On Jun 6 11:31, Corinna Vinschen wrote: > On Jun 2 18:32, Brian Dessent wrote: > > In order to implement stat(), cygwin has to call NtQueryInformationFile > > (GetFileInformationByHandle for 9x/me) and this requires the file to be > > opened. Thus the reason that stat takes forever is that each file has > > There would be a theoretical way around this. NtQueryDirectoryFile allows > to get all information about a file (with a prominent exception) without > having to open the file. Instead you just need the handle to the parent > directory. We don't have the infrastructure in Cygwin right now to use > this method easily, but it could speed up stat when, for instance, the file > is in the current working directory or if the process has called opendir on > the parent directory of the file.
Further testing of the NtQueryDirectoryFile function shows that it's not usable as I imagined. If you want to retrieve information about a single file without disturbing the current opendir/readdir, it's necessary to open the directory again. The directory handle used in the current opendir/readdir is not usable for this purpose. Neither is a duplicated handle of it. Oh boy. Looks like the only useful way to use it is caching the results. As far as that's useful. Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Project Co-Leader mailto:cygwin@cygwin.com Red Hat, Inc. -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
