Merge "Set default wgMultiContentRevisionSchemaMigrationStage to write-both"

[lhc/web/wiklou.git] / includes / libs / objectcache / BagOStuff.php

diff --git a/includes/libs/objectcache/BagOStuff.php b/includes/libs/objectcache/BagOStuff.php
index ca0e721..782f4c6 100644 (file)
--- a/includes/libs/objectcache/BagOStuff.php
+++ b/includes/libs/objectcache/BagOStuff.php
@@ -185,7 +185,7 @@ abstract class BagOStuff implements IExpiringStore, LoggerAwareInterface {
         *
         * @param string $key
         * @param int $flags Bitfield of BagOStuff::READ_* constants [optional]
-        * @param int $oldFlags [unused]
+        * @param int|null $oldFlags [unused]
         * @return mixed Returns false on failure and if the item does not exist
         */
        public function get( $key, $flags = 0, $oldFlags = null ) {
@@ -343,7 +343,21 @@ abstract class BagOStuff implements IExpiringStore, LoggerAwareInterface {
         * @throws Exception
         */
        protected function cas( $casToken, $key, $value, $exptime = 0 ) {
-               throw new Exception( "CAS is not implemented in " . __CLASS__ );
+               if ( !$this->lock( $key, 0 ) ) {
+                       return false; // non-blocking
+               }
+
+               $curCasToken = null; // passed by reference
+               $this->getWithToken( $key, $curCasToken, self::READ_LATEST );
+               if ( $casToken === $curCasToken ) {
+                       $success = $this->set( $key, $value, $exptime );
+               } else {
+                       $success = false; // mismatched or failed
+               }
+
+               $this->unlock( $key );
+
+               return $success;
        }
 
        /**
@@ -357,7 +371,13 @@ abstract class BagOStuff implements IExpiringStore, LoggerAwareInterface {
         * @return bool Success
         */
        protected function mergeViaLock( $key, $callback, $exptime = 0, $attempts = 10, $flags = 0 ) {
-               if ( !$this->lock( $key, 6 ) ) {
+               if ( $attempts <= 1 ) {
+                       $timeout = 0; // clearly intended to be "non-blocking"
+               } else {
+                       $timeout = 3;
+               }
+
+               if ( !$this->lock( $key, $timeout ) ) {
                        return false;
                }
 
@@ -760,7 +780,7 @@ abstract class BagOStuff implements IExpiringStore, LoggerAwareInterface {
         *
         * @since 1.27
         * @param string $class Key class
-        * @param string $component [optional] Key component (starting with a key collection name)
+        * @param string|null $component [optional] Key component (starting with a key collection name)
         * @return string Colon-delimited list of $keyspace followed by escaped components of $args
         */
        public function makeGlobalKey( $class, $component = null ) {
@@ -772,7 +792,7 @@ abstract class BagOStuff implements IExpiringStore, LoggerAwareInterface {
         *
         * @since 1.27
         * @param string $class Key class
-        * @param string $component [optional] Key component (starting with a key collection name)
+        * @param string|null $component [optional] Key component (starting with a key collection name)
         * @return string Colon-delimited list of $keyspace followed by escaped components of $args
         */
        public function makeKey( $class, $component = null ) {