Ticket #35791: 35791-class.2.patch

src/wp-includes/class-wp-site-query.php

@@ +1 @@
+<?php
+/**
+ * Site API: WP_Site_Query class
+ *
+ * @package WordPress
+ * @subpackage Sites
+ * @since 4.6.0
+ */
+
+/**
+ * Core class used for querying sites.
+ *
+ * @since 4.6.0
+ *
+ * @see WP_Site_Query::__construct() for accepted arguments.
+ */
+class WP_Site_Query {
+
+        /**
+         * SQL for database query.
+         *
+         * @since 4.6.0
+         * @access public
+         * @var string
+         */
+        public $request;
+
+        /**
+         * SQL query clauses.
+         *
+         * @since 4.6.0
+         * @access protected
+         * @var array
+         */
+        protected $sql_clauses = array(
+                'select'  => '',
+                'from'    => '',
+                'where'   => array(),
+                'groupby' => '',
+                'orderby' => '',
+                'limits'  => '',
+        );
+
+        /**
+         * Date query container.
+         *
+         * @since 4.6.0
+         * @access public
+         * @var object WP_Date_Query
+         */
+        public $date_query = false;
+
+        /**
+         * Query vars set by the user.
+         *
+         * @since 4.6.0
+         * @access public
+         * @var array
+         */
+        public $query_vars;
+
+        /**
+         * Default values for query vars.
+         *
+         * @since 4.6.0
+         * @access public
+         * @var array
+         */
+        public $query_var_defaults;
+
+        /**
+         * List of sites located by the query.
+         *
+         * @since 4.6.0
+         * @access public
+         * @var array
+         */
+        public $sites;
+
+        /**
+         * The amount of found sites for the current query.
+         *
+         * @since 4.6.0
+         * @access public
+         * @var int
+         */
+        public $found_sites = 0;
+
+        /**
+         * The number of pages.
+         *
+         * @since 4.6.0
+         * @access public
+         * @var int
+         */
+        public $max_num_pages = 0;
+
+        /**
+         * Makes private/protected methods readable for backwards compatibility.
+         *
+         * @since 4.6.0
+         * @access public
+         *
+         * @param callable $name      Method to call.
+         * @param array    $arguments Arguments to pass when calling.
+         * @return mixed|false Return value of the callback, false otherwise.
+         */
+        public function __call( $name, $arguments ) {
+                if ( 'get_search_sql' === $name ) {
+                        return call_user_func_array( array( $this, $name ), $arguments );
+                }
+
+                return false;
+        }
+
+        /**
+         * Sets up the site query, based on the query vars passed.
+         *
+         * @since 4.6.0
+         * @access public
+         *
+         * @param string|array $query {
+         *     Optional. Array or query string of site query parameters. Default empty.
+         *
+         *     @type array        $site__in          Array of site IDs to include. Default empty.
+         *     @type array        $site__not_in      Array of site IDs to exclude. Default empty.
+         *     @type bool         $count             Whether to return a site count (true) or array of site objects.
+         *                                           Default false.
+         *     @type array        $date_query        Date query clauses to limit sites by. See WP_Date_Query.
+         *                                           Default null.
+         *     @type string       $fields            Site fields to return. Accepts 'ids' for site IDs only or empty
+         *                                           for all fields. Default empty.
+         *     @type int          $ID                Currently unused.
+         *     @type int          $number            Maximum number of sites to retrieve. Default null (no limit).
+         *     @type int          $offset            Number of sites to offset the query. Used to build LIMIT clause.
+         *                                           Default 0.
+         *     @type bool         $no_found_rows     Whether to disable the `SQL_CALC_FOUND_ROWS` query. Default true.
+         *     @type string|array $orderby           Site status or array of statuses. Accepts 'id', 'domain', 'path',
+         *                                           'network_id', 'last_updated', 'registered', 'domain_length',
+         *                                           'path_length', 'site__in' and 'network__in'. Also accepts false,
+         *                                           an empty array, or 'none' to disable `ORDER BY` clause.
+         *                                           Default 'id'.
