2011-01-28 Eric Seidel <eric@webkit.org>
Reviewed by Darin Adler.
HTML5 TreeBuilder regressed a Peacekeeper DOM test by 40%
https://bugs.webkit.org/show_bug.cgi?id=48719
It's unclear exactly what the Peacekeeper benchmark is testing,
because I haven't found a way to run it myself.
However, I constructed a benchmark which shows at least one possible slow point.
The HTML5 spec talks about creating a new document for every time we use
the fragment parsing algorithm. Document() it turns out, it a huge bloated
mess, and the constructor and destructor do a huge amount of work.
To avoid constructing (or destructing) documents for each innerHTML call,
this patch adds a shared dummy document used by all innerHTML calls.
* benchmarks/parser/tiny-innerHTML.html: Added.
2011-01-28 Eric Seidel <eric@webkit.org>
Reviewed by Darin Adler.
HTML5 TreeBuilder regressed a Peacekeeper DOM test by 40%
https://bugs.webkit.org/show_bug.cgi?id=48719
It's unclear exactly what the Peacekeeper benchmark is testing,
because I haven't found a way to run it myself.
However, I constructed a benchmark which shows at least one possible slow point.
The HTML5 spec talks about creating a new document for every time we use
the fragment parsing algorithm. Document() it turns out, it a huge bloated
mess, and the constructor and destructor do a huge amount of work.
To avoid constructing (or destructing) documents for each innerHTML call,
this patch adds a shared dummy document used by all innerHTML calls.
This patch brings us from 7x slower than Safari 5 on tiny-innerHTML
to only 1.5x slower than Safari 5. I'm sure there is more work to do here.
Saving a shared Document like this is error prone. Currently
DummyDocumentFactory::releaseDocument() calls removeAllChildren()
in an attempt to clear the Document's state. However it's possible
that that call is not sufficient and we'll have future bugs here.
* html/parser/HTMLTreeBuilder.cpp:
(WebCore::DummyDocumentFactory::createDummyDocument):
(WebCore::DummyDocumentFactory::releaseDocument):
(WebCore::HTMLTreeBuilder::FragmentParsingContext::FragmentParsingContext):
(WebCore::HTMLTreeBuilder::FragmentParsingContext::document):
(WebCore::HTMLTreeBuilder::FragmentParsingContext::finished):
* html/parser/HTMLTreeBuilder.h:
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@77050
268f45cc-cd09-0410-ab3c-
d52691b4dbfc