Bug 82681

Summary: NodeRareData::m_treeScope should be lazily retrieved
Product: WebKit Reporter: Hajime Morrita <morrita>
Component: DOMAssignee: Hajime Morrita <morrita>
Status: RESOLVED WONTFIX    
Severity: Normal CC: dglazkov, dominicc, rniwa, shinyak
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
Bug Depends on: 82701    
Bug Blocks: 87034    
Attachments:
Description Flags
WIP none

Hajime Morrita
Reported 2012-03-29 17:28:30 PDT
Currently we set it when a node is inserted into a tree. But it lets all nodes behind shadow to have NodeRareData. That means it no longer "rare". In reality, NodeRareData::m_treeScope is a kind of a cash. So we don't maintain it eagerly. It can be lazily retrieved. This is an alternative of Bug 59816 which aimed to make TreeScope management saner and performant.
Attachments
WIP (25.64 KB, patch)
2012-03-30 00:27 PDT, Hajime Morrita 		no flags
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Hajime Morrita
Comment 1 2012-03-30 00:27:39 PDT
Created attachment 134738 [details] WIP
Elliott Sprehn
Comment 2 2012-12-06 09:50:35 PST
Comment on attachment 134738 [details] WIP View in context: https://bugs.webkit.org/attachment.cgi?id=134738&action=review > Source/WebCore/dom/Node.cpp:446 > +TreeScope* Node::treeScope(TreeScopeStoreCacheType scoreCache) const If we took this approach I think you'd need some kind of DirtyTreeScope bit field in node otherwise you're going to cause rare data on every node we call treeScope() on, ex. during event dispatch, and you're also going to introduce this tree walk for treeScope() into all existing pages even ones that don't use Shadow DOM so treeScope gets much slower.
Hajime Morrita
Comment 3 2012-12-06 21:44:56 PST
(In reply to comment #2) > If we took this approach I think you'd need some kind of DirtyTreeScope bit field in node otherwise you're going to cause rare data on every node we call treeScope() on, ex. during event dispatch, and you're also going to introduce this tree walk for treeScope() into all existing pages even ones that don't use Shadow DOM so treeScope gets much slower. Yes, this approach looks inferior than replacing document pointer. We need to inspect each treeScope() call to decide which (slow-clean or fast-caching) we should use. That isn't what we want. This bug was just a result of exploration for attacking slow-treeScope problem.
Dominic Cooney
Comment 4 2013-01-10 06:09:14 PST
Since r138735 m_treeScope is in Node. So I believe this is fixed.
Ryosuke Niwa
Comment 5 2013-01-10 09:09:44 PST
It's probably better to close this with WONTFIX since this bug no longer applies to ToT WebKit.
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