Hi Hedayat, check out the link, pointing to my repo, posted by Ales (https://github.com/Tojaj/DeltaRepo) and feel free to ask any question if you have some.
Tomas ----- Original Message ----- > (Forwarded to yum-devel list since it is being held for moderation) > > > -------- Original Message -------- > Subject: A proposal to create a kind of 'delta metadata' (for XML md for > now) > Date: Wed, 30 Jul 2014 01:15:15 +0430 > From: Hedayat Vatankhah <heday...@gmail.com> > To: rpm-metad...@lists.baseurl.org > > Dear all, > While I'm thinking about a completely new repository format, but I found that > would need much time from my side and probably lots of discussions. But I > think that implementing a kind of delta metadata support for the current > format is much easier and possibly provides considerable improvement for > updates compared to the current situation where a completely new metadata is > generated for updates. And I think I can contribute code too. > > Anyway, I'd like to propose my idea and request for feedback. My suggestion > is currently limited to XML MD format only, which is more space efficient > than SQLite dbs in itself. And specially since DNF is using them. > > The idea is very simple: when createrepo is going to update an existing > repodata, it doesn't replace the old primary/filelists/etc data. Instead, it > creates new xml files containing data about added/modified/deleted packages > (a deleted package can be marked by having an entry for it without any data > except its name and EVR. A special attribute might be added if needed). And, > repomd.xml contains reference to these new files only. > > Now, how older metadata files are referenced? They are referenced from the > new MD files, just like how repomd.xml refers to the latest versions. For > example, new primary.xml file which contains data about latest > added/modified/deleted packages references the previous primary.xml file > (which in turn might reference an older primary.xml database). Therefore, we > have a linked list of primary.xml files, where the head is the latest > primary delta and the tail is the main primary.xml file created when the > repo was created. > > I like the idea of linked lists here, because it is scalable! But if it seems > overkill (does not allow pipelining to download a number of delta xml files, > because you should download an open an XML file to learn about the name of > previous one), we might come up with some other suggestions for storing the > list, e.g. the list might be stored in repomd.xml itself, or a separate file > for interested clients. > > IMHO, this can be easily implemented in createrepo, and should be fairly > straightforward for clients to use. What do you think? > > Regards, > Hedayat > > > > _______________________________________________ > Yum-devel mailing list > Yum-devel@lists.baseurl.org > http://lists.baseurl.org/mailman/listinfo/yum-devel > -- Tomas Mlcoch (irc: tmlcoch) Release Configuration Management Brno, Czech Republic _______________________________________________ Yum-devel mailing list Yum-devel@lists.baseurl.org http://lists.baseurl.org/mailman/listinfo/yum-devel
