Changeset 53941

Timestamp:

08/25/2022 04:21:40 AM (2 years ago)

Author:

peterwilsoncc

Message:

Query: Cache post ID database query within WP_Query.

Add object caching to the first database query in WP_Query, ie the database query for post IDs that match the desired result. Randomly ordered queries remain uncached as they are not intended to return consistent results.

Caching of ID queries is enabled by default, per the post object, term and meta caches.

Props spacedmonkey, aaroncampbell, batmoo, chriscct7, costdev, dd32, drewapicture, johnbillion, mukesh27, nacin, ocean90, peterwilsoncc, ryan, scribu, sergeybiryukov, tillkruss.
Fixes #22176.

Location:

trunk

Files:

• src/wp-includes/class-wp-query.php (modified) (7 diffs)
• tests/phpunit/tests/query/cacheResults.php (added)
• tests/phpunit/tests/query/commentFeed.php (modified) (2 diffs)

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

@@ -1875 +1875 @@
 
         if ( ! isset( $q['cache_results'] ) ) {
-            if ( wp_using_ext_object_cache() ) {
-                $q['cache_results'] = false;
-            } else {
-                $q['cache_results'] = true;
-            }
+            $q['cache_results'] = true;
         }
 
@@ -3073 +3069 @@
         $this->posts = apply_filters_ref_array( 'posts_pre_query', array( null, &$this ) );
 
+        /*
+         * Ensure the ID database query is able to be cached.
+         *
+         * Random queries are expected to have unpredictable results and
+         * cannot be cached. Note the space before `RAND` in the string
+         * search, that to ensure against a collision with another
+         * function.
+         */
+        $id_query_is_cacheable = ! str_contains( strtoupper( $orderby ), ' RAND(' );
+        if ( $q['cache_results'] && $id_query_is_cacheable ) {
+            $cache_args = $q;
+
+            unset(
+                $cache_args['suppress_filters'],
+                $cache_args['cache_results'],
+                $cache_args['fields'],
+                $cache_args['update_post_meta_cache'],
+                $cache_args['update_post_term_cache'],
+                $cache_args['lazy_load_term_meta'],
+                $cache_args['update_menu_item_cache']
+            );
+
+            $new_request = str_replace( $fields, "{$wpdb->posts}.*", $this->request );
+            $key         = md5( serialize( $cache_args ) . $new_request );
+
+            $last_changed = wp_cache_get_last_changed( 'posts' );
+            if ( ! empty( $this->tax_query->queried_terms ) ) {
+                $last_changed .= wp_cache_get_last_changed( 'terms' );
+            }
+
+            $cache_key = "wp_query:$key:$last_changed";
+
+            if ( null === $this->posts ) {
+                $cached_results = wp_cache_get( $cache_key, 'posts' );
+
+                if ( $cached_results ) {
+                    if ( 'ids' === $q['fields'] ) {
+                        /** @var int[] */
+                        $this->posts = array_map( 'intval', $cached_results['posts'] );
+                    } else {
+                        _prime_post_caches( $cached_results['posts'], $q['update_post_term_cache'], $q['update_post_meta_cache'] );
+                        /** @var WP_Post[] */
+                        $this->posts = array_map( 'get_post', $cached_results['posts'] );
+                    }
+
+                    $this->post_count    = count( $this->posts );
+                    $this->found_posts   = $cached_results['found_posts'];
+                    $this->max_num_pages = $cached_results['max_num_pages'];
+
+                    if ( 'ids' === $q['fields'] ) {
+                        return $this->posts;
+                    } elseif ( 'id=>parent' === $q['fields'] ) {
+                        /** @var int[] */
+                        $post_parents = array();
+
+                        foreach ( $this->posts as $key => $post ) {
+                            $obj              = new stdClass();
+                            $obj->ID          = (int) $post->ID;
+                            $obj->post_parent = (int) $post->post_parent;
+
+                            $this->posts[ $key ] = $obj;
+
+                            $post_parents[ $obj->ID ] = $obj->post_parent;
+                        }
+
+                        return $post_parents;
+                    }
+                }
+            }
+        }
+
         if ( 'ids' === $q['fields'] ) {
             if ( null === $this->posts ) {
@@ -3083 +3150 @@
             $this->set_found_posts( $q, $limits );
 
