StatusVector: Prereserve arrays for better performance

common/StatusVector.cpp

@@ -4,9 +4,11 @@
 
 #include "StatusVector.h"
 
-void StatusVector::Clear() {
+void StatusVector::Clear(size_t reserve) {
     std::unique_lock ul(m);
     content.clear();
+    if (reserve > 0)
+        content.reserve(reserve);
 
     mean = NAN;
     count = 0;
@@ -187,15 +189,19 @@ MultiLinePlot StatusVector::GetMaxPlot(int64_t bin_size, float x_start, float x_
     return ret;
 }
 
-void StatusMultiVector::Clear() {
+void StatusMultiVector::Clear(size_t reserve) {
     std::unique_lock ul(m);
+    if (reserve > 0)
+        r = reserve;
     status.clear();
 }
 
 void StatusMultiVector::AddElement(const std::string &s, uint32_t id, float val) {
     std::unique_lock ul(m);
-    if (!status.contains(s))
+    if (!status.contains(s)) {
         status[s] = std::make_unique<StatusVector>();
+        status[s]->Clear(r);
+    }
     status[s]->AddElement(id, val);
 }