Make cache in wp_count_posts persistent

[spacedmonkey]

Current there is a cache in wp_count_posts function. See

        $cache_key = _count_posts_cache_key( $type, $perm );

        $counts = wp_cache_get( $cache_key, 'counts' );

As this use the counts cache group, this cache does not persistent between page requests. However the SQL query that is run in this function, can take a long time and can result in the admin list page to render slowly. This cache should be made to persistent.

Make cache in wp_count_posts & wp_count_attachments persistent, by changing cache groups to post-queries and use the new wp_cache_get_salted and wp_cache_set_salted functions for cache invalidation.

Trac ticket: https://core.trac.wordpress.org/ticket/63945

[spacedmonkey]

Love feedback from @dd32, as this is platform level.

[dd32]

See also: #35430 and ticket:47884#comment:8 - I note this seems to be using the route proposed there to allow caching.

I don't have any other feedback, other than that I dislike the query this generates so I'm all for adding caching :D

[umarraza9450]

@spacedmonkey Thanks for highlighting this issue.
I’m also experiencing similar slow rendering on large sites due to the non-persistent counts cache.
You can see an example of this behavior on ​https://nextreport.id

where the admin list page occasionally loads much slower than expected when the SQL query runs.

It would be great if this cache could be made persistent to avoid repeated heavy queries between page requests.