[OMON-376] Use separate streams in StdOut backend (#213)

Author: awegrzyn

CMakeLists.txt

@@ -17,7 +17,7 @@ endif()
 
 # Define project
 project(Monitoring
-  VERSION 3.0.6
+  VERSION 3.3.4
   DESCRIPTION "O2 Monitoring library"
   LANGUAGES CXX
 )

src/Backends/StdOut.cxx

@@ -40,7 +40,7 @@ inline unsigned long StdOut::convertTimestamp(const std::chrono::time_point<std:
     .count();
 }
 
-StdOut::StdOut(const std::string& prefix) : mStream(), mPrefix(prefix)
+StdOut::StdOut(const std::string& prefix) : mPrefix(prefix)
 {
   setVerbosisty(Verbosity::Debug);
   MonLogger::Get() << "StdOut backend initialized" << MonLogger::End();
@@ -65,6 +65,7 @@ void StdOut::send(std::vector<Metric>&& metrics)
 
 void StdOut::send(const Metric& metric)
 {
+  std::ostringstream mStream;
   mStream << "[" << mPrefix << "] "  << metric.getName();
   for (auto& value : metric.getValues()) {
     auto stringValue = std::visit(overloaded{

src/Backends/StdOut.h

@@ -53,9 +53,6 @@ class StdOut final : public Backend
   void addGlobalTag(std::string_view name, std::string_view value) override;
 
  private:
-  /// Metric stream
-  std::ostringstream mStream;
-
   /// Converts timestamp to unsigned long (miliseconds from epoch)
   /// \param timestamp    timestamp in std::chrono::time_point format
   /// \return             timestamp as unsigned long (miliseconds from epoch)