Index: src/wp-includes/ms-blogs.php
===================================================================
--- src/wp-includes/ms-blogs.php	(revision 40568)
+++ src/wp-includes/ms-blogs.php	(working copy)
@@ -8,6 +8,9 @@
  * @since MU
  */
 
+require_once( ABSPATH . WPINC . '/ms-site.php' );
+require_once( ABSPATH . WPINC . '/ms-network.php' );
+
 /**
  * Update the last_updated field for the current site.
  *
@@ -439,48 +442,6 @@
 }
 
 /**
- * Clean the blog cache
- *
- * @since 3.5.0
- *
- * @global bool $_wp_suspend_cache_invalidation
- *
- * @param WP_Site $blog The site object to be cleared from cache.
- */
-function clean_blog_cache( $blog ) {
-	global $_wp_suspend_cache_invalidation;
-
-	if ( ! empty( $_wp_suspend_cache_invalidation ) ) {
-		return;
-	}
-
-	$blog_id = $blog->blog_id;
-	$domain_path_key = md5( $blog->domain . $blog->path );
-
-	wp_cache_delete( $blog_id, 'sites' );
-	wp_cache_delete( $blog_id, 'site-details' );
-	wp_cache_delete( $blog_id, 'blog-details' );
-	wp_cache_delete( $blog_id . 'short' , 'blog-details' );
-	wp_cache_delete( $domain_path_key, 'blog-lookup' );
-	wp_cache_delete( $domain_path_key, 'blog-id-cache' );
-	wp_cache_delete( 'current_blog_' . $blog->domain, 'site-options' );
-	wp_cache_delete( 'current_blog_' . $blog->domain . $blog->path, 'site-options' );
-
-	/**
-	 * Fires immediately after a site has been removed from the object cache.
-	 *
-	 * @since 4.6.0
-	 *
-	 * @param int     $id              Blog ID.
-	 * @param WP_Site $blog            Site object.
-	 * @param string  $domain_path_key md5 hash of domain and path.
-	 */
-	do_action( 'clean_site_cache', $blog_id, $blog, $domain_path_key );
-
-	wp_cache_set( 'last_changed', microtime(), 'sites' );
-}
-
-/**
  * Cleans the site details cache for a site.
  *
  * @since 4.7.4
@@ -498,147 +459,6 @@
 }
 
 /**
- * Retrieves site data given a site ID or site object.
- *
- * Site data will be cached and returned after being passed through a filter.
- * If the provided site is empty, the current site global will be used.
- *
- * @since 4.6.0
- *
- * @param WP_Site|int|null $site Optional. Site to retrieve. Default is the current site.
- * @return WP_Site|null The site object or null if not found.
- */
-function get_site( $site = null ) {
-	if ( empty( $site ) ) {
-		$site = get_current_blog_id();
-	}
-
-	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 WP_Site $_site Site data.
-	 */
-	$_site = apply_filters( 'get_site', $_site );
-
-	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( ",", array_map( 'intval', $non_cached_ids ) ) ) );
-
-		update_site_cache( $fresh_sites );
-	}
-}
-
-/**
- * Updates sites in cache.
- *
- * @since 4.6.0
- *
- * @param array $sites Array of site objects.
- */
-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' );
-	}
-}
-
-/**
- * Retrieves a list of sites matching requested arguments.
- *
- * @since 4.6.0
- * @since 4.8.0 Introduced the 'lang_id', 'lang__in', and 'lang__not_in' parameters.
- *
- * @see WP_Site_Query::parse_query()
- *
- * @param string|array $args {
- *     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' (returns an array of site IDs)
- *                                           or empty (returns an array of complete site objects). Default empty.
- *     @type int          $ID                A site ID to only return that site. Default empty.
- *     @type int          $number            Maximum number of sites to retrieve. Default 100.
- *     @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 int          $network_id        Limit results to those affiliated with a given network ID. If 0,
- *                                           include all networks. Default 0.
- *     @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       $domain            Limit results to those affiliated with a given domain. Default empty.
- *     @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 path. Default empty.
- *     @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          $public            Limit results to public sites. Accepts '1' or '0'. Default empty.
- *     @type int          $archived          Limit results to archived sites. Accepts '1' or '0'. Default empty.
- *     @type int          $mature            Limit results to mature sites. Accepts '1' or '0'. Default empty.
- *     @type int          $spam              Limit results to spam sites. Accepts '1' or '0'. Default empty.
- *     @type int          $deleted           Limit results to deleted sites. Accepts '1' or '0'. Default empty.
- *     @type int          $lang_id           Limit results to a language ID. Default empty.
- *     @type array        $lang__in          Array of language IDs to include affiliated sites for. Default empty.
