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WordPress

check_upload_mimes( array $mimes ): array

Since
MU (3.0.0)
Source
wp-includes/ms-functions.php:2047
Checks an array of MIME types against a list of allowed types.

Description

WordPress ships with a set of allowed upload filetypes, which is defined in wp-includes/functions.php in get_allowed_mime_types(). This function is used to filter that list against the filetypes allowed provided by Multisite Super Admins at wp-admin/network/settings.php.

Compatibility

WordPress
since MU (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

$mimesarray

Return value

array

Performance profile

How much work a call to check_upload_mimes() 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

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

Scaling
Scales with input

The body loops, so the work grows with what you pass in.

Instructions
14–15

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 27.

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

  • optionnetwork optionget_site_option()called directly

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

WhenInstructionsCalls it makes
always14–15get_site_option(), explode()

Across PHP versions

PHPCompiledExecutedBranchesNotes
8.6-dev2714–156
8.52714–156
8.42714–1563 fewer instructions than PHP 8.3
8.33014–156
8.23014–156
8.13014–156
7.43014–156

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

  • get_site_option()Retrieve an option value for the current network based on name of option.
  • str_contains()Polyfill for `str_contains()` function added in PHP 8.0.

Source code

View on Trac View on GitHub 

function check_upload_mimes( $mimes ) {	$site_exts  = explode( ' ', get_site_option( 'upload_filetypes', 'jpg jpeg png gif' ) );	$site_mimes = array();	foreach ( $site_exts as $ext ) {		foreach ( $mimes as $ext_pattern => $mime ) {			if ( '' !== $ext && str_contains( $ext_pattern, $ext ) ) {				$site_mimes[ $ext_pattern ] = $mime;			}		}	}	return $site_mimes;}

Changelog

Introduced in MU (3.0.0). 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 6.8.8 tag, from src/wp-includes/ms-functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
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