From d28c38a9d0b682a065e64d184604076fdda7d802 Mon Sep 17 00:00:00 2001
From: Alex Barney <thealexbarney@gmail.com>
Date: Tue, 8 Mar 2022 17:20:41 -0700
Subject: [PATCH] Add MemoryResourceBufferHoldStorage

---
 .../MemoryResourceBufferHoldStorage.cs        | 91 +++++++++++++++++++
 1 file changed, 91 insertions(+)
 create mode 100644 src/LibHac/FsSystem/MemoryResourceBufferHoldStorage.cs

diff --git a/src/LibHac/FsSystem/MemoryResourceBufferHoldStorage.cs b/src/LibHac/FsSystem/MemoryResourceBufferHoldStorage.cs
new file mode 100644
index 00000000..00f77c1c
--- /dev/null
+++ b/src/LibHac/FsSystem/MemoryResourceBufferHoldStorage.cs
@@ -0,0 +1,91 @@
+using System;
+using LibHac.Common;
+using LibHac.Diag;
+using LibHac.Fs;
+
+namespace LibHac.FsSystem;
+
+/// <summary>
+/// Allocates a buffer from the provided <see cref="MemoryResource"/> that is deallocated
+/// when the <see cref="MemoryResourceBufferHoldStorage"/> is disposed.
+/// </summary>
+/// <remarks>Based on FS 13.1.0 (nnSdk 13.4.0)</remarks>
+public class MemoryResourceBufferHoldStorage : IStorage
+{
+    private SharedRef<IStorage> _storage;
+    private MemoryResource _memoryResource;
+    private Mem.Buffer _buffer;
+
+    public MemoryResourceBufferHoldStorage(ref SharedRef<IStorage> baseStorage, MemoryResource memoryResource,
+        int bufferSize)
+    {
+        _storage = SharedRef<IStorage>.CreateMove(ref baseStorage);
+        _memoryResource = memoryResource;
+        _buffer = memoryResource.Allocate(bufferSize);
+    }
+
+    public override void Dispose()
+    {
+        if (!_buffer.IsNull)
+        {
+            _memoryResource.Deallocate(ref _buffer);
+        }
+
+        _storage.Destroy();
+
+        base.Dispose();
+    }
+
+    public bool IsValid()
+    {
+        return !_buffer.IsNull;
+    }
+
+    public Mem.Buffer GetBuffer()
+    {
+        return _buffer;
+    }
+
+    public override Result Read(long offset, Span<byte> destination)
+    {
+        Assert.SdkRequiresNotNull(_storage);
+
+        return _storage.Get.Read(offset, destination);
+    }
+
+    public override Result Write(long offset, ReadOnlySpan<byte> source)
+    {
+        Assert.SdkRequiresNotNull(_storage);
+
+        return _storage.Get.Write(offset, source);
+    }
+
+    public override Result Flush()
+    {
+        Assert.SdkRequiresNotNull(_storage);
+
+        return _storage.Get.Flush();
+    }
+
+    public override Result SetSize(long size)
+    {
+        Assert.SdkRequiresNotNull(_storage);
+
+        return _storage.Get.SetSize(size);
+    }
+
+    public override Result GetSize(out long size)
+    {
+        Assert.SdkRequiresNotNull(_storage);
+
+        return _storage.Get.GetSize(out size);
+    }
+
+    public override Result OperateRange(Span<byte> outBuffer, OperationId operationId, long offset, long size,
+        ReadOnlySpan<byte> inBuffer)
+    {
+        Assert.SdkRequiresNotNull(_storage);
+
+        return _storage.Get.OperateRange(outBuffer, operationId, offset, size, inBuffer);
+    }
+}
\ No newline at end of file