utils llist: Added sdb_llist_iter_remove_current().

This function may be used to remove the current (the one returned by the last
sdb_llist_iter_get_next() call) iterator value from the list.

Note, that this function is not safe if another iterator is used in parallel
at the same time.

diff --git a/src/include/utils/llist.h b/src/include/utils/llist.h
index 104c9e45ab94c2e08a8aca2feb5e84ba57a2e1db..2742139f17db051d12b36c279889ff0c0bbfb48f 100644 (file)
--- a/src/include/utils/llist.h
+++ b/src/include/utils/llist.h
@@ -173,7 +173,8 @@ sdb_llist_remove(sdb_llist_t *list,
 sdb_object_t *
 sdb_llist_shift(sdb_llist_t *list);
 
-/* sdb_llist_get_iter, sdb_llist_iter_has_next, sdb_llist_iter_get_next:
+/*
+ * sdb_llist_get_iter, sdb_llist_iter_has_next, sdb_llist_iter_get_next:
  * Iterate through the list, element by element.
  *
  * sdb_llist_iter_get_next returns NULL if there is no next element.
@@ -188,6 +189,20 @@ sdb_llist_iter_has_next(sdb_llist_iter_t *iter);
 sdb_object_t *
 sdb_llist_iter_get_next(sdb_llist_iter_t *iter);
 
+/*
+ * sdb_llist_iter_remove_current:
+ * Remove the current object from the list, that is, the object which was
+ * returned by the last call to sdb_llist_iter_get_next().
+ *
+ * This operation is not safe if another iterator is in use at the same time.
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a negative value else
+ */
+int
+sdb_llist_iter_remove_current(sdb_llist_iter_t *iter);
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif

diff --git a/src/utils/llist.c b/src/utils/llist.c
index 0af9c8cb11bec4346b96c557275b4a813ccfd618..0a4665d09296c2387bcf1f369f81f5e751c20fa4 100644 (file)
--- a/src/utils/llist.c
+++ b/src/utils/llist.c
@@ -434,5 +434,29 @@ sdb_llist_iter_get_next(sdb_llist_iter_t *iter)
        return obj;
 } /* sdb_llist_iter_get_next */
 
+int
+sdb_llist_iter_remove_current(sdb_llist_iter_t *iter)
+{
+       sdb_llist_elem_t *elem;
+
+       if ((! iter) || (! iter->list))
+               return -1;
+
+       pthread_rwlock_wrlock(&iter->list->lock);
+
+       if (! iter->elem) /* reached end of list */
+               elem = iter->list->tail;
+       else
+               elem = iter->elem->prev;
+       if (elem)
+               sdb_llist_remove_elem(iter->list, elem);
+
+       pthread_rwlock_unlock(&iter->list->lock);
+
+       if (! elem)
+               return -1;
+       return 0;
+} /* sdb_llist_iter_remove */
+
 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 

diff --git a/t/utils/llist_test.c b/t/utils/llist_test.c
index 638d2fbdbeef1affe64e15753a7e6ca08cd7633e..ede8200a42a325d3f22707eb001febdc8ac9b51e 100644 (file)
--- a/t/utils/llist_test.c
+++ b/t/utils/llist_test.c
@@ -233,6 +233,41 @@ START_TEST(test_sdb_llist_iter)
 }
 END_TEST
 
+START_TEST(test_sdb_llist_iter_remove)
+{
+       sdb_llist_iter_t *iter;
+       sdb_object_t *check;
+       size_t i;
+
+       populate();
+
+       iter = sdb_llist_get_iter(list);
+       fail_unless(iter != NULL,
+                       "sdb_llist_get_iter() did not return an iterator");
+
+       i = 0;
+       while (sdb_llist_iter_has_next(iter)) {
+               check = sdb_llist_iter_get_next(iter);
+               fail_unless(check == &golden_data[i],
+                               "sdb_llist_iter_get_next() = %p; expected: %p",
+                               check, &golden_data[i]);
+
+               sdb_llist_iter_remove_current(iter);
+               ++i;
+       }
+       sdb_llist_iter_destroy(iter);
+
+       fail_unless(i == (size_t)SDB_STATIC_ARRAY_LEN(golden_data),
+                       "iterated for %zu steps; expected: %i",
+                       i, SDB_STATIC_ARRAY_LEN(golden_data));
+
+       /* all elements should be removed */
+       check = sdb_llist_shift(list);
+       fail_unless(check == NULL,
+                       "sdb_llist_shift() = %p; expected: NULL", check);
+}
+END_TEST
+
 Suite *
 util_llist_suite(void)
 {
@@ -249,6 +284,7 @@ util_llist_suite(void)
        tcase_add_test(tc, test_sdb_llist_search);
        tcase_add_test(tc, test_sdb_llist_shift);
        tcase_add_test(tc, test_sdb_llist_iter);
+       tcase_add_test(tc, test_sdb_llist_iter_remove);
        suite_add_tcase(s, tc);
 
        return s;