[pacman-dev] [PATCH] Kill compute_requiredby usage in deps.c/can_remove_package()

[Nagy Gabor]

> Comments inline.
> 
> On Sat, Apr 19, 2008 at 5:49 PM, Nagy Gabor <ngaba at bibl.u-szeged.hu>
> wrote:
> > >From 5b83eec6d87dc43a1f9dface9540220d8188edcf Mon Sep 17 00:00:00
> > >2001
> >  From: Nagy Gabor <ngaba at bibl.u-szeged.hu>
> >  Date: Sun, 20 Apr 2008 00:39:32 +0200
> >  Subject: [PATCH] Kill compute_requiredby usage in
> > deps.c/can_remove_package()
> >
> >  After this patch compute_requiredby is used nowhere in back-end,
> > so it can be optimized for front-end.
> >  * Before this patch the db param wasn't used, db == localdb was
> > supposed
> In reality, we would never do this on anything but the localdb,
> correct? Can we remove the param entirely?
> We really should go through the whole backend and stop passing
> pointers to the localdb around- I believe we have it always accessible
> on the handle. Of course, whether that is the best method is up for
> discussion too.

Correct. But in deps.c almost all functions have these pointers.

> 
> >  * This is a minor speed-up, since we needn't calculate the whole
> > requiredby list, if we find an ,,external'' member
> I have no idea what you mean by ,,external" member. Especially with
> the commas and unmatched quotes. Can you explain?
> 

Oops, ,,quote'' is the Hungarian "quote", sorry (in TeX style). External
refers to external member of requiredby list, which means package not
in 'targets' list. So we needn't calculate the whole requiredby list
(sometimes), we can stop if we find a package with that property.

> >
> >  Signed-off-by: Nagy Gabor <ngaba at bibl.u-szeged.hu>
> >  ---
> >   lib/libalpm/deps.c |   20 +++++++++++---------
> >   1 files changed, 11 insertions(+), 9 deletions(-)
> >
> >  diff --git a/lib/libalpm/deps.c b/lib/libalpm/deps.c
> >  index 1eebca3..4216e2c 100644
> >  --- a/lib/libalpm/deps.c
> >  +++ b/lib/libalpm/deps.c
> >  @@ -439,7 +439,7 @@ pmdepend_t *_alpm_dep_dup(const pmdepend_t
> > *dep) static int can_remove_package(pmdb_t *db, pmpkg_t *pkg,
> > alpm_list_t *targets, int include_explicit)
> >   {
> >  -       alpm_list_t *i, *requiredby;
> >  +       alpm_list_t *i, *j;
> >
> >         if(_alpm_pkg_find(alpm_pkg_get_name(pkg), targets)) {
> >                 return(0);
> >  @@ -461,15 +461,17 @@ static int can_remove_package(pmdb_t *db,
> > pmpkg_t *pkg, alpm_list_t *targets,
> >          * if checkdeps detected it would break something */
> >
> >         /* see if other packages need it */
> >  -       requiredby = alpm_pkg_compute_requiredby(pkg);
> >  -       for(i = requiredby; i; i = i->next) {
> >  -               pmpkg_t *reqpkg = _alpm_db_get_pkgfromcache(db,
> > i->data);
> >  -               if(reqpkg
> > && !_alpm_pkg_find(alpm_pkg_get_name(reqpkg), targets)) {
> >  -                       FREELIST(requiredby);
> >  -                       return(0);
> >  -               }
> >  +       for(i = _alpm_db_get_pkgcache(db); i; i = i->next) {
> >  +               pmpkg_t *lpkg = i->data;
> >  +               for(j = alpm_pkg_get_depends(lpkg); j; j =
> > j->next) {
> >  +                       if(alpm_depcmp(pkg, j->data)) {
> >  +                               if(!_alpm_pkg_find(lpkg->name,
> > targets)) {
> >  +                                       return(0);
> >  +                               }
> >  +                               break;
> >  +                       }
> >  +               }
> >         }
> >  -       FREELIST(requiredby);
> >
> >         /* it's ok to remove */
> >         return(1);
> >  --
> >  1.5.3.8
> 
> I like the patch though- the code changes are great and
> straightforward, so I'll pull this on a resubmit.
> 

What shall I change? The commit message?

Bye