Changeset 103855 in webkit for trunk/Source/WebCore/html/HTMLSelectElement.cpp

Timestamp:

Dec 30, 2011, 6:43:33 PM (13 years ago)

Author:

[email protected]

Message:

Cache and reuse the HTMLSelectElement.options collection.
<​http://webkit.org/b/75399>

Reviewed by Anders Carlsson.

Source/WebCore:

Let HTMLSelectElement::options() cache the returned collection and tie it to the
lifetime of the form. This shrinks HTMLSelectElement by sizeof(CollectionCache)
minus one pointer.

Test: fast/dom/select-options-collection-idempotence.html

fast/gc-9.html

• html/HTMLSelectElement.h:
• html/HTMLSelectElement.cpp:

(WebCore::HTMLSelectElement::options):

Cache the HTMLOptionsCollection returned by options() on the HTMLSelectElement.
Remove the per-select CollectionCache and let the collection manage that.

• html/HTMLOptionsCollection.h:
• html/HTMLOptionsCollection.cpp:

(WebCore::HTMLOptionsCollection::create):
(WebCore::HTMLOptionsCollection::HTMLOptionsCollection):

Tell the base class constructor to not retain the back-pointer to the element.

• html/HTMLSelectElement.cpp:

(WebCore::HTMLSelectElement::setRecalcListItems):

• html/HTMLOptionsCollection.cpp:

(WebCore::HTMLOptionsCollection::invalidateCache):

Added so HTMLSelectElement can invalidate the collection without triggering
unnecessary instantiation of a CollectionCache.

LayoutTests:

• Update gc-9.html to document the new lifetime characteristics of HTMLSelectElement.options.
• Add a test to verify that HTMLSelectElement.options returns the same object when called repeatedly.

• fast/dom/gc-9-expected.txt:
• fast/dom/gc-9.html:
• fast/dom/select-options-collection-idempotence-expected.txt: Added.
• fast/dom/select-options-collection-idempotence.html: Added.

File:

• trunk/Source/WebCore/html/HTMLSelectElement.cpp (modified) (2 diffs)

trunk/Source/WebCore/html/HTMLSelectElement.cpp

@@ -328 +328 @@
 PassRefPtr<HTMLOptionsCollection> HTMLSelectElement::options()
 {
-    return HTMLOptionsCollection::create(this);
+    if (!m_optionsCollection)
+        m_optionsCollection = HTMLOptionsCollection::create(this);
+    return m_optionsCollection;
 }
 
@@ -681 +683 @@
     setOptionsChangedOnRenderer();
     setNeedsStyleRecalc();
-    if (!inDocument())
-        m_collectionInfo.reset();
+    if (!inDocument() && m_optionsCollection)
+        m_optionsCollection->invalidateCache();
 }