Am Dienstag, den 15.03.2005, 15:49 -0300 schrieb Alexandre Oliva: > On Mar 14, 2005, Joe Desbonnet <jdesbonnet@xxxxxxxxx> wrote: > > > Indeed there are serveral approaches to this problem, all with their > > upsides and downsides. I'm currently treating the cpio archive as one > > big file, and you're probably right -- treating it a file system may > > yield better results. > > I doubt it. In several cases, files get packaged in different > directories or have names changed because of a version change, and > then per-file deltas or rsync of individual files won't save you > anything, but rsync of the entire archive will be able to pick up the > unchanging bits. But I don't think that changing names/paths occur that often (I may be wrong here, but I doubt it). This could be tested out easily and a final version might either decide wich of the two methods (single file or multiple ones) to use on a per rpm basis or try to find the new name or new location of the file. But that is the future, a simple implementation would come first. The other argument against using the whole rpm would be resources: memory consumption is O(n) according to Joe's nice page with the test results. And time is O((n+m) log n) according to the bsdiff site. And having big packages like OOo or kernel reducing the input-file-size would do a great job in reducing needed resources. While I need say that I also see the problem of having to strip a nice packaged rpm apart before doing the diff involves some more code in to get the job done. Which in turn involves more errors. Thomas
