WP-r55657: Users: Cache database queries within WP_User_Query class

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

@@ -119,6 +119,7 @@ public static function fill_query_vars( $args ) {
 			'login'               => '',
 			'login__in'           => array(),
 			'login__not_in'       => array(),
+			'cache_results'       => true,
 		);
 
 		return wp_parse_args( $args, $defaults );
@@ -140,6 +141,7 @@ public static function fill_query_vars( $args ) {
 	 * @since 5.1.0 Introduced the 'meta_compare_key' parameter.
 	 * @since 5.3.0 Introduced the 'meta_type_key' parameter.
 	 * @since 5.9.0 Added 'capability', 'capability__in', and 'capability__not_in' parameters.
+	 * @since 6.3.0 Added 'cache_results' parameter.
 	 *
 	 * @global wpdb     $wpdb     WordPress database abstraction object.
 	 * @global WP_Roles $wp_roles WordPress role management object.
@@ -254,6 +256,7 @@ public static function fill_query_vars( $args ) {
 	 *                                                logins will be included in results. Default empty array.
 	 *     @type string[]        $login__not_in       An array of logins to exclude. Users matching one of these
 	 *                                                logins will not be included in results. Default empty array.
+	 *     @type bool            $cache_results       Whether to cache user information. Default true.
 	 * }
 	 */
 	public function prepare_query( $query = array() ) {
@@ -790,6 +793,11 @@ public function query() {
 
 		$qv =& $this->query_vars;
 
+		// Do not cache results if more than 3 fields are requested.
+		if ( is_array( $qv['fields'] ) && count( $qv['fields'] ) > 3 ) {
+			$qv['cache_results'] = false;
+		}
+
 		/**
 		 * Filters the users array before the query takes place.
 		 *
@@ -816,28 +824,47 @@ public function query() {
 				{$this->query_orderby}
 				{$this->query_limit}
 			";
-
-			if ( is_array( $qv['fields'] ) ) {
-				$this->results = $wpdb->get_results( $this->request );
-			} else {
-				$this->results = $wpdb->get_col( $this->request );
+			$cache_value   = false;
+			$cache_key     = $this->generate_cache_key( $qv, $this->request );
+			$cache_group   = 'user-queries';
+			if ( $qv['cache_results'] ) {
+				$cache_value = wp_cache_get( $cache_key, $cache_group );
 			}
+			if ( false !== $cache_value ) {
+				$this->results     = $cache_value['user_data'];
+				$this->total_users = $cache_value['total_users'];
+			} else {
+
+				if ( is_array( $qv['fields'] ) ) {
+					$this->results = $wpdb->get_results( $this->request );
+				} else {
+					$this->results = $wpdb->get_col( $this->request );
+				}
+
+				if ( isset( $qv['count_total'] ) && $qv['count_total'] ) {
+					/**
+					 * Filters SELECT FOUND_ROWS() query for the current WP_User_Query instance.
+					 *
+					 * @since 3.2.0
+					 * @since 5.1.0 Added the `$this` parameter.
+					 *
+					 * @global wpdb $wpdb WordPress database abstraction object.
+					 *
+					 * @param string        $sql   The SELECT FOUND_ROWS() query for the current WP_User_Query.
+					 * @param WP_User_Query $query The current WP_User_Query instance.
+					 */
+					$found_users_query = apply_filters( 'found_users_query', 'SELECT FOUND_ROWS()', $this );
+
+					$this->total_users = (int) $wpdb->get_var( $found_users_query );
+				}
 
-			if ( isset( $qv['count_total'] ) && $qv['count_total'] ) {
-				/**
-				 * Filters SELECT FOUND_ROWS() query for the current WP_User_Query instance.
-				 *
-				 * @since 3.2.0
-				 * @since 5.1.0 Added the `$this` parameter.
-				 *
-				 * @global wpdb $wpdb WordPress database abstraction object.
-				 *
-				 * @param string        $sql   The SELECT FOUND_ROWS() query for the current WP_User_Query.
-				 * @param WP_User_Query $query The current WP_User_Query instance.
-				 */
-				$found_users_query = apply_filters( 'found_users_query', 'SELECT FOUND_ROWS()', $this );
-
-				$this->total_users = (int) $wpdb->get_var( $found_users_query );
+				if ( $qv['cache_results'] ) {
+					$cache_value = array(
+						'user_data'   => $this->results,
+						'total_users' => $this->total_users,
+					);
+					wp_cache_add( $cache_key, $cache_value, $cache_group );
+				}
 			}
 		}
 
@@ -1010,6 +1037,57 @@ protected function parse_orderby( $orderby ) {
 		return $_orderby;
 	}
 
