Sonarr pulls (#310)

* New: Speed up sqlite3 initialization by disabling unused features

Co-Authored-By: taloth <taloth@users.noreply.github.com>

* New: Debounce Command Notifications

Co-Authored-By: taloth <taloth@users.noreply.github.com>

* Changed: Refactored PendingRelease logic for performance

Co-Authored-By: taloth <taloth@users.noreply.github.com>

* Added: Indexes to speed up DecisionMaker performance.

Co-Authored-By: taloth <taloth@users.noreply.github.com>

* New: Cache EventAggregator Subscribers

Co-Authored-By: taloth <taloth@users.noreply.github.com>

* Fixed: Hide fallback pending releases if temporarily delayed

Co-Authored-By: taloth <taloth@users.noreply.github.com>

src/Lidarr.Api.V1/Commands/CommandModule.cs

@@ -1,7 +1,8 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using NzbDrone.Common;
+using NzbDrone.Common.TPL;
 using NzbDrone.Core.Datastore.Events;
 using NzbDrone.Core.Messaging.Commands;
 using NzbDrone.Core.Messaging.Events;
@@ -17,6 +18,8 @@ namespace Lidarr.Api.V1.Commands
     {
         private readonly IManageCommandQueue _commandQueueManager;
         private readonly IServiceFactory _serviceFactory;
+        private readonly Debouncer _debouncer;
+        private readonly Dictionary<int, CommandResource> _pendingUpdates;
 
         public CommandModule(IManageCommandQueue commandQueueManager,
                              IBroadcastSignalRMessage signalRBroadcaster,
@@ -31,6 +34,9 @@ namespace Lidarr.Api.V1.Commands
             GetResourceAll = GetStartedCommands;
 
             PostValidator.RuleFor(c => c.Name).NotBlank();
+
+            _debouncer = new Debouncer(SendUpdates, TimeSpan.FromSeconds(0.1));
+            _pendingUpdates = new Dictionary<int, CommandResource>();
         }
 
         private CommandResource GetCommand(int id)
@@ -63,7 +69,25 @@ namespace Lidarr.Api.V1.Commands
         {
             if (message.Command.Body.SendUpdatesToClient)
             {
-                BroadcastResourceChange(ModelAction.Updated, message.Command.ToResource());
+                lock (_pendingUpdates)
+                {
+                    _pendingUpdates[message.Command.Id] = message.Command.ToResource();
+                }
+                _debouncer.Execute();
+            }
+        }
+
+        private void SendUpdates()
+        {
+            lock (_pendingUpdates)
+            {
+                var pendingUpdates = _pendingUpdates.Values.ToArray();
+                _pendingUpdates.Clear();
+
+                foreach (var pendingUpdate in pendingUpdates)
+                {
+                    BroadcastResourceChange(ModelAction.Updated, pendingUpdate);
+                }
             }
         }
     }

src/NzbDrone.Common/Extensions/IEnumerableExtensions.cs

@@ -51,6 +51,34 @@ namespace NzbDrone.Common.Extensions
             }
         }
 
+        public static Dictionary<TKey, TItem> ToDictionaryIgnoreDuplicates<TItem, TKey>(this IEnumerable<TItem> src, Func<TItem, TKey> keySelector)
+        {
+            var result = new Dictionary<TKey, TItem>();
+            foreach (var item in src)
+            {
+                var key = keySelector(item);
+                if (!result.ContainsKey(key))
+                {
+                    result[key] = item;
+                }
+            }
+            return result;
+        }
+
+        public static Dictionary<TKey, TValue> ToDictionaryIgnoreDuplicates<TItem, TKey, TValue>(this IEnumerable<TItem> src, Func<TItem, TKey> keySelector, Func<TItem, TValue> valueSelector)
+        {
+            var result = new Dictionary<TKey, TValue>();
+            foreach (var item in src)
+            {
+                var key = keySelector(item);
+                if (!result.ContainsKey(key))
+                {
+                    result[key] = valueSelector(item);
+                }
+            }
+            return result;
+        }
+
         public static void AddIfNotNull<TSource>(this List<TSource> source, TSource item)
         {
             if (item == null)

src/NzbDrone.Core.Test/Download/DownloadApprovedReportsTests/DownloadApprovedFixture.cs

