tdb: add tdb_freelist_merge_adjacent()

[samba.git] / lib / tdb / common / freelist.c

diff --git a/lib/tdb/common/freelist.c b/lib/tdb/common/freelist.c
index 9b508757ebc93dffc821d31bf779d70331c35c56..89ea371cbb54dfde2e03903fb0a6019b62a4c617 100644 (file)
--- a/lib/tdb/common/freelist.c
+++ b/lib/tdb/common/freelist.c
@@ -611,6 +611,65 @@ blocking_freelist_allocate:
        return ret;
 }
 
+/**
+ * Merge adjacent records in the freelist.
+ */
+static int tdb_freelist_merge_adjacent(struct tdb_context *tdb,
+                                      int *count_records, int *count_merged)
+{
+       tdb_off_t cur, next;
+       int count = 0;
+       int merged = 0;
+       int ret;
+
+       ret = tdb_lock(tdb, -1, F_RDLCK);
+       if (ret == -1) {
+               return -1;
+       }
+
+       cur = FREELIST_TOP;
+       while (tdb_ofs_read(tdb, cur, &next) == 0 && next != 0) {
+               tdb_off_t next2;
+
+               count++;
+
+               ret = check_merge_ptr_with_left_record(tdb, next, &next2);
+               if (ret == -1) {
+                       goto done;
+               }
+               if (ret == 1) {
+                       /*
+                        * merged:
+                        * now let cur->next point to next2 instead of next
+                        */
+
+                       ret = tdb_ofs_write(tdb, cur, &next2);
+                       if (ret != 0) {
+                               goto done;
+                       }
+
+                       next = next2;
+                       merged++;
+               }
+
+               cur = next;
+       }
+
+       if (count_records != NULL) {
+               *count_records = count;
+       }
+
+       if (count_merged != NULL) {
+               *count_merged = merged;
+       }
+
+       ret = 0;
+
+done:
+       tdb_unlock(tdb, -1, F_RDLCK);
+       return ret;
+}
+
 /*
    return the size of the freelist - used to decide if we should repack
 */