Bug 43085
| Summary: | libxml2 parser has a large performance overhead | ||
|---|---|---|---|
| Product: | WebKit | Reporter: | Patrick R. Gansterer <paroga> |
| Component: | XML | Assignee: | Nobody <webkit-unassigned> |
| Status: | NEW | ||
| Severity: | Normal | CC: | annulen, ap, darin, eric, mrowe |
| Priority: | P2 | ||
| Version: | 528+ (Nightly build) | ||
| Hardware: | All | ||
| OS: | All | ||
| Bug Depends on: | 45735, 52036, 41427, 45488, 45594, 45990, 50516, 50517 | ||
| Bug Blocks: | |||
Patrick R. Gansterer
In the current implementation of the XMLParser is much room for performance improvements.
A expat based XMLParser (see bug 41427) showed up to 25% less parsing time:
libxml2 expat percent
5MB SVG: 0.7183sec 0.5356sec -25%
10MB SVG: 1.6084sec 1.2298sec -24%
20MB SVG: 5.4084sec 4.6952sec -13%
| Attachments | ||
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| Add attachment proposed patch, testcase, etc. |
Eric Seidel (no email)
Long ago we used Expat. I don't remember why we switched to libxml2.
Patrick R. Gansterer
(In reply to comment #1)
> Long ago we used Expat. I don't remember why we switched to libxml2.
because expat has no XLST support?
Eric Seidel (no email)
If you're interested in this question, I suggest reading the svn logs in the xml directory in webcore. Trac.webkit.org.
Patrick R. Gansterer
(In reply to comment #3)
> If you're interested in this question, I suggest reading the svn logs in the xml directory in webcore. Trac.webkit.org.
Wow, that's realy old code. ;-)
I don't think that expat will be better than libxml. IMHO only a "native" WebKit parser can avoid the time-consuming memcpy/strcpy that any 3rdparty parser has. My expat implementation avoids the UTF16->UTF8->UTF16 conversation of libxml implementation, but there are unnecessary memcpy in the expat code anyway.
Konstantin Tokarev
>IMHO only a "native" WebKit parser can avoid the time-consuming memcpy/strcpy that any 3rdparty parser has.
Rapidxml does not have any memcpy/strcpy calls
Patrick R. Gansterer
(In reply to comment #5)
> >IMHO only a "native" WebKit parser can avoid the time-consuming memcpy/strcpy that any 3rdparty parser has.
>
> Rapidxml does not have any memcpy/strcpy calls
Rapidxml (like expat) has many missing features: e.g. namespace support. So it's not a real alternative for libxml2.