From 4ef0142747c4a0dd0c4cb71d8e7359c03b3a2942 Mon Sep 17 00:00:00 2001
From: vnugent <public@vaughnnugent.com>
Date: Tue, 2 Jan 2024 02:33:05 -0500
Subject: breaking changes: plugin service pools & move plugin api away from
 web related

---
 .../src/SharedPluginServiceProvider.cs             | 115 +++++++++++++++++++++
 1 file changed, 115 insertions(+)
 create mode 100644 lib/Plugins.Runtime/src/SharedPluginServiceProvider.cs

(limited to 'lib/Plugins.Runtime/src/SharedPluginServiceProvider.cs')

diff --git a/lib/Plugins.Runtime/src/SharedPluginServiceProvider.cs b/lib/Plugins.Runtime/src/SharedPluginServiceProvider.cs
new file mode 100644
index 0000000..a64ede3
--- /dev/null
+++ b/lib/Plugins.Runtime/src/SharedPluginServiceProvider.cs
@@ -0,0 +1,115 @@
+/*
+* Copyright (c) 2024 Vaughn Nugent
+* 
+* Library: VNLib
+* Package: VNLib.Plugins.Runtime
+* File: SharedPluginServiceProvider.cs 
+*
+* SharedPluginServiceProvider.cs is part of VNLib.Plugins.Runtime which 
+* is part of the larger VNLib collection of libraries and utilities.
+*
+* VNLib.Plugins.Runtime is free software: you can redistribute it and/or modify 
+* it under the terms of the GNU 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.Runtime 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 
+* General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License 
+* along with VNLib.Plugins.Runtime. If not, see http://www.gnu.org/licenses/.
+*/
+
+using System;
+using System.ComponentModel.Design;
+
+using VNLib.Utils;
+using VNLib.Plugins.Runtime.Services;
+
+namespace VNLib.Plugins.Runtime
+{
+    /// <summary>
+    /// Represents a single shared pool for a collection of plugins to 
+    /// export services to.
+    /// </summary>
+    public sealed class SharedPluginServiceProvider : 
+        VnDisposeable, 
+        IServiceProvider,
+        IPluginEventListener
+    {
+        private readonly ServiceContainer _serviceContainer = new();
+        private readonly object _syncRoot = new();
+
+        ///<inheritdoc/>
+        public object? GetService(Type serviceType) => _serviceContainer.GetService(serviceType);
+
+        /// <summary>
+        ///  Gets the service object of the specified type.
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <returns>
+        /// A service object of type serviceType. -or- null if 
+        /// there is no service object of type serviceType.
+        /// </returns>
+        public T? GetService<T>() where T : class => GetService(typeof(T)) as T;
+
+        void IPluginEventListener.OnPluginLoaded(PluginController controller, object? state)
+        {
+            //Add services
+            AddOrRemoveServices(controller, true);
+        }
+
+        void IPluginEventListener.OnPluginUnloaded(PluginController controller, object? state)
+        {
+            //Remove services
+            AddOrRemoveServices(controller, false);
+        }
+
+        private void AddOrRemoveServices(PluginController controller, bool add)
+        {
+            /*
+             * Depending on when services are loaded/unloaded, this instances
+             * may be disposeed so avoid raising an exception for a condition
+             * that doenst matter. If disposed, we dont need to clean anything up
+             */
+            if (Disposed)
+            {
+                return;
+            }
+
+            //Get all exported services
+            PluginServiceExport[] exports = controller.GetExportedServices();
+
+            //We need to hold a lock to synchronize access to the service container
+            lock (_syncRoot)
+            {
+                //if add flag is set, add the serivces, otherwise remove them
+                if (add)
+                {
+                    Array.ForEach(exports, e => _serviceContainer.AddService(e.ServiceType, e.Service));
+                }
+                else
+                {
+                    Array.ForEach(exports, e => _serviceContainer.RemoveService(e.ServiceType));
+                }
+            }
+
+            //cleanup any disposable services when removing
+            if (!add)
+            {
+                foreach(PluginServiceExport export in exports)
+                {
+                    if(export.Service is IDisposable disposable)
+                    {
+                        disposable.Dispose();
+                    }
+                }
+            }
+        }
+
+        ///<inheritdoc/>
+        protected override void Free() => _serviceContainer.Dispose();
+    }
+}
-- 
cgit