source: fedd/abac-src/rbtm/engine/PartialSolutionMap.java @ 23dec62

package edu.stanford.peer.rbtm.engine;

import java.util.*;
import edu.stanford.peer.rbtm.credential.*;
/**
 * A map which keeps track of how many partial solutions reach a proof node,
 * using a decrementing counter, which is initialized to k for each 
 * intersection.
 */
public class PartialSolutionMap
{
         /** table of decrementing counters, one per intersection */
         HashMap counters = new HashMap();

         /** get the count of outstanding partial solutions */
         public int getPartialSolutionCount(Intersection inter) {
                  return ((Integer)counters.get(inter)).intValue();
         }
         
         /**
          * decrement the counter by 1 for the specified intersect, creating a 
          * new counter, if necessary 
          */
         public boolean addPartialSolution(Intersection inter,EntityExpression expr)
         {
                  int partialSolutionCount = -1;
                  try {
                                partialSolutionCount = getPartialSolutionCount(inter);
                  } catch(NullPointerException nullEx) {
                                partialSolutionCount = inter.getPartsCount();
                  } catch(Exception ex) {
                                ex.printStackTrace();
                  }
                  counters.put(inter, new Integer(--partialSolutionCount));
                  return (partialSolutionCount == 0)? true: false;
         }
}