Avoid creating DB replication lag in clearAllNotifications()

Change-Id: Ifad51cf2aaa9867513615d48753436cf686d7f1c

diff --git a/includes/user/User.php b/includes/user/User.php
index 7109a4a..2af0324 100644 (file)
--- a/includes/user/User.php
+++ b/includes/user/User.php
@@ -3613,31 +3613,69 @@ class User implements IDBAccessObject {
         * @note If the user doesn't have 'editmywatchlist', this will do nothing.
         */
        public function clearAllNotifications() {
-               if ( wfReadOnly() ) {
-                       return;
-               }
-
+               global $wgUseEnotif, $wgShowUpdatedMarker;
                // Do nothing if not allowed to edit the watchlist
-               if ( !$this->isAllowed( 'editmywatchlist' ) ) {
+               if ( wfReadOnly() || !$this->isAllowed( 'editmywatchlist' ) ) {
                        return;
                }
 
-               global $wgUseEnotif, $wgShowUpdatedMarker;
                if ( !$wgUseEnotif && !$wgShowUpdatedMarker ) {
                        $this->setNewtalk( false );
                        return;
                }
+
                $id = $this->getId();
-               if ( $id != 0 ) {
-                       $dbw = wfGetDB( DB_MASTER );
-                       $dbw->update( 'watchlist',
-                               [ /* SET */ 'wl_notificationtimestamp' => null ],
-                               [ /* WHERE */ 'wl_user' => $id, 'wl_notificationtimestamp IS NOT NULL' ],
-                               __METHOD__
-                       );
-                       // We also need to clear here the "you have new message" notification for the own user_talk page;
-                       // it's cleared one page view later in WikiPage::doViewUpdates().
+               if ( !$id ) {
+                       return;
                }
+
+               $dbw = wfGetDB( DB_MASTER );
+               $asOfTimes = array_unique( $dbw->selectFieldValues(
+                       'watchlist',
+                       'wl_notificationtimestamp',
+                       [ 'wl_user' => $id, 'wl_notificationtimestamp IS NOT NULL' ],
+                       __METHOD__,
+                       [ 'ORDER BY' => 'wl_notificationtimestamp DESC', 'LIMIT' => 500 ]
+               ) );
+               if ( !$asOfTimes ) {
+                       return;
+               }
+               // Immediately update the most recent touched rows, which hopefully covers what
+               // the user sees on the watchlist page before pressing "mark all pages visited"....
+               $dbw->update(
+                       'watchlist',
+                       [ 'wl_notificationtimestamp' => null ],
+                       [ 'wl_user' => $id, 'wl_notificationtimestamp' => $asOfTimes ],
+                       __METHOD__
+               );
+               // ...and finish the older ones in a post-send update with lag checks...
+               DeferredUpdates::addUpdate( new AutoCommitUpdate(
+                       $dbw,
+                       __METHOD__,
+                       function () use ( $dbw, $id ) {
+                               global $wgUpdateRowsPerQuery;
+
+                               $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
+                               $ticket = $lbFactory->getEmptyTransactionTicket( __METHOD__ );
+                               $asOfTimes = array_unique( $dbw->selectFieldValues(
+                                       'watchlist',
+                                       'wl_notificationtimestamp',
+                                       [ 'wl_user' => $id, 'wl_notificationtimestamp IS NOT NULL' ],
+                                       __METHOD__
+                               ) );
+                               foreach ( array_chunk( $asOfTimes, $wgUpdateRowsPerQuery ) as $asOfTimeBatch ) {
+                                       $dbw->update(
+                                               'watchlist',
+                                               [ 'wl_notificationtimestamp' => null ],
+                                               [ 'wl_user' => $id, 'wl_notificationtimestamp' => $asOfTimeBatch ],
+                                               __METHOD__
+                                       );
+                                       $lbFactory->commitAndWaitForReplication( __METHOD__, $ticket );
+                               }
+                       }
+               ) );
+               // We also need to clear here the "you have new message" notification for the own
+               // user_talk page; it's cleared one page view later in WikiPage::doViewUpdates().
        }
 
        /**