@@ -211,7 +211,7 @@ namespace NzbDrone.Core.Test.Download.DownloadApprovedReportsTests
             decisions.Add(new DownloadDecision(remoteAlbum, new Rejection("Failure!", RejectionType.Temporary)));
 
             Subject.ProcessDecisions(decisions);
-            Mocker.GetMock<IPendingReleaseService>().Verify(v => v.Add(It.IsAny<DownloadDecision>(), It.IsAny<PendingReleaseReason>()), Times.Never());
+            Mocker.GetMock<IPendingReleaseService>().Verify(v => v.AddMany(It.IsAny<List<Tuple<DownloadDecision, PendingReleaseReason>>>()), Times.Never());
         }
 
         [Test]
@@ -225,7 +225,7 @@ namespace NzbDrone.Core.Test.Download.DownloadApprovedReportsTests
             decisions.Add(new DownloadDecision(remoteAlbum, new Rejection("Failure!", RejectionType.Temporary)));
 
             Subject.ProcessDecisions(decisions);
-            Mocker.GetMock<IPendingReleaseService>().Verify(v => v.Add(It.IsAny<DownloadDecision>(), It.IsAny<PendingReleaseReason>()), Times.Exactly(2));
+            Mocker.GetMock<IPendingReleaseService>().Verify(v => v.AddMany(It.IsAny<List<Tuple<DownloadDecision, PendingReleaseReason>>>()), Times.Once());
         }
 
         [Test]

src/NzbDrone.Core/Datastore/DbFactory.cs

@@ -28,11 +28,21 @@ namespace NzbDrone.Core.Datastore
 
         static DbFactory()
         {
+            InitializeEnvironment();
+
             MapRepository.Instance.ReflectionStrategy = new SimpleReflectionStrategy();
             TableMapping.Map();
         }
 
-        public static void RegisterDatabase(IContainer container)
+        private static void InitializeEnvironment()
+        {
+            // Speed up sqlite3 initialization since we don't use the config file and can't rely on preloading.
+            Environment.SetEnvironmentVariable("No_Expand", "true");
+            Environment.SetEnvironmentVariable("No_SQLiteXmlConfigFile", "true");
+            Environment.SetEnvironmentVariable("No_PreLoadSQLite", "true");
+        }
+
+    public static void RegisterDatabase(IContainer container)
         {
             var mainDb = new MainDatabase(container.Resolve<IDbFactory>().Create());
 

src/NzbDrone.Core/Datastore/Migration/016_update_artist_history_indexes.cs

@@ -0,0 +1,24 @@
+using FluentMigrator;
+using NzbDrone.Core.Datastore.Migration.Framework;
+
+namespace NzbDrone.Core.Datastore.Migration
+{
+    [Migration(16)]
+    public class update_artist_history_indexes : NzbDroneMigrationBase
+    {
+        protected override void MainDbUpgrade()
+        {
+            Create.Index().OnTable("Albums").OnColumn("ArtistId");
+            Create.Index().OnTable("Albums").OnColumn("ArtistId").Ascending()
+                                            .OnColumn("ReleaseDate").Ascending();
+
+            Delete.Index().OnTable("History").OnColumn("AlbumId");
+            Create.Index().OnTable("History").OnColumn("AlbumId").Ascending()
+                                             .OnColumn("Date").Descending();
+
+            Delete.Index().OnTable("History").OnColumn("DownloadId");
+            Create.Index().OnTable("History").OnColumn("DownloadId").Ascending()
+                                             .OnColumn("Date").Descending();
+        }
+    }
+}

