Kill compute_requiredby usage in can_remove_package()

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.

Signed-off-by: Nagy Gabor <ngaba@bibl.u-szeged.hu>
Signed-off-by: Chantry Xavier <shiningxc@gmail.com>
Signed-off-by: Dan McGee <dan@archlinux.org>

1 files changed, 10 insertions, 8 deletions

diff --git a/lib/libalpm/deps.c b/lib/libalpm/deps.c
index 24b17933..b171ccc7 100644
--- a/lib/libalpm/deps.c
+++ b/lib/libalpm/deps.c
@@ -438,7 +438,7 @@ 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);
@@ -460,15 +460,17 @@ 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);