Rework loadCache() to accelerate getPublicSensorsByWildcard() calls

lib/include_internal/sensorconfig_internal.h

@@ -49,9 +49,9 @@ protected:
   Connection* connection;
   CassSession* session;
 
-  typedef std::unordered_map<std::string, std::reference_wrapper<PublicSensor>> SensorMap_t;
+  typedef std::unordered_map<std::string, PublicSensor> SensorMap_t;
   SensorMap_t sensorMapByName;
-  std::list<PublicSensor> sensorList;
+  std::list<std::string> sensorList;
 
   bool validateSensorPattern(const char* sensorPattern);
   bool validateSensorPublicName(std::string publicName);

lib/src/sensorconfig.cpp

@@ -306,17 +306,17 @@ bool SensorConfigImpl::validateSensorPublicName(std::string publicName)
 
 SCError SensorConfigImpl::loadCache()
 {
-    sensorList.clear();
-    sensorMapByName.clear();
-
-    SCError rc = getPublicSensorsVerbose(sensorList);
-    if (rc != SC_OK) {
-        return rc;
+    if (sensorList.size() != 0) {
+	return SC_OK;
     } else {
-        for (auto& s: sensorList) {
-            sensorMapByName.insert(std::make_pair(s.name, std::ref(s)));
-        }
-        return SC_OK;
+#ifdef DEBUG
+	TimeStamp ts;
+#endif
+	SCError ret = getPublicSensorNames(sensorList);
+#ifdef DEBUG
+	std::cerr << "loadCache: " << sensorList.size() << " sensors loaded in " << TimeStamp().getRaw() - ts.getRaw() << " ns" << std::endl;
+#endif
+	return ret;
     }
 }
 
@@ -1063,9 +1063,8 @@ SCError SensorConfigImpl::getPublicSensorByName(PublicSensor& sensor, const char
             sensor.ttl = ttl;
             sensor.operations = operations;
 
-            /* Add to sensorPropertyCache for later use */
-            sensorList.push_back(sensor);
-            sensorMapByName.insert(std::make_pair(publicName, std::ref(sensorList.back())));
+            /* Add to sensorMap for later use */
+            sensorMapByName.insert(std::make_pair(publicName, sensor));
         }
         else {
             cass_result_free(result);
@@ -1096,8 +1095,7 @@ SCError SensorConfigImpl::getPublicSensorsByWildcard(std::list<PublicSensor>& se
         }
         return err;
     } else {
-	std::list<std::string> sensorNames;
-        if ((err = getPublicSensorNames(sensorNames)) == SC_OK) {
+	if (loadCache() == SC_OK) {
             std::string w("^");
             while (*wildcard != 0) {
                 switch (*wildcard) {
@@ -1123,7 +1121,7 @@ SCError SensorConfigImpl::getPublicSensorsByWildcard(std::list<PublicSensor>& se
             }
 
             boost::regex r(w, boost::regex::basic);
-	    for (auto s: sensorNames) {
+	    for (auto s: sensorList) {
                 if (boost::regex_match(s, r)) {
 		    PublicSensor ps;
 		    getPublicSensorByName(ps, s.c_str());