Revert "LibWeb: Cache intrinsic sizes across layout runs"

This reverts commit 12c6ac78e2.

Very large performance regression when viewing GitHub repository pages.

Libraries/LibWeb/Animations/KeyframeEffect.cpp

@@ -962,7 +962,7 @@ void KeyframeEffect::update_computed_properties()
     }
 
     if (invalidation.relayout)
-        target->set_needs_layout_update(DOM::SetNeedsLayoutReason::KeyframeEffect);
+        document.set_needs_layout(DOM::SetNeedsLayoutReason::KeyframeEffect);
     if (invalidation.rebuild_layout_tree)
         document.invalidate_layout_tree(DOM::InvalidateLayoutTreeReason::KeyframeEffect);
     if (invalidation.repaint) {

Libraries/LibWeb/DOM/CharacterData.cpp

@@ -147,7 +147,7 @@ WebIDL::ExceptionOr<void> CharacterData::replace_data(size_t offset, size_t coun
         static_cast<Layout::TextNode&>(*layout_node).invalidate_text_for_rendering();
 
         // We also need to relayout.
-        set_needs_layout_update(SetNeedsLayoutReason::CharacterDataReplaceData);
+        document().set_needs_layout(SetNeedsLayoutReason::CharacterDataReplaceData);
     }
 
     document().bump_character_data_version();

Libraries/LibWeb/DOM/Document.cpp

@@ -1211,6 +1211,20 @@ Optional<String> Document::encoding_parse_and_serialize_url(StringView url) cons
     return parsed_url->serialize();
 }
 
+void Document::set_needs_layout(SetNeedsLayoutReason reason)
+{
+    if (m_needs_layout)
+        return;
+    if constexpr (UPDATE_LAYOUT_DEBUG) {
+        // NOTE: We check some conditions here to avoid debug spam in documents that don't do layout.
+        auto navigable = this->navigable();
+        if (m_layout_root && navigable && navigable->active_document() == this)
+            dbgln_if(UPDATE_LAYOUT_DEBUG, "NEED LAYOUT {}", to_string(reason));
+    }
+    m_needs_layout = true;
+    schedule_layout_update();
+}
+
 void Document::invalidate_layout_tree(InvalidateLayoutTreeReason reason)
 {
     if (m_layout_root)
@@ -1285,7 +1299,7 @@ void Document::update_layout(UpdateLayoutReason reason)
 
     update_style();
 
-    if (!m_needs_layout_update && m_layout_root)
+    if (!m_needs_layout && m_layout_root)
         return;
 
     // NOTE: If this is a document hosting <template> contents, layout is unnecessary.
@@ -1315,16 +1329,11 @@ void Document::update_layout(UpdateLayoutReason reason)
         }
     }
 
+    // Assign each box that establishes a formatting context a list of absolutely positioned children it should take care of during layout
     m_layout_root->for_each_in_inclusive_subtree_of_type<Layout::Box>([&](auto& child) {
-        bool needs_layout_update = child.dom_node() && child.dom_node()->needs_layout_update();
-        if (needs_layout_update || child.is_anonymous()) {
-            child.reset_cached_intrinsic_sizes();
-        }
         child.clear_contained_abspos_children();
         return TraversalDecision::Continue;
     });
-
-    // Assign each box that establishes a formatting context a list of absolutely positioned children it should take care of during layout
     m_layout_root->for_each_in_inclusive_subtree([&](auto& child) {
         if (!child.is_absolutely_positioned())
             return TraversalDecision::Continue;
@@ -1387,10 +1396,7 @@ void Document::update_layout(UpdateLayoutReason reason)
         paintable()->recompute_selection_states(*range);
     }
 
-    for_each_shadow_including_inclusive_descendant([](auto& node) {
+    m_needs_layout = false;
-        node.reset_needs_layout_update();
-        return TraversalDecision::Continue;
-    });
 
     // Scrolling by zero offset will clamp scroll offset back to valid range if it was out of bounds
     // after the viewport size change.
@@ -1424,9 +1430,6 @@ void Document::update_layout(UpdateLayoutReason reason)
         }
         is_display_none = static_cast<Element&>(node).computed_properties()->display().is_none();
     }
-    if (node_invalidation.relayout) {
-        node.set_needs_layout_update(SetNeedsLayoutReason::StyleChange);
-    }
     if (node_invalidation.rebuild_layout_tree) {
         // We mark layout tree for rebuild starting from parent element to correctly invalidate
         // "display" property change to/from "contents" value.
@@ -1438,7 +1441,6 @@ void Document::update_layout(UpdateLayoutReason reason)
     }
     invalidation |= node_invalidation;
     node.set_needs_style_update(false);
-    invalidation |= node_invalidation;
 
