Managed assembly loading overhaul

6 files changed, 80 insertions, 67 deletions

diff --git a/lib/Plugins.Essentials.ServiceStack/src/HttpServiceStackBuilder.cs b/lib/Plugins.Essentials.ServiceStack/src/HttpServiceStackBuilder.cs
index 25b6d5f..ae3b736 100644
--- a/lib/Plugins.Essentials.ServiceStack/src/HttpServiceStackBuilder.cs
+++ b/lib/Plugins.Essentials.ServiceStack/src/HttpServiceStackBuilder.cs
@@ -23,7 +23,6 @@
 */
 
 using System;
-using System.Threading.Tasks;
 using System.Collections.Generic;
 
 using VNLib.Net.Http;
@@ -117,7 +116,7 @@ namespace VNLib.Plugins.Essentials.ServiceStack
         /// </summary>
         /// <returns>The newly constructed <see cref="HttpServiceStack"/> that may be used to manage your http services</returns>
         /// <exception cref="ArgumentNullException"></exception>
-        public async Task<HttpServiceStack> BuildAsync(PluginLoadConfiguration config, ILogProvider appLog)
+        public HttpServiceStack Build(IPluginLoadConfiguration config, ILogProvider appLog)
         {
             _ = _hostBuilder ?? throw new ArgumentNullException("WithDomainBuilder", "You have not configured a service domain configuration callback");
             _ = _getServers ?? throw new ArgumentNullException("WithHttp", "You have not configured a IHttpServer configuration callback");
@@ -132,7 +131,7 @@ namespace VNLib.Plugins.Essentials.ServiceStack
                 }
 
                 //Load plugins async
-                await sd.PluginManager.LoadPluginsAsync(config, appLog);
+                sd.PluginManager.LoadPlugins(config, appLog);
 
                 LinkedList<IHttpServer> servers = new();
 
diff --git a/lib/Plugins.Essentials.ServiceStack/src/IPluginAssemblyLoaderFactory.cs b/lib/Plugins.Essentials.ServiceStack/src/IPluginAssemblyLoaderFactory.cs
new file mode 100644
index 0000000..4cb5741
--- /dev/null
+++ b/lib/Plugins.Essentials.ServiceStack/src/IPluginAssemblyLoaderFactory.cs
@@ -0,0 +1,43 @@
+/*
+* Copyright (c) 2023 Vaughn Nugent
+* 
+* Library: VNLib
+* Package: VNLib.Plugins.Essentials.ServiceStack
+* File: IPluginAssemblyLoaderFactory.cs 
+*
+* IPluginAssemblyLoaderFactory.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 VNLib.Plugins.Runtime;
+
+namespace VNLib.Plugins.Essentials.ServiceStack
+{
+    /// <summary>
+    /// Represents a provider that creates a unique <see cref="IPluginAssemblyLoader"/> for the the 
+    /// loaded assembly file.
+    /// </summary>
+    public interface IPluginAssemblyLoaderFactory
+    {
+        /// <summary>
+        /// Gets a new and unique <see cref="IPluginAssemblyLoader"/> instance for a given plugin assembly 
+        /// file path
+        /// </summary>
+        /// <param name="pluginFile">The file path to the requested plugin assembly file</param>
+        /// <returns>The new <see cref="IPluginAssemblyLoader"/> to recover the plugin assembly manifest</returns>
+        IPluginAssemblyLoader GetLoaderForPluginFile(string pluginFile);
+    }
+}
diff --git a/lib/Plugins.Essentials.ServiceStack/src/IPluginController.cs b/lib/Plugins.Essentials.ServiceStack/src/IPluginController.cs
index fb9c340..3394208 100644
--- a/lib/Plugins.Essentials.ServiceStack/src/IPluginController.cs
+++ b/lib/Plugins.Essentials.ServiceStack/src/IPluginController.cs
@@ -23,7 +23,6 @@
 */
 
 using System;
-using System.Threading.Tasks;
 using System.Collections.Generic;
 
 using VNLib.Utils.Logging;
@@ -45,10 +44,10 @@ namespace VNLib.Plugins.Essentials.ServiceStack
         /// Loads all plugins specified by the host config to the service manager,
         /// or attempts to load plugins by the default
         /// </summary>
-        /// <param name="config">The configuration instance to pass to plugins</param>
+        /// <param name="config">The plugin loading configuration</param>
         /// <param name="appLog">A log provider to write message and errors to</param>
         /// <returns>A task that resolves when all plugins are loaded</returns>
-        Task LoadPluginsAsync(PluginLoadConfiguration config, ILogProvider appLog);
+        void LoadPlugins(IPluginLoadConfiguration config, ILogProvider appLog);
 
