Improved Command Queue

New: Limit concurrent tasks that require disk access
New: Prevent other tasks from running during application update

src/NzbDrone.Api/Commands/CommandModule.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using Sonarr.Http.Extensions;
@@ -10,7 +10,6 @@ using NzbDrone.Core.Messaging.Events;
 using NzbDrone.Core.ProgressMessaging;
 using NzbDrone.SignalR;
 using Sonarr.Http;
-using Sonarr.Http.Mapping;
 using Sonarr.Http.Validation;
 
 

src/NzbDrone.Common/Extensions/StringExtensions.cs

@@ -9,6 +9,8 @@ namespace NzbDrone.Common.Extensions
 {
     public static class StringExtensions
     {
+        private static readonly Regex CamelCaseRegex = new Regex("(?<!^)[A-Z]", RegexOptions.Compiled);
+
         public static string NullSafe(this string target)
         {
             return ((object)target).NullSafe().ToString();
@@ -133,5 +135,10 @@ namespace NzbDrone.Common.Extensions
 
             return Encoding.ASCII.GetString(new [] { byteResult });
         }
+
+        public static string SplitCamelCase(this string input)
+        {
+            return CamelCaseRegex.Replace(input, match => " " + match.Value);
+        }
     }
 }

src/NzbDrone.Core.Test/Messaging/Commands/CommandExecutorFixture.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Threading;
@@ -15,7 +15,7 @@ namespace NzbDrone.Core.Test.Messaging.Commands
     [TestFixture]
     public class CommandExecutorFixture : TestBase<CommandExecutor>
     {
-        private BlockingCollection<CommandModel> _commandQueue;
+        private CommandQueue _commandQueue;
         private Mock<IExecute<CommandA>> _executorA;
         private Mock<IExecute<CommandB>> _executorB;
         private bool _commandExecuted = false;
@@ -46,7 +46,7 @@ namespace NzbDrone.Core.Test.Messaging.Commands
 
         private void GivenCommandQueue()
         {
-            _commandQueue = new BlockingCollection<CommandModel>(new CommandQueue());
+            _commandQueue = new CommandQueue();
 
             Mocker.GetMock<IManageCommandQueue>()
                   .Setup(s => s.Queue(It.IsAny<CancellationToken>()))

src/NzbDrone.Core.Test/Messaging/Commands/CommandQueueManagerFixture.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using FluentAssertions;
 using Moq;
@@ -42,6 +43,10 @@ namespace NzbDrone.Core.Test.Messaging.Commands
         {
             var command = Subject.Push<CheckForFinishedDownloadCommand>(new CheckForFinishedDownloadCommand());
 
+            // Start the command to mimic CommandQueue's behaviour
+            command.StartedAt = DateTime.Now;
+            command.Status = CommandStatus.Started;
+
             Subject.Start(command);
             Subject.Complete(command, "All done");
             Subject.CleanCommands();

src/NzbDrone.Core/Download/CheckForFinishedDownloadCommand.cs

@@ -1,9 +1,9 @@
-using NzbDrone.Core.Messaging.Commands;
+using NzbDrone.Core.Messaging.Commands;
 
 namespace NzbDrone.Core.Download
 {
     public class CheckForFinishedDownloadCommand : Command
     {
-
+        public override bool RequiresDiskAccess => true;
     }
 }

src/NzbDrone.Core/MediaFiles/Commands/RenameFilesCommand.cs

@@ -9,6 +9,7 @@ namespace NzbDrone.Core.MediaFiles.Commands
         public List<int> Files { get; set; }
 
         public override bool SendUpdatesToClient => true;
+        public override bool RequiresDiskAccess => true;
 
         public RenameFilesCommand()
         {
@@ -20,4 +21,4 @@ namespace NzbDrone.Core.MediaFiles.Commands
             Files = files;
         }
     }
-}
+}

src/NzbDrone.Core/MediaFiles/Commands/RenameSeriesCommand.cs

@@ -8,6 +8,7 @@ namespace NzbDrone.Core.MediaFiles.Commands
         public List<int> SeriesIds { get; set; }
 