     bool children_need_inherited_style_update = !invalidation.is_none();
     if (needs_full_style_update || node.child_needs_style_update() || children_need_inherited_style_update) {
@@ -1530,6 +1532,8 @@ void Document::update_style()
     auto invalidation = update_style_recursively(*this, style_computer(), false);
     if (!invalidation.is_none())
         invalidate_display_list();
+    if (invalidation.relayout)
+        set_needs_layout(SetNeedsLayoutReason::StyleChange);
     if (invalidation.rebuild_stacking_context_tree)
         invalidate_stacking_context_tree();
     m_needs_full_style_update = false;

Libraries/LibWeb/DOM/Document.h

@@ -50,6 +50,26 @@ enum class QuirksMode {
     Yes
 };
 
+#define ENUMERATE_SET_NEEDS_LAYOUT_REASONS(X)         \
+    X(CharacterDataReplaceData)                       \
+    X(FinalizeACrossDocumentNavigation)               \
+    X(HTMLImageElementReactToChangesInTheEnvironment) \
+    X(HTMLImageElementUpdateTheImageData)             \
+    X(HTMLVideoElementSetVideoTrack)                  \
+    X(KeyframeEffect)                                 \
+    X(LayoutTreeUpdate)                               \
+    X(NavigableSetViewportSize)                       \
+    X(SVGImageElementFetchTheDocument)                \
+    X(StyleChange)
+
+enum class SetNeedsLayoutReason {
+#define ENUMERATE_SET_NEEDS_LAYOUT_REASON(e) e,
+    ENUMERATE_SET_NEEDS_LAYOUT_REASONS(ENUMERATE_SET_NEEDS_LAYOUT_REASON)
+#undef ENUMERATE_SET_NEEDS_LAYOUT_REASON
+};
+
+[[nodiscard]] StringView to_string(SetNeedsLayoutReason);
+
 #define ENUMERATE_INVALIDATE_LAYOUT_TREE_REASONS(X)       \
     X(DocumentAddAnElementToTheTopLayer)                  \
     X(DocumentRequestAnElementToBeRemovedFromTheTopLayer) \
@@ -338,6 +358,8 @@ public:
     void update_paint_and_hit_testing_properties_if_needed();
     void update_animated_style_if_needed();
 
+    void set_needs_layout(SetNeedsLayoutReason);
+
     void invalidate_layout_tree(InvalidateLayoutTreeReason);
     void invalidate_stacking_context_tree();
 
@@ -1054,6 +1076,8 @@ private:
     // Used by evaluate_media_queries_and_report_changes().
     Vector<WeakPtr<CSS::MediaQueryList>> m_media_query_lists;
 
+    bool m_needs_layout { false };
+
     bool m_needs_full_style_update { false };
     bool m_needs_full_layout_tree_update { false };
 

Libraries/LibWeb/DOM/Node.cpp

@@ -1405,7 +1405,7 @@ void Node::set_needs_layout_tree_update(bool value)
                 break;
             ancestor->m_child_needs_layout_tree_update = true;
         }
-        set_needs_layout_update(SetNeedsLayoutReason::LayoutTreeUpdate);
+        document().set_needs_layout(SetNeedsLayoutReason::LayoutTreeUpdate);
     }
 }
 
@@ -1425,27 +1425,6 @@ void Node::set_needs_style_update(bool value)
     }
 }
 
-void Node::set_needs_layout_update(SetNeedsLayoutReason reason)
-{
-    if (m_needs_layout_update)
-        return;
-
-    if constexpr (UPDATE_LAYOUT_DEBUG) {
-        // NOTE: We check some conditions here to avoid debug spam in documents that don't do layout.
-        auto navigable = this->navigable();
-        if (navigable && navigable->active_document() == this)
-            dbgln_if(UPDATE_LAYOUT_DEBUG, "NEED LAYOUT {}", to_string(reason));
-    }
-
-    m_needs_layout_update = true;
-
-    for (auto* ancestor = parent_or_shadow_host(); ancestor; ancestor = ancestor->parent_or_shadow_host()) {
-        if (ancestor->m_needs_layout_update)
-            break;
-        ancestor->m_needs_layout_update = true;
-    }
-}
-
 void Node::post_connection()
 {
 }

Libraries/LibWeb/DOM/Node.h

@@ -91,26 +91,6 @@ enum class StyleInvalidationReason {
 #undef __ENUMERATE_STYLE_INVALIDATION_REASON
 };
 
