layout: Report memory usage for fragment and box trees. (#36553)

Add memory reporter integration for the fragment and box trees that are
persisted in the layout thread.

Testing: Looked at the numbers for https://servo.org and
https://html.spec.whatwg.org/. The former was very small, but the latter
was 700mb.

---------

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

components/layout_2020/flow/float.rs

@@ -13,6 +13,7 @@ use std::ops::Range;
 
 use app_units::{Au, MAX_AU, MIN_AU};
 use euclid::num::Zero;
+use malloc_size_of_derive::MallocSizeOf;
 use servo_arc::Arc;
 use style::computed_values::float::T as FloatProperty;
 use style::computed_values::position::T as Position;
@@ -31,7 +32,7 @@ use crate::style_ext::{DisplayInside, PaddingBorderMargin};
 use crate::{ContainingBlock, PropagatedBoxTreeData};
 
 /// A floating box.
-#[derive(Debug)]
+#[derive(Debug, MallocSizeOf)]
 pub(crate) struct FloatBox {
     /// The formatting context that makes up the content of this box.
     pub contents: IndependentFormattingContext,

components/layout_2020/flow/inline/inline_box.rs

@@ -6,6 +6,7 @@ use std::vec::IntoIter;
 
 use app_units::Au;
 use fonts::FontMetrics;
+use malloc_size_of_derive::MallocSizeOf;
 
 use super::{InlineContainerState, InlineContainerStateFlags, inline_container_needs_strut};
 use crate::ContainingBlock;
@@ -17,7 +18,7 @@ use crate::fragment_tree::BaseFragmentInfo;
 use crate::layout_box_base::LayoutBoxBase;
 use crate::style_ext::{LayoutStyle, PaddingBorderMargin};
 
-#[derive(Debug)]
+#[derive(Debug, MallocSizeOf)]
 pub(crate) struct InlineBox {
     pub base: LayoutBoxBase,
     /// The identifier of this inline box in the containing [`super::InlineFormattingContext`].
@@ -56,7 +57,7 @@ impl InlineBox {
     }
 }
 
-#[derive(Debug, Default)]
+#[derive(Debug, Default, MallocSizeOf)]
 pub(crate) struct InlineBoxes {
     /// A collection of all inline boxes in a particular [`super::InlineFormattingContext`].
     inline_boxes: Vec<ArcRefCell<InlineBox>>,
@@ -162,7 +163,7 @@ impl InlineBoxes {
     }
 }
 
-#[derive(Clone, Copy, Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq)]
 pub(super) enum InlineBoxTreePathToken {
     Start(InlineBoxIdentifier),
     End(InlineBoxIdentifier),
@@ -183,7 +184,7 @@ impl InlineBoxTreePathToken {
 /// [`u32`] is used for the index, in order to save space. The value refers to the token
 /// in the start tree data structure which can be fetched to find the actual index of
 /// of the [`InlineBox`] in [`InlineBoxes::inline_boxes`].
-#[derive(Clone, Copy, Debug, Default, Eq, Hash, PartialEq)]
+#[derive(Clone, Copy, Debug, Default, Eq, Hash, MallocSizeOf, PartialEq)]
 pub(crate) struct InlineBoxIdentifier {
     pub index_of_start_in_tree: u32,
     pub index_in_inline_boxes: u32,

components/layout_2020/flow/inline/mod.rs

@@ -88,6 +88,7 @@ use line::{
     TextRunLineItem,
 };
 use line_breaker::LineBreaker;
+use malloc_size_of_derive::MallocSizeOf;
 use range::Range;
 use servo_arc::Arc;
 use style::Zero;
@@ -136,7 +137,7 @@ use crate::{ConstraintSpace, ContainingBlock, PropagatedBoxTreeData};
 static FONT_SUBSCRIPT_OFFSET_RATIO: f32 = 0.20;
 static FONT_SUPERSCRIPT_OFFSET_RATIO: f32 = 0.34;
 
-#[derive(Debug)]
+#[derive(Debug, MallocSizeOf)]
 pub(crate) struct InlineFormattingContext {
     /// All [`InlineItem`]s in this [`InlineFormattingContext`] stored in a flat array.
     /// [`InlineItem::StartInlineBox`] and [`InlineItem::EndInlineBox`] allow representing
@@ -173,14 +174,14 @@ pub(crate) struct InlineFormattingContext {
 }
 
 /// A collection of data used to cache [`FontMetrics`] in the [`InlineFormattingContext`]
-#[derive(Debug)]
+#[derive(Debug, MallocSizeOf)]
 pub(crate) struct FontKeyAndMetrics {
     pub key: FontInstanceKey,
     pub pt_size: Au,
     pub metrics: FontMetrics,
 }
 
