1 files changed, 256 insertions, 0 deletions
diff --git a/src/Ryujinx.Graphics.Gpu/Image/AutoDeleteCache.cs b/src/Ryujinx.Graphics.Gpu/Image/AutoDeleteCache.cs
new file mode 100644
index 00000000..a0b9f57b
--- /dev/null
+++ b/src/Ryujinx.Graphics.Gpu/Image/AutoDeleteCache.cs
@@ -0,0 +1,256 @@
+using System.Collections;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+
+namespace Ryujinx.Graphics.Gpu.Image
+{
+    /// <summary>
+    /// An entry on the short duration texture cache.
+    /// </summary>
+    class ShortTextureCacheEntry
+    {
+        public readonly TextureDescriptor Descriptor;
+        public readonly int InvalidatedSequence;
+        public readonly Texture Texture;
+
+        /// <summary>
+        /// Create a new entry on the short duration texture cache.
+        /// </summary>
+        /// <param name="descriptor">Last descriptor that referenced the texture</param>
+        /// <param name="texture">The texture</param>
+        public ShortTextureCacheEntry(TextureDescriptor descriptor, Texture texture)
+        {
+            Descriptor = descriptor;
+            InvalidatedSequence = texture.InvalidatedSequence;
+            Texture = texture;
+        }
+    }
+
+    /// <summary>
+    /// A texture cache that automatically removes older textures that are not used for some time.
+    /// The cache works with a rotated list with a fixed size. When new textures are added, the
+    /// old ones at the bottom of the list are deleted.
+    /// </summary>
+    class AutoDeleteCache : IEnumerable<Texture>
+    {
+        private const int MinCountForDeletion = 32;
+        private const int MaxCapacity = 2048;
+        private const ulong MaxTextureSizeCapacity = 512 * 1024 * 1024; // MB;
+
+        private readonly LinkedList<Texture> _textures;
+        private ulong _totalSize;
+
+        private HashSet<ShortTextureCacheEntry> _shortCacheBuilder;
+        private HashSet<ShortTextureCacheEntry> _shortCache;
+
+        private Dictionary<TextureDescriptor, ShortTextureCacheEntry> _shortCacheLookup;
+
+        /// <summary>
+        /// Creates a new instance of the automatic deletion cache.
+        /// </summary>
+        public AutoDeleteCache()
+        {
+            _textures = new LinkedList<Texture>();
+
+            _shortCacheBuilder = new HashSet<ShortTextureCacheEntry>();
+            _shortCache = new HashSet<ShortTextureCacheEntry>();
+
+            _shortCacheLookup = new Dictionary<TextureDescriptor, ShortTextureCacheEntry>();
+        }
+
+        /// <summary>
+        /// Adds a new texture to the cache, even if the texture added is already on the cache.
+        /// </summary>
+        /// <remarks>
+        /// Using this method is only recommended if you know that the texture is not yet on the cache,
+        /// otherwise it would store the same texture more than once.
+        /// </remarks>
+        /// <param name="texture">The texture to be added to the cache</param>
+        public void Add(Texture texture)
+        {
+            _totalSize += texture.Size;
+
+            texture.IncrementReferenceCount();
+            texture.CacheNode = _textures.AddLast(texture);
+
+            if (_textures.Count > MaxCapacity ||
+                (_totalSize > MaxTextureSizeCapacity && _textures.Count >= MinCountForDeletion))
+            {
+                RemoveLeastUsedTexture();
+            }
+        }
+
+        /// <summary>
+        /// Adds a new texture to the cache, or just moves it to the top of the list if the
+        /// texture is already on the cache.
+        /// </summary>
+        /// <remarks>
+        /// Moving the texture to the top of the list prevents it from being deleted,
+        /// as the textures on the bottom of the list are deleted when new ones are added.
+        /// </remarks>
+        /// <param name="texture">The texture to be added, or moved to the top</param>
+        public void Lift(Texture texture)
+        {
+            if (texture.CacheNode != null)
+            {
+                if (texture.CacheNode != _textures.Last)
+                {
+                    _textures.Remove(texture.CacheNode);
+
+                    texture.CacheNode = _textures.AddLast(texture);
+                }
+
+                if (_totalSize > MaxTextureSizeCapacity && _textures.Count >= MinCountForDeletion)
+                {
+                    RemoveLeastUsedTexture();
+                }
+            }
+            else
+            {
+                Add(texture);
+            }
+        }
+
+        /// <summary>
+        /// Removes the least used texture from the cache.