+         *     @type string       $order             How to order retrieved sites. Accepts 'ASC', 'DESC'. Default 'ASC'.
+         *     @type string       $domain            Limit results to those affiliated with a given network ID.
+         *                                           Default current network ID.
+         *     @type array        $domain__in        Array of domains to include affiliated sites for. Default empty.
+         *     @type array        $domain__not_in    Array of domains to exclude affiliated sites for. Default empty.
+         *     @type string       $path              Limit results to those affiliated with a given network ID.
+         *                                           Default current network ID.
+         *     @type array        $path__in          Array of paths to include affiliated sites for. Default empty.
+         *     @type array        $path__not_in      Array of paths to exclude affiliated sites for. Default empty.
+         *     @type int          $network_id        Limit results to those affiliated with a given network ID.
+         *                                           Default current network ID.
+         *     @type array        $network__in       Array of network IDs to include affiliated sites for. Default empty.
+         *     @type array        $network__not_in   Array of network IDs to exclude affiliated sites for. Default empty.
+         *     @type string       $search            Search term(s) to retrieve matching sites for. Default empty.
+         *     @type bool         $update_site_cache Whether to prime the cache for found sites. Default false.
+         * }
+         */
+        public function __construct( $query = '' ) {
+                $this->query_var_defaults = array(
+                        'fields'            => '',
+                        'ID'                => '',
+                        'site__in'          => '',
+                        'site__not_in'      => '',
+                        'number'            => 100,
+                        'offset'            => '',
+                        'no_found_rows'     => true,
+                        'orderby'           => 'ids',
+                        'order'             => 'DESC',
+                        'network_id'        => 0,
+                        'network__in'       => '',
+                        'network__not_in'   => '',
+                        'domain'            => '',
+                        'domain__in'        => '',
+                        'domain__not_in'    => '',
+                        'path'              => '',
+                        'path__in'          => '',
+                        'path__not_in'      => '',
+                        'public'            => null,
+                        'archived'          => null,
+                        'mature'            => null,
+                        'spam'              => null,
+                        'deleted'           => null,
+                        'search'            => '',
+                        'count'             => false,
+                        'date_query'        => null, // See WP_Date_Query
+                        'update_site_cache' => true,
+                );
+
+                if ( ! empty( $query ) ) {
+                        $this->query( $query );
+                }
+        }
+
+        /**
+         * Parses arguments passed to the site query with default query parameters.
+         *
+         * @since 4.6.0
+         * @access public
+         *
+         * @see WP_Site_Query::__construct()
+         *
+         * @param string|array $query Array or string of WP_Site_Query arguments. See WP_Site_Query::__construct().
+         */
+        public function parse_query( $query = '' ) {
+                if ( empty( $query ) ) {
+                        $query = $this->query_vars;
+                }
+
+                $this->query_vars = wp_parse_args( $query, $this->query_var_defaults );
+
+                /**
+                 * Fires after the site query vars have been parsed.
+                 *
+                 * @since 4.6.0
+                 *
+                 * @param WP_Site_Query &$this The WP_Site_Query instance (passed by reference).
+                 */
+                do_action_ref_array( 'parse_site_query', array( &$this ) );
+        }
+
+        /**
+         * Sets up the WordPress query for retrieving sites.
+         *
+         * @since 4.6.0
+         * @access public
+         *
+         * @param string|array $query Array or URL query string of parameters.
+         * @return array|int List of sites, or number of sites when 'count' is passed as a query var.
+         */
+        public function query( $query ) {
+                $this->query_vars = wp_parse_args( $query );
+
+                return $this->get_sites();
+        }
+
+        /**
+         * Retrieves a list of sites matching the query vars.
+         *
+         * @since 4.6.0
+         * @access public
+         *
+         * @global wpdb $wpdb WordPress database abstraction object.
+         *
+         * @return int|array The list of sites.
+         */
+        public function get_sites() {
+                global $wpdb;
+
+                $this->parse_query();
+
+                /**
+                 * Fires before sites are retrieved.
+                 *
+                 * @since 4.6.0
+                 *
+                 * @param WP_Site_Query &$this Current instance of WP_Site_Query, passed by reference.
