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fast file count method?Is there some way to determine file count on a drive? I know I can use
System.IO.DriveInfo and My.Computer.FileSystem.GetFiles to obtain a file count, but this approach is pretty slow -- is there a faster more efficient method available? ..NET 2.0 framework is my base. thanks, Rob. the managed way is :
System.IO.DirectoryInfo dinfo = new System.IO.DirectoryInfo("c:\\windows"); int filecount = dinfo.GetFiles().Length; otherwise you need to PInvoke C++ function from Win API. HTH Show quote "Rob R. Ainscough" wrote: > Is there some way to determine file count on a drive? I know I can use > System.IO.DriveInfo and My.Computer.FileSystem.GetFiles to obtain a file > count, but this approach is pretty slow -- is there a faster more efficient > method available? > > ..NET 2.0 framework is my base. > > thanks, Rob. > > > "Luca Beretta" <LucaBere***@discussions.microsoft.com> wrote in message .... which will be just as slow as the method the OP suggested.news:C834CC43-5653-45F3-AC92-C08A7A46C672@microsoft.com... > the managed way is : > > System.IO.DirectoryInfo dinfo = new > System.IO.DirectoryInfo("c:\\windows"); > int filecount = dinfo.GetFiles().Length; > > otherwise you need to PInvoke C++ function from Win API. In short, no - there's no faster way to get a full count of files than by counting them. Exactly how you go about counting them is a matter of some debate, but they'll all boil down to calls to FindFirstFile/FindNextFile at the Win32 level and so will all take about the same amount of time. You can use the class described in this article: http://www.codeproject.com/cs/files/FileSystemEnumerator.asp to count files as well - it will take the same amount of time as the methods described above, but it won't take as much memory since it doesn't return a string[] of file names. -cd There has to be a more efficient approach? Especially since windows index
services are running on most PCs. Is the OS really that handicapped such that it doesn't keep a pointer count? Show quote "Carl Daniel [VC++ MVP]" <cpdaniel_remove_this_and_nospam@mvps.org.nospam> wrote in message news:eECZ$hYlGHA.5044@TK2MSFTNGP02.phx.gbl... > "Luca Beretta" <LucaBere***@discussions.microsoft.com> wrote in message > news:C834CC43-5653-45F3-AC92-C08A7A46C672@microsoft.com... >> the managed way is : >> >> System.IO.DirectoryInfo dinfo = new >> System.IO.DirectoryInfo("c:\\windows"); >> int filecount = dinfo.GetFiles().Length; >> >> otherwise you need to PInvoke C++ function from Win API. > > ... which will be just as slow as the method the OP suggested. > > In short, no - there's no faster way to get a full count of files than by > counting them. Exactly how you go about counting them is a matter of some > debate, but they'll all boil down to calls to FindFirstFile/FindNextFile > at the Win32 level and so will all take about the same amount of time. > > You can use the class described in this article: > > http://www.codeproject.com/cs/files/FileSystemEnumerator.asp > > to count files as well - it will take the same amount of time as the > methods described above, but it won't take as much memory since it doesn't > return a string[] of file names. > > -cd > > Rob R. Ainscough wrote:
> There has to be a more efficient approach? Especially since windows index number of files on a disk, rather than just the number within a> services are running on most PCs. Is the OS really that handicapped such > that it doesn't keep a pointer count? > >From some of what you posted, I gather you're trying to count the particular directory? If this is the case, then go into the root of your system drive, highlight everything, and bring up the properties. Notice how the count of files is goes up, as the system traverses all of the directories and does file counts? If something as simple as the properties page is having to do this work, it pretty much indicates to me that there isn't a faster method available in Windows, or they'd have done it there already. Damien Rob R. Ainscough wrote:
> There has to be a more efficient approach? Especially since windows I don't know if I'd call it handicapped, but yes - there's no documented > index services are running on most PCs. Is the OS really that > handicapped such that it doesn't keep a pointer count? better way. The total file count simply isn't kept by the file system. In the metadata of NTFS there are counts of useful things (useful to the filesystem) like the MFT size, and the number of used MFT records, but the total file count is apparently not useful enough to be worth the effort of maintaining it. I suspect that a low-level scan of the MFT to count file records would be more efficient, but there's no documented APIs for doing that. -cd  |
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