@@ -126,7 +124,7 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
                 using (udpClient)
                 using (hdHomerunManager)
                 {
-                    if (!(ex is OperationCanceledException))
+                    if (ex is not OperationCanceledException)
                     {
                         Logger.LogError(ex, "Error opening live stream:");
                     }

Emby.Server.Implementations/LiveTv/TunerHosts/LiveStream.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/LiveTv/TunerHosts/M3UTunerHost.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -27,6 +29,14 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
 {
     public class M3UTunerHost : BaseTunerHost, ITunerHost, IConfigurableTunerHost
     {
+        private static readonly string[] _disallowedSharedStreamExtensions =
+        {
+            ".mkv",
+            ".mp4",
+            ".m3u8",
+            ".mpd"
+        };
+
         private readonly IHttpClientFactory _httpClientFactory;
         private readonly IServerApplicationHost _appHost;
         private readonly INetworkManager _networkManager;
@@ -65,7 +75,7 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
         {
             var channelIdPrefix = GetFullChannelIdPrefix(info);
 
-            return await new M3uParser(Logger, _httpClientFactory, _appHost)
+            return await new M3uParser(Logger, _httpClientFactory)
                 .Parse(info, channelIdPrefix, cancellationToken)
                 .ConfigureAwait(false);
         }
@@ -86,14 +96,6 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
             return Task.FromResult(list);
         }
 
-        private static readonly string[] _disallowedSharedStreamExtensions =
-        {
-            ".mkv",
-            ".mp4",
-            ".m3u8",
-            ".mpd"
-        };
-
         protected override async Task<ILiveStream> GetChannelStream(TunerHostInfo info, ChannelInfo channelInfo, string streamId, List<ILiveStream> currentLiveStreams, CancellationToken cancellationToken)
         {
             var tunerCount = info.TunerCount;
@@ -128,7 +130,7 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
 
         public async Task Validate(TunerHostInfo info)
         {
-            using (var stream = await new M3uParser(Logger, _httpClientFactory, _appHost).GetListingsStream(info, CancellationToken.None).ConfigureAwait(false))
+            using (var stream = await new M3uParser(Logger, _httpClientFactory).GetListingsStream(info, CancellationToken.None).ConfigureAwait(false))
             {
             }
         }

Emby.Server.Implementations/LiveTv/TunerHosts/M3uParser.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -19,15 +21,15 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
 {
     public class M3uParser
     {
+        private const string ExtInfPrefix = "#EXTINF:";
+
         private readonly ILogger _logger;
         private readonly IHttpClientFactory _httpClientFactory;
-        private readonly IServerApplicationHost _appHost;
 
-        public M3uParser(ILogger logger, IHttpClientFactory httpClientFactory, IServerApplicationHost appHost)
+        public M3uParser(ILogger logger, IHttpClientFactory httpClientFactory)
         {
             _logger = logger;
             _httpClientFactory = httpClientFactory;
-            _appHost = appHost;
         }
 
         public async Task<List<ChannelInfo>> Parse(TunerHostInfo info, string channelIdPrefix, CancellationToken cancellationToken)
@@ -59,8 +61,6 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
             return File.OpenRead(info.Url);
         }
 
-        private const string ExtInfPrefix = "#EXTINF:";
-
         private async Task<List<ChannelInfo>> GetChannelsAsync(TextReader reader, string channelIdPrefix, string tunerHostId)
         {
             var channels = new List<ChannelInfo>();

Emby.Server.Implementations/LiveTv/TunerHosts/SharedHttpStream.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -89,8 +91,6 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
 
             var taskCompletionSource = new TaskCompletionSource<bool>();
 
-            var now = DateTime.UtcNow;
-
             _ = StartStreaming(response, taskCompletionSource, LiveStreamCancellationTokenSource.Token);
 
             // OpenedMediaSource.Protocol = MediaProtocol.File;
@@ -118,7 +118,7 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
             if (!taskCompletionSource.Task.Result)
             {
                 Logger.LogWarning("Zero bytes copied from stream {0} to {1} but no exception raised", GetType().Name, TempFilePath);
-                throw new EndOfStreamException(String.Format(CultureInfo.InvariantCulture, "Zero bytes copied from stream {0}", GetType().Name));
+                throw new EndOfStreamException(string.Format(CultureInfo.InvariantCulture, "Zero bytes copied from stream {0}", GetType().Name));
             }
         }
 

Emby.Server.Implementations/Localization/Core/ar.json

@@ -116,5 +116,7 @@
     "TaskCleanLogs": "حذف دليل السجل",
     "TaskCleanActivityLogDescription": "يحذف سجل الأنشطة الأقدم من الوقت الموضوع.",
     "TaskCleanActivityLog": "حذف سجل الأنشطة",
-    "Default": "الإعدادات الافتراضية"
+    "Default": "الإعدادات الافتراضية",
+    "Undefined": "غير معرف",
+    "Forced": "ملحقة"
 }

