726347 - [Page Thumbnails] add preference to disable capturing thumbnails in the background

Status: VERIFIED FIXED

(Firefox :: General, defect)

Description

[Mats Palmgren (inactive)]

It's really painful to try to debug anything to do with painting
with thumbnail drawWindow() calls happening every couple of seconds.
I can't find a way to turn this feature off...

I would like a preference, or environment variable, or configure
build option that turns off thumbnails.

Comment 1

[Mats Palmgren (inactive)]

Attachment: temporary hack to "turn it off"

Comment 2

[Mats Palmgren (inactive)]

I have no intention of fixing this myself.

Comment 3

[Ed Morley [:emorley]]

(Sorry was fixing a number of bugs on which people had forgotten to set the assignee, and was going by patch author)

Comment 4

[Tim Taubert [:ttaubert] (inactive)]

Attachment: patch v1

Patch that introduces a pref to disable capturing thumbnails in the background for debugging/profiling purposes.

Comment 5

[Dão Gottwald [:dao]]

Comment on attachment 614060 [details] [diff] [review]
patch v1

We shouldn't sync this. I'm not sure this needs a default value in firefox.js either...

Comment 6

[Tim Taubert [:ttaubert] (inactive)]

Attachment: patch v2

(In reply to Dão Gottwald [:dao] from comment #5)
> We shouldn't sync this. I'm not sure this needs a default value in
> firefox.js either...

Yeah, we should be fine without all that for debugging purposes.

Comment 7

[Dão Gottwald [:dao]]

Comment on attachment 614068 [details] [diff] [review]
patch v2

getBoolPref will throw now, which you'll need to catch.

Comment 8

[Tim Taubert [:ttaubert] (inactive)]

Attachment: patch v3

(In reply to Dão Gottwald [:dao] from comment #7)
> getBoolPref will throw now, which you'll need to catch.

Right...

Comment 9

[Dão Gottwald [:dao]]

Comment on attachment 614076 [details] [diff] [review]
patch v3

What's the point of the extra method? This should be sufficient:

try {
  if (Services.prefs.getBoolPref(this._prefCapturingDisabled))
    return;
} catch (e) {}

You don't really need this._prefCapturingDisabled either...

Comment 10

[Tim Taubert [:ttaubert] (inactive)]

Attachment: patch v4

Comment 11

[Tim Taubert [:ttaubert] (inactive)]

https://hg.mozilla.org/integration/fx-team/rev/51fe735d19a9

Comment 12

[Girish Sharma [:Optimizer]]

If I set it off, then my new tab page thumbnails will never update? (or not show at all if there isn't one before the disabling of the pref)

Comment 13

[Tim Taubert [:ttaubert] (inactive)]

Exactly.

Comment 14

[Tim Taubert [:ttaubert] (inactive)]

https://hg.mozilla.org/mozilla-central/rev/51fe735d19a9

Comment 15

[Tim Taubert [:ttaubert] (inactive)]

Comment on attachment 614085 [details] [diff] [review]
patch v4

[Approval Request Comment]
Risk to taking this patch (and alternatives if risky): very low risk, tiny patch
String changes made by this patch: none

I think we should backport this patch for Fx 12 and set the new preference to true - to disable capturing thumbnails at all. The thumbnail service is active in Fx 12 but there's not a single piece of code using it. We have patches for Fx 13/14 that will minimize the performance impact of this service but I think it doesn't make sense to backport them to 12.

If users change their prefs to test the early version of about:newtab in Fx 12 they might as well flip this pref to have thumbnails captured.

Comment 16

[Alex Keybl [:akeybl]]

Comment on attachment 614085 [details] [diff] [review]
patch v4

[Triage Comment]
The only reason to approve this for Beta 12 would be due to debug pain noted in comment 0. Since that was first noted 2 months ago, it's obviously not that painful. Let's leave things as is.

Comment 17

[Virgil Dicu [:virgil] [QA]]

Mozilla/5.0 (X11; Linux i686; rv:14.0) Gecko/20120424 Firefox/14.0a1

Verified manually on latest Nightly. no thumbnails are captured for newly visited pages if the pref ("browser.pagethumbnails.capturing_disabled") is set to true.

verified on Ubuntu 11.10, Mac OS 10.6, Windows 7.

Comment 18

[Jim Jeffery not reading bug-mail 1/2/11]

(In reply to Virgil Dicu [:virgil] [QA] from comment #17)
> Mozilla/5.0 (X11; Linux i686; rv:14.0) Gecko/20120424 Firefox/14.0a1
> 
> Verified manually on latest Nightly. no thumbnails are captured for newly
> visited pages if the pref ("browser.pagethumbnails.capturing_disabled") is
> set to true.
> 
> verified on Ubuntu 11.10, Mac OS 10.6, Windows 7.

This is a 'hidden' pref, i.e. has to be manually added ?

Comment 19

[Tim Taubert [:ttaubert] (inactive)]

Yes, you have to create it yourself as a boolean with the value 'true'.

Comment 20

[CruNcher]

will this automatically delete the already created thumbnails after restart in the new thumb place or is it needed to do that manually ?

Comment 21

[Tim Taubert [:ttaubert] (inactive)]

This will only prevent new thumbnails from being created. Existing ones can be deleted by clearing all your browsing history or removing the "thumbnails" directory from your profile.

Comment 22

[asukacharming]

Attachment: Thumbnails

Comment 23

[Jim Jeffery not reading bug-mail 1/2/11]

Adding the pref and enabling does stop the storage of new thumbnails, but ...

New folders are being created every day or even more often.
Since adding the pref looking at the Properties of the Thumbnails Folder on Win7 x64
0 Files, 256 Folders

Setting the pref to true should also prevent the creation of additional useless folders.  

Should a new bug be filed to prevent the creation of 'Empty Folder' (s) ?

Comment 24

[Virtual_ManPL [:Virtual] 🇵🇱 - (please needinfo? me - so I will see your comment/reply/question/etc.)]

Is there any reason why this preference in hidden in about:config ?

Comment 25

[dickvl]

The MDN doc page of the browser.pagethumbnails.capturing_disabled pref shows the wrong meaning of this pref.

https://developer.mozilla.org/en-US/docs/Mozilla/Preferences/Preference_reference/browser.pagethumbnails.capturing_disabled

true (default)
    The application creates screenshots of visited web pages.
false
    The application doesn't create screenshots of visited web pages.

Comment 26

[Tim Taubert [:ttaubert] (inactive)]

(In reply to dickvl from comment #25)
> The MDN doc page of the browser.pagethumbnails.capturing_disabled pref shows
> the wrong meaning of this pref.

Thanks for noticing! I just fixed the documentation.

Comment 28

[Robin A. Meade]

Can we have this unhidden? There are reasons for not wanting thumbnails generated that go beyond testing purposes.

Bug 1551132 can't be fixed until this is unhidden.