[core] Force getGeometries() return const ref

14 files changed, 34 insertions, 26 deletions

diff --git a/benchmark/src/mbgl/benchmark/stub_geometry_tile_feature.hpp b/benchmark/src/mbgl/benchmark/stub_geometry_tile_feature.hpp
index bff1a23ba8..b8f2ffb5b9 100644
--- a/benchmark/src/mbgl/benchmark/stub_geometry_tile_feature.hpp
+++ b/benchmark/src/mbgl/benchmark/stub_geometry_tile_feature.hpp
@@ -35,7 +35,7 @@ public:
         return properties.count(key) ? properties.at(key) : optional<Value>();
     }
 
-    GeometryCollection getGeometries() const override {
+    const GeometryCollection& getGeometries() const override {
         return geometry;
     }
 };
diff --git a/src/mbgl/annotation/annotation_tile.cpp b/src/mbgl/annotation/annotation_tile.cpp
index 6c3c9eb617..a410adc95e 100644
--- a/src/mbgl/annotation/annotation_tile.cpp
+++ b/src/mbgl/annotation/annotation_tile.cpp
@@ -58,7 +58,7 @@ FeatureIdentifier AnnotationTileFeature::getID() const {
     return data->id;
 }
 
-GeometryCollection AnnotationTileFeature::getGeometries() const {
+const GeometryCollection& AnnotationTileFeature::getGeometries() const {
     return data->geometries;
 }
 
diff --git a/src/mbgl/annotation/annotation_tile.hpp b/src/mbgl/annotation/annotation_tile.hpp
index 1e23fdf98a..741b598a8c 100644
--- a/src/mbgl/annotation/annotation_tile.hpp
+++ b/src/mbgl/annotation/annotation_tile.hpp
@@ -28,7 +28,7 @@ public:
     FeatureType getType() const override;
     optional<Value> getValue(const std::string&) const override;
     FeatureIdentifier getID() const override;
-    GeometryCollection getGeometries() const override;
+    const GeometryCollection& getGeometries() const override;
 
 private:
     std::shared_ptr<const AnnotationTileFeatureData> data;
diff --git a/src/mbgl/geometry/feature_index.cpp b/src/mbgl/geometry/feature_index.cpp
index 3675e8bc6e..b76e02be3f 100644
--- a/src/mbgl/geometry/feature_index.cpp
+++ b/src/mbgl/geometry/feature_index.cpp
@@ -159,7 +159,7 @@ void FeatureIndex::addFeature(
             continue;
         }
 
-        result[layerID].push_back(convertFeature(*geometryTileFeature, tileID));
+        result[layerID].emplace_back(convertFeature(*geometryTileFeature, tileID));
     }
 }
 
diff --git a/src/mbgl/layout/symbol_feature.hpp b/src/mbgl/layout/symbol_feature.hpp
index 72f613d4b6..2c952fc12a 100644
--- a/src/mbgl/layout/symbol_feature.hpp
+++ b/src/mbgl/layout/symbol_feature.hpp
@@ -20,7 +20,7 @@ public:
     optional<Value> getValue(const std::string& key) const override { return feature->getValue(key); };
     std::unordered_map<std::string,Value> getProperties() const override { return feature->getProperties(); };
     FeatureIdentifier getID() const override { return feature->getID(); };
-    GeometryCollection getGeometries() const override { return geometry; };
+    const GeometryCollection& getGeometries() const override { return geometry; };
 
     friend bool operator < (const SymbolFeature& lhs, const SymbolFeature& rhs) {
         return lhs.sortKey <  rhs.sortKey;
diff --git a/src/mbgl/renderer/layers/render_circle_layer.cpp b/src/mbgl/renderer/layers/render_circle_layer.cpp
index cf59319307..4f1620364f 100644
--- a/src/mbgl/renderer/layers/render_circle_layer.cpp
+++ b/src/mbgl/renderer/layers/render_circle_layer.cpp
@@ -167,7 +167,7 @@ bool RenderCircleLayer::queryIntersectsFeature(
         projectQueryGeometry(translatedQueryGeometry, posMatrix, transformState.getSize());
     auto transformedSize = alignWithMap ? size * pixelsToTileUnits : size;
 