src/NzbDrone.Core/Download/Pending/PendingReleaseService.cs

@@ -15,6 +15,7 @@ using NzbDrone.Core.Music.Events;
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using Marr.Data;
 
 namespace NzbDrone.Core.Download.Pending
 {
@@ -69,66 +70,72 @@ namespace NzbDrone.Core.Download.Pending
 
         public void Add(DownloadDecision decision, PendingReleaseReason reason)
         {
-            var alreadyPending = _repository.AllByArtistId(decision.RemoteAlbum.Artist.Id);
+            AddMany(new List<Tuple<DownloadDecision, PendingReleaseReason>> { Tuple.Create(decision, reason) });
-
-            alreadyPending = IncludeRemoteAlbums(alreadyPending);
-
-            Add(alreadyPending, decision, reason);
         }
 
         public void AddMany(List<Tuple<DownloadDecision, PendingReleaseReason>> decisions)
         {
-            var alreadyPending = decisions.Select(v => v.Item1.RemoteAlbum.Artist.Id).Distinct().SelectMany(_repository.AllByArtistId).ToList();
+            foreach (var artistDecisions in decisions.GroupBy(v => v.Item1.RemoteAlbum.Artist.Id))
-
-            alreadyPending = IncludeRemoteAlbums(alreadyPending);
-
-            foreach (var pair in decisions)
             {
-                Add(alreadyPending, pair.Item1, pair.Item2);
+                var artist = artistDecisions.First().Item1.RemoteAlbum.Artist;
-            }
+                var alreadyPending = _repository.AllByArtistId(artist.Id);
-        }
 
-        private void Add(List<PendingRelease> alreadyPending, DownloadDecision decision, PendingReleaseReason reason)
+                alreadyPending = IncludeRemoteAlbums(alreadyPending, artistDecisions.ToDictionaryIgnoreDuplicates(v => v.Item1.RemoteAlbum.Release.Title, v => v.Item1.RemoteAlbum));
-        {
+                var alreadyPendingByAlbum = CreateAlbumLookup(alreadyPending);
-            var albumIds = decision.RemoteAlbum.Albums.Select(e => e.Id);
-
-            var existingReports = alreadyPending.Where(r => r.RemoteAlbum.Albums.Select(e => e.Id)
-                                                             .Intersect(albumIds)
-                                                             .Any());
 
-            var matchingReports = existingReports.Where(MatchingReleasePredicate(decision.RemoteAlbum.Release)).ToList();
+                foreach (var pair in artistDecisions)
-
-            if (matchingReports.Any())
-            {
-                var matchingReport = matchingReports.First();
-
-                if (matchingReport.Reason != reason)
                 {
-                    _logger.Debug("The release {0} is already pending with reason {1}, changing to {2}", decision.RemoteAlbum, matchingReport.Reason, reason);
+                    var decision = pair.Item1;
-                    matchingReport.Reason = reason;
+                    var reason = pair.Item2;
-                    _repository.Update(matchingReport);
-                }
 
-                else
+                    var albumIds = decision.RemoteAlbum.Albums.Select(e => e.Id);
-                {
-                    _logger.Debug("The release {0} is already pending with reason {1}, not adding again", decision.RemoteAlbum, reason); return;
-                }
 
-                if (matchingReports.Count() > 1)
+                    var existingReports = albumIds.SelectMany(v => alreadyPendingByAlbum[v] ?? Enumerable.Empty<PendingRelease>())
-                {
+                                                    .Distinct().ToList();
-                    _logger.Debug("The release {0} had {1} duplicate pending, removing duplicates.", decision.RemoteAlbum, matchingReports.Count() - 1);
+
+                    var matchingReports = existingReports.Where(MatchingReleasePredicate(decision.RemoteAlbum.Release)).ToList();
 
