Merge "MovePage: Fix old, old bug with moving over redirects"

[lhc/web/wiklou.git] / includes / db / loadbalancer / LBFactory.php

diff --git a/includes/db/loadbalancer/LBFactory.php b/includes/db/loadbalancer/LBFactory.php
index 4078a39..efc6148 100644 (file)
--- a/includes/db/loadbalancer/LBFactory.php
+++ b/includes/db/loadbalancer/LBFactory.php
@@ -42,6 +42,8 @@ abstract class LBFactory implements DestructibleService {
        /** @var WANObjectCache */
        protected $wanCache;
 
+       /** @var mixed */
+       protected $ticket;
        /** @var string|bool Reason all LBs are read-only or false if not */
        protected $readOnlyReason = false;
 
@@ -72,6 +74,7 @@ abstract class LBFactory implements DestructibleService {
                        $this->wanCache = WANObjectCache::newEmpty();
                }
                $this->trxLogger = LoggerFactory::getInstance( 'DBTransaction' );
+               $this->ticket = mt_rand();
        }
 
        /**
@@ -404,6 +407,44 @@ abstract class LBFactory implements DestructibleService {
                }
        }
 
+       /**
+        * Get a token asserting that no transaction writes are active
+        *
+        * @param string $fname Caller name (e.g. __METHOD__)
+        * @return mixed A value to pass to commitAndWaitForReplication()
+        * @since 1.28
+        */
+       public function getEmptyTransactionTicket( $fname ) {
+               if ( $this->hasMasterChanges() ) {
+                       $this->trxLogger->error( __METHOD__ . ": $fname does not have outer scope." );
+                       return null;
+               }
+
+               return $this->ticket;
+       }
+
+       /**
+        * Convenience method for safely running commitMasterChanges()/waitForReplication()
+        *
+        * This will commit and wait unless $ticket indicates it is unsafe to do so
+        *
+        * @param string $fname Caller name (e.g. __METHOD__)
+        * @param mixed $ticket Result of getOuterTransactionScopeTicket()
+        * @param array $opts Options to waitForReplication()
+        * @throws DBReplicationWaitError
+        * @since 1.28
+        */
+       public function commitAndWaitForReplication( $fname, $ticket, array $opts = [] ) {
+               if ( $ticket !== $this->ticket ) {
+                       $logger = LoggerFactory::getInstance( 'DBPerformance' );
+                       $logger->error( __METHOD__ . ": cannot commit; $fname does not have outer scope." );
+                       return;
+               }
+
+               $this->commitMasterChanges( $fname );
+               $this->waitForReplication( $opts );
+       }
+
        /**
         * Disable the ChronologyProtector for all load balancers
         *