On Thu, 6 Sep 2007, Junio C Hamano wrote: > Nicolas Pitre <nico@xxxxxxx> writes: > > > I wonder if this is the best way to go. In the context of a really fast > > repack happening automatically after (or during) user interactive > > operations, the above seems a bit heavyweight and slow to me. > > Honestly, I do not believe in that mode of operation that much. > > "While the user is waiting for the EDITOR"? > > Because you do not know how much time you will be given before > you start, unless > > (1) your process can be snapshotted and you can restart at the > next chance; or > > (2) it is so cheap and you can afford to abort and start over > from scratch at the next chance; or > > (3) it is so quick that you can simply have the user wait until > you are done without adding too much latency to be annoying, > when you cannnot finish before the EDITOR come back; I think we have to aim for #3. "Automatic" certainly doesn't imply "can be slow". It should be reasonably instantaneous, otherwise it'll become annoying quickly enough. If it can't be (almost) instantaneous in 99% of normal cases, then I think it simply should be remain asynchronously througha manual invokation of 'git gc' and we only need to teach/remind people about it more strongly. > >> An obvious next steps that can be done in parallel by interested > >> parties would be: > >> > >> (1) come up with a way to give "name" aka "clustering cue" (I > >> think this is very hard); > > > > It is, and IMHO not worth it. If you do it separately from the usual > > pack-objects process you'll perform extra IO and decompression when > > walking tree objects just to reconstruct those paths, becoming really > > slow by the context definition I provided above. > > Well, I said "name" in quotes because you do _NOT_ have to give > the real name. I was not thinking about doing the actual tree > traversal at all. What you need to do is to come up with a > token that is the same for the objects in the same deltification > chain so that they cluster together, and that should be doable > by looking at the delta chain patterns inside a packfile. Obviously! Sorry for being slow. But I still think that a single repack pass should already be able to pick loose objects and selected (small) packs, and produce a pack with them all. No need for a separate merge-pack I'd say. Nicolas - To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
