[core] Virtualize Source::load

8 files changed, 132 insertions, 99 deletions

diff --git a/src/mbgl/annotation/annotation_source.cpp b/src/mbgl/annotation/annotation_source.cpp
index 50fa7a2c09..aa52e2e434 100644
--- a/src/mbgl/annotation/annotation_source.cpp
+++ b/src/mbgl/annotation/annotation_source.cpp
@@ -8,6 +8,10 @@ AnnotationSource::AnnotationSource()
     : Source(SourceType::Annotations, AnnotationManager::SourceID, "", util::tileSize, std::make_unique<Tileset>()) {
 }
 
+void AnnotationSource::load(FileSource&) {
+    loaded = true;
+}
+
 std::unique_ptr<Tile> AnnotationSource::createTile(const OverscaledTileID& tileID,
                                                    const style::UpdateParameters& parameters) {
     return std::make_unique<AnnotationTile>(tileID, id, parameters);
diff --git a/src/mbgl/annotation/annotation_source.hpp b/src/mbgl/annotation/annotation_source.hpp
index 033580b645..565b9273d6 100644
--- a/src/mbgl/annotation/annotation_source.hpp
+++ b/src/mbgl/annotation/annotation_source.hpp
@@ -8,6 +8,8 @@ class AnnotationSource : public style::Source {
 public:
     AnnotationSource();
 
+    void load(FileSource&) final;
+
 private:
     std::unique_ptr<Tile> createTile(const OverscaledTileID&, const style::UpdateParameters&) final;
 };
diff --git a/src/mbgl/style/source.cpp b/src/mbgl/style/source.cpp
index 35acf3dd51..41c1d0d22b 100644
--- a/src/mbgl/style/source.cpp
+++ b/src/mbgl/style/source.cpp
@@ -7,7 +7,6 @@
 #include <mbgl/util/constants.hpp>
 #include <mbgl/storage/resource.hpp>
 #include <mbgl/storage/response.hpp>
-#include <mbgl/storage/file_source.hpp>
 #include <mbgl/style/layer.hpp>
 #include <mbgl/style/update_parameters.hpp>
 #include <mbgl/style/query_parameters.hpp>
@@ -20,7 +19,6 @@
 #include <mbgl/util/tile_cover.hpp>
 #include <mbgl/util/enum.hpp>
 
-#include <mbgl/style/parser.hpp>
 #include <mbgl/gl/debugging.hpp>
 
 #include <mbgl/algorithm/update_renderables.hpp>
@@ -29,10 +27,7 @@
 #include <mapbox/geojsonvt/convert.hpp>
 #include <mapbox/geometry/envelope.hpp>
 
-#include <rapidjson/error/en.h>
-
 #include <algorithm>
-#include <sstream>
 
 namespace mbgl {
 namespace style {
@@ -70,95 +65,10 @@ bool Source::isLoading() const {
     return !loaded && req.operator bool();
 }
 
-void Source::load(FileSource& fileSource) {
-    if (url.empty()) {
-        // In case there is no URL set, we assume that we already have all of the data because the
-        // TileJSON was specified inline in the stylesheet.
-        loaded = true;
-        return;
-    }
-
-    if (req) {
-        // We don't have a Tileset object yet, but there's already a request underway to load
-        // the data.
-        return;
-    }
-
-    // URL may either be a TileJSON file, or a GeoJSON file.
-    req = fileSource.request(Resource::source(url), [this](Response res) {
-        if (res.error) {
-            observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error(res.error->message)));
-        } else if (res.notModified) {
-            return;
-        } else if (res.noContent) {
-            observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error("unexpectedly empty source")));
-        } else {
-            bool reloadTiles = false;
-
-            if (type == SourceType::Vector || type == SourceType::Raster) {
-                std::unique_ptr<Tileset> newTileset;
-
-                // Create a new copy of the Tileset object that holds the base values we've parsed
-                // from the stylesheet. Then merge in the values parsed from the TileJSON we retrieved
-                // via the URL.
-                try {
-                    newTileset = style::parseTileJSON(*res.data, url, type, tileSize);
-                } catch (...) {
-                    observer->onSourceError(*this, std::current_exception());
-                    return;
-                }
-
-                // Check whether previous information specifies different tile
-                if (tileset && tileset->tiles != newTileset->tiles) {
-                    reloadTiles = true;
-
-                    // Tile size changed: We need to recalculate the tiles we need to load because we
-                    // might have to load tiles for a different zoom level
-                    // This is done automatically when we trigger the onSourceLoaded observer below.
-
-                    // Min/Max zoom changed: We need to recalculate what tiles to load, if we have tiles
-                    // loaded that are outside the new zoom range
-                    // This is done automatically when we trigger the onSourceLoaded observer below.
-
-                    // Attribution changed: We need to notify the embedding application that this
-                    // changed. See https://github.com/mapbox/mapbox-gl-native/issues/2723
-                    // This is not yet implemented.
-
-                    // Center/bounds changed: We're not using these values currently
-                }
-
-                tileset = std::move(newTileset);
-            } else if (type == SourceType::GeoJSON) {
-                std::unique_ptr<Tileset> newTileset = std::make_unique<Tileset>();
-
-                rapidjson::GenericDocument<rapidjson::UTF8<>, rapidjson::CrtAllocator> d;
-                d.Parse<0>(res.data->c_str());
-
-                if (d.HasParseError()) {
-                    std::stringstream message;
-                    message << d.GetErrorOffset() << " - " << rapidjson::GetParseError_En(d.GetParseError());
-                    observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error(message.str())));
-                    return;
-                }
-
-                geojsonvt = style::parseGeoJSON(d);
-                reloadTiles = true;
-
-                newTileset->maxZoom = geojsonvt->options.maxZoom;
-                tileset = std::move(newTileset);
-            }
-
-            if (reloadTiles) {
-                // Tile information changed because we got new GeoJSON data, or a new tile URL.
-                tiles.clear();
-                renderTiles.clear();
-                cache.clear();
-            }
-
-            loaded = true;
-            observer->onSourceLoaded(*this);
-        }
-    });
+void Source::invalidateTiles() {
+    tiles.clear();
+    renderTiles.clear();
+    cache.clear();
 }
 
