layout: Consolidate passes in the sequential path that were consolidated

in the parallel path.

src/components/main/css/matching.rs

@@ -5,21 +5,27 @@
 // High-level interface to CSS selector matching.
 
 use css::node_style::StyledNode;
+use layout::extra::LayoutAuxMethods;
 use layout::incremental;
 use layout::util::LayoutDataAccess;
 use layout::wrapper::LayoutNode;
 
 use extra::arc::Arc;
+use script::layout_interface::LayoutChan;
 use servo_util::smallvec::SmallVec;
 use style::{TNode, Stylist, cascade};
 use style::{Before, After};
 
 pub trait MatchMethods {
     fn match_node(&self, stylist: &Stylist);
-    fn match_subtree(&self, stylist: &Stylist);
+
+    /// Performs aux initialization, selector matching, and cascading sequentially.
+    fn match_and_cascade_subtree(&self,
+                                 stylist: &Stylist,
+                                 layout_chan: &LayoutChan,
+                                 parent: Option<LayoutNode>);
 
     unsafe fn cascade_node(&self, parent: Option<LayoutNode>);
-    fn cascade_subtree(&self, parent: Option<LayoutNode>);
 }
 
 impl<'ln> MatchMethods for LayoutNode<'ln> {
@@ -55,11 +61,22 @@ impl<'ln> MatchMethods for LayoutNode<'ln> {
         }
     }
 
-    fn match_subtree(&self, stylist: &Stylist) {
+    fn match_and_cascade_subtree(&self,
-        for node in self.traverse_preorder() {
+                                 stylist: &Stylist,
-            if node.is_element() {
+                                 layout_chan: &LayoutChan,
-                node.match_node(stylist);
+                                 parent: Option<LayoutNode>) {
-            }
+        self.initialize_layout_data((*layout_chan).clone());
+
+        if self.is_element() {
+            self.match_node(stylist);
+        }
+
+        unsafe {
+            self.cascade_node(parent)
+        }
+
+        for kid in self.children() {
+            kid.match_and_cascade_subtree(stylist, layout_chan, Some(*self))
         }
     }
 
@@ -132,14 +149,5 @@ impl<'ln> MatchMethods for LayoutNode<'ln> {
             }
         }
     }
-
-    fn cascade_subtree(&self, parent: Option<LayoutNode>) {
-        unsafe {
-            self.cascade_node(parent);
-        }
-
-        for kid in self.children() {
-            kid.cascade_subtree(Some(*self));
-        }
-    }
 }
+

src/components/main/layout/layout_task.rs

@@ -11,7 +11,6 @@ use css::node_style::StyledNode;
 use layout::construct::{FlowConstructionResult, FlowConstructor, NoConstructionResult};
 use layout::context::LayoutContext;
 use layout::display_list_builder::{DisplayListBuilder, ToGfxColor};
-use layout::extra::LayoutAuxMethods;
 use layout::flow::{Flow, FlowLeafSet, ImmutableFlowUtils, MutableFlowUtils, MutableOwnedFlowUtils};
 use layout::flow::{PreorderFlowTraversal, PostorderFlowTraversal};
 use layout::flow;
@@ -548,37 +547,24 @@ impl LayoutTask {
         let mut layout_root = profile(time::LayoutStyleRecalcCategory,
                                       self.profiler_chan.clone(),
                                       || {
-            // Initialize layout data for each node.
-            //
-            // FIXME(pcwalton): This is inefficient. We don't need an entire traversal to do this
-            // in sequential mode!
-            if self.parallel_traversal.is_none() {
-                profile(time::LayoutAuxInitCategory, self.profiler_chan.clone(), || {
-                    node.initialize_style_for_subtree(self.chan.clone());
-                });
-            }
-
             // Perform CSS selector matching if necessary.
             match data.damage.level {
                 ReflowDocumentDamage => {}
                 _ => {
                     profile(time::LayoutSelectorMatchCategory, self.profiler_chan.clone(), || {
                         match self.parallel_traversal {
-                            None => node.match_subtree(self.stylist),
+                            None => {
+                                node.match_and_cascade_subtree(self.stylist,
+                                                               &layout_ctx.layout_chan,
+                                                               None)
+                            }
                             Some(ref mut traversal) => {
-                                parallel::match_and_cascade_subtree(node, &mut layout_ctx, traversal)
+                                parallel::match_and_cascade_subtree(node,
+                                                                    &mut layout_ctx,
+                                                                    traversal)
                             }
                         }
-                    });
+                    })
-
-                    // If we're doing layout sequentially, do the cascade separately.
-                    //
-                    // TODO(pcwalton): Integrate this into `match_subtree`.
-                    if self.parallel_traversal.is_none() {
-                        profile(time::LayoutSelectorCascadeCategory, self.profiler_chan.clone(), || {
-                            node.cascade_subtree(None);
-                        });
-                    }
                 }
             }
 

src/components/main/servo.rc

@@ -100,7 +100,7 @@ pub mod layout {
     pub mod util;
     pub mod incremental;
     pub mod wrapper;
-    mod extra;
+    pub mod extra;
 }
 
 pub mod windowing;

src/components/util/time.rs

@@ -51,9 +51,7 @@ pub enum ProfilerCategory {
     LayoutQueryCategory,
     LayoutPerformCategory,
     LayoutStyleRecalcCategory,
-    LayoutAuxInitCategory,
     LayoutSelectorMatchCategory,
-    LayoutSelectorCascadeCategory,
     LayoutTreeBuilderCategory,
     LayoutDamagePropagateCategory,
     LayoutMainCategory,
@@ -81,9 +79,7 @@ impl ProfilerCategory {
         buckets.insert(LayoutQueryCategory, ~[]);
         buckets.insert(LayoutPerformCategory, ~[]);
         buckets.insert(LayoutStyleRecalcCategory, ~[]);
-        buckets.insert(LayoutAuxInitCategory, ~[]);
         buckets.insert(LayoutSelectorMatchCategory, ~[]);
-        buckets.insert(LayoutSelectorCascadeCategory, ~[]);
         buckets.insert(LayoutTreeBuilderCategory, ~[]);
         buckets.insert(LayoutMainCategory, ~[]);
         buckets.insert(LayoutParallelWarmupCategory, ~[]);
@@ -107,8 +103,6 @@ impl ProfilerCategory {
             LayoutDispListBuildCategory |
             LayoutShapingCategory |
             LayoutDamagePropagateCategory => "+ ",
-            LayoutAuxInitCategory |
-            LayoutSelectorCascadeCategory |
             LayoutParallelWarmupCategory |
             LayoutSelectorMatchCategory |
             LayoutTreeBuilderCategory => "| + ",