+	/**
+	 * Generate cache key.
+	 *
+	 * @since 6.3.0
+	 *
+	 * @global wpdb $wpdb WordPress database abstraction object.
+	 *
+	 * @param array  $args Query arguments.
+	 * @param string $sql  SQL statement.
+	 * @return string Cache key.
+	 */
+	protected function generate_cache_key( array $args, $sql ) {
+		global $wpdb;
+
+		// Replace wpdb placeholder in the SQL statement used by the cache key.
+		$sql = $wpdb->remove_placeholder_escape( $sql );
+
+		$key          = md5( $sql );
+		$last_changed = wp_cache_get_last_changed( 'users' );
+
+		if ( empty( $args['orderby'] ) ) {
+			// Default order is by 'user_login'.
+			$ordersby = array( 'user_login' => '' );
+		} elseif ( is_array( $args['orderby'] ) ) {
+			$ordersby = $args['orderby'];
+		} else {
+			// 'orderby' values may be a comma- or space-separated list.
+			$ordersby = preg_split( '/[,\s]+/', $args['orderby'] );
+		}
+
+		$blog_id = 0;
+		if ( isset( $args['blog_id'] ) ) {
+			$blog_id = absint( $args['blog_id'] );
+		}
+
+		if ( $args['has_published_posts'] || in_array( 'post_count', $ordersby, true ) ) {
+			$switch = $blog_id && get_current_blog_id() !== $blog_id;
+			if ( $switch ) {
+				switch_to_blog( $blog_id );
+			}
+
+			$last_changed .= wp_cache_get_last_changed( 'posts' );
+
+			if ( $switch ) {
+				restore_current_blog();
+			}
+		}
+
+		return "get_users:$key:$last_changed";
+	}
+
 	/**
 	 * Parses an 'order' query variable and casts it to ASC or DESC as necessary.
 	 *

src/wp-includes/default-filters.php

@@ -115,6 +115,14 @@
 add_action( 'updated_post_meta', 'wp_cache_set_posts_last_changed' );
 add_action( 'deleted_post_meta', 'wp_cache_set_posts_last_changed' );
 
+// User meta.
+add_action( 'added_user_meta', 'wp_cache_set_users_last_changed' );
+add_action( 'updated_user_meta', 'wp_cache_set_users_last_changed' );
+add_action( 'deleted_user_meta', 'wp_cache_set_users_last_changed' );
+add_action( 'add_user_role', 'wp_cache_set_users_last_changed' );
+add_action( 'set_user_role', 'wp_cache_set_users_last_changed' );
+add_action( 'remove_user_role', 'wp_cache_set_users_last_changed' );
+
 // Term meta.
 add_action( 'added_term_meta', 'wp_cache_set_terms_last_changed' );
 add_action( 'updated_term_meta', 'wp_cache_set_terms_last_changed' );

src/wp-includes/load.php

@@ -765,6 +765,7 @@ function wp_start_object_cache() {
 				'site-transient',
 				'rss',
 				'users',
+				'user-queries',
 				'useremail',
 				'userlogins',
 				'usermeta',

src/wp-includes/ms-blogs.php

@@ -566,6 +566,7 @@ function switch_to_blog( $new_blog_id, $deprecated = null ) {
 						'site-transient',
 						'rss',
 						'users',
+						'user-queries',
 						'useremail',
 						'userlogins',
 						'usermeta',
@@ -657,6 +658,7 @@ function restore_current_blog() {
 						'site-transient',
 						'rss',
 						'users',
+						'user-queries',
 						'useremail',
 						'userlogins',
 						'usermeta',

src/wp-includes/ms-functions.php

@@ -295,6 +295,7 @@ function remove_user_from_blog( $user_id, $blog_id = 0, $reassign = 0 ) {
 		}
 	}
 
+	clean_user_cache( $user_id );
 	restore_current_blog();
 
 	return true;

src/wp-includes/user.php

@@ -1907,6 +1907,7 @@ function clean_user_cache( $user ) {
 	}
 
 	wp_cache_delete( $user->ID, 'user_meta' );
+	wp_cache_set_users_last_changed();
 
 	/**
 	 * Fires immediately after the given user's cache is cleaned.
@@ -4969,3 +4970,12 @@ function wp_is_application_passwords_available_for_user( $user ) {
 	 */
 	return apply_filters( 'wp_is_application_passwords_available_for_user', true, $user );
 }
+
+/**
+ * Sets the last changed time for the 'users' cache group.
+ *
+ * @since 6.3.0
+ */
+function wp_cache_set_users_last_changed() {
+	wp_cache_set( 'last_changed', microtime(), 'users' );
+}

tests/phpunit/includes/abstract-testcase.php

@@ -406,6 +406,7 @@ public static function flush_cache() {
 				'site-transient',
 				'rss',
 				'users',
+				'user-queries',
 				'useremail',
 				'userlogins',
 				'usermeta',