[core] Use an actor model for tile worker concurrency

1 files changed, 76 insertions, 0 deletions

diff --git a/src/mbgl/tile/geometry_tile_worker.hpp b/src/mbgl/tile/geometry_tile_worker.hpp
new file mode 100644
index 0000000000..cc5e48f9b4
--- /dev/null
+++ b/src/mbgl/tile/geometry_tile_worker.hpp
@@ -0,0 +1,76 @@
+#pragma once
+
+#include <mbgl/map/mode.hpp>
+#include <mbgl/tile/tile_id.hpp>
+#include <mbgl/text/placement_config.hpp>
+#include <mbgl/actor/actor_ref.hpp>
+#include <mbgl/util/optional.hpp>
+
+#include <atomic>
+#include <memory>
+#include <unordered_map>
+
+namespace mbgl {
+
+class GeometryTile;
+class GeometryTileData;
+class SpriteStore;
+class GlyphAtlas;
+class GlyphStore;
+class SymbolLayout;
+
+namespace style {
+class Layer;
+} // namespace style
+
+class GeometryTileWorker {
+public:
+    GeometryTileWorker(ActorRef<GeometryTileWorker> self,
+                       ActorRef<GeometryTile> parent,
+                       OverscaledTileID,
+                       SpriteStore&,
+                       GlyphAtlas&,
+                       GlyphStore&,
+                       const std::atomic<bool>&,
+                       const MapMode);
+    ~GeometryTileWorker();
+
+    void setLayers(std::vector<std::unique_ptr<style::Layer>>, uint64_t correlationID);
+    void setData(std::unique_ptr<const GeometryTileData>, uint64_t correlationID);
+    void setPlacementConfig(PlacementConfig, uint64_t correlationID);
+
+private:
+    void coalesce();
+    void coalesced();
+    void redoLayout();
+    void attemptPlacement();
+
+    ActorRef<GeometryTileWorker> self;
+    ActorRef<GeometryTile> parent;
+
+    const OverscaledTileID id;
+    SpriteStore& spriteStore;
+    GlyphAtlas& glyphAtlas;
+    GlyphStore& glyphStore;
+    const std::atomic<bool>& obsolete;
+    const MapMode mode;
+
+    enum State {
+        Idle,
+        Coalescing,
+        NeedLayout,
+        NeedPlacement
+    };
+
+    State state = Idle;
+    uint64_t correlationID = 0;
+
+    // Outer optional indicates whether we've received it or not.
+    optional<std::vector<std::unique_ptr<style::Layer>>> layers;
+    optional<std::unique_ptr<const GeometryTileData>> data;
+    optional<PlacementConfig> placementConfig;
+
+    std::vector<std::unique_ptr<SymbolLayout>> symbolLayouts;
+};
+
+} // namespace mbgl