Ticket #15400: 15400-2-reduce-queries-to-number-of-posts-when-pagination-enable.patch

wp-includes/comment.php

@@ -792 +792 @@
                 'trackback' => 'trackback',
         );
 
-        $comtypewhere = ( 'all' != $args['type'] && isset($allowedtypes[$args['type']]) ) ? " AND comment_type = '" . $allowedtypes[$args['type']] . "'" : '';
 
-        // Count comments older than this one
-        $oldercoms = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(comment_ID) FROM $wpdb->comments WHERE comment_post_ID = %d AND comment_parent = 0 AND comment_approved = '1' AND comment_date_gmt < '%s'" . $comtypewhere, $comment->comment_post_ID, $comment->comment_date_gmt ) );
+        if ( ($comsdatebypost = wp_cache_get( $comment->comment_post_ID, 'page_of_comment' )) == false ) {
+                $comtypewhere = ( 'all' != $args['type'] && isset($allowedtypes[$args['type']]) ) ? " AND comment_type = '" . $allowedtypes[$args['type']] . "'" : '';
 
+                // Count comments older than this one
+                $comslist = $wpdb->get_results( $wpdb->prepare( "SELECT comment_date_gmt FROM $wpdb->comments WHERE comment_post_ID = %d AND comment_parent = 0 AND comment_approved = '1'" . $comtypewhere, $comment->comment_post_ID ) );
+
+                $comsdatebypost = array();
+                foreach ($comslist as $pagecom) {
+                        $comsdatebypost[] =  strtotime( $pagecom->comment_date_gmt );
+                }
+                wp_cache_add( $comment->comment_post_ID, $comsdatebypost,  'page_of_comment' );
+        }
+        
+        $oldercoms = 0;
+        
+        foreach($comsdatebypost as $comdate) {
+                if( $comdate < strtotime($comment->comment_date_gmt) ) {
+                        $oldercoms++;
+                }
+        }
+
         // No older comments? Then it's page #1.
         if ( 0 == $oldercoms )
                 return 1;