#2375: Aweful performance on CJK webpage font rendering
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Reporter: YChao | Owner: behdad
Type: defect | Status: new
Priority: high | Milestone: First Deployment, V1.0
Component: web browser | Version:
Resolution: | Keywords: CJK font browser
Verified: 0 |
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Comment(by YChao):
Replying to [comment:8 sayamindu]:
> Maybe http://www.gnome.org/~federico/news-2007-10.html#pango-cjk-1 has
got something to do with this ?
Yes, indeed I've discussed with Albert Cahalan on devel at laptop.org about
the tiny 256 char cache in Cairo before. Just I have no idea how much
memory would be needed to increase the cache. According to the link, it
seems not very costy. (this should be for Simplified Chinese) You can
refer to this page for a study on Chinese characters frequency in
articles. (in Traditional Chinese)
http://www.edu.tw/EDU_WEB/EDU_MGT/MANDR/EDU6300001/allbook/pin/biau1.htm?open
You can see first 150 characters covers up to 42.6% of typical articles.
Others characters would be quite distinct as a nature of Chinese. The
first 2.2K Traditional Characters covers 97% while it's ~2.0K in
Simplified Chinese. The most popular encoding prior Unicode in Traditional
Chinese, Big5, has 5.4K frequent used characters and 7.6K less frequent
ones. As to GBK for Simplified Chinese, it's of about 3.8K frequent and 3K
less frequent ones. For Japanese, as I remember, it's about 2~3K frequent
used Characters and another ~3K less frequent ones.
However, it would be a better solution which current official Firefox
builds adopt. They have much better performance in CJK than Fedora
packages do. Cache may not work well depending on the displayed content
and you still need to wait foe once. For most CJK user of Fedora or
Ubuntu, the common dirty hack is to disable PANGO for Firefox which would
not be a good solution here.
I'll also try some study on characters count of typical web pages and
report back.
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Ticket URL: <https://dev.laptop.org/ticket/2375#comment:10>
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