+/* You need 'size', this tells you how much you should expand by. */
+tdb_off_t tdb_expand_adjust(tdb_off_t map_size, tdb_off_t size, int page_size)
+{
+ tdb_off_t new_size, top_size;
+
+ /* limit size in order to avoid using up huge amounts of memory for
+ * in memory tdbs if an oddball huge record creeps in */
+ if (size > 100 * 1024) {
+ top_size = map_size + size * 2;
+ } else {
+ top_size = map_size + size * 100;
+ }
+
+ /* always make room for at least top_size more records, and at
+ least 25% more space. if the DB is smaller than 100MiB,
+ otherwise grow it by 10% only. */
+ if (map_size > 100 * 1024 * 1024) {
+ new_size = map_size * 1.10;
+ } else {
+ new_size = map_size * 1.25;
+ }
+
+ /* Round the database up to a multiple of the page size */
+ new_size = MAX(top_size, new_size);
+ return TDB_ALIGN(new_size, page_size) - map_size;
+}