wppaste
WordPress

do_favicon()

Since
5.4.0
Source
wp-includes/functions.php:1741
Displays the favicon.ico file content.

Compatibility

WordPress
since 5.4.0
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 do_favicon() 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
Moderate

Reads stored settings via get_option(), cached per request but not free on a cold cache.

Scaling
Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions
16

Executed per call on PHP 8.5. The body compiles to 16.

Plugin surface
1 hook

Third-party callbacks on 'do_faviconico' run inside this call, and their cost is not bounded by anything here.

Called by
0

Nothing in core calls this; the cost is only what you spend yourself.

What it touches

  • hookthird-party callbacksdo_action()called directly
  • optionoption read or writeget_option()one call below do_favicon()

Further down the call graph this can also reach cache, serialize, query and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

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 do_favicon() can have, taken from its control-flow graph on PHP 8.5.

WhenInstructionsCalls it makes
always16do_action(), includes_url(), get_site_icon_url(), wp_redirect(), exit()

Across PHP versions

PHPCompiledExecutedBranchesNotes
8.6-dev16160
8.516160
8.4161602 more instructions than PHP 8.3
8.314140
8.214140
8.114140
7.414140

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 do_favicon() runs, in this order:

  1. do_action( do_faviconico )actionline 1747 (+6 into the body)

    Fires when serving the favicon.ico file.

Uses · 4

Source code

function do_favicon() {	/**	 * Fires when serving the favicon.ico file.	 *	 * @since 5.4.0	 */	do_action( 'do_faviconico' ); 	wp_redirect( get_site_icon_url( 32, includes_url( 'images/w-logo-blue-white-bg.png' ) ) );	exit;}

Changelog

Introduced in 5.4.0. One change between 6.7.7 and 7.1.0.

  1. 6.7.7
  2. 6.8.8
  3. 6.9.7
  4. 7.0.4
  5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

7.1.0
Return type changed from none to never.verified against source
5.4.0
Introduced.from the docblock

About this page

Parsed data
Generated from the wordpress-develop 6.8.8 tag, from src/wp-includes/functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
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