- *     @type array        $lang__not_in      Array of language IDs to exclude affiliated sites for. Default empty.
- *     @type string       $search            Search term(s) to retrieve matching sites for. Default empty.
- *     @type array        $search_columns    Array of column names to be searched. Accepts 'domain' and 'path'.
- *                                           Default empty array.
- *     @type bool         $update_site_cache Whether to prime the cache for found sites. Default false.
- * }
- * @return array List of sites.
- */
-function get_sites( $args = array() ) {
-	$query = new WP_Site_Query();
-
-	return $query->query( $args );
-}
-
-/**
  * 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
@@ -1095,135 +915,6 @@
 }
 
 /**
- * Retrieves a list of networks.
- *
- * @since 4.6.0
- *
- * @param string|array $args Optional. Array or string of arguments. See WP_Network_Query::parse_query()
- *                           for information on accepted arguments. Default empty array.
- * @return int|array List of networks or number of found networks if `$count` argument is true.
- */
-function get_networks( $args = array() ) {
-	$query = new WP_Network_Query();
-
-	return $query->query( $args );
-}
-
-/**
- * Retrieves network data given a network ID or network object.
- *
- * Network data will be cached and returned after being passed through a filter.
- * If the provided network is empty, the current network global will be used.
- *
- * @since 4.6.0
- *
- * @global WP_Network $current_site
- *
- * @param WP_Network|int|null $network Optional. Network to retrieve. Default is the current network.
- * @return WP_Network|null The network object or null if not found.
- */
-function get_network( $network = null ) {
-	global $current_site;
-	if ( empty( $network ) && isset( $current_site ) ) {
-		$network = $current_site;
-	}
-
-	if ( $network instanceof WP_Network ) {
-		$_network = $network;
-	} elseif ( is_object( $network ) ) {
-		$_network = new WP_Network( $network );
-	} else {
-		$_network = WP_Network::get_instance( $network );
-	}
-
-	if ( ! $_network ) {
-		return null;
-	}
-
-	/**
-	 * Fires after a network is retrieved.
-	 *
-	 * @since 4.6.0
-	 *
-	 * @param WP_Network $_network Network data.
-	 */
-	$_network = apply_filters( 'get_network', $_network );
-
-	return $_network;
-}
-
-/**
- * Removes a network from the object cache.
- *
- * @since 4.6.0
- *
- * @global bool $_wp_suspend_cache_invalidation
- *
- * @param int|array $ids Network ID or an array of network IDs to remove from cache.
- */
-function clean_network_cache( $ids ) {
-	global $_wp_suspend_cache_invalidation;
-
-	if ( ! empty( $_wp_suspend_cache_invalidation ) ) {
-		return;
-	}
-
-	foreach ( (array) $ids as $id ) {
-		wp_cache_delete( $id, 'networks' );
-
-		/**
-		 * Fires immediately after a network has been removed from the object cache.
-		 *
-		 * @since 4.6.0
-		 *
-		 * @param int $id Network ID.
-		 */
-		do_action( 'clean_network_cache', $id );
-	}
-
-	wp_cache_set( 'last_changed', microtime(), 'networks' );
-}
-
-/**
- * Updates the network cache of given networks.
- *
- * Will add the networks in $networks to the cache. If network ID already exists
- * in the network cache then it will not be updated. The network is added to the
- * cache using the network group with the key using the ID of the networks.
- *
- * @since 4.6.0
- *
- * @param array $networks Array of network row objects.
- */
-function update_network_cache( $networks ) {
-	foreach ( (array) $networks as $network ) {
-		wp_cache_add( $network->id, $network, 'networks' );
-	}
-}
-
-/**
- * Adds any networks from the given IDs to the cache that do not already exist in cache.
- *
- * @since 4.6.0
- * @access private
- *
- * @see update_network_cache()
- * @global wpdb $wpdb WordPress database abstraction object.
- *
- * @param array $network_ids Array of network IDs.
- */
-function _prime_network_caches( $network_ids ) {
-	global $wpdb;
-
-	$non_cached_ids = _get_non_cached_ids( $network_ids, 'networks' );
-	if ( !empty( $non_cached_ids ) ) {
-		$fresh_networks = $wpdb->get_results( sprintf( "SELECT $wpdb->site.* FROM $wpdb->site WHERE id IN (%s)", join( ",", array_map( 'intval', $non_cached_ids ) ) ) );
-
-		update_network_cache( $fresh_networks );
-	}
-}
-
-/**
  * Handler for updating the blog date when a post is published or an already published post is changed.