+                 */
+                do_action_ref_array( 'pre_get_sites', array( &$this ) );
+
+                // $args can include anything. Only use the args defined in the query_var_defaults to compute the key.
+                $key          = md5( serialize( wp_array_slice_assoc( $this->query_vars, array_keys( $this->query_var_defaults ) ) ) );
+                $last_changed = wp_cache_get( 'last_changed', 'sites' );
+                if ( ! $last_changed ) {
+                        $last_changed = microtime();
+                        wp_cache_set( 'last_changed', $last_changed, 'sites' );
+                }
+                $cache_key = "get_site_ids:$key:$last_changed";
+
+                $site_ids = wp_cache_get( $cache_key, 'sites' );
+                if ( false === $site_ids ) {
+                        $site_ids = $this->get_site_ids();
+                        wp_cache_add( $cache_key, $site_ids, 'sites' );
+                }
+
+                // If querying for a count only, there's nothing more to do.
+                if ( $this->query_vars['count'] ) {
+                        // $site_ids is actually a count in this case.
+                        return intval( $site_ids );
+                }
+
+                $site_ids = array_map( 'intval', $site_ids );
+
+                $this->site_count = count( $this->sites );
+
+                if ( $site_ids && $this->query_vars['number'] && ! $this->query_vars['no_found_rows'] ) {
+                        /**
+                         * Filters the query used to retrieve found site count.
+                         *
+                         * @since 4.6.0
+                         *
+                         * @param string $found_sites_query SQL query. Default 'SELECT FOUND_ROWS()'.
+                         * @param WP_Site_Query $site_query The `WP_Site_Query` instance.
+                         */
+                        $found_sites_query = apply_filters( 'found_sites_query', 'SELECT FOUND_ROWS()', $this );
+
+                        $this->found_sites   = (int) $wpdb->get_var( $found_sites_query );
+                        $this->max_num_pages = ceil( $this->found_sites / $this->query_vars['number'] );
+                }
+
+                if ( 'ids' == $this->query_vars['fields'] ) {
+                        $this->sites = $site_ids;
+
+                        return $this->sites;
+                }
+
+                // Prime site network caches.
+                if ( $this->query_vars['update_site_cache'] ) {
+                        _prime_site_caches( $site_ids );
+                }
+
+                // Fetch full site objects from the primed cache.
+                $_sites = array();
+                foreach ( $site_ids as $site_id ) {
+                        if ( $_site = get_site( $site_id ) ) {
+                                $_sites[] = $_site;
+                        }
+                }
+
+                /**
+                 * Filters the site query results.
+                 *
+                 * @since 4.6.0
+                 *
+                 * @param array         $results An array of sites.
+                 * @param WP_Site_Query &$this   Current instance of WP_Site_Query, passed by reference.
+                 */
+                $_sites = apply_filters_ref_array( 'the_sites', array( $_sites, &$this ) );
+
+                // Convert to WP_Site instances.
+                $this->sites = array_map( 'get_site', $_sites );
+
+                return $this->sites;
+        }
+
+        /**
+         * Used internally to get a list of site IDs matching the query vars.
+         *
+         * @since 4.6.0
+         * @access protected
+         *
+         * @global wpdb $wpdb WordPress database abstraction object.
+         */
+        protected function get_site_ids() {
+                global $wpdb;
+
+                $order = $this->parse_order( $this->query_vars['order'] );
+
+                // Disable ORDER BY with 'none', an empty array, or boolean false.
+                if ( in_array( $this->query_vars['orderby'], array( 'none', array(), false ), true ) ) {
+                        $orderby = '';
+                } elseif ( ! empty( $this->query_vars['orderby'] ) ) {
+                        $ordersby = is_array( $this->query_vars['orderby'] ) ?
