From 331358ba1d336f0e63d78d2b3aa78ec07a020f6b Mon Sep 17 00:00:00 2001
From: Brian Wellington <bwelling@xbill.org>
Date: Thu, 2 Apr 2020 10:32:57 -0700
Subject: [PATCH] Further improve get_rdata_class().

When we find a class-independent type, cache it for both class ANY and
the requested type, to avoid an extra dict lookup the next time.  If we
don't find anything, cache GenericRdata, to avoid extra module loads the
next time.
---
 dns/rdata.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/dns/rdata.py b/dns/rdata.py
index 1110e8f4..4e5d36c3 100644
--- a/dns/rdata.py
+++ b/dns/rdata.py
@@ -339,10 +339,12 @@ def get_rdata_class(rdclass, rdtype):
                                                   'ANY', rdtype_text]))
                     cls = getattr(mod, rdtype_text)
                     _rdata_classes[(dns.rdataclass.ANY, rdtype)] = cls
+                    _rdata_classes[(rdclass, rdtype)] = cls
                 except ImportError:
                     pass
     if not cls:
         cls = GenericRdata
+        _rdata_classes[(rdclass, rdtype)] = cls
     return cls
 
 
-- 
2.47.3