         /// <summary>
         /// Sends a message to a plugin identified by it's name.
diff --git a/lib/Plugins.Essentials.ServiceStack/src/ManagedPlugin.cs b/lib/Plugins.Essentials.ServiceStack/src/ManagedPlugin.cs
index 3bf99cb..54f0090 100644
--- a/lib/Plugins.Essentials.ServiceStack/src/ManagedPlugin.cs
+++ b/lib/Plugins.Essentials.ServiceStack/src/ManagedPlugin.cs
@@ -27,17 +27,12 @@ using System.IO;
 using System.Linq;
 using System.Threading;
 using System.Reflection;
-using System.Runtime.Loader;
-using System.Threading.Tasks;
 using System.ComponentModel.Design;
 
-using McMaster.NETCore.Plugins;
-
 using VNLib.Utils;
 using VNLib.Plugins.Runtime;
 using VNLib.Plugins.Attributes;
 
-
 namespace VNLib.Plugins.Essentials.ServiceStack
 {
 
@@ -48,39 +43,21 @@ namespace VNLib.Plugins.Essentials.ServiceStack
 
         private UnloadableServiceContainer? _services;
 
-        public ManagedPlugin(string pluginPath, in PluginLoadConfiguration config, IPluginEventListener listener)
+        public ManagedPlugin(RuntimePluginLoader loader, IPluginEventListener listener)
         {
-            PluginPath = pluginPath;
-
-            //Get the plugin config for the assembly
-            PluginConfig pConfig = GetConfigForAssemblyPath(pluginPath, in config);
-
             //configure the loader
-            _plugin = new(pConfig, config.HostConfig, config.PluginErrorLog);
+            _plugin = loader;
 
-            //Register listener before loading occurs
+            //Register loading event listener before loading occurs
             _plugin.Controller.Register(this, this);
 
             //Store listener to raise events
             _serviceDomainListener = listener;
         }
 
-        private static PluginConfig GetConfigForAssemblyPath(string asmPath, in PluginLoadConfiguration loadConfig)
-        {
-            PluginConfig config = new(asmPath)
-            {
-                IsUnloadable = loadConfig.HotReload,
-                EnableHotReload = loadConfig.HotReload,
-                IsLazyLoaded = false,
-                PreferSharedTypes = true,
-                DefaultContext = AssemblyLoadContext.Default,
-                ReloadDelay = loadConfig.ReloadDelay
-            };            
-            return config;
-        }
 
         ///<inheritdoc/>
-        public string PluginPath { get; }
+        public string PluginPath => _plugin.Config.AssemblyFile;
 
         ///<inheritdoc/>
         public IUnloadableServiceProvider Services
@@ -104,10 +81,10 @@ namespace VNLib.Plugins.Essentials.ServiceStack
 
         internal string PluginFileName => Path.GetFileName(PluginPath);
 
-        internal Task InitializePluginsAsync()
+        internal void InitializePlugins()
         {
             Check();
-            return _plugin.InitializeController();
+            _plugin.InitializeController();
         }
 
         internal void LoadPlugins()
diff --git a/lib/Plugins.Essentials.ServiceStack/src/PluginLoadConfiguration.cs b/lib/Plugins.Essentials.ServiceStack/src/PluginLoadConfiguration.cs
index 894ae55..9ab9a82 100644
--- a/lib/Plugins.Essentials.ServiceStack/src/PluginLoadConfiguration.cs
+++ b/lib/Plugins.Essentials.ServiceStack/src/PluginLoadConfiguration.cs
@@ -3,9 +3,9 @@
 * 
 * Library: VNLib
 * Package: VNLib.Plugins.Essentials.ServiceStack
-* File: PluginLoadConfiguration.cs 
+* File: IPluginLoadConfiguration.cs 
 *
-* PluginLoadConfiguration.cs is part of VNLib.Plugins.Essentials.ServiceStack 
+* IPluginLoadConfiguration.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 
@@ -30,38 +30,33 @@ using VNLib.Plugins.Runtime;
 
 namespace VNLib.Plugins.Essentials.ServiceStack
 {
+
     /// <summary>
     /// Plugin loading configuration variables
     /// </summary>
-    public readonly record struct PluginLoadConfiguration
+    public interface IPluginLoadConfiguration
     {
         /// <summary>
         /// The directory containing the dynamic plugin assemblies to load
         /// </summary>
-        public readonly string PluginDir { get; init; }
-
-        /// <summary>
-        /// A value that indicates if the internal <see cref="PluginController"/>
-        /// allows for hot-reload/unloadable plugin assemblies.
-        /// </summary>
-        public readonly bool HotReload { get; init; }
+        string PluginDir { get; }
 
         /// <summary>
         /// The optional host configuration file to merge with plugin config 
         /// to pass to the loading plugin.
         /// </summary>
-        public readonly JsonElement? HostConfig { get; init; }
+        JsonElement? HostConfig { get; }
 
