1592637 - [popup] Lazyload link.js in Description.js

Status: RESOLVED FIXED

(DevTools :: Performance Tools (Profiler/Timeline), enhancement, P3)

Description

[Julien Wajsberg [:julienw]]

In Description.js, we load link.js unconditionally, but it's really only used when the user clicks a link. We should lazyload it.
It's important because link.js itself loads more scripts, that shouldn't be in the critical path when loading up the popup.

Comment 1

[Julien Wajsberg [:julienw]]

I saw this from this profile shared to me by Florian: https://profiler.firefox.com/public/affdf3f0c3c71a3c9b955d0692836ef16165b092/marker-chart/?globalTrackOrder=0-1-2-3-4-5&hiddenGlobalTracks=1-2-3-4-5&hiddenLocalTracksByPid=18612-1-2-3-4~4500-1&localTrackOrderByPid=18612-5-6-0-1-2-3-4~17960-0~2656-0~14228-0~21388-0~4500-2-0-1~&range=19.4011_25.5384~23.8088_25.5384~23.8088_24.8010&thread=0&v=4

Comment 2

[Jacob Stenson]

Hi there. I would like to take on this bug. From what I gather from your description I would need to move the defintion of "openDocLink" inside the "handleLinkClick" event function so it is not in the critical path of the file? As this is the only place "openDocLink" is used in the description.js file? Thanks

Comment 3

[Julien Wajsberg [:julienw]]

Hey Jacob,
Yes, exactly this!

This is used in the new performance panel, when it's shown in the devtools toolbox. So to test it you can:

1. enable the "experimental" performance panel, from devtools' settings.
2. open the "Performance" tab in the devtools
   => The "Description" item is what is shown at the bottom of this view. There you can see if clicking on links still works.

Thanks Jacob! Assigning the bug to you, then :)

Comment 4

[Julien Wajsberg [:julienw]]

Attachment: screenshot of the performance panel

Comment 5

[Julien Wajsberg [:julienw]]

Actually this bit isn't even displayed in the popup, so it's even more absurd that it gets in the way of the popup. Maybe the Description component itself should be lazy-loaded in Perf.js, but I'd bet it's less important for the performance because it's a very small component with no additional dependency (once this bug is fixed).

Comment 6

[Jacob Stenson]

Hi again. I believe I have solved the bug. After moving the code outside of the critical path and into the handleLinkClick function and testing it, the links in the experimental performance panel are still functional.

Comment 7

[Jacob Stenson]

Attachment: Bug 1592637 - [popup] Lazyload link.js in Description.js, r=julienw

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ca19f048cd8d
[popup] Lazyload link.js in Description.js, r=julienw

Comment 9

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/ca19f048cd8d