get_main_network_id(): int

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Return value

int

The ID of the main network.

Performance profile

How much work a call to get_main_network_id() 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

4–28

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 33.

Plugin surface

1 hook

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

Called by

7

7 places in core call this, so the cost is paid more often than your own code shows.

What it touches

• hookthird-party callbacksapply_filters()called directly

What one call costs · 3 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost get_main_network_id() can have, taken from its control-flow graph on PHP 8.5.

Hooks and filters fired · 1

One hook fires while get_main_network_id() runs, in this order:

1. 1
   apply_filters( get_main_network_id )filterline 6633 (+29 into the body)

   Filters the main network ID.

Uses · 4

• is_multisite()Determines whether Multisite is enabled.
• get_network()Retrieves network data given a network ID or network object.
• get_networks()Retrieves a list of networks.
• apply_filters()Calls the callback functions that have been added to a filter hook.

Used by · 7

• WP_Application_Passwords::create_new_application_password()Creates a new application password.
• WP_Application_Passwords::is_in_use()Checks if application passwords are being used by the site.
• get_current_network_id()Retrieves the current network ID.
• is_main_network()Determines whether a network is the main network of the Multisite installation.
• is_site_meta_supported()Determines whether site meta is enabled.
• upgrade_560()Executes changes made in WordPress 5.6.0.
• upgrade_network()Executes network-level upgrade routines.

Source code

View on Trac ↗View on GitHub ↗

6604function get_main_network_id() {6605	if ( ! is_multisite() ) {6606		return 1;6607	}6608 6609	$current_network = get_network();6610 6611	if ( defined( 'PRIMARY_NETWORK_ID' ) ) {6612		$main_network_id = PRIMARY_NETWORK_ID;6613	} elseif ( isset( $current_network->id ) && 1 === (int) $current_network->id ) {6614		// If the current network has an ID of 1, assume it is the main network.6615		$main_network_id = 1;6616	} else {6617		$_networks       = get_networks(6618			array(6619				'fields' => 'ids',6620				'number' => 1,6621			)6622		);6623		$main_network_id = array_shift( $_networks );6624	}6625 6626	/**6627	 * Filters the main network ID.6628	 *6629	 * @since 4.3.06630	 *6631	 * @param int $main_network_id The ID of the main network.6632	 */6633	return (int) apply_filters( 'get_main_network_id', $main_network_id );6634}

Changelog

Introduced in 4.3.0. 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

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