文件映射相關操作(CreateFileMapping\MapViewOfFile)--TitanEngine

BOOL KtMapFileEx(const wchar_t* FileName, DWORD ReadOrWrite,
	LPHANDLE FileHandle, LPDWORD FileSize,
	LPHANDLE FileMap, LPVOID FileMapVA,
	DWORD SizeModifier)
{
	DWORD FileAccess = 0;
	DWORD FileMapType = 0;
	DWORD FileMapViewType = 0;

	if (ReadOrWrite == UE_ACCESS_READ)
	{
		FileAccess = GENERIC_READ;
		FileMapType = PAGE_READONLY;
		FileMapViewType = FILE_MAP_READ;
	}
	else if (ReadOrWrite == UE_ACCESS_WRITE)
	{
		FileAccess = GENERIC_WRITE;
		FileMapType = PAGE_READWRITE;
		FileMapViewType = FILE_MAP_WRITE;
	}
	else if (ReadOrWrite == UE_ACCESS_ALL)
	{
		FileAccess = GENERIC_READ + GENERIC_WRITE + GENERIC_EXECUTE;
		FileMapType = PAGE_EXECUTE_READWRITE;
		FileMapViewType = FILE_MAP_WRITE;
	}
	else
	{
		FileAccess = GENERIC_READ + GENERIC_WRITE + GENERIC_EXECUTE;
		FileMapType = PAGE_EXECUTE_READWRITE;
		FileMapViewType = FILE_MAP_ALL_ACCESS;
	}

	HANDLE v1 = CreateFileW(FileName,
		FileAccess,
		FILE_SHARE_READ,
		NULL,
		OPEN_EXISTING,
		FILE_ATTRIBUTE_NORMAL,
		NULL);
	if (v1 != INVALID_HANDLE_VALUE)
	{
		*FileHandle = v1;
		DWORD v7 = GetFileSize(v1, NULL);
		v7 = v7 + SizeModifier;
		*FileSize = v7;
		HANDLE v5 = CreateFileMapping(v1,
			NULL,
			FileMapType,
			NULL,
			v7,
			NULL);
		if (v5 != NULL)
		{
			*FileMap = v5;
			LPVOID v10 = MapViewOfFile(v5, FileMapViewType, NULL, NULL, NULL);
			/*
			v10 = 0x003b0000
			0x003B0000  4d 5a 90 00 03 00 00 00 04 00 00 00 ff ff  MZ?...........
			0x003B000E  00 00 b8 00 00 00 00 00 00 00 40 00 00 00  ..?.......@...
			0x003B001C  00 00 00 00 00 00 00 00 00 00 00 00 00 00  ..............
			0x003B002A  00 00 00 00 00 00 00 00 00 00 00 00 00 00  ..............
			0x003B0038  00 00 00 00 d0 00 00 00 0e 1f ba 0e 00 b4  ....?.....?..?
			0x003B0046  09 cd 21 b8 01 4c cd 21 54 68 69 73 20 70  .?!?.L?!This p
			0x003B0054  72 6f 67 72 61 6d 20 63 61 6e 6e 6f 74 20  rogram cannot
			0x003B0062  62 65 20 72 75 6e 20 69 6e 20 44 4f 53 20  be run in DOS
			0x003B0070  6d 6f 64 65 2e 0d 0d 0a 24 00 00 00 00 00  mode....$.....
			*/
			if (v10 != NULL)//v10是映射出來的地址
			{
				//將v10所指向的地址值放入FileMapVA中
				RtlMoveMemory(FileMapVA, &v10, sizeof ULONG_PTR);
				return true;
			}
		}
		RtlZeroMemory(FileMapVA, sizeof ULONG_PTR);
		*FileHandle = NULL;
		*FileSize = NULL;
		KtCloseHandle(v1);
	}
	else
	{
		RtlZeroMemory(FileMapVA, sizeof ULONG_PTR);
	}
	return false;
}

VOID KtUnMapFileEx(HANDLE FileHandle, DWORD FileSize, HANDLE FileMap, ULONG_PTR FileMapVA)
{
	if (UnmapViewOfFile((void*)FileMapVA))
	{
		KtCloseHandle(FileMap);
		SetFilePointer(FileHandle, FileSize, NULL, FILE_BEGIN);
		SetEndOfFile(FileHandle);
		KtCloseHandle(FileHandle);
	}
}