/* netjscene.java - scene handling of the VRML net java server Copyright (C) 2002 Peter Graf This file is part of VRMLNETJ - The VRML net java server. VRMLNETJ is free software. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA For more information on the VRML net java server or Peter Graf, please see: http://www.mission-base.com/. $Log: vrmlnetj.java,v $ ------------------------------------------------------------------------------ */ //package vrmlnetj; import java.io.*; import java.net.*; import java.util.*; /** * A class containing scenes received */ public class Netjscene { /** * All scenes are kept in two static maps */ private static Map table; private static Map idTable; private static int nscenes; /** * All connections of the scene are kept in a map */ private Map connections; /** * The unique scene ID */ public String SCID; /** * The scene url, must be unique */ public String SCU; /** * The change ID of the scene, each attribute update increases this */ public int CHID; /** * The scene name, display name of the scene */ public String SCN; /** * All other attributes of the scene are kept in a map */ private Map attributeMap; /** * Time when the scene was created */ private long creationTime; private long lastEnter; private long lastLeft; /** * Count the connections for statistics */ public int nConnections; public long tConnections; /** * Create a new scene with a specific url */ public Netjscene( String sceneurl, String scenename ) { if( table == null ) { newTable(); } if( idTable == null ) { newTable(); } // set the creation time of the scene // creationTime = System.currentTimeMillis(); lastEnter = 0; lastLeft = 0; nConnections = 0; tConnections = 0; // initialize the change count // CHID = 0; // synchronize the creation access to the table // synchronized( table ) { // make sure the scene url is unique, add the scene to the table // SCU = new String( sceneurl ); if( table.containsKey( SCU )) { return; } table.put( SCU, this ); // count the scenes knowns // nscenes = table.size(); // create a unique scene id and add to id table // for(;;) { SCID = vrmlnetj.randstr(); if( idTable.containsKey( SCID )) { continue; } idTable.put( SCID, this ); break; } // remember the scene name // if( scenename != null ) { SCN = new String( scenename ); } else { SCN = new String( "" ); } vrmlnetj.log( "LOG", "NEW SCEN " + SCID + " SCU " + SCU + " SCN " + SCN ); // create the connection table of the scene // connections = new HashMap(); // create the attributes table of the scene // attributeMap = new HashMap(); } } /** * Set an attribute for a scene */ public void setAttribute( String k, String v ) { if( table == null ) { return; } // synchronize the access to the table // synchronized( table ) { // increase the change counter // CHID++; if( attributeMap == null ) { return; } if( attributeMap.containsKey( k )) { attributeMap.remove( k ); } attributeMap.put( k, v ); } //vrmlnetj.log( "TRA ", "SCNSET " + k + " TO " + v + " CHID " + CHID ); } /** * Get the change counter */ public String getChid( ) { return( vrmlnetj.hex8str( CHID )); } /** * Get an attribute of a scene */ public String getAttribute( String k ) { if( table == null ) { return( "" ); } // synchronize the access to the table // synchronized( table ) { if( attributeMap == null ) { return( "" ); } String res = (String)attributeMap.get( k ); if( res != null ) { res = new String( res ); } else { res = ""; } return( res ); } } /** * Find a scene by its scene url */ public static Netjscene find( String sceneurl, String scenename ) { if( table == null ) { return( null ); } // synchronize the access to the table // synchronized( table ) { Netjscene scene = (Netjscene)table.get( sceneurl ); // if the scene does not have a name yet we set it here // if( scene != null && scenename != null && scene.SCN.length() == 0 ) { scene.SCN = new String( scenename ); } return( scene ); } } /** * Find a scene by its scene id */ public static Netjscene find( String id ) { if( idTable == null || table == null ) { return( null ); } // synchronize the access to the table // synchronized( table ) { Netjscene scene = (Netjscene)idTable.get( id ); return( scene ); } } /** * Add a connection to a scene */ public void addConnection( Netjconn conn ) { if( connections == null ) { connections = new HashMap(); } // synchronize the access to the connections // synchronized( connections ) { CHID++; Netjconn c = (Netjconn)connections.get( conn.CID ); if( c != null ) { connections.remove( conn.CID ); } connections.put( conn.CID, conn ); // Count the connections // nConnections = connections.size(); tConnections++; lastEnter = System.currentTimeMillis(); } } /** * Delete a connection from a scene */ public int deleteConnection( Netjconn conn ) { if( connections == null ) { return( 0 ); } // synchronize the access to the connections // synchronized( connections ) { Netjconn c = (Netjconn)connections.get( conn.CID ); if( c != null ) { CHID++; // Count the connections // lastLeft = System.currentTimeMillis(); connections.remove( conn.CID ); nConnections = connections.size(); if( nConnections < 1 ) { vrmlnetj.log( "LOG", "DEL SCEN " + SCID + " SCU " + SCU + " SCN " + SCN ); if( table != null ) { // synchronize the access to the scenes // synchronized( table ) { table.remove( SCU ); idTable.remove( SCID ); } } } } } return( nConnections ); } /** * Send a packet to all connections in a scene */ public void send( Netjsendpacket packet, /** packet to send */ String exceptCID /** do not send to connection with this CID */ ) { if( connections == null ) { return; } // synchronize the access to the connections // synchronized( connections ) { Set s = connections.keySet(); for( Iterator i = s.iterator(); i.hasNext(); ) { String currkey = (String)i.next(); Netjconn conn = (Netjconn)connections.get( currkey ); if( exceptCID != null && exceptCID.equals( conn.CID )) { // do not send to this connection // continue; } // send the packet to this connection // packet.send( conn ); } } } /** * Send attribute packets about all connections in a scene */ public void sendConnectionAttributes( Netjconn conn /** connection to send packets to */ ) { if( connections == null ) { return; } // synchronize the access to the connections // synchronized( connections ) { Set s = connections.keySet(); for( Iterator i = s.iterator(); i.hasNext(); ) { String currkey = (String)i.next(); Netjconn current = (Netjconn)connections.get( currkey ); // ignore the current connection // if( conn.CID.equals( current.CID )) { continue; } // create and send a reply // Netjsendpacket reply = new Netjsendpacket( conn, "RQ" ); reply.setString( "SET" ); reply.setString( "CLID", current.CLID ); reply.setString( "CHID", current.getChid() ); int k; // loop through all attributes requested // for( k = 4; k < vrmlnetj.nstrargs; k++ ) { String arg = vrmlnetj.strargs[ k ]; if( reply.setString( arg, current.getAttribute( arg )) < 1 ) { break; } } if( k >= vrmlnetj.nstrargs ) { // send the reply to the client // reply.send(); } } } } /** * Send attribute packets about all scenes known */ public void sendSceneAttributes( Netjconn conn /** connection to send packets to */ ) { if( table == null || conn.scene == null ) { return; } // synchronize the access to the scenes // synchronized( table ) { Set s = table.keySet(); for( Iterator i = s.iterator(); i.hasNext(); ) { String currkey = (String)i.next(); Netjscene scene = (Netjscene)table.get( currkey ); // ignore the current connection // if( conn.scene.SCID.equals( scene.SCID )) { continue; } // prevent other threads from updating the scene // synchronized( scene.SCID ) { // create and send a reply // Netjsendpacket reply = new Netjsendpacket( conn, "RQ" ); reply.setString( "SET" ); reply.setString( "SCID", scene.SCID ); reply.setString( "CHID", scene.getChid() ); int k; // loop through all attributes requested // for( k = 4; k < vrmlnetj.nstrargs; k++ ) { String arg = vrmlnetj.strargs[ k ]; String val = null; if( arg.equals( "NPP" )) { val = "" + scene.nConnections; } else if( arg.equals( "NSN" )) { val = "" + scene.getNScenes(); } else if( arg.equals( "SCU" )) { val = scene.SCU; } else if( arg.equals( "SCN" )) { val = scene.SCN; } else { // get the attribute from the scene // val = scene.getAttribute( arg ); } if( reply.setString( arg, val ) < 1 ) { break; } } if( k >= vrmlnetj.nstrargs ) { // send the reply to the client // reply.send(); } } } } } /** * Periodic handling of the scenes, delete empty ones */ public static void periodic() { if( table == null ) { newTable(); } // synchronize the table access // synchronized( table ) { // run through all scenes that are active // Set s = table.keySet(); HashSet expired = new HashSet(); for( Iterator i = s.iterator(); i.hasNext(); ) { String currkey = (String)i.next(); Netjscene scene = (Netjscene)table.get( currkey ); if( scene.connections == null ) { // remove the attributes // scene.attributeMap = null; vrmlnetj.log( "LOG", "TOT SCEN " + scene.SCID + " SCU " + scene.SCU + " SCN " + scene.SCN ); expired.add( currkey ); idTable.remove( scene.SCID ); continue; } // synchronize on the connections // synchronized( scene.connections ) { scene.nConnections = scene.connections.size(); if( scene.nConnections < 1 ) { // remove the attributes // scene.attributeMap = null; vrmlnetj.log( "LOG", "TOT SCEN " + scene.SCID + " SCU " + scene.SCU + " SCN " + scene.SCN ); expired.add( currkey ); idTable.remove( scene.SCID ); } } } // delete expired elements from the table // for( Iterator i = expired.iterator(); i.hasNext(); ) { String currkey = (String)i.next(); table.remove( currkey ); } nscenes = table.size(); } } /** * Return the total number of scenes known on server */ public int getNScenes() { int res; if( table == null ) { return( 0 ); } // synchronize the table access // synchronized( table ) { res = nscenes; } return( res ); } /** * Create the scene tables, synchronized */ private synchronized static void newTable() { if( table == null ) { table = new HashMap(); nscenes = 0; } if( idTable == null ) { idTable = new HashMap(); } } }