GlobalContributions: Fetch correct byte count for each local wiki revision
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Authored By

	Msz2001
	Feb 1 2025, 7:10 PM

Description

Steps to replicate the issue (include links if applicable):

Navigate to eg. https://meta.wikimedia.org/wiki/Special:GlobalContributions/Msz2001
Find an edit from outside of metawiki, eg. 1 Feb at 16:21 UTC on page User_talk:Msz2001 at pl.wikimedia.org
Compare its change in size with one reported on https://pl.wikimedia.org/wiki/?curid=12145&action=history

What happens?:
GlobalContributions reports that this edit was (+10,273), even though actually it was (-1). 10kB is the page size after the change. That's interesting especially that one entry below, the previous edit is listed, so that it's not an issue of going beyond a limit of edits selected by some database query.

What should have happened instead?:
The delta size should be the same on GlobalContributions and on local wiki

Software version (on Special:Version page; skip for WMF-hosted wikis like Wikipedia):

Other information (browser name/version, screenshots, etc.):
The edits made on meta are reported with good edit size deltas.

(dates on the screenshot are in UTC+1)

Details

Related Changes in Gerrit:

	Subject	Repo	Branch	Lines +/-
	GlobalContributions: Fetch correct byte count for revisions	mediawiki/extensions/CheckUser	master	+164 -17
	ContributionsPager: Allow customizing parent rev len fetching	mediawiki/core	master	+10 -4

Customize query in gerrit

Related Objects

Duplicates Merged Here: T393441: Global contributions page provides incorrect information as page size difference
T390601: Total page size showing instead of the diff of bytes
T390486: GlobalContributions: Inaccurate added/removed bytes for Wikidata edits

Event Timeline

Msz2001 created this task.Feb 1 2025, 7:10 PM

Restricted Application added a project: Trust and Safety Product Team. · View Herald TranscriptFeb 1 2025, 7:10 PM

Restricted Application added a subscriber: Aklapper. · View Herald Transcript

A_smart_kitten subscribed.Feb 1 2025, 7:14 PM

It needs previous revision of every edit but they are not get.
includes/pager/ContributionsPager.php:doBatchLookups from MediaWiki does not fill previd because tryCreatingRevisionRecord prevents doing this in this case. I think it is not necessary to do this way, because getting superior revisions don't need RevisionRecord created. So, this code can be changed or overwrite method GlobalContributionsPager with this part (getRevisionSizes).

Johannnes89 subscribed.Feb 2 2025, 7:45 PM

Nintendofan885 subscribed.Feb 17 2025, 2:43 AM

1AmNobody24 subscribed.Feb 21 2025, 8:15 AM

This seems like an important bug to fix, so moving into the current sprint. We could move it into the next sprint if we don't have time.

Vermont subscribed.Mar 5 2025, 8:08 PM

kostajh moved this task from Priority Backlog to Ready on the Trust and Safety Product Sprint (Sprint Lemon Meringue (March 3 - 21)) board.Mar 14 2025, 1:13 PM

Tchanders moved this task from Backlog to Triaged on the CheckUser-GlobalContributions board.Mar 14 2025, 1:32 PM

Ponor subscribed.Mar 16 2025, 5:28 AM

kostajh renamed this task from Special:GlobalContributions reports wrong edit size delta to GlobalContributions: Fetch correct size for each local wiki revision.Mar 17 2025, 10:28 AM

• mszabo changed the task status from Open to In Progress.Mar 18 2025, 12:43 PM

• mszabo claimed this task.

• mszabo moved this task from Ready to In Progress on the Trust and Safety Product Sprint (Sprint Lemon Meringue (March 3 - 21)) board.

ClydeFranklin subscribed.Mar 20 2025, 8:11 PM

Tchanders edited projects, added Trust and Safety Product Sprint (Sprint Chocolate Cake (March 24 - April 11)); removed Trust and Safety Product Sprint (Sprint Lemon Meringue (March 3 - 21)).Mar 24 2025, 2:20 PM

Tchanders moved this task from Priority Backlog to In Progress on the Trust and Safety Product Sprint (Sprint Chocolate Cake (March 24 - April 11)) board.

Count_Count subscribed.Mar 28 2025, 11:42 AM

A_smart_kitten merged a task: T390486: GlobalContributions: Inaccurate added/removed bytes for Wikidata edits.Mar 30 2025, 7:06 PM

A_smart_kitten added a subscriber: Toadette.

Dylsss merged a task: T390601: Total page size showing instead of the diff of bytes.Mar 31 2025, 6:43 PM

Dylsss added a subscriber: Nadzik.

