Add config version, and invalidate layout on config change

tests/YGScaleChangeTest.cpp

@@ -0,0 +1,177 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <gtest/gtest.h>
+#include <yoga/Yoga.h>
+
+TEST(YogaTest, scale_change_invalidates_layout) {
+  const YGConfigRef config = YGConfigNew();
+
+  const YGNodeRef root = YGNodeNewWithConfig(config);
+  YGConfigSetPointScaleFactor(config, 1.0f);
+
+  YGNodeStyleSetFlexDirection(root, YGFlexDirectionRow);
+  YGNodeStyleSetWidth(root, 50);
+  YGNodeStyleSetHeight(root, 50);
+
+  const YGNodeRef root_child0 = YGNodeNewWithConfig(config);
+  YGNodeStyleSetFlexGrow(root_child0, 1);
+  YGNodeInsertChild(root, root_child0, 0);
+
+  const YGNodeRef root_child1 = YGNodeNewWithConfig(config);
+  YGNodeStyleSetFlexGrow(root_child1, 1);
+  YGNodeInsertChild(root, root_child1, 1);
+
+  YGNodeCalculateLayout(root, YGUndefined, YGUndefined, YGDirectionLTR);
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetLeft(root_child0));
+  ASSERT_FLOAT_EQ(25, YGNodeLayoutGetLeft(root_child1));
+
+  YGConfigSetPointScaleFactor(config, 1.5f);
+  YGNodeCalculateLayout(root, YGUndefined, YGUndefined, YGDirectionLTR);
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetLeft(root_child0));
+  // Left should change due to pixel alignment of new scale factor
+  ASSERT_FLOAT_EQ(25.333334f, YGNodeLayoutGetLeft(root_child1));
+
+  YGNodeFreeRecursive(root);
+  YGConfigFree(config);
+}
+
+TEST(YogaTest, errata_config_change_relayout) {
+  YGConfig* config = YGConfigNew();
+  YGConfigSetErrata(config, YGErrataStretchFlexBasis);
+  const YGNodeRef root = YGNodeNewWithConfig(config);
+  YGNodeStyleSetWidth(root, 500);
+  YGNodeStyleSetHeight(root, 500);
+
+  const YGNodeRef root_child0 = YGNodeNewWithConfig(config);
+  YGNodeStyleSetAlignItems(root_child0, YGAlignFlexStart);
+  YGNodeInsertChild(root, root_child0, 0);
+
+  const YGNodeRef root_child0_child0 = YGNodeNewWithConfig(config);
+  YGNodeStyleSetFlexGrow(root_child0_child0, 1);
+  YGNodeStyleSetFlexShrink(root_child0_child0, 1);
+  YGNodeInsertChild(root_child0, root_child0_child0, 0);
+
+  const YGNodeRef root_child0_child0_child0 = YGNodeNewWithConfig(config);
+  YGNodeStyleSetFlexGrow(root_child0_child0_child0, 1);
+  YGNodeStyleSetFlexShrink(root_child0_child0_child0, 1);
+  YGNodeInsertChild(root_child0_child0, root_child0_child0_child0, 0);
+  YGNodeCalculateLayout(root, YGUndefined, YGUndefined, YGDirectionLTR);
+
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetLeft(root));
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetTop(root));
+  ASSERT_FLOAT_EQ(500, YGNodeLayoutGetWidth(root));
+  ASSERT_FLOAT_EQ(500, YGNodeLayoutGetHeight(root));
+
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetLeft(root_child0));
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetTop(root_child0));
+  ASSERT_FLOAT_EQ(500, YGNodeLayoutGetWidth(root_child0));
+  ASSERT_FLOAT_EQ(500, YGNodeLayoutGetHeight(root_child0));
+
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetLeft(root_child0_child0));
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetTop(root_child0_child0));
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetWidth(root_child0_child0));
+  ASSERT_FLOAT_EQ(500, YGNodeLayoutGetHeight(root_child0_child0));
+
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetLeft(root_child0_child0_child0));
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetTop(root_child0_child0_child0));
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetWidth(root_child0_child0_child0));
+  ASSERT_FLOAT_EQ(500, YGNodeLayoutGetHeight(root_child0_child0_child0));
+
+  YGConfigSetErrata(config, YGErrataNone);
