From 8e2170c8855456258de8ffd49d22a621b95e9fb2 Mon Sep 17 00:00:00 2001
From: John Firebaugh <john.firebaugh@gmail.com>
Date: Tue, 30 Aug 2016 12:43:46 -0700
Subject: [core] Batch source updates

---
 include/mbgl/map/update.hpp     |  5 ++---
 src/mbgl/map/map.cpp            |  4 ++++
 src/mbgl/style/style.cpp        | 35 ++++++++++++++++++++++-------------
 src/mbgl/style/style.hpp        |  3 +++
 src/mbgl/style/update_batch.hpp | 15 +++++++++++++++
 5 files changed, 46 insertions(+), 16 deletions(-)
 create mode 100644 src/mbgl/style/update_batch.hpp

diff --git a/include/mbgl/map/update.hpp b/include/mbgl/map/update.hpp
index 36ce59c01d..1da7e3ac92 100644
--- a/include/mbgl/map/update.hpp
+++ b/include/mbgl/map/update.hpp
@@ -2,11 +2,9 @@
 
 #include <mbgl/util/traits.hpp>
 
-#include <cstdint>
-
 namespace mbgl {
 
-enum class Update : uint8_t {
+enum class Update {
     Nothing                   = 0,
     Dimensions                = 1 << 1,
     Classes                   = 1 << 2,
@@ -15,6 +13,7 @@ enum class Update : uint8_t {
     Repaint                   = 1 << 5,
     AnnotationStyle           = 1 << 6,
     AnnotationData            = 1 << 7,
+    Layout                    = 1 << 8
 };
 
 constexpr Update operator|(Update lhs, Update rhs) {
diff --git a/src/mbgl/map/map.cpp b/src/mbgl/map/map.cpp
index fe0be15b87..9e18e67f3a 100644
--- a/src/mbgl/map/map.cpp
+++ b/src/mbgl/map/map.cpp
@@ -212,6 +212,10 @@ void Map::Impl::update() {
         annotationManager->updateData();
     }
 
+    if (updateFlags & Update::Layout) {
+        style->relayout();
+    }
+
     if (updateFlags & Update::Classes) {
         style->cascade(timePoint, mode);
     }
diff --git a/src/mbgl/style/style.cpp b/src/mbgl/style/style.cpp
index e797ec7a5b..1009654fc4 100644
--- a/src/mbgl/style/style.cpp
+++ b/src/mbgl/style/style.cpp
@@ -92,6 +92,7 @@ void Style::setJSON(const std::string& json) {
     sources.clear();
     layers.clear();
     classes.clear();
+    updateBatch = {};
 
     Parser parser;
     auto error = parser.parse(json);
@@ -133,9 +134,13 @@ void Style::removeSource(const std::string& id) {
     auto it = std::find_if(sources.begin(), sources.end(), [&](const auto& source) {
         return source->getID() == id;
     });
-    if (it == sources.end())
+
+    if (it == sources.end()) {
         throw std::runtime_error("no such source");
+    }
+
     sources.erase(it);
+    updateBatch.sourceIDs.erase(id);
 }
 
 std::vector<const Layer*> Style::getLayers() const {
@@ -220,6 +225,15 @@ void Style::updateTiles(const UpdateParameters& parameters) {
     }
 }
 
+void Style::relayout() {
+    for (const auto& sourceID : updateBatch.sourceIDs) {
+        Source* source = getSource(sourceID);
+        if (!source) continue;
+        source->baseImpl->reload();
+    }
+    updateBatch.sourceIDs.clear();
+}
+
 void Style::cascade(const TimePoint& timePoint, MapMode mode) {
     // When in continuous mode, we can either have user- or style-defined
     // transitions. Still mode is always immediate.
@@ -487,8 +501,8 @@ void Style::onSpriteError(std::exception_ptr error) {
     observer->onResourceError(error);
 }
 
-struct LayerSourceReloadVisitor {
-    Style& style;
+struct QueueSourceReloadVisitor {
+    UpdateBatch& updateBatch;
 
     void operator()(CustomLayer&) { assert(false); }
     void operator()(RasterLayer&) { assert(false); }
@@ -496,18 +510,13 @@ struct LayerSourceReloadVisitor {
 
     template <class VectorLayer>
     void operator()(VectorLayer& layer) {
-        Source* source = style.getSource(layer.getSourceID());
-        if (!source) return;
-        source->baseImpl->reload();
+        updateBatch.sourceIDs.insert(layer.getSourceID());
     }
 };
 
-void Style::reloadLayerSource(Layer& layer) {
-    layer.accept(LayerSourceReloadVisitor { *this });
-}
-
 void Style::onLayerFilterChanged(Layer& layer) {
-    reloadLayerSource(layer);
+    layer.accept(QueueSourceReloadVisitor { updateBatch });
+    observer->onUpdate(Update::Layout);
 }
 
 void Style::onLayerPaintPropertyChanged(Layer&) {
@@ -515,8 +524,8 @@ void Style::onLayerPaintPropertyChanged(Layer&) {
 }
 
 void Style::onLayerLayoutPropertyChanged(Layer& layer) {
-    observer->onUpdate(Update::RecalculateStyle);
-    reloadLayerSource(layer);
+    layer.accept(QueueSourceReloadVisitor { updateBatch });
+    observer->onUpdate(Update::Layout);
 }
 
 void Style::dumpDebugLogs() const {
diff --git a/src/mbgl/style/style.hpp b/src/mbgl/style/style.hpp
index 26b96fba22..b3f70e1eb2 100644
--- a/src/mbgl/style/style.hpp
+++ b/src/mbgl/style/style.hpp
@@ -4,6 +4,7 @@
 #include <mbgl/style/observer.hpp>
 #include <mbgl/style/source_observer.hpp>
 #include <mbgl/style/layer_observer.hpp>
+#include <mbgl/style/update_batch.hpp>
 #include <mbgl/text/glyph_store_observer.hpp>
 #include <mbgl/sprite/sprite_store_observer.hpp>
 #include <mbgl/map/mode.hpp>
@@ -52,6 +53,7 @@ public:
     // a tile is ready so observers can render the tile.
     void updateTiles(const UpdateParameters&);
 
+    void relayout();
     void cascade(const TimePoint&, MapMode);
     void recalculate(float z, const TimePoint&, MapMode);
 
@@ -142,6 +144,7 @@ private:
 
     std::exception_ptr lastError;
 
+    UpdateBatch updateBatch;
     ZoomHistory zoomHistory;
     bool hasPendingTransitions = false;
 
diff --git a/src/mbgl/style/update_batch.hpp b/src/mbgl/style/update_batch.hpp
new file mode 100644
index 0000000000..ee82c98fda
--- /dev/null
+++ b/src/mbgl/style/update_batch.hpp
@@ -0,0 +1,15 @@
+#pragma once
+
+#include <set>
+#include <string>
+
+namespace mbgl {
+namespace style {
+
+class UpdateBatch {
+public:
+    std::set<std::string> sourceIDs;
+};
+
+} // namespace style
+} // namespace mbgl
-- 
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