  *
  * @since 3.3.0
Index: src/wp-includes/ms-network.php
===================================================================
--- src/wp-includes/ms-network.php	(nonexistent)
+++ src/wp-includes/ms-network.php	(working copy)
@@ -0,0 +1,137 @@
+<?php
+/**
+ * Network API
+ *
+ * @package WordPress
+ * @subpackage Multisite
+ * @since 4.8.0
+ */
+
+/**
+ * Retrieves a list of networks.
+ *
+ * @since 4.6.0
+ *
+ * @param string|array $args Optional. Array or string of arguments. See WP_Network_Query::parse_query()
+ *                           for information on accepted arguments. Default empty array.
+ * @return int|array List of networks or number of found networks if `$count` argument is true.
+ */
+function get_networks( $args = array() ) {
+	$query = new WP_Network_Query();
+
+	return $query->query( $args );
+}
+
+/**
+ * Retrieves network data given a network ID or network object.
+ *
+ * Network data will be cached and returned after being passed through a filter.
+ * If the provided network is empty, the current network global will be used.
+ *
+ * @since 4.6.0
+ *
+ * @global WP_Network $current_site
+ *
+ * @param WP_Network|int|null $network Optional. Network to retrieve. Default is the current network.
+ * @return WP_Network|null The network object or null if not found.
+ */
+function get_network( $network = null ) {
+	global $current_site;
+	if ( empty( $network ) && isset( $current_site ) ) {
+		$network = $current_site;
+	}
+
+	if ( $network instanceof WP_Network ) {
+		$_network = $network;
+	} elseif ( is_object( $network ) ) {
+		$_network = new WP_Network( $network );
+	} else {
+		$_network = WP_Network::get_instance( $network );
+	}
+
+	if ( ! $_network ) {
+		return null;
+	}
+
+	/**
+	 * Fires after a network is retrieved.
+	 *
+	 * @since 4.6.0
+	 *
+	 * @param WP_Network $_network Network data.
+	 */
+	$_network = apply_filters( 'get_network', $_network );
+
+	return $_network;
+}
+
+/**
+ * Removes a network from the object cache.
+ *
+ * @since 4.6.0
+ *
+ * @global bool $_wp_suspend_cache_invalidation
+ *
+ * @param int|array $ids Network ID or an array of network IDs to remove from cache.
+ */
+function clean_network_cache( $ids ) {
+	global $_wp_suspend_cache_invalidation;
+
+	if ( ! empty( $_wp_suspend_cache_invalidation ) ) {
+		return;
+	}
+
+	foreach ( (array) $ids as $id ) {
+		wp_cache_delete( $id, 'networks' );
+
+		/**
+		 * Fires immediately after a network has been removed from the object cache.
+		 *
+		 * @since 4.6.0
+		 *
+		 * @param int $id Network ID.
+		 */
+		do_action( 'clean_network_cache', $id );
+	}
+
+	wp_cache_set( 'last_changed', microtime(), 'networks' );
+}
+
+/**
+ * Updates the network cache of given networks.
+ *
+ * Will add the networks in $networks to the cache. If network ID already exists
+ * in the network cache then it will not be updated. The network is added to the
+ * cache using the network group with the key using the ID of the networks.
+ *
+ * @since 4.6.0
+ *
+ * @param array $networks Array of network row objects.
+ */
+function update_network_cache( $networks ) {
+	foreach ( (array) $networks as $network ) {
+		wp_cache_add( $network->id, $network, 'networks' );
+	}
+}
+
+/**
+ * Adds any networks from the given IDs to the cache that do not already exist in cache.
+ *
+ * @since 4.6.0
+ * @access private
+ *
+ * @see update_network_cache()
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param array $network_ids Array of network IDs.
+ */
+function _prime_network_caches( $network_ids ) {
+	global $wpdb;
+
+	$non_cached_ids = _get_non_cached_ids( $network_ids, 'networks' );
+	if ( !empty( $non_cached_ids ) ) {
+		$fresh_networks = $wpdb->get_results( sprintf( "SELECT $wpdb->site.* FROM $wpdb->site WHERE id IN (%s)", join( ",", array_map( 'intval', $non_cached_ids ) ) ) );
+
+		update_network_cache( $fresh_networks );
+	}
+}
Index: src/wp-includes/ms-site.php
===================================================================
--- src/wp-includes/ms-site.php	(nonexistent)
+++ src/wp-includes/ms-site.php	(working copy)
@@ -0,0 +1,191 @@
+<?php
+/**
+ * Site API
+ *
+ * @package WordPress
+ * @subpackage Multisite
+ * @since 4.8.0
+ */
+
+/**
+ * Retrieves a list of sites matching requested arguments.
