Class OperatorSubPlan

src/org/apache/pig/newplan/OperatorSubPlan.java:38–206

Class to represent a view of a plan. The view contains a subset of the plan. All the operators returned from the view are the same objects to the operators in its base plan. It is used to represent match results.

 *
 */
public class OperatorSubPlan implements OperatorPlan {

    private OperatorPlan basePlan;
    private List<Operator> roots;
    private List<Operator> leaves;
    private Set<Operator> operators;

    public OperatorSubPlan(OperatorPlan base) {
        basePlan = base;
        roots = new ArrayList<Operator>();
        leaves = new ArrayList<Operator>();
        operators = new HashSet<Operator>();
    }                
    
    public OperatorPlan getBasePlan() {
        return basePlan;
    }
    
    @Override
    public void add(Operator op) {
        operators.add(op);
        leaves.clear();
        roots.clear();
    }

    @Override
    public void connect(Operator from, int fromPos, Operator to, int toPos) {
        throw new UnsupportedOperationException("connect() can not be called on OperatorSubPlan");
    }

    @Override
    public void connect(Operator from, Operator to) {
        throw new UnsupportedOperationException("connect() can not be called on OperatorSubPlan");
    }

    @Override
    public Pair<Integer, Integer> disconnect(Operator from, Operator to) throws FrontendException {
        throw new UnsupportedOperationException("disconnect() can not be called on OperatorSubPlan");
    }

    @Override
    public List<Operator> getSinks() {
        if (leaves.size() == 0 && operators.size() > 0) {
            for (Operator op : operators) {       
                if (getSuccessors(op) == null) {
                    leaves.add(op);
                }
            }
        }
        return leaves;
    }

    @Override
    public Iterator<Operator> getOperators() {
        return operators.iterator();
    }

    @Override