Implement a more explicit object system

Make every dynamically allocated, opaque data structure inherit from
a common sqfs_object_t structure with common entry points (e.g. destroy).

This removes tons of public API functions and replaces them with a
simple sqfs_destroy instead. If semantics of the (until now implicit)
object system need to be extended, it can be much more conveniantely
done this way.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 18 insertions, 6 deletions

diff --git a/lib/sqfs/id_table.c b/lib/sqfs/id_table.c
index 8c30964..86f2809 100644
--- a/lib/sqfs/id_table.c
+++ b/lib/sqfs/id_table.c
@@ -17,23 +17,35 @@
 #include <string.h>
 
 struct sqfs_id_table_t {
+	sqfs_object_t base;
+
 	sqfs_u32 *ids;
 	size_t num_ids;
 	size_t max_ids;
 };
 
+static void id_table_destroy(sqfs_object_t *obj)
+{
+	sqfs_id_table_t *tbl = (sqfs_id_table_t *)obj;
+
+	free(tbl->ids);
+	free(tbl);
+}
+
 sqfs_id_table_t *sqfs_id_table_create(sqfs_u32 flags)
 {
+	sqfs_id_table_t *tbl;
+
 	if (flags != 0)
 		return NULL;
 
-	return calloc(1, sizeof(sqfs_id_table_t));
-}
+	tbl = calloc(1, sizeof(sqfs_id_table_t));
 
-void sqfs_id_table_destroy(sqfs_id_table_t *tbl)
-{
-	free(tbl->ids);
-	free(tbl);
+	if (tbl != NULL) {
+		((sqfs_object_t *)tbl)->destroy = id_table_destroy;
+	}
+
+	return tbl;
 }
 
 int sqfs_id_table_id_to_index(sqfs_id_table_t *tbl, sqfs_u32 id, sqfs_u16 *out)