 void Source::updateMatrices(const mat4 &projMatrix, const TransformState &transform) {
diff --git a/src/mbgl/style/source.hpp b/src/mbgl/style/source.hpp
index 51a9ba5c71..92ca808afb 100644
--- a/src/mbgl/style/source.hpp
+++ b/src/mbgl/style/source.hpp
@@ -48,7 +48,7 @@ public:
     ~Source() override;
 
     bool loaded = false;
-    void load(FileSource&);
+    virtual void load(FileSource&) = 0;
     bool isLoading() const;
     bool isLoaded() const;
 
@@ -96,8 +96,13 @@ private:
     virtual std::unique_ptr<Tile> createTile(const OverscaledTileID&, const UpdateParameters&) = 0;
 
 protected:
+    void invalidateTiles();
+
     std::unique_ptr<const Tileset> tileset;
     std::unique_ptr<mapbox::geojsonvt::GeoJSONVT> geojsonvt;
+    std::unique_ptr<AsyncRequest> req;
+
+    SourceObserver* observer = nullptr;
 
 private:
     // Stores the time when this source was most recently updated.
@@ -106,10 +111,6 @@ private:
     std::map<OverscaledTileID, std::unique_ptr<Tile>> tiles;
     std::map<UnwrappedTileID, RenderTile> renderTiles;
     TileCache cache;
-
-    std::unique_ptr<AsyncRequest> req;
-
-    SourceObserver* observer = nullptr;
 };
 
 } // namespace style
diff --git a/src/mbgl/style/sources/geojson_source.cpp b/src/mbgl/style/sources/geojson_source.cpp
index caedcffcd5..6ece894e2e 100644
--- a/src/mbgl/style/sources/geojson_source.cpp
+++ b/src/mbgl/style/sources/geojson_source.cpp
@@ -1,8 +1,15 @@
 #include <mbgl/style/sources/geojson_source.hpp>
+#include <mbgl/style/source_observer.hpp>
+#include <mbgl/style/parser.hpp>
 #include <mbgl/tile/geojson_tile.hpp>
+#include <mbgl/storage/file_source.hpp>
 
 #include <mapbox/geojsonvt.hpp>
 
+#include <rapidjson/error/en.h>
+
+#include <sstream>
+
 namespace mbgl {
 namespace style {
 
@@ -15,6 +22,49 @@ GeoJSONSource::GeoJSONSource(std::string id_,
     geojsonvt = std::move(geojsonvt_);
 }
 
