From 1e046c00333fe3799e63663acc01147cff107d33 Mon Sep 17 00:00:00 2001
From: Wojciech Figat <wojtek@figat.pl>
Date: Fri, 6 Jan 2023 08:56:03 +0100
Subject: [PATCH] Optimize GPU Resource name to prevent memory allocs when
 changing name frequently

---
 Source/Engine/Graphics/GPUDevice.cpp          | 28 +++++++++++++++----
 Source/Engine/Graphics/GPUResource.h          |  7 +++--
 Source/Engine/Graphics/GPUSwapChain.cpp       |  2 +-
 .../DirectX/DX12/GPUBufferDX12.cpp            |  2 +-
 .../GraphicsDevice/Vulkan/GPUBufferVulkan.cpp |  2 +-
 5 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/Source/Engine/Graphics/GPUDevice.cpp b/Source/Engine/Graphics/GPUDevice.cpp
index 16f13d522..6332aa9e1 100644
--- a/Source/Engine/Graphics/GPUDevice.cpp
+++ b/Source/Engine/Graphics/GPUDevice.cpp
@@ -195,7 +195,11 @@ GPUResource::~GPUResource()
 {
 #if !BUILD_RELEASE && GPU_ENABLE_RESOURCE_NAMING
     if (_memoryUsage != 0)
-        LOG(Error, "{0} '{1}' has not been disposed before destruction", ScriptingObject::ToString(), _name);
+        LOG(Error, "{0} '{1}' has not been disposed before destruction", ScriptingObject::ToString(), GetName());
+#endif
+#if GPU_ENABLE_RESOURCE_NAMING
+    if (_namePtr)
+        Platform::Free(_namePtr);
 #endif
 }
 
@@ -208,14 +212,26 @@ static_assert((GPU_ENABLE_RESOURCE_NAMING) == (!BUILD_RELEASE), "Update build co
 
 #if GPU_ENABLE_RESOURCE_NAMING
 
-String GPUResource::GetName() const
+StringView GPUResource::GetName() const
 {
-    return _name;
+    return StringView(_namePtr, _nameSize);
 }
 
 void GPUResource::SetName(const StringView& name)
 {
-    _name = name;
+    if (_nameCapacity < name.Length() + 1)
+    {
+        if (_namePtr)
+            Platform::Free(_namePtr);
+        _nameCapacity = name.Length() + 1;
+        _namePtr = (Char*)Platform::Allocate(_nameCapacity * sizeof(Char), 16);
+    }
+    _nameSize = name.Length();
+    if (name.HasChars())
+    {
+        Platform::MemoryCopy(_namePtr, name.Get(), _nameSize * sizeof(Char));
+        _namePtr[_nameSize] = 0;
+    }
 }
 
 #endif
@@ -243,8 +259,8 @@ void GPUResource::OnReleaseGPU()
 String GPUResource::ToString() const
 {
 #if GPU_ENABLE_RESOURCE_NAMING
-    if (_name.HasChars())
-        return _name;
+    if (_namePtr)
+        return String(_namePtr, _nameSize);
 #endif
     return ScriptingObject::ToString();
 }
diff --git a/Source/Engine/Graphics/GPUResource.h b/Source/Engine/Graphics/GPUResource.h
index 5e27d679b..434220fa7 100644
--- a/Source/Engine/Graphics/GPUResource.h
+++ b/Source/Engine/Graphics/GPUResource.h
@@ -49,7 +49,8 @@ API_CLASS(Abstract, NoSpawn) class FLAXENGINE_API GPUResource : public Scripting
 protected:
     uint64 _memoryUsage = 0;
 #if GPU_ENABLE_RESOURCE_NAMING
-    String _name;
+    Char* _namePtr = nullptr;
+    int32 _nameSize = 0, _nameCapacity = 0;
 #endif
 
 public:
@@ -95,7 +96,7 @@ public:
     /// <summary>
     /// Gets the resource name.
     /// </summary>
-    API_PROPERTY() String GetName() const;
+    API_PROPERTY() StringView GetName() const;
 
     /// <summary>
     /// Sets the resource name.
@@ -149,7 +150,7 @@ public:
     {
 #if GPU_ENABLE_RESOURCE_NAMING
         if (name.HasChars())
-            GPUResource::_name = name;
+            GPUResource::SetName(name);
 #endif
         device->AddResource(this);
     }
diff --git a/Source/Engine/Graphics/GPUSwapChain.cpp b/Source/Engine/Graphics/GPUSwapChain.cpp
index 43a2582ca..31f751fcb 100644
--- a/Source/Engine/Graphics/GPUSwapChain.cpp
+++ b/Source/Engine/Graphics/GPUSwapChain.cpp
@@ -38,7 +38,7 @@ public:
 GPUSwapChain::GPUSwapChain()
 {
 #if GPU_ENABLE_RESOURCE_NAMING
-    _name = TEXT("Swap Chain (backbuffers)");
+    SetName(TEXT("Swap Chain (backbuffers)"));
 #endif
 }
 
diff --git a/Source/Engine/GraphicsDevice/DirectX/DX12/GPUBufferDX12.cpp b/Source/Engine/GraphicsDevice/DirectX/DX12/GPUBufferDX12.cpp
index e13f30dc8..b82dbd9fd 100644
--- a/Source/Engine/GraphicsDevice/DirectX/DX12/GPUBufferDX12.cpp
+++ b/Source/Engine/GraphicsDevice/DirectX/DX12/GPUBufferDX12.cpp
@@ -175,7 +175,7 @@ bool GPUBufferDX12::OnInit()
     if (_desc.Flags & GPUBufferFlags::Counter || _desc.Flags & GPUBufferFlags::Append)
     {
 #if GPU_ENABLE_RESOURCE_NAMING
-        String name = GetName() + TEXT(".Counter");
+        String name = String(GetName()) + TEXT(".Counter");
         _counter = ::New<GPUBufferDX12>(_device, name);
 #else
         _counter = ::New<GPUBufferDX12>(_device, String::Empty);
diff --git a/Source/Engine/GraphicsDevice/Vulkan/GPUBufferVulkan.cpp b/Source/Engine/GraphicsDevice/Vulkan/GPUBufferVulkan.cpp
index e4e432f98..bfc88c14c 100644
--- a/Source/Engine/GraphicsDevice/Vulkan/GPUBufferVulkan.cpp
+++ b/Source/Engine/GraphicsDevice/Vulkan/GPUBufferVulkan.cpp
@@ -165,7 +165,7 @@ bool GPUBufferVulkan::OnInit()
     if (_desc.Flags & GPUBufferFlags::Counter || _desc.Flags & GPUBufferFlags::Append)
     {
 #if GPU_ENABLE_RESOURCE_NAMING
-        String name = GetName() + TEXT(".Counter");
+        String name = String(GetName()) + TEXT(".Counter");
         Counter = ::New<GPUBufferVulkan>(_device, name);
 #else
 		Counter = ::New<GPUBufferVulkan>(_device, StringView::Empty);