-#[derive(Debug)]
+#[derive(Debug, MallocSizeOf)]
 pub(crate) enum InlineItem {
     StartInlineBox(ArcRefCell<InlineBox>),
     EndInlineBox,
@@ -189,9 +190,9 @@ pub(crate) enum InlineItem {
         ArcRefCell<AbsolutelyPositionedBox>,
         usize, /* offset_in_text */
     ),
-    OutOfFlowFloatBox(Arc<FloatBox>),
+    OutOfFlowFloatBox(#[conditional_malloc_size_of] Arc<FloatBox>),
     Atomic(
-        Arc<IndependentFormattingContext>,
+        #[conditional_malloc_size_of] Arc<IndependentFormattingContext>,
         usize, /* offset_in_text */
         Level, /* bidi_level */
     ),

components/layout_2020/flow/inline/text_run.rs

@@ -12,6 +12,7 @@ use fonts::{
 };
 use fonts_traits::ByteIndex;
 use log::warn;
+use malloc_size_of_derive::MallocSizeOf;
 use range::Range as ServoRange;
 use servo_arc::Arc;
 use style::computed_values::text_rendering::T as TextRendering;
@@ -37,9 +38,10 @@ pub(crate) const XI_LINE_BREAKING_CLASS_WJ: u8 = 30;
 pub(crate) const XI_LINE_BREAKING_CLASS_ZWJ: u8 = 42;
 
 /// <https://www.w3.org/TR/css-display-3/#css-text-run>
-#[derive(Debug)]
+#[derive(Debug, MallocSizeOf)]
 pub(crate) struct TextRun {
     pub base_fragment_info: BaseFragmentInfo,
+    #[conditional_malloc_size_of]
     pub parent_style: Arc<ComputedValues>,
     pub text_range: Range<usize>,
 
@@ -47,6 +49,7 @@ pub(crate) struct TextRun {
     /// segments, and shaped.
     pub shaped_text: Vec<TextRunSegment>,
     pub selection_range: Option<ServoRange<ByteIndex>>,
+    #[conditional_malloc_size_of]
     pub selected_style: Arc<ComputedValues>,
 }
 
@@ -64,7 +67,7 @@ enum SegmentStartSoftWrapPolicy {
     FollowLinebreaker,
 }
 
-#[derive(Debug)]
+#[derive(Debug, MallocSizeOf)]
 pub(crate) struct TextRunSegment {
     /// The index of this font in the parent [`super::InlineFormattingContext`]'s collection of font
     /// information.

components/layout_2020/flow/mod.rs

@@ -7,6 +7,7 @@
 
 use app_units::{Au, MAX_AU};
 use inline::InlineFormattingContext;
+use malloc_size_of_derive::MallocSizeOf;
 use rayon::iter::{IndexedParallelIterator, IntoParallelRefIterator, ParallelIterator};
 use servo_arc::Arc;
 use style::Zero;
@@ -53,13 +54,13 @@ mod root;
 pub(crate) use construct::BlockContainerBuilder;
 pub use root::{BoxTree, CanvasBackground};
 
-#[derive(Debug)]
+#[derive(Debug, MallocSizeOf)]
 pub(crate) struct BlockFormattingContext {
     pub contents: BlockContainer,
     pub contains_floats: bool,
 }
 
-#[derive(Debug)]
+#[derive(Debug, MallocSizeOf)]
 pub(crate) enum BlockContainer {
     BlockLevelBoxes(Vec<ArcRefCell<BlockLevelBox>>),
     InlineFormattingContext(InlineFormattingContext),
@@ -76,7 +77,7 @@ impl BlockContainer {
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, MallocSizeOf)]
 pub(crate) enum BlockLevelBox {
     Independent(IndependentFormattingContext),
     OutOfFlowAbsolutelyPositionedBox(ArcRefCell<AbsolutelyPositionedBox>),
@@ -246,8 +247,9 @@ pub(crate) struct CollapsibleWithParentStartMargin(bool);
 
 /// The contentes of a BlockContainer created to render a list marker
 /// for a list that has `list-style-position: outside`.
-#[derive(Debug)]
+#[derive(Debug, MallocSizeOf)]
 pub(crate) struct OutsideMarker {
+    #[conditional_malloc_size_of]
     pub list_item_style: Arc<ComputedValues>,
     pub base: LayoutBoxBase,
     pub block_container: BlockContainer,

components/layout_2020/flow/root.rs

@@ -5,6 +5,7 @@
 use app_units::Au;
 use atomic_refcell::AtomicRef;
 use compositing_traits::display_list::AxesScrollSensitivity;
+use malloc_size_of_derive::MallocSizeOf;
 use script_layout_interface::wrapper_traits::{
     LayoutNode, ThreadSafeLayoutElement, ThreadSafeLayoutNode,
 };
@@ -32,6 +33,7 @@ use crate::style_ext::{ComputedValuesExt, Display, DisplayGeneratingBox, Display
 use crate::taffy::{TaffyItemBox, TaffyItemBoxInner};
 use crate::{DefiniteContainingBlock, PropagatedBoxTreeData};
 
+#[derive(MallocSizeOf)]
 pub struct BoxTree {
     /// Contains typically exactly one block-level box, which was generated by the root element.
     /// There may be zero if that element has `display: none`.
@@ -437,7 +439,7 @@ impl BoxTree {
 }
 
 /// <https://drafts.csswg.org/css-backgrounds/#root-background>
-#[derive(Clone)]
+#[derive(Clone, MallocSizeOf)]
 pub struct CanvasBackground {
     /// DOM node for the root element
     pub root_element: OpaqueNode,
@@ -448,6 +450,7 @@ pub struct CanvasBackground {
     pub from_element: OpaqueNode,
 
     /// The computed styles to take background properties from.
+    #[conditional_malloc_size_of]
     pub style: Option<Arc<ComputedValues>>,
 }