PersistentFlushBuffer + BackgroundResources

src/Ryujinx.Graphics.Metal/PersistentFlushBuffer.cs

@@ -0,0 +1,66 @@
+using System;
+using System.Runtime.Versioning;
+
+namespace Ryujinx.Graphics.Metal
+{
+    [SupportedOSPlatform("macos")]
+    internal class PersistentFlushBuffer : IDisposable
+    {
+        private readonly MetalRenderer _renderer;
+        private readonly Pipeline _pipeline;
+
+        private BufferHolder _flushStorage;
+
+        public PersistentFlushBuffer(MetalRenderer renderer, Pipeline pipeline)
+        {
+            _renderer = renderer;
+            _pipeline = pipeline;
+        }
+
+        private BufferHolder ResizeIfNeeded(int size)
+        {
+            var flushStorage = _flushStorage;
+
+            if (flushStorage == null || size > _flushStorage.Size)
+            {
+                flushStorage?.Dispose();
+
+                flushStorage = _renderer.BufferManager.Create(size);
+                _flushStorage = flushStorage;
+            }
+
+            return flushStorage;
+        }
+
+        public Span<byte> GetBufferData(CommandBufferPool cbp, BufferHolder buffer, int offset, int size)
+        {
+            var flushStorage = ResizeIfNeeded(size);
+            Auto<DisposableBuffer> srcBuffer;
+
+            using (var cbs = cbp.Rent())
+            {
+                srcBuffer = buffer.GetBuffer();
+                var dstBuffer = flushStorage.GetBuffer();
+
+                if (srcBuffer.TryIncrementReferenceCount())
+                {
+                    BufferHolder.Copy(_pipeline, cbs, srcBuffer, dstBuffer, offset, 0, size, registerSrcUsage: false);
+                }
+                else
+                {
+                    // Source buffer is no longer alive, don't copy anything to flush storage.
+                    srcBuffer = null;
+                }
+            }
+
+            flushStorage.WaitForFences();
+            srcBuffer?.DecrementReferenceCount();
+            return flushStorage.GetDataStorage(0, size);
+        }
+
+        public void Dispose()
+        {
+            _flushStorage.Dispose();
+        }
+    }
+}