/*
* Copyright (c) 2024 Vaughn Nugent
*
* Library: VNLib
* Package: VNLib.Plugins.Extensions.VNCache
* File: WriteBackCachePolicy.cs
*
* WriteBackCachePolicy.cs is part of VNLib.Plugins.Extensions.VNCache
* which is part of the larger VNLib collection of libraries and utilities.
*
* VNLib.Plugins.Extensions.VNCache 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.VNCache 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.Tasks;
using System.Diagnostics;
namespace VNLib.Plugins.Extensions.VNCache.DataModel
{
///
/// Provides a policy for observing the completion of cache operations
///
///
/// A callback function that is executed when a cache operation has fauled due to an exception
///
public class WriteBackCachePolicy(Action onFaulted) : ICacheTaskPolicy
{
///
public Task ObserveOperationAsync(Task operation)
{
ArgumentNullException.ThrowIfNull(operation);
if (!operation.IsCompleted)
{
//Defer the observation to the callback function to watch for errors
_ = operation.ContinueWith(
ObserveOperation,
cancellationToken: default,
TaskContinuationOptions.ExecuteSynchronously,
TaskScheduler.Default
);
}
return Task.CompletedTask;
}
private void ObserveOperation(Task operation)
{
//Should only be called on a completed task
Debug.Assert(operation.IsCompleted);
if (operation.IsFaulted)
{
onFaulted(operation);
}
}
}
}