Jakub Narebski <jnareb@xxxxxxxxx> wrote: > Johannes Schindelin <Johannes.Schindelin@xxxxxx> writes: > > On Mon, 14 Jul 2008, Shawn O. Pearce wrote: > > > > The only other alternative I can come up with is to change pack-objects > > > (or at least its defaults) so we don't generate these massive delta > > > chains. But there are already packs in the wild that use these chains, > > > resulting in performance problems for clients. > > > > But the long chains make the pack actually as efficient as it is... > > Perhaps Shawn thought here about limiting delta chain not by its > *length*, but by its *size* (as required when unpacking last object > in a delta chanin). > > What do you think about this idea? I was talking about that. Or at least thinking it. But its not a good solution, as Dscho points out those long chains is what makes the pack file such a powerful source code compressor. IMHO the right solution is to continue to allow these long chains, especially since they are typically used for the older, less often accessed objects, and use bounded caching where necessary in the readers to avoid unpacking costs. We already have a bounded cache for the random access case used by most programs. What we missed was the bounded cache in index-pack, and my 4 patch series is an attempt to define that. -- Shawn. -- 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
