Changeset 143498 in webkit

Timestamp:

Feb 20, 2013 1:43:29 PM (11 years ago)

Author:

fmalita@chromium.org

Message:

[SVG] Update of element referenced by multiple 'use' nodes is absurdly slow
​https://bugs.webkit.org/show_bug.cgi?id=97905

Reviewed by Dirk Schulze.

Rebuilding the shadow and instance trees of dependent use nodes recursively can be
extremely inefficient with non-trivial dependency graphs (the trees are not constructed
in topological order).

To avoid redundant buildShadowAndInstanceTree() invokations, separate the invalidation
phase from the actual tree (re)building phase, and only descend into the dependency DAG
during the invalidation phase (recursion also stops at nodes that have been previously
invalidated).

No new tests: functional coverage provided by existing tests, perfomance tracked by
PerformanceTests/SVG/SvgNestedUse.html.

• svg/SVGUseElement.cpp:

(WebCore::SVGUseElement::buildPendingResource):
(WebCore::SVGUseElement::buildShadowAndInstanceTree):
(WebCore::SVGUseElement::invalidateShadowTree):
(WebCore):
(WebCore::SVGUseElement::invalidateDependentShadowTrees):

• svg/SVGUseElement.h:

(SVGUseElement):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• svg/SVGUseElement.cpp (modified) (4 diffs)
• svg/SVGUseElement.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2013-02-20  Florin Malita  <fmalita@chromium.org>
+
+        [SVG] Update of element referenced by multiple 'use' nodes is absurdly slow
+        https://bugs.webkit.org/show_bug.cgi?id=97905
+
+        Reviewed by Dirk Schulze.
+
+        Rebuilding the shadow and instance trees of dependent use nodes recursively can be
+        extremely inefficient with non-trivial dependency graphs (the trees are not constructed
+        in topological order).
+
+        To avoid redundant buildShadowAndInstanceTree() invokations, separate the invalidation
+        phase from the actual tree (re)building phase, and only descend into the dependency DAG
+        during the invalidation phase (recursion also stops at nodes that have been previously
+        invalidated).
+
+        No new tests: functional coverage provided by existing tests, perfomance tracked by
+        PerformanceTests/SVG/SvgNestedUse.html.
+
+        * svg/SVGUseElement.cpp:
+        (WebCore::SVGUseElement::buildPendingResource):
+        (WebCore::SVGUseElement::buildShadowAndInstanceTree):
+        (WebCore::SVGUseElement::invalidateShadowTree):
+        (WebCore):
+        (WebCore::SVGUseElement::invalidateDependentShadowTrees):
+        * svg/SVGUseElement.h:
+        (SVGUseElement):
+
 2013-02-20  Tim Horton  <timothy_horton@apple.com>
 

trunk/Source/WebCore/svg/SVGUseElement.cpp

@@ -410 +410 @@
 void SVGUseElement::buildPendingResource()
 {
-    if (!referencedDocument())
+    if (!referencedDocument() || isInShadowTree())
         return;
     clearResourceReferences();
-    if (!inDocument() || isInShadowTree())
+    if (!inDocument())
         return;
 
@@ -431 +431 @@
     }
 
-    if (target->isSVGElement())
+    if (target->isSVGElement()) {
         buildShadowAndInstanceTree(static_cast<SVGElement*>(target));
+        invalidateDependentShadowTrees();
+    }
+
     ASSERT(!m_needsShadowTreeRecreation);
 }
@@ -517 +520 @@
     // Update relative length information.
     updateRelativeLengthsInformation();
-
-    // Rebuild all dependent use elements.
-    ASSERT(document());
-    document()->accessSVGExtensions()->rebuildAllElementReferencesForTarget(this);
 
     // Eventually dump instance tree
@@ -907 +906 @@
     m_needsShadowTreeRecreation = true;
     setNeedsStyleRecalc();
+    invalidateDependentShadowTrees();
+}
+
+void SVGUseElement::invalidateDependentShadowTrees()
+{
+    // Recursively invalidate dependent <use> shadow trees
+    const HashSet<SVGElementInstance*>& instances = instancesForElement();
+    const HashSet<SVGElementInstance*>::const_iterator end = instances.end();
+    for (HashSet<SVGElementInstance*>::const_iterator it = instances.begin(); it != end; ++it) {
+        if (SVGUseElement* element = (*it)->correspondingUseElement()) {
+            ASSERT(element->inDocument());
+            element->invalidateShadowTree();
+        }
+    }
 }
 

trunk/Source/WebCore/svg/SVGUseElement.h

@@ -51 +51 @@
     SVGElementInstance* instanceForShadowTreeElement(Node*) const;
     void invalidateShadowTree();
+    void invalidateDependentShadowTrees();
 
     RenderObject* rendererClipChild() const;