-                    foreach (var duplicate in matchingReports.Skip(1))
+                    if (matchingReports.Any())
                     {
-                        _repository.Delete(duplicate.Id);
+                        var matchingReport = matchingReports.First();
-                        alreadyPending.Remove(duplicate);
+
+                        if (matchingReport.Reason != reason)
+                        {
+                            _logger.Debug("The release {0} is already pending with reason {1}, changing to {2}", decision.RemoteAlbum, matchingReport.Reason, reason);
+                            matchingReport.Reason = reason;
+                            _repository.Update(matchingReport);
+                        }
+                        else
+                        {
+                            _logger.Debug("The release {0} is already pending with reason {1}, not adding again", decision.RemoteAlbum, reason);
+                        }
+
+                        if (matchingReports.Count() > 1)
+                        {
+                            _logger.Debug("The release {0} had {1} duplicate pending, removing duplicates.", decision.RemoteAlbum, matchingReports.Count() - 1);
+
+                            foreach (var duplicate in matchingReports.Skip(1))
+                            {
+                                _repository.Delete(duplicate.Id);
+                                alreadyPending.Remove(duplicate);
+                                alreadyPendingByAlbum = CreateAlbumLookup(alreadyPending);
+                            }
+                        }
+
+                        continue;
                     }
-                }
 
-                return;
+                    _logger.Debug("Adding release {0} to pending releases with reason {1}", decision.RemoteAlbum, reason);
+                    Insert(decision, reason);
+                }
             }
+        }
 
-            _logger.Debug("Adding release {0} to pending releases with reason {1}", decision.RemoteAlbum, reason); Insert(decision, reason);
+        private ILookup<int, PendingRelease> CreateAlbumLookup(IEnumerable<PendingRelease> alreadyPending)
+        {
+            return alreadyPending.SelectMany(v => v.RemoteAlbum.Albums
+                    .Select(d => new { Album = d, PendingRelease = v }))
+                .ToLookup(v => v.Album.Id, v => v.PendingRelease);
         }
 
         public List<ReleaseInfo> GetPending()
@@ -185,20 +192,20 @@ namespace NzbDrone.Core.Download.Pending
                     }
 
                     var queue = new Queue.Queue
-                                {
+                    {
-                                    Id = GetQueueId(pendingRelease, album),
+                        Id = GetQueueId(pendingRelease, album),
-                                    Artist = pendingRelease.RemoteAlbum.Artist,
+                        Artist = pendingRelease.RemoteAlbum.Artist,
-                                    Album = album,
+                        Album = album,
-                                    Quality = pendingRelease.RemoteAlbum.ParsedAlbumInfo.Quality,
+                        Quality = pendingRelease.RemoteAlbum.ParsedAlbumInfo.Quality,
-                                    Title = pendingRelease.Title,
+                        Title = pendingRelease.Title,
-                                    Size = pendingRelease.RemoteAlbum.Release.Size,
+                        Size = pendingRelease.RemoteAlbum.Release.Size,
-                                    Sizeleft = pendingRelease.RemoteAlbum.Release.Size,
+                        Sizeleft = pendingRelease.RemoteAlbum.Release.Size,
-                                    RemoteAlbum = pendingRelease.RemoteAlbum,
+                        RemoteAlbum = pendingRelease.RemoteAlbum,
-                                    Timeleft = timeleft,
+                        Timeleft = timeleft,
-                                    EstimatedCompletionTime = ect,
+                        EstimatedCompletionTime = ect,
-                                    Status = pendingRelease.Reason.ToString(),
+                        Status = pendingRelease.Reason.ToString(),
-                                    Protocol = pendingRelease.RemoteAlbum.Release.DownloadProtocol,
+                        Protocol = pendingRelease.RemoteAlbum.Release.DownloadProtocol,
-                                    Indexer = pendingRelease.RemoteAlbum.Release.Indexer
+                        Indexer = pendingRelease.RemoteAlbum.Release.Indexer
                     };
 
                     queued.Add(queue);
@@ -254,11 +261,27 @@ namespace NzbDrone.Core.Download.Pending
             return IncludeRemoteAlbums(_repository.AllByArtistId(artistId).ToList());
         }
 
