jellyfin/MediaBrowser.Common/Kernel/BaseKernel.cs
2013-02-22 22:49:00 -05:00

872 lines
29 KiB
C#

using MediaBrowser.Common.Events;
using MediaBrowser.Common.IO;
using MediaBrowser.Common.Net;
using MediaBrowser.Common.Plugins;
using MediaBrowser.Common.ScheduledTasks;
using MediaBrowser.Common.Serialization;
using MediaBrowser.Model.Configuration;
using MediaBrowser.Model.Logging;
using MediaBrowser.Model.System;
using System;
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.ComponentModel.Composition.Hosting;
using System.ComponentModel.Composition.Primitives;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Threading;
using System.Threading.Tasks;
namespace MediaBrowser.Common.Kernel
{
/// <summary>
/// Represents a shared base kernel for both the Ui and server apps
/// </summary>
/// <typeparam name="TConfigurationType">The type of the T configuration type.</typeparam>
/// <typeparam name="TApplicationPathsType">The type of the T application paths type.</typeparam>
public abstract class BaseKernel<TConfigurationType, TApplicationPathsType> : IDisposable, IKernel
where TConfigurationType : BaseApplicationConfiguration, new()
where TApplicationPathsType : BaseApplicationPaths, new()
{
/// <summary>
/// Occurs when [has pending restart changed].
/// </summary>
public event EventHandler HasPendingRestartChanged;
#region ConfigurationUpdated Event
/// <summary>
/// Occurs when [configuration updated].
/// </summary>
public event EventHandler<EventArgs> ConfigurationUpdated;
/// <summary>
/// Called when [configuration updated].
/// </summary>
internal void OnConfigurationUpdated()
{
EventHelper.QueueEventIfNotNull(ConfigurationUpdated, this, EventArgs.Empty, Logger);
// Notify connected clients
TcpManager.SendWebSocketMessage("ConfigurationUpdated", Configuration);
}
#endregion
#region LoggerLoaded Event
/// <summary>
/// Fires whenever the logger is loaded
/// </summary>
public event EventHandler LoggerLoaded;
/// <summary>
/// Called when [logger loaded].
/// </summary>
private void OnLoggerLoaded()
{
EventHelper.QueueEventIfNotNull(LoggerLoaded, this, EventArgs.Empty, Logger);
}
#endregion
#region ReloadBeginning Event
/// <summary>
/// Fires whenever the kernel begins reloading
/// </summary>
public event EventHandler<EventArgs> ReloadBeginning;
/// <summary>
/// Called when [reload beginning].
/// </summary>
private void OnReloadBeginning()
{
EventHelper.QueueEventIfNotNull(ReloadBeginning, this, EventArgs.Empty, Logger);
}
#endregion
#region ReloadCompleted Event
/// <summary>
/// Fires whenever the kernel completes reloading
/// </summary>
public event EventHandler<EventArgs> ReloadCompleted;
/// <summary>
/// Called when [reload completed].
/// </summary>
private void OnReloadCompleted()
{
EventHelper.QueueEventIfNotNull(ReloadCompleted, this, EventArgs.Empty, Logger);
}
#endregion
#region ApplicationUpdated Event
/// <summary>
/// Occurs when [application updated].
/// </summary>
public event EventHandler<GenericEventArgs<Version>> ApplicationUpdated;
/// <summary>
/// Called when [application updated].
