maybe_redirect_404()
- Since
- MU (3.0.0)
- Source
wp-includes/ms-functions.php:2189
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.
Performance profile
How much work a call to maybe_redirect_404() 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
- 4–26
- 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, depending on the branch taken. The body compiles to 26.
Third-party callbacks on 'blog_redirect_404' 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
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 · 5 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost maybe_redirect_404() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
!is_main_site() | 4 | is_main_site() |
is_main_site() | 7–9 | is_main_site(), is_404() |
is_main_site() && is_404() && defined('NOBLOGREDIRECT') | 16 | is_main_site(), is_404(), apply_filters() |
is_main_site() && is_404() && defined('NOBLOGREDIRECT') && $destination !== "%siteurl%" | 23 | is_main_site(), is_404(), apply_filters(), wp_redirect(), exit() |
is_main_site() && is_404() && defined('NOBLOGREDIRECT') && $destination === "%siteurl%" | 26 | is_main_site(), is_404(), apply_filters(), network_home_url(), wp_redirect(), exit() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 26 | 4–26 | 5 | |
| 8.5 | 26 | 4–26 | 5 | |
| 8.4 | 26 | 4–26 | 5 | 1 more instruction than PHP 8.3 |
| 8.3 | 25 | 4–24 | 5 | |
| 8.2 | 25 | 4–24 | 5 | |
| 8.1 | 25 | 4–24 | 5 | |
| 7.4 | 25 | 4–24 | 5 |
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 maybe_redirect_404() runs, in this order:
- apply_filters( blog_redirect_404 )filterline 2200 (+11 into the body)
Filters the redirect URL for 404s on the main site.
Uses · 5
- is_main_site()Determines whether a site is the main site of the current network.
- is_404()Determines whether the query has resulted in a 404 (returns no results).
- apply_filters()Calls the callback functions that have been added to a filter hook.
- network_home_url()Retrieves the home URL for the current network.
- wp_redirect()Redirects to another page.
Source code
function maybe_redirect_404() { if ( is_main_site() && is_404() && defined( 'NOBLOGREDIRECT' ) ) { /** * Filters the redirect URL for 404s on the main site. * * The filter is only evaluated if the NOBLOGREDIRECT constant is defined. * * @since 3.0.0 * * @param string $no_blog_redirect The redirect URL defined in NOBLOGREDIRECT. */ $destination = apply_filters( 'blog_redirect_404', NOBLOGREDIRECT ); if ( $destination ) { if ( '%siteurl%' === $destination ) { $destination = network_home_url(); } wp_redirect( $destination ); exit; } }}Changelog
Introduced in MU (3.0.0). 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 7.0.4 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. - Corrections
- Something wrong on this page? Report it and it gets fixed in the next regeneration.