Merge "Convert LanguageConverter to using getLocalServerObjectCache()"

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

diff --git a/includes/Revision.php b/includes/Revision.php
index ef0f03d..208652f 100644 (file)
--- a/includes/Revision.php
+++ b/includes/Revision.php
@@ -1046,11 +1046,10 @@ class Revision implements IDBAccessObject {
         *   to the $audience parameter
         *
         * @deprecated since 1.21, use getContent() instead
-        * @todo Replace usage in core
         * @return string
         */
        public function getText( $audience = self::FOR_PUBLIC, User $user = null ) {
-               ContentHandler::deprecated( __METHOD__, '1.21' );
+               wfDeprecated( __METHOD__, '1.21' );
 
                $content = $this->getContent( $audience, $user );
                return ContentHandler::getContentText( $content ); # returns the raw content text, if applicable
@@ -1396,6 +1395,11 @@ class Revision implements IDBAccessObject {
        public function insertOn( $dbw ) {
                global $wgDefaultExternalStore, $wgContentHandlerUseDB;
 
+               // We're inserting a new revision, so we have to use master anyway.
+               // If it's a null revision, it may have references to rows that
+               // are not in the replica yet (the text row).
+               $this->mQueryFlags |= self::READ_LATEST;
+
                // Not allowed to have rev_page equal to 0, false, etc.
                if ( !$this->mPage ) {
                        $title = $this->getTitle();
@@ -1577,19 +1581,20 @@ class Revision implements IDBAccessObject {
         * @return string|bool The revision's text, or false on failure
         */
        private function loadText() {
-               // Caching may be beneficial for massive use of external storage
                global $wgRevisionCacheExpiry;
 
-               if ( !$wgRevisionCacheExpiry ) {
-                       return $this->fetchText();
-               }
-
                $cache = ObjectCache::getMainWANInstance();
+               if ( $cache->getQoS( $cache::ATTR_EMULATION ) <= $cache::QOS_EMULATION_SQL ) {
+                       // Do not cache RDBMs blobs in...the RDBMs store
+                       $ttl = $cache::TTL_UNCACHEABLE;
+               } else {
+                       $ttl = $wgRevisionCacheExpiry ?: $cache::TTL_UNCACHEABLE;
+               }
 
                // No negative caching; negative hits on text rows may be due to corrupted replica DBs
                return $cache->getWithSetCallback(
-                       $key = $cache->makeKey( 'revisiontext', 'textid', $this->getTextId() ),
-                       $wgRevisionCacheExpiry,
+                       $cache->makeKey( 'revisiontext', 'textid', $this->getTextId() ),
+                       $ttl,
                        function () {
                                return $this->fetchText();
                        },
@@ -1608,25 +1613,38 @@ 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 ) {