+  YGNodeCalculateLayout(root, YGUndefined, YGUndefined, YGDirectionLTR);
+
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetLeft(root));
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetTop(root));
+  ASSERT_FLOAT_EQ(500, YGNodeLayoutGetWidth(root));
+  ASSERT_FLOAT_EQ(500, YGNodeLayoutGetHeight(root));
+
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetLeft(root_child0));
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetTop(root_child0));
+  ASSERT_FLOAT_EQ(500, YGNodeLayoutGetWidth(root_child0));
+  // This should be modified by the lack of the errata
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetHeight(root_child0));
+
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetLeft(root_child0_child0));
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetTop(root_child0_child0));
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetWidth(root_child0_child0));
+  // This should be modified by the lack of the errata
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetHeight(root_child0_child0));
+
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetLeft(root_child0_child0_child0));
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetTop(root_child0_child0_child0));
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetWidth(root_child0_child0_child0));
+  // This should be modified by the lack of the errata
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetHeight(root_child0_child0_child0));
+
+  YGNodeFreeRecursive(root);
+
+  YGConfigFree(config);
+}
+
+static uint32_t _measureCallCount = 0;
+static YGSize _measureCustom(
+    YGNodeConstRef /*node*/,
+    float width,
+    YGMeasureMode /*widthMode*/,
+    float height,
+    YGMeasureMode /*heightMode*/) {
+  _measureCallCount++;
+  return YGSize{
+      width = 25.0f,
+      height = 25.0f,
+  };
+}
+
+TEST(YogaTest, setting_compatible_config_maintains_layout_cache) {
+  const YGConfigRef config = YGConfigNew();
+
+  const YGNodeRef root = YGNodeNewWithConfig(config);
+  YGConfigSetPointScaleFactor(config, 1.0f);
+
+  YGNodeStyleSetFlexDirection(root, YGFlexDirectionRow);
+  YGNodeStyleSetWidth(root, 50);
+  YGNodeStyleSetHeight(root, 50);
+
+  const YGNodeRef root_child0 = YGNodeNewWithConfig(config);
+  EXPECT_EQ(0, _measureCallCount);
+
+  YGNodeSetMeasureFunc(root_child0, _measureCustom);
+  YGNodeInsertChild(root, root_child0, 0);
+
+  const YGNodeRef root_child1 = YGNodeNewWithConfig(config);
+  YGNodeStyleSetFlexGrow(root_child1, 1);
+  YGNodeInsertChild(root, root_child1, 1);
+
+  YGNodeCalculateLayout(root, YGUndefined, YGUndefined, YGDirectionLTR);
+  EXPECT_EQ(1, _measureCallCount);
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetLeft(root_child0));
+  ASSERT_FLOAT_EQ(25, YGNodeLayoutGetLeft(root_child1));
+
+  const YGConfigRef config2 = YGConfigNew();
+  // Calling YGConfigSetPointScaleFactor multiple times, ensures that config2
+  // gets a different config version that config1
+  YGConfigSetPointScaleFactor(config2, 1.0f);
+  YGConfigSetPointScaleFactor(config2, 1.5f);
+  YGConfigSetPointScaleFactor(config2, 1.0f);
+
+  YGNodeSetConfig(root, config2);
+  YGNodeSetConfig(root_child0, config2);
+  YGNodeSetConfig(root_child1, config2);
+
+  YGNodeCalculateLayout(root, YGUndefined, YGUndefined, YGDirectionLTR);
+
+  // Measure should not be called again, as layout should have been cached since
+  // config is functionally the same as before
+  EXPECT_EQ(1, _measureCallCount);
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetLeft(root_child0));
+  ASSERT_FLOAT_EQ(25, YGNodeLayoutGetLeft(root_child1));
+
+  YGNodeFreeRecursive(root);
+  YGConfigFree(config);
+  YGConfigFree(config2);
+}