/// </summary>
/// <param name="newVersion">The new version.</param>
public void OnApplicationUpdated(Version newVersion)
{
EventHelper.QueueEventIfNotNull(ApplicationUpdated, this, new GenericEventArgs<Version> { Argument = newVersion }, Logger);
NotifyPendingRestart();
}
#endregion
/// <summary>
/// The _configuration loaded
/// </summary>
private bool _configurationLoaded;
/// <summary>
/// The _configuration sync lock
/// </summary>
private object _configurationSyncLock = new object();
/// <summary>
/// The _configuration
/// </summary>
private TConfigurationType _configuration;
/// <summary>
/// Gets the system configuration
/// </summary>
/// <value>The configuration.</value>
public TConfigurationType Configuration
{
get
{
// Lazy load
LazyInitializer.EnsureInitialized(ref _configuration, ref _configurationLoaded, ref _configurationSyncLock, () => XmlSerializer.GetXmlConfiguration<TConfigurationType>(ApplicationPaths.SystemConfigurationFilePath, Logger));
return _configuration;
}
protected set
{
_configuration = value;
if (value == null)
{
_configurationLoaded = false;
}
}
}
/// <summary>
/// Gets a value indicating whether this instance is first run.
/// </summary>
/// <value><c>true</c> if this instance is first run; otherwise, <c>false</c>.</value>
public bool IsFirstRun { get; private set; }
/// <summary>
/// Gets or sets a value indicating whether this instance has changes that require the entire application to restart.
/// </summary>
/// <value><c>true</c> if this instance has pending application restart; otherwise, <c>false</c>.</value>
public bool HasPendingRestart { get; private set; }
/// <summary>
/// Gets the application paths.
/// </summary>
/// <value>The application paths.</value>
public TApplicationPathsType ApplicationPaths { get; private set; }
/// <summary>
/// The _failed assembly loads
/// </summary>
private readonly List<string> _failedPluginAssemblies = new List<string>();
/// <summary>
/// Gets the plugin assemblies that failed to load.
/// </summary>
/// <value>The failed assembly loads.</value>
public IEnumerable<string> FailedPluginAssemblies
{
get { return _failedPluginAssemblies; }
}
/// <summary>
/// Gets the list of currently loaded plugins
/// </summary>
/// <value>The plugins.</value>
[ImportMany(typeof(IPlugin))]
public IEnumerable<IPlugin> Plugins { get; protected set; }
/// <summary>
/// Gets the list of Scheduled Tasks
/// </summary>
/// <value>The scheduled tasks.</value>
[ImportMany(typeof(IScheduledTask))]
public IEnumerable<IScheduledTask> ScheduledTasks { get; private set; }
/// <summary>
/// Gets the web socket listeners.
/// </summary>
/// <value>The web socket listeners.</value>
public IEnumerable<IWebSocketListener> WebSocketListeners { get; private set; }
/// <summary>
/// Gets the MEF CompositionContainer
/// </summary>
/// <value>The composition container.</value>
private CompositionContainer CompositionContainer { get; set; }
/// <summary>
/// The _HTTP manager
/// </summary>
/// <value>The HTTP manager.</value>
public HttpManager HttpManager { get; private set; }
/// <summary>
/// Gets or sets the TCP manager.
/// </summary>
/// <value>The TCP manager.</value>
public TcpManager TcpManager { get; private set; }
/// <summary>
/// Gets the task manager.
/// </summary>
/// <value>The task manager.</value>
public TaskManager TaskManager { get; private set; }
/// <summary>
/// Gets the rest services.
/// </summary>
/// <value>The rest services.</value>
public IEnumerable<IRestfulService> RestServices { get; private set; }
/// <summary>
/// The disposable parts
/// </summary>
private readonly List<IDisposable> _disposableParts = new List<IDisposable>();
/// <summary>
/// The _protobuf serializer initialized
/// </summary>
private bool _protobufSerializerInitialized;
/// <summary>
/// The _protobuf serializer sync lock
/// </summary>
private object _protobufSerializerSyncLock = new object();
/// <summary>
/// Gets a dynamically compiled generated serializer that can serialize protocontracts without reflection
/// </summary>
private DynamicProtobufSerializer _protobufSerializer;
/// <summary>
/// Gets the protobuf serializer.
