diff options
Diffstat (limited to 'src/backend/nodes/list.c')
| -rw-r--r-- | src/backend/nodes/list.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/src/backend/nodes/list.c b/src/backend/nodes/list.c index 279d7a91c4b..0b8686d262d 100644 --- a/src/backend/nodes/list.c +++ b/src/backend/nodes/list.c @@ -1298,6 +1298,34 @@ list_concat_unique_oid(List *list1, const List *list2) } /* + * Remove adjacent duplicates in a list of OIDs. + * + * It is caller's responsibility to have sorted the list to bring duplicates + * together, perhaps via list_sort(list, list_oid_cmp). + */ +void +list_deduplicate_oid(List *list) +{ + int len; + + Assert(IsOidList(list)); + len = list_length(list); + if (len > 1) + { + ListCell *elements = list->elements; + int i = 0; + + for (int j = 1; j < len; j++) + { + if (elements[i].oid_value != elements[j].oid_value) + elements[++i].oid_value = elements[j].oid_value; + } + list->length = i + 1; + } + check_list_invariants(list); +} + +/* * Free all storage in a list, and optionally the pointed-to elements */ static void @@ -1444,3 +1472,19 @@ list_sort(List *list, list_sort_comparator cmp) if (len > 1) qsort(list->elements, len, sizeof(ListCell), (qsort_comparator) cmp); } + +/* + * list_sort comparator for sorting a list into ascending OID order. + */ +int +list_oid_cmp(const ListCell *p1, const ListCell *p2) +{ + Oid v1 = lfirst_oid(p1); + Oid v2 = lfirst_oid(p2); + + if (v1 < v2) + return -1; + if (v1 > v2) + return 1; + return 0; +} |