Added preallocation of vectors in RuleDrawer

1 files changed, 8 insertions, 1 deletions

diff --git a/drape_frontend/rule_drawer.cpp b/drape_frontend/rule_drawer.cpp
index 5ba75f0d91..f78fcb7086 100644
--- a/drape_frontend/rule_drawer.cpp
+++ b/drape_frontend/rule_drawer.cpp
@@ -29,6 +29,8 @@
 namespace
 {
 int constexpr kOutlineMinZoomLevel = 16;
+                                               // 10  11    12     13    14    15    16    17    18   19
+vector<size_t> const kAverageSegmentsCount = { 10000, 5000, 10000, 5000, 2500, 5000, 2000, 1000, 500, 500 };
 
 df::BaseApplyFeature::HotelData ExtractHotelData(FeatureType const & f)
 {
@@ -65,7 +67,12 @@ void ExtractTrafficGeometry(FeatureType const & f, df::RoadClass const & roadCla
   static vector<uint8_t> directions = {traffic::TrafficInfo::RoadSegmentId::kForwardDirection,
                                        traffic::TrafficInfo::RoadSegmentId::kReverseDirection};
   auto & segments = geometry[f.GetID().m_mwmId];
-  segments.reserve(segments.size() + directions.size() * (polyline.GetSize() - 1));
+
+  int const index = zoomLevel - 10; // 10 - the first zoom level in kAverageSegmentsCount.
+  ASSERT_GREATER(index, 0, ());
+  ASSERT_LESS(index, kAverageSegmentsCount.size(), ());
+  segments.reserve(kAverageSegmentsCount[index]);
+
   for (uint16_t segIndex = 0; segIndex + 1 < static_cast<uint16_t>(polyline.GetSize()); ++segIndex)
   {
     for (size_t dirIndex = 0; dirIndex < directions.size(); ++dirIndex)