/*
* Copyright (c) 2023 Vaughn Nugent
*
* Library: VNLib
* Package: VNLib.Data.Caching.ObjectCache
* File: BlobCacheBucket.cs
*
* BlobCacheBucket.cs is part of VNLib.Data.Caching.ObjectCache which is part of the larger
* VNLib collection of libraries and utilities.
*
* VNLib.Data.Caching.ObjectCache 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.Data.Caching.ObjectCache 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.Threading;
using System.Threading.Tasks;
using VNLib.Utils.Memory;
namespace VNLib.Data.Caching.ObjectCache
{
public sealed class BlobCacheBucket : IBlobCacheBucket
{
private readonly IBlobCache _cacheTable;
private readonly SemaphoreSlim _lock;
///
/// Initialzies a new and its underlying
///
///
///
/// The maxium number of entries allowed in the LRU cache
/// before LRU overflow happens.
///
/// The heap to allocate object cache buffers
public BlobCacheBucket(int bucketCapacity, IUnmangedHeap heap)
{
_lock = new(1, 1);
_cacheTable = new BlobCache(bucketCapacity, heap);
}
///
public void Dispose()
{
_cacheTable.Dispose();
_lock.Dispose();
}
///
public async ValueTask ManualWaitAsync(CancellationToken cancellation)
{
//try to enter the lock synchronously
if (_lock.Wait(0, CancellationToken.None))
{
return _cacheTable;
}
else
{
await _lock.WaitAsync(cancellation).ConfigureAwait(false);
return _cacheTable;
}
}
///
public void Release()
{
_lock.Release();
}
///
public async ValueTask WaitAsync(CancellationToken cancellation)
{
//try to enter the lock synchronously
if (_lock.Wait(0, CancellationToken.None))
{
return new(this, _cacheTable);
}
else
{
await _lock.WaitAsync(cancellation).ConfigureAwait(false);
return new(this, _cacheTable);
}
}
}
}