[traffxml] Store message cache in file

So far only API and tests, and without decoded segments

Signed-off-by: mvglasow <michael -at- vonglasow.com>

map/traffic_manager.cpp

@@ -107,6 +107,12 @@ void TrafficManager::Teardown()
   m_thread.join();
 }
 
+std::map<std::string, traffxml::TraffMessage> TrafficManager::GetMessageCache()
+{
+  std::lock_guard<std::mutex> lock(m_mutex);
+  return m_messageCache;
+}
+
 TrafficManager::TrafficState TrafficManager::GetState() const
 {
   return m_state;

map/traffic_manager.hpp

@@ -111,6 +111,17 @@ public:
 
   void Teardown();
 
+  /**
+   * @brief Returns a copy of the cache of all currently active TraFF messages.
+   *
+   * For testing purposes.
+   *
+   * Keys are message IDs, values are messages.
+   *
+   * This method is safe to call from any thread.
+   */
+  std::map<std::string, traffxml::TraffMessage> GetMessageCache();
+
   TrafficState GetState() const;
   void SetStateListener(TrafficStateChangedFn const & onStateChangedFn);