+                                $this->query_vars['orderby'] :
+                                preg_split( '/[,\s]/', $this->query_vars['orderby'] );
+
+                        $orderby_array         = array();
+                        foreach ( $ordersby as $_key => $_value ) {
+                                if ( ! $_value ) {
+                                        continue;
+                                }
+
+                                if ( is_int( $_key ) ) {
+                                        $_orderby = $_value;
+                                        $_order   = $order;
+                                } else {
+                                        $_orderby = $_key;
+                                        $_order   = $_value;
+                                }
+
+                                $parsed = $this->parse_orderby( $_orderby );
+
+                                if ( ! $parsed ) {
+                                        continue;
+                                }
+
+                                if ( 'site__in' === $_orderby || 'network__in' === $_orderby ) {
+                                        $orderby_array[] = $parsed;
+                                        continue;
+                                }
+
+                                $orderby_array[] = $parsed . ' ' . $this->parse_order( $_order );
+                        }
+
+                        $orderby = implode( ', ', $orderby_array );
+                } else {
+                        $orderby = "blog_id $order";
+                }
+
+                $number = absint( $this->query_vars['number'] );
+                $offset = absint( $this->query_vars['offset'] );
+
+                if ( ! empty( $number ) ) {
+                        if ( $offset ) {
+                                $limits = 'LIMIT ' . $offset . ',' . $number;
+                        } else {
+                                $limits = 'LIMIT ' . $number;
+                        }
+                }
+
+                if ( $this->query_vars['count'] ) {
+                        $fields = 'COUNT(*)';
+                } else {
+                        $fields = "blog_id";
+                }
+
+                // Parse site IDs for an IN clause.
+                $site_id = absint( $this->query_vars['ID'] );
+                if ( ! empty( $site_id ) ) {
+                        $this->sql_clauses['where']['ID'] = $wpdb->prepare( 'blog_id = %d', $site_id );
+                }
+
+                // Parse site IDs for an IN clause.
+                if ( ! empty( $this->query_vars['site__in'] ) ) {
+                        $this->sql_clauses['where']['site__in'] = "blog_id IN ( " . implode( ',', wp_parse_id_list( $this->query_vars['site__in'] ) ) . ' )';
+                }
+
+                // Parse site IDs for a NOT IN clause.
+                if ( ! empty( $this->query_vars['site__not_in'] ) ) {
+                        $this->sql_clauses['where']['site__not_in'] = "blog_id NOT IN ( " . implode( ',', wp_parse_id_list( $this->query_vars['site__not_in'] ) ) . ' )';
+                }
+
+                $network_id = absint( $this->query_vars['network_id'] );
+
+                if ( ! empty( $network_id ) ) {
+                        $this->sql_clauses['where']['network_id'] = $wpdb->prepare( 'site_id = %d', $network_id );
+                }
+
+                // Parse site network IDs for an IN clause.
+                if ( ! empty( $this->query_vars['network__in'] ) ) {
+                        $this->sql_clauses['where']['network__in'] = 'site_id IN ( ' . implode( ',', wp_parse_id_list( $this->query_vars['network__in'] ) ) . ' )';
+                }
+
+                // Parse site network IDs for a NOT IN clause.
+                if ( ! empty( $this->query_vars['network__not_in'] ) ) {
+                        $this->sql_clauses['where']['network__not_in'] = 'site_id NOT IN ( ' . implode( ',', wp_parse_id_list( $this->query_vars['network__not_in'] ) ) . ' )';
+                }
+
+                if ( ! empty( $this->query_vars['domain'] ) ) {
+                        $this->sql_clauses['where']['domain'] = $wpdb->prepare( 'domain = %s', $this->query_vars['domain'] );
+                }
+
+                // Parse site domain for an IN clause.
+                if ( is_array( $this->query_vars['domain__in'] ) ) {
+                        $this->sql_clauses['where']['domain__in'] = "domain IN ( '" . implode( "', '", $wpdb->_escape( $this->query_vars['domain__in'] ) ) . "' )";
+                }
+
+                // Parse site domain for a NOT IN clause.
+                if ( is_array( $this->query_vars['domain__not_in'] ) ) {
+                        $this->sql_clauses['where']['domain__not_in'] = "domain NOT IN ( '" . implode( "', '", $wpdb->_escape( $this->query_vars['domain__not_in'] ) ) . "' )";
+                }
+
+                if ( ! empty( $this->query_vars['path'] ) ) {
+                        $this->sql_clauses['where']['path'] = $wpdb->prepare( 'path = %s', $this->query_vars['path'] );
+                }
+
+                // Parse site path for an IN clause.
