1933104 - Message list tree can waste a significant amount of time creating rows that are never seen

Status: RESOLVED FIXED

(Thunderbird :: Folder and Message Lists, defect)

Description

[Geoff Lankow (:darktrojan) [OOO, back 21 July]]

If a new message is added to the top of the message list, all of the visible and just-off-screen rows are redrawn to reflect the message now in those positions (as the messages are now all one row lower). If lots of new messages are added to the top of the message list individually, all of the visible and just-off-screen rows are redrawn for every single added message. This is a huge waste of processing time, especially as the redrawing isn't exactly fast.

I think what we should do is have the rows update at most once per frame, which is still a lot more frequently than humans can see, but dramatically reduces the work done. If the data for any particular row is updated more than once during that time, only the most recent data will be used. The downside is that the rows won't be updated instantly and that will annoy tests (and test writers). It's a price worth paying, I think.

Comment 1

[Geoff Lankow (:darktrojan) [OOO, back 21 July]]

Attachment: Bug 1933104 - Update tree-view rows at most once per frame. r=#thunderbird-reviewers

Comment 2

[Wayne Mery (:wsmwk)]

Sounds like this might be one of the severe issues affecting 115 and 128 users getting new messages?

Comment 3

[Geoff Lankow (:darktrojan) [OOO, back 21 July]]

Maybe? 🤷‍♂️

The one circumstance I describe on Phabricator with this patch, certainly. But that does involve a lot of messages appearing all at once, which I wouldn't expect many people to see regularly.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/comm-central/rev/b0dd186860dd
Update tree-view rows at most once per frame. r=aleca,mkmelin

Comment 5

[Corey Bryant]

Geoff, is this ready for beta uplift?

Comment 6

[Geoff Lankow (:darktrojan) [OOO, back 21 July]]

Comment on attachment 9439610 [details]
Bug 1933104 - Update tree-view rows at most once per frame. r=#thunderbird-reviewers

[Approval Request Comment]
Regression caused by (bug #): supernova
User impact if declined: message list could slow everything down if many updates happened at once
Testing completed (on c-c, etc.): a week on central
Risk to taking this patch (and alternatives if risky): has the potential to make a big mess, but I think the risk is low

Comment 7

[Corey Bryant]

Comment on attachment 9439610 [details]
Bug 1933104 - Update tree-view rows at most once per frame. r=#thunderbird-reviewers

[Triage Comment]
Approved for beta

Comment 8

[Rob Lemley [:rjl]]

Thunderbird 134.0b3:
https://hg.mozilla.org/releases/comm-beta/rev/0ae9312b4c99

Comment 9

[Geoff Lankow (:darktrojan) [OOO, back 21 July]]

Comment on attachment 9439610 [details]
Bug 1933104 - Update tree-view rows at most once per frame. r=#thunderbird-reviewers

[Approval Request Comment]
Regression caused by (bug #): supernova
User impact if declined: message list could slow everything down if many updates happened at once
Testing completed (on c-c, etc.): a week on central and a week on beta – this shouldn't be on ESR before 128.6 so that'll give it a full month on beta
Risk to taking this patch (and alternatives if risky): has the potential to make a big mess, but I think the risk is low

Comment 10

[Corey Bryant]

Comment on attachment 9439610 [details]
Bug 1933104 - Update tree-view rows at most once per frame. r=#thunderbird-reviewers

[Triage Comment]
Approved for esr128

Comment 11

[Daniel Darnell [:dandarnell]]

Thunderbird 128.6.0esr:
https://hg.mozilla.org/releases/comm-esr128/rev/4eeb435afbaa