Add some more API calls to xtrace

include/xtrace.h

@@ -37,6 +37,8 @@ void StartTrace();
 void StartTrace(std::string tag);
 void StartTrace(std::vector<std::string> tags);
 
+bool IsTracing();
+
 Logger GetLogger(std::string agent);
 
 void log(std::string message);

src/xtrace.cpp

@@ -123,6 +123,10 @@ void XTrace::StartTrace(std::vector<std::string> tags) {
 	sendReport(report);
 }
 
+bool XTrace::IsTracing() {
+	return XTraceBaggage::HasTaskID();
+}
+
 
 XTrace::Logger XTrace::GetLogger(std::string agent) {
 	return XTrace::Logger(agent);