From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Wed, 23 Jun 2021 10:08:09 +0000 (+0200)
Subject: dnsdist: Don't look up the LMDB dbi by name for every query
X-Git-Tag: dnsdist-1.7.0-alpha1~87^2~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4fc52785940e35477e863eeb5290a0c23e58e898;p=thirdparty%2Fpdns.git

dnsdist: Don't look up the LMDB dbi by name for every query

This yields a ~5% performance improvement for LMDB lookups.
---

diff --git a/pdns/dnsdistdist/dnsdist-kvs.cc b/pdns/dnsdistdist/dnsdist-kvs.cc
index 3b60dfc2ac..35621dd219 100644
--- a/pdns/dnsdistdist/dnsdist-kvs.cc
+++ b/pdns/dnsdistdist/dnsdist-kvs.cc
@@ -77,9 +77,8 @@ bool LMDBKVStore::getValue(const std::string& key, std::string& value)
 {
   try {
     auto transaction = d_env.getROTransaction();
-    auto dbi = transaction->openDB(d_dbName, 0);
     MDBOutVal result;
-    int rc = transaction->get(dbi, MDBInVal(key), result);
+    int rc = transaction->get(d_dbi, MDBInVal(key), result);
     if (rc == 0) {
       value = result.get<std::string>();
       return true;
@@ -98,9 +97,8 @@ bool LMDBKVStore::keyExists(const std::string& key)
 {
   try {
     auto transaction = d_env.getROTransaction();
-    auto dbi = transaction->openDB(d_dbName, 0);
     MDBOutVal result;
-    int rc = transaction->get(dbi, MDBInVal(key), result);
+    int rc = transaction->get(d_dbi, MDBInVal(key), result);
     if (rc == 0) {
       return true;
     }
diff --git a/pdns/dnsdistdist/dnsdist-kvs.hh b/pdns/dnsdistdist/dnsdist-kvs.hh
index f0968b08ab..939be8a4da 100644
--- a/pdns/dnsdistdist/dnsdist-kvs.hh
+++ b/pdns/dnsdistdist/dnsdist-kvs.hh
@@ -165,7 +165,7 @@ public:
 class LMDBKVStore: public KeyValueStore
 {
 public:
-  LMDBKVStore(const std::string& fname, const std::string& dbName): d_env(fname.c_str(), MDB_NOSUBDIR, 0600), d_fname(fname), d_dbName(dbName)
+  LMDBKVStore(const std::string& fname, const std::string& dbName): d_env(fname.c_str(), MDB_NOSUBDIR, 0600), d_dbi(d_env.openDB(dbName, 0)), d_fname(fname), d_dbName(dbName)
   {
   }
 
@@ -174,6 +174,7 @@ public:
 
 private:
   MDBEnv d_env;
+  MDBDbi d_dbi;
   std::string d_fname;
   std::string d_dbName;
 };