+                if ( is_array( $this->query_vars['path__in'] ) ) {
+                        $this->sql_clauses['where']['path__in'] = "path IN ( '" . implode( "', '", $wpdb->_escape( $this->query_vars['path__in'] ) ) . "' )";
+                }
+
+                // Parse site path for a NOT IN clause.
+                if ( is_array( $this->query_vars['path__not_in'] ) ) {
+                        $this->sql_clauses['where']['path__not_in'] = "path NOT IN ( '" . implode( "', '", $wpdb->_escape( $this->query_vars['path__not_in'] ) ) . "' )";
+                }
+
+                if ( is_numeric( $this->query_vars['archived'] ) ) {
+                        $archived                               = absint( $this->query_vars['archived'] );
+                        $this->sql_clauses['where']['archived'] = $wpdb->prepare( "archived = %d ", $archived );
+                }
+
+                if ( is_numeric( $this->query_vars['mature'] ) ) {
+                        $mature                               = absint( $this->query_vars['mature'] );
+                        $this->sql_clauses['where']['mature'] = $wpdb->prepare( "mature = %d ", $mature );
+                }
+
+                if ( is_numeric( $this->query_vars['spam'] ) ) {
+                        $spam                               = absint( $this->query_vars['spam'] );
+                        $this->sql_clauses['where']['spam'] = $wpdb->prepare( "spam = %d ", $spam );
+                }
+
+                if ( is_numeric( $this->query_vars['deleted'] ) ) {
+                        $deleted                               = absint( $this->query_vars['deleted'] );
+                        $this->sql_clauses['where']['deleted'] = $wpdb->prepare( "deleted = %d ", $deleted );
+                }
+
+                if ( is_numeric( $this->query_vars['public'] ) ) {
+                        $public                               = absint( $this->query_vars['public'] );
+                        $this->sql_clauses['where']['public'] = $wpdb->prepare( "public = %d ", $public );
+                }
+
+                // Falsey search strings are ignored.
+                if ( strlen( $this->query_vars['search'] ) ) {
+                        $this->sql_clauses['where']['search'] = $this->get_search_sql(
+                                $this->query_vars['search'],
+                                array( 'domain', 'path' )
+                        );
+                }
+
+                $date_query = $this->query_vars['date_query'];
+                if ( ! empty( $date_query ) && is_array( $date_query ) ) {
+                        $this->date_query                         = new WP_Date_Query( $date_query, 'registered' );
+                        $this->sql_clauses['where']['date_query'] = preg_replace( '/^\s*AND\s*/', '', $this->date_query->get_sql() );
+                }
+
+                $where = implode( ' AND ', $this->sql_clauses['where'] );
+
+                $pieces = array( 'fields', 'join', 'where', 'orderby', 'limits', 'groupby' );
+
+                /**
+                 * Filters the site query clauses.
+                 *
+                 * @since 4.6.0
+                 *
+                 * @param array $pieces A compacted array of site query clauses.
+                 * @param WP_Site_Query &$this Current instance of WP_Site_Query, passed by reference.