+        /// </summary>
+        private void RemoveLeastUsedTexture()
+        {
+            Texture oldestTexture = _textures.First.Value;
+
+            _totalSize -= oldestTexture.Size;
+
+            if (!oldestTexture.CheckModified(false))
+            {
+                // The texture must be flushed if it falls out of the auto delete cache.
+                // Flushes out of the auto delete cache do not trigger write tracking,
+                // as it is expected that other overlapping textures exist that have more up-to-date contents.
+
+                oldestTexture.Group.SynchronizeDependents(oldestTexture);
+                oldestTexture.FlushModified(false);
+            }
+
+            _textures.RemoveFirst();
+
+            oldestTexture.DecrementReferenceCount();
+            oldestTexture.CacheNode = null;
+        }
+
+        /// <summary>
+        /// Removes a texture from the cache.
+        /// </summary>
+        /// <param name="texture">The texture to be removed from the cache</param>
+        /// <param name="flush">True to remove the texture if it was on the cache</param>
+        /// <returns>True if the texture was found and removed, false otherwise</returns>
+        public bool Remove(Texture texture, bool flush)
+        {
+            if (texture.CacheNode == null)
+            {
+                return false;
+            }
+
+            // Remove our reference to this texture.
+            if (flush)
+            {
+                texture.FlushModified(false);
+            }
+
+            _textures.Remove(texture.CacheNode);
+
+            _totalSize -= texture.Size;
+
+            texture.CacheNode = null;
+
+            return texture.DecrementReferenceCount();
+        }
+
+        /// <summary>
+        /// Attempt to find a texture on the short duration cache.
+        /// </summary>
+        /// <param name="descriptor">The texture descriptor</param>
+        /// <returns>The texture if found, null otherwise</returns>
+        public Texture FindShortCache(in TextureDescriptor descriptor)
+        {
+            if (_shortCacheLookup.Count > 0 && _shortCacheLookup.TryGetValue(descriptor, out var entry))
+            {
+                if (entry.InvalidatedSequence == entry.Texture.InvalidatedSequence)
+                {
+                    return entry.Texture;
+                }
+                else
+                {
+                    _shortCacheLookup.Remove(descriptor);
+                }
+            }
+
+            return null;
+        }
+
+        /// <summary>
+        /// Removes a texture from the short duration cache.
+        /// </summary>
+        /// <param name="texture">Texture to remove from the short cache</param>
+        public void RemoveShortCache(Texture texture)
+        {
+            bool removed = _shortCache.Remove(texture.ShortCacheEntry);
+            removed |= _shortCacheBuilder.Remove(texture.ShortCacheEntry);
+
+            if (removed)
+            {
+                texture.DecrementReferenceCount();
+
+                _shortCacheLookup.Remove(texture.ShortCacheEntry.Descriptor);
+                texture.ShortCacheEntry = null;
+            }
+        }
+
+        /// <summary>
+        /// Adds a texture to the short duration cache.
+        /// It starts in the builder set, and it is moved into the deletion set on next process.
+        /// </summary>
+        /// <param name="texture">Texture to add to the short cache</param>
+        /// <param name="descriptor">Last used texture descriptor</param>
+        public void AddShortCache(Texture texture, ref TextureDescriptor descriptor)
+        {
+            var entry = new ShortTextureCacheEntry(descriptor, texture);
+
+            _shortCacheBuilder.Add(entry);
+            _shortCacheLookup.Add(entry.Descriptor, entry);
+
+            texture.ShortCacheEntry = entry;
+
+            texture.IncrementReferenceCount();
+        }
+
+        /// <summary>
+        /// Delete textures from the short duration cache.
+        /// Moves the builder set to be deleted on next process.
+        /// </summary>
+        public void ProcessShortCache()
+        {
+            HashSet<ShortTextureCacheEntry> toRemove = _shortCache;
+
+            foreach (var entry in toRemove)
+            {
+                entry.Texture.DecrementReferenceCount();
+
+                _shortCacheLookup.Remove(entry.Descriptor);
+                entry.Texture.ShortCacheEntry = null;
+            }
+
+            toRemove.Clear();
+            _shortCache = _shortCacheBuilder;
+            _shortCacheBuilder = toRemove;
+        }
+
+        public IEnumerator<Texture> GetEnumerator()
+        {
+            return _textures.GetEnumerator();
+        }
+
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            return _textures.GetEnumerator();
+        }
+    }
+}
+\ No newline at end of file