wp_admin_headers()
- Since
- 4.9.0, 6.8.0
- Source
wp-includes/functions.php:7205
Compatibility
- WordPress
- since 6.8.0
- 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.
Performance profile
How much work a call to wp_admin_headers() 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
- Constant
- Instructions
- 11
- Plugin surface
- 1 hook
- Called by
- 0
Touches nothing outside its own arguments.
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5. The body compiles to 11.
Third-party callbacks on 'admin_referrer_policy' run inside this call, and their cost is not bounded by anything here.
Nothing in core calls this; the cost is only what you spend yourself.
What it touches
- hookthird-party callbacks
apply_filters()called directly
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_admin_headers() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 11 | apply_filters(), header() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 11 | 11 | 0 | |
| 8.5 | 11 | 11 | 0 | |
| 8.4 | 11 | 11 | 0 | 3 fewer instructions than PHP 8.3 |
| 8.3 | 14 | 14 | 0 | |
| 8.2 | 14 | 14 | 0 | |
| 8.1 | 14 | 14 | 0 | |
| 7.4 | 14 | 14 | 0 |
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.
Hooks and filters fired · 1
One hook fires while wp_admin_headers() runs, in this order:
- apply_filters( admin_referrer_policy )filterline 7218 (+13 into the body)
Filters the admin referrer policy header value.
Uses · 1
- apply_filters()Calls the callback functions that have been added to a filter hook.
Source code
function wp_admin_headers() { $policy = 'strict-origin-when-cross-origin'; /** * Filters the admin referrer policy header value. * * @since 4.9.0 * @since 4.9.5 The default value was changed to 'strict-origin-when-cross-origin'. * * @link https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Referrer-Policy * * @param string $policy The admin referrer policy header value. Default 'strict-origin-when-cross-origin'. */ $policy = apply_filters( 'admin_referrer_policy', $policy ); header( sprintf( 'Referrer-Policy: %s', $policy ) );}Changelog
Introduced in 4.9.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
wp-admin/includes/misc.php to wp-includes/functions.php.from the docblockAbout this page
- Parsed data
- Generated from the wordpress-develop 7.0.4 tag, from
src/wp-includes/functions.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.