+                 */
+                $clauses = apply_filters_ref_array( 'sites_clauses', array( compact( $pieces ), &$this ) );
+
+                $fields  = isset( $clauses['fields'] ) ? $clauses['fields'] : '';
+                $join    = isset( $clauses['join'] ) ? $clauses['join'] : '';
+                $where   = isset( $clauses['where'] ) ? $clauses['where'] : '';
+                $orderby = isset( $clauses['orderby'] ) ? $clauses['orderby'] : '';
+                $limits  = isset( $clauses['limits'] ) ? $clauses['limits'] : '';
+                $groupby = isset( $clauses['groupby'] ) ? $clauses['groupby'] : '';
+
+                if ( $where ) {
+                        $where = 'WHERE ' . $where;
+                }
+
+                if ( $groupby ) {
+                        $groupby = 'GROUP BY ' . $groupby;
+                }
+
+                if ( $orderby ) {
+                        $orderby = "ORDER BY $orderby";
+                }
+
+                $found_rows = '';
+                if ( ! $this->query_vars['no_found_rows'] ) {
+                        $found_rows = 'SQL_CALC_FOUND_ROWS';
+                }
+
+                $this->sql_clauses['select']  = "SELECT $found_rows $fields";
+                $this->sql_clauses['from']    = "FROM $wpdb->blogs $join";
+                $this->sql_clauses['groupby'] = $groupby;
+                $this->sql_clauses['orderby'] = $orderby;
+                $this->sql_clauses['limits']  = $limits;
+
+                $this->request = "{$this->sql_clauses['select']} {$this->sql_clauses['from']} {$where} {$this->sql_clauses['groupby']} {$this->sql_clauses['orderby']} {$this->sql_clauses['limits']}";
+
+                if ( $this->query_vars['count'] ) {
+                        return intval( $wpdb->get_var( $this->request ) );
+                }
+
+                $site_ids = $wpdb->get_col( $this->request );
+
+                return array_map( 'intval', $site_ids );
+        }
+
+        /**
+         * Used internally to generate an SQL string for searching across multiple columns
+         *
+         * @since 4.6.0
+         * @access protected
+         *
+         * @global wpdb  $wpdb WordPress database abstraction object.
+         *
+         * @param string $string  Search string.
+         * @param array  $columns Columns to search.
+         * @return string Search SQL.
+         */
+        protected function get_search_sql( $string, $columns ) {
+                global $wpdb;
+
+                $like = '%' . $wpdb->esc_like( $string ) . '%';
+
+                $searches = array();
+                foreach ( $columns as $column ) {
+                        $searches[] = $wpdb->prepare( "$column LIKE %s", $like );
+                }
+
+                return '(' . implode( ' OR ', $searches ) . ')';
+        }
+
+        /**
+         * Parses and sanitizes 'orderby' keys passed to the site query.
+         *
+         * @since 4.6.0
+         * @access protected
+         *
+         * @global wpdb $wpdb WordPress database abstraction object.
+         *
+         * @param string $orderby Alias for the field to order by.
+         * @return string|false Value to used in the ORDER clause. False otherwise.
+         */
+        protected function parse_orderby( $orderby ) {
+                global $wpdb;
+
+                $parsed = false;
+
+                switch ( $orderby ) {
+                        case 'site__in':
+                                $site__in = implode( ',', array_map( 'absint', $this->query_vars['site__in'] ) );
+                                $parsed = "FIELD( {$wpdb->blogs}.blog_id, $site__in )";
+                                break;
+                        case 'network__in':
+                                $network__in = implode( ',', array_map( 'absint', $this->query_vars['network__in'] ) );
+                                $parsed = "FIELD( {$wpdb->blogs}.site_id, $network__in )";
+                                break;
+                        case 'domain':
+                        case 'last_updated':
+                        case 'path':
+                        case 'registered':
+                                $parsed = $orderby;
+                                break;
+                        case 'network_id':
+                                $parsed = "site_id";
+                                break;
+                        case 'domain_length':
+                                $parsed = "CHAR_LENGTH(domain)";
+                                break;
+                        case 'path_length':
+                                $parsed = "CHAR_LENGTH(path)";
+                                break;
+                        case 'id':
+                                $parsed = "blog_id";
+                                break;
+                }
+
+                return $parsed;
+        }
+
+        /**
+         * Parses an 'order' query variable and cast it to 'ASC' or 'DESC' as necessary.
+         *
+         * @since 4.6.0
+         * @access protected
+         *
+         * @param string $order The 'order' query variable.
+         * @return string The sanitized 'order' query variable.
