From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Reiser Subject: Re: repost for readdir Date: Thu, 24 Jun 2004 11:27:59 -0700 Message-ID: <40DB1D2F.4010303@namesys.com> References: <1088032186.12051.8.camel@murdock.llnl.gov> <40DB0D73.3070605@namesys.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <40DB0D73.3070605@namesys.com> List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: "Vladimir V. Saveliev" Cc: jenn sirp , reiserfs-list@namesys.com Vladimir V. Saveliev wrote: > Hello > > jenn sirp wrote: > >> Hi, >> >> I'd like to thank you guys for your help earlier this year with the >> initial phase of my project. I was able to implement FIFO queueing >> functionality in Reiser v3. It is not very elegant, but I am still >> learning. I was able to steer my supervisor in the direction of Reiser4. >> It appears that the design principles of the new system will make it >> very >> valuable for many at the Lab. >> >> That said, and back to Hans' suggestion of a readdir implementation for >> FIFO and LIFO file queuing... I have some questions. If anyone can >> answer >> them, has advice, or suggestions that would be so great. >> >> Here's where I am at, and what I don't know: >> >>> From what I can tell, files in the reiserfs 'Directory Item' aren't >>> preserved in >> >> the order they are written due to deletes and other operations. So if I >> were to access the Directory Item to generate a list for readdir I >> couldn't be certain that they would be in first >> created -to- last created order. > We sort in hash order, not creation order. >> >> If readdir has to sort the files in the directory every time it is >> called >> it seems like it would be a bit of a performance hit. > > > Do you mean readdir library function? It reads directory and fills > dirent structures. It does not sort anything. It even does not stat > files names of which it reads. > > Should another > >> structure be maintained that preserves the order as the files are >> written... and should readdir use that as it's basis for returning the >> directory contents? >> > > Are you trying to optimize ls -l? > > Please describe in more details what are you trying to do. > >> If this is a question that doesn't belong here... please let me know >> and I apologize. >> >> Thanks, >> >> Jenn >> >> >> > > > > Please consider working with V4, it will be easier and more useful I think.