Linux Archive

Linux Archive (http://www.linux-archive.org/)
-   ArchLinux Pacman Development (http://www.linux-archive.org/archlinux-pacman-development/)
-   -   Kill compute_requiredby usage in deps.c/can_remove_package() (http://www.linux-archive.org/archlinux-pacman-development/73318-kill-compute_requiredby-usage-deps-c-can_remove_package.html)

"Dan McGee" 04-21-2008 12:22 AM

Kill compute_requiredby usage in deps.c/can_remove_package()
 
Comments inline.

On Sat, Apr 19, 2008 at 5:49 PM, Nagy Gabor <ngaba@bibl.u-szeged.hu> wrote:
> >From 5b83eec6d87dc43a1f9dface9540220d8188edcf Mon Sep 17 00:00:00 2001
> From: Nagy Gabor <ngaba@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@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

_______________________________________________
pacman-dev mailing list
pacman-dev@archlinux.org
http://archlinux.org/mailman/listinfo/pacman-dev

Xavier 04-21-2008 09:43 AM

Kill compute_requiredby usage in deps.c/can_remove_package()
 
On Mon, Apr 21, 2008 at 10:45 AM, Nagy Gabor <ngaba@bibl.u-szeged.hu> wrote:
>
> Correct. But in deps.c almost all functions have these pointers.
>
> 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.
>
> What shall I change? The commit message?
>

I am not sure what Dan wanted, but my suggestion would be to keep the
patch as is, and change the commit message to something like this :

"In the can_remove_package function, we don't need to compute the
whole requiredby list, we just need to find one member of it that
doesn't belong to the targets list.
That way we get a small speedup and remove the only usage of
alpm_pkg_compute_requiredby in the backend, so that it can be tweaked
for frontend usage."

Then someone could do a separate patch that removes all the useless db
param from deps.c for example, if that is a good idea.

_______________________________________________
pacman-dev mailing list
pacman-dev@archlinux.org
http://archlinux.org/mailman/listinfo/pacman-dev


All times are GMT. The time now is 12:35 AM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.