WP_Dependencies::get_etag( string[] $load ): string
- Since
- 6.7.0
- Source
wp-includes/class-wp-dependencies.php:533
Compatibility
- WordPress
- since 6.7.0
- 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
$loadstring[]- Array of script or style handles to load.
Return value
string- Etag header.
Performance profile
How much work a call to WP_Dependencies::get_etag() 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
- Trivial
- Scaling
- Scales with input
- Instructions
- 13–14
- Plugin surface
- None
- Called by
- 0
Touches nothing outside its own arguments.
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 29.
Nothing here hands control to plugin code.
Nothing in core calls this; the cost is only what you spend yourself.
What one call costs · 1 distinct outcome
One number would be a lie: the work depends on which branch runs. These are every distinct cost WP_Dependencies::get_etag() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 13–14 | md5() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 29 instructions, 13–14 executed per call, 4 branches. The work does not change between versions.
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.
Source code
public function get_etag( $load ) { /* * Note: wp_get_wp_version() is not used here, as this file can be included * via wp-admin/load-scripts.php or wp-admin/load-styles.php, in which case * wp-includes/functions.php is not loaded. */ global $wp_version; $etag = "WP:{$wp_version};"; foreach ( $load as $handle ) { if ( ! array_key_exists( $handle, $this->registered ) ) { continue; } $ver = $this->registered[ $handle ]->ver ?? $wp_version; $etag .= "{$handle}:{$ver};"; } /* * This is not intended to be cryptographically secure, just a fast way to get * a fixed length string based on the script versions. As this file does not * load the full WordPress environment, it is not possible to use the salted * wp_hash() function. */ return 'W/"' . md5( $etag ) . '"'; }Changelog
Introduced in 6.7.0. 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 7.1.0 tag, from
src/wp-includes/class-wp-dependencies.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.