[pacman-dev] Move -Sw to front-end

[Nagy Gabor]

> > 2. First I thought something like this:
> > alpm_download_packages(alpm_list_t *packages, ...)
> > This seems the easiest to implement (cut from sync_commit).
> > However, if we want transaction-independent function, we should do
> > pmsyncpkg_t -> pmpkg_t conversion always. (Ugly)
> > 3. Then I started to like the following:
> > alpm_download_package(pmpkg_t *package)
> > We have a problem with this, in this case if we want to keep the
> > current "download all packages then check all integrity" order we
> > should make something like alpm_check_integrity public (no, too
> > complicated). Alternatively, we could check_integrity in
> > download_package. This is also logical, but changes the current
> > behaviour (order).
> >
> 
> I don't understand why you need to do ugly conversions for 2 but not
> for 3.

2. you have to build/free a new list
3. you can call on "spkg->pkg" for each sync package
This is not much difference, indeed.

Btw, almost all alpm functions require pmpkg_t*, resolvedeps,
checkdeps, checkconflicts... So "build/free a new list" is already done
in many places.

> I am definitely not proud of this hardwired sync_prepare computing.
> About on-demand access, is that possible?
> As you said, these two fields depend on the filecache. How do you
> detect that the filecache has changed?

I assume that filecache is modified via alpm. (This is partly true,
because -Sc is implemented in the front-end!) This is closer to reality
than the current hardwired stuff.

> So even if you have some on-demand access to both fields, I believe
> you still need to update them each time the filecache is affected.
> Maybe this is doable if each functions causing write to the filecache
> also update these two fields. So maybe a download(pkg) function could
> handle that?

Yes I thought that download function should handle that. I thought
about a very primitive delta_path handling as a starting point. (If all
delta downloads were successful, clear delta_path, if one of them was
unsuccessful, set delta_path (and download_size) to "not computed")

> And I guess that function should take care of delta too : if an old
> package is present in filecache, then compute delta path, download
> delta files, and apply them. Otherwise just download the package?
> 
> > I may mixed many things here, and I may misunderstand something
> > (this delta stuff made things quite complicated in sync.c)
> >
> I agree, this complicates things quite a lot for no benefit (at least
> for now).

And it is difficult to test them...

I still don't know what to do;-)
I even don't know whether you support the primary "goal": cleaner
trans_commit.

Bye