-#define ENUMERATE_SET_NEEDS_LAYOUT_REASONS(X)         \
-    X(CharacterDataReplaceData)                       \
-    X(FinalizeACrossDocumentNavigation)               \
-    X(HTMLImageElementReactToChangesInTheEnvironment) \
-    X(HTMLImageElementUpdateTheImageData)             \
-    X(HTMLVideoElementSetVideoTrack)                  \
-    X(KeyframeEffect)                                 \
-    X(LayoutTreeUpdate)                               \
-    X(NavigableSetViewportSize)                       \
-    X(SVGImageElementFetchTheDocument)                \
-    X(StyleChange)
-
-enum class SetNeedsLayoutReason {
-#define ENUMERATE_SET_NEEDS_LAYOUT_REASON(e) e,
-    ENUMERATE_SET_NEEDS_LAYOUT_REASONS(ENUMERATE_SET_NEEDS_LAYOUT_REASON)
-#undef ENUMERATE_SET_NEEDS_LAYOUT_REASON
-};
-
-[[nodiscard]] StringView to_string(SetNeedsLayoutReason);
-
 class Node : public EventTarget
     , public TreeNode<Node> {
     WEB_PLATFORM_OBJECT(Node, EventTarget);
@@ -311,10 +291,6 @@ public:
     void set_needs_style_update(bool);
     void set_needs_style_update_internal(bool) { m_needs_style_update = true; }
 
-    bool needs_layout_update() const { return m_needs_layout_update; }
-    void set_needs_layout_update(SetNeedsLayoutReason);
-    void reset_needs_layout_update() { m_needs_layout_update = false; }
-
     bool child_needs_style_update() const { return m_child_needs_style_update; }
     void set_child_needs_style_update(bool b) { m_child_needs_style_update = b; }
 
@@ -552,8 +528,6 @@ protected:
     bool m_child_needs_style_update { false };
     bool m_entire_subtree_needs_style_update { false };
 
-    bool m_needs_layout_update { false };
-
     UniqueNodeID m_unique_id;
 
     // https://dom.spec.whatwg.org/#registered-observer-list

Libraries/LibWeb/HTML/HTMLImageElement.cpp

@@ -762,7 +762,7 @@ void HTMLImageElement::add_callbacks_to_image_request(GC::Ref<ImageRequest> imag
                 document().list_of_available_images().add(key, *image_data, true);
 
                 set_needs_style_update(true);
-                set_needs_layout_update(DOM::SetNeedsLayoutReason::HTMLImageElementUpdateTheImageData);
+                document().set_needs_layout(DOM::SetNeedsLayoutReason::HTMLImageElementUpdateTheImageData);
 
                 // 4. If maybe omit events is not set or previousURL is not equal to urlString, then fire an event named load at the img element.
                 if (!maybe_omit_events || previous_url != url_string.serialize())
@@ -902,7 +902,7 @@ void HTMLImageElement::react_to_changes_in_the_environment()
             image_request->prepare_for_presentation(*this);
             // FIXME: This is ad-hoc, updating the layout here should probably be handled by prepare_for_presentation().
             set_needs_style_update(true);
-            set_needs_layout_update(DOM::SetNeedsLayoutReason::HTMLImageElementReactToChangesInTheEnvironment);
+            document().set_needs_layout(DOM::SetNeedsLayoutReason::HTMLImageElementReactToChangesInTheEnvironment);
 
             // 7. Fire an event named load at the img element.
             dispatch_event(DOM::Event::create(realm(), HTML::EventNames::load));

Libraries/LibWeb/HTML/HTMLVideoElement.cpp

@@ -111,7 +111,7 @@ u32 HTMLVideoElement::video_height() const
 void HTMLVideoElement::set_video_track(GC::Ptr<HTML::VideoTrack> video_track)
 {
     set_needs_style_update(true);
-    set_needs_layout_update(DOM::SetNeedsLayoutReason::HTMLVideoElementSetVideoTrack);
+    document().set_needs_layout(DOM::SetNeedsLayoutReason::HTMLVideoElementSetVideoTrack);
 
     if (m_video_track)
         m_video_track->pause_video({});

Libraries/LibWeb/HTML/Navigable.cpp

@@ -2100,7 +2100,7 @@ void finalize_a_cross_document_navigation(GC::Ref<Navigable> navigable, HistoryH
     // AD-HOC: If we're inside a navigable container, let's trigger a relayout in the container document.
     //         This allows size negotiation between the containing document and SVG documents to happen.
     if (auto container = navigable->container()) {
-        container->set_needs_layout_update(DOM::SetNeedsLayoutReason::FinalizeACrossDocumentNavigation);
+        container->document().set_needs_layout(DOM::SetNeedsLayoutReason::FinalizeACrossDocumentNavigation);
     }
 }
 