         public override bool SendUpdatesToClient => true;
+        public override bool RequiresDiskAccess => true;
 
         public RenameSeriesCommand()
         {

src/NzbDrone.Core/MediaFiles/EpisodeImport/Manual/ManualImportCommand.cs

@@ -1,4 +1,4 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using NzbDrone.Core.Messaging.Commands;
 
 namespace NzbDrone.Core.MediaFiles.EpisodeImport.Manual
@@ -8,6 +8,7 @@ namespace NzbDrone.Core.MediaFiles.EpisodeImport.Manual
         public List<ManualImportFile> Files { get; set; }
 
         public override bool SendUpdatesToClient => true;
+        public override bool RequiresDiskAccess => true;
 
         public ImportMode ImportMode { get; set; }
     }

src/NzbDrone.Core/Messaging/Commands/Command.cs

@@ -21,6 +21,8 @@ namespace NzbDrone.Core.Messaging.Commands
 
         public virtual bool UpdateScheduledTask => true;
         public virtual string CompletionMessage => "Completed";
+        public virtual bool RequiresDiskAccess => false;
+        public virtual bool IsExclusive => false;
 
         public string Name { get; private set; }
         public DateTime? LastExecutionTime { get; set; }

src/NzbDrone.Core/Messaging/Commands/CommandQueue.cs

@@ -1,27 +1,36 @@
-using System;
+using System;
 using System.Collections;
-using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading;
 
 namespace NzbDrone.Core.Messaging.Commands
 {
-    public class CommandQueue : IProducerConsumerCollection<CommandModel>
+    public class CommandQueue : IEnumerable
     {
-        private object Mutex = new object();
-
-        private List<CommandModel> _items;
+        private readonly object _mutex = new object();
+        private readonly List<CommandModel> _items;
 
         public CommandQueue()
         {
             _items = new List<CommandModel>();
         }
 
+        public int Count => _items.Count;
+
+        public void Add(CommandModel item)
+        {
+            lock (_mutex)
+            {
+                _items.Add(item);
+            }
+        }
+
         public IEnumerator<CommandModel> GetEnumerator()
         {
             List<CommandModel> copy = null;
 
-            lock (Mutex)
+            lock (_mutex)
             {
                 copy = new List<CommandModel>(_items);
             }
@@ -34,77 +43,140 @@ namespace NzbDrone.Core.Messaging.Commands
             return GetEnumerator();
         }
 
-        public void CopyTo(Array array, int index)
+        public List<CommandModel> All()
         {
-            lock (Mutex)
-            {
-                ((ICollection)_items).CopyTo(array, index);
-            }
-        }
+            List<CommandModel> rval = null;
 
-        public int Count => _items.Count;
-
-        public object SyncRoot => Mutex;
-
-        public bool IsSynchronized => true;
-
-        public void CopyTo(CommandModel[] array, int index)
-        {
-            lock (Mutex)
+            lock (_mutex)
             {
-                _items.CopyTo(array, index);
+                rval = _items;
             }
+
+            return rval;
         }
 
-        public bool TryAdd(CommandModel item)
+        public CommandModel Find(int id)
         {
-            Add(item);
-            return true;
+            return All().FirstOrDefault(q => q.Id == id);
         }
 
-        public bool TryTake(out CommandModel item)
+        public void RemoveMany(IEnumerable<CommandModel> commands)
         {
-            bool rval = true;
-            lock (Mutex)
+            lock (_mutex)
             {
-                if (_items.Count == 0)
+                foreach (var command in commands)
                 {
-                    item = default(CommandModel);
-                    rval = false;
+                    _items.Remove(command);
                 }
+            }
+        }
+        public bool RemoveIfQueued(int id)
+        {
+            var rval = false;
 
-                else
-                {
-                    item = _items.Where(c => c.Status == CommandStatus.Queued)
-                                 .OrderByDescending(c => c.Priority)
-                                 .ThenBy(c => c.QueuedAt)
-                                 .First();
+            lock (_mutex)
+            {
+                var command = _items.FirstOrDefault(q => q.Id == id);
 