/// </summary>
/// <value>The protobuf serializer.</value>
public DynamicProtobufSerializer ProtobufSerializer
{
get
{
// Lazy load
LazyInitializer.EnsureInitialized(ref _protobufSerializer, ref _protobufSerializerInitialized, ref _protobufSerializerSyncLock, () => DynamicProtobufSerializer.Create(AllTypes));
return _protobufSerializer;
}
private set
{
_protobufSerializer = value;
if (value == null)
{
_protobufSerializerInitialized = false;
}
}
}
/// <summary>
/// Gets the UDP server port number.
/// This can't be configurable because then the user would have to configure their client to discover the server.
/// </summary>
/// <value>The UDP server port number.</value>
public abstract int UdpServerPortNumber { get; }
/// <summary>
/// Gets the name of the web application that can be used for url building.
/// All api urls will be of the form {protocol}://{host}:{port}/{appname}/...
/// </summary>
/// <value>The name of the web application.</value>
public string WebApplicationName
{
get { return "mediabrowser"; }
}
/// <summary>
/// Gets the HTTP server URL prefix.
/// </summary>
/// <value>The HTTP server URL prefix.</value>
public virtual string HttpServerUrlPrefix
{
get
{
return "http://+:" + Configuration.HttpServerPortNumber + "/" + WebApplicationName + "/";
}
}
/// <summary>
/// Gets the kernel context. Subclasses will have to override.
/// </summary>
/// <value>The kernel context.</value>
public abstract KernelContext KernelContext { get; }
/// <summary>
/// Gets the log file path.
/// </summary>
/// <value>The log file path.</value>
public string LogFilePath
{
get { return ApplicationHost.LogFilePath; }
}
/// <summary>
/// Gets the logger.
/// </summary>
/// <value>The logger.</value>
protected ILogger Logger { get; private set; }
/// <summary>
/// Gets or sets the application host.
/// </summary>
/// <value>The application host.</value>
protected IApplicationHost ApplicationHost { get; private set; }
/// <summary>
/// Gets the assemblies.
/// </summary>
/// <value>The assemblies.</value>
public Assembly[] Assemblies { get; private set; }
/// <summary>
/// Gets all types.
/// </summary>
/// <value>All types.</value>
public Type[] AllTypes { get; private set; }
/// <summary>
/// Initializes a new instance of the <see cref="BaseKernel{TApplicationPathsType}" /> class.
/// </summary>
/// <param name="appHost">The app host.</param>
/// <param name="logger">The logger.</param>
/// <exception cref="System.ArgumentNullException">isoManager</exception>
protected BaseKernel(IApplicationHost appHost, ILogger logger)
{
if (appHost == null)
{
throw new ArgumentNullException("appHost");
}
if (logger == null)
{
throw new ArgumentNullException("logger");
}
ApplicationHost = appHost;
Logger = logger;
}
/// <summary>
/// Initializes the Kernel
/// </summary>
/// <returns>Task.</returns>
public async Task Init()
{
ApplicationPaths = new TApplicationPathsType();
IsFirstRun = !File.Exists(ApplicationPaths.SystemConfigurationFilePath);
// Performs initializations that can be reloaded at anytime
await Reload().ConfigureAwait(false);
}
/// <summary>
/// Performs initializations that can be reloaded at anytime
/// </summary>
/// <returns>Task.</returns>
public async Task Reload()
{
OnReloadBeginning();
await ReloadInternal().ConfigureAwait(false);
OnReloadCompleted();
Logger.Info("Kernel.Reload Complete");
}
/// <summary>
/// Performs initializations that can be reloaded at anytime
/// </summary>
/// <returns>Task.</returns>
protected virtual async Task ReloadInternal()
{
// Set these to null so that they can be lazy loaded again
Configuration = null;
ProtobufSerializer = null;
ReloadLogger();
Logger.Info("Version {0} initializing", ApplicationVersion);
DisposeHttpManager();
HttpManager = new HttpManager(this, Logger);
await OnConfigurationLoaded().ConfigureAwait(false);
DisposeTaskManager();
TaskManager = new TaskManager(this, Logger);
Logger.Info("Loading Plugins");
await ReloadComposableParts().ConfigureAwait(false);
DisposeTcpManager();
TcpManager = new TcpManager(ApplicationHost, this, Logger);
}
/// <summary>
/// Called when [configuration loaded].
