$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 ) {