Reading large mapped text file in C++ - c++

Question

I am attempting to display a large amount of text(barely less than 1GB).
My code:
HANDLE hFile;
DWORD dwBytesRead = 0;
OVERLAPPED ol = {0};
HANDLE m_hMapFile;
hFile = CreateFile(_T("test.txt"),
GENERIC_WRITE | GENERIC_READ,
0,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED,
NULL);
m_hMapFile = CreateFileMapping(hFile, NULL, PAGE_READWRITE, 0, 0, NULL);
LPVOID m_lpMapAddress = MapViewOfFile(m_hMapFile, FILE_MAP_ALL_ACCESS, 0,
0, 0);
}
Now that the text file is mapped, how do I display its contents? I have attempted the following (poor) implementation:
char *mappedData = (char*)m_lpMapAddress;
for(int k = 0; k < strlen(mappedData); k++){
cout<<mappedData [k];
}
This is obviously not the right way to display the text contents. Is there a more efficient method?

Answer 1

You may try doing all your output at once:
cout.write(mappedData, mappedSize);
But note that printing a gigabyte of data to console is not likely to be efficient anyhow.
Console output has purpose of being read by user (programmatic parsing is secondary thing). Do you expect user to read 1 GB of data?