-    auto geometry = feature.getGeometries();
+    const auto& geometry = feature.getGeometries();
     for (auto& ring : geometry) {
         for (auto& point : ring) {
             const GeometryCoordinate& transformedPoint = alignWithMap ? point : projectPoint(point, posMatrix, transformState.getSize());
diff --git a/src/mbgl/style/expression/expression.cpp b/src/mbgl/style/expression/expression.cpp
index 1e5b1581d2..4800f6aa7f 100644
--- a/src/mbgl/style/expression/expression.cpp
+++ b/src/mbgl/style/expression/expression.cpp
@@ -17,7 +17,7 @@ public:
     }
     PropertyMap getProperties() const override { return feature.properties; }
     FeatureIdentifier getID() const override { return feature.id; }
-    GeometryCollection getGeometries() const override { return {}; }
+    const GeometryCollection& getGeometries() const override { return geometry; }
     optional<mbgl::Value> getValue(const std::string& key) const override {
         auto it = feature.properties.find(key);
         if (it != feature.properties.end()) {
@@ -25,6 +25,8 @@ public:
         }
         return optional<mbgl::Value>();
     }
+
+    GeometryCollection geometry;
 };
 
 
diff --git a/src/mbgl/tile/geojson_tile_data.hpp b/src/mbgl/tile/geojson_tile_data.hpp
index 3605af9690..21a65144d9 100644
--- a/src/mbgl/tile/geojson_tile_data.hpp
+++ b/src/mbgl/tile/geojson_tile_data.hpp
@@ -25,15 +25,17 @@ public:
         return feature.id;
     }
 
-    GeometryCollection getGeometries() const override {
-        GeometryCollection geometry = apply_visitor(ToGeometryCollection(), feature.geometry);
-
-        // https://github.com/mapbox/geojson-vt-cpp/issues/44
-        if (getType() == FeatureType::Polygon) {
-            geometry = fixupPolygons(geometry);
+    const GeometryCollection& getGeometries() const override {
+        if (!geometry) {
+            geometry = apply_visitor(ToGeometryCollection(), feature.geometry);
+
+            // https://github.com/mapbox/geojson-vt-cpp/issues/44
+            if (getType() == FeatureType::Polygon) {
+                geometry = fixupPolygons(*geometry);
+            }
         }
 
-        return geometry;
+        return *geometry;
     }
 
     optional<Value> getValue(const std::string& key) const override {
@@ -43,6 +45,8 @@ public:
         }
         return optional<Value>();
     }
+
+    mutable optional<GeometryCollection> geometry;
 };
 
 class GeoJSONTileLayer : public GeometryTileLayer {
diff --git a/src/mbgl/tile/geometry_tile.cpp b/src/mbgl/tile/geometry_tile.cpp
index 7f1bed49f4..a431ae423e 100644
--- a/src/mbgl/tile/geometry_tile.cpp
+++ b/src/mbgl/tile/geometry_tile.cpp
@@ -360,7 +360,7 @@ void GeometryTile::querySourceFeatures(
                     continue;
                 }
 
-                result.push_back(convertFeature(*feature, id.canonical));
+                result.emplace_back(convertFeature(*feature, id.canonical));
             }
         }
     }
diff --git a/src/mbgl/tile/geometry_tile_data.cpp b/src/mbgl/tile/geometry_tile_data.cpp
index 680f8d1497..2dda9ecae4 100644
--- a/src/mbgl/tile/geometry_tile_data.cpp
+++ b/src/mbgl/tile/geometry_tile_data.cpp
@@ -112,7 +112,7 @@ static Feature::geometry_type convertGeometry(const GeometryTileFeature& geometr
         );
     };
 
