[core] Make FeatureIndex own GeometryTileData.

Prevents querying a FeatureIndex built against a separate set of data, which can lead to invalid index exceptions.
The GeometryTileWorker 'data' member can still change independently of the data in the feature index, at the time 'setData' is called. The GeometryTileWorker maintains ownership of its local data (which may be used to re-parse) and clones the data for use by the FeatureIndex in the foreground.

3 files changed, 13 insertions, 20 deletions

diff --git a/src/mbgl/tile/geometry_tile.cpp b/src/mbgl/tile/geometry_tile.cpp
index 5089f95022..a99cb91d26 100644
--- a/src/mbgl/tile/geometry_tile.cpp
+++ b/src/mbgl/tile/geometry_tile.cpp
@@ -133,7 +133,7 @@ void GeometryTile::onLayout(LayoutResult result, const uint64_t resultCorrelatio
     
     buckets = std::move(result.buckets);
     
-    dataPendingCommit = {{ std::move(result.tileData), std::move(result.featureIndex) }};
+    featureIndexPendingCommit = { std::move(result.featureIndex) };
 
     if (result.glyphAtlasImage) {
         glyphAtlasImage = std::move(*result.glyphAtlasImage);
@@ -202,12 +202,11 @@ Bucket* GeometryTile::getBucket(const Layer::Impl& layer) const {
 }
 
 void GeometryTile::commitFeatureIndex() {
-    // We commit our pending FeatureIndex and GeometryTileData when a global placement has run,
-    // synchronizing the global CollisionIndex with the latest buckets/FeatureIndex/GeometryTileData
-    if (dataPendingCommit) {
-        data = std::move(dataPendingCommit->first);
-        featureIndex = std::move(dataPendingCommit->second);
-        dataPendingCommit = nullopt;
+    // We commit our pending FeatureIndex when a global placement has run,
+    // synchronizing the global CollisionIndex with the latest buckets/FeatureIndex
+    if (featureIndexPendingCommit) {
+        featureIndex = std::move(*featureIndexPendingCommit);
+        featureIndexPendingCommit = nullopt;
     }
 }
 
@@ -219,7 +218,7 @@ void GeometryTile::queryRenderedFeatures(
     const RenderedQueryOptions& options,
     const CollisionIndex& collisionIndex) {
 
-    if (!featureIndex || !data) return;
+    if (!getData()) return;
 
     // Determine the additional radius needed factoring in property functions
     float additionalRadius = 0;
@@ -236,7 +235,6 @@ void GeometryTile::queryRenderedFeatures(
                         util::tileSize * id.overscaleFactor(),
                         std::pow(2, transformState.getZoom() - id.overscaledZ),
                         options,
-                        *data,
                         id.toUnwrapped(),
                         sourceID,
                         layers,
@@ -248,8 +246,8 @@ void GeometryTile::querySourceFeatures(
     std::vector<Feature>& result,
     const SourceQueryOptions& options) {
 
-    // Data not yet available
-    if (!data) {
+    // Data not yet available, or tile is empty
+    if (!getData()) {
         return;
     }
     
@@ -262,7 +260,7 @@ void GeometryTile::querySourceFeatures(
     for (auto sourceLayer : *options.sourceLayers) {
         // Go throught all sourceLayers, if any
         // to gather all the features
-        auto layer = data->getLayer(sourceLayer);
+        auto layer = getData()->getLayer(sourceLayer);
         
         if (layer) {
             auto featureCount = layer->featureCount();
diff --git a/src/mbgl/tile/geometry_tile.hpp b/src/mbgl/tile/geometry_tile.hpp
index 0161e00efd..418db4a0b2 100644
--- a/src/mbgl/tile/geometry_tile.hpp
+++ b/src/mbgl/tile/geometry_tile.hpp
@@ -67,18 +67,15 @@ public:
     public:
         std::unordered_map<std::string, std::shared_ptr<Bucket>> buckets;
         std::unique_ptr<FeatureIndex> featureIndex;
-        std::unique_ptr<GeometryTileData> tileData;
         optional<AlphaImage> glyphAtlasImage;
         optional<PremultipliedImage> iconAtlasImage;
 
         LayoutResult(std::unordered_map<std::string, std::shared_ptr<Bucket>> buckets_,
                      std::unique_ptr<FeatureIndex> featureIndex_,
-                     std::unique_ptr<GeometryTileData> tileData_,
                      optional<AlphaImage> glyphAtlasImage_,
                      optional<PremultipliedImage> iconAtlasImage_)
             : buckets(std::move(buckets_)),
               featureIndex(std::move(featureIndex_)),
-              tileData(std::move(tileData_)),
               glyphAtlasImage(std::move(glyphAtlasImage_)),
               iconAtlasImage(std::move(iconAtlasImage_)) {}
     };
@@ -95,7 +92,7 @@ public:
     
 protected:
     const GeometryTileData* getData() {
-        return data.get();
+        return featureIndex ? featureIndex->getData() : nullptr;
     }
 
 private:
@@ -116,9 +113,8 @@ private:
 
     std::unordered_map<std::string, std::shared_ptr<Bucket>> buckets;
     
-    optional<std::pair<std::unique_ptr<const GeometryTileData>, std::unique_ptr<FeatureIndex>>> dataPendingCommit;
+    optional<std::unique_ptr<FeatureIndex>> featureIndexPendingCommit;
     std::unique_ptr<FeatureIndex> featureIndex;
-    std::unique_ptr<const GeometryTileData> data;
 
     optional<AlphaImage> glyphAtlasImage;
     optional<PremultipliedImage> iconAtlasImage;
diff --git a/src/mbgl/tile/geometry_tile_worker.cpp b/src/mbgl/tile/geometry_tile_worker.cpp
index f57732117b..1378ad5d3a 100644
--- a/src/mbgl/tile/geometry_tile_worker.cpp
+++ b/src/mbgl/tile/geometry_tile_worker.cpp
@@ -329,7 +329,7 @@ void GeometryTileWorker::parse() {
 
     std::unordered_map<std::string, std::unique_ptr<SymbolLayout>> symbolLayoutMap;
     buckets.clear();
-    featureIndex = std::make_unique<FeatureIndex>();
+    featureIndex = std::make_unique<FeatureIndex>(*data ? (*data)->clone() : nullptr);
     BucketParameters parameters { id, mode, pixelRatio };
 
     GlyphDependencies glyphDependencies;
@@ -471,7 +471,6 @@ void GeometryTileWorker::performSymbolLayout() {
     parent.invoke(&GeometryTile::onLayout, GeometryTile::LayoutResult {
         std::move(buckets),
         std::move(featureIndex),
-        *data ? (*data)->clone() : nullptr,
         std::move(glyphAtlasImage),
         std::move(iconAtlasImage)
     }, correlationID);