3 files changed, 35 insertions, 79 deletions

diff --git a/lib/Plugins.Runtime/src/AssemblyWatcher.cs b/lib/Plugins.Runtime/src/AssemblyWatcher.cs
index 09b49dc..69c53ed 100644
--- a/lib/Plugins.Runtime/src/AssemblyWatcher.cs
+++ b/lib/Plugins.Runtime/src/AssemblyWatcher.cs
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2023 Vaughn Nugent
+* Copyright (c) 2024 Vaughn Nugent
 * 
 * Library: VNLib
 * Package: VNLib.Plugins.Runtime
@@ -22,95 +22,52 @@
 * along with VNLib.Plugins.Runtime. If not, see http://www.gnu.org/licenses/.
 */
 
+using System;
 using System.IO;
 using System.Threading;
-using System.Collections.Generic;
 
 using VNLib.Utils;
+using VNLib.Utils.IO;
 using VNLib.Utils.Extensions;
 
-namespace VNLib.Plugins.Runtime
-{
-    internal sealed class AssemblyWatcher : IPluginAssemblyWatcher
-    {
-        private readonly object _lock = new ();
-        private readonly Dictionary<IPluginReloadEventHandler, AsmFileWatcher> _watchers;
 
-        public AssemblyWatcher()
-        {
-            _watchers = new();
-        }
+namespace VNLib.Plugins.Runtime
+{    
 
-        ///<inheritdoc/>
-        public void StopWatching(IPluginReloadEventHandler handler)
-        {
-            lock (_lock)
-            {
-                //Find old watcher by its handler, then dispose it
-                if (_watchers.Remove(handler, out AsmFileWatcher? watcher))
-                {
-                    //dispose the watcher
-                    watcher.Dispose();
-                }
-            }
-        }
+    internal static class AssemblyWatcher
+    {
 
-        ///<inheritdoc/>
-        public void WatchAssembly(IPluginReloadEventHandler handler, IPluginAssemblyLoader loader)
+        internal static IDisposable WatchAssembly(IPluginReloadEventHandler handler, IPluginAssemblyLoader loader)
         {
-            lock(_lock)
-            {
-                if(_watchers.Remove(handler, out AsmFileWatcher? watcher))
-                {
-                    //dispose the watcher
-                    watcher.Dispose();
-                }
+            ArgumentNullException.ThrowIfNull(handler);
+            ArgumentNullException.ThrowIfNull(loader);
 
-                //Queue up a new watcher
-                watcher = new(loader, handler);
+            DebouncedFSEventHandler dbh = new(loader, handler);
+            FileWatcher.Subscribe(loader.Config.AssemblyFile, dbh);
 
-                //Store watcher
-                _watchers.Add(handler, watcher);
-            }
+            return dbh;
         }
 
-        private sealed class AsmFileWatcher : VnDisposeable
+        internal sealed class DebouncedFSEventHandler : VnDisposeable, IFSChangeHandler
         {
-            public IPluginReloadEventHandler Handler { get; }
 
+            private readonly IPluginReloadEventHandler _handler;
             private readonly IPluginAssemblyLoader _loaderSource;
             private readonly Timer _delayTimer;
-            private readonly FileSystemWatcher _watcher;
 
             private bool _pause;
 
-            public AsmFileWatcher(IPluginAssemblyLoader LoaderSource, IPluginReloadEventHandler handler)
+            public DebouncedFSEventHandler(IPluginAssemblyLoader loader, IPluginReloadEventHandler handler)
             {
-                Handler = handler;
-                _loaderSource = LoaderSource;
-
-                string dir = Path.GetDirectoryName(LoaderSource.Config.AssemblyFile)!;
-
-                //Configure watcher to notify only when the assembly file changes
-                _watcher = new FileSystemWatcher(dir)
-                {
-                    Filter = "*.dll",
-                    EnableRaisingEvents = false,
-                    IncludeSubdirectories = true,
-                    NotifyFilter = NotifyFilters.LastWrite,
-                };
-
-                //Configure listener
-                _watcher.Changed += OnFileChanged;
-                _watcher.Created += OnFileChanged;
-
-                _watcher.EnableRaisingEvents = true;
+                _handler = handler;
+                _loaderSource = loader;
 