-                    _items.Remove(item);
+                if (command?.Status == CommandStatus.Queued)
+                {
+                    _items.Remove(command);
+                    rval = true;
                 }
             }
 
             return rval;
         }
 
-        public CommandModel[] ToArray()
+        public List<CommandModel> QueuedOrStarted()
         {
-            CommandModel[] rval = null;
+            return All().Where(q => q.Status == CommandStatus.Queued || q.Status == CommandStatus.Started)
+                        .ToList();
+        }
+
+        public IEnumerable<CommandModel> GetConsumingEnumerable()
+        {
+            return GetConsumingEnumerable(CancellationToken.None);
+        }
 
-            lock (Mutex)
+        public IEnumerable<CommandModel> GetConsumingEnumerable(CancellationToken cancellationToken)
+        {
+            while (!cancellationToken.IsCancellationRequested)
             {
-                rval = _items.ToArray();
-            }
+                if (TryGet(out var command))
+                {
+                    yield return command;
+                }
 
-            return rval;
+                Thread.Sleep(10);
+            }
         }
 
-        public void Add(CommandModel item)
+        public bool TryGet(out CommandModel item)
         {
-            lock (Mutex)
+            var rval = true;
+            item = default(CommandModel);
+
+            lock (_mutex)
             {
-                _items.Add(item);
+                if (_items.Count == 0)
+                {
+                    rval = false;
+                }
+
+                else
+                {
+                    var startedCommands = _items.Where(c => c.Status == CommandStatus.Started)
+                                                .ToList();
+
+                    var localItem = _items.Where(c =>
+                                          {
+                                              // If an executing command requires disk access don't return a command that
+                                              // requires disk access. A lower priority or later queued task could be returned
+                                              // instead, but that will allow other tasks to execute whiule waiting for disk access.
+                                              if (startedCommands.Any(x => x.Body.RequiresDiskAccess))
+                                              {
+                                                  return c.Status == CommandStatus.Queued &&
+                                                         !c.Body.RequiresDiskAccess;
+                                              }
+
+                                              return c.Status == CommandStatus.Queued;
+                                          })
+                                          .OrderByDescending(c => c.Priority)
+                                          .ThenBy(c => c.QueuedAt)
+                                          .FirstOrDefault();
+
+                    // Nothing queued that meets the requirements
+                    if (localItem == null)
+                    {
+                        rval = false;
+                    }
+
+                    // If any executing command is exclusive don't want return another command until it completes.
+                    else if (startedCommands.Any(c => c.Body.IsExclusive))
+                    {
+                        rval = false;
+                    }
+
+                    // If the next command to execute is exclusive wait for executing commands to complete.
+                    // This will prevent other tasks from starting so the exclusive task executes in the order it should.
+                    else if (localItem.Body.IsExclusive && startedCommands.Any())
+                    {
+                        rval = false;
+                    }
+
+                    // A command ready to execute
+                    else
+                    {
+                        localItem.StartedAt = DateTime.UtcNow;
+                        localItem.Status = CommandStatus.Started;
+
+                        item = localItem;
+                    }
+                }
             }
+
+            return rval;
         }
     }
 }

src/NzbDrone.Core/Messaging/Commands/CommandQueueManager.cs

@@ -1,15 +1,15 @@
-using System;
-using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
 using NLog;
 using NzbDrone.Common;
-using NzbDrone.Common.Cache;
 using NzbDrone.Common.EnsureThat;
 using NzbDrone.Common.Serializer;
 using NzbDrone.Core.Lifecycle;
 using NzbDrone.Core.Messaging.Events;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net;
+using System.Threading;
+using NzbDrone.Core.Exceptions;
 
