X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Ftdb1_io.c;h=488f3d847837e2009b4eee2968932c3dbbfaa080;hp=ceae5285a7a1bb0e4607cca4ec8d81ac45aa994a;hb=695e2ae319052ceb410ef00d0181aa607f1ceb6d;hpb=72021c1262ae0c1826891a149d8196b18fa7961f

diff --git a/ccan/tdb2/tdb1_io.c b/ccan/tdb2/tdb1_io.c
index ceae5285..488f3d84 100644
--- a/ccan/tdb2/tdb1_io.c
+++ b/ccan/tdb2/tdb1_io.c
@@ -330,42 +330,51 @@ static int tdb1_expand_file(struct tdb_context *tdb, tdb1_off_t size, tdb1_off_t
 }
 
 
-/* expand the database at least size bytes by expanding the underlying
-   file and doing the mmap again if necessary */
-int tdb1_expand(struct tdb_context *tdb, tdb1_off_t size)
+/* You need 'size', this tells you how much you should expand by. */
+tdb1_off_t tdb1_expand_adjust(tdb1_off_t map_size, tdb1_off_t size, int page_size)
 {
-	struct tdb1_record rec;
-	tdb1_off_t offset, new_size, top_size, map_size;
-
-	if (tdb1_lock(tdb, -1, F_WRLCK) == -1) {
-		tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
-			   "lock failed in tdb1_expand");
-		return -1;
-	}
-
-	/* must know about any previous expansions by another process */
-	tdb->tdb1.io->tdb1_oob(tdb, tdb->file->map_size, 1, 1);
+	tdb1_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 = tdb->file->map_size + size * 2;
+		top_size = map_size + size * 2;
 	} else {
-		top_size = tdb->file->map_size + size * 100;
+		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 (tdb->file->map_size > 100 * 1024 * 1024) {
-		map_size = tdb->file->map_size * 1.10;
+	if (map_size > 100 * 1024 * 1024) {
+		new_size = map_size * 1.10;
 	} else {
-		map_size = tdb->file->map_size * 1.25;
+		new_size = map_size * 1.25;
 	}
 
 	/* Round the database up to a multiple of the page size */
-	new_size = MAX(top_size, map_size);
-	size = TDB1_ALIGN(new_size, tdb->tdb1.page_size) - tdb->file->map_size;
+	new_size = MAX(top_size, new_size);
+	return TDB1_ALIGN(new_size, page_size) - map_size;
+}
+
+/* expand the database at least size bytes by expanding the underlying
+   file and doing the mmap again if necessary */
+int tdb1_expand(struct tdb_context *tdb, tdb1_off_t size)
+{
+	struct tdb1_record rec;
+	tdb1_off_t offset;
+
+	if (tdb1_lock(tdb, -1, F_WRLCK) == -1) {
+		tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
+			   "lock failed in tdb1_expand");
+		return -1;
+	}
+
+	/* must know about any previous expansions by another process */
+	tdb->tdb1.io->tdb1_oob(tdb, tdb->file->map_size, 1, 1);
+
+	size = tdb1_expand_adjust(tdb->file->map_size, size,
+				  tdb->tdb1.page_size);
 
 	if (!(tdb->flags & TDB_INTERNAL))
 		tdb1_munmap(tdb);