                 //setup delay timer to wait on the config
-                _delayTimer = new(OnTimeout, this, Timeout.InfiniteTimeSpan, Timeout.InfiniteTimeSpan);
+                _delayTimer = new(OnTimeout, null, Timeout.InfiniteTimeSpan, Timeout.InfiniteTimeSpan);
             }
 
-            void OnFileChanged(object sender, FileSystemEventArgs e)
+            ///<inheritdoc/>
+            void IFSChangeHandler.OnFileChanged(FileSystemEventArgs e)
             {
                 //if were already waiting to process an event, we dont need to stage another
                 if (_pause)
@@ -130,7 +87,7 @@ namespace VNLib.Plugins.Runtime
                 _delayTimer.Stop();
 
                 //Fire event, let exception crash app
-                Handler.OnPluginUnloaded(_loaderSource);
+                _handler.OnPluginUnloaded(_loaderSource);
 
                 //Clear pause flag
                 _pause = false;
@@ -140,9 +97,7 @@ namespace VNLib.Plugins.Runtime
             {
                 _delayTimer.Dispose();
 
-                //Detach event handler and dispose watcher
-                _watcher.Changed -= OnFileChanged;
-                _watcher.Dispose();
+                FileWatcher.Unsubscribe(_loaderSource.Config.AssemblyFile, this);
             }
         }
     }
diff --git a/lib/Plugins.Runtime/src/PluginStackBuilder.cs b/lib/Plugins.Runtime/src/PluginStackBuilder.cs
index eed08e2..ef3ffc9 100644
--- a/lib/Plugins.Runtime/src/PluginStackBuilder.cs
+++ b/lib/Plugins.Runtime/src/PluginStackBuilder.cs
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2023 Vaughn Nugent
+* Copyright (c) 2024 Vaughn Nugent
 * 
 * Library: VNLib
 * Package: VNLib.Plugins.Runtime
@@ -83,8 +83,10 @@ namespace VNLib.Plugins.Runtime
         /// <returns>The current builder instance for chaining</returns>
         public PluginStackBuilder WithConfigurationReader(IPluginConfigReader pluginConfig)
         {
+            ArgumentNullException.ThrowIfNull(pluginConfig);
+
             //Store binary copy
-            PluginConfig = pluginConfig ?? throw new ArgumentNullException(nameof(pluginConfig));
+            PluginConfig = pluginConfig;
             return this;
         }
 
diff --git a/lib/Plugins.Runtime/src/RuntimePluginLoader.cs b/lib/Plugins.Runtime/src/RuntimePluginLoader.cs
index 60edf55..23bbcab 100644
--- a/lib/Plugins.Runtime/src/RuntimePluginLoader.cs
+++ b/lib/Plugins.Runtime/src/RuntimePluginLoader.cs
@@ -38,10 +38,9 @@ namespace VNLib.Plugins.Runtime
     /// </summary>
     public sealed class RuntimePluginLoader : VnDisposeable, IPluginReloadEventHandler
     {
-        private static readonly IPluginAssemblyWatcher Watcher = new AssemblyWatcher();
-       
-        private readonly IPluginAssemblyLoader Loader;      
+        private readonly IPluginAssemblyLoader Loader;
         private readonly ILogProvider? Log;
+        private readonly IDisposable? Watcher;
 
         /// <summary>
         /// Gets the plugin assembly loader configuration information
@@ -61,13 +60,15 @@ namespace VNLib.Plugins.Runtime
         /// <exception cref="ArgumentNullException"></exception>
         public RuntimePluginLoader(IPluginAssemblyLoader loader, ILogProvider? log)
         {
-            Log = log;
-            Loader = loader ?? throw new ArgumentNullException(nameof(loader));
+            ArgumentNullException.ThrowIfNull(loader);
+            
+            Log = log;           
+            Loader = loader;
 
             //Configure watcher if requested
             if (loader.Config.WatchForReload)
             {
-                Watcher.WatchAssembly(this, loader);
+                Watcher = AssemblyWatcher.WatchAssembly(this, loader);
             }
 
             //Init container
@@ -200,10 +201,8 @@ namespace VNLib.Plugins.Runtime
         ///<inheritdoc/>
         protected override void Free()
         {
-            //Stop watching for events
-            Watcher.StopWatching(this);
-
             //Cleanup
+            Watcher?.Dispose();
             Controller.Dispose();
             Loader.Dispose();
         }