The Net: Ultimate Internet Guide/WWLCD1.ISO/pc/java/in4wjcxu/src/como/irc/comobjirc.java

Java Source | 1996-08-14 | 21.3 KB | 909 lines

/*
* @(#)ComObjIRC.java    1.0 96/03/03 Ulrich Gall & Jan Kautz
*
* Copyright (c) 1996 Ulrich Gall & Jan Kautz
* [e-mail]
* [e-mail]
* Hofmannstr. 48, D-91052 Erlangen, Germany, Fax: [phone]
*
*/

package como.irc;

import java.io.*;
import java.util.*;
import java.awt.*;
import java.applet.*;
import java.net.*;

import como.awt.*;
import como.commlet.*;
import como.util.*;
import como.sys.*;

public class ComObjIRC implements ComObj {
    private Hashtable involvedusers;
    private Hashtable allowedusers;
    private Hashtable usersleft;
    private Vector cache;
    private ServerIRC server;
    private Commlet commlet = null;
    private String commletname = "not_set.class";
    private String topic = "No topic set!";
    private Thread readthread;
    private CubbyHole cubbyhole;
    private IrcChan chan;
    private IrcSocket socket;
    private int myID;
    private int masterID;
    private boolean masterflag = false;
    protected boolean do_not_get_any_more_messages = false;
    private boolean i_am_not_allowed = false;

    /**
     * Start ComObjIRC. Establish Connection to given Channel.
     * Set up ReadThread for it.
     */
    ComObjIRC( ServerIRC s, IrcChan c, User ego, boolean iammaster ) throws IOException {
        chan = c;
        server = s;
        masterID = -1;
        masterflag = iammaster;

        involvedusers = new Hashtable();
        allowedusers  = new Hashtable();
        usersleft     = new Hashtable();
        cache         = new Vector();

        // create cubbyhole for answer messages
        cubbyhole = new CubbyHole();

        // open connection to ircd on the server
        // and join the channel chan.ircName()
        try {
            socket = new IrcSocket( server, chan );
        } catch( IOException e ) {
            // this means to me: leave
            throw new IOException();
        }

        topic = chan.topic;

        /* this here is really ugly, but what shall I do else? */
        ego.put( User.NICK, socket.nick );
        myID = calcHashCode( ego );
        ego.put( User.ID, new Integer(myID) );

        involvedusers.put( new Integer(myID), ego );

        if( iammaster ) masterID = myID;

        // start my ReadThread, which reads from the given socket
        readthread = new ReadThreadIRC( this, socket );
        readthread.start();
    }


    /**
     * set the Name of the commlet
     */
    synchronized public void setCommletName( String name ) {
        commletname = name;
    }

    /**
     * Tell the ComObj about his commlet. This is necessary this way
     * because the ComObj is instantiated before the commlet
     */
    synchronized public void setCommlet( Commlet c ) {
        commlet = c;
    }

    /**
     * return the Commlet
     */
    public Commlet getCommlet() {
        return commlet;
    }

    /**
     * returns the master ID.
     * -1 means it is still unknown.
     */
    synchronized public int getMasterID() {
        return masterID;
    }

    /**
     * returns my ID.
     * -1 means it is still unknown (I didn't login myself to this commlet/comobj).
     */
    public int getMyID() {
        return myID;
    }

    /**
     * return true if i am the master
     */
    synchronized public boolean iAmMaster() {
        return masterflag;
    }

    /**
     * set a new topic (in the irc-channel) and tell others
     * about it.
     */
    synchronized public void setNewTopic( String topic ) {
        this.topic = topic;
        socket.send( "TOPIC #"+chan.ircName()+" :"+topic, true );
        sendToAll( new Msg( Msg.NEW_TOPIC, topic ) );
    }

    /**
     * It will set the which-User-attributes to the newuser-attributes,
     * paying attention to those attributes, who may not be altered.
     */
    synchronized private void setUser( User which, User newuser ) {
        Enumeration e = newuser.keys();
        while( e.hasMoreElements() )
        {
            Object key;
            Object elem;
            Integer i;

            key = e.nextElement();
            elem = newuser.get( key );
            if( key instanceof Integer )
            {
                i = (Integer)key;

                // things that I don't want to be overwritten
                if( i.equals( User.NICK ) || i.equals( User.COMOUSER ) ||
                    i.equals( User.SOCKET ) || i.equals( User.ID ) ) continue;
            }

            which.put( key, elem );
        }
    }

    /**
     * Change some attributes of the local user.
     * Some can't be changed (NICK, SOCKET, ID,...).
     */
    synchronized public void setLocalUser( User user ) {
        setUser( getUser( getMyID() ), user );
        sendToAll( new Msg( Msg.NEW_USER_INFO, getUser( getMyID() ) ) );
    }

    /**
     * return the User-information of the user with id.
     */
    synchronized public User getUser( int id ) {
        // TODO: get more information about him!!!
        // ask himself, perhaps
        // no dont ask. he will tell us automatically

        User user = (User)involvedusers.get( new Integer( id ) );

        // now let's try to find him in userleft
        if( user == null ) {
            user = (User)usersleft.get( new Integer( id ) );
        }

        return user;
    }

    /**
     * return the Username of the user with id.
     */
    synchronized public String getUserName( int id ) {
        if( id == -1 ) {
            return "NoName";
        } else {
            User user = getUser( id );
            return (String)user.get( User.NAME );
        }
    }

    /**
     * return a Vector of all involved Users
     */
    synchronized public Vector getUsers() {
        Vector v = new Vector();
        Enumeration e = involvedusers.elements();
        User me;

        // I want to have me as the first in the list!

        me = getUser( getMyID() );
        if( me == null ) return v;

        v.addElement( me.clone() );

        while( e.hasMoreElements() ) {
            User u = (User)e.nextElement();

            if( me == u ) continue;    // I am already in there

            u = (User)u.clone();        // don't show him the real and only
            v.addElement( u );
        }

        return v;
    }

    /**
     * Send Msg to msg.to
     */
    synchronized public void sendTo( Msg msg ) {
        User user = getUser( msg.to );
        msg.from = getMyID();

/* Well this is a bad thing here:
   If I call it like this, the handleMsg()
    may call again sendTo() which may call again
    handleMsg()... Then the handleMsg() can never
    be synchronized!!!

        if( msg.to == getMyID() )
            commlet.handleMsg( msg );
        else
*/

        {
            if( user == null )
                Debug.msg( 45, "ComObjIRC.sendTo(): unknown user "+msg.to );
            else
                sendTo( user, msg );
        }
    }

    /**
     * Send Message to User user
     */
    synchronized private void sendTo( User user, Msg msg ) {
        msg.from = getMyID();
        socket.writePrivMsg( user, msg );
    }

    /**
     * Send Msg to all users of this session except myself.
     */
    synchronized public void sendToOthers( Msg msg ) {
        msg.from = getMyID();
        msg.to = 0;
        socket.writeMsg( msg );
    }

    /**
     * Send Msg to all users of this session including myself.
     */
    synchronized public void sendToAll( Msg msg ) {
        // to the others
        sendToOthers( msg );


        // to myself
        msg.to = msg.from = getMyID();
        sendTo( msg );

        // If you wonder why we are sending
        // even my own things to the IRC-Server:
        // We think it is necessary, that Messages
        // that are sent to everyone by e.g. two users
        // should arrive in the same order everywhere!
        // This can only be guaranteed, if we send
        // it back to the IRC-Server.
        // If you only have commlets, that don't insist
        // on this, you could use:
        // commlet.handleMsg( msg );
        // But then you have to make a Thread for it, because
        // it could block everything otherwise!!!
    }

    /**
     * Send Msg to group of users of this session.
     */
    synchronized public void sendToGroup( int to[], Msg msg ) {
        int len = to.length;

        for( int i = 0; i < len; i++ ) {
            msg.to = to[i];
            sendTo( msg );
        }
    }

    /**
     * ask msg.to msg. Then wait for a return-msg. The type
     * of the return msg must be -msg.type of the question!!
     */
    public synchronized Msg ask( Msg msg ) {
        sendTo( msg );

        // answer must be: -Msg.type !!!
        // else I will wait until doom's day!

        return (Msg)cubbyhole.get();
    }


    /**
     * kickUser kicks a User out of this channel!
     * It send him a KICK_USER message!
     */
    synchronized public void kickUser( int id, String reason ) {
        sendTo( new Msg( Msg.KICK_USER, getMyID(), id, reason ) );
    }

    /**
     * This method is invoked when a user left. It is called in every
     * ComObj belonging to this communication. In every comobj it WILL
     * choose the same User as master!
     * This is done by choosing the user with the lowest ID.
     */
    synchronized private void chooseNewMaster() {
        Enumeration e = involvedusers.elements();
        int lowest_id = -1; // ids in ComObjIRC are always positive

        while( e.hasMoreElements() ) {
            User u = (User)e.nextElement();
            int uid = ((Integer)u.get( User.ID )).intValue();

            if( lowest_id == -1 ) {
                lowest_id = uid;
            }
            else {
                if( uid < lowest_id )
                    lowest_id = uid;
            }
        }

        masterID = lowest_id;    // now he is the new master
        if( masterID == getMyID() ) {
            masterflag = true;
        }
    }


    /**
     * Here we can handle msg for the ComObj (or messages
     * important for the ComObj)
     */
    synchronized public Msg preHandleMsg( Msg msg ) {
        User user = null;

        switch( msg.type ) {
            Integer userid;
            int id;

            case Msg.INVITATION:
                // This message is for the server!
                server.handleMsg( msg );
                return null;

            case Msg.KICK_USER:
                String reason = (String)msg.arg;
                Panel msgpanel = new Panel();
                if( reason == null ) reason = " ";
                msgpanel.setLayout( new VertLayout( VertLayout.STRETCH ) );
                msgpanel.add( new Label( "Sorry, you've been kicked out of the Channel" ) );
                msgpanel.add( new Label( "by "+getUserName( msg.from )+"!" ) );
                msgpanel.add( new Label( "Reason: "+(String)msg.arg ) );

                new SmartFrame( msgpanel, "OK" );
                destroy();

                // tell thread to stop now (will also be stopped by
                // comobj.logout(), called in getCommlet().stop()
                return msg;

            case Msg.NOT_ALLOWED:
                new SmartFrame( "Sorry, you are not allowed to join! Please quit your Commlet!" );

                i_am_not_allowed = true;
                sendPartMessage();

                // I wanted to quit it automatically, but this
                // does not work, because the message NOT_ALLOWED
                // comes before everything is initialized!
                // So don't do this. -> Let the user quit manually.
                // destroy();

                // tell thread to stop now! This is at least one
                // thing i can do, get no more incoming messages!
                return msg;

            case Msg.LINE_DROPPED:
                // Tell the commlet, that it must quit now!

                new SmartFrame( "Sorry, line to server dropped!" );
                destroy();

                // Sorry this is a special case :-(
                // Thread must know, that he must stop
                return msg;

            case Msg.USER_LEFT:
                String nick = (String)msg.arg;
                Enumeration e = involvedusers.keys();
                Integer testid;

                userid = new Integer( -1 );

                // search the nick in the involveduser-List
                // and get his ID
                while( e.hasMoreElements() )
                {
                    testid = (Integer)e.nextElement();
                    user = (User)involvedusers.get( testid );
                    if( ((String)user.get( User.NICK )).compareTo( nick ) == 0 )
                    {
                        userid = testid;
                        break;
                    }
                }
                if( userid.intValue() == -1 )
                {
                    Debug.msg( 43, "ComObjIRC.preHandleMsg(USER_LEFT): Unknown User "+nick+" left" );
                    return null;
                }

                // allowedusers.remove() should not be necessary here
                // user should have been removed already (in addUser())
                allowedusers.remove( userid );
                involvedusers.remove( userid );

                usersleft.put( userid, user );

                // was the user who the master? yes??
                // then choose a new one. just take the user
                // with the lowest ID. then tell the commlet
                chooseNewMaster();
                commlet.handleMsg( new Msg( Msg.NEW_MASTER, getMasterID(), getMyID(), new Integer(getMasterID()) ) );

                // now tell the commlet, that a user left.
                // make sure, that if he/she calls getUsers() the leaving user
                // is not in that list! But if he/she calls getUser(userid)
                // he/she still gets information about him/her!
                commlet.handleMsg( new Msg( Msg.USER_LEFT, userid.intValue(), getMyID(), userid ) );

                // TODO: remove it here ?
                // or always remember 10 users, or ...
                // But it seems ok like this....
                // perhaps sometimes I should change this!
                usersleft.remove( userid );
                return null;

            case Msg.ADD_USER:
                User who = (User)msg.arg;

                if( (id = loginUser( who )) > 0 )
                    addUser( id );
                else {
                    // well if i am the master tell him to leave again!

                    if( iAmMaster() )
                        sendTo( who, new Msg( Msg.NOT_ALLOWED ) );
                }
                return null;

            case Msg.GET_USER_INFO:
                Msg retmsg;

                // oh, I'm still not here
                if( getMyID() == -1 ) {
                    cacheMsg( msg );
                    return null;
                }

                user = getUser( getMyID() );

                // construct answer message for that query
                retmsg = new Msg( Msg.NEW_USER_INFO, 0, msg.from, user );
                sendTo( retmsg );
                return null;

            case Msg.NEW_USER_INFO:
                User newuser = (User)msg.arg, olduser;
                userid = new Integer(msg.from);

                olduser = (User)involvedusers.get( userid );
                if( olduser != null ) {
                    // Attention here:
                    // give him the old user info
                    // he has to get the new via getUser()
                    msg.arg = olduser.clone();

                    // set the olduser correctly
                    setUser( olduser, newuser );

                    return msg;
                } else {
                    cacheMsg( msg );
                    return null;
                }

            case Msg.NEW_MASTER:
                Integer i = (Integer)msg.arg;

                if( (User)involvedusers.get( i ) == null ) {
                    cacheMsg( msg );
                    return null;
                }

                if( masterflag == true )
                    Debug.msg( 55, "ComObjIRC().preHandleMsg().NEW_MASTER: impossible message" );

                masterID = i.intValue();

                if( masterID == getMyID() ) masterflag = true;

                // well nice to know this, but the commlet also
                // wants to know it!
                return msg;

            case Msg.NEW_TOPIC:

                if( involvedusers.get( new Integer( msg.from ) ) == null ) {
                    cacheMsg( msg );
                    return null;
                }
                else {
                    topic = (String)msg.arg;
                    return msg;
                }

            case Msg.NO_DATA:
                return null;

            default:
                if( involvedusers.get( new Integer( msg.from ) ) == null )
                {
                    cacheMsg( msg );
                    return null;
                }

                if( msg.isAnswer() )  // It is a answer for something!!
                {
                    cubbyhole.put( msg );
                    return null;
                }

                return msg;
        }
    }

    /**
     * Here I can cache messages. This is usefull, if I get a message
     * from a user that I don't know yet.
     */
    synchronized private void cacheMsg( Msg msg ) {
        long mil = System.currentTimeMillis();    // current time in milliseconds since 1970
        Long millis = new Long( mil );

        Vector elem = new Vector();
        elem.addElement( millis );
        elem.addElement( msg );

        cache.addElement( elem );
    }

    /**
     * Search the cache if I have messages from the specified user,
     * if true, then deliver it (i.e. commlet.handleMsg())
     * else, keep the messages.
     * This is called, when a user is added.
     */
    synchronized private void handleCachedMsg( int id ) {
        Enumeration e = cache.elements();

        while( e.hasMoreElements() ) {
            Vector elem = (Vector)e.nextElement();
            Msg msg = (Msg)elem.elementAt( 1 );

            if( msg.from == id ) {
                // aaah, it's from her or him

                cache.removeElement( elem );

                // I have to ask for a new enumeration!!!
                // Removing an element causes the
                // Enumeration to stop an element earlier
                // than it should (look at java/util/Vector.java)
                e = cache.elements();

                if( preHandleMsg( msg ) != null )
                {
                    // ok it's a message for the commlet

                    // well i have to set the 'to' here, because it could
                    // be zero (equals to all)
                    msg.to = getMyID();
                    commlet.handleMsg( msg );
                }
            }
        }
    }

    /**
     * Search the cache if I have messages older than 60 seconds;
     * if true delete them.
     */
    synchronized protected void removeOldCachedMsg() {
        Enumeration e = cache.elements();

        while( e.hasMoreElements() ) {
            Vector elem = (Vector)e.nextElement();
            Long millis = (Long)elem.elementAt(0);

            if( millis.longValue() < (System.currentTimeMillis() - (60 * 10 * 1000)) ) {
                // aaah, it's too old

                Msg msg = (Msg)elem.elementAt( 1 );

                cache.removeElement( elem );
            }
        }
    }

    /**
     * Asks commlet if the User is admitted to enter.
     */
    synchronized public int loginUser( User user ) {

        // let's see if I was permitted to join the commlet
        // if not, don't add any users.
        if( i_am_not_allowed ) return -1;

        if( commlet.isUserAdmitted( user ) ) {
            int id = calcHashCode( user );

            allowedusers.put( new Integer(id), user );
            return id;
        }
        else
            return -1;
    }

    /**
     * Adds a user who has already logged in.
     * It tells this user, who i am and if i am the master
     */
    synchronized public void addUser( int userid ) {
        User user;

        if( (user = (User)allowedusers.get( new Integer(userid) )) != null )
        {
            user.put( User.ID, new Integer(userid) );
            involvedusers.put( new Integer(userid), user );
            allowedusers.remove( new Integer(userid) );
            commlet.handleMsg( new Msg( Msg.ADD_USER, new Integer( userid ) ) );

            // now handle the cached messages
            handleCachedMsg( userid );

            // now tell her/him who i am.
            sendTo( new Msg( Msg.NEW_USER_INFO, getMyID(), userid, getUser( getMyID() ) ) );

            // if i am master tell him/her
            // and tell her the topic of this channel
            if( iAmMaster() )
            {
                sendTo( new Msg( Msg.NEW_MASTER, getMyID(), userid, new Integer(getMyID()) ) );
                sendTo( new Msg( Msg.NEW_TOPIC, getMyID(), userid, topic ) );
            }
        }
        else
            Debug.msg( 98, "Not allowed user called ComObj.addUser()" );
        return;
    }

    /**
     * Add myself to this Commlet.
     * If i am master then set the topic
     */
    synchronized public void addMe( User ego ) {
        commlet.handleMsg( new Msg( Msg.ADD_USER, new Integer(myID) ) );

        if( iAmMaster() )
        {
            setNewTopic( topic );
        }
    }

    /**
     * Calc a HashCode out of a user. Avoids same hashcode for
     * different nick names.
     */
    synchronized private int calcHashCode( User user ) {
        String nick = (String)user.get( User.NICK );
        int id = nick.hashCode();

        if( id < 0 ) id = -id;

        // as long as the id is already used !
        while( involvedusers.containsKey( new Integer(id) ) ||
                    allowedusers.containsKey( new Integer(id) ) )
            id++;

        return id;
    }

    synchronized private void sendPartMessage() {
        try {
            socket.send( "PART #"+chan.ircName(), true );
        } catch( Exception e ) {
            Debug.msg( 75, "ComObjIRC.logout(): Couldn't send PART-Message anymore" );
        }
    }

    /**
     * This is called in order to quit the ComObj.
     * It also tells the server, that i quitted.
     */
    synchronized public void logout() {
        do_not_get_any_more_messages = true;

        sendPartMessage();

        try {
            socket.close();
        } catch( Exception e ) {
            // noone cares anymore here!
            Debug.msg( 75, "ComObjIRC.logout(): Couldn't close socket." );
        }

        // I have to stop the read-thread after I quitted the IRC.
        // The other way I had problems to close the socket.
        // Don't ask me why!

        if( readthread != null && Thread.currentThread() != readthread )
        {
            // stop the readthread. then it is not possible anymore
            // to get message!
            readthread.stop();
            readthread = null;

        }

        server.loggedout( this, chan );
    }

    /**
     * Destroy everything in here. I.e. also quit the commlet.
     * It will also call logout().
     */
    public void destroy() {
        commlet.stop();
        // stops the commlet. the commlet calls
        // ComObjIRC.logout() and that disconnects
    }

    /**
     * opens an URL to your DocumentHost
     */
    private URL getDataURL( String append ) throws MalformedURLException {
        Applet a = server.getApplet();
        URL url = new URL(a.getDocumentBase(),server.PATH_COMMLET+commletname+"/"+append );

        return url;
    }

    /**
     * Load a picture with the specified filename!
     * It will be loaded from the BaseDocument's http-server.
     */
    public Image loadImage( String filename ) {
        Applet a = server.getApplet();
        if( a == null ) return null;

        try {
            URL url = getDataURL( filename );
            return a.getImage( url );
        } catch( Exception e ) {
            return null;
        }
    }

    /**
     * Load an audioclip with the specified filename!
     */
    public AudioClip loadAudioClip( String filename ) {
        Applet a = server.getApplet();
        if( a == null ) return null;

        try {
            URL url = getDataURL( filename );
            return a.getAudioClip( url );
        } catch( Exception e ) {
            return null;
        }
    }

    /**
     * Open an input-stream to the specified file!
     */
    public InputStream openInputStream( String filename ) {
        Applet a = server.getApplet();
        if( a == null ) return null;

        try {
            URL url = getDataURL( filename );
            return url.openStream();
        } catch( Exception e ) {
            return null;
        }
    }

    public String toString() {
        return "ComObjIRC for #"+chan.ircName();
    }
}

class ReadThreadIRC extends Thread {
    ComObjIRC comobj;
    IrcSocket socket;

    ReadThreadIRC( ComObjIRC co, IrcSocket socket ) {
        comobj = co;
        this.socket = socket;
    }

    public void run() {
        Msg msg;

        // ah well. it can happen that I don't know yet what my commlet is
        // this means to me: wait for it.
        while( true ) {
            if( comobj.getCommlet() != null ) break;
            try {
                Thread.sleep( 100 );
            } catch( InterruptedException e ) { }
        }

        while( true )
        {
            msg = readMsg();

            if( msg == null )
                continue;  // already handled

            if( msg.type == Msg.LINE_DROPPED || msg.type == Msg.NOT_ALLOWED ||
                 msg.type == Msg.KICK_USER ) {
                // Sorry, this is a special case :(
                // We must stop this thread now!
                break;
            }

            msg.to = comobj.getMyID();
            comobj.getCommlet().handleMsg(msg);
        }
    }

    /**
     * read a Msg from my socket. Handle Messages for the ComObj,
     * before the Commlet gets it.
     */
    Msg readMsg() {
        Msg msg;

        msg = socket.readMsg();

        // that is when we are logging out!
        // tell the read thread to stop.
        if( comobj.do_not_get_any_more_messages == true )
            return new Msg( Msg.LINE_DROPPED );

        // here let's delete old cached messages!
        // it's not important where/when I do it, but it
        // has to be done
        comobj.removeOldCachedMsg();

        // Here we handle private Message, not
        // to be used by the commlet
        // returns null if msg was handled
        // else: returns the orginal msg
        return comobj.preHandleMsg( msg );
    }
}