[core] shared data among AnnotationTileFeature objects

src/mbgl/annotation/annotation_manager.cpp

@@ -133,7 +133,7 @@ std::unique_ptr<AnnotationTileData> AnnotationManager::getTileData(const Canonic
 
     auto tileData = std::make_unique<AnnotationTileData>();
 
-    AnnotationTileLayer& pointLayer = tileData->layers.emplace(PointLayerID, PointLayerID).first->second;
+    AnnotationTileLayer& pointLayer = tileData->addLayer(PointLayerID);
 
     LatLngBounds tileBounds(tileID);
 

src/mbgl/annotation/annotation_tile.cpp

@@ -19,26 +19,64 @@ AnnotationTile::~AnnotationTile() {
     annotationManager.removeTile(*this);
 }
 
-void AnnotationTile::setNecessity(Necessity) {}
+void AnnotationTile::setNecessity(Necessity) {
+}
 
-AnnotationTileFeature::AnnotationTileFeature(const AnnotationID id_,
-                                             FeatureType type_, GeometryCollection geometries_,
-                                             std::unordered_map<std::string, std::string> properties_)
-    : id(id_),
-      type(type_),
-      properties(std::move(properties_)),
-      geometries(std::move(geometries_)) {}
+class AnnotationTileFeatureData {
+public:
+    AnnotationTileFeatureData(const AnnotationID id_,
+                              FeatureType type_,
+                              GeometryCollection&& geometries_,
+                              std::unordered_map<std::string, std::string>&& properties_)
+        : id(id_),
+          type(type_),
+          geometries(std::move(geometries_)),
+          properties(std::move(properties_)) {
+    }
+
+    AnnotationID id;
+    FeatureType type;
+    GeometryCollection geometries;
+    std::unordered_map<std::string, std::string> properties;
+};
+
+AnnotationTileFeature::AnnotationTileFeature(std::shared_ptr<const AnnotationTileFeatureData> data_)
+    : data(std::move(data_)) {
+}
+
+AnnotationTileFeature::~AnnotationTileFeature() = default;
+
+FeatureType AnnotationTileFeature::getType() const {
+    return data->type;
+}
 
 optional<Value> AnnotationTileFeature::getValue(const std::string& key) const {
-    auto it = properties.find(key);
-    if (it != properties.end()) {
+    auto it = data->properties.find(key);
+    if (it != data->properties.end()) {
         return optional<Value>(it->second);
     }
     return optional<Value>();
 }
 
-AnnotationTileLayer::AnnotationTileLayer(std::string name_)
-    : name(std::move(name_)) {}
+optional<FeatureIdentifier> AnnotationTileFeature::getID() const {
+    return { static_cast<uint64_t>(data->id) };
+}
+
+GeometryCollection AnnotationTileFeature::getGeometries() const {
+    return data->geometries;
+}
+
+AnnotationTileLayer::AnnotationTileLayer(std::string name_) : name(std::move(name_)) {
+}
+
+void AnnotationTileLayer::addFeature(const AnnotationID id,
+                                     FeatureType type,
+                                     GeometryCollection geometries,
+                                     std::unordered_map<std::string, std::string> properties) {
+
+    features.emplace_back(std::make_shared<AnnotationTileFeatureData>(
+        id, type, std::move(geometries), std::move(properties)));
+}
 
 std::unique_ptr<GeometryTileData> AnnotationTileData::clone() const {
     return std::make_unique<AnnotationTileData>(*this);
@@ -52,4 +90,9 @@ const GeometryTileLayer* AnnotationTileData::getLayer(const std::string& name) c
     return nullptr;
 }
 
+AnnotationTileLayer& AnnotationTileData::addLayer(const std::string& name) {
+    // Only constructs a new layer if it doesn't yet exist, otherwise, we'll use the existing one.
+    return layers.emplace(name, name).first->second;
+}
+
 } // namespace mbgl

src/mbgl/annotation/annotation_tile.hpp

@@ -11,8 +11,7 @@ class TileParameters;
 
 class AnnotationTile : public GeometryTile {
 public:
-    AnnotationTile(const OverscaledTileID&,
-                   const TileParameters&);
+    AnnotationTile(const OverscaledTileID&, const TileParameters&);
     ~AnnotationTile() override;
 
     void setNecessity(Necessity) final;
@@ -21,37 +20,45 @@ private:
     AnnotationManager& annotationManager;
 };
 