-        private List<PendingRelease> IncludeRemoteAlbums(List<PendingRelease> releases)
+        private List<PendingRelease> IncludeRemoteAlbums(List<PendingRelease> releases, Dictionary<string, RemoteAlbum> knownRemoteAlbums = null)
         {
             var result = new List<PendingRelease>();
-            var artistMap = _artistService.GetArtists(releases.Select(v => v.ArtistId).Distinct())
+
-                                          .ToDictionary(v => v.Id);
+            var artistMap = new Dictionary<int, Artist>();
+
+            if (knownRemoteAlbums != null)
+            {
+                foreach (var artist in knownRemoteAlbums.Values.Select(v => v.Artist))
+                {
+                    if (!artistMap.ContainsKey(artist.Id))
+                    {
+                        artistMap[artist.Id] = artist;
+                    }
+                }
+            }
+
+            foreach (var artist in _artistService.GetArtists(releases.Select(v => v.ArtistId).Distinct().Where(v => !artistMap.ContainsKey(v))))
+            {
+                artistMap[artist.Id] = artist;
+            }
 
             foreach (var release in releases)
             {
@@ -267,7 +290,17 @@ namespace NzbDrone.Core.Download.Pending
                 // Just in case the artist was removed, but wasn't cleaned up yet (housekeeper will clean it up)
                 if (artist == null) return null;
 
-                var albums = _parsingService.GetAlbums(release.ParsedAlbumInfo, artist);
+                List<Album> albums;
+
+                RemoteAlbum knownRemoteAlbum;
+                if (knownRemoteAlbums != null && knownRemoteAlbums.TryGetValue(release.Release.Title, out knownRemoteAlbum))
+                {
+                    albums = knownRemoteAlbum.Albums;
+                }
+                else
+                {
+                    albums = _parsingService.GetAlbums(release.ParsedAlbumInfo, artist);
+                }
 
                 release.RemoteAlbum = new RemoteAlbum
                 {

src/NzbDrone.Core/Download/ProcessDownloadDecisions.cs

@@ -40,9 +40,11 @@ namespace NzbDrone.Core.Download
             var prioritizedDecisions = _prioritizeDownloadDecision.PrioritizeDecisions(qualifiedReports);
             var grabbed = new List<DownloadDecision>();
             var pending = new List<DownloadDecision>();
-            var failed = new List<DownloadDecision>();
+            //var failed = new List<DownloadDecision>();
             var rejected = decisions.Where(d => d.Rejected).ToList();
 
+            var pendingAddQueue = new List<Tuple<DownloadDecision, PendingReleaseReason>>();
+
             var usenetFailed = false;
             var torrentFailed = false;
 
@@ -59,15 +61,14 @@ namespace NzbDrone.Core.Download
 
                 if (report.TemporarilyRejected)
                 {
-                    _pendingReleaseService.Add(report, PendingReleaseReason.Delay);
+                    PreparePending(pendingAddQueue, grabbed, pending, report, PendingReleaseReason.Delay);
-                    pending.Add(report);
                     continue;
                 }
 
                 if (downloadProtocol == DownloadProtocol.Usenet && usenetFailed ||
                     downloadProtocol == DownloadProtocol.Torrent && torrentFailed)
                 {
-                    failed.Add(report);
+                    PreparePending(pendingAddQueue, grabbed, pending, report, PendingReleaseReason.DownloadClientUnavailable);
                     continue;
                 }
 
