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Hi
What is the fastest way to retrieve the (64 bit) filesize of a file?
I need to get the size of *many* files from various locations (on WinXP systems,only), so what would be faster:
CreateFile + GetFileSize + CloseHandle
or
FindFirstFile / FindNextFile
or do you have another idea?
Thank you in advance.
Oliver.
hi,
FindFirstFile/FindNextFile/FindClose seems to be the fastest and
preferred ...IMHO
Praseed Pai
Although I haven't used any of them so far, but they look handy for this purpose.
GetFileSize
GetCompressedFileSize
GetFileSizeEx
You can also try GetFileAttributesEx ().
I'm not sure whether it is faster than FindFirst/FindNext/FindClose, but it is definitely faster than CreateFile/GetFileSize (which also modifies the file last access time).
Thank you for your suggestions!
@Ejaz
But GetFileSize etc. require that the file was previously opened by a call to CreateFile. This is the API I'm currently using, but it seems a little slow to me.
@genossa
Bingo! I knew there was a function which takes the file path and returns the 64bit file size, but I could not remember what it was. I believe this will be much faster, so I'll try it next week and post the results of my little test :)
Thank you all & have a good weekend.
Oliver.
I use _stat64 which accepts a filename and which retrieves a 64 bit size.
I just tried GetFileAttributesEx(...) and it really seems to be *much* faster than GetFileSize(...)!
The only drawback is that GetFileAttributesEx(...) is not supported by Win95.
@Marc G
Thank you; I didn't knew this C runtime function (_stati64, _wstati64). I'll give them a try and report back!
Oliver.
At least on my Win2k workstation, _stati64 is screaming fast compared to CreateFile / GetFileSize / CloseFile!Quote:
Originally Posted by Marc G
Maybe it is a drawback that it does not support security attributes, but I do not need that anyway.
Thank you for this tip!
Oliver.
One more tip:
_stat64 uses FindFirstFile/FindClose inside (just looked into the source code of
_stat64 for Visual Studio). So, if your application is designed for Windows paltform then using FindFirstFile/FindClose directly will be a little bit faster than calling to _stat64 :)
Hi genossa
Where did you look it up? I just searched the MS VC directory and the web but did not find the implementation of stati64.
BTW: The function names are _stati64 and _wstati64().
Oliver.
Oh, I just found it: VC98\CRT\SRC\STAT.C function declaration "int __cdecl _tstati64".
It really uses FindFirstFile / FindClose API. I must say that I did not believe these APIs are that fast!
Thank you.
Oliver.
Hi ,
on my machine i have installed VS.net in the C folder.
u may find the source code of the routines mentioned above in the following path
C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\crt\src
Praseed Pai
www.praseedpai.com
Oops. My bad. :)Quote:
BTW: The function names are _stati64 and _wstati64().