From 6493dfc057f575588d121c87e6dea65a7319e897 Mon Sep 17 00:00:00 2001
From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Mon, 1 Jul 2019 14:57:47 +0200
Subject: [PATCH] rec: Small speed improvements in the SyncRes

---
 pdns/syncres.cc | 12 ++++++++----
 pdns/syncres.hh | 12 ++++++------
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/pdns/syncres.cc b/pdns/syncres.cc
index a9d40cab8..2750b4d62 100644
--- a/pdns/syncres.cc
+++ b/pdns/syncres.cc
@@ -999,19 +999,19 @@ void SyncRes::getBestNSFromCache(const DNSName &qname, const QType& qtype, vecto
           }
         }
 
-        if(beenthere.count(answer)) {
+        auto insertionPair = beenthere.insert(std::move(answer));
+        if(!insertionPair.second) {
 	  brokeloop=true;
           LOG(prefix<<qname<<": We have NS in cache for '"<<subdomain<<"' but part of LOOP (already seen "<<answer.qname<<")! Trying less specific NS"<<endl);
 	  ;
           if(doLog())
             for( set<GetBestNSAnswer>::const_iterator j=beenthere.begin();j!=beenthere.end();++j) {
-	      bool neo = !(*j< answer || answer<*j);
+	      bool neo = (j == insertionPair.first);
 	      LOG(prefix<<qname<<": beenthere"<<(neo?"*":"")<<": "<<j->qname<<"|"<<DNSRecordContent::NumberToType(j->qtype)<<" ("<<(unsigned int)j->bestns.size()<<")"<<endl);
             }
           bestns.clear();
         }
         else {
-	  beenthere.insert(answer);
           LOG(prefix<<qname<<": We have NS in cache for '"<<subdomain<<"' (flawedNSSet="<<*flawedNSSet<<")"<<endl);
           return;
         }
@@ -1033,6 +1033,10 @@ void SyncRes::getBestNSFromCache(const DNSName &qname, const QType& qtype, vecto
 
 SyncRes::domainmap_t::const_iterator SyncRes::getBestAuthZone(DNSName* qname) const
 {
+  if (t_sstorage.domainmap->empty()) {
+    return t_sstorage.domainmap->end();
+  }
+
   SyncRes::domainmap_t::const_iterator ret;
   do {
     ret=t_sstorage.domainmap->find(*qname);
@@ -1045,7 +1049,6 @@ SyncRes::domainmap_t::const_iterator SyncRes::getBestAuthZone(DNSName* qname) co
 /** doesn't actually do the work, leaves that to getBestNSFromCache */
 DNSName SyncRes::getBestNSNamesFromCache(const DNSName &qname, const QType& qtype, NsSet& nsset, bool* flawedNSSet, unsigned int depth, set<GetBestNSAnswer>&beenthere)
 {
-  DNSName subdomain(qname);
   DNSName authdomain(qname);
 
   domainmap_t::const_iterator iter=getBestAuthZone(&authdomain);
@@ -1063,6 +1066,7 @@ DNSName SyncRes::getBestNSNamesFromCache(const DNSName &qname, const QType& qtyp
     return authdomain;
   }
 
+  DNSName subdomain(qname);
   vector<DNSRecord> bestns;
   getBestNSFromCache(subdomain, qtype, bestns, flawedNSSet, depth, beenthere);
 
diff --git a/pdns/syncres.hh b/pdns/syncres.hh
index d0edf346d..bbe35beef 100644
--- a/pdns/syncres.hh
+++ b/pdns/syncres.hh
@@ -67,7 +67,7 @@ extern GlobalStateHolder<NetmaskGroup> g_dontThrottleNetmasks;
 
 class RecursorLua4;
 
-typedef map<
+typedef std::unordered_map<
   DNSName,
   pair<
     vector<ComboAddress>,
@@ -337,7 +337,7 @@ public:
     ComboAddress d_best;
   };
 
-  typedef map<DNSName, DecayingEwmaCollection> nsspeeds_t;
+  typedef std::unordered_map<DNSName, DecayingEwmaCollection> nsspeeds_t;
   typedef map<ComboAddress, EDNSStatus> ednsstatus_t;
 
   vState getDSRecords(const DNSName& zone, dsmap_t& ds, bool onlyTA, unsigned int depth, bool bogusOnNXD=true, bool* foundCut=nullptr);
@@ -385,7 +385,7 @@ public:
     void addSOA(std::vector<DNSRecord>& records) const;
   };
 
-  typedef map<DNSName, AuthDomain> domainmap_t;
+  typedef std::unordered_map<DNSName, AuthDomain> domainmap_t;
   typedef Throttle<boost::tuple<ComboAddress,DNSName,uint16_t> > throttle_t;
   typedef Counters<ComboAddress> fails_t;
 
@@ -781,11 +781,11 @@ private:
   {
     DNSName qname;
     set<pair<DNSName,DNSName> > bestns;
-    uint8_t qtype; // only A and AAAA anyhow
+    uint8_t qtype;
     bool operator<(const GetBestNSAnswer &b) const
     {
-      return boost::tie(qname, qtype, bestns) <
-	boost::tie(b.qname, b.qtype, b.bestns);
+      return boost::tie(qtype, qname, bestns) <
+	boost::tie(b.qtype, b.qname, b.bestns);
     }
   };
 
-- 
2.49.0