X-Git-Url: https://git.heureux-cyclage.org/?a=blobdiff_plain;f=includes%2FRevision.php;h=6acc528f76bcde938da16cabfb024d5df1cab6cc;hb=33cb9b0d30aff88300d2708e0b820f9db9d2a4dc;hp=ef0f03df8f357d4aa51bd9923998e8998298673d;hpb=5316e7d70061457420dc27434d9e7230bc7f031d;p=lhc%2Fweb%2Fwiklou.git

diff --git a/includes/Revision.php b/includes/Revision.php
index ef0f03df8f..6acc528f76 100644
--- a/includes/Revision.php
+++ b/includes/Revision.php
@@ -1577,19 +1577,20 @@ 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 +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 ) {