@@ -2223,7 +2223,7 @@ void Navigable::set_viewport_size(CSSPixelSize size)
     if (auto document = active_document()) {
         // NOTE: Resizing the viewport changes the reference value for viewport-relative CSS lengths.
         document->invalidate_style(DOM::StyleInvalidationReason::NavigableSetViewportSize);
-        document->set_needs_layout_update(DOM::SetNeedsLayoutReason::NavigableSetViewportSize);
+        document->set_needs_layout(DOM::SetNeedsLayoutReason::NavigableSetViewportSize);
     }
 
     if (auto document = active_document()) {

Libraries/LibWeb/Layout/Box.h

@@ -17,13 +17,6 @@ struct LineBoxFragmentCoordinate {
     size_t fragment_index { 0 };
 };
 
-struct IntrinsicSizes {
-    Optional<CSSPixels> min_content_width;
-    Optional<CSSPixels> max_content_width;
-    HashMap<CSSPixels, Optional<CSSPixels>> min_content_height;
-    HashMap<CSSPixels, Optional<CSSPixels>> max_content_height;
-};
-
 class Box : public NodeWithStyleAndBoxModelMetrics {
     GC_CELL(Box, NodeWithStyleAndBoxModelMetrics);
 
@@ -60,14 +53,6 @@ public:
 
     virtual void visit_edges(Cell::Visitor&) override;
 
-    IntrinsicSizes& cached_intrinsic_sizes() const
-    {
-        if (!m_cached_intrinsic_sizes)
-            m_cached_intrinsic_sizes = make<IntrinsicSizes>();
-        return *m_cached_intrinsic_sizes;
-    }
-    void reset_cached_intrinsic_sizes() const { m_cached_intrinsic_sizes.clear(); }
-
 protected:
     Box(DOM::Document&, DOM::Node*, GC::Ref<CSS::ComputedProperties>);
     Box(DOM::Document&, DOM::Node*, NonnullOwnPtr<CSS::ComputedValues>);
@@ -80,8 +65,6 @@ private:
     Optional<CSSPixelFraction> m_natural_aspect_ratio;
 
     Vector<GC::Ref<Node>> m_contained_abspos_children;
-
-    OwnPtr<IntrinsicSizes> mutable m_cached_intrinsic_sizes;
 };
 
 template<>

Libraries/LibWeb/Layout/FormattingContext.cpp

@@ -1442,9 +1442,11 @@ CSSPixels FormattingContext::calculate_min_content_width(Layout::Box const& box)
     if (box.has_natural_width())
         return *box.natural_width();
 
-    auto& cache = box.cached_intrinsic_sizes().min_content_width;
+    auto& root_state = m_state.m_root;
-    if (cache.has_value())
+
-        return cache.value();
+    auto& cache = *root_state.intrinsic_sizes.ensure(&box, [] { return adopt_own(*new LayoutState::IntrinsicSizes); });
+    if (cache.min_content_width.has_value())
+        return *cache.min_content_width;
 
     LayoutState throwaway_state(&m_state);
 
@@ -1464,9 +1466,8 @@ CSSPixels FormattingContext::calculate_min_content_width(Layout::Box const& box)
 
     context->run(AvailableSpace(available_width, available_height));
 
-    auto min_content_width = clamp_to_max_dimension_value(context->automatic_content_width());
+    cache.min_content_width = clamp_to_max_dimension_value(context->automatic_content_width());
-    cache.emplace(min_content_width);
+    return *cache.min_content_width;
-    return min_content_width;
 }
 
 CSSPixels FormattingContext::calculate_max_content_width(Layout::Box const& box) const
@@ -1474,9 +1475,11 @@ CSSPixels FormattingContext::calculate_max_content_width(Layout::Box const& box)
     if (box.has_natural_width())
         return *box.natural_width();
 
-    auto& cache = box.cached_intrinsic_sizes().max_content_width;
+    auto& root_state = m_state.m_root;
-    if (cache.has_value())
+
-        return cache.value();
+    auto& cache = *root_state.intrinsic_sizes.ensure(&box, [] { return adopt_own(*new LayoutState::IntrinsicSizes); });
+    if (cache.max_content_width.has_value())
+        return *cache.max_content_width;
 
     LayoutState throwaway_state(&m_state);
 
@@ -1496,9 +1499,8 @@ CSSPixels FormattingContext::calculate_max_content_width(Layout::Box const& box)
 
     context->run(AvailableSpace(available_width, available_height));
 
