Every time my function is getting called it is overwriting to the file. Kindly note I am opening file in unbuffered mode using below flags.
FILE_FLAG_NO_BUFFERING | FILE_FLAG_WRITE_THROUGH
If I am using simple buffered mode it is working fine.
FILE_ATTRIBUTE_NORMAL
I am getting following error in unbuffered mode.
** ERROR ** CreateFile failed: The parameter is incorrect.
Kindly find the code snippets below. This piece of code getting called many times.
HANDLE hFile;
LPCWSTR file_path = convertCharArrayToLPCWSTR(UNBUFFERED_FILE);
hFile = CreateFile(file_path,
FILE_APPEND_DATA,
FILE_SHARE_WRITE,
NULL,
OPEN_ALWAYS,
FILE_FLAG_NO_BUFFERING | FILE_FLAG_WRITE_THROUGH,
NULL
);
if (hFile == INVALID_HANDLE_VALUE)
{
std::cout << "Unable to open/create file for writing" << std::endl;
PrintError(TEXT("CreateFile failed"));
}
Data *data = new Data();
DWORD dwBytesToWrite = sizeof(Data);
DWORD dwBytesWritten = 0;
BOOL bErrorFlag = FALSE;
bErrorFlag = WriteFile(
hFile, // open file handle
data, // start of data to write
dwBytesToWrite, // number of bytes to write
&dwBytesWritten, // number of bytes that were written
NULL);
if (bErrorFlag == FALSE)
{
std::cout << "Unable to write to file" << std::endl;
PrintError(TEXT("Unable to write to file"));
}
if (dwBytesToWrite != dwBytesWritten)
{
std::cout << "Error in writing: Whole data not written" << std::endl;
PrintError(TEXT("Error in writing: Whole data not written"));
}
CloseHandle(hFile);
. Kindly suggest if any alternative idea is available.
from
NtCreateFile
so when you call
you use
FILE_FLAG_NO_BUFFERING
(mapped toFILE_NO_INTERMEDIATE_BUFFERING
) withFILE_APPEND_DATA
- you and must gotERROR_INVALID_PARAMETER
. you need remove one flag. i suggest removeFILE_FLAG_NO_BUFFERING
flag, because with it you can write only integral of the sector size.