 namespace NzbDrone.Core.Messaging.Commands
 {
@@ -19,6 +19,7 @@ namespace NzbDrone.Core.Messaging.Commands
         CommandModel Push<TCommand>(TCommand command, CommandPriority priority = CommandPriority.Normal, CommandTrigger trigger = CommandTrigger.Unspecified) where TCommand : Command;
         CommandModel Push(string commandName, DateTime? lastExecutionTime, CommandPriority priority = CommandPriority.Normal, CommandTrigger trigger = CommandTrigger.Unspecified);
         IEnumerable<CommandModel> Queue(CancellationToken cancellationToken);
+        List<CommandModel> All();
         CommandModel Get(int id);
         List<CommandModel> GetStarted(); 
         void SetMessage(CommandModel command, string message);
@@ -26,6 +27,7 @@ namespace NzbDrone.Core.Messaging.Commands
         void Complete(CommandModel command, string message);
         void Fail(CommandModel command, string message, Exception e);
         void Requeue();
+        void Cancel(int id);
         void CleanCommands();
     }
 
@@ -35,20 +37,17 @@ namespace NzbDrone.Core.Messaging.Commands
         private readonly IServiceFactory _serviceFactory;
         private readonly Logger _logger;
 
-        private readonly ICached<CommandModel> _commandCache;
-        private readonly BlockingCollection<CommandModel> _commandQueue;
+        private readonly CommandQueue _commandQueue;
 
         public CommandQueueManager(ICommandRepository repo, 
                                    IServiceFactory serviceFactory,
-                                   ICacheManager cacheManager,
                                    Logger logger)
         {
             _repo = repo;
             _serviceFactory = serviceFactory;
             _logger = logger;
 
-            _commandCache = cacheManager.GetCache<CommandModel>(GetType());
-            _commandQueue = new BlockingCollection<CommandModel>(new CommandQueue());
+            _commandQueue = new CommandQueue();
         }
 
         public List<CommandModel> PushMany<TCommand>(List<TCommand> commands) where TCommand : Command
@@ -56,8 +55,7 @@ namespace NzbDrone.Core.Messaging.Commands
             _logger.Trace("Publishing {0} commands", commands.Count);
 
             var commandModels = new List<CommandModel>();
-            var existingCommands = _commandCache.Values.Where(q => q.Status == CommandStatus.Queued ||
-                                                              q.Status == CommandStatus.Started).ToList();
+            var existingCommands = _commandQueue.QueuedOrStarted();
 
             foreach (var command in commands)
             {
@@ -85,7 +83,6 @@ namespace NzbDrone.Core.Messaging.Commands
 
             foreach (var commandModel in commandModels)
             {
-                _commandCache.Set(commandModel.Id.ToString(), commandModel);
                 _commandQueue.Add(commandModel);
             }
 
@@ -122,7 +119,6 @@ namespace NzbDrone.Core.Messaging.Commands
             _logger.Trace("Inserting new command: {0}", commandModel.Name);
 
             _repo.Insert(commandModel);
-            _commandCache.Set(commandModel.Id.ToString(), commandModel);
             _commandQueue.Add(commandModel);
 
             return commandModel;
@@ -142,30 +138,39 @@ namespace NzbDrone.Core.Messaging.Commands
             return _commandQueue.GetConsumingEnumerable(cancellationToken);
         }
 
+        public List<CommandModel> All()
+        {
+            _logger.Trace("Getting all commands");
+            return _commandQueue.All();
+        }
+
         public CommandModel Get(int id)
         {
-            return _commandCache.Get(id.ToString(), () => FindCommand(_repo.Get(id)));
+            var command = _commandQueue.Find(id);
+
+            if (command == null)
+            {
+                command = _repo.Get(id);
+            }
+
+            return command;
         }
 
         public List<CommandModel> GetStarted()
         {
             _logger.Trace("Getting started commands");
-            return _commandCache.Values.Where(c => c.Status == CommandStatus.Started).ToList();
+            return _commandQueue.All().Where(c => c.Status == CommandStatus.Started).ToList();
         }
 
         public void SetMessage(CommandModel command, string message)
         {
             command.Message = message;
-            _commandCache.Set(command.Id.ToString(), command);
         }
 
         public void Start(CommandModel command)
         {
-            command.StartedAt = DateTime.UtcNow;
-            command.Status = CommandStatus.Started;
-
+            // Marks the command as started in the DB, the queue takes care of marking it as started on it's own
             _logger.Trace("Marking command as started: {0}", command.Name);
-            _commandCache.Set(command.Id.ToString(), command);         
             _repo.Start(command);
         }
 
