Re: [gentoo-portage-dev] [PATCH] postsync: skip hooks and metadata-transfer when appropriate (bug 564988)

[Michał Górny]

On Fri, 6 Nov 2015 10:58:23 -0800
Zac Medico <zmedico@g.o> wrote:

> On 11/06/2015 10:39 AM, Michał Górny wrote:
> > On Fri, 6 Nov 2015 09:24:15 -0800
> > Zac Medico <zmedico@g.o> wrote:
> >
> >> On 11/06/2015 12:20 AM, Alexander Berntsen wrote:
> >>> On 06/11/15 09:05, Michał Górny wrote:
> >>>>>> I know nothing about the egencache stuff. Maybe Michał can
> >>>>>> comment?
> >>>> Michał finds this black magic. Trusts zmedico.
> >>> I think it looks like it's probably supposed to be reasonable, perhaps.
> >>>
> >>> Maybe Brian can look at it. At least that way we'll have a lot of
> >>> people that attempted understanding what's going on.
> >>>
> >>> Maybe we need a "Trusted-by:" line.
> >>>
> >>
> >> Maybe it helps if I give some more context. At my workplace, we have
> >> lots of scripts that call `emerge --sync private-work-repo` to ensure
> >> that the current system has the latest changes from private-work-repo.
> >> It can be annoying if it spends the bulk of its time calling hooks, even
> >> though private-work-repo was already up-to-date:
> >>
> >>>>> Timestamps on the server and in the local repository are the same.
> >>>>> Cancelling all further sync action. You are already up to date.
> >>
> >> So, we want to skip the hooks when repos are already up-to-date. In this
> >> case, there's no point in calling hooks or updating the metadata cache.
> >
> > This is incorrect assumption. A change in master repo may trigger
> > metadata cache update in slaved repo.
> >
>
> Good point. I'll update it to account for this.

Please don't. This is just one of the corner cases when it will fail.
You can't assume any post-sync hook can be skipped if X or Y didn't
change.

-- 
Best regards,
Michał Górny
<http://dev.gentoo.org/~mgorny/>