+ protected function doDBUpdates() {
+ $db = wfGetDB( DB_MASTER );
+ if ( !$db->tableExists( 'revision' ) ) {
+ $this->error( "revision table does not exist" );
+ return false;
+ }
+ $this->output( "Populating rev_parent_id column\n" );
+ $start = $db->selectField( 'revision', 'MIN(rev_id)', false, __FUNCTION__ );
+ $end = $db->selectField( 'revision', 'MAX(rev_id)', false, __FUNCTION__ );
+ if ( is_null( $start ) || is_null( $end ) ) {
+ $this->output( "...revision table seems to be empty, nothing to do.\n" );
+ return true;
+ }
+ # Do remaining chunk
+ $blockStart = intval( $start );
+ $blockEnd = intval( $start ) + $this->mBatchSize - 1;
+ $count = 0;
+ $changed = 0;
+ while ( $blockStart <= $end ) {
+ $this->output( "...doing rev_id from $blockStart to $blockEnd\n" );
+ $cond = "rev_id BETWEEN $blockStart AND $blockEnd";
+ $res = $db->select( 'revision',
+ array( 'rev_id', 'rev_page', 'rev_timestamp', 'rev_parent_id' ),
+ array( $cond, 'rev_parent_id' => null ), __METHOD__ );
+ # Go through and update rev_parent_id from these rows.
+ # Assume that the previous revision of the title was
+ # the original previous revision of the title when the
+ # edit was made...
+ foreach ( $res as $row ) {
+ # First, check rows with the same timestamp other than this one
+ # with a smaller rev ID. The highest ID "wins". This avoids loops
+ # as timestamp can only decrease and never loops with IDs (from parent to parent)
+ $previousID = $db->selectField( 'revision', 'rev_id',
+ array( 'rev_page' => $row->rev_page, 'rev_timestamp' => $row->rev_timestamp,
+ "rev_id < " . intval( $row->rev_id ) ),
+ __METHOD__,
+ array( 'ORDER BY' => 'rev_id DESC' ) );
+ # If there are none, check the the highest ID with a lower timestamp
+ if ( !$previousID ) {
+ # Get the highest older timestamp
+ $lastTimestamp = $db->selectField( 'revision', 'rev_timestamp',
+ array( 'rev_page' => $row->rev_page, "rev_timestamp < " . $db->addQuotes( $row->rev_timestamp ) ),
+ __METHOD__,
+ array( 'ORDER BY' => 'rev_timestamp DESC' ) );
+ # If there is one, let the highest rev ID win
+ if ( $lastTimestamp ) {
+ $previousID = $db->selectField( 'revision', 'rev_id',
+ array( 'rev_page' => $row->rev_page, 'rev_timestamp' => $lastTimestamp ),
+ __METHOD__,
+ array( 'ORDER BY' => 'rev_id DESC' ) );
+ }
+ }
+ $previousID = intval( $previousID );
+ if ( $previousID != $row->rev_parent_id )
+ $changed++;
+ # Update the row...
+ $db->update( 'revision',
+ array( 'rev_parent_id' => $previousID ),
+ array( 'rev_id' => $row->rev_id ),
+ __METHOD__ );
+ $count++;
+ }
+ $blockStart += $this->mBatchSize;
+ $blockEnd += $this->mBatchSize;
+ wfWaitForSlaves();
+ }
+ $this->output( "rev_parent_id population complete ... {$count} rows [{$changed} changed]\n" );
+ return true;
+ }