/*
* Copyright (c) 2024 Vaughn Nugent
*
* Library: VNLib
* Package: VNLib.Plugins.Extensions.VNCache
* File: EntityCacheExtensions.cs
*
* EntityCacheExtensions.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.Linq;
using System.Threading;
using System.Threading.Tasks;
namespace VNLib.Plugins.Extensions.VNCache.DataModel
{
///
/// A cache proxy that sits transparently between a backing store and the caller
/// to cache unique entities
///
///
/// The backing entity data store
/// The entity cache used to fetch
public class TransparentEntityCache(IEntityStore store, EntityResultCache cache) : IEntityStore
where TEntity : class
{
///
public Task GetAsync(TRequest request, CancellationToken cancellation = default)
where TRequest : IEntityCacheKey
{
return cache.FetchAsync(request, store.GetAsync, cancellation);
}
///
public Task RemoveAsync(TRequest request, CancellationToken cancellation = default)
where TRequest : IEntityCacheKey
{
Task _fromCache = cache.RemoveAsync(request, cancellation)
.ContinueWith(static (_) => true, TaskScheduler.Default);
Task _fromStore = store.RemoveAsync(request, cancellation);
return Task.WhenAll(_fromCache, _fromStore)
.ContinueWith(static (t) => t.Result.All(static r => r), TaskScheduler.Default);
}
///
public Task UpsertAsync(TRequest request, TEntity entity, CancellationToken cancellation = default)
where TRequest : IEntityCacheKey
{
//Remove key from cache but push update to store
Task _fromCache = cache.RemoveAsync(request, cancellation);
Task _fromStore = store.UpsertAsync(request, entity, cancellation);
return Task.WhenAll(_fromCache, _fromStore);
}
}
}