jellyfin-server/MediaBrowser.Common/Kernel/BaseKernel.cs
2012-08-19 11:58:35 -04:00

233 lines
8.2 KiB
C#

using System;
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.ComponentModel.Composition.Hosting;
using System.Configuration;
using System.IO;
using System.Linq;
using System.Reflection;
using MediaBrowser.Common.Configuration;
using MediaBrowser.Common.Logging;
using MediaBrowser.Common.Net;
using MediaBrowser.Common.Plugins;
using MediaBrowser.Common.Serialization;
using MediaBrowser.Model.Progress;
using System.Threading.Tasks;
namespace MediaBrowser.Common.Kernel
{
/// <summary>
/// Represents a shared base kernel for both the UI and server apps
/// </summary>
public abstract class BaseKernel<TConfigurationType, TApplicationPathsType> : IDisposable
where TConfigurationType : BaseApplicationConfiguration, new()
where TApplicationPathsType : BaseApplicationPaths, new()
{
/// <summary>
/// Gets the current configuration
/// </summary>
public TConfigurationType Configuration { get; private set; }
public TApplicationPathsType ApplicationPaths { get; private set; }
/// <summary>
/// Gets the list of currently loaded plugins
/// </summary>
[ImportMany(typeof(BasePlugin))]
public IEnumerable<BasePlugin> Plugins { get; private set; }
/// <summary>
/// Both the UI and server will have a built-in HttpServer.
/// People will inevitably want remote control apps so it's needed in the UI too.
/// </summary>
public HttpServer HttpServer { get; private set; }
/// <summary>
/// Gets the kernel context. The UI kernel will have to override this.
/// </summary>
protected KernelContext KernelContext { get { return KernelContext.Server; } }
public BaseKernel()
{
ApplicationPaths = new TApplicationPathsType();
}
public virtual Task Init(IProgress<TaskProgress> progress)
{
return Task.Run(() =>
{
ReloadLogger();
progress.Report(new TaskProgress() { Description = "Loading configuration", PercentComplete = 0 });
ReloadConfiguration();
progress.Report(new TaskProgress() { Description = "Starting Http server", PercentComplete = 5 });
ReloadHttpServer();
progress.Report(new TaskProgress() { Description = "Loading Plugins", PercentComplete = 10 });
ReloadComposableParts();
});
}
/// <summary>
/// Gets or sets the path to the current log file
/// </summary>
public static string LogFilePath { get; set; }
private void ReloadLogger()
{
DisposeLogger();
DateTime now = DateTime.Now;
LogFilePath = Path.Combine(ApplicationPaths.LogDirectoryPath, Assembly.GetExecutingAssembly().GetType().Name + "-" + now.ToString("dMyyyy") + "-" + now.Ticks + ".log");
FileStream fs = new FileStream(LogFilePath, FileMode.Append, FileAccess.Write, FileShare.Read);
Logger.LoggerInstance = new StreamLogger(fs);
}
/// <summary>
/// Uses MEF to locate plugins
/// Subclasses can use this to locate types within plugins
/// </summary>
protected void ReloadComposableParts()
{
// 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
IEnumerable<Assembly> pluginAssemblies = Directory.GetFiles(ApplicationPaths.PluginsPath, "*.dll", SearchOption.AllDirectories).Select(f => Assembly.Load(File.ReadAllBytes((f))));
var catalog = new AggregateCatalog(pluginAssemblies.Select(a => new AssemblyCatalog(a)));
//catalog.Catalogs.Add(new AssemblyCatalog(Assembly.GetExecutingAssembly()));
//catalog.Catalogs.Add(new AssemblyCatalog(GetType().Assembly));
var container = new CompositionContainer(catalog);
container.ComposeParts(this);
OnComposablePartsLoaded();
catalog.Dispose();
container.Dispose();
}
/// <summary>
/// Fires after MEF finishes finding composable parts within plugin assemblies
/// </summary>
protected virtual void OnComposablePartsLoaded()
{
// This event handler will allow any plugin to reference another
AppDomain.CurrentDomain.AssemblyResolve -= new ResolveEventHandler(CurrentDomain_AssemblyResolve);
AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(CurrentDomain_AssemblyResolve);
StartPlugins();
}
/// <summary>
/// Initializes all plugins
/// </summary>
private void StartPlugins()
{
foreach (BasePlugin plugin in Plugins)
{
Assembly assembly = plugin.GetType().Assembly;
AssemblyName assemblyName = assembly.GetName();
plugin.Version = assemblyName.Version;
plugin.Path = Path.Combine(ApplicationPaths.PluginsPath, assemblyName.Name);
plugin.Context = KernelContext;
plugin.ReloadConfiguration();
if (plugin.Enabled)
{
plugin.Init();
}
}
}
/// <summary>
/// Reloads application configuration from the config file
/// </summary>
protected virtual void ReloadConfiguration()
{
//Configuration information for anything other than server-specific configuration will have to come via the API... -ebr
// Deserialize config
if (!File.Exists(ApplicationPaths.SystemConfigurationFilePath))
{
Configuration = new TConfigurationType();
}
else
{
Configuration = XmlSerializer.DeserializeFromFile<TConfigurationType>(ApplicationPaths.SystemConfigurationFilePath);
}
Logger.LoggerInstance.LogSeverity = Configuration.LogSeverity;
}
/// <summary>
/// Restarts the Http Server, or starts it if not currently running
/// </summary>
private void ReloadHttpServer()
{
DisposeHttpServer();
HttpServer = new HttpServer("http://+:" + Configuration.HttpServerPortNumber + "/mediabrowser/");
}
/// <summary>
/// This snippet will allow any plugin to reference another
/// </summary>
Assembly CurrentDomain_AssemblyResolve(object sender, ResolveEventArgs args)
{
AssemblyName assemblyName = new AssemblyName(args.Name);
// Look for the .dll recursively within the plugins directory
string dll = Directory.GetFiles(ApplicationPaths.PluginsPath, "*.dll", SearchOption.AllDirectories)
.FirstOrDefault(f => Path.GetFileNameWithoutExtension(f) == assemblyName.Name);
// If we found a matching assembly, load it now
if (!string.IsNullOrEmpty(dll))
{
return Assembly.Load(File.ReadAllBytes(dll));
}
return null;
}
/// <summary>
/// Disposes all resources currently in use.
/// </summary>
public virtual void Dispose()
{
DisposeHttpServer();
DisposeLogger();
}
/// <summary>
/// Disposes the current HttpServer
/// </summary>
private void DisposeHttpServer()
{
if (HttpServer != null)
{
HttpServer.Dispose();
}
}
/// <summary>
/// Disposes the current Logger instance
/// </summary>
private void DisposeLogger()
{
if (Logger.LoggerInstance != null)
{
Logger.LoggerInstance.Dispose();
}
}
}
}