Closed Bug 147938 Opened 22 years ago Closed 22 years ago

Don't Invalidate nsImageFrame area if it's hidden


(Core :: Layout: Images, Video, and HTML Frames, enhancement)

Not set





(Reporter: paper, Assigned: paper)




(Keywords: perf)


(1 file, 1 obsolete file)

When nsImageFrame::FrameChanged is called, and the image frame is visibility:
hidden, we don't need to invalidate.  This saves a lot of calls and reduces CPU

Test Case:

There are 7 hidden animated gifs in the test case.  Without this patch, CPU is
about 25% on my system (PIII-933 on Win2k).  With the patch, CPU is 0%
Attached patch Patch to check if invisible (obsolete) — Splinter Review
I wouldn't mind someone confirming CPU usage on
Include CPU Speed, CPU Usage, OS, Build.
Depends on: 86319
No longer depends on: 86319
Blocks: 94828
I do see about 25% CPU usage on win XP trunk build 2002052908
Ever confirmed: true
Keywords: patch, perf, review
os/2 mozilla rc2 plus privates, 700mhz, 
w/o fix: idle: 56.62%  busy: 41.99%  intr:  1.39%
w/ fix: idle: 78.91%  busy: 20.51%  intr:  0.58%
Blocks: 119597
Keywords: mozilla1.0.1
Comment on attachment 85476 [details] [diff] [review]
Patch to check if invisible

It might be nice to solve this problem more generally.	However, this seems OK
if you think it will help more than it hurts.  (How often are images hidden? 
How long does it take to check the style data?	It probably does...)

>+  const nsStyleVisibility* vis = 
>+        (const nsStyleVisibility*)((nsIStyleContext*)mStyleContext)->GetStyleData(eStyleStruct_Visibility);

Could you use

const nsStyleVisibility* vis;
::GetStyleData(this, &vis);

instead?  You certainly don't need that second cast.
David Baron:  Done.

The whole style casting thing is also done in about 6 other places in
nsImageFrame, and that's why I had it like that originally.  Is there enough
performace inprovements using your method to create another bug to convert
those 6 over?
Attachment #85476 - Attachment is obsolete: true
Comment on attachment 88265 [details] [diff] [review]
Patch to check if invisible

r=dbaron.  It's not a performance issue -- it's a typesafety one.
Attachment #88265 - Flags: review+
Comment on attachment 88265 [details] [diff] [review]
Patch to check if invisible

sr=waterson, nice!
Attachment #88265 - Flags: superreview+
Closed: 22 years ago
Resolution: --- → FIXED
Product: Core → Core Graveyard
Product: Core Graveyard → Core
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