diff --git a/openVulkanoCpp/IO/Archive/ZipWriter.cpp b/openVulkanoCpp/IO/Archive/ZipWriter.cpp
index a9c1375..77994c4 100644
--- a/openVulkanoCpp/IO/Archive/ZipWriter.cpp
+++ b/openVulkanoCpp/IO/Archive/ZipWriter.cpp
@@ -12,6 +12,7 @@
 
 #include "ZipWriter.hpp"
 #include "Base/Utils.hpp"
+#include "IO/MemMappedFile.hpp"
 #include "Math/CRC32.hpp"
 
 #include <ctime>
@@ -71,6 +72,19 @@ namespace
 		uint64_t modTime;      // 64-bit NTFS file last modification time
 		uint64_t acTime;       // 64-bit NTFS file last access time
 		uint64_t crTime;       // 64-bit NTFS file creation time
+
+		static uint64_t TimetToWinFileTime(time_t t)
+		{
+			// See references for details
+			return (t * 10000000LL) + 116444736000000000LL;
+		}
+
+		NtfsExtraField(time_t modTime, time_t acTime, time_t crTime)
+		{
+			this->modTime = TimetToWinFileTime(modTime);
+			this->acTime = TimetToWinFileTime(acTime);
+			this->crTime = TimetToWinFileTime(crTime);
+		}
 	};
 
 	struct EndOfCentralDirectoryHeader
@@ -92,14 +106,6 @@ namespace
 	static_assert(sizeof(EndOfCentralDirectoryHeader) == 22, "Well packed struct");
 	static_assert(sizeof(NtfsExtraField) == 36, "Well packed struct");
 
-	template<typename T>
-	uint32_t Cat(std::vector<uint8_t>& dest, T* thing)
-	{
-		uint32_t startOffset = dest.size();
-		dest.insert(dest.end(), (uint8_t *)thing, (uint8_t *)(thing + 1));
-		return startOffset;
-	}
-
 	uint32_t Cat(std::vector<uint8_t>& dest, size_t size, uint8_t* thing)
 	{
 		uint32_t startOffset = dest.size();
@@ -107,16 +113,15 @@ namespace
 		return startOffset;
 	}
 
-	uint32_t Cat(std::vector<uint8_t>& dest, const std::vector<uint8_t>& thing)
+	template<typename T>
+	uint32_t Cat(std::vector<uint8_t>& dest, T* thing)
 	{
-		uint32_t startOffset = Cat(dest, thing.size(), (uint8_t*)thing.data());
-		return startOffset;
+		return Cat(dest, sizeof(T), reinterpret_cast<uint8_t*>(thing));
 	}
 
-	void TimetToFileTime(time_t t, uint64_t* lpWinFileTime)
+	uint32_t Cat(std::vector<uint8_t>& dest, const std::vector<uint8_t>& thing)
 	{
-		// See references for details
-		*lpWinFileTime = (t * 10000000LL) + 116444736000000000LL;
+		return Cat(dest, thing.size(), const_cast<uint8_t*>(thing.data()));
 	}
 
 	std::pair<uint16_t, uint16_t> ConvertToDosTimeDate(time_t time)
@@ -186,10 +191,7 @@ namespace OpenVulkano
 		cdfh.externalFileAttribs = 32; // NOTE(vb): I've no idea wtf is this value mean
 		cdfh.relativeOffsetOfLocalFileHeader = headerOffset;
 
-		NtfsExtraField ntfs;
-		TimetToFileTime(modTime, &ntfs.modTime);
-		TimetToFileTime(accessTime, &ntfs.acTime);
-		TimetToFileTime(createTime, &ntfs.crTime);
+		NtfsExtraField ntfs(modTime, accessTime, createTime);
 
 		Cat(m_centralDirs, &cdfh);
 		Cat(m_centralDirs, fileNameLength, fileName);
@@ -200,26 +202,29 @@ namespace OpenVulkano
 	
 	void ZipWriter::AddFile(const std::filesystem::path& fileName, const char* inArchiveName)
 	{
-		auto data = Utils::ReadFile(fileName.string());
-		auto desc = OpenVulkano::FileDescription::MakeDescriptionForFile(inArchiveName, data.Size());
-		AddFile(desc, data.Data());
+		MemMappedFile file = MemMappedFile(fileName.string());
+		auto desc = OpenVulkano::FileDescription::MakeDescriptionForFile(inArchiveName, file.Size());
+		AddFile(desc, file.Data());
 	}
 	
-	void ZipWriter::Close()
+	ZipWriter::~ZipWriter()
 	{
-		int centralDirsOffset = 0;
-		if (m_numFiles)
+		if (m_file)
 		{
-			centralDirsOffset = ftell(m_file);
-			fwrite(m_centralDirs.data(), m_centralDirs.size(), 1, m_file);
-			m_centralDirs.clear();
+			int centralDirsOffset = 0;
+			if (m_numFiles)
+			{
+				centralDirsOffset = ftell(m_file);
+				fwrite(m_centralDirs.data(), m_centralDirs.size(), 1, m_file);
+				m_centralDirs.clear();
+			}
+
+			EndOfCentralDirectoryHeader eocd;
+			eocd.centralDirectoryEntries = eocd.totalCentralDirectoryEntries = m_numFiles;
+			eocd.centralDirectoryOffset = centralDirsOffset;
+
+			fwrite(&eocd, sizeof(eocd), 1, m_file);
+			fclose(m_file);
 		}
-
-		EndOfCentralDirectoryHeader eocd;
-		eocd.centralDirectoryEntries = eocd.totalCentralDirectoryEntries = m_numFiles;
-		eocd.centralDirectoryOffset = centralDirsOffset;
-
-		fwrite(&eocd, sizeof(eocd), 1, m_file);
-		fclose(m_file);
 	}
 }
\ No newline at end of file
diff --git a/openVulkanoCpp/IO/Archive/ZipWriter.hpp b/openVulkanoCpp/IO/Archive/ZipWriter.hpp
index 7b25be8..0ae044c 100644
--- a/openVulkanoCpp/IO/Archive/ZipWriter.hpp
+++ b/openVulkanoCpp/IO/Archive/ZipWriter.hpp
@@ -21,9 +21,9 @@ namespace OpenVulkano
 
 	public:
 		ZipWriter(const std::filesystem::path& filePath);
+		~ZipWriter();
 
 		void AddFile(const FileDescription& description, const void* buffer);
 		void AddFile(const std::filesystem::path& fileName, const char* inArchiveName);
-		void Close();
 	};
 }
\ No newline at end of file