rec: Compare the CacheKey type and place first then the name

We don't care about the actual ordering, so let's do the cheapest
comparisons first then the quite expensive DNSName comparison only
if we really need to.

(cherry picked from commit 186e99c98d195329af05129cd4d6512657edf4bc)

diff --git a/pdns/syncres.cc b/pdns/syncres.cc
index 8e8f747b1cba6cf7a607ea77c70cb7841653c02e..148ee84b8675a7ed40043cda2c9c704a00a26128 100644 (file)
--- a/pdns/syncres.cc
+++ b/pdns/syncres.cc
@@ -1111,7 +1111,7 @@ struct CacheKey
   uint16_t type;
   DNSResourceRecord::Place place;
   bool operator<(const CacheKey& rhs) const {
-    return tie(name, type, place) < tie(rhs.name, rhs.type, rhs.place);
+    return tie(type, place, name) < tie(rhs.type, rhs.place, rhs.name);
   }
 };
 typedef map<CacheKey, CacheEntry> tcache_t;