tdb2: copy tdb1's changed expansion logic.

[ccan] / ccan / tdb2 / free.c

diff --git a/ccan/tdb2/free.c b/ccan/tdb2/free.c
index 1b2c552a66fecea4a5e3190a4b4d3e1f5fe51cc3..e693fe828ae3bebf801c653184256ace07e9d23e 100644 (file)
--- a/ccan/tdb2/free.c
+++ b/ccan/tdb2/free.c
@@ -876,10 +876,38 @@ enum TDB_ERROR set_header(struct tdb_context *tdb,
        return TDB_SUCCESS;
 }
 
+/* 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)
+{
+       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 */
+       if (new_size < top_size)
+               new_size = top_size;
+       return new_size - map_size;
+}
+
 /* Expand the database. */
 static enum TDB_ERROR tdb_expand(struct tdb_context *tdb, tdb_len_t size)
 {
-       uint64_t old_size, rec_size, map_size;
+       uint64_t old_size;
        tdb_len_t wanted;
        enum TDB_ERROR ecode;
 
@@ -898,35 +926,14 @@ static enum TDB_ERROR tdb_expand(struct tdb_context *tdb, tdb_len_t size)
 
        /* Someone else may have expanded the file, so retry. */
        old_size = tdb->file->map_size;
-       tdb->tdb2.io->oob(tdb, tdb->file->map_size + 1, true);
+       tdb->tdb2.io->oob(tdb, tdb->file->map_size, 1, true);
        if (tdb->file->map_size != old_size) {
                tdb_unlock_expand(tdb, F_WRLCK);
                return TDB_SUCCESS;
        }
 
-       /* 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) {
-               rec_size = size * 2;
-       } else {
-               rec_size = size * 100;
-       }
-
-       /* always make room for at least rec_size more records, and at
-          least 25% more space. if the DB is smaller than 100MiB,
-          otherwise grow it by 10% only. */
-       if (old_size > 100 * 1024 * 1024) {
-               map_size = old_size / 10;
-       } else {
-               map_size = old_size / 4;
-       }
-
-       if (map_size > rec_size) {
-               wanted = map_size;
-       } else {
-               wanted = rec_size;
-       }
-
+       /* Overallocate. */
+       wanted = tdb_expand_adjust(old_size, size);
        /* We need room for the record header too. */
        wanted = adjust_size(0, sizeof(struct tdb_used_record) + wanted);