alpm/dep: add alpm_find_dbs_satisfier

This is a public interface for resolvedep. It looks nicer to expose it
this way rather than through sync_target.

This function can also be helpful for external tools as it should give
good results close to how pacman select a package for satisfying a given
dep.

Signed-off-by: Xavier Chantry <chantry.xavier@gmail.com>

2 files changed, 23 insertions, 0 deletions

diff --git a/lib/libalpm/alpm.h b/lib/libalpm/alpm.h
index 6724bf78..e33aab24 100644
--- a/lib/libalpm/alpm.h
+++ b/lib/libalpm/alpm.h
@@ -439,6 +439,7 @@ typedef enum _pmdepmod_t {
 alpm_list_t *alpm_checkdeps(alpm_list_t *pkglist, int reversedeps,
 		alpm_list_t *remove, alpm_list_t *upgrade);
 pmpkg_t *alpm_find_satisfier(alpm_list_t *pkgs, const char *depstring);
+pmpkg_t *alpm_find_dbs_satisfier(alpm_list_t *dbs, const char *depstring);
 
 const char *alpm_miss_get_target(const pmdepmissing_t *miss);
 pmdepend_t *alpm_miss_get_dep(pmdepmissing_t *miss);
diff --git a/lib/libalpm/deps.c b/lib/libalpm/deps.c
index 28a51bcf..609200f3 100644
--- a/lib/libalpm/deps.c
+++ b/lib/libalpm/deps.c
@@ -494,6 +494,28 @@ void _alpm_recursedeps(pmdb_t *db, alpm_list_t *targs, int include_explicit)
 	}
 }
 
+/** Find a package satisfying a specified dependency.
+ * First look for a literal, going through each db one by one. Then look for
+ * providers. The first satisfier found is returned.
+ * The dependency can include versions with depmod operators.
+ * @param dbs an alpm_list_t* of pmdb_t where the satisfier will be searched
+ * @param depstring package or provision name, versioned or not
+ * @return a pmpkg_t* satisfying depstring
+ */
+pmpkg_t SYMEXPORT *alpm_find_dbs_satisfier(alpm_list_t *dbs, const char *depstring)
+{
+	pmdepend_t *dep;
+	pmpkg_t *pkg;
+
+	ASSERT(dbs, return(NULL));
+
+	dep = _alpm_splitdep(depstring);
+	ASSERT(dep, return(NULL));
+	pkg = _alpm_resolvedep(dep, dbs, NULL, 1);
+	_alpm_dep_free(dep);
+	return(pkg);
+}
+
 /**
  * helper function for resolvedeps: search for dep satisfier in dbs
  *