Lazy load user capabilities in WP_User object

src/wp-includes/class-wp-metadata-lazyloader.php

@@ -65,6 +65,10 @@ public function __construct() {
 				'filter'   => 'get_blog_metadata',
 				'callback' => array( $this, 'lazyload_meta_callback' ),
 			),
+			'user'    => array(
+				'filter'   => 'get_user_metadata',
+				'callback' => array( $this, 'lazyload_meta_callback' ),
+			),
 		);
 	}
 

src/wp-includes/class-wp-user.php

@@ -61,7 +61,7 @@ class WP_User {
 	 * @var bool[] Array of key/value pairs where keys represent a capability name
 	 *             and boolean values represent whether the user has that capability.
 	 */
-	public $caps = array();
+	protected $caps = array();
 
 	/**
 	 * User metadata option name.
@@ -77,7 +77,7 @@ class WP_User {
 	 * @since 2.0.0
 	 * @var string[]
 	 */
-	public $roles = array();
+	protected $roles = array();
 
 	/**
 	 * All capabilities the user has, including individual and role based.
@@ -86,7 +86,7 @@ class WP_User {
 	 * @var bool[] Array of key/value pairs where keys represent a capability name
 	 *             and boolean values represent whether the user has that capability.
 	 */
-	public $allcaps = array();
+	protected $allcaps = array();
 
 	/**
 	 * The filter context applied to user data fields.
@@ -104,6 +104,9 @@ class WP_User {
 	 */
 	private $site_id = 0;
 
+
+	private $loaded_caps = false;
+
 	/**
 	 * @since 3.3.0
 	 * @var array
@@ -286,6 +289,10 @@ public function __isset( $key ) {
 			$key = 'ID';
 		}
 
+		if ( in_array( $key, array( 'caps', 'allcaps', 'roles' ), true ) ) {
+			return isset( $this->$key );
+		}
+
 		if ( isset( $this->data->$key ) ) {
 			return true;
 		}
@@ -319,6 +326,11 @@ public function __get( $key ) {
 			return $this->ID;
 		}
 
+		if ( in_array( $key, array( 'caps', 'allcaps', 'roles' ), true ) ) {
+			$this->load_capablity_data();
+			return $this->$key;
+		}
+
 		if ( isset( $this->data->$key ) ) {
 			$value = $this->data->$key;
 		} else {
@@ -513,6 +525,10 @@ public function get_role_caps() {
 
 		$wp_roles = wp_roles();
 
+		if ( ! $this->loaded_caps ) {
+			$this->caps = $this->get_caps_data();
+		}
+
 		// Filter out caps that are not role names and assign to $this->roles.
 		if ( is_array( $this->caps ) ) {
 			$this->roles = array_filter( array_keys( $this->caps ), array( $wp_roles, 'is_role' ) );
@@ -546,6 +562,7 @@ public function add_role( $role ) {
 		if ( empty( $role ) ) {
 			return;
 		}
+		$this->load_capablity_data();
 
 		if ( in_array( $role, $this->roles, true ) ) {
 			return;
@@ -575,6 +592,7 @@ public function add_role( $role ) {
 	 * @param string $role Role name.
 	 */
 	public function remove_role( $role ) {
+		$this->load_capablity_data();
 		if ( ! in_array( $role, $this->roles, true ) ) {
 			return;
 		}
@@ -607,6 +625,7 @@ public function remove_role( $role ) {
 	 * @param string $role Role name.
 	 */
 	public function set_role( $role ) {
+		$this->load_capablity_data();
 		if ( 1 === count( $this->roles ) && current( $this->roles ) === $role ) {
 			return;
 		}
@@ -708,6 +727,7 @@ public function update_user_level_from_caps() {
 	 * @param bool   $grant Whether to grant capability to user.
 	 */
 	public function add_cap( $cap, $grant = true ) {
+		$this->load_capablity_data();
 		$this->caps[ $cap ] = $grant;
 		update_user_meta( $this->ID, $this->cap_key, $this->caps );
 		$this->get_role_caps();
@@ -722,6 +742,7 @@ public function add_cap( $cap, $grant = true ) {
 	 * @param string $cap Capability name.
 	 */
 	public function remove_cap( $cap ) {
+		$this->load_capablity_data();
 		if ( ! isset( $this->caps[ $cap ] ) ) {
 			return;
 		}
@@ -774,6 +795,8 @@ public function remove_all_caps() {
 	 *              the given capability for that object.
 	 */
 	public function has_cap( $cap, ...$args ) {
+		$this->load_capablity_data();
+
 		if ( is_numeric( $cap ) ) {
 			_deprecated_argument( __FUNCTION__, '2.0.0', __( 'Usage of user levels is deprecated. Use capabilities instead.' ) );
 			$cap = $this->translate_level_to_cap( $cap );
@@ -876,9 +899,7 @@ public function for_site( $site_id = '' ) {
 