/// </summary>
/// <returns>Task.</returns>
protected virtual Task OnConfigurationLoaded()
{
return Task.FromResult<object>(null);
}
/// <summary>
/// Disposes and reloads all loggers
/// </summary>
public void ReloadLogger()
{
ApplicationHost.ReloadLogger();
OnLoggerLoaded();
}
/// <summary>
/// Uses MEF to locate plugins
/// Subclasses can use this to locate types within plugins
/// </summary>
/// <returns>Task.</returns>
private async Task ReloadComposableParts()
{
_failedPluginAssemblies.Clear();
DisposeComposableParts();
Assemblies = GetComposablePartAssemblies().ToArray();
AllTypes = Assemblies.SelectMany(GetTypes).ToArray();
ComposeParts(AllTypes);
await OnComposablePartsLoaded().ConfigureAwait(false);
CompositionContainer.Catalog.Dispose();
}
/// <summary>
/// Composes the parts.
/// </summary>
/// <param name="allTypes">All types.</param>
private void ComposeParts(IEnumerable<Type> allTypes)
{
var concreteTypes = allTypes.Where(t => t.IsClass && !t.IsAbstract && !t.IsInterface && !t.IsGenericType).ToArray();
CompositionContainer = GetSafeCompositionContainer(concreteTypes.Select(i => new TypeCatalog(i)));
RegisterExportedValues(CompositionContainer);
CompositionContainer.ComposeParts(this);
FindParts(concreteTypes);
}
/// <summary>
/// Composes the parts with ioc container.
/// </summary>
/// <param name="allTypes">All types.</param>
protected virtual void FindParts(Type[] allTypes)
{
RestServices = GetExports<IRestfulService>(allTypes);
WebSocketListeners = GetExports<IWebSocketListener>(allTypes);
}
/// <summary>
/// Gets the exports.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="allTypes">All types.</param>
/// <returns>IEnumerable{``0}.</returns>
protected IEnumerable<T> GetExports<T>(Type[] allTypes)
{
var currentType = typeof(T);
Logger.Info("Composing instances of " + currentType.Name);
var parts = allTypes.Where(currentType.IsAssignableFrom).Select(Instantiate).Cast<T>().ToArray();
_disposableParts.AddRange(parts.OfType<IDisposable>());
return parts;
}
/// <summary>
/// Instantiates the specified type.
/// </summary>
/// <param name="type">The type.</param>
/// <returns>System.Object.</returns>
private object Instantiate(Type type)
{
return ApplicationHost.CreateInstance(type);
}
/// <summary>
/// Composes the exported values.
/// </summary>
/// <param name="container">The container.</param>
protected virtual void RegisterExportedValues(CompositionContainer container)
{
ApplicationHost.Register<IKernel>(this);
container.ComposeExportedValue("logger", Logger);
container.ComposeExportedValue("appHost", ApplicationHost);
container.ComposeExportedValue("isoManager", ApplicationHost.Resolve<IIsoManager>());
}
/// <summary>
/// Gets the composable part assemblies.
