synchronized int lookup(final Object tx,final boolean insert){
  if (tx == null) {
    throw new IllegalArgumentException("transaction object is null");
  }
  Integer index=(Integer)mapping.get(tx);
  if (index == null) {
    if (insert) {
      final int capacity=capacity();
      final int nvertices=mapping.size();
      if (nvertices == capacity) {
        throw new MultiprogrammingCapacityExceededException("capacity=" + capacity + ", nvertices="+ nvertices);
      }
      index=(Integer)indices.remove(0);
      mapping.put(tx,index);
      final int ndx=index.intValue();
      if (transactions[ndx] != null) {
        throw new AssertionError();
      }
      transactions[ndx]=tx;
    }
 else {
      return -1;
    }
  }
  return index.intValue();
}

synchronized int lookup ( final Object tx , final boolean insert ) { if ( tx == null ) { throw new IllegalArgumentException ( "transaction object is null" ) ; } Integer index = ( Integer ) mapping . get ( tx ) ; if ( index == null ) { if ( insert ) { final int capacity = capacity ( ) ; final int nvertices = mapping . size ( ) ; if ( nvertices == capacity ) { throw new MultiprogrammingCapacityExceededException ( "capacity=" + capacity + ", nvertices=" + nvertices ) ; } index = ( Integer ) indices . remove ( 0 ) ; mapping . put ( tx , index ) ; final int ndx = index . intValue ( ) ; if ( transactions [ ndx ] != null ) { throw new AssertionError ( ) ; } transactions [ ndx ] = tx ; } else { return - 1 ; } } return index . intValue ( ) ; }
lookup index assigned to transaction object .
