Added ability for HealthChecks to run on specific events.

src/NzbDrone.Common/Reflection/ReflectionExtensions.cs

@@ -60,6 +60,11 @@ public static T GetAttribute<T>(this MemberInfo member, bool isRequired = true)
             return (T)attribute;
         }
 
+        public static T[] GetAttributes<T>(this MemberInfo member) where T : Attribute
+        {
+            return member.GetCustomAttributes(typeof(T), false).OfType<T>().ToArray();
+        }
+
         public static Type FindTypeByName(this Assembly assembly, string name)
         {
             return assembly.GetTypes().SingleOrDefault(c => c.Name.Equals(name, StringComparison.InvariantCultureIgnoreCase));
@@ -70,4 +75,4 @@ public static bool HasAttribute<TAttribute>(this Type type)
             return type.GetCustomAttributes(typeof(TAttribute), true).Any();
         }
     }
-}
+}

src/NzbDrone.Core/HealthCheck/CheckOnAttribute.cs

@@ -0,0 +1,16 @@
+using System;
+using NzbDrone.Common.Messaging;
+
+namespace NzbDrone.Core.HealthCheck
+{
+    [AttributeUsage(AttributeTargets.Class, AllowMultiple = true)]
+    public class CheckOnAttribute: Attribute
+    {
+        public Type EventType { get; set; }
+
+        public CheckOnAttribute(Type eventType)
+        {
+            EventType = eventType;
+        }
+    }
+}

src/NzbDrone.Core/HealthCheck/Checks/AppDataLocationCheck.cs

@@ -1,5 +1,6 @@
 using NzbDrone.Common.EnvironmentInfo;
 using NzbDrone.Common.Extensions;
+using NzbDrone.Core.Configuration.Events;
 
 namespace NzbDrone.Core.HealthCheck.Checks
 {
@@ -11,7 +12,7 @@ public AppDataLocationCheck(IAppFolderInfo appFolderInfo)
         {
             _appFolderInfo = appFolderInfo;
         }
-        
+
         public override HealthCheck Check()
         {
             if (_appFolderInfo.StartUpFolder.IsParentPath(_appFolderInfo.AppDataFolder) ||
@@ -22,7 +23,5 @@ public override HealthCheck Check()
 
             return new HealthCheck(GetType());
         }
-
-        public override bool CheckOnConfigChange => false;
     }
 }

src/NzbDrone.Core/HealthCheck/Checks/DownloadClientCheck.cs

@@ -2,9 +2,12 @@
 using System.Linq;
 using NLog;
 using NzbDrone.Core.Download;
+using NzbDrone.Core.ThingiProvider.Events;
 
 namespace NzbDrone.Core.HealthCheck.Checks
 {
+    [CheckOn(typeof(ProviderUpdatedEvent<IDownloadClient>))]
+    [CheckOn(typeof(ProviderDeletedEvent<IDownloadClient>))]
     public class DownloadClientCheck : HealthCheckBase
     {
         private readonly IProvideDownloadClient _downloadClientProvider;

src/NzbDrone.Core/HealthCheck/Checks/DownloadClientStatusCheck.cs

@@ -2,9 +2,13 @@
 using System.Linq;
 using NzbDrone.Common.Extensions;
 using NzbDrone.Core.Download;
+using NzbDrone.Core.ThingiProvider.Events;
 
 namespace NzbDrone.Core.HealthCheck.Checks
 {
+    [CheckOn(typeof(ProviderUpdatedEvent<IDownloadClient>))]
+    [CheckOn(typeof(ProviderDeletedEvent<IDownloadClient>))]
+    [CheckOn(typeof(ProviderStatusChangedEvent<IDownloadClient>))]
     public class DownloadClientStatusCheck : HealthCheckBase
     {
         private readonly IDownloadClientFactory _providerFactory;

src/NzbDrone.Core/HealthCheck/Checks/DroneFactoryCheck.cs

@@ -1,9 +1,11 @@
 using NzbDrone.Common.Disk;
 using NzbDrone.Common.Extensions;
 using NzbDrone.Core.Configuration;
+using NzbDrone.Core.Configuration.Events;
 
 namespace NzbDrone.Core.HealthCheck.Checks
 {
+    [CheckOn(typeof(ConfigSavedEvent))]
     public class DroneFactoryCheck : HealthCheckBase
     {
         private readonly IConfigService _configService;
@@ -28,7 +30,7 @@ public override HealthCheck Check()
             {
                 return new HealthCheck(GetType(), HealthCheckResult.Error, "Drone factory folder does not exist");
             }
-            
+
             if (!_diskProvider.FolderWritable(droneFactoryFolder))
             {
                 return new HealthCheck(GetType(), HealthCheckResult.Error, "Unable to write to drone factory folder");