+            if ( $q['cache_results'] && $id_query_is_cacheable ) {
+                $cache_value = array(
+                    'posts'         => $this->posts,
+                    'found_posts'   => $this->found_posts,
+                    'max_num_pages' => $this->max_num_pages,
+                );
+
+                wp_cache_set( $cache_key, $cache_value, 'posts' );
+            }
+
             return $this->posts;
         }
@@ -3095 +3172 @@
 
             /** @var int[] */
-            $r = array();
+            $post_parents = array();
+            $post_ids     = array();
+
             foreach ( $this->posts as $key => $post ) {
                 $this->posts[ $key ]->ID          = (int) $post->ID;
                 $this->posts[ $key ]->post_parent = (int) $post->post_parent;
 
-                $r[ (int) $post->ID ] = (int) $post->post_parent;
-            }
-
-            return $r;
+                $post_parents[ (int) $post->ID ] = (int) $post->post_parent;
+                $post_ids[]                      = (int) $post->ID;
+            }
+
+            if ( $q['cache_results'] && $id_query_is_cacheable ) {
+                $cache_value = array(
+                    'posts'         => $post_ids,
+                    'found_posts'   => $this->found_posts,
+                    'max_num_pages' => $this->max_num_pages,
+                );
+
+                wp_cache_set( $cache_key, $cache_value, 'posts' );
+            }
+
+            return $post_parents;
         }
 
@@ -3145 +3235 @@
                 $this->request = apply_filters( 'posts_request_ids', $this->request, $this );
 
-                $ids = $wpdb->get_col( $this->request );
-
-                if ( $ids ) {
-                    $this->posts = $ids;
+                $post_ids = $wpdb->get_col( $this->request );
+
+                if ( $post_ids ) {
+                    $this->posts = $post_ids;
                     $this->set_found_posts( $q, $limits );
-                    _prime_post_caches( $ids, $q['update_post_term_cache'], $q['update_post_meta_cache'] );
+                    _prime_post_caches( $post_ids, $q['update_post_term_cache'], $q['update_post_meta_cache'] );
                 } else {
                     $this->posts = array();
@@ -3166 +3256 @@
         }
 
+        if ( $q['cache_results'] && $id_query_is_cacheable ) {
+            $post_ids = wp_list_pluck( $this->posts, 'ID' );
+
+            $cache_value = array(
+                'posts'         => $post_ids,
+                'found_posts'   => $this->found_posts,
+                'max_num_pages' => $this->max_num_pages,
+            );
+
+            wp_cache_set( $cache_key, $cache_value, 'posts' );
+        }
+
         if ( ! empty( $this->posts ) && $q['update_menu_item_cache'] ) {
             update_menu_item_cache( $this->posts );
@@ -3202 +3304 @@
             $comments_request = "SELECT {$wpdb->comments}.comment_ID FROM {$wpdb->comments} $cjoin $cwhere $cgroupby $corderby $climits";
 
-            $key          = md5( $comments_request );
-            $last_changed = wp_cache_get_last_changed( 'comment' );
-
-            $cache_key   = "comment_feed:$key:$last_changed";
-            $comment_ids = wp_cache_get( $cache_key, 'comment' );
+            $comment_key          = md5( $comments_request );
+            $comment_last_changed = wp_cache_get_last_changed( 'comment' );
+
+            $comment_cache_key = "comment_feed:$comment_key:$comment_last_changed";
+            $comment_ids       = wp_cache_get( $comment_cache_key, 'comment' );
             if ( false === $comment_ids ) {
                 $comment_ids = $wpdb->get_col( $comments_request );
-                wp_cache_add( $cache_key, $comment_ids, 'comment' );
+                wp_cache_add( $comment_cache_key, $comment_ids, 'comment' );
             }
             _prime_comment_caches( $comment_ids, false );

trunk/tests/phpunit/tests/query/commentFeed.php

@@ -40 +40 @@
             'ignore_sticky_posts'    => false,
             'no_found_rows'          => true,
+            'cache_results'          => false,
         );
         $q1->query( $args );
@@ -99 +100 @@
             'update_post_term_cache' => false,
             'ignore_sticky_posts'    => false,
+            'cache_results'          => false,
         );