@@ -189,16 +194,23 @@ namespace NzbDrone.Core.Messaging.Commands
             }
         }
 
+        public void Cancel(int id)
+        {
+            if (!_commandQueue.RemoveIfQueued(id))
+            {
+                throw new NzbDroneClientException(HttpStatusCode.Conflict, "Unable to cancel task");
+            }
+        }
+
         public void CleanCommands()
         {
             _logger.Trace("Cleaning up old commands");
             
-            var old = _commandCache.Values.Where(c => c.EndedAt < DateTime.UtcNow.AddMinutes(-5));
+            var commands = _commandQueue.All()
+                                        .Where(c => c.EndedAt < DateTime.UtcNow.AddMinutes(-5))
+                                        .ToList();
 
-            foreach (var command in old)
-            {
-                _commandCache.Remove(command.Id.ToString());
-            }
+            _commandQueue.RemoveMany(commands);
 
             _repo.Trim();
         }
@@ -213,18 +225,6 @@ namespace NzbDrone.Core.Messaging.Commands
             return Json.Deserialize("{}", commandType);
         }
 
-        private CommandModel FindCommand(CommandModel command)
-        {
-            var cachedCommand = _commandCache.Find(command.Id.ToString());
-
-            if (cachedCommand != null)
-            {
-                command.Message = cachedCommand.Message;
-            }
-
-            return command;
-        }
-
         private void Update(CommandModel command, CommandStatus status, string message)
         {
             SetMessage(command, message);
@@ -234,15 +234,14 @@ namespace NzbDrone.Core.Messaging.Commands
             command.Status = status;
 
             _logger.Trace("Updating command status");
-            _commandCache.Set(command.Id.ToString(), command);
             _repo.End(command);
         }
 
         private List<CommandModel> QueuedOrStarted(string name)
         {
-            return _commandCache.Values.Where(q => q.Name == name &&
-                                                   (q.Status == CommandStatus.Queued ||
-                                                    q.Status == CommandStatus.Started)).ToList();
+            return _commandQueue.QueuedOrStarted()
+                                .Where(q => q.Name == name)
+                                .ToList();
         }
 
         public void Handle(ApplicationStartedEvent message)

src/NzbDrone.Core/Messaging/Commands/CommandRepository.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Data.SQLite;
 using NzbDrone.Core.Datastore;

src/NzbDrone.Core/Tv/Commands/BulkMoveSeriesCommand.cs

@@ -10,6 +10,7 @@ namespace NzbDrone.Core.Tv.Commands
         public string DestinationRootFolder { get; set; }
 
         public override bool SendUpdatesToClient => true;
+        public override bool RequiresDiskAccess => true;
     }
 
     public class BulkMoveSeries : IEquatable<BulkMoveSeries>

src/NzbDrone.Core/Tv/Commands/MoveSeriesCommand.cs

@@ -9,5 +9,6 @@ namespace NzbDrone.Core.Tv.Commands
         public string DestinationPath { get; set; }
 
         public override bool SendUpdatesToClient => true;
+        public override bool RequiresDiskAccess => true;
     }
 }

src/NzbDrone.Core/Update/Commands/ApplicationUpdateCommand.cs

@@ -1,10 +1,11 @@
-using NzbDrone.Core.Messaging.Commands;
+using NzbDrone.Core.Messaging.Commands;
 
 namespace NzbDrone.Core.Update.Commands
 {
     public class ApplicationUpdateCommand : Command
     {
         public override bool SendUpdatesToClient => true;
+        public override bool IsExclusive => true;
 
         public override string CompletionMessage => null;
     }

src/Sonarr.Api.V3/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 Sonarr.Api.V3.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,
@@ -26,9 +29,13 @@ namespace Sonarr.Api.V3.Commands
             _commandQueueManager = commandQueueManager;
             _serviceFactory = serviceFactory;
 