         /// <summary>
         /// Passed to the underlying <see cref="RuntimePluginLoader"/>
         /// holding plugins
         /// </summary>
-        public readonly ILogProvider? PluginErrorLog { get; init; }
+        ILogProvider? PluginErrorLog { get; }
 
         /// <summary>
-        /// If hot-reload is enabled, sets a time delay the file watcher waits when 
-        /// a plugin assembly has changed.
+        /// A factory instance the provides new <see cref="IPluginAssemblyLoader"/> instances
+        /// on demand from its plugin assembly path
         /// </summary>
-        public readonly TimeSpan ReloadDelay { get; init; }
+        public IPluginAssemblyLoaderFactory AssemblyLoaderFactory { get; init; }
     }
 }
diff --git a/lib/Plugins.Essentials.ServiceStack/src/PluginManager.cs b/lib/Plugins.Essentials.ServiceStack/src/PluginManager.cs
index e4e5670..2013a58 100644
--- a/lib/Plugins.Essentials.ServiceStack/src/PluginManager.cs
+++ b/lib/Plugins.Essentials.ServiceStack/src/PluginManager.cs
@@ -66,7 +66,7 @@ namespace VNLib.Plugins.Essentials.ServiceStack
 
         /// <inheritdoc/>
         /// <exception cref="ObjectDisposedException"></exception>
-        public Task LoadPluginsAsync(PluginLoadConfiguration config, ILogProvider appLog)
+        public void LoadPlugins(IPluginLoadConfiguration config, ILogProvider appLog)
         {
             Check();            
 
@@ -76,10 +76,10 @@ namespace VNLib.Plugins.Essentials.ServiceStack
             if (!dir.Exists)
             {
                 appLog.Warn("Plugin directory {dir} does not exist. No plugins were loaded", config.PluginDir);
-                return Task.CompletedTask;
+                return;
             }
 
-            appLog.Information("Loading plugins. Hot-reload: {en}", config.HotReload);
+            appLog.Information("Loading managed plugins");
 
             //Enumerate all dll files within this dir
             IEnumerable<DirectoryInfo> dirs = dir.EnumerateDirectories("*", SearchOption.TopDirectoryOnly);
@@ -91,14 +91,21 @@ namespace VNLib.Plugins.Essentials.ServiceStack
 
             appLog.Debug("Found plugin files: \n{files}", string.Concat(pluginFileNames));
 
-            //Initialze plugin managers
-            ManagedPlugin[] wrappers = pluginPaths.Select(pw => new ManagedPlugin(pw, config, this)).ToArray();
+            /*
+             * We need to get the assembly loader for the plugin file, then create its 
+             * RuntimePluginLoader which will be passed to the Managed plugin instance
+             */
+
+            ManagedPlugin[] wrappers = pluginPaths.Select(pw => config.AssemblyLoaderFactory.GetLoaderForPluginFile(pw))
+                                        .Select(l => new RuntimePluginLoader(l, config.HostConfig, config.PluginErrorLog))
+                                        .Select(loader => new ManagedPlugin(loader, this))
+                                        .ToArray();
 
             //Add to loaded plugins
             _plugins.AddRange(wrappers);
 
             //Load plugins
-            return InitiailzeAndLoadAsync(appLog);
+            InitiailzeAndLoad(appLog);
         }
 
         private static IEnumerable<string> GetPluginPaths(IEnumerable<DirectoryInfo> dirs)
@@ -118,13 +125,10 @@ namespace VNLib.Plugins.Essentials.ServiceStack
             });
         }
 
-        private async Task InitiailzeAndLoadAsync(ILogProvider debugLog) 
+        private void InitiailzeAndLoad(ILogProvider debugLog) 
         {
             //Load all async
-            Task[] initAll = _plugins.Select(p => InitializePlugin(p, debugLog)).ToArray();
-
-            //Wait for initalization
-            await Task.WhenAll(initAll).ConfigureAwait(false);
+            _plugins.ToArray().TryForeach(p => InitializePlugin(p, debugLog));           
 
             //Load stage, load all multithreaded
             Parallel.ForEach(_plugins, p => LoadPlugin(p, debugLog));
@@ -132,7 +136,7 @@ namespace VNLib.Plugins.Essentials.ServiceStack
             debugLog.Information("Plugin loading completed");
         }
 
-        private async Task InitializePlugin(ManagedPlugin plugin, ILogProvider debugLog)
+        private void InitializePlugin(ManagedPlugin plugin, ILogProvider debugLog)
         {
             void LogAndRemovePlugin(Exception ex)
             {
@@ -151,11 +155,7 @@ namespace VNLib.Plugins.Essentials.ServiceStack
             try
             {
                 //Load wrapper
-                await plugin.InitializePluginsAsync().ConfigureAwait(true);
-            }
-            catch(AggregateException ae) when (ae.InnerException != null) 
-            {
-                LogAndRemovePlugin(ae.InnerException);
+                plugin.InitializePlugins();
             }
             catch (Exception ex)
             {