source: fedd/abac-src/ttg/trust/TTGNodeSet.java @ ab37086

package com.nailabs.abac.trust;

import edu.stanford.peer.rbtm.credential.*;
import java.util.*;

/**
 * Place holder for sets of nodes. An internal index keeps track of nodes
 * as new ones are added to the set. Future versions may implement a sorting 
 * algorithm for nodes. 
 */
public class TTGNodeSet extends HashMap {
    
    /** index of nodes that have been enqueued for processing */
    protected LinkedList index = new LinkedList();

    /** add a single trust target graph node to the set */
    public boolean add(TTGNode node) {
        boolean isNew = containsValue(node);

        if(node == null) {
            System.out.println("Attempting to add null node!!");
            return false;
        }
        if(isNew) {
            System.out.println("Duplicate node in set. " + node.getGoal());
            index.add(node);
        } 
        put(node.getGoal(), node);
        return isNew;
    }

    /** adds a set of nodes to the set */
    public boolean addAll(TTGNodeSet set) {
        boolean result = false;
        Iterator i = set.values().iterator();
        while(i.hasNext()) {
            TTGNode node = (TTGNode)i.next();
            result = (result || add(node));
        }
        return result;
    }

    public Object getFirst() {
        return index.getFirst();
    }

    public Object getLast() {
        return index.getLast();
    }
}