+            _debouncer = new Debouncer(SendUpdates, TimeSpan.FromSeconds(0.1));
+            _pendingUpdates = new Dictionary<int, CommandResource>();
+
             GetResourceById = GetCommand;
             CreateResource = StartCommand;
             GetResourceAll = GetStartedCommands;
+            DeleteResource = CancelCommand;
 
             PostValidator.RuleFor(c => c.Name).NotBlank();
         }
@@ -56,15 +63,45 @@ namespace Sonarr.Api.V3.Commands
 
         private List<CommandResource> GetStartedCommands()
         {
-            return _commandQueueManager.GetStarted().ToResource();
+            return _commandQueueManager.All().ToResource();
+        }
+
+        private void CancelCommand(int id)
+        {
+            _commandQueueManager.Cancel(id);
         }
 
         public void Handle(CommandUpdatedEvent message)
         {
             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);
+
+                    if (pendingUpdate.Name == typeof(MessagingCleanupCommand).Name.Replace("Command", "") &&
+                        pendingUpdate.Status == CommandStatus.Completed)
+                    {
+                        BroadcastResourceChange(ModelAction.Sync);
+                    }
+                }
             }
         }
     }
-}
+}

src/Sonarr.Api.V3/Commands/CommandResource.cs

@@ -1,7 +1,8 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using Newtonsoft.Json;
+using NzbDrone.Common.Extensions;
 using NzbDrone.Core.Messaging.Commands;
 using Sonarr.Http.REST;
 
@@ -10,6 +11,7 @@ namespace Sonarr.Api.V3.Commands
     public class CommandResource : RestResource
     {
         public string Name { get; set; }
+        public string CommandName { get; set; }
         public string Message { get; set; }
         public Command Body { get; set; }
         public CommandPriority Priority { get; set; }
@@ -24,37 +26,6 @@ namespace Sonarr.Api.V3.Commands
         [JsonIgnore]
         public string CompletionMessage { get; set; }
 
-        //Legacy
-        public CommandStatus State
-        {
-            get
-            {
-                return Status;
-            }
-
-            set { }
-        }
-
-        public bool Manual
-        {
-            get
-            {
-                return Trigger == CommandTrigger.Manual;
-            }
-
-            set { }
-        }
-
-        public DateTime StartedOn
-        {
-            get
-            {
-                return Queued;
-            }
-
-            set { }
-        }
-
         public DateTime? StateChangeTime
         {
             get
@@ -106,6 +77,7 @@ namespace Sonarr.Api.V3.Commands
                 Id = model.Id,
 
                 Name = model.Name,
+                CommandName = model.Name.SplitCamelCase(),
                 Message = model.Message,
                 Body = model.Body,
                 Priority = model.Priority,

src/Sonarr.Api.V3/System/Tasks/TaskModule.cs

@@ -1,6 +1,7 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Linq;
 using System.Text.RegularExpressions;
+using NzbDrone.Common.Extensions;
 using NzbDrone.Core.Datastore.Events;
 using NzbDrone.Core.Jobs;
 using NzbDrone.Core.Messaging.Events;
@@ -13,8 +14,6 @@ namespace Sonarr.Api.V3.System.Tasks
     {
         private readonly ITaskManager _taskManager;
 
-        private static readonly Regex NameRegex = new Regex("(?<!^)[A-Z]", RegexOptions.Compiled);
-
         public TaskModule(ITaskManager taskManager, IBroadcastSignalRMessage broadcastSignalRMessage)
             : base(broadcastSignalRMessage, "system/task")
         {
@@ -51,7 +50,7 @@ namespace Sonarr.Api.V3.System.Tasks
             return new TaskResource
                    {
                        Id = scheduledTask.Id,
-                       Name = NameRegex.Replace(taskName, match => " " + match.Value),
+                       Name = taskName.SplitCamelCase(),
                        TaskName = taskName,
                        Interval = scheduledTask.Interval,
                        LastExecution = scheduledTask.LastExecution,