Reading Large Binary File

[dominicanjb]

I'm trying to read a large (~1.3 Gig) binary file, but I get stuck allocating memory to the buffer. Here is a fragment of the code:

	//Initialize error_code
	error_code = 0;

	//Get the file size
	DWORD dwBSize = MyFileOps.get_file_size(ThisFile);

	//Check for minimimum file size
	if(dwBSize < MIN_RAW_SIZE) {error_code = -1; return 0;}

	//Declare the buffer that will hold the raw file info
	unsigned char *rBuffer = NULL;

	//Allocate memory to rBuffer
	rBuffer = new (nothrow) unsigned char[dwBSize];
	if(NULL == rBuffer) {error_code = -2; return 0;}

	//Load the file into memory
	if(!MyFileOps.load_file(ThisFile, rBuffer, dwBSize))
	{
		delete [] rBuffer; rBuffer = NULL;
		error_code = -3;
		return 0;
	}

The program returns with error_code = -2; meaning it could not allocate memory to the buffer. I made a class that is associated with all file transactions; such as determining the file size using "GetFileSize", reading the file using "ReadFile." The code above is for a GUI interface with classes. I re-wrote the program with a traditional DOS interface using the same WIN API functions, but without a class and was able to read the file (although it took some time). Any help is greatly appreciated.

Thanks,

DominicanJB

[Austin J]

I could be wrong, but I don't think there's really any way to allocate that much memory in one block, there's only so much you can keep on one contiguous section.

[tath]

if you have huge file, copying it to memory is rather silly solution. You need to use memory mapping.
Info:
https://msdn.microsoft.com/en-us/library/dd997372%28v=vs.110%29.aspx
https://msdn.microsoft.com/en-us/library/ms810613.aspx
http://www.catch22.net/tuts/memory-techniques-part-1