Aligned Blob (#16)

fix#15

Author: Seng-Jik

Core/Blob.h

@@ -14,32 +14,65 @@ namespace Snowing
 		size_t size_;
 
 		bool owner_;
+		bool aligned_;
 
 		inline Blob(std::uint8_t* bytes, size_t size, bool owner) noexcept :
 			bytes_{ bytes },
 			size_{ size },
-			owner_{ owner }
+			owner_{ owner },
+			aligned_{ false }
 		{}
 
 	public:
 		inline Blob():
 			bytes_{ nullptr },
 			size_{ 0 },
-			owner_{ false }
+			owner_{ false },
+			aligned_{ false }
 		{}
 
 		explicit inline Blob(size_t size) :
 			bytes_{ new std::uint8_t[size] },
 			size_{ size },
-			owner_{ true }
+			owner_{ true },
+			aligned_{ false }
 		{
 			assert(size);
 		}
 
+		inline Blob(size_t size, size_t alignment):
+			size_{ size },
+			owner_{ true },
+			aligned_{ true }
+		{
+			size_t offset, shift, alignedAddress;
+			void* allocation;
+			void** preamble;
+
+			offset = alignment - 1 + sizeof(void*);
+
+			allocation = static_cast<void*>(new uint8_t[size + static_cast<uint32_t>(offset)]);
+
+			alignedAddress = reinterpret_cast<size_t>(allocation) + sizeof(void*);
+
+			shift = alignedAddress % alignment;
+
+			if (shift)
+			{
+				alignedAddress += (alignment - shift);
+			}
+
+			preamble = reinterpret_cast<void**>(alignedAddress);
+			preamble[-1] = allocation;
+
+			bytes_ = reinterpret_cast<uint8_t*>(alignedAddress);
+		}
+
 		inline Blob(std::vector<uint8_t>* blob,bool copyAndOwner = true):
 			bytes_{ blob->data() },
 			size_{ blob->size() },
-			owner_{ copyAndOwner }
+			owner_{ copyAndOwner },
+			aligned_{ false }
 		{
 			if (owner_)
 			{
@@ -50,8 +83,17 @@ namespace Snowing
 
 		inline ~Blob() noexcept
 		{
-			if(owner_)
-				delete[] bytes_;
+			if (owner_)
+			{
+				if (!aligned_)
+					delete[] bytes_;
+				else
+				{
+					void** preamble = reinterpret_cast<void**>(bytes_);
+					delete [] reinterpret_cast<uint8_t*>(preamble[-1]);
+				}
+			}
+				
 		}
 
 		[[nodiscard]]
@@ -66,11 +108,13 @@ namespace Snowing
 		inline Blob(Blob&& b) noexcept :
 			bytes_{ b.bytes_ },
 			size_{ b.size_ },
-			owner_{ b.owner_ }
+			owner_{ b.owner_ },
+			aligned_{ b.aligned_ }
 		{
 			b.size_ = 0;
 			b.bytes_ = nullptr;
 			b.owner_ = false;
+			b.aligned_ = false;
 		}
 
 		Blob& operator= (const Blob&) = delete;
@@ -84,10 +128,14 @@ namespace Snowing
 			bytes_ = b.bytes_;
 			size_ = b.size_;
 			owner_ = b.owner_;
+			aligned_ = b.aligned_;
 
 			b.bytes_ = nullptr;
 			b.size_ = 0;
 			b.owner_ = false;
+			b.aligned_ = false;
+
+			return *this;
 		}
 
 		template <typename TPointer>

WindowsImpl/AssetLoader.cpp

@@ -3,7 +3,7 @@
 
 using namespace Snowing;
 
-Blob Snowing::PlatformImpls::WindowsImpl::ReadFile(const char * fileName)
+Blob Snowing::PlatformImpls::WindowsImpl::ReadFile(const char * fileName,size_t alignment)
 {
 	std::ifstream in{ fileName,std::ios::binary };
 
@@ -21,7 +21,12 @@ Blob Snowing::PlatformImpls::WindowsImpl::ReadFile(const char * fileName)
 	in.seekg(0, std::ios::end);
 	const auto size = static_cast<size_t>(in.tellg());
 
-	Blob b{ size };
+	Blob b;
+
+	if (alignment)
+		b = Blob{ size,alignment };
+	else
+		b = Blob{ size };
 
 	in.seekg(0, std::ios::beg);
 	in.read(b.Get<char*>(), size);
@@ -30,12 +35,12 @@ Blob Snowing::PlatformImpls::WindowsImpl::ReadFile(const char * fileName)
 	return b;
 }
 
-Blob Snowing::PlatformImpls::WindowsImpl::ReadFile(const wchar_t * fileName)
+Blob Snowing::PlatformImpls::WindowsImpl::ReadFile(const wchar_t * fileName, size_t alignment)
 {
 	char fileNameA[64];
 	char *pFileNameA = fileNameA;
 	while (*fileName)
 		*pFileNameA++ = static_cast<char>(*fileName++);
 	*pFileNameA = 0;
-	return Snowing::PlatformImpls::WindowsImpl::ReadFile(fileNameA);
+	return Snowing::PlatformImpls::WindowsImpl::ReadFile(fileNameA, alignment);
 }

WindowsImpl/AssetLoader.h

@@ -4,8 +4,8 @@
 namespace Snowing::PlatformImpls::WindowsImpl
 {
 	[[nodiscard]]
-	Blob ReadFile(const char* fileName);
+	Blob ReadFile(const char* fileName,size_t alignment = 0);
 
 	[[nodiscard]]
-	Blob ReadFile(const wchar_t* fileName);
+	Blob ReadFile(const wchar_t* fileName,size_t alignment = 0);
 }

WindowsImpl/PlatformImpls.h

@@ -23,9 +23,9 @@ namespace Snowing
 #ifndef PUBLISH_MODE
 	template <typename TChar>
 	[[nodiscard]]
-	inline Blob LoadAsset(const TChar* name)
+	inline Blob LoadAsset(const TChar* name, size_t alignment = 0)
 	{
-		return Snowing::PlatformImpls::WindowsImpl::ReadFile(name);
+		return Snowing::PlatformImpls::WindowsImpl::ReadFile(name, alignment);
 	}
 #endif
 }