Add total number of waiting strings within a locale from /locale/slug/default

[tobifjellner]

[5955] froze the number of waiting strings for each locale, since the query for count of waiting strings in each language used to time out.
At the same time, partial results seems to cached, so if I reloaded Earlier ​https://translate.wordpress.org/stats was showing (or trying to show, the query timed out all the time) the total number of waiting strings per locale.

However, this piece of information is important. First of all for the GTE's of each locale.
I suggest that the total number of waiting strings for a specific locale is added to ​https://translate.wordpress.org/locale/slug/default (where slug is replaced by the locale slug)

Since I hope the count of waiting strings for only ONE locale is a much smaller effort than gathering the same for ALL locales, this should be doable. After all: in order to show correct pagination for the page with waiting projects, a query is already run on that page, to gather all projects with waiting strings and even sort them in descending order by number waiting strings.)

(Updated description on Jan 16 2019 - and reverted prio to Normal)

[ocean90]

We can’t add caching to something if the query itself times out. This also only affects waiting strings for all plugins and themes. The waiting strings for the main projects are still displayed.

[tobifjellner]

In that case we should delete the current columnn with "total waiting strings". As it stands now, it presents stale data that to some extent was incorrect from the start.

And adding this information per locale on the page for each locale shouldn't really time out, since you'll be traversing the data only for one locale.
After all, part of that information is anyway gathered in order to build ​https://translate.wordpress.org/locale/slug/default
Number of projects is used for pagination. Number of waiting strings is presented per project and is used for sorting. We'd just need to present this piece of information. It could, for example, be added next to the breadcrumb, as "Locales / Swedish / Waiting (3168 strings in 92 projects)"

[xavivars]

In the case of Catalan, data is not only stale, but incorrect. Last time I checked (July/August), there were +10k waiting strings (I moved it down from 15k to 10k during the summer). So clearly 12 strings is incorrect :)

[jyourstone]

Seconding this, having the amount of waiting strings displayed is very useful for GTE's to see progress.

[Mte90]

This page for the GWTD will be very helpful we need to track what will happen on that day...

[tobifjellner]

Since this ticket was created, the number of waiting strings in /stats refers only to the projects that are included in the /stats page, i.e. mainly /meta projects.

But this ticket is still very valid: It would be very good to be able to see the total number of waiting strings for your own locale. That can help the team to keep track during an effort to work through a huge backlog, for instance. (I know it inspired us in the Swedish team when we slashed more that 30k strings in less than 2 months.)

[dd32]

In 9711:

Translate: Restore the Waiting Counts for Plugins/Themes as their own columns.

The column values are updated twice daily on a cron.

Fixes #3155.

[tobifjellner]

Thank you a lot, @dd32
This will help some locale teams in setting their goals!

[dd32]

In 9713:

Translate: When the query times out, don't overwrite the old cached data.

See #3155.

[dd32]

In 9720:

Translate: Move the stats generation for /stats from the Stats screen router to the Custom Stats plugin, store the data in the project translation status table rather than the options.

This also avoids the query-timeout problems by running the query as a INSERT INTO ... SELECT FROM which should be more resiliant to timeouts.

See #3155.