Bug 102617
| Summary: | Add a 'has flipped blocks' bit somewhere to optimize stuff | ||
|---|---|---|---|
| Product: | WebKit | Reporter: | Simon Fraser (smfr) <simon.fraser> |
| Component: | Layout and Rendering | Assignee: | alan <zalan> |
| Status: | RESOLVED FIXED | ||
| Severity: | Normal | CC: | dbates, hyatt, kling, koivisto, leviw, nduca, ojan, psolanki, sabouhallawa, simon.fraser, zalan |
| Priority: | P2 | ||
| Version: | 528+ (Nightly build) | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
Simon Fraser (smfr)
canMapBetweenRenderers() has to walk renderers looking for flipped blocks, which is unfortunate because this slows down the layer->layer mapping optimization there.
A bit on RenderLayer that says "hasFlippedBlocks contents" would help.
| Attachments | ||
|---|---|---|
| Add attachment proposed patch, testcase, etc. |
Simon Fraser (smfr)
I also note that RenderBox::topLeftLocationOffset() is expensive, about 2% of the total time when scrolling a layer-heavy page. If we could do a quick check for flipped blocks, we could probably avoid the containingBlock() call and make it much faster.
Dave Hyatt
I added this, so this bug can be closed.