src/NzbDrone.Core/HealthCheck/Checks/ImportMechanismCheck.cs

@@ -3,13 +3,18 @@
 using System.Linq;
 using NzbDrone.Common.Disk;
 using NzbDrone.Core.Configuration;
+using NzbDrone.Core.Configuration.Events;
 using NzbDrone.Core.Download;
 using NzbDrone.Core.Download.Clients;
 using NzbDrone.Core.Download.Clients.Nzbget;
 using NzbDrone.Core.Download.Clients.Sabnzbd;
+using NzbDrone.Core.ThingiProvider.Events;
 
 namespace NzbDrone.Core.HealthCheck.Checks
 {
+    [CheckOn(typeof(ProviderUpdatedEvent<IDownloadClient>))]
+    [CheckOn(typeof(ProviderDeletedEvent<IDownloadClient>))]
+    [CheckOn(typeof(ConfigSavedEvent))]
     public class ImportMechanismCheck : HealthCheckBase
     {
         private readonly IConfigService _configService;

src/NzbDrone.Core/HealthCheck/Checks/IndexerRssCheck.cs

@@ -1,9 +1,13 @@
 using System.Linq;
 using NzbDrone.Common.Extensions;
 using NzbDrone.Core.Indexers;
+using NzbDrone.Core.ThingiProvider.Events;
 
 namespace NzbDrone.Core.HealthCheck.Checks
 {
+    [CheckOn(typeof(ProviderUpdatedEvent<IIndexer>))]
+    [CheckOn(typeof(ProviderDeletedEvent<IIndexer>))]
+    [CheckOn(typeof(ProviderStatusChangedEvent<IIndexer>))]
     public class IndexerRssCheck : HealthCheckBase
     {
         private readonly IIndexerFactory _indexerFactory;

src/NzbDrone.Core/HealthCheck/Checks/IndexerSearchCheck.cs

@@ -1,9 +1,13 @@
 using System.Linq;
 using NzbDrone.Common.Extensions;
 using NzbDrone.Core.Indexers;
+using NzbDrone.Core.ThingiProvider.Events;
 
 namespace NzbDrone.Core.HealthCheck.Checks
 {
+    [CheckOn(typeof(ProviderUpdatedEvent<IIndexer>))]
+    [CheckOn(typeof(ProviderDeletedEvent<IIndexer>))]
+    [CheckOn(typeof(ProviderStatusChangedEvent<IIndexer>))]
     public class IndexerSearchCheck : HealthCheckBase
     {
         private readonly IIndexerFactory _indexerFactory;

src/NzbDrone.Core/HealthCheck/Checks/IndexerStatusCheck.cs

@@ -2,9 +2,13 @@
 using System.Linq;
 using NzbDrone.Common.Extensions;
 using NzbDrone.Core.Indexers;
+using NzbDrone.Core.ThingiProvider.Events;
 
 namespace NzbDrone.Core.HealthCheck.Checks
 {
+    [CheckOn(typeof(ProviderUpdatedEvent<IIndexer>))]
+    [CheckOn(typeof(ProviderDeletedEvent<IIndexer>))]
+    [CheckOn(typeof(ProviderStatusChangedEvent<IIndexer>))]
     public class IndexerStatusCheck : HealthCheckBase
     {
         private readonly IIndexerFactory _providerFactory;

src/NzbDrone.Core/HealthCheck/Checks/MediaInfoDllCheck.cs

@@ -20,7 +20,5 @@ public override HealthCheck Check()
 
             return new HealthCheck(GetType());
         }
-
-        public override bool CheckOnConfigChange => false;
     }
 }

src/NzbDrone.Core/HealthCheck/Checks/MonoVersionCheck.cs

@@ -47,8 +47,6 @@ public override HealthCheck Check()
             return new HealthCheck(GetType(), HealthCheckResult.Warning, "You are running an old and unsupported version of Mono. Please upgrade Mono for improved stability.");
         }
 
-        public override bool CheckOnConfigChange => false;
-
         public override bool CheckOnSchedule => false;
 
         private bool HasMonoBug18599()
@@ -80,4 +78,4 @@ private bool HasMonoBug18599()
             return false;
         }
     }
-}
+}

src/NzbDrone.Core/HealthCheck/Checks/ProxyCheck.cs

@@ -5,9 +5,11 @@
 using System.Linq;
 using System.Net;
 using NzbDrone.Common.Cloud;
+using NzbDrone.Core.Configuration.Events;
 
 namespace NzbDrone.Core.HealthCheck.Checks
 {
+    [CheckOn(typeof(ConfigSavedEvent))]
     public class ProxyCheck : HealthCheckBase
     {
         private readonly Logger _logger;
@@ -43,7 +45,7 @@ public override HealthCheck Check()
                 {
                     var response = _client.Execute(request);
 
