added BasicFile::FlushDataOnly

2 files changed, 39 insertions, 0 deletions

diff --git a/src/zenutil/basicfile.cpp b/src/zenutil/basicfile.cpp
index 7d0edaa5d..7f1712d2b 100644
--- a/src/zenutil/basicfile.cpp
+++ b/src/zenutil/basicfile.cpp
@@ -11,6 +11,27 @@
 
 #if ZEN_PLATFORM_WINDOWS
 #	include <zencore/windows.h>
+extern "C"
+{
+#	define STATUS_SUCCESS ((NTSTATUS)0x00000000L)	// ntsubauth
+#	define NTAPI __stdcall
+
+	typedef DWORD NTSTATUS;
+
+	typedef struct _IO_STATUS_BLOCK
+	{
+		union
+		{
+			NTSTATUS Status;
+			PVOID	 Pointer;
+		} DUMMYUNIONNAME;
+
+		ULONG_PTR Information;
+	} IO_STATUS_BLOCK, *PIO_STATUS_BLOCK;
+
+	NTSTATUS NTAPI
+	NtFlushBuffersFileEx(HANDLE FileHandle, ULONG Flags, PVOID Parameters, ULONG ParametersSize, PIO_STATUS_BLOCK IoStatusBlock);
+}
 #else
 #	include <fcntl.h>
 #	include <sys/file.h>
@@ -345,6 +366,23 @@ BasicFile::Flush()
 #endif
 }
 
+void
+BasicFile::FlushDataOnly()
+{
+#if ZEN_PLATFORM_WINDOWS
+	IO_STATUS_BLOCK Iosb{};
+	NTSTATUS		Status = NtFlushBuffersFileEx(m_FileHandle, FLUSH_FLAGS_FILE_DATA_ONLY, nullptr, 0, &Iosb);
+
+	if (Status != STATUS_SUCCESS)
+	{
+		// warn?
+	}
+#else
+	int Fd = int(uintptr_t(m_FileHandle));
+	fdatasync(Fd);
+#endif
+}
+
 uint64_t
 BasicFile::FileSize()
 {
diff --git a/src/zenutil/include/zenutil/basicfile.h b/src/zenutil/include/zenutil/basicfile.h
index f25d9f23c..42cea904a 100644
--- a/src/zenutil/include/zenutil/basicfile.h
+++ b/src/zenutil/include/zenutil/basicfile.h
@@ -60,6 +60,7 @@ public:
 	void	 Write(const void* Data, uint64_t Size, uint64_t FileOffset);
 	void	 Write(const void* Data, uint64_t Size, uint64_t FileOffset, std::error_code& Ec);
 	void	 Flush();
+	void	 FlushDataOnly();
 	[[nodiscard]] uint64_t FileSize();
 	[[nodiscard]] uint64_t FileSize(std::error_code& Ec);
 	void				   SetFileSize(uint64_t FileSize);