Multisite: Improve initializing available roles when switch sites.

Switching the available roles and the current user's capabilities no longer happens in `switch_to_blog()` and `restore_current_blog()`, instead it has been moved to a new function `wp_switch_roles_and_user()` which is hooked into the site switching process. This allows to improve performance by temporarily unhooking the function when roles and capabilities do not need to be switched.

This change ensures that switching available roles now works closer to switching user capabilities, particularly the changes in [41624]. A new `WP_Roles::for_site( $site_id )` method has been introduced, and the `WP_Roles::_init()` method has been deprecated. It is furthermore possible to retrieve the site ID for which the available roles are currently initialized through a new `WP_Roles::get_site_id()`.

Props johnjamesjacoby, flixos90.
Fixes #38645.

Built from https://develop.svn.wordpress.org/trunk@41625


git-svn-id: http://core.svn.wordpress.org/trunk@41460 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-roles.php

@@ -64,13 +64,30 @@ class WP_Roles {
 	 */
 	public $use_db = true;
 
+	/**
+	 * The site ID the roles are initialized for.
+	 *
+	 * @since 4.9.0
+	 * @var int
+	 */
+	protected $site_id = 0;
+
 	/**
 	 * Constructor
 	 *
 	 * @since 2.0.0
+	 * @since 4.9.0 The $site_id argument was added.
+	 *
+	 * @global array $wp_user_roles Used to set the 'roles' property value.
+	 *
+	 * @param int $site_id Site ID to initialize roles for. Default is the current site.
 	 */
-	public function __construct() {
-		$this->_init();
+	public function __construct( $site_id = null ) {
+		global $wp_user_roles;
+
+		$this->use_db = empty( $wp_user_roles );
+
+		$this->for_site( $site_id );
 	}
 
 	/**
@@ -97,38 +114,12 @@ class WP_Roles {
 	 * be used and the role option will not be updated or used.
 	 *
 	 * @since 2.1.0
-	 *
-	 * @global array $wp_user_roles Used to set the 'roles' property value.
+	 * @deprecated 4.9.0 Use WP_Roles::for_site()
 	 */
 	protected function _init() {
-		global $wp_user_roles, $wpdb;
+		_deprecated_function( __METHOD__, '4.9.0', 'WP_Roles::for_site()' );
 
-		$this->role_key = $wpdb->get_blog_prefix() . 'user_roles';
-		if ( ! empty( $wp_user_roles ) ) {
-			$this->roles = $wp_user_roles;
-			$this->use_db = false;
-		} else {
-			$this->roles = get_option( $this->role_key );
-		}
-
-		if ( empty( $this->roles ) )
-			return;
-
-		$this->role_objects = array();
-		$this->role_names =  array();
-		foreach ( array_keys( $this->roles ) as $role ) {
-			$this->role_objects[$role] = new WP_Role( $role, $this->roles[$role]['capabilities'] );
-			$this->role_names[$role] = $this->roles[$role]['name'];
-		}
-
-		/**
-		 * After the roles have been initialized, allow plugins to add their own roles.
-		 *
-		 * @since 4.7.0
-		 *
-		 * @param WP_Roles $this A reference to the WP_Roles object.
-		 */
-		do_action( 'wp_roles_init', $this );
+		$this->for_site();
 	}
 
 	/**
@@ -138,11 +129,12 @@ class WP_Roles {
 	 * after switching wpdb to a new site ID.
 	 *
 	 * @since 3.5.0
-	 * @deprecated 4.7.0 Use new WP_Roles()
+	 * @deprecated 4.7.0 Use WP_Roles::for_site()
 	 */
 	public function reinit() {
-		_deprecated_function( __METHOD__, '4.7.0', 'new WP_Roles()' );
-		$this->_init();
+		_deprecated_function( __METHOD__, '4.7.0', 'WP_Roles::for_site()' );
+
+		$this->for_site();
 	}
 
