Restructure

1 files changed, 124 insertions, 0 deletions

diff --git a/lib/VNLib.Plugins.Extensions.Loading/src/Events/EventManagment.cs b/lib/VNLib.Plugins.Extensions.Loading/src/Events/EventManagment.cs
new file mode 100644
index 0000000..f671b07
--- /dev/null
+++ b/lib/VNLib.Plugins.Extensions.Loading/src/Events/EventManagment.cs
@@ -0,0 +1,124 @@
+/*
+* Copyright (c) 2022 Vaughn Nugent
+* 
+* Library: VNLib
+* Package: VNLib.Plugins.Extensions.Loading
+* File: EventManagment.cs 
+*
+* EventManagment.cs is part of VNLib.Plugins.Extensions.Loading which is part of the larger 
+* VNLib collection of libraries and utilities.
+*
+* VNLib.Plugins.Extensions.Loading 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.Extensions.Loading 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.Extensions.Loading. If not, see http://www.gnu.org/licenses/.
+*/
+
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+using VNLib.Utils.Logging;
+
+namespace VNLib.Plugins.Extensions.Loading.Events
+{
+
+    /// <summary>
+    /// A deletage to form a method signature for shedulable interval callbacks
+    /// </summary>
+    /// <param name="log">The plugin's default log provider</param>
+    /// <param name="pluginExitToken">The plugin's exit token</param>
+    /// <returns>A task the represents the asynchronous work</returns>
+    public delegate Task AsyncSchedulableCallback(ILogProvider log, CancellationToken pluginExitToken);
+
+    /// <summary>
+    /// Provides event schedueling extensions for plugins
+    /// </summary>
+    public static class EventManagment
+    {
+        /// <summary>
+        /// Schedules an asynchronous event interval for the current plugin, that is active until canceled or until the plugin unloads
+        /// </summary>
+        /// <param name="plugin"></param>
+        /// <param name="asyncCallback">An asyncrhonous callback method.</param>
+        /// <param name="interval">The event interval</param>
+        /// <param name="immediate">A value that indicates if the callback should be run as soon as possible</param>
+        /// <exception cref="ObjectDisposedException"></exception>
+        /// <remarks>If exceptions are raised during callback execution, they are written to the plugin's default log provider</remarks>
+        public static void ScheduleInterval(this PluginBase plugin, AsyncSchedulableCallback asyncCallback, TimeSpan interval, bool immediate = false)
+        {
+            plugin.ThrowIfUnloaded();
+            
+            plugin.Log.Verbose("Interval for {t} scheduled", interval);
+            
+            //Run interval on plugins bg scheduler
+            _ = plugin.DeferTask(() => RunIntervalOnPluginScheduler(plugin, asyncCallback, interval, immediate));
+        }
+
+        private static async Task RunIntervalOnPluginScheduler(PluginBase plugin, AsyncSchedulableCallback callback, TimeSpan interval, bool immediate)
+        {
+
+            static async Task RunCallbackAsync(PluginBase plugin, AsyncSchedulableCallback callback)
+            {
+                try
+                {
+                    //invoke interval callback
+                    await callback(plugin.Log, plugin.UnloadToken).ConfigureAwait(false);
+                }
+                catch (OperationCanceledException)
+                {
+                    //unloaded
+                    plugin.Log.Verbose("Interval callback canceled due to plugin unload or other event cancellation");
+                }
+                catch (Exception ex)
+                {
+                    plugin.Log.Error(ex, "Unhandled exception raised during timer callback");
+                }
+            }
+
+            //Run callback immediatly if requested
+            if (immediate)
+            {
+                await RunCallbackAsync(plugin, callback);
+            }
+
+            //Timer loop
+            while (true)
+            {
+                try
+                {
+                    //await delay and wait for plugin cancellation
+                    await Task.Delay(interval, plugin.UnloadToken);
+                }
+                catch (TaskCanceledException)
+                {
+                    //Unload token canceled, exit loop
+                    break;
+                }
+
+                await RunCallbackAsync(plugin, callback);
+            }
+        }
+
+        /// <summary>
+        /// Registers an <see cref="IIntervalScheduleable"/> type's event handler for 
+        /// raising timed interval events
+        /// </summary>
+        /// <param name="plugin"></param>
+        /// <param name="scheduleable">The instance to schedule for timeouts</param>
+        /// <param name="interval">The timeout interval</param>
+        /// <param name="immediate">A value that indicates if the callback should be run as soon as possible</param>
+        /// <exception cref="ObjectDisposedException"></exception>
+        /// <remarks>If exceptions are raised during callback execution, they are written to the plugin's default log provider</remarks>
+        public static void ScheduleInterval(this PluginBase plugin, IIntervalScheduleable scheduleable, TimeSpan interval, bool immediate = false) => 
+            ScheduleInterval(plugin, scheduleable.OnIntervalAsync, interval, immediate);
+    }
+}