yoga/algorithm/CalculateLayout.cpp

@@ -2140,6 +2140,7 @@ bool calculateLayoutInternal(
 
   const bool needToVisitNode =
       (node->isDirty() && layout->generationCount != generationCount) ||
+      layout->configVersion != node->getConfig()->getVersion() ||
       layout->lastOwnerDirection != ownerDirection;
 
   if (needToVisitNode) {
@@ -2255,6 +2256,7 @@ bool calculateLayoutInternal(
         reason);
 
     layout->lastOwnerDirection = ownerDirection;
+    layout->configVersion = node->getConfig()->getVersion();
 
     if (cachedResults == nullptr) {
       layoutMarkerData.maxMeasureCache = std::max(

yoga/config/Config.cpp

@@ -31,7 +31,10 @@ bool Config::useWebDefaults() const {
 void Config::setExperimentalFeatureEnabled(
     ExperimentalFeature feature,
     bool enabled) {
-  experimentalFeatures_.set(static_cast<size_t>(feature), enabled);
+  if (isExperimentalFeatureEnabled(feature) != enabled) {
+    experimentalFeatures_.set(static_cast<size_t>(feature), enabled);
+    version_++;
+  }
 }
 
 bool Config::isExperimentalFeatureEnabled(ExperimentalFeature feature) const {
@@ -43,15 +46,24 @@ ExperimentalFeatureSet Config::getEnabledExperiments() const {
 }
 
 void Config::setErrata(Errata errata) {
-  errata_ = errata;
+  if (errata_ != errata) {
+    errata_ = errata;
+    version_++;
+  }
 }
 
 void Config::addErrata(Errata errata) {
-  errata_ |= errata;
+  if (!hasErrata(errata)) {
+    errata_ |= errata;
+    version_++;
+  }
 }
 
 void Config::removeErrata(Errata errata) {
-  errata_ &= (~errata);
+  if (hasErrata(errata)) {
+    errata_ &= (~errata);
+    version_++;
+  }
 }
 
 Errata Config::getErrata() const {
@@ -63,7 +75,10 @@ bool Config::hasErrata(Errata errata) const {
 }
 
 void Config::setPointScaleFactor(float pointScaleFactor) {
-  pointScaleFactor_ = pointScaleFactor;
+  if (pointScaleFactor_ != pointScaleFactor) {
+    pointScaleFactor_ = pointScaleFactor;
+    version_++;
+  }
 }
 
 float Config::getPointScaleFactor() const {
@@ -78,6 +93,10 @@ void* Config::getContext() const {
   return context_;
 }
 
+uint32_t Config::getVersion() const noexcept {
+  return version_;
+}
+
 void Config::setLogger(YGLogger logger) {
   logger_ = logger;
 }

yoga/config/Config.h

@@ -53,6 +53,8 @@ class YG_EXPORT Config : public ::YGConfig {
   void setContext(void* context);
   void* getContext() const;
 
+  uint32_t getVersion() const noexcept;
+
   void setLogger(YGLogger logger);
   void log(
       const yoga::Node* node,
@@ -72,6 +74,7 @@ class YG_EXPORT Config : public ::YGConfig {
 
   bool useWebDefaults_ : 1 = false;
 
+  uint32_t version_ = 0;
   ExperimentalFeatureSet experimentalFeatures_{};
   Errata errata_ = Errata::None;
   float pointScaleFactor_ = 1.0f;

yoga/node/LayoutResults.cpp

@@ -21,6 +21,7 @@ bool LayoutResults::operator==(LayoutResults layout) const {
       direction() == layout.direction() &&
       hadOverflow() == layout.hadOverflow() &&
       lastOwnerDirection == layout.lastOwnerDirection &&
+      configVersion == layout.configVersion &&
       nextCachedMeasurementsIndex == layout.nextCachedMeasurementsIndex &&
       cachedLayout == layout.cachedLayout &&
       computedFlexBasis == layout.computedFlexBasis;

yoga/node/LayoutResults.h

@@ -30,6 +30,7 @@ struct LayoutResults {
   // Instead of recomputing the entire layout every single time, we cache some
   // information to break early when nothing changed
   uint32_t generationCount = 0;
+  uint32_t configVersion = 0;
   Direction lastOwnerDirection = Direction::Inherit;
 
   uint32_t nextCachedMeasurementsIndex = 0;

yoga/node/Node.cpp

@@ -136,6 +136,11 @@ void Node::setConfig(yoga::Config* config) {
 
   if (yoga::configUpdateInvalidatesLayout(*config_, *config)) {
     markDirtyAndPropagate();
+    layout_.configVersion = 0;
+  } else {
+    // If the config is functionally the same, then align the configVersion so
+    // that we can reuse the layout cache
+    layout_.configVersion = config->getVersion();
   }
 
   config_ = config;