improving zonec performance on many zones

[fujiwara at jprs.co.jp]

Hi, folks.

I'm testing NSD server performance on serveral zones and I found zonec
improvement point.

"zonec" needs large compile time for many(10000 or 1 million or more)
zones.

At each SOA RR, namedb_find_zone() is called and each SOA ownername
pointer is always compared with all zones->apex in this function.
As a result, this compare loop runs N(N-1)/2 times. (N = number of zones)

namedb_find_zone() processing time grows dominant as number of zones
 grows.

To fix this, I added one member (zone_type pointer) to domain_type
and record zone pointer to APEX domainname.

This patch needs more memory space(number of ownernames * sizeof(pointer)).
But large number of zones case, it improves "zonec" performance.

--
Fujiwara, Kazunori	JPRS


diff -ub nsd-2.2.1/namedb.c nsd-2.2.1+/namedb.c
--- nsd-2.2.1/namedb.c	Wed Feb  9 19:19:53 2005
+++ nsd-2.2.1+/namedb.c	Mon Apr 18 16:34:23 2005
@@ -43,6 +43,7 @@
 	result->plugin_data = NULL;
 #endif
 	result->is_existing = 0;
+	result->apexzone = NULL;
 	
 	return result;
 }
diff -ub nsd-2.2.1/namedb.h nsd-2.2.1+/namedb.h
--- nsd-2.2.1/namedb.h	Tue Jan  4 21:26:22 2005
+++ nsd-2.2.1+/namedb.h	Mon Apr 18 16:32:46 2005
@@ -52,6 +52,7 @@
 	 * This domain name exists (see wildcard clarification draft).
 	 */
 	unsigned     is_existing : 1;
+	zone_type   *apexzone;
 };
 
 struct zone
diff -ub nsd-2.2.1/zonec.c nsd-2.2.1+/zonec.c
--- nsd-2.2.1/zonec.c	Thu Jan 27 19:38:53 2005
+++ nsd-2.2.1+/zonec.c	Mon Apr 18 17:16:42 2005
@@ -1037,7 +1037,8 @@
 		 * This is a SOA record, start a new zone or continue
 		 * an existing one.
 		 */
-		zone = namedb_find_zone(parser->db, rr->owner);
+		zone = rr->owner->apexzone;
+
 		if (!zone) {
 			/* new zone part */
 			zone = (zone_type *) region_alloc(parser->region,
@@ -1050,6 +1051,8 @@
 			/* insert in front of zone list */
 			zone->next = parser->db->zones;
 			parser->db->zones = zone;
+
+			rr->owner->apexzone = zone;
 		}
 		
 		/* parser part */