Adjusted cache to allow for throttling and locking.

Harmonia.Core/Caching/AudioImageMemoryCache.cs

@@ -1,12 +1,19 @@
 using Harmonia.Core.Imaging;
 using Harmonia.Core.Models;
+using Microsoft.Extensions.Caching.Memory;
 
 namespace Harmonia.Core.Caching;
 
 public class AudioImageMemoryCache(IAudioImageExtractor audioImageExtractor) : MemoryCache<Song, SongPictureInfo>, IAudioImageCache
 {
-    protected override long? SizeLimit => 2000000000;
-    protected override double CompactionPercentage => 0.2;
+    protected override int MaxConcurrentRequests => 8;
+
+    protected override MemoryCacheOptions Options => new()
+    {
+        SizeLimit = 2000000000,
+        CompactionPercentage = 0.2,
+    };
+
     protected override TimeSpan SlidingExpiration => TimeSpan.FromSeconds(600);
 
     protected override object? GetKey(Song key)
@@ -23,14 +30,11 @@ public class AudioImageMemoryCache(IAudioImageExtractor audioImageExtractor) : M
         return null;
     }
 
-    protected override SongPictureInfo? Fetch(Song key)
+    protected override ValueTask<SongPictureInfo?> FetchAsync(Song key, CancellationToken cancellationToken)
     {
-        return audioImageExtractor.ExtractImage(key.FileName);
-    }
+        SongPictureInfo? songPictureInfo = audioImageExtractor.ExtractImage(key.FileName);
 
-    protected override void AddToCache(object key, SongPictureInfo entry)
-    {
-        base.AddToCache(key, entry);
+        return ValueTask.FromResult(songPictureInfo);
     }
 
     protected override long GetEntrySize(SongPictureInfo entry)