From 8ef414a7f38a04cfc11df44adaedaf3126fa3878 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Sur=C3=BD?= <ondrej@isc.org>
Date: Mon, 29 Jan 2024 16:36:30 +0100
Subject: [PATCH] Optimize the slabheader placement for certain RRTypes

Mark the infrastructure RRTypes as "priority" types and place them at
the beginning of the rdataslab header data graph.  The non-priority
types either go right after the priority types (if any).

(cherry picked from commit 3ac482be7fd058d284e89873021339579fad0615)

Conflict:NA
Reference:https://gitlab.isc.org/isc-projects/bind9/-/commit/8ef414a7f38a04cfc11df44adaedaf3126fa3878

---
 lib/dns/rbtdb.c | 44 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 42 insertions(+), 2 deletions(-)

diff --git a/lib/dns/rbtdb.c b/lib/dns/rbtdb.c
index 7793be8..bc0f8d8 100644
--- a/lib/dns/rbtdb.c
+++ b/lib/dns/rbtdb.c
@@ -906,6 +906,30 @@ set_ttl(dns_rbtdb_t *rbtdb, rdatasetheader_t *header, dns_ttl_t newttl) {
 	}
 }
 
+static bool
+prio_type(rbtdb_rdatatype_t type) {
+	switch (type) {
+	case dns_rdatatype_soa:
+	case RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_soa):
+	case dns_rdatatype_a:
+	case RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_a):
+	case dns_rdatatype_aaaa:
+	case RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_aaaa):
+	case dns_rdatatype_nsec:
+	case RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_nsec):
+	case dns_rdatatype_nsec3:
+	case RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_nsec3):
+	case dns_rdatatype_ns:
+	case RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_ns):
+	case dns_rdatatype_ds:
+	case RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_ds):
+	case dns_rdatatype_cname:
+	case RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_cname):
+		return (true);
+	}
+	return (false);
+}
+
 /*%
  * These functions allow the heap code to rank the priority of each
  * element.  It returns true if v1 happens "sooner" than v2.
@@ -6167,6 +6191,7 @@ add32(dns_rbtdb_t *rbtdb, dns_rbtnode_t *rbtnode, const dns_name_t *nodename,
 	rbtdb_changed_t *changed = NULL;
 	rdatasetheader_t *topheader = NULL, *topheader_prev = NULL;
 	rdatasetheader_t *header = NULL, *sigheader = NULL;
+	rdatasetheader_t *prioheader = NULL;
 	unsigned char *merged = NULL;
 	isc_result_t result;
 	bool header_nx;
@@ -6313,6 +6338,9 @@ add32(dns_rbtdb_t *rbtdb, dns_rbtnode_t *rbtnode, const dns_name_t *nodename,
 	for (topheader = rbtnode->data; topheader != NULL;
 	     topheader = topheader->next)
 	{
+		if (prio_type(topheader->type)) {
+			prioheader = topheader;
+		}
 		if (topheader->type == newheader->type ||
 		    topheader->type == negtype)
 		{
@@ -6679,9 +6707,21 @@ find_header:
 			/*
 			 * No rdatasets of the given type exist at the node.
 			 */
-			newheader->next = rbtnode->data;
 			newheader->down = NULL;
-			rbtnode->data = newheader;
+
+			if (prio_type(newheader->type)) {
+				/* This is a priority type, prepend it */
+				newheader->next = rbtnode->data;
+				rbtnode->data = newheader;
+			} else if (prioheader != NULL) {
+				/* Append after the priority headers */
+				newheader->next = prioheader->next;
+				prioheader->next = newheader;
+			} else {
+				/* There were no priority headers */
+				newheader->next = rbtnode->data;
+				rbtnode->data = newheader;
+			}
 		}
 	}
 
-- 
2.33.0