Emby.Server.Implementations/Localization/Core/en-US.json

@@ -117,5 +117,7 @@
     "TaskRefreshChannels": "Refresh Channels",
     "TaskRefreshChannelsDescription": "Refreshes internet channel information.",
     "TaskDownloadMissingSubtitles": "Download missing subtitles",
-    "TaskDownloadMissingSubtitlesDescription": "Searches the internet for missing subtitles based on metadata configuration."
+    "TaskDownloadMissingSubtitlesDescription": "Searches the internet for missing subtitles based on metadata configuration.",
+    "TaskOptimizeDatabase": "Optimize database",
+    "TaskOptimizeDatabaseDescription": "Compacts database and truncates free space. Running this task after scanning the library or doing other changes that imply database modifications might improve performance."
 }

Emby.Server.Implementations/Localization/Core/es.json

@@ -118,5 +118,7 @@
     "TaskCleanActivityLog": "Limpiar registro de actividad",
     "Undefined": "Indefinido",
     "Forced": "Forzado",
-    "Default": "Predeterminado"
+    "Default": "Predeterminado",
+    "TaskOptimizeDatabase": "Optimizar la base de datos",
+    "TaskOptimizeDatabaseDescription": "Compacta y libera el espacio libre en la base de datos. Ejecutar esta tarea tras escanear la biblioteca o hacer cambios que impliquen modificaciones en la base de datos puede mejorar el rendimiento."
 }

Emby.Server.Implementations/Localization/Core/nn.json

@@ -29,9 +29,9 @@
     "Collections": "Samlingar",
     "ChapterNameValue": "Kapittel {0}",
     "Channels": "Kanalar",
-    "CameraImageUploadedFrom": "Eit nytt kamera bilete har blitt lasta opp frå {0}",
+    "CameraImageUploadedFrom": "Eit nytt kamerabilete har blitt lasta opp frå {0}",
     "Books": "Bøker",
-    "AuthenticationSucceededWithUserName": "{0} Har logga inn",
+    "AuthenticationSucceededWithUserName": "{0} har logga inn",
     "Artists": "Artistar",
     "Application": "Program",
     "AppDeviceValues": "App: {0}, Eining: {1}",

Emby.Server.Implementations/Localization/LocalizationManager.cs

@@ -1,9 +1,10 @@
+#nullable disable
+
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Globalization;
 using System.IO;
-using System.Linq;
 using System.Reflection;
 using System.Text.Json;
 using System.Threading.Tasks;
@@ -167,12 +168,22 @@ namespace Emby.Server.Implementations.Localization
 
         /// <inheritdoc />
         public CultureDto FindLanguageInfo(string language)
-            => GetCultures()
-                .FirstOrDefault(i =>
-                    string.Equals(i.DisplayName, language, StringComparison.OrdinalIgnoreCase)
-                    || string.Equals(i.Name, language, StringComparison.OrdinalIgnoreCase)
-                    || i.ThreeLetterISOLanguageNames.Contains(language, StringComparer.OrdinalIgnoreCase)
-                    || string.Equals(i.TwoLetterISOLanguageName, language, StringComparison.OrdinalIgnoreCase));
+        {
+            // TODO language should ideally be a ReadOnlySpan but moq cannot mock ref structs
+            for (var i = 0; i < _cultures.Count; i++)
+            {
+                var culture = _cultures[i];
+                if (language.Equals(culture.DisplayName, StringComparison.OrdinalIgnoreCase)
+                    || language.Equals(culture.Name, StringComparison.OrdinalIgnoreCase)
+                    || culture.ThreeLetterISOLanguageNames.Contains(language, StringComparison.OrdinalIgnoreCase)
+                    || language.Equals(culture.TwoLetterISOLanguageName, StringComparison.OrdinalIgnoreCase))
+                {
+                    return culture;
+                }
+            }
+
+            return default;
+        }
 
         /// <inheritdoc />
         public IEnumerable<CountryInfo> GetCountries()
@@ -222,7 +233,7 @@ namespace Emby.Server.Implementations.Localization
                 throw new ArgumentNullException(nameof(rating));
             }
 
-            if (_unratedValues.Contains(rating, StringComparer.OrdinalIgnoreCase))
+            if (_unratedValues.Contains(rating.AsSpan(), StringComparison.OrdinalIgnoreCase))
             {
                 return null;
             }
@@ -250,11 +261,11 @@ namespace Emby.Server.Implementations.Localization
             var index = rating.IndexOf(':', StringComparison.Ordinal);
             if (index != -1)
             {
-                rating = rating.Substring(index).TrimStart(':').Trim();
+                var trimmedRating = rating.AsSpan(index).TrimStart(':').Trim();
 
-                if (!string.IsNullOrWhiteSpace(rating))
+                if (!trimmedRating.IsEmpty)
                 {
-                    return GetRatingLevel(rating);
+                    return GetRatingLevel(trimmedRating.ToString());
                 }
             }
 
@@ -316,7 +327,8 @@ namespace Emby.Server.Implementations.Localization
 
             return _dictionaries.GetOrAdd(
                 culture,
-                f => GetDictionary(Prefix, culture, DefaultCulture + ".json").GetAwaiter().GetResult());
+                (key, localizationManager) => localizationManager.GetDictionary(Prefix, key, DefaultCulture + ".json").GetAwaiter().GetResult(),
+                this);
         }
 
         private async Task<Dictionary<string, string>> GetDictionary(string prefix, string culture, string baseFilename)

Emby.Server.Implementations/MediaEncoder/EncodingManager.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Net/SocketFactory.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Net/UdpSocket.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;

Emby.Server.Implementations/Playlists/PlaylistManager.cs

@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;