[core] Don't copy TileLayerIndexes on every frame.

Fixes issue #11811 (too much CPU time spent in CrossTileSymbolIndex).
mapbox · May 1, 2018 · a6d70c2 · a6d70c2
1 parent b820ca4
commit a6d70c2
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/mbgl/text/cross_tile_symbol_index.cpp b/src/mbgl/text/cross_tile_symbol_index.cpp
@@ -62,7 +62,7 @@ CrossTileSymbolLayerIndex::CrossTileSymbolLayerIndex() {
 }
 
 bool CrossTileSymbolLayerIndex::addBucket(const OverscaledTileID& tileID, SymbolBucket& bucket, uint32_t& maxCrossTileID) {
-    auto thisZoomIndexes = indexes[tileID.overscaledZ];
+    const auto& thisZoomIndexes = indexes[tileID.overscaledZ];
     auto previousIndex = thisZoomIndexes.find(tileID);
     if (previousIndex != thisZoomIndexes.end()) {
         if (previousIndex->second.bucketInstanceId == bucket.bucketInstanceId) {