cache_users( int[] $user_ids )
- Since
- 3.0.0
- Source
wp-includes/pluggable.php:125
Compatibility
- WordPress
- since 3.0.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.
Parameters
$user_idsint[]- User ID numbers list
Performance profile
How much work a call to cache_users() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Heavy
- Scaling
- Scales with input
- Instructions
- 14–28
- Plugin surface
- None
- Called by
- 2
Reaches the database via ->get_results().
The body loops, so the work grows with what you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 33.
Nothing here hands control to plugin code.
2 places in core call this, so the cost is paid more often than your own code shows.
What it touches
- sqldatabase query
->get_results()called directly - hookthird-party callbacks
apply_filters()one call below cache_users() - cacheobject cache
wp_cache_get_multiple()one call below cache_users()
What one call costs · 2 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost cache_users() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
empty($clean) | 14 | update_meta_cache(), _get_non_cached_ids() |
!empty($clean) | 27–28 | update_meta_cache(), _get_non_cached_ids(), ->get_results() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 33 | 14–28 | 3 | |
| 8.5 | 33 | 14–28 | 3 | |
| 8.4 | 33 | 14–28 | 3 | 4 fewer instructions than PHP 8.3 |
| 8.3 | 37 | 14–32 | 3 | |
| 8.2 | 37 | 14–32 | 3 | |
| 8.1 | 37 | 14–32 | 3 | |
| 7.4 | 37 | 14–32 | 3 |
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Uses · 3
- update_meta_cache()Updates the metadata cache for the specified objects.
- _get_non_cached_ids()Retrieves IDs that are not already present in the cache.
- update_user_caches()Updates all user caches.
Used by · 2
- WP_User_Query::query()Executes the query, with the current variables.
- update_post_author_caches()Updates post author user caches for a list of post objects.
Source code
function cache_users( $user_ids ) { global $wpdb; update_meta_cache( 'user', $user_ids ); $clean = _get_non_cached_ids( $user_ids, 'users' ); if ( empty( $clean ) ) { return; } $list = implode( ',', $clean ); $users = $wpdb->get_results( "SELECT * FROM $wpdb->users WHERE ID IN ($list)" ); foreach ( $users as $user ) { update_user_caches( $user ); } }Changelog
Introduced in 3.0.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 6.7.7 tag, from
src/wp-includes/pluggable.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
- Something wrong on this page? Report it and it gets fixed in the next regeneration.