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Diffstat (limited to 'lib/Plugins.Essentials.ServiceStack/src/ManagedPlugin.cs')
| -rw-r--r-- | lib/Plugins.Essentials.ServiceStack/src/ManagedPlugin.cs | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/lib/Plugins.Essentials.ServiceStack/src/ManagedPlugin.cs b/lib/Plugins.Essentials.ServiceStack/src/ManagedPlugin.cs new file mode 100644 index 0000000..596ea83 --- /dev/null +++ b/lib/Plugins.Essentials.ServiceStack/src/ManagedPlugin.cs @@ -0,0 +1,202 @@ +/* +* Copyright (c) 2023 Vaughn Nugent +* +* Library: VNLib +* Package: VNLib.Plugins.Essentials.ServiceStack +* File: ManagedPlugin.cs +* +* ManagedPlugin.cs is part of VNLib.Plugins.Essentials.ServiceStack which is part of the larger +* VNLib collection of libraries and utilities. +* +* VNLib.Plugins.Essentials.ServiceStack is free software: you can redistribute it and/or modify +* it under the terms of the GNU Affero General Public License as +* published by the Free Software Foundation, either version 2 of the +* License, or (at your option) any later version. +* +* VNLib.Plugins.Essentials.ServiceStack is distributed in the hope that it will be useful, +* but WITHOUT ANY WARRANTY; without even the implied warranty of +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +* GNU Affero General Public License for more details. +* +* You should have received a copy of the GNU Affero General Public License +* along with this program. If not, see https://www.gnu.org/licenses/. +*/ + +using System; +using System.IO; +using System.Linq; +using System.Threading; +using System.Reflection; +using System.Threading.Tasks; +using System.ComponentModel.Design; + +using VNLib.Utils; +using VNLib.Plugins.Runtime; +using VNLib.Plugins.Attributes; + +namespace VNLib.Plugins.Essentials.ServiceStack +{ + + internal sealed class ManagedPlugin : VnDisposeable, IPluginEventListener, IManagedPlugin + { + private readonly IPluginEventListener _serviceDomainListener; + private readonly RuntimePluginLoader _plugin; + + private UnloadableServiceContainer? _services; + + public ManagedPlugin(string pluginPath, PluginLoadConfiguration config, IPluginEventListener listener) + { + PluginPath = pluginPath; + + //configure the loader + _plugin = new(pluginPath, config.HostConfig, config.PluginErrorLog, config.HotReload, config.HotReload); + + //Register listener before loading occurs + _plugin.Controller.Register(this, this); + + //Store listener to raise events + _serviceDomainListener = listener; + } + + ///<inheritdoc/> + public string PluginPath { get; } + + ///<inheritdoc/> + public IUnloadableServiceProvider Services + { + get + { + Check(); + return _services!; + } + } + + ///<inheritdoc/> + public PluginController Controller + { + get + { + Check(); + return _plugin.Controller; + } + } + + internal string PluginFileName => Path.GetFileName(PluginPath); + + internal Task InitializePluginsAsync() + { + Check(); + return _plugin.InitializeController(); + } + + internal void LoadPlugins() + { + Check(); + _plugin.LoadPlugins(); + } + + /* + * Automatically called after the plugin has successfully loaded + * by event handlers below + */ + private void ConfigureServices() + { + //If the service container is defined, dispose + _services?.Dispose(); + + //Init new service container + _services = new(); + + //Get types from plugin + foreach (LivePlugin plugin in _plugin.Controller.Plugins) + { + /* + * Get the exposed configurator method if declared, + * it may not be defined. + */ + ServiceConfigurator? callback = plugin.PluginType.GetMethods() + .Where(static m => m.GetCustomAttribute<ServiceConfiguratorAttribute>() != null && !m.IsAbstract) + .Select(m => m.CreateDelegate<ServiceConfigurator>(plugin.Plugin)) + .FirstOrDefault(); + + //Invoke if defined to expose services + callback?.Invoke(_services); + } + } + + internal void ReloadPlugins() + { + Check(); + _plugin.ReloadPlugins(); + } + + internal void UnloadPlugins() + { + Check(); + + //unload plugins + _plugin.UnloadAll(); + + //Services will be cleaned up by the unload event + } + + void IPluginEventListener.OnPluginLoaded(PluginController controller, object? state) + { + //Initialize services after load, before passing event + ConfigureServices(); + + //Propagate event + _serviceDomainListener.OnPluginLoaded(controller, state); + } + + void IPluginEventListener.OnPluginUnloaded(PluginController controller, object? state) + { + //Cleanup services no longer in use. Plugin is still valid until this method returns + using (_services) + { + //Propagate event + _serviceDomainListener.OnPluginUnloaded(controller, state); + + //signal service cancel before disposing + _services?.SignalUnload(); + } + //Remove ref to services + _services = null; + } + + protected override void Free() + { + //Dispose services + _services?.Dispose(); + //Unregister the listener to cleanup resources + _plugin.Controller.Unregister(this); + //Dispose loader + _plugin.Dispose(); + } + + + private sealed class UnloadableServiceContainer : ServiceContainer, IUnloadableServiceProvider + { + private readonly CancellationTokenSource _cts; + + public UnloadableServiceContainer() : base() + { + _cts = new(); + } + + ///<inheritdoc/> + CancellationToken IUnloadableServiceProvider.UnloadToken => _cts.Token; + + /// <summary> + /// Signals to listensers that the service container will be unloading + /// </summary> + internal void SignalUnload() => _cts.Cancel(); + + protected override void Dispose(bool disposing) + { + base.Dispose(disposing); + _cts.Dispose(); + } + } + } +} |