Dreamy_Jazz moved this task from Inbox to Engineering on the Trust and Safety Product Team board.Apr 3 2025, 11:41 AM

Nemoralis subscribed.Apr 3 2025, 8:40 PM

aliu subscribed.Apr 3 2025, 8:41 PM

kostajh renamed this task from GlobalContributions: Fetch correct size for each local wiki revision to GlobalContributions: Fetch correct byte count for each local wiki revision.Apr 4 2025, 12:41 PM

Indeed, it seems that for most (or all?) revisions, the absolute size is mistaken for the relative size difference.

This means a lot of attention is drawn to seemingly minor edits.

This cause makes sense in so far that this backed by a revision table query, and the revision only knows its own size. The "difference" in size, just like the diff in text, are purely runtime concepts, and may change over time (e.g. when revisions are imported/archived/restored; or when pages have their history merged/split).

In core, this works because ContributionsPager::doBatchLookups performs a second query that warms up mParentLens via a batched RevisionStore->getRevisionSizes() call.

https://meta.wikimedia.org/wiki/Special:GlobalContributions/Krinkle
https://www.mediawiki.org/wiki/Special:Contributions/Krinkle

Screenshot 2025-04-10 at 15.24.48.png (1×2 px, 1 MB)

XtexChooser subscribed.Apr 13 2025, 6:55 AM

kostajh edited projects, added Trust and Safety Product Sprint (Sprint Cozonac (April 14 - May 2)); removed Trust and Safety Product Sprint (Sprint Chocolate Cake (March 24 - April 11)).Apr 14 2025, 2:52 PM

kostajh moved this task from Priority Backlog to In Progress on the Trust and Safety Product Sprint (Sprint Cozonac (April 14 - May 2)) board.

kostajh edited projects, added Trust and Safety Product Sprint (Sprint Key Lime Pie (May 5 - May 23)); removed Trust and Safety Product Sprint (Sprint Cozonac (April 14 - May 2)).May 5 2025, 6:50 AM

kostajh moved this task from Priority Backlog to In Progress on the Trust and Safety Product Sprint (Sprint Key Lime Pie (May 5 - May 23)) board.

kostajh merged a task: T393441: Global contributions page provides incorrect information as page size difference.May 6 2025, 9:31 AM

kostajh added a subscriber: Ankry.

STran moved this task from Triaged to In Progress on the CheckUser-GlobalContributions board.May 6 2025, 9:33 AM

STran added a project: Temporary accounts (Major pilot wiki deployment).May 8 2025, 11:32 AM

IKhitron awarded a token.May 11 2025, 4:03 PM

IKhitron subscribed.

Change #1145147 had a related patch set uploaded (by Máté Szabó; author: Máté Szabó):

[mediawiki/core@master] ContributionsPager: Allow customizing parent rev len fetching

https://gerrit.wikimedia.org/r/1145147

gerritbot added a project: Patch-For-Review.May 13 2025, 11:09 AM

Change #1145148 had a related patch set uploaded (by Máté Szabó; author: Máté Szabó):

[mediawiki/extensions/CheckUser@master] GlobalContributions: Fetch correct byte count for revisions

https://gerrit.wikimedia.org/r/1145148

• mszabo moved this task from In Progress to Needs Review on the Trust and Safety Product Sprint (Sprint Key Lime Pie (May 5 - May 23)) board.May 13 2025, 11:55 AM

Tchanders moved this task from Backlog to In progress on the Temporary accounts (Major pilot wiki deployment) board.May 13 2025, 12:30 PM

Change #1145147 merged by jenkins-bot:

[mediawiki/core@master] ContributionsPager: Allow customizing parent rev len fetching

https://gerrit.wikimedia.org/r/1145147

ReleaseTaggerBot added a project: MW-1.45-notes (1.45.0-wmf.2; 2025-05-20).May 13 2025, 5:00 PM

Tchanders moved this task from Needs Review to Needs QA on the Trust and Safety Product Sprint (Sprint Key Lime Pie (May 5 - May 23)) board.May 13 2025, 5:11 PM

Change #1145148 merged by jenkins-bot:

[mediawiki/extensions/CheckUser@master] GlobalContributions: Fetch correct byte count for revisions

https://gerrit.wikimedia.org/r/1145148

Maintenance_bot removed a project: Patch-For-Review.May 13 2025, 6:30 PM

QA is completed, I have verified the new code has been implemented and is functioning as expected (The delta size is the same on GlobalContributions and on local wiki).

kostajh closed this task as Resolved.May 23 2025, 9:38 AM

	F59032065: Screenshot 2025-04-10 at 15.24.48.png
	Apr 10 2025, 2:35 PM

GlobalContributions: Fetch correct byte count for each local wiki revisionClosed, ResolvedPublicBUG REPORTActions

Description

Details

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Event Timeline

GlobalContributions: Fetch correct byte count for each local wiki revision
Closed, ResolvedPublicBUG REPORT
Actions