-    auto max_content_width = clamp_to_max_dimension_value(context->automatic_content_width());
+    cache.max_content_width = clamp_to_max_dimension_value(context->automatic_content_width());
-    cache.emplace(max_content_width);
+    return *cache.max_content_width;
-    return max_content_width;
 }
 
 // https://www.w3.org/TR/css-sizing-3/#min-content-block-size
@@ -1511,9 +1513,14 @@ CSSPixels FormattingContext::calculate_min_content_height(Layout::Box const& box
     if (box.has_natural_height())
         return *box.natural_height();
 
-    auto cache_slot = box.cached_intrinsic_sizes().min_content_height.ensure(width);
+    auto get_cache_slot = [&]() -> Optional<CSSPixels>* {
-    if (cache_slot.has_value())
+        auto& root_state = m_state.m_root;
-        return cache_slot.value();
+        auto& cache = *root_state.intrinsic_sizes.ensure(&box, [] { return adopt_own(*new LayoutState::IntrinsicSizes); });
+        return &cache.min_content_height.ensure(width);
+    };
+
+    if (auto* cache_slot = get_cache_slot(); cache_slot && cache_slot->has_value())
+        return cache_slot->value();
 
     LayoutState throwaway_state(&m_state);
 
@@ -1530,7 +1537,9 @@ CSSPixels FormattingContext::calculate_min_content_height(Layout::Box const& box
     context->run(AvailableSpace(AvailableSize::make_definite(width), AvailableSize::make_min_content()));
 
     auto min_content_height = clamp_to_max_dimension_value(context->automatic_content_height());
-    cache_slot.emplace(min_content_height);
+    if (auto* cache_slot = get_cache_slot()) {
+        *cache_slot = min_content_height;
+    }
     return min_content_height;
 }
 
@@ -1542,9 +1551,14 @@ CSSPixels FormattingContext::calculate_max_content_height(Layout::Box const& box
     if (box.has_natural_height())
         return *box.natural_height();
 
-    auto& cache_slot = box.cached_intrinsic_sizes().max_content_height.ensure(width);
+    auto get_cache_slot = [&]() -> Optional<CSSPixels>* {
-    if (cache_slot.has_value())
+        auto& root_state = m_state.m_root;
-        return cache_slot.value();
+        auto& cache = *root_state.intrinsic_sizes.ensure(&box, [] { return adopt_own(*new LayoutState::IntrinsicSizes); });
+        return &cache.max_content_height.ensure(width);
+    };
+
+    if (auto* cache_slot = get_cache_slot(); cache_slot && cache_slot->has_value())
+        return cache_slot->value();
 
     LayoutState throwaway_state(&m_state);
 
@@ -1561,7 +1575,11 @@ CSSPixels FormattingContext::calculate_max_content_height(Layout::Box const& box
     context->run(AvailableSpace(AvailableSize::make_definite(width), AvailableSize::make_max_content()));
 
     auto max_content_height = clamp_to_max_dimension_value(context->automatic_content_height());
-    cache_slot.emplace(max_content_height);
+
+    if (auto* cache_slot = get_cache_slot()) {
+        *cache_slot = max_content_height;
+    }
+
     return max_content_height;
 }
 

Libraries/LibWeb/Layout/LayoutState.h

@@ -221,6 +221,18 @@ struct LayoutState {
 
     HashMap<GC::Ref<Layout::Node const>, NonnullOwnPtr<UsedValues>> used_values_per_layout_node;
 
+    // We cache intrinsic sizes once determined, as they will not change over the course of a full layout.
+    // This avoids computing them several times while performing flex layout.
+    struct IntrinsicSizes {
+        Optional<CSSPixels> min_content_width;
+        Optional<CSSPixels> max_content_width;
+
+        HashMap<CSSPixels, Optional<CSSPixels>> min_content_height;
+        HashMap<CSSPixels, Optional<CSSPixels>> max_content_height;
+    };
+
+    HashMap<GC::Ptr<NodeWithStyle const>, NonnullOwnPtr<IntrinsicSizes>> mutable intrinsic_sizes;
+
     LayoutState const* m_parent { nullptr };
     LayoutState const& m_root;
 

Libraries/LibWeb/SVG/SVGImageElement.cpp

@@ -168,7 +168,7 @@ void SVGImageElement::fetch_the_document(URL::URL const& url)
                 m_animation_timer->start();
             }
             set_needs_style_update(true);
-            set_needs_layout_update(DOM::SetNeedsLayoutReason::SVGImageElementFetchTheDocument);
+            document().set_needs_layout(DOM::SetNeedsLayoutReason::SVGImageElementFetchTheDocument);
 
             dispatch_event(DOM::Event::create(realm(), HTML::EventNames::load));
         },