Used hasDirtyChildren tag for the optimization

Summary:
More fine grained dirty marking

Currently a node's dirty flag propagates to the root of the tree ensuring that when any node is invalidated its whole subtree will be re-calculated. This is often times not needed. There are many properties which only effects a node's children and would not need to propagate all the way to the root such as align-items. Also in cases where the style does change layout it may not need to propagate all the way to the root but can often stop at the nearest position: absolute parent.

This change has the potential of greatly improving performance of re-calculating a tree.

This might require adding a second dirty flag named hasDirtyDescendants ensuring that traversal still works even though a parent is not marked as dirty.

Reviewed By: emilsjolander

Differential Revision: D6134754

fbshipit-source-id: bbcfee14058140b946401de756a3f130de0f51cd
This commit is contained in:
Pritesh Nandgaonkar
2017-10-31 08:04:04 -07:00
committed by Facebook Github Bot
parent 132b016bae
commit c5182c4bf5
5 changed files with 101 additions and 7 deletions

View File

@@ -10,6 +10,45 @@
#include <gtest/gtest.h>
#include <yoga/Yoga.h>
TEST(YogaTest, dirty_child_propogation) {
const YGNodeRef root = YGNodeNew();
YGNodeStyleSetAlignItems(root, YGAlignFlexStart);
YGNodeStyleSetHeight(root, 200);
YGNodeStyleSetWidth(root, 500);
const YGNodeRef child0 = YGNodeNew();
YGNodeStyleSetWidth(child0, 30);
YGNodeStyleSetHeight(child0, 30);
YGNodeInsertChild(root, child0, 0);
const YGNodeRef child1 = YGNodeNew();
YGNodeStyleSetPositionType(child1, YGPositionTypeAbsolute);
YGNodeStyleSetPosition(child1, YGEdgeStart, 10);
YGNodeStyleSetPosition(child1, YGEdgeTop, 10);
YGNodeStyleSetWidth(child1, 10);
YGNodeStyleSetHeight(child1, 10);
YGNodeInsertChild(root, child1, 1);
const YGNodeRef child1_child0 = YGNodeNew();
YGNodeStyleSetWidth(child1_child0, 10);
YGNodeStyleSetHeight(child1_child0, 10);
YGNodeInsertChild(child1, child1_child0, 0);
YGNodeCalculateLayout(root, YGUndefined, YGUndefined, YGDirectionLTR);
YGNodeStyleSetWidth(child1_child0, 20);
EXPECT_TRUE(YGNodeIsDirty(child1_child0));
EXPECT_TRUE(YGNodeHasDirtyDescendants(child1));
EXPECT_TRUE(YGNodeIsDirty(child1));
EXPECT_FALSE(YGNodeIsDirty(root));
EXPECT_TRUE(YGNodeHasDirtyDescendants(root));
EXPECT_FALSE(YGNodeIsDirty(child0));
EXPECT_FALSE(YGNodeHasDirtyDescendants(child0));
}
TEST(YogaTest, dirty_propagation) {
const YGNodeRef root = YGNodeNew();
YGNodeStyleSetAlignItems(root, YGAlignFlexStart);