+         */
+        protected function parse_order( $order ) {
+                if ( ! is_string( $order ) || empty( $order ) ) {
+                        return 'ASC';
+                }
+
+                if ( 'ASC' === strtoupper( $order ) ) {
+                        return 'ASC';
+                } else {
+                        return 'DESC';
+                }
+        }
+}

src/wp-includes/date.php

@@ -491 +491 @@
                 $valid_columns = array(
                         'post_date', 'post_date_gmt', 'post_modified',
                         'post_modified_gmt', 'comment_date', 'comment_date_gmt',
-                        'user_registered',
+                        'user_registered', 'registered', 'last_updated',
                 );
 
                 // Attempt to detect a table prefix.
@@ -525 +525 @@
                                 $wpdb->users => array(
                                         'user_registered',
                                 ),
+                                $wpdb->blogs => array(
+                                        'registered',
+                                        'last_updated',
+                                ),
                         );
 
                         // If it's a known column name, add the appropriate table prefix.

src/wp-includes/ms-blogs.php

@@ -468 +468 @@
 }
 
 /**
+ * Retrieves site data given a site ID or site object.
+ *
+ * If an object is passed then the site data will be cached and then returned
+ * after being passed through a filter. If the site is empty, then the global
+ * site variable will be used, if it is set.
+ *
+ * @since 4.6.0
+ *
+ * @global WP_Site $site
+ *
+ * @param WP_Site|string|int $site Site to retrieve.
+ * @param string $output Optional. OBJECT or ARRAY_A or ARRAY_N constants.
+ * @return WP_Site|array|null Depends on $output value.
+ */
+function get_site( &$site = null, $output = OBJECT ) {
+        global $current_blog;
+        if ( empty( $site ) && isset( $current_blog ) ) {
+                $site = $current_blog;
+        }
+
+        if ( $site instanceof WP_Site ) {
+                $_site = $site;
+        } elseif ( is_object( $site ) ) {
+                $_site = new WP_Site( $site );
+        } else {
+                $_site = WP_Site::get_instance( $site );
+        }
+
+        if ( ! $_site ) {
+                return null;
+        }
+
+        /**
+         * Fires after a site is retrieved.
+         *
+         * @since 4.6.0
+         *
+         * @param mixed $_site Site data.
+         */
+        $_site = apply_filters( 'get_site', $_site );
+
+        if ( $output == OBJECT ) {
+                return $_site;
+        } elseif ( $output == ARRAY_A ) {
+                return $_site->to_array();
+        } elseif ( $output == ARRAY_N ) {
+                return array_values( $_site->to_array() );
+        }
+
+        return $_site;
+}
+
+/**
+ * Adds any sites from the given ids to the cache that do not already exist in cache
+ *
+ * @since 4.6.0
+ * @access private
+ *
+ * @see update_site_cache()
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param array $ids ID list.
+ */
+function _prime_site_caches( $ids ) {
+        global $wpdb;
+
+        $non_cached_ids = _get_non_cached_ids( $ids, 'sites' );
+        if ( ! empty( $non_cached_ids ) ) {
+                $fresh_sites = $wpdb->get_results( sprintf( "SELECT * FROM $wpdb->blogs WHERE blog_id IN (%s)", join( ",", $non_cached_ids ) ) );
+
+                update_site_cache( $fresh_sites );
+        }
+}
+
+/**
+ * Updates sites in cache.
+ *
+ * @since 4.6.0
+ *
+ * @param array $sites Array of site objects, passed by reference.
+ */
+function update_site_cache( &$sites ) {
+        if ( ! $sites ) {
+                return;
+        }
+
+        foreach ( $sites as $site ) {
+                wp_cache_add( $site->blog_id, $site, 'sites' );
+                wp_cache_add( $site->blog_id . 'short', $site, 'blog-details' );
+        }
+}
+
+/**
  * Retrieve option value for a given blog id based on name of option.
  *
  * If the option does not exist or does not have a value, then the return value

src/wp-settings.php

@@ -99 +99 @@
 
 // Initialize multisite if enabled.
 if ( is_multisite() ) {
+        require( ABSPATH . WPINC . '/class-wp-site-query.php' );
         require( ABSPATH . WPINC . '/ms-blogs.php' );
         require( ABSPATH . WPINC . '/ms-settings.php' );
 } elseif ( ! defined( 'MULTISITE' ) ) {