On 2015-04-27 09:44:09 +0200, Vincent Lefevre wrote: > On 2015-04-24 21:41:41 -0500, David Wright wrote: > > Quoting Vincent Lefevre (vinc...@vinc17.net): > > > This is now done in my script, but I had to use the ReadDir module > > > from CPAN, since both readdir implementations in Perl (the standard > > > readdir Perl function and POSIX::readdir) just return the file name. > > > And this ReadDir module isn't available in a Debian package. > > > > Python's library function listdir suffers the same way. If you want > > the inode, you have to call stat to get it. (I haven't looked for > > external modules like ReadDir as I don't have very large directories.) > > I haven't tried, but I don't think that a stat call would solve the > problem: most stat information isn't in the directory entries, thus > it will have to be loaded from disk in some arbitrary order, just > like if the first block of a file were read (which is precisely what > I want to avoid at this moment).
I've just done a test in my Perl script, and actually, using stat in the directory order is actually very fast on ext3, so that it would solve the problem. I think that the reason is that inode information is grouped at some specific place on the partition (as someone said in another message), and in a compact way I assume, so that there are few blocks to read, which is not the case when reading one line of each file (= one block of each file). However I think that using the ReadDir module (which provides the inode with needing a stat call) guarantees more efficiency, though this may not be noticeable in most cases. -- Vincent Lefèvre <vinc...@vinc17.net> - Web: <https://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon) -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/20150428144621.ga3...@ypig.lip.ens-lyon.fr