+void GeoJSONSource::load(FileSource& fileSource) {
+    if (url.empty()) {
+        // If the URL is empty, the GeoJSON was specified inline in the stylesheet.
+        loaded = true;
+        return;
+    }
+
+    if (req) {
+        return;
+    }
+
+    req = fileSource.request(Resource::source(url), [this](Response res) {
+        if (res.error) {
+            observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error(res.error->message)));
+        } else if (res.notModified) {
+            return;
+        } else if (res.noContent) {
+            observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error("unexpectedly empty GeoJSON")));
+        } else {
+            std::unique_ptr<Tileset> newTileset = std::make_unique<Tileset>();
+
+            rapidjson::GenericDocument<rapidjson::UTF8<>, rapidjson::CrtAllocator> d;
+            d.Parse<0>(res.data->c_str());
+
+            if (d.HasParseError()) {
+                std::stringstream message;
+                message << d.GetErrorOffset() << " - " << rapidjson::GetParseError_En(d.GetParseError());
+                observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error(message.str())));
+                return;
+            }
+
+            geojsonvt = style::parseGeoJSON(d);
+            newTileset->maxZoom = geojsonvt->options.maxZoom;
+
+            invalidateTiles();
+
+            tileset = std::move(newTileset);
+            loaded = true;
+            observer->onSourceLoaded(*this);
+        }
+    });
+}
+
 std::unique_ptr<Tile> GeoJSONSource::createTile(const OverscaledTileID& tileID,
                                                 const UpdateParameters& parameters) {
     return std::make_unique<GeoJSONTile>(tileID, id, parameters, geojsonvt.get());
diff --git a/src/mbgl/style/sources/geojson_source.hpp b/src/mbgl/style/sources/geojson_source.hpp
index c9262f22b7..47984ff9da 100644
--- a/src/mbgl/style/sources/geojson_source.hpp
+++ b/src/mbgl/style/sources/geojson_source.hpp
@@ -13,6 +13,8 @@ public:
                   std::unique_ptr<Tileset>&&,
                   std::unique_ptr<mapbox::geojsonvt::GeoJSONVT>&&);
 
+    void load(FileSource&) final;
+
 private:
     std::unique_ptr<Tile> createTile(const OverscaledTileID&, const UpdateParameters&) final;
 };
diff --git a/src/mbgl/style/tile_source.cpp b/src/mbgl/style/tile_source.cpp
index 22739035a9..90f4b54d96 100644
--- a/src/mbgl/style/tile_source.cpp
+++ b/src/mbgl/style/tile_source.cpp
@@ -1,4 +1,7 @@
 #include <mbgl/style/tile_source.hpp>
+#include <mbgl/style/source_observer.hpp>
+#include <mbgl/style/parser.hpp>
+#include <mbgl/storage/file_source.hpp>
 
 namespace mbgl {
 namespace style {
@@ -11,5 +14,64 @@ TileSource::TileSource(SourceType type_,
     : Source(type_, std::move(id_), std::move(url_), tileSize_, std::move(tileset_)) {
 }
 
+void TileSource::load(FileSource& fileSource) {
+    if (url.empty()) {
+        // If the URL is empty, the TileJSON was specified inline in the stylesheet.
+        loaded = true;
+        return;
+    }
+
+    if (req) {
+        return;
+    }
+
+    // URL may either be a TileJSON file, or a GeoJSON file.
+    req = fileSource.request(Resource::source(url), [this](Response res) {
+        if (res.error) {
+            observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error(res.error->message)));
+        } else if (res.notModified) {
+            return;
+        } else if (res.noContent) {
+            observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error("unexpectedly empty TileJSON")));
+        } else {
+            std::unique_ptr<Tileset> newTileset;
+
+            // Create a new copy of the Tileset object that holds the base values we've parsed
+            // from the stylesheet. Then merge in the values parsed from the TileJSON we retrieved
+            // via the URL.
+            try {
+                newTileset = style::parseTileJSON(*res.data, url, type, tileSize);
+            } catch (...) {
+                observer->onSourceError(*this, std::current_exception());
+                return;
+            }
+
+            // Check whether previous information specifies different tile
+            if (tileset && tileset->tiles != newTileset->tiles) {
+                // Tile URLs changed: force tiles to be reloaded.
+                invalidateTiles();
+
+                // Tile size changed: We need to recalculate the tiles we need to load because we
+                // might have to load tiles for a different zoom level
+                // This is done automatically when we trigger the onSourceLoaded observer below.
+
+                // Min/Max zoom changed: We need to recalculate what tiles to load, if we have tiles
+                // loaded that are outside the new zoom range
+                // This is done automatically when we trigger the onSourceLoaded observer below.
+
+                // Attribution changed: We need to notify the embedding application that this
+                // changed. See https://github.com/mapbox/mapbox-gl-native/issues/2723
+                // This is not yet implemented.
+
+                // Center/bounds changed: We're not using these values currently
+            }
+
+            tileset = std::move(newTileset);
+            loaded = true;
+            observer->onSourceLoaded(*this);
+        }
+    });
+}
+
 } // namespace style
 } // namespace mbgl
diff --git a/src/mbgl/style/tile_source.hpp b/src/mbgl/style/tile_source.hpp
index 8c69ad451f..dc48080ea0 100644
--- a/src/mbgl/style/tile_source.hpp
+++ b/src/mbgl/style/tile_source.hpp
@@ -16,6 +16,8 @@ public:
                std::string url,
                uint16_t tileSize,
                std::unique_ptr<Tileset>&&);
+
+    void load(FileSource&) final;
 };
 
 } // namespace style