jellyfin/Emby.Server.Implementations/ScheduledTasks/Triggers/IntervalTrigger.cs
2022-12-05 15:00:20 +01:00

124 lines
3.4 KiB
C#

using System;
using System.Linq;
using System.Threading;
using MediaBrowser.Model.Tasks;
using Microsoft.Extensions.Logging;
namespace Emby.Server.Implementations.ScheduledTasks.Triggers
{
/// <summary>
/// Represents a task trigger that runs repeatedly on an interval.
/// </summary>
public sealed class IntervalTrigger : ITaskTrigger, IDisposable
{
private readonly TimeSpan _interval;
private DateTime _lastStartDate;
private Timer? _timer;
private bool _disposed = false;
/// <summary>
/// Initializes a new instance of the <see cref="IntervalTrigger"/> class.
/// </summary>
/// <param name="interval">The interval.</param>
/// <param name="taskOptions">The options of this task.</param>
public IntervalTrigger(TimeSpan interval, TaskOptions taskOptions)
{
_interval = interval;
TaskOptions = taskOptions;
}
/// <summary>
/// Occurs when [triggered].
/// </summary>
public event EventHandler<EventArgs>? Triggered;
/// <summary>
/// Gets the options of this task.
/// </summary>
public TaskOptions TaskOptions { get; }
/// <summary>
/// Stars waiting for the trigger action.
/// </summary>
/// <param name="lastResult">The last result.</param>
/// <param name="logger">The logger.</param>
/// <param name="taskName">The name of the task.</param>
/// <param name="isApplicationStartup">if set to <c>true</c> [is application startup].</param>
public void Start(TaskResult? lastResult, ILogger logger, string taskName, bool isApplicationStartup)
{
DisposeTimer();
DateTime triggerDate;
if (lastResult is null)
{
// Task has never been completed before
triggerDate = DateTime.UtcNow.AddHours(1);
}
else
{
triggerDate = new[] { lastResult.EndTimeUtc, _lastStartDate }.Max().Add(_interval);
}
if (DateTime.UtcNow > triggerDate)
{
triggerDate = DateTime.UtcNow.AddMinutes(1);
}
var dueTime = triggerDate - DateTime.UtcNow;
var maxDueTime = TimeSpan.FromDays(7);
if (dueTime > maxDueTime)
{
dueTime = maxDueTime;
}
_timer = new Timer(_ => OnTriggered(), null, dueTime, TimeSpan.FromMilliseconds(-1));
}
/// <summary>
/// Stops waiting for the trigger action.
/// </summary>
public void Stop()
{
DisposeTimer();
}
/// <summary>
/// Disposes the timer.
/// </summary>
private void DisposeTimer()
{
_timer?.Dispose();
_timer = null;
}
/// <summary>
/// Called when [triggered].
/// </summary>
private void OnTriggered()
{
DisposeTimer();
if (Triggered != null)
{
_lastStartDate = DateTime.UtcNow;
Triggered(this, EventArgs.Empty);
}
}
/// <inheritdoc />
public void Dispose()
{
if (_disposed)
{
return;
}
DisposeTimer();
_disposed = true;
}
}
}