-                    // We only care about 400 responses, other error codes can be ignored 
+                    // We only care about 400 responses, other error codes can be ignored
                     if (response.StatusCode == HttpStatusCode.BadRequest)
                     {
                         _logger.Error("Proxy Health Check failed: {0}", response.StatusCode);

src/NzbDrone.Core/HealthCheck/Checks/RootFolderCheck.cs

@@ -1,9 +1,12 @@
 using System.Linq;
 using NzbDrone.Common.Disk;
 using NzbDrone.Core.Tv;
+using NzbDrone.Core.Tv.Events;
 
 namespace NzbDrone.Core.HealthCheck.Checks
 {
+    [CheckOn(typeof(SeriesDeletedEvent))]
+    [CheckOn(typeof(SeriesMovedEvent))]
     public class RootFolderCheck : HealthCheckBase
     {
         private readonly ISeriesService _seriesService;
@@ -36,7 +39,5 @@ public override HealthCheck Check()
 
             return new HealthCheck(GetType());
         }
-
-        public override bool CheckOnConfigChange => false;
     }
 }

src/NzbDrone.Core/HealthCheck/Checks/UpdateCheck.cs

@@ -4,10 +4,12 @@
 using NzbDrone.Common.EnvironmentInfo;
 using NzbDrone.Common.Extensions;
 using NzbDrone.Core.Configuration;
+using NzbDrone.Core.Configuration.Events;
 using NzbDrone.Core.Update;
 
 namespace NzbDrone.Core.HealthCheck.Checks
 {
+    [CheckOn(typeof(ConfigFileSavedEvent))]
     public class UpdateCheck : HealthCheckBase
     {
         private readonly IDiskProvider _diskProvider;
@@ -66,7 +68,5 @@ public override HealthCheck Check()
 
             return new HealthCheck(GetType());
         }
-
-        public override bool CheckOnConfigChange => false;
     }
 }

src/NzbDrone.Core/HealthCheck/HealthCheckBase.cs

@@ -6,8 +6,6 @@ public abstract class HealthCheckBase : IProvideHealthCheck
 
         public virtual bool CheckOnStartup => true;
 
-        public virtual bool CheckOnConfigChange => true;
-
         public virtual bool CheckOnSchedule => true;
     }
 }

src/NzbDrone.Core/HealthCheck/HealthCheckService.cs

@@ -3,6 +3,9 @@
 using System.Linq;
 using NLog;
 using NzbDrone.Common.Cache;
+using NzbDrone.Common.Extensions;
+using NzbDrone.Common.Messaging;
+using NzbDrone.Common.Reflection;
 using NzbDrone.Core.Configuration.Events;
 using NzbDrone.Core.Download;
 using NzbDrone.Core.Indexers;
@@ -21,13 +24,12 @@ public interface IHealthCheckService
     public class HealthCheckService : IHealthCheckService,
                                       IExecute<CheckHealthCommand>,
                                       IHandleAsync<ApplicationStartedEvent>,
-                                      IHandleAsync<ConfigSavedEvent>,
+                                      IHandleAsync<IEvent>
-                                      IHandleAsync<ProviderUpdatedEvent<IIndexer>>,
-                                      IHandleAsync<ProviderDeletedEvent<IIndexer>>,
-                                      IHandleAsync<ProviderUpdatedEvent<IDownloadClient>>,
-                                      IHandleAsync<ProviderDeletedEvent<IDownloadClient>>
     {
-        private readonly IEnumerable<IProvideHealthCheck> _healthChecks;
+        private readonly IProvideHealthCheck[] _healthChecks;
+        private readonly IProvideHealthCheck[] _startupHealthChecks;
+        private readonly IProvideHealthCheck[] _scheduledHealthChecks;
+        private readonly Dictionary<Type, IProvideHealthCheck[]> _eventDrivenHealthChecks;
         private readonly IEventAggregator _eventAggregator;
         private readonly ICacheManager _cacheManager;
         private readonly Logger _logger;
@@ -39,12 +41,16 @@ public HealthCheckService(IEnumerable<IProvideHealthCheck> healthChecks,
                                   ICacheManager cacheManager,
                                   Logger logger)
         {
-            _healthChecks = healthChecks;
+            _healthChecks = healthChecks.ToArray();
             _eventAggregator = eventAggregator;
             _cacheManager = cacheManager;
             _logger = logger;
 
