Re: Question about your git habits

J.C. Pizarro
2008-02-23T13:08:55Z

On 2008/2/23, Charles Bailey <charles@hashpling.org> wrote:
> On Sat, Feb 23, 2008 at 03:47:07AM +0100, J.C. Pizarro wrote:
> >
> > Yesterday, i had git cloned git://foo.com/bar.git ( 777 MiB )
> > Today, i've git cloned git://foo.com/bar.git ( 779 MiB )
> >
> > Both repos are different binaries , and i used 777 MiB + 779 MiB = 1556 MiB
> > of bandwidth in two days. It's much!
> >
> > Why don't we implement "binary delta between old git repo and recent git repo"
> > with "SHA1 built git repo verifier"?
> >
> > Suppose the size cost of this binary delta is e.g. around 52 MiB instead of
> > 2 MiB due to numerous mismatching of binary parts, then the bandwidth
> > in two days will be 777 MiB + 52 MiB = 829 MiB instead of 1556 MiB.
> >
> > Unfortunately, this "binary delta of repos" is not implemented yet :|
>
>
> It sounds like what concerns you is the bandwith to git://foo.bar. If
> you are cloning the first repository to somewhere were the first
> clone is accessible and bandwidth between the clones is not an issue,
> then you should be able to use the --reference parameter to git clone
> to just fetch the missing ~2 MiB from foo.bar.
>
> A "binary delta of repos" should just be an 'incremental' pack file
> and the git protocol should support generating an appropriate one. I'm
> not quite sure what "not implemented yet" feature you are looking for.

But if the repos are aggressively repacked then the bit to bit differences
are not ~2 MiB.