/*
* Copyright (c) 2024 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 Affero General Public License as
* published by the Free Software Foundation, either version 3 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 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.Threading;
using System.Threading.Tasks;
using VNLib.Utils.Logging;
namespace VNLib.Plugins.Extensions.Loading.Events
{
///
/// A deletage to form a method signature for shedulable interval callbacks
///
/// The plugin's default log provider
/// The plugin's exit token
/// A task the represents the asynchronous work
public delegate Task AsyncSchedulableCallback(ILogProvider log, CancellationToken pluginExitToken);
///
/// Provides event schedueling extensions for plugins
///
public static class EventManagment
{
///
/// Schedules an asynchronous event interval for the current plugin, that is active until canceled or until the plugin unloads
///
///
/// An asyncrhonous callback method.
/// The event interval
/// A value that indicates if the callback should be run as soon as possible
///
/// If exceptions are raised during callback execution, they are written to the plugin's default log provider
public static void ScheduleInterval(this PluginBase plugin, AsyncSchedulableCallback asyncCallback, TimeSpan interval, bool immediate = false)
{
plugin.ThrowIfUnloaded();
plugin.Log.Verbose("Interval for {t} scheduled on type {rr}", interval, asyncCallback.Target);
//Run interval on plugins bg scheduler
_ = plugin.ObserveWork(() => 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);
}
}
///
/// Registers an type's event handler for
/// raising timed interval events
///
///
/// The instance to schedule for timeouts
/// The timeout interval
/// A value that indicates if the callback should be run as soon as possible
///
/// If exceptions are raised during callback execution, they are written to the plugin's default log provider
public static void ScheduleInterval(this PluginBase plugin, IIntervalScheduleable scheduleable, TimeSpan interval, bool immediate = false) =>
ScheduleInterval(plugin, scheduleable.OnIntervalAsync, interval, immediate);
}
}