             _healthCheckResults = _cacheManager.GetCache<HealthCheck>(GetType());
+
+            _startupHealthChecks = _healthChecks.Where(v => v.CheckOnStartup).ToArray();
+            _scheduledHealthChecks = _healthChecks.Where(v => v.CheckOnSchedule).ToArray();
+            _eventDrivenHealthChecks = GetEventDrivenHealthChecks();
         }
 
         public List<HealthCheck> Results()
@@ -52,10 +58,17 @@ public List<HealthCheck> Results()
             return _healthCheckResults.Values.ToList();
         }
 
-        private void PerformHealthCheck(Func<IProvideHealthCheck, bool> predicate)
+        private Dictionary<Type, IProvideHealthCheck[]> GetEventDrivenHealthChecks()
         {
-            var results = _healthChecks.Where(predicate)
+            return _healthChecks
-                                       .Select(c => c.Check())
+                .SelectMany(h => h.GetType().GetAttributes<CheckOnAttribute>().Select(a => Tuple.Create(a.EventType, h)))
+                .GroupBy(t => t.Item1, t => t.Item2)
+                .ToDictionary(g => g.Key, g => g.ToArray());
+        }
+
+        private void PerformHealthCheck(IProvideHealthCheck[] healthChecks)
+        {
+            var results = healthChecks.Select(c => c.Check())
                                        .ToList();
 
             foreach (var result in results)
@@ -76,37 +89,37 @@ private void PerformHealthCheck(Func<IProvideHealthCheck, bool> predicate)
 
         public void Execute(CheckHealthCommand message)
         {
-            PerformHealthCheck(c => message.Trigger == CommandTrigger.Manual || c.CheckOnSchedule);
+            if (message.Trigger == CommandTrigger.Manual)
+            {
+                PerformHealthCheck(_healthChecks);
+            }
+            else
+            {
+                PerformHealthCheck(_scheduledHealthChecks);
+            }
         }
 
         public void HandleAsync(ApplicationStartedEvent message)
         {
-            PerformHealthCheck(c => c.CheckOnStartup);
+            PerformHealthCheck(_startupHealthChecks);
         }
 
-        public void HandleAsync(ConfigSavedEvent message)
+        public void HandleAsync(IEvent message)
         {
-            PerformHealthCheck(c => c.CheckOnConfigChange);
+            if (message is HealthCheckCompleteEvent)
-        }
+            {
+                return;
+            }
 
-        public void HandleAsync(ProviderUpdatedEvent<IIndexer> message)
+            IProvideHealthCheck[] checks;
-        {
+            if (!_eventDrivenHealthChecks.TryGetValue(message.GetType(), out checks))
-            PerformHealthCheck(c => c.CheckOnConfigChange);
+            {
-        }
+                return;
+            }
 
-        public void HandleAsync(ProviderDeletedEvent<IIndexer> message)
+            // TODO: Add debounce
-        {
-            PerformHealthCheck(c => c.CheckOnConfigChange);
-        }
 
-        public void HandleAsync(ProviderUpdatedEvent<IDownloadClient> message)
+            PerformHealthCheck(checks);
-        {
-            PerformHealthCheck(c => c.CheckOnConfigChange);
-        }
-
-        public void HandleAsync(ProviderDeletedEvent<IDownloadClient> message)
-        {
-            PerformHealthCheck(c => c.CheckOnConfigChange);
         }
     }
 }

src/NzbDrone.Core/HealthCheck/IProvideHealthCheck.cs

@@ -4,7 +4,6 @@ public interface IProvideHealthCheck
     {
         HealthCheck Check();
         bool CheckOnStartup { get; }
-        bool CheckOnConfigChange { get; }
         bool CheckOnSchedule { get; }
     }
 }

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

@@ -62,6 +62,17 @@ public void PublishEvent<TEvent>(TEvent @event) where TEvent : class, IEvent
                 }
             }
 
+            foreach (var handler in _serviceFactory.BuildAll<IHandleAsync<IEvent>>())
+            {
+                var handlerLocal = handler;
+
+                _taskFactory.StartNew(() =>
+                {
+                    handlerLocal.HandleAsync(@event);
+                }, TaskCreationOptions.PreferFairness)
+                .LogExceptions();
+            }
+
             foreach (var handler in _serviceFactory.BuildAll<IHandleAsync<TEvent>>())
             {
                 var handlerLocal = handler;

src/NzbDrone.Core/NzbDrone.Core.csproj

@@ -577,6 +577,7 @@
     <Compile Include="HealthCheck\HealthCheckBase.cs" />
     <Compile Include="HealthCheck\HealthCheckCompleteEvent.cs" />
     <Compile Include="HealthCheck\HealthCheckService.cs" />
+    <Compile Include="HealthCheck\CheckOnAttribute.cs" />
     <Compile Include="HealthCheck\IProvideHealthCheck.cs" />
     <Compile Include="History\History.cs" />
     <Compile Include="History\HistoryRepository.cs" />