libalpm: introduce get_sync_pkg_ops() helper

Currently default_pkg_ops is accessed in two different ways.

There is get_file_pkg_ops (in be_package.c) creating a local once-off
'tweaked' copy. As well as load_pkg_for_entry (be_sync.c) which modifies
in-place and uses default_pkg_ops.

This seems rather misleading and fragile approach. Introduce a helper
for the second use-case so that default_pkg_ops is handled consistently
and essentially remains unchanged throughout.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Allan McRae <allan@archlinux.org>

1 files changed, 17 insertions, 2 deletions

diff --git a/lib/libalpm/be_sync.c b/lib/libalpm/be_sync.c
index 225df76d..37000dec 100644
--- a/lib/libalpm/be_sync.c
+++ b/lib/libalpm/be_sync.c
@@ -281,6 +281,22 @@ static int _sync_get_validation(alpm_pkg_t *pkg)
 	return pkg->validation;
 }
 
+/** Package sync operations struct accessor. We implement this as a method
+ * because we want to reuse the majority of the default_pkg_ops struct and
+ * add only a few operations of our own on top.
+ */
+static struct pkg_operations *get_sync_pkg_ops(void)
+{
+	static struct pkg_operations sync_pkg_ops;
+	static int sync_pkg_ops_initalized = 0;
+	if(!sync_pkg_ops_initalized) {
+		sync_pkg_ops = default_pkg_ops;
+		sync_pkg_ops.get_validation = _sync_get_validation;
+		sync_pkg_ops_initalized = 1;
+	}
+	return &sync_pkg_ops;
+}
+
 static alpm_pkg_t *load_pkg_for_entry(alpm_db_t *db, const char *entryname,
 		const char **entry_filename, alpm_pkg_t *likely_pkg)
 {
@@ -321,8 +337,7 @@ static alpm_pkg_t *load_pkg_for_entry(alpm_db_t *db, const char *entryname,
 
 		pkg->origin = ALPM_PKG_FROM_SYNCDB;
 		pkg->origin_data.db = db;
-		pkg->ops = &default_pkg_ops;
-		pkg->ops->get_validation = _sync_get_validation;
+		pkg->ops = get_sync_pkg_ops();
 		pkg->handle = db->handle;
 
 		/* add to the collection */