Merge "Change Title::getPreviousRevisionID (and next) to ignore PRIMARY"

[lhc/web/wiklou.git] / includes / Title.php

diff --git a/includes/Title.php b/includes/Title.php
index a5bb9c6..e45994c 100644 (file)
--- a/includes/Title.php
+++ b/includes/Title.php
@@ -3961,14 +3961,22 @@ class Title implements LinkTarget {
         * @return int|bool Old revision ID, or false if none exists
         */
        public function getPreviousRevisionID( $revId, $flags = 0 ) {
-               $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_REPLICA );
+               /* This function and getNextRevisionID have bad performance when
+                  used on a page with many revisions on mysql. An explicit extended
+                  primary key may help in some cases, if the PRIMARY KEY is banned:
+                  T159319 */
+               if ( $flags & self::GAID_FOR_UPDATE ) {
+                       $db = wfGetDB( DB_MASTER );
+               } else {
+                       $db = wfGetDB( DB_REPLICA, 'contributions' );
+               }
                $revId = $db->selectField( 'revision', 'rev_id',
                        [
                                'rev_page' => $this->getArticleID( $flags ),
                                'rev_id < ' . intval( $revId )
                        ],
                        __METHOD__,
-                       [ 'ORDER BY' => 'rev_id DESC' ]
+                       [ 'ORDER BY' => 'rev_id DESC', 'IGNORE INDEX' => 'PRIMARY' ]
                );
 
                if ( $revId === false ) {
@@ -3986,14 +3994,18 @@ class Title implements LinkTarget {
         * @return int|bool Next revision ID, or false if none exists
         */
        public function getNextRevisionID( $revId, $flags = 0 ) {
-               $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_REPLICA );
+               if ( $flags & self::GAID_FOR_UPDATE ) {
+                       $db = wfGetDB( DB_MASTER );
+               } else {
+                       $db = wfGetDB( DB_REPLICA, 'contributions' );
+               }
                $revId = $db->selectField( 'revision', 'rev_id',
                        [
                                'rev_page' => $this->getArticleID( $flags ),
                                'rev_id > ' . intval( $revId )
                        ],
                        __METHOD__,
-                       [ 'ORDER BY' => 'rev_id' ]
+                       [ 'ORDER BY' => 'rev_id', 'IGNORE INDEX' => 'PRIMARY' ]
                );
 
                if ( $revId === false ) {