create local utility function for IoBufferBuilder::MakeFromFile*

1 files changed, 25 insertions, 48 deletions

diff --git a/zencore/iobuffer.cpp b/zencore/iobuffer.cpp
index 61db25d0f..b948493a7 100644
--- a/zencore/iobuffer.cpp
+++ b/zencore/iobuffer.cpp
@@ -469,60 +469,20 @@ IoBufferBuilder::MakeFromFileHandle(void* FileHandle, uint64_t Offset, uint64_t
 	return IoBuffer(IoBuffer::BorrowedFile, FileHandle, Offset, Size);
 }
 
-IoBuffer
-IoBufferBuilder::MakeFromFileWithSharedDelete(const std::filesystem::path& FileName)
+static IoBuffer
+MakeFromFileWithOptions(const std::filesystem::path& FileName, uint64_t Offset, uint64_t Size, bool UseShareDelete)
 {
-	uint64_t Size;
+	uint64_t FileSize;
 
 #if ZEN_PLATFORM_WINDOWS
 	CAtlFile DataFile;
 
-	HRESULT hRes = DataFile.Create(FileName.c_str(), GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_DELETE, OPEN_EXISTING);
-
-	if (FAILED(hRes))
-	{
-		return {};
-	}
-
-	DataFile.GetSize((ULONGLONG&)Size);
-#else
-	int Fd = open(FileName.c_str(), O_RDONLY | O_CLOEXEC);
-	if (Fd < 0)
+	DWORD ShareOptions = FILE_SHARE_READ;
+	if (UseShareDelete)
 	{
-		return {};
+		ShareOptions |= FILE_SHARE_DELETE;
 	}
-
-	static_assert(sizeof(decltype(stat::st_size)) == sizeof(uint64_t), "fstat() doesn't support large files");
-	struct stat Stat;
-	fstat(Fd, &Stat);
-	Size   = Stat.st_size;
-#endif	// ZEN_PLATFORM_WINDOWS
-
-	if (Size)
-	{
-#if ZEN_PLATFORM_WINDOWS
-		void* Fd = DataFile.Detach();
-#endif
-		return IoBuffer(IoBuffer::File, (void*)uintptr_t(Fd), 0, Size);
-	}
-
-#if !ZEN_PLATFORM_WINDOWS
-	close(Fd);
-#endif
-
-	// For an empty file, we may as well just return an empty memory IoBuffer
-	return IoBuffer(IoBuffer::Wrap, "", 0);
-}
-
-IoBuffer
-IoBufferBuilder::MakeFromFile(const std::filesystem::path& FileName, uint64_t Offset, uint64_t Size)
-{
-	uint64_t FileSize;
-
-#if ZEN_PLATFORM_WINDOWS
-	CAtlFile DataFile;
-
-	HRESULT hRes = DataFile.Create(FileName.c_str(), GENERIC_READ, FILE_SHARE_READ, OPEN_EXISTING);
+	HRESULT hRes = DataFile.Create(FileName.c_str(), GENERIC_READ, FILE_SHARE_READ | ShareOptions, OPEN_EXISTING);
 
 	if (FAILED(hRes))
 	{
@@ -531,7 +491,12 @@ IoBufferBuilder::MakeFromFile(const std::filesystem::path& FileName, uint64_t Of
 
 	DataFile.GetSize((ULONGLONG&)FileSize);
 #else
-	int Fd = open(FileName.c_str(), O_RDONLY);
+	int Flags = O_RDONLY;
+	if (UseShareDelete)
+	{
+		Flags |= O_CLOEXEC;
+	}
+	int Fd = open(FileName.c_str(), Flags);
 	if (Fd < 0)
 	{
 		return {};
@@ -575,6 +540,18 @@ IoBufferBuilder::MakeFromFile(const std::filesystem::path& FileName, uint64_t Of
 }
 
 IoBuffer
+IoBufferBuilder::MakeFromFileWithSharedDelete(const std::filesystem::path& FileName)
+{
+	return MakeFromFileWithOptions(FileName, ~0ull, 0, true);
+}
+
+IoBuffer
+IoBufferBuilder::MakeFromFile(const std::filesystem::path& FileName, uint64_t Offset, uint64_t Size)
+{
+	return MakeFromFileWithOptions(FileName, Offset, Size, false);
+}
+
+IoBuffer
 IoBufferBuilder::MakeFromTemporaryFile(const std::filesystem::path& FileName)
 {
 	uint64_t FileSize;