wppaste
WordPress

rsd_link()

Since
2.0.0
Source
wp-includes/general-template.php:3401
Displays the link to the Really Simple Discovery service endpoint.

Compatibility

WordPress
since 2.0.0
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.

Performance profile

How much work a call to rsd_link() 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

Touches nothing outside its own arguments.

Scaling
Constant

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

Instructions
12

Executed per call on PHP 8.5. The body compiles to 12.

Plugin surface
None

Nothing here hands control to plugin code.

Called by
0

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

What it touches

  • hookthird-party callbacksapply_filters()one call below rsd_link()

Further down the call graph this can also reach option, 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 rsd_link() can have, taken from its control-flow graph on PHP 8.5.

WhenInstructionsCalls it makes
always12site_url(), esc_url(), printf()

Across PHP versions

Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 12 instructions, 12 executed per call, 0 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.

Uses · 2

  • esc_url()Checks and cleans a URL.
  • site_url()Retrieves the URL for the current site where WordPress application files (e.g. wp-blog-header.php or the wp-admin/ folder) are accessible.

Source code

View on Trac View on GitHub 

function rsd_link() {	printf(		'<link rel="EditURI" type="application/rsd+xml" title="RSD" href="%s" />' . "\n",		esc_url( site_url( 'xmlrpc.php?rsd', 'rpc' ) )	);}

Changelog

Introduced in 2.0.0. Unchanged from 6.7.7 through 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.

About this page

Parsed data
Generated from the wordpress-develop 6.7.7 tag, from src/wp-includes/general-template.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.