question: public void updateStats ( int fIdx , long count ) { synchronized ( pq ) { frmtCount [ fIdx ] += count ; Stats tmp = new Stats ( fIdx , frmtCount [ fIdx ] ) ; pq . remove ( tmp ) ; pq . offer ( tmp ) ; } if ( LOG . isTraceEnabled ( ) ) { LOG . trace ( "update forest " + fIdx ) ; } }
target:  add count to forest with index fIdx, which may not be the forest with minimum frmtCount. Used by fragment count rollback.