Bug 78132 – [WK2] Performance issue in FindController::findString

• Component: WebKit2
• Status: RESOLVED FIXED

[Sergio Villar Senin]

Search for the previous or next occurrence of a given string is a quite common operation in a Web browser (or any other WebKit embedder). If I'm not wrong this operation is currently heavier than it should be in WK2. That's because FindController::findString unconditionally calls unmarkAllTextMatches(). So, if FindOptionsShowOverlay is passed (or FindOptionsShowHighlight once http://webkit.org/b/76522 lands), the ::findString() method will _always_ unmarkAllTextMatches() and markAllTextMatchesForText(). That's fine if the text to search is different, but if we're doing search_next(), search_previous() kind of operations, i.e. the string to search is the same, we will be unnecessary unmarking and marking all text matches everytime we look for the next/previous result.

[Sergio Villar Senin]

As far as I see this, if it's considered an issue, the only way to fix this would be to save the last find operation parameters in the FindController to avoid unmarkAll+markAll if the following find operation has the same string, options and matchCount. Obviously that state will have to be cleared in ::hideFindUI.

[Sergio Villar Senin]

Created attachment 129838 [details]
Tentative patch

[WebKit Review Bot]

Thanks for the patch. If this patch contains new public API please make sure it follows the guidelines for new WebKit2 GTK+ API. See http://trac.webkit.org/wiki/WebKitGTK/AddingNewWebKit2API

[Sergio Villar Senin]

So the approach I followed is:

1) unmarkAllTextMatches() is not called by default
2) it'd be called from FindController whenever:
   a) the string is not found
   b) we're going to call markAllTextMatches()
3) clients could perform searchNext()/searchPrevious() kind of operations by just calling FindString with the same arguments BUT removing the showOverlay & showHighlight options from the findOptions.

PS: I know it might require a test but just wanted to confirm that the approach is correct.
PS2: didn't find any usage of WebPageProxy::findString in the other ports... sounds weird

[Carlos Garcia Campos]

Comment on attachment 129838 [details]
Tentative patch

Looks good to me

[Tim Horton]

Comment on attachment 129838 [details]
Tentative patch

View in context: https://bugs.webkit.org/attachment.cgi?id=129838&action=review

> Source/WebKit2/UIProcess/API/gtk/WebKitFindController.cpp:357
> +        // highlighting. Since most of them (all?) where using that

s/where/were/? Though I see you're just moving the comment, might as well fix it while you're here.

[Sergio Villar Senin]

(In reply to comment #6)
> (From update of attachment 129838 [details])
> View in context: https://bugs.webkit.org/attachment.cgi?id=129838&action=review
> 
> > Source/WebKit2/UIProcess/API/gtk/WebKitFindController.cpp:357
> > +        // highlighting. Since most of them (all?) where using that
> 
> s/where/were/? Though I see you're just moving the comment, might as well fix it while you're here.

Sure I will. Anyone willing to review the patch? Or any comment to the approach I followed?

[Sergio Villar Senin]

This patch is 4 months old. Any comment or review?

[WebKit Review Bot]

Comment on attachment 129838 [details]
Tentative patch

Rejecting attachment 129838 [details] from commit-queue.

Failed to run "['/mnt/git/webkit-commit-queue/Tools/Scripts/webkit-patch', '--status-host=queues.webkit.org', '-..." exit_code: 2

Last 500 characters of output:
 Source/WebKit2/UIProcess/API/gtk/WebKitFindController.cpp
patching file Source/WebKit2/WebProcess/WebPage/FindController.cpp
Hunk #1 succeeded at 152 with fuzz 1 (offset 61 lines).
Hunk #2 FAILED at 98.
Hunk #3 FAILED at 115.
2 out of 3 hunks FAILED -- saving rejects to file Source/WebKit2/WebProcess/WebPage/FindController.cpp.rej

Failed to run "[u'/mnt/git/webkit-commit-queue/Tools/Scripts/svn-apply', u'--force', u'--reviewer', u'Anders Car..." exit_code: 1 cwd: /mnt/git/webkit-commit-queue/

Full output: http://queues.webkit.org/results/13180043

[Carlos Garcia Campos]

Committed r122428: <http://trac.webkit.org/changeset/122428>