 		$this->cap_key = $wpdb->get_blog_prefix( $this->site_id ) . 'capabilities';
 
-		$this->caps = $this->get_caps_data();
-
-		$this->get_role_caps();
+		wp_lazyload_user_meta( array( $this->ID ) );
 	}
 
 	/**
@@ -909,4 +930,17 @@ private function get_caps_data() {
 
 		return $caps;
 	}
+
+	/**
+	 * Load capability data.
+	 *
+	 * @since 6.4.0
+	 */
+	private function load_capablity_data() {
+		if ( ! $this->loaded_caps ) {
+			$this->caps = $this->get_caps_data();
+			$this->get_role_caps();
+			$this->loaded_caps = true;
+		}
+	}
 }

src/wp-includes/pluggable.php

@@ -125,7 +125,7 @@ function get_user_by( $field, $value ) {
 	function cache_users( $user_ids ) {
 		global $wpdb;
 
-		update_meta_cache( 'user', $user_ids );
+		wp_lazyload_user_meta( $user_ids );
 
 		$clean = _get_non_cached_ids( $user_ids, 'users' );
 

src/wp-includes/user.php

@@ -1205,6 +1205,21 @@ function get_user_meta( $user_id, $key = '', $single = false ) {
 	return get_metadata( 'user', $user_id, $key, $single );
 }
 
+/**
+ * Queue user meta for lazy-loading.
+ *
+ * @since 6.4.0
+ *
+ * @param array $user_ids List of user IDs.
+ */
+function wp_lazyload_user_meta( array $user_ids ) {
+	if ( empty( $user_ids ) ) {
+		return;
+	}
+	$lazyloader = wp_metadata_lazyloader();
+	$lazyloader->queue_objects( 'user', $user_ids );
+}
+
 /**
  * Updates user meta field based on user ID.
  *

tests/phpunit/includes/abstract-testcase.php

@@ -288,6 +288,7 @@ protected function reset_lazyload_queue() {
 		$lazyloader->reset_queue( 'term' );
 		$lazyloader->reset_queue( 'comment' );
 		$lazyloader->reset_queue( 'blog' );
+		$lazyloader->reset_queue( 'user' );
 	}
 
 	/**

tests/phpunit/tests/post/updatePostAuthorCaches.php

@@ -66,6 +66,9 @@ public function test_update_post_author_caches() {
 		while ( $q->have_posts() ) {
 			$q->the_post();
 		}
+		foreach ( self::$user_ids as $user_id ) {
+			get_user_meta( $user_id );
+		}
 
 		$args      = $action->get_args();
 		$last_args = end( $args );

tests/phpunit/tests/query/cacheResults.php

@@ -1577,11 +1577,10 @@ public function test_author_cache_warmed_by_the_loop( $fields ) {
 		$query_1->the_post();
 		$num_loop_queries = get_num_queries() - $start_loop_queries;
 		/*
-		 * Two expected queries:
+		 * One expected queries:
 		 * 1: User meta data,
-		 * 2: User data.
 		 */
-		$this->assertSame( 2, $num_loop_queries, 'Unexpected number of queries while initializing the loop.' );
+		$this->assertSame( 1, $num_loop_queries, 'Unexpected number of queries while initializing the loop.' );
 
 		$start_author_queries = get_num_queries();
 		get_user_by( 'ID', self::$author_id );

tests/phpunit/tests/user/query.php

@@ -159,16 +159,22 @@ public function test_get_all() {
 	 * @ticket 55594
 	 */
 	public function test_get_all_primed_users() {
+		$this->reset_lazyload_queue();
 		$filter = new MockAction();
 		add_filter( 'update_user_metadata_cache', array( $filter, 'filter' ), 10, 2 );
 
-		new WP_User_Query(
+		$query = new WP_User_Query(
 			array(
 				'include' => self::$author_ids,
 				'fields'  => 'all',
 			)
 		);
 
+		$users = $query->get_results();
+		foreach ( $users as $user ) {
+			$user->roles;
+		}
+
 		$args      = $filter->get_args();
 		$last_args = end( $args );
 		$this->assertIsArray( $last_args[1] );