Multisite: Introduce ms-site.php and ms-network.php files.

By providing distinct files for the site and network APIs, a better overview is provided. Prior to this change, the `ms-blogs.php` file had grown too big, mixing site APIs, network APIs and related legacy APIs that need to be maintained. Since multisite is often used in unexpected ways, backward-compatibility is ensured by including the two new files from `ms-blogs.php`, which previously contained all functions that have been moved to the new files.

This changeset does not contain any functional changes.

Fixes #40647.


git-svn-id: https://develop.svn.wordpress.org/trunk@44472 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/ms-network.php

@@ -0,0 +1,138 @@
+<?php
+/**
+ * Network API
+ *
+ * @package WordPress
+ * @subpackage Multisite
+ * @since 5.1.0
+ */
+
+/**
+ * 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;
+}
+
+/**
+ * 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 array|int List of WP_Network objects, a list of network ids when 'fields' is set to 'ids',
+ *                   or the number of networks when 'count' is passed as a query var.
+ */
+function get_networks( $args = array() ) {
+	$query = new WP_Network_Query();
+
+	return $query->query( $args );
+}
+
+/**
+ * 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 ) ) ) ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
+
+		update_network_cache( $fresh_networks );
+	}
+}