/// </summary>
/// <returns>IEnumerable{Assembly}.</returns>
protected virtual IEnumerable<Assembly> GetComposablePartAssemblies()
{
// Gets all plugin assemblies by first reading all bytes of the .dll and calling Assembly.Load against that
// This will prevent the .dll file from getting locked, and allow us to replace it when needed
var pluginAssemblies = Directory.EnumerateFiles(ApplicationPaths.PluginsPath, "*.dll", SearchOption.TopDirectoryOnly)
.Select(file =>
{
try
{
return Assembly.Load(File.ReadAllBytes((file)));
}
catch (Exception ex)
{
_failedPluginAssemblies.Add(file);
Logger.ErrorException("Error loading {0}", ex, file);
return null;
}
}).Where(a => a != null);
foreach (var pluginAssembly in pluginAssemblies)
{
yield return pluginAssembly;
}
var runningDirectory = Path.GetDirectoryName(Process.GetCurrentProcess().MainModule.FileName);
var corePluginDirectory = Path.Combine(runningDirectory, "CorePlugins");
// This will prevent the .dll file from getting locked, and allow us to replace it when needed
pluginAssemblies = Directory.EnumerateFiles(corePluginDirectory, "*.dll", SearchOption.TopDirectoryOnly)
.Select(file =>
{
try
{
return Assembly.Load(File.ReadAllBytes((file)));
}
catch (Exception ex)
{
_failedPluginAssemblies.Add(file);
Logger.ErrorException("Error loading {0}", ex, file);
return null;
}
}).Where(a => a != null);
foreach (var pluginAssembly in pluginAssemblies)
{
yield return pluginAssembly;
}
// Include composable parts in the Model assembly
yield return typeof(SystemInfo).Assembly;
// Include composable parts in the Common assembly
yield return Assembly.GetExecutingAssembly();
// Include composable parts in the subclass assembly
yield return GetType().Assembly;
}
/// <summary>
/// Plugins that live on both the server and UI are going to have references to assemblies from both sides.
/// But looks for Parts on one side, it will throw an exception when it seems Types from the other side that it doesn't have a reference to.
/// For example, a plugin provides a Resolver. When MEF runs in the UI, it will throw an exception when it sees the resolver because there won't be a reference to the base class.
/// This method will catch those exceptions while retining the list of Types that MEF is able to resolve.
/// </summary>
/// <param name="catalogs">The catalogs.</param>
/// <returns>CompositionContainer.</returns>
/// <exception cref="System.ArgumentNullException">catalogs</exception>
private static CompositionContainer GetSafeCompositionContainer(IEnumerable<ComposablePartCatalog> catalogs)
{
if (catalogs == null)
{
throw new ArgumentNullException("catalogs");
}
var newList = new List<ComposablePartCatalog>();
// Go through each Catalog
foreach (var catalog in catalogs)
{
try
{
// Try to have MEF find Parts
catalog.Parts.ToArray();
// If it succeeds we can use the entire catalog
newList.Add(catalog);
}
catch (ReflectionTypeLoadException ex)
{
// If it fails we can still get a list of the Types it was able to resolve and create TypeCatalogs
var typeCatalogs = ex.Types.Where(t => t != null).Select(t => new TypeCatalog(t));
newList.AddRange(typeCatalogs);
}
}
return new CompositionContainer(new AggregateCatalog(newList));
}
/// <summary>
/// Gets a list of types within an assembly
/// This will handle situations that would normally throw an exception - such as a type within the assembly that depends on some other non-existant reference
/// </summary>
/// <param name="assembly">The assembly.</param>
/// <returns>IEnumerable{Type}.</returns>
/// <exception cref="System.ArgumentNullException">assembly</exception>
private static IEnumerable<Type> GetTypes(Assembly assembly)
{
if (assembly == null)
{
throw new ArgumentNullException("assembly");
}
try
{
return assembly.GetTypes();
}
catch (ReflectionTypeLoadException ex)
{
// If it fails we can still get a list of the Types it was able to resolve
return ex.Types.Where(t => t != null);
}
}
/// <summary>
/// Fires after MEF finishes finding composable parts within plugin assemblies
/// </summary>
/// <returns>Task.</returns>
protected virtual Task OnComposablePartsLoaded()
{
return Task.Run(() =>
{
foreach (var task in ScheduledTasks)
{
task.Initialize(this, Logger);
}
// Start-up each plugin
Parallel.ForEach(Plugins, plugin =>
{
Logger.Info("Initializing {0} {1}", plugin.Name, plugin.Version);
try
{
plugin.Initialize(this, Logger);
Logger.Info("{0} {1} initialized.", plugin.Name, plugin.Version);
}
catch (Exception ex)
{
Logger.ErrorException("Error initializing {0}", ex, plugin.Name);
}
});
});
}
/// <summary>
/// Notifies that the kernel that a change has been made that requires a restart
/// </summary>
public void NotifyPendingRestart()
{
HasPendingRestart = true;
TcpManager.SendWebSocketMessage("HasPendingRestartChanged", GetSystemInfo());
EventHelper.QueueEventIfNotNull(HasPendingRestartChanged, this, EventArgs.Empty, Logger);
}
/// <summary>
/// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
/// </summary>
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
/// <summary>
/// Releases unmanaged and - optionally - managed resources.