 	/**
@@ -270,4 +262,100 @@ class WP_Roles {
 	public function is_role( $role ) {
 		return isset( $this->role_names[$role] );
 	}
+
+	/**
+	 * Initializes all of the available roles.
+	 *
+	 * @since 4.9.0
+	 */
+	public function init_roles() {
+		if ( empty( $this->roles ) ) {
+			return;
+		}
+
+		$this->role_objects = array();
+		$this->role_names =  array();
+		foreach ( array_keys( $this->roles ) as $role ) {
+			$this->role_objects[ $role ] = new WP_Role( $role, $this->roles[ $role ]['capabilities'] );
+			$this->role_names[ $role ] = $this->roles[ $role ]['name'];
+		}
+
+		/**
+		 * After the roles have been initialized, allow plugins to add their own roles.
+		 *
+		 * @since 4.7.0
+		 *
+		 * @param WP_Roles $this A reference to the WP_Roles object.
+		 */
+		do_action( 'wp_roles_init', $this );
+	}
+
+	/**
+	 * Sets the site to operate on. Defaults to the current site.
+	 *
+	 * @since 4.9.0
+	 *
+	 * @global wpdb $wpdb WordPress database abstraction object.
+	 *
+	 * @param int $site_id Site ID to initialize roles for. Default is the current site.
+	 */
+	public function for_site( $site_id = null ) {
+		global $wpdb;
+
+		if ( ! empty( $site_id ) ) {
+			$this->site_id = absint( $site_id );
+		} else {
+			$this->site_id = get_current_blog_id();
+		}
+
+		$this->role_key = $wpdb->get_blog_prefix( $this->site_id ) . 'user_roles';
+
+		if ( ! empty( $this->roles ) && ! $this->use_db ) {
+			return;
+		}
+
+		$this->roles = $this->get_roles_data();
+
+		$this->init_roles();
+	}
+
+	/**
+	 * Gets the ID of the site for which roles are currently initialized.
+	 *
+	 * @since 4.9.0
+	 *
+	 * @return int Site ID.
+	 */
+	public function get_site_id() {
+		return $this->site_id;
+	}
+
+	/**
+	 * Gets the available roles data.
+	 *
+	 * @since 4.9.0
+	 *
+	 * @global array $wp_user_roles Used to set the 'roles' property value.
+	 *
+	 * @return array Roles array.
+	 */
+	protected function get_roles_data() {
+		global $wp_user_roles;
+
+		if ( ! empty( $wp_user_roles ) ) {
+			return $wp_user_roles;
+		}
+
+		if ( is_multisite() && $this->site_id != get_current_blog_id() ) {
+			remove_action( 'switch_blog', 'wp_switch_roles_and_user', 1 );
+
+			$roles = get_blog_option( $this->site_id, $this->role_key, array() );
+
+			add_action( 'switch_blog', 'wp_switch_roles_and_user', 1, 2 );
+
+			return $roles;
+		}
+
+		return get_option( $this->role_key, array() );
+	}
 }

wp-includes/ms-blogs.php

@@ -792,7 +792,7 @@ function update_blog_option( $id, $option, $value, $deprecated = null ) {
  * @return true Always returns True.
  */
 function switch_to_blog( $new_blog, $deprecated = null ) {
-	global $wpdb, $wp_roles;
+	global $wpdb;
 
 	$blog_id = get_current_blog_id();
 	if ( empty( $new_blog ) ) {
@@ -847,12 +847,6 @@ function switch_to_blog( $new_blog, $deprecated = null ) {
 		}
 	}
 
-	if ( did_action( 'init' ) ) {
-		$wp_roles = new WP_Roles();
-		$current_user = wp_get_current_user();
-		$current_user->for_site( $new_blog );
-	}
-
 	/** This filter is documented in wp-includes/ms-blogs.php */
 	do_action( 'switch_blog', $new_blog, $prev_blog_id );
 	$GLOBALS['switched'] = true;
@@ -876,7 +870,7 @@ function switch_to_blog( $new_blog, $deprecated = null ) {
  * @return bool True on success, false if we're already on the current blog
  */
 function restore_current_blog() {
-	global $wpdb, $wp_roles;
+	global $wpdb;
 
 	if ( empty( $GLOBALS['_wp_switched_stack'] ) ) {
 		return false;
@@ -921,12 +915,6 @@ function restore_current_blog() {
 		}
 	}
 
-	if ( did_action( 'init' ) ) {
-		$wp_roles = new WP_Roles();
-		$current_user = wp_get_current_user();
-		$current_user->for_site( $blog );
-	}
-
 	/** This filter is documented in wp-includes/ms-blogs.php */
 	do_action( 'switch_blog', $blog, $prev_blog_id );
 
@@ -936,6 +924,27 @@ function restore_current_blog() {
 	return true;
 }
 
+/**
+ * Switches the initialized roles and current user capabilities to another site.
+ *
+ * @since 4.9.0
+ *
+ * @param int $new_site_id New site ID.
+ * @param int $old_site_id Old site ID.
+ */
+function wp_switch_roles_and_user( $new_site_id, $old_site_id ) {
+	if ( $new_site_id == $old_site_id ) {
+		return;
+	}
+
+	if ( ! did_action( 'init' ) ) {
+		return;
+	}
+
+	wp_roles()->for_site( $new_site_id );
+	wp_get_current_user()->for_site( $new_site_id );
+}
+
 /**
  * Determines if switch_to_blog() is in effect
  *

wp-includes/ms-default-filters.php

@@ -32,6 +32,9 @@ add_action( 'network_site_users_created_user', 'wp_send_new_user_notifications'
 add_action( 'network_user_new_created_user',   'wp_send_new_user_notifications' );
 add_filter( 'sanitize_user', 'strtolower' );
 
+// Roles
+add_action( 'switch_blog', 'wp_switch_roles_and_user', 1, 2 );
+
 // Blogs
 add_filter( 'wpmu_validate_blog_signup', 'signup_nonce_check' );
 add_action( 'wpmu_new_blog', 'wpmu_log_new_registrations', 10, 2 );

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.9-alpha-41624';
+$wp_version = '4.9-alpha-41625';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.