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

[Dan McGee]

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.

>  * 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?

>
>  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.

-Dan