+ *
+ * @since 4.6.0
+ * @since 4.8.0 Introduced the 'lang_id', 'lang__in', and 'lang__not_in' parameters.
+ *
+ * @see WP_Site_Query::parse_query()
+ *
+ * @param string|array $args {
+ *     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' (returns an array of site IDs)
+ *                                           or empty (returns an array of complete site objects). Default empty.
+ *     @type int          $ID                A site ID to only return that site. Default empty.
+ *     @type int          $number            Maximum number of sites to retrieve. Default 100.
+ *     @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 int          $network_id        Limit results to those affiliated with a given network ID. If 0,
+ *                                           include all networks. Default 0.
+ *     @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       $domain            Limit results to those affiliated with a given domain. Default empty.
+ *     @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 path. Default empty.
+ *     @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          $public            Limit results to public sites. Accepts '1' or '0'. Default empty.
+ *     @type int          $archived          Limit results to archived sites. Accepts '1' or '0'. Default empty.
+ *     @type int          $mature            Limit results to mature sites. Accepts '1' or '0'. Default empty.
+ *     @type int          $spam              Limit results to spam sites. Accepts '1' or '0'. Default empty.
+ *     @type int          $deleted           Limit results to deleted sites. Accepts '1' or '0'. Default empty.
+ *     @type int          $lang_id           Limit results to a language ID. Default empty.
+ *     @type array        $lang__in          Array of language IDs to include affiliated sites for. Default empty.
+ *     @type array        $lang__not_in      Array of language IDs to exclude affiliated sites for. Default empty.
+ *     @type string       $search            Search term(s) to retrieve matching sites for. Default empty.
+ *     @type array        $search_columns    Array of column names to be searched. Accepts 'domain' and 'path'.
+ *                                           Default empty array.
+ *     @type bool         $update_site_cache Whether to prime the cache for found sites. Default false.
+ * }
+ * @return array List of sites.
+ */
+function get_sites( $args = array() ) {
+	$query = new WP_Site_Query();
+
+	return $query->query( $args );
+}
+
+/**
+ * Retrieves site data given a site ID or site object.
+ *
+ * Site data will be cached and returned after being passed through a filter.
+ * If the provided site is empty, the current site global will be used.
+ *
+ * @since 4.6.0
+ *
+ * @param WP_Site|int|null $site Optional. Site to retrieve. Default is the current site.
+ * @return WP_Site|null The site object or null if not found.
+ */
+function get_site( $site = null ) {
+	if ( empty( $site ) ) {
+		$site = get_current_blog_id();
+	}
+
+	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 WP_Site $_site Site data.
+	 */
+	$_site = apply_filters( 'get_site', $_site );
+
+	return $_site;
+}
+
+/**
+ * Clean the blog cache
+ *
+ * @since 3.5.0
+ *
+ * @global bool $_wp_suspend_cache_invalidation
+ *
+ * @param WP_Site $blog The site object to be cleared from cache.
+ */
+function clean_blog_cache( $blog ) {
+	global $_wp_suspend_cache_invalidation;
+
+	if ( ! empty( $_wp_suspend_cache_invalidation ) ) {
+		return;
+	}
+
+	$blog_id = $blog->blog_id;
+	$domain_path_key = md5( $blog->domain . $blog->path );
+
+	wp_cache_delete( $blog_id, 'sites' );
+	wp_cache_delete( $blog_id, 'site-details' );
+	wp_cache_delete( $blog_id, 'blog-details' );
+	wp_cache_delete( $blog_id . 'short' , 'blog-details' );
+	wp_cache_delete( $domain_path_key, 'blog-lookup' );
+	wp_cache_delete( $domain_path_key, 'blog-id-cache' );
+	wp_cache_delete( 'current_blog_' . $blog->domain, 'site-options' );
+	wp_cache_delete( 'current_blog_' . $blog->domain . $blog->path, 'site-options' );
+
+	/**
+	 * Fires immediately after a site has been removed from the object cache.
+	 *
+	 * @since 4.6.0
+	 *
+	 * @param int     $id              Blog ID.
+	 * @param WP_Site $blog            Site object.
+	 * @param string  $domain_path_key md5 hash of domain and path.
+	 */
+	do_action( 'clean_site_cache', $blog_id, $blog, $domain_path_key );
+
+	wp_cache_set( 'last_changed', microtime(), 'sites' );
+}
+
+/**
+ * Updates sites in cache.
+ *
+ * @since 4.6.0
+ *
+ * @param array $sites Array of site objects.
+ */
+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' );
+	}
+}
+
+/**
+ * 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( ",", array_map( 'intval', $non_cached_ids ) ) ) );
+
+		update_site_cache( $fresh_sites );
+	}
+}
