Add SensorConfig::loadCache() that loads all published sensors into a list and...

Add SensorConfig::loadCache() that loads all published sensors into a list and creates a map for faster lookup of sensor names

lib/include/dcdb/sensorconfig.h

@@ -101,6 +101,13 @@ protected:
   SensorConfigImpl* impl;
 
 public:
+  /**
+   * @brief Load all published sensors into cache.
+   *
+   * @return               See SCError.
+   */
+  SCError loadCache();
+
   /**
    * @brief Makes a physical sensor public.
    *

lib/include_internal/sensorconfig_internal.h

@@ -27,6 +27,7 @@
 #include <list>
 #include <string>
 #include <unordered_map>
+#include <functional>
 
 #include "cassandra.h"
 
@@ -47,13 +48,15 @@ protected:
   Connection* connection;
   CassSession* session;
 
-  typedef std::unordered_map<std::string, PublicSensor> SensorPropertyCache_t;
-  static SensorPropertyCache_t sensorPropertyCache;
+  typedef std::unordered_map<std::string, std::reference_wrapper<PublicSensor>> SensorMap_t;
+  SensorMap_t sensorMapByName;
+  std::list<PublicSensor> sensorList;
 
   bool validateSensorPattern(const char* sensorPattern);
   bool validateSensorPublicName(std::string publicName);
 
 public:
+  SCError loadCache();
   SCError publishSensor(std::string publicName, std::string sensorPattern);
   SCError publishVirtualSensor(std::string publicName, std::string vSensorExpression, std::string vSensorId, TimeStamp tZero, uint64_t frequency);
   SCError unPublishSensor(std::string publicName);

lib/src/sensorconfig.cpp

@@ -77,6 +77,12 @@ PublicSensor::PublicSensor (const PublicSensor &copy)
 /*
  * SensorConfig functions
  */
+
+SCError SensorConfig::loadCache()
+{
+  return impl->loadCache();
+}
+
 SCError SensorConfig::publishSensor(const char* publicName, const char* sensorPattern)
 {
   return impl->publishSensor(publicName, sensorPattern);
@@ -178,7 +184,6 @@ SensorConfig::~SensorConfig()
 /*
  * SensorConfigImpl protected members and functions
  */
-SensorConfigImpl::SensorPropertyCache_t SensorConfigImpl::sensorPropertyCache;
 
 /*
  * Validate the pattern for a Sensor to be published
@@ -266,6 +271,23 @@ bool SensorConfigImpl::validateSensorPublicName(std::string publicName)
 /*
  * SensorConfigImpl public functions
  */
+
+SCError SensorConfigImpl::loadCache()
+{
+  sensorList.clear();
+  sensorMapByName.clear();
+
+  SCError rc = getPublicSensorsVerbose(sensorList);
+  if (rc != SC_OK) {
+    return rc;
+  } else {
+    for (auto& s: sensorList) {
+      sensorMapByName.insert(std::make_pair(s.name, std::ref(s)));
+    }
+    return SC_OK;
+  }
+}
+
 SCError SensorConfigImpl::publishSensor(std::string publicName, std::string sensorPattern)
 {
   /* Check if the pattern matches the requirements */
@@ -628,8 +650,8 @@ SCError SensorConfigImpl::getPublicSensorsVerbose(std::list<PublicSensor>& publi
 SCError SensorConfigImpl::getPublicSensorByName(PublicSensor& sensor, const char* publicName)
 {
   /* Check if the sensor definition is already in the cache */
-  SensorPropertyCache_t::const_iterator got = sensorPropertyCache.find(publicName);
-  if (got != sensorPropertyCache.end()) {
+  SensorMap_t::const_iterator got = sensorMapByName.find(publicName);
+  if (got != sensorMapByName.end()) {
       sensor = got->second;
       return SC_OK;
   }
@@ -738,7 +760,7 @@ SCError SensorConfigImpl::getPublicSensorByName(PublicSensor& sensor, const char
           sensor.frequency = frequency;
 
           /* Add to sensorPropertyCache for later use */
-          sensorPropertyCache.insert(std::make_pair(publicName, sensor));
+	  sensorMapByName.insert(std::make_pair(publicName, std::ref(sensor)));
       }
       else {
           cass_result_free(result);