-    GeometryCollection geometries = geometryTileFeature.getGeometries();
+    const GeometryCollection& geometries = geometryTileFeature.getGeometries();
 
     switch (geometryTileFeature.getType()) {
         case FeatureType::Unknown: {
diff --git a/src/mbgl/tile/geometry_tile_data.hpp b/src/mbgl/tile/geometry_tile_data.hpp
index 6ce67a532e..db3378a019 100644
--- a/src/mbgl/tile/geometry_tile_data.hpp
+++ b/src/mbgl/tile/geometry_tile_data.hpp
@@ -44,7 +44,7 @@ public:
     virtual optional<Value> getValue(const std::string& key) const = 0;
     virtual PropertyMap getProperties() const { return PropertyMap(); }
     virtual FeatureIdentifier getID() const { return NullValue {}; }
-    virtual GeometryCollection getGeometries() const = 0;
+    virtual const GeometryCollection& getGeometries() const = 0;
 };
 
 class GeometryTileLayer {
diff --git a/src/mbgl/tile/vector_tile_data.cpp b/src/mbgl/tile/vector_tile_data.cpp
index 2d47515e0f..926e596080 100644
--- a/src/mbgl/tile/vector_tile_data.cpp
+++ b/src/mbgl/tile/vector_tile_data.cpp
@@ -34,14 +34,15 @@ FeatureIdentifier VectorTileFeature::getID() const {
     return feature.getID();
 }
 
-GeometryCollection VectorTileFeature::getGeometries() const {
-    const float scale = float(util::EXTENT) / feature.getExtent();
-    auto lines = feature.getGeometries<GeometryCollection>(scale);
-    if (feature.getVersion() >= 2 || feature.getType() != mapbox::vector_tile::GeomType::POLYGON) {
-        return lines;
-    } else {
-        return fixupPolygons(lines);
+const GeometryCollection& VectorTileFeature::getGeometries() const {
+    if (!lines) {
+        const float scale = float(util::EXTENT) / feature.getExtent();
+        lines = feature.getGeometries<GeometryCollection>(scale);
+        if (feature.getVersion() < 2 && feature.getType() == mapbox::vector_tile::GeomType::POLYGON) {
+            lines = fixupPolygons(*lines);
+        }
     }
+    return *lines;
 }
 
 VectorTileLayer::VectorTileLayer(std::shared_ptr<const std::string> data_,
diff --git a/src/mbgl/tile/vector_tile_data.hpp b/src/mbgl/tile/vector_tile_data.hpp
index 7c95121a37..525c7935e4 100644
--- a/src/mbgl/tile/vector_tile_data.hpp
+++ b/src/mbgl/tile/vector_tile_data.hpp
@@ -17,10 +17,11 @@ public:
     optional<Value> getValue(const std::string& key) const override;
     std::unordered_map<std::string, Value> getProperties() const override;
     FeatureIdentifier getID() const override;
-    GeometryCollection getGeometries() const override;
+    const GeometryCollection& getGeometries() const override;
 
 private:
     mapbox::vector_tile::feature feature;
+    mutable optional<GeometryCollection> lines;
 };
 
 class VectorTileLayer : public GeometryTileLayer {
diff --git a/test/src/mbgl/test/stub_geometry_tile_feature.hpp b/test/src/mbgl/test/stub_geometry_tile_feature.hpp
index ef21f8e937..e74988df2e 100644
--- a/test/src/mbgl/test/stub_geometry_tile_feature.hpp
+++ b/test/src/mbgl/test/stub_geometry_tile_feature.hpp
@@ -33,7 +33,7 @@ public:
         return properties.count(key) ? properties.at(key) : optional<Value>();
     }
 
-    GeometryCollection getGeometries() const override {
+    const GeometryCollection& getGeometries() const override {
         return geometry;
     }
 };