utils llist: Let llist_get() increment the reference count.

[sysdb.git] / src / utils / llist.c

diff --git a/src/utils/llist.c b/src/utils/llist.c
index 0a4665d09296c2387bcf1f369f81f5e751c20fa4..f009bcdac43cd30b3ccd51c0d79f953018f16e04 100644 (file)
--- a/src/utils/llist.c
+++ b/src/utils/llist.c
@@ -25,6 +25,10 @@
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#if HAVE_CONFIG_H
+#      include "config.h"
+#endif /* HAVE_CONFIG_H */
+
 #include "utils/llist.h"
 
 #include <assert.h>
@@ -304,6 +308,23 @@ sdb_llist_insert_sorted(sdb_llist_t *list,
        return status;
 } /* sdb_llist_insert_sorted */
 
+sdb_object_t *
+sdb_llist_get(sdb_llist_t *list, size_t i)
+{
+       sdb_llist_elem_t *elem;
+       size_t j;
+
+       if ((! list) || (i >= list->length))
+               return NULL;
+
+       for (elem = list->head, j = 0; j < i; elem = elem->next, ++j)
+               /* iterate */;
+
+       assert(elem);
+       sdb_object_ref(elem->obj);
+       return elem->obj;
+} /* sdb_llist_get */
+
 sdb_object_t *
 sdb_llist_search(sdb_llist_t *list,
                sdb_llist_lookup_cb lookup, const void *user_data)
@@ -427,6 +448,11 @@ sdb_llist_iter_get_next(sdb_llist_iter_t *iter)
 
        pthread_rwlock_rdlock(&iter->list->lock);
 
+       /* XXX: increment ref-cnt for this object?
+        *      also: when letting an element take ownership of next and prev
+        *      elements, this might be a fairly cheap way to implement a weak
+        *      type of snapshotting */
+
        obj = iter->elem->obj;
        iter->elem = iter->elem->next;
 
@@ -458,5 +484,13 @@ sdb_llist_iter_remove_current(sdb_llist_iter_t *iter)
        return 0;
 } /* sdb_llist_iter_remove */
 
+size_t
+sdb_llist_len(sdb_llist_t *list)
+{
+       if (! list)
+               return 0;
+       return list->length;
+} /* sdb_llist_len */
+
 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */