Late Night VRML 2.0 with Java CD-ROM/code.zip/Ch19/registry/RegistryServer.java

Java Source | 1997-01-27 | 6.3 KB | 332 lines

// Simple Multiuser Server
// (c) Copyright Justin Couch   [e-mail]
// The Virtual Light Company 1996
//
// From Chapter 20: Late Night VRML 2.0 and java
//
// This is the Registry  class. Details about each avatar are kept here.
// Avatar entity IDs start from 1

package registry;

import java.io.*;
import java.util.*;

public class RegistryServer extends Thread
{
    private static int next_entity_id = 0;

    private Vector entity_list;
    private Hashtable    name_list;
    private Hashtable    user_identities;

    public RegistryServer(ThreadGroup tg)
    {
        super(tg, "Registry Server Thread");

        setPriority(7);

        System.out.println("Starting Registry Server");

        entity_list = new Vector(10,2);
        name_list = new Hashtable(100, 0.8f);
        user_identities = new Hashtable(20, 0.8f);
    }

    // allocate a new entity.
    // return values:
    //    -1 if cname already in use
    //    -2 if user not identified
    //     > 0 sucessful, the new id number
    // The caller must make sure that the ident is legally valid to add
    // a new entity.
    public synchronized int allocate(String cname, String ident)
    {
        Entity entity;

        // first check the name list for the given entity;
        if(name_list.get(cname) != null)
            return(-1);

        next_entity_id++;

        entity = new Entity(cname, next_entity_id, ident);

        // need to add an entity class to the Vector
        entity_list.addElement(entity);
        name_list.put(cname, entity);

        return(next_entity_id);
    }

    public synchronized boolean set_URL(int entid, String ident,  String url)
    {
        int    i;
        Entity    e;

        for(i = 0; i < entity_list.size(); i++)
        {
            e = (Entity)entity_list.elementAt(i);

            // currently no checking on the ownership of the entity.
            if(e.ID == entid)
            {
                if(!e.get_owner().equals(ident))
                    return false;

                e.set_URL(url);
                break;
            }
        }

        return true;
    }

    public synchronized boolean set_nickname(int entid, String ident, String new_name)
    {
        int    i;
        Entity    e;

        for(i = 0; i < entity_list.size(); i++)
        {
            e = (Entity)entity_list.elementAt(i);

            // currently no checking on the ownership of the entity.
            if(e.ID == entid)
            {
                if(!e.get_owner().equals(ident))
                    return false;

                e.set_nickname(new_name);
                break;
            }
        }

        return true;
    }

    public synchronized boolean chown(int entid, String old_owner, String new_owner)
    {
        int    i;
        Entity    e;

        for(i = 0; i < entity_list.size(); i++)
        {
            e = (Entity)entity_list.elementAt(i);

            // currently no checking on the ownership of the entity.
            if(e.ID == entid)
            {
                if(!e.get_owner().equals(old_owner))
                    return false;

                e.set_owner(new_owner);
                break;
            }
        }

        return true;
    }

    public synchronized boolean set_persistent(int entid, String ident, boolean persist)
    {
        int    i;
        Entity    e;

        for(i = 0; i < entity_list.size(); i++)
        {
            e = (Entity)entity_list.elementAt(i);

            // currently no checking on the ownership of the entity.
            if(e.ID == entid)
            {
                if(!e.get_owner().equals(ident))
                    return false;

                e.set_persistent(persist);
                break;
            }
        }

        return true;
    }

    public synchronized boolean set_avatar(int entid, String ident, boolean avatar)
    {
        int    i;
        Entity    e;

        for(i = 0; i < entity_list.size(); i++)
        {
            e = (Entity)entity_list.elementAt(i);

            // currently no checking on the ownership of the entity.
            if(e.ID == entid)
            {
                if(!e.get_owner().equals(ident))
                    return false;

                e.set_avatar(avatar);
                break;
            }
        }

        return true;
    }

    public synchronized boolean set_info(int entid, String ident, String[] info)
    {
        int    i;
        Entity    e;

        for(i = 0; i < entity_list.size(); i++)
        {
            e = (Entity)entity_list.elementAt(i);

            // currently no checking on the ownership of the entity.
            if(e.ID == entid)
            {
                if(!e.get_owner().equals(ident))
                    return false;

                e.set_publicInfo(info);
                break;
            }
        }

        return true;
    }

    public synchronized void printInfo(int entid, PrintStream out)
    {
        int    i, j;
        Entity    e;
        String[] info;

        for(i = 0; i < entity_list.size(); i++)
        {
            e = (Entity)entity_list.elementAt(i);

            // currently no checking on the ownership of the entity.
            if(e.ID == entid)
            {
                info = e.get_publicInfo();

                if(info == null)
                    break;

                for(j = 0; j < info.length; j++)
                    out.println(info[j]);

                break;
            }
        }
    }

    public synchronized void printEntityInfo(int entid, PrintStream out, String nick)
    {
        int    i;
        Entity    e;

        for(i = 0; i < entity_list.size(); i++)
        {
            e = (Entity)entity_list.elementAt(i);

            // currently no checking on the ownership of the entity.
            if(e.ID == entid)
            {
                out.print(e.get_cname() + " " + e.get_URL() + " ");
                out.print(e.get_owner() + " " + e.isAvatar() + " ");
                out.print(e.isPersistent() + " ");
                out.println(e.get_registrationTime());
                out.println(e.get_nickname());
                // this is incorrect because it should be a list
                // of the SSRC values. not just a single flag.
                out.println(e.get_flags());
                break;
            }
        }

    }

    public synchronized void printList(PrintStream out)
    {
        int    i;
        for(i = 0; i < entity_list.size(); i++)
            out.println(((Entity)entity_list.elementAt(i)).ID);
    }

    public synchronized boolean delete(int entid, String ident)
    {
        int    i;
        Entity    e;

        for(i = 0; i < entity_list.size(); i++)
        {
            e = (Entity)entity_list.elementAt(i);

            // currently no checking on the ownership of the entity.
            if(e.ID == entid)
            {
                if(!e.get_owner().equals(ident))
                    return false;

                entity_list.removeElementAt(i);
                name_list.remove(e.get_cname());
                break;
            }
        }

        return true;
    }

    public boolean verifyIdent(String uname, String passwd)
    {
        String curr_passwd = (String)user_identities.get(uname);

        if(curr_passwd == null)
        {
            user_identities.put(uname, passwd);
            return true;
        }

        return(curr_passwd.equals(passwd));
    }

    public synchronized boolean isOwner(int entid, String ident)
    {
        int    i;
        Entity    e;

        for(i = 0; i < entity_list.size(); i++)
        {
            e = (Entity)entity_list.elementAt(i);

            if(e.ID == entid)
            {
                if(e.get_owner().equals(ident))
                    return true;
                break;
            }
        }

        return false;
    }

    public synchronized void listNew(int time, PrintStream out)
    {
        int    i;
        Entity    e;
        long    earliest_time = System.currentTimeMillis() - time;

        for(i = 0; i < entity_list.size(); i++)
        {
            e = (Entity)entity_list.elementAt(i);

            if(e.get_lastUpdateTime() > earliest_time)
                out.println(e.ID);
        }
    }
}