Merge "Make $wgRevisionCacheExpiry default to one week"

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

diff --git a/includes/Revision.php b/includes/Revision.php
index af45acc..6acc528 100644 (file)
--- a/includes/Revision.php
+++ b/includes/Revision.php
@@ -1609,25 +1609,38 @@ class Revision implements IDBAccessObject {
                        $row = null;
                }
 
+               // Callers doing updates will pass in READ_LATEST as usual. Since the text/blob tables
+               // do not normally get rows changed around, set READ_LATEST_IMMUTABLE in those cases.
+               $flags = $this->mQueryFlags;
+               $flags |= DBAccessObjectUtils::hasFlags( $flags, self::READ_LATEST )
+                       ? self::READ_LATEST_IMMUTABLE
+                       : 0;
+
+               list( $index, $options, $fallbackIndex, $fallbackOptions ) =
+                       DBAccessObjectUtils::getDBOptions( $flags );
+
                if ( !$row ) {
                        // Text data is immutable; check replica DBs first.
-                       $dbr = wfGetDB( DB_REPLICA );
-                       $row = $dbr->selectRow( 'text',
+                       $row = wfGetDB( $index )->selectRow(
+                               'text',
                                [ 'old_text', 'old_flags' ],
                                [ 'old_id' => $textId ],
-                               __METHOD__ );
+                               __METHOD__,
+                               $options
+                       );
                }
 
-               // Fallback to the master in case of replica DB lag. Also use FOR UPDATE if it was
-               // used to fetch this revision to avoid missing the row due to REPEATABLE-READ.
-               $forUpdate = ( $this->mQueryFlags & self::READ_LOCKING == self::READ_LOCKING );
-               if ( !$row && ( $forUpdate || wfGetLB()->getServerCount() > 1 ) ) {
-                       $dbw = wfGetDB( DB_MASTER );
-                       $row = $dbw->selectRow( 'text',
+               // Fallback to DB_MASTER in some cases if the row was not found
+               if ( !$row && $fallbackIndex !== null ) {
+                       // Use FOR UPDATE if it was used to fetch this revision. This avoids missing the row
+                       // due to REPEATABLE-READ. Also fallback to the master if READ_LATEST is provided.
+                       $row = wfGetDB( $fallbackIndex )->selectRow(
+                               'text',
                                [ 'old_text', 'old_flags' ],
                                [ 'old_id' => $textId ],
                                __METHOD__,
-                               $forUpdate ? [ 'FOR UPDATE' ] : [] );
+                               $fallbackOptions
+                       );
                }
 
                if ( !$row ) {