@@ -86,7 +87,7 @@ namespace NzbDrone.Core.Download
                     if (ex is DownloadClientUnavailableException || ex is DownloadClientAuthenticationException)
                     {
                         _logger.Debug(ex, "Failed to send release to download client, storing until later. " + remoteAlbum);
-                        failed.Add(report);
+                        PreparePending(pendingAddQueue, grabbed, pending, report, PendingReleaseReason.DownloadClientUnavailable);
 
                         if (downloadProtocol == DownloadProtocol.Usenet)
                         {
@@ -104,7 +105,10 @@ namespace NzbDrone.Core.Download
                 }
             }
 
-            pending.AddRange(ProcessFailedGrabs(grabbed, failed));
+            if (pendingAddQueue.Any())
+            {
+                _pendingReleaseService.AddMany(pendingAddQueue);
+            }
 
             return new ProcessedDecisions(grabbed, pending, rejected);
         }
@@ -126,45 +130,22 @@ namespace NzbDrone.Core.Download
                             .Any();
         }
 
-        private List<DownloadDecision> ProcessFailedGrabs(List<DownloadDecision> grabbed, List<DownloadDecision> failed)
+        private void PreparePending(List<Tuple<DownloadDecision, PendingReleaseReason>> queue, List<DownloadDecision> grabbed, List<DownloadDecision> pending, DownloadDecision report, PendingReleaseReason reason)
         {
-            var pending = new List<DownloadDecision>();
+            // If a release was already grabbed with matching albums we should store it as a fallback
-            var stored = new List<DownloadDecision>();
+            // and filter it out the next time it is processed.
-
+            // If a higher quality release failed to add to the download client, but a lower quality release
-            var addQueue = new List<Tuple<DownloadDecision, PendingReleaseReason>>();
+            // was sent to another client we still list it normally so it apparent that it'll grab next time.
-
+            // Delayed is treated the same, but only the first is listed the subsequent items as stored as Fallback.
-            foreach (var report in failed)
+
-            {
+            if (IsAlbumProcessed(grabbed, report) ||
-                // If a release was already grabbed with matching albums we should store it as a fallback
+                IsAlbumProcessed(pending, report))
-                // and filter it out the next time it is processed incase a higher quality release failed to
-                // add to the download client, but a lower quality release was sent to another client
-                // If the release wasn't grabbed already, but was already stored, store it as a fallback,
-                // otherwise store it as DownloadClientUnavailable.
-
-                if (IsAlbumProcessed(grabbed, report))
-                {
-                    addQueue.Add(Tuple.Create(report, PendingReleaseReason.Fallback));
-                    pending.Add(report);
-                }
-                else if (IsAlbumProcessed(stored, report))
-                {
-                    addQueue.Add(Tuple.Create(report, PendingReleaseReason.Fallback));
-                    pending.Add(report);
-                }
-                else
-                {
-                    addQueue.Add(Tuple.Create(report, PendingReleaseReason.DownloadClientUnavailable));
-                    pending.Add(report);
-                    stored.Add(report);
-                }
-            }
-
-            if (addQueue.Any())
             {
-                _pendingReleaseService.AddMany(addQueue);
+                reason = PendingReleaseReason.Fallback;
             }
 
-            return pending;
+            queue.Add(Tuple.Create(report, reason));
+            pending.Add(report);
         }
     }
 }

src/NzbDrone.Core/Messaging/Events/EventAggregator.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using NLog;
@@ -15,11 +16,38 @@ namespace NzbDrone.Core.Messaging.Events
         private readonly IServiceFactory _serviceFactory;
         private readonly TaskFactory _taskFactory;
 
