WP_Site_Query::get_sites(): WP_Site[]|int[]|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

WP_Site[]|int[]|int

List of WP_Site objects, a list of site IDs when 'fields' is set to 'ids', or the number of sites when 'count' is passed as a query var.

Performance profile

How much work a call to WP_Site_Query::get_sites() 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

Only touches the object cache, via wp_cache_get_last_changed().

Scaling

Scales with input

The body loops, so the work grows with how much data it finds.

Instructions

41–161

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 187.

Plugin surface

3 hooks

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

Called by

1

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

What it touches

• hookthird-party callbacksdo_action_ref_array()called directly
• cacheobject cachewp_cache_get_last_changed()called directly
• serializeserialisationserialize()called directly

What one call costs · 86 distinct outcomes

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

Hooks and filters fired · 3

3 hooks fire while WP_Site_Query::get_sites() runs, in this order:

1. 1
   do_action( pre_get_sites )actionline 301 (+16 into the body)

   Fires before sites are retrieved.

2. 2
   apply_filters( sites_pre_query )filterline 341 (+56 into the body)

   Filters the site data before the get_sites query takes place.

3. 3
   apply_filters( the_sites )filterline 423 (+138 into the body)

   Filters the site query results.

Uses · 13

• do_action_ref_array()Calls the callback functions that have been added to an action hook, specifying arguments in an array.
• apply_filters_ref_array()Calls the callback functions that have been added to a filter hook, specifying arguments in an array.
• wp_array_slice_assoc()Extracts a slice of an array, given a list of keys.
• wp_cache_get_last_changed()Gets last changed date for the specified cache group.
• wp_cache_get_salted()Retrieves cached data if valid and unchanged.
• wp_cache_set_salted()Stores salted data in the cache.
• wp_lazyload_site_meta()Queue site meta for lazy-loading.
• _prime_site_caches()Adds any sites from the given IDs to the cache that do not already exist in cache.
• get_site()Retrieves site data given a site ID or site object.
• WP_Site_Query::parse_query()Parses arguments passed to the site query with default query parameters.
• WP_Meta_Query::__construct()Constructor.
• WP_Site_Query::get_site_ids()Used internally to get a list of site IDs matching the query vars.

Used by · 1

• WP_Site_Query::query()Sets up the WordPress query for retrieving sites.

Source code

View on Trac ↗View on GitHub ↗

285	public function get_sites() {286		global $wpdb;287 288		$this->parse_query();289 290		// Parse meta query.291		$this->meta_query = new WP_Meta_Query();292		$this->meta_query->parse_query_vars( $this->query_vars );293 294		/**295		 * Fires before sites are retrieved.296		 *297		 * @since 4.6.0298		 *299		 * @param WP_Site_Query $query Current instance of WP_Site_Query (passed by reference).300		 */301		do_action_ref_array( 'pre_get_sites', array( &$this ) );302 303		// Reparse query vars, in case they were modified in a 'pre_get_sites' callback.304		$this->meta_query->parse_query_vars( $this->query_vars );305		if ( ! empty( $this->meta_query->queries ) ) {306			$this->meta_query_clauses = $this->meta_query->get_sql( 'blog', $wpdb->blogs, 'blog_id', $this );307		}308 309		$site_data = null;310 311		/**312		 * Filters the site data before the get_sites query takes place.313		 *314		 * Return a non-null value to bypass WordPress' default site queries.315		 *316		 * The expected return type from this filter depends on the value passed317		 * in the request query vars:318		 * - When `$this->query_vars['count']` is set, the filter should return319		 *   the site count as an integer.320		 * - When `'ids' === $this->query_vars['fields']`, the filter should return321		 *   an array of site IDs.322		 * - Otherwise the filter should return an array of WP_Site objects.323		 *324		 * Note that if the filter returns an array of site data, it will be assigned325		 * to the `sites` property of the current WP_Site_Query instance.326		 *327		 * Filtering functions that require pagination information are encouraged to set328		 * the `found_sites` and `max_num_pages` properties of the WP_Site_Query object,329		 * passed to the filter by reference. If WP_Site_Query does not perform a database330		 * query, it will not have enough information to generate these values itself.331		 *332		 * @since 5.2.0333		 * @since 5.6.0 The returned array of site data is assigned to the `sites` property334		 *              of the current WP_Site_Query instance.335		 *336		 * @param WP_Site[]|int[]|int|null $site_data Return an array of site data to short-circuit WP's site query,337		 *                                            the site count as an integer if `$this->query_vars['count']` is set,338		 *                                            or null to run the normal queries.339		 * @param WP_Site_Query            $query     The WP_Site_Query instance, passed by reference.340		 */341		$site_data = apply_filters_ref_array( 'sites_pre_query', array( $site_data, &$this ) );342 343		if ( null !== $site_data ) {344			if ( is_array( $site_data ) && ! $this->query_vars['count'] ) {345				$this->sites = $site_data;346			}347 348			return $site_data;349		}350 351		// $args can include anything. Only use the args defined in the query_var_defaults to compute the key.352		$_args = wp_array_slice_assoc( $this->query_vars, array_keys( $this->query_var_defaults ) );353 354		// Ignore the $fields, $update_site_cache, $update_site_meta_cache argument as the queried result will be the same regardless.355		unset( $_args['fields'], $_args['update_site_cache'], $_args['update_site_meta_cache'] );356 357		$key          = md5( serialize( $_args ) );358		$last_changed = wp_cache_get_last_changed( 'sites' );359 360		$cache_key   = "get_sites:$key";361		$cache_value = wp_cache_get_salted( $cache_key, 'site-queries', $last_changed );362 363		if ( false === $cache_value ) {364			$site_ids = $this->get_site_ids();

Changelog

Introduced in 4.6.0. 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 6.9.7 tag, from src/wp-includes/class-wp-site-query.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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