/// </summary>
/// <param name="dispose"><c>true</c> to release both managed and unmanaged resources; <c>false</c> to release only unmanaged resources.</param>
protected virtual void Dispose(bool dispose)
{
if (dispose)
{
DisposeTcpManager();
DisposeTaskManager();
DisposeHttpManager();
DisposeComposableParts();
foreach (var part in _disposableParts)
{
part.Dispose();
}
_disposableParts.Clear();
}
}
/// <summary>
/// Disposes the TCP manager.
/// </summary>
private void DisposeTcpManager()
{
if (TcpManager != null)
{
TcpManager.Dispose();
TcpManager = null;
}
}
/// <summary>
/// Disposes the task manager.
/// </summary>
private void DisposeTaskManager()
{
if (TaskManager != null)
{
TaskManager.Dispose();
TaskManager = null;
}
}
/// <summary>
/// Disposes the HTTP manager.
/// </summary>
private void DisposeHttpManager()
{
if (HttpManager != null)
{
HttpManager.Dispose();
HttpManager = null;
}
}
/// <summary>
/// Disposes all objects gathered through MEF composable parts
/// </summary>
protected virtual void DisposeComposableParts()
{
if (CompositionContainer != null)
{
CompositionContainer.Dispose();
}
}
/// <summary>
/// Gets the current application version
/// </summary>
/// <value>The application version.</value>
public Version ApplicationVersion
{
get
{
return GetType().Assembly.GetName().Version;
}
}
/// <summary>
/// Performs the pending restart.
/// </summary>
/// <returns>Task.</returns>
public void PerformPendingRestart()
{
if (HasPendingRestart)
{
RestartApplication();
}
else
{
Logger.Info("PerformPendingRestart - not needed");
}
}
/// <summary>
/// Restarts the application.
/// </summary>
protected void RestartApplication()
{
Logger.Info("Restarting the application");
ApplicationHost.Restart();
}
/// <summary>
/// Gets the system status.
/// </summary>
/// <returns>SystemInfo.</returns>
public virtual SystemInfo GetSystemInfo()
{
return new SystemInfo
{
HasPendingRestart = HasPendingRestart,
Version = ApplicationVersion.ToString(),
IsNetworkDeployed = ApplicationHost.CanSelfUpdate,
WebSocketPortNumber = TcpManager.WebSocketPortNumber,
SupportsNativeWebSocket = TcpManager.SupportsNativeWebSocket,
FailedPluginAssemblies = FailedPluginAssemblies.ToArray()
};
}
/// <summary>
/// The _save lock
/// </summary>
private readonly object _configurationSaveLock = new object();
/// <summary>
/// Saves the current configuration
/// </summary>
public void SaveConfiguration()
{
lock (_configurationSaveLock)
{
XmlSerializer.SerializeToFile(Configuration, ApplicationPaths.SystemConfigurationFilePath);
}
OnConfigurationUpdated();
}
/// <summary>
/// Gets the application paths.
/// </summary>
/// <value>The application paths.</value>
BaseApplicationPaths IKernel.ApplicationPaths
{
get { return ApplicationPaths; }
}
/// <summary>
/// Gets the configuration.
/// </summary>
/// <value>The configuration.</value>
BaseApplicationConfiguration IKernel.Configuration
{
get { return Configuration; }
}
}
}