+        private readonly Dictionary<string, object> _eventSubscribers;
+
+        private class EventSubscribers<TEvent> where TEvent : class, IEvent
+        {
+            private IServiceFactory _serviceFactory;
+
+            public IHandle<TEvent>[] _syncHandlers;
+            public IHandleAsync<TEvent>[] _asyncHandlers;
+            public IHandleAsync<IEvent>[] _globalHandlers;
+
+            public EventSubscribers(IServiceFactory serviceFactory)
+            {
+                _serviceFactory = serviceFactory;
+
+                _syncHandlers = serviceFactory.BuildAll<IHandle<TEvent>>()
+                                              .OrderBy(GetEventHandleOrder)
+                                              .ToArray();
+
+                _globalHandlers = serviceFactory.BuildAll<IHandleAsync<IEvent>>()
+                                              .ToArray();
+
+                _asyncHandlers = serviceFactory.BuildAll<IHandleAsync<TEvent>>()
+                                               .ToArray();
+            }
+        }
+
         public EventAggregator(Logger logger, IServiceFactory serviceFactory)
         {
             _logger = logger;
             _serviceFactory = serviceFactory;
             _taskFactory = new TaskFactory();
+            _eventSubscribers = new Dictionary<string, object>();
         }
 
         public void PublishEvent<TEvent>(TEvent @event) where TEvent : class, IEvent
@@ -47,11 +75,21 @@ namespace NzbDrone.Core.Messaging.Events
 
             _logger.Trace("Publishing {0}", eventName);
 
+            EventSubscribers<TEvent> subscribers;
+            lock (_eventSubscribers)
+            {
+                object target;
+                if (!_eventSubscribers.TryGetValue(eventName, out target))
+                {
+                    _eventSubscribers[eventName] = target = new EventSubscribers<TEvent>(_serviceFactory);
+                }
+
+                subscribers = target as EventSubscribers<TEvent>;
+            }
+
 
             //call synchronous handlers first.
-            var handlers = _serviceFactory.BuildAll<IHandle<TEvent>>()
+            var handlers = subscribers._syncHandlers;
-                .OrderBy(GetEventHandleOrder)
-                .ToList();
 
             foreach (var handler in handlers)
             {
@@ -67,7 +105,7 @@ namespace NzbDrone.Core.Messaging.Events
                 }
             }
 
-            foreach (var handler in _serviceFactory.BuildAll<IHandleAsync<IEvent>>())
+            foreach (var handler in subscribers._globalHandlers)
             {
                 var handlerLocal = handler;
 
@@ -78,7 +116,7 @@ namespace NzbDrone.Core.Messaging.Events
                 .LogExceptions();
             }
 
-            foreach (var handler in _serviceFactory.BuildAll<IHandleAsync<TEvent>>())
+            foreach (var handler in subscribers._asyncHandlers)
             {
                 var handlerLocal = handler;
 
@@ -102,7 +140,7 @@ namespace NzbDrone.Core.Messaging.Events
             return string.Format("{0}<{1}>", eventType.Name.Remove(eventType.Name.IndexOf('`')), eventType.GetGenericArguments()[0].Name);
         }
 
-        private int GetEventHandleOrder<TEvent>(IHandle<TEvent> eventHandler) where TEvent : class, IEvent
+        internal static int GetEventHandleOrder<TEvent>(IHandle<TEvent> eventHandler) where TEvent : class, IEvent
         {
             // TODO: Convert "Handle" to nameof(eventHandler.Handle) after .net 4.5
             var method = eventHandler.GetType().GetMethod("Handle", new Type[] { typeof(TEvent) });

src/NzbDrone.Core/NzbDrone.Core.csproj

@@ -186,6 +186,7 @@
     <Compile Include="Datastore\Migration\011_import_lists.cs" />
     <Compile Include="Datastore\Migration\012_add_release_status.cs" />
     <Compile Include="Datastore\Migration\015_remove_fanzub.cs" />
+    <Compile Include="Datastore\Migration\016_update_artist_history_indexes.cs" />
     <Compile Include="Datastore\Migration\Framework\MigrationContext.cs" />
     <Compile Include="Datastore\Migration\Framework\MigrationController.cs" />
     <Compile Include="Datastore\Migration\Framework\MigrationDbFactory.cs" />