source: fedd/abac-src/ttg/credential/DiscoveryService.java @ bc24428

package com.nailabs.abac.credential;

import java.io.*;
import java.util.*;
import edu.stanford.peer.rbtm.credential.*;
import edu.stanford.peer.rbtm.engine.*;
import edu.stanford.peer.rbtm.util.*;
import edu.stanford.rt.parser.*;
import edu.stanford.rt.credential.*;
 
/** 
 * A service object which encapsulates the functions of a CredentialManager
 * that are necessary for remote and local discovery.
 */
public class DiscoveryService {
    /** The graphine which performs the actual searches */
    protected RtmlEngine engine;
    /** An RTML parser which can be shared for all discovery services */
    protected static RTParser parser = null;
    /** AN RTML context which can be shared across all discovery services */
    protected static RTContext context = null;

    static {
        try {
            parser = new RTParser();
            context = new RTContext(parser);
        } catch(Exception ex) {
            ex.printStackTrace();
        }
    }

    /** Default constructor */
    public DiscoveryService(String storeFile) {
        try {
            parser = new RTParser();
            context = new RTContext(parser);
            CredentialStore store = new CredentialStore(parser);
            parser.parseCredentialStore
                (new FileInputStream(new File(storeFile)), context, store);
            this.engine = new RtmlEngine(store);
        } catch (Exception ex) {
            //ex.printStackTrace();
        }
    }

    /** 
     * For each result in the map, match the RTML for the domain of the 
     * rtml credential.
     */
    protected String[] soapify(ResultEvidenceMap map) {
        Object results[] = map.resultSet().toArray();
        int max = results.length;
        String[] evidence = new String[max];
        for(int i = 0; i < max; i++) {
            Object obj = map.getResultEvidence(results[i]);
            if(obj instanceof RtmlCredential) {
                RtmlCredential cred = (RtmlCredential)obj;
                evidence[i] = cred.toXML();
            } else {
                evidence[i] = results[i] + " -" + obj.toString();
            }
        }
        return evidence;
    }

    /**
     * Convert a collection of <CODE>RTMLCredential</CODE> instances into a 
     * set of their <CODE>CredentialDomain</CODE> instances.
     */
    protected String[] soapify(Collection c) {
        //String[] credentials = new String[c.size()];
        HashSet credentials = new HashSet(c.size());
        Iterator results = c.iterator();
        String output[];
        int i = 0;
        
        while(results.hasNext()) {
            Object obj = results.next();
            if(obj instanceof RtmlCredential) {
                RtmlCredential cred = (RtmlCredential)obj;
                //credentials[i++] = cred.toXML();
                credentials.add(cred.toXML());
            } else {
                //credentials[i++] = obj.toString();
                credentials.add(obj.toString());
            }
        }
        output = new String[credentials.size()];
        results = credentials.iterator(); 
        for(i = 0; results.hasNext(); i++) {
            output[i] = results.next().toString();
        }
        return output;
    }

    /**
     * For a specified entity name, return all <code>CredentialDomain</code>
     * instances which were issued by the entity.
     */
    public String[] getCredentialsIssuedBy(String entityName) {
        Entity e = new RtmlEntity(entityName);
        return soapify(engine.getCredentialsIssuedBy(e));
        //return soapify(engine.backwardSearch(e));
    }

    /**
     * For the specified role, return all <code>CredentialDomain</code> 
     * instances which define the specified role (entity.role).
     */
    public String[] findCredentialsDefiningRole(String entity, String role) {
        Entity e = new RtmlEntity(entity);
        edu.stanford.peer.rbtm.credential.Role r = 
            new edu.stanford.peer.rbtm.credential.Role(e, role);
        Iterator results = engine.findCredentialsDefiningRole(r);
        HashSet evidence = new HashSet();
        StringBuffer buff = new StringBuffer("DefiningRole(");
        buff.append(entity).append(".").append(role).append(") = ");
        while(results.hasNext()) {
            Object result = results.next();
            //System.out.println("def result = " + result);
            buff.append(result.toString()).append(" ");
            evidence.add(result);
        }
        System.out.println(buff.toString());
        return soapify(evidence);
    }

    /**
     * For a given entity expression, find the <code>CredentialDomain</code>
     * instances which define credentials that have the entity expression as 
     * a subject.
     */
    public String[] findCredentialsBySubject(String expr) {
        EntityExpression ee = null;
        try {
            ee = StaticCredential.getEntityExpression(expr);
            ee = RtmlExpression.convert(ee);
        } catch (Exception cpe) {
            cpe.printStackTrace();
        }
        Iterator results = engine.findCredentialsBySubject(ee);
        HashSet evidence = new HashSet();
        StringBuffer buff = new StringBuffer("BySubject(");
        buff.append(expr).append(") = ");
        while(results.hasNext()) {
            Object result = results.next();
            //System.out.println("subj result = " + result);
            buff.append(result).append(" ");
            if(!evidence.contains(result)) {
                evidence.add(result);
            }
        }
        System.out.println(buff.toString());
        return soapify(evidence);
    }

    /**
     * Add a new <code>CredentialDomain</code> to the underlying 
     * <code>CredentialStore</code>.
     * @param xml an xml block which defined a <code>CredentialDomain</code>
     */
    public void addCredentialDomain(String xml) {
        try {
            InputStream in = new ByteArrayInputStream(xml.getBytes());
            CredentialDomain domain = 
                parser.parseCredentialDomain(in, context);
            synchronized(engine) {
                engine.addDomain(domain);
            }
        } catch(Exception ex) {
            ex.printStackTrace();
        }
    }

}