+class AnnotationTileFeatureData;
+
 class AnnotationTileFeature : public GeometryTileFeature {
 public:
-    AnnotationTileFeature(AnnotationID, FeatureType, GeometryCollection,
-                          std::unordered_map<std::string, std::string> properties = {{}});
+    AnnotationTileFeature(std::shared_ptr<const AnnotationTileFeatureData>);
+    ~AnnotationTileFeature() override;
 
-    FeatureType getType() const override { return type; }
+    FeatureType getType() const override;
     optional<Value> getValue(const std::string&) const override;
-    optional<FeatureIdentifier> getID() const override { return { static_cast<uint64_t>(id) }; }
-    GeometryCollection getGeometries() const override { return geometries; }
+    optional<FeatureIdentifier> getID() const override;
+    GeometryCollection getGeometries() const override;
 
-    const AnnotationID id;
-    const FeatureType type;
-    const std::unordered_map<std::string, std::string> properties;
-    const GeometryCollection geometries;
+private:
+    std::shared_ptr<const AnnotationTileFeatureData> data;
 };
 
 class AnnotationTileLayer : public GeometryTileLayer {
 public:
     AnnotationTileLayer(std::string);
 
-    std::size_t featureCount() const override { return features.size(); }
+    std::size_t featureCount() const override {
+        return features.size();
+    }
 
     std::unique_ptr<GeometryTileFeature> getFeature(std::size_t i) const override {
         return std::make_unique<AnnotationTileFeature>(features.at(i));
     }
 
-    std::string getName() const override { return name; };
+    std::string getName() const override {
+        return name;
+    }
 
-    std::vector<AnnotationTileFeature> features;
+    void addFeature(const AnnotationID,
+                    FeatureType,
+                    GeometryCollection,
+                    std::unordered_map<std::string, std::string> properties = { {} });
 
 private:
+    std::vector<std::shared_ptr<const AnnotationTileFeatureData>> features;
     std::string name;
 };
 
@@ -59,7 +66,9 @@ class AnnotationTileData : public GeometryTileData {
 public:
     std::unique_ptr<GeometryTileData> clone() const override;
     const GeometryTileLayer* getLayer(const std::string&) const override;
+    AnnotationTileLayer& addLayer(const std::string&);
 
+private:
     std::unordered_map<std::string, AnnotationTileLayer> layers;
 };
 

src/mbgl/annotation/shape_annotation_impl.cpp

@@ -38,7 +38,7 @@ void ShapeAnnotationImpl::updateTileData(const CanonicalTileID& tileID, Annotati
     if (shapeTile.features.empty())
         return;
 
-    AnnotationTileLayer& layer = data.layers.emplace(layerID, layerID).first->second;
+    AnnotationTileLayer& layer = data.addLayer(layerID);
 
     ToGeometryCollection toGeometryCollection;
     ToFeatureType toFeatureType;
@@ -53,7 +53,7 @@ void ShapeAnnotationImpl::updateTileData(const CanonicalTileID& tileID, Annotati
             renderGeometry = fixupPolygons(renderGeometry);
         }
 
-        layer.features.emplace_back(id, featureType, renderGeometry);
+        layer.addFeature(id, featureType, renderGeometry);
     }
 }
 

src/mbgl/annotation/symbol_annotation_impl.cpp

@@ -18,7 +18,7 @@ void SymbolAnnotationImpl::updateLayer(const CanonicalTileID& tileID, Annotation
     LatLng latLng { annotation.geometry.y, annotation.geometry.x };
     TileCoordinate coordinate = TileCoordinate::fromLatLng(0, latLng);
     GeometryCoordinate tilePoint = TileCoordinate::toGeometryCoordinate(UnwrappedTileID(0, tileID), coordinate.p);
-    layer.features.emplace_back(id, FeatureType::Point, GeometryCollection {{ {{ tilePoint }} }}, featureProperties);
+    layer.addFeature(id, FeatureType::Point, GeometryCollection {{ {{ tilePoint }} }}, featureProperties);
 }
 
 } // namespace mbgl