[core] Calculate GeoJSON tile geometries in a background thread

Call `mapbox::geojsonvt::GeoJSONVT::getTile()` in a background
thread, so that the rendering thread is not blocked.

2 files changed, 25 insertions, 9 deletions

diff --git a/src/mbgl/tile/geojson_tile.cpp b/src/mbgl/tile/geojson_tile.cpp
index 0782f74d5d..a4c48fb809 100644
--- a/src/mbgl/tile/geojson_tile.cpp
+++ b/src/mbgl/tile/geojson_tile.cpp
@@ -1,20 +1,29 @@
-#include <mbgl/tile/geojson_tile.hpp>
-#include <mbgl/tile/geojson_tile_data.hpp>
 #include <mbgl/renderer/query.hpp>
 #include <mbgl/renderer/tile_parameters.hpp>
-
+#include <mbgl/style/sources/geojson_source.hpp>
+#include <mbgl/tile/geojson_tile.hpp>
+#include <mbgl/tile/geojson_tile_data.hpp>
 namespace mbgl {
 
 GeoJSONTile::GeoJSONTile(const OverscaledTileID& overscaledTileID,
                          std::string sourceID_,
                          const TileParameters& parameters,
-                         mapbox::feature::feature_collection<int16_t> features)
+                         std::shared_ptr<style::GeoJSONData> data_)
     : GeometryTile(overscaledTileID, sourceID_, parameters) {
-    updateData(std::move(features));
+    updateData(std::move(data_));
 }
 
-void GeoJSONTile::updateData(mapbox::feature::feature_collection<int16_t> features, bool resetLayers) {
-    setData(std::make_unique<GeoJSONTileData>(std::move(features)), resetLayers);
+void GeoJSONTile::updateData(std::shared_ptr<style::GeoJSONData> data_, bool resetLayers) {
+    assert(data_);
+    data = std::move(data_);
+    data->getTile(id.canonical,
+                  [this, self = weakFactory.makeWeakPtr(), capturedData = data.get(), resetLayers](
+                      style::GeoJSONData::TileFeatures features) {
+                      if (!self) return;
+                      if (data.get() != capturedData) return;
+                      auto tileData = std::make_unique<GeoJSONTileData>(std::move(features));
+                      setData(std::move(tileData), resetLayers);
+                  });
 }
 
 void GeoJSONTile::querySourceFeatures(
diff --git a/src/mbgl/tile/geojson_tile.hpp b/src/mbgl/tile/geojson_tile.hpp
index 9161e33f0c..26dc300bdc 100644
--- a/src/mbgl/tile/geojson_tile.hpp
+++ b/src/mbgl/tile/geojson_tile.hpp
@@ -4,6 +4,9 @@
 #include <mbgl/util/feature.hpp>
 
 namespace mbgl {
+namespace style {
+class GeoJSONData;
+} // namespace style
 
 class TileParameters;
 
@@ -12,13 +15,17 @@ public:
     GeoJSONTile(const OverscaledTileID&,
                 std::string sourceID,
                 const TileParameters&,
-                mapbox::feature::feature_collection<int16_t>);
+                std::shared_ptr<style::GeoJSONData>);
 
-    void updateData(mapbox::feature::feature_collection<int16_t>, bool resetLayers = false);
+    void updateData(std::shared_ptr<style::GeoJSONData> data, bool resetLayers = false);
 
     void querySourceFeatures(
         std::vector<Feature>& result,
         const SourceQueryOptions&) override;
+
+private:
+    std::shared_ptr<style::GeoJSONData> data;
+    mapbox::base::WeakPtrFactory<GeoJSONTile> weakFactory{this};
 };
 
 } // namespace mbgl