1115943 - Lag when quickly shifting through requests with arrow keys

Status: NEW

(DevTools :: Netmonitor, defect)

Description

[Sami Jaktholm]

Steps to reproduce:
1. Open netmonitor
2. Go to a site that makes a lot of request (e.g. http://nytimes.com makes ~220 requests with clean profile)
3. Select the last item and then press and hold "Up" arrow key

What happens:
The UI is slow to update the newly selected request. In worst case the UI stops updating until you release the key or reach the top.

What should happen:
The UI keeps updating although the selected request changes constantly.


Most of the time is spent in _flushWaterfallViews(reset = true) (called from [1]) as it causes all kinds of expensive blocking layout operations to take place. Reset should probably be true only if toggling actually changed the available space.

[1] http://hg.mozilla.org/mozilla-central/file/44344099d119/browser/devtools/netmonitor/netmonitor-view.js#l1836