From 330d3aa1a2c740dfa31bed3a6ed6b5f88e5426ad Mon Sep 17 00:00:00 2001
From: Sebastian Falbesoner <sebastian.falbesoner@gmail.com>
Date: Mon, 6 Sep 2021 00:10:31 +0200
Subject: [PATCH] refactor: net: avoid duplicate map lookups to `mapLocalHost`

---
 src/net.cpp | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/src/net.cpp b/src/net.cpp
index 9b1e17c587d..cbd09b770ea 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -190,8 +190,8 @@ CAddress GetLocalAddress(const CNetAddr *paddrPeer, ServiceFlags nLocalServices)
 static int GetnScore(const CService& addr)
 {
     LOCK(cs_mapLocalHost);
-    if (mapLocalHost.count(addr) == 0) return 0;
-    return mapLocalHost[addr].nScore;
+    const auto it = mapLocalHost.find(addr);
+    return (it != mapLocalHost.end()) ? it->second.nScore : 0;
 }
 
 // Is our peer's addrLocal potentially useful as an external IP source?
@@ -243,10 +243,10 @@ bool AddLocal(const CService& addr, int nScore)
 
     {
         LOCK(cs_mapLocalHost);
-        bool fAlready = mapLocalHost.count(addr) > 0;
-        LocalServiceInfo &info = mapLocalHost[addr];
-        if (!fAlready || nScore >= info.nScore) {
-            info.nScore = nScore + (fAlready ? 1 : 0);
+        const auto [it, is_newly_added] = mapLocalHost.emplace(addr, LocalServiceInfo());
+        LocalServiceInfo &info = it->second;
+        if (is_newly_added || nScore >= info.nScore) {
+            info.nScore = nScore + (is_newly_added ? 0 : 1);
             info.nPort = addr.GetPort();
         }
     }
@@ -288,12 +288,10 @@ bool IsReachable(const CNetAddr &addr)
 /** vote for a local address */
 bool SeenLocal(const CService& addr)
 {
-    {
-        LOCK(cs_mapLocalHost);
-        if (mapLocalHost.count(addr) == 0)
-            return false;
-        mapLocalHost[addr].nScore++;
-    }
+    LOCK(cs_mapLocalHost);
+    const auto it = mapLocalHost.find(addr);
+    if (it == mapLocalHost.end()) return false;
+    ++it->second.nScore;
     return true;
 }