Added the Nexus II source code files.

1 files changed, 280 insertions, 0 deletions

diff --git a/java/apps/NexusII/src/NexusIIserver.java b/java/apps/NexusII/src/NexusIIserver.java
new file mode 100644
index 00000000000..e3b5a52acd5
--- /dev/null
+++ b/java/apps/NexusII/src/NexusIIserver.java
@@ -0,0 +1,280 @@
+// The Nexus II server.
+// Sumedh Mungee <sumedh@cs.wustl.edu>
+
+import java.net.*;
+import java.io.*;
+import java.util.*;
+import ACE.OS.*;
+import ACE.SOCK_SAP.*;
+
+public class NexusIIserver implements consts {
+
+  // Entry point into the server
+  public static void main(String args[]) throws IOException {
+    
+    if(args.length != 1) {
+      System.out.println("Usage: java NexusIIserver <port_num>");
+      return;
+    }
+
+    // Create a "Hotel", which is a factory to generate Rooms
+    // as and when required.
+    RoomFactory Hotel = new RoomFactory();
+
+    System.out.println("NexusII server booting");
+    SOCKAcceptor sacceptor = new SOCKAcceptor( (new Integer(args[0])).intValue());
+
+    System.out.println("NexusII is now accepting connections on port " + (new Integer(args[0])).intValue());
+    
+    for(;;) { 
+      
+      SOCKStream s = new SOCKStream();
+      sacceptor.accept(s);
+      // Accepted connection
+      // construct a client handler..
+      // Pass in the connected socket as an argument,
+      // and a reference to the Hotel, in case it needs
+      // to create rooms..
+      // and away you go..
+      new Thread(new ClientHandler(s, Hotel)).start();
+      
+    }
+  }
+}  
+
+
+// This thread handles the clients..
+// It uses 2 additional threads for read/write network operations 
+// These threads are dedicated to read/write from the
+// respective read/write queues.. 
+class ClientHandler implements Runnable,consts {
+  
+  private SOCKStream s_;
+  private RoomFactory Hotel_;
+  private MT_Bounded_Queue rq_ = new MT_Bounded_Queue(QUEUE_SIZE);
+  private MT_Bounded_Queue wq_ = new MT_Bounded_Queue(QUEUE_SIZE);
+  private String my_name_;
+  private Vector roomlist_ = new Vector();
+  private boolean finished_ = false;
+  private String init_image_;
+  
+  public ClientHandler(SOCKStream s, RoomFactory h) {
+    s_ = s;
+    Hotel_ = h;
+    init_image_ = new String(System.getProperty("mywebaddress") + NEXUS_LOGO);
+  }
+  
+  public void run()  {
+      // Construct the reader/writer threads with the queues and the
+      // corresponding socket data streams as parameters.
+      Thread r_ = new socketReaderThread(rq_, new DataInputStream(s_.inputStream()));
+      Thread w_ = new socketWriterThread(wq_, new DataOutputStream(s_.outputStream()));
+      r_.start();
+      w_.start(); 
+      
+      // now start parsing the messages, and take action..
+      // todo: optimize the below..
+
+      while(!finished_) {
+	dataPacket d = (dataPacket) rq_.dq();
+	if(d.contentType().startsWith("INIT"))
+	  nexus_init(d);
+	if(d.contentType().startsWith("JOIN"))
+	  nexus_join(d);
+	if(d.contentType().startsWith("LEAVE"))
+	  nexus_leave(d);
+	if(d.contentType().startsWith("QUIT"))
+	  nexus_quit(d);
+	if(d.contentType().startsWith("TEXT"))
+	  nexus_text(d);
+	if(d.contentType().startsWith("LUSERS"))
+	  nexus_lusers(d);
+	if(d.contentType().startsWith("LROOMS"))
+	  nexus_lrooms(d);
+	if(d.contentType().startsWith("NICK"))
+	  nexus_nick(d);
+	if(d.contentType().startsWith("URL"))
+	  nexus_url(d);
+      }
+  }
+  
+  // The following classes implement the server functions..
+  
+  private void nexus_init(dataPacket packet) {
+    my_name_ = new String(packet.clientName());
+    wq_.nq(packet);
+  }
+
+  private void nexus_join(dataPacket packet) {
+    Room r = Hotel_.getRoom(packet.content());
+    if(r.checkClient(this)) 
+      return;
+    r.addClient(this);
+    roomlist_.addElement(r);
+    writeRoom(r, my_name_ + " has joined the room ");
+    String contenttype = new String("url");
+    dataPacket d = new dataPacket(my_name_, packet.content(), contenttype, (new Integer(init_image_.length())).toString() , init_image_);
+    wq_.nq(d);
+  }
+
+  private void nexus_text(dataPacket packet) {
+    Room r = Hotel_.getRoom(packet.destination());
+    r.getQ().nq(packet);
+  }
+  
+  private void nexus_lusers(dataPacket packet) {
+
+    Room r = Hotel_.getRoom(packet.content());
+    Enumeration e = r.clientList();
+    StringBuffer sb = new StringBuffer();
+    while(e.hasMoreElements()) 
+      sb.append(" " + ((ClientHandler)e.nextElement()).getName() + " ");
+    dataPacket d = new dataPacket(my_name_, packet.destination(), packet.contentType(), (new Integer(sb.length())).toString(), sb.toString());
+    wq_.nq(d);
+  }
+  
+  private void nexus_lrooms(dataPacket packet) {
+    String s = Hotel_.listRooms();
+    dataPacket d = new dataPacket(my_name_, packet.destination(), packet.contentType(), (new Integer(s.length())).toString(), s.toString());
+    wq_.nq(d);
+  }
+    
+  private void nexus_nick(dataPacket packet) {
+    Enumeration e = roomlist_.elements();
+    while(e.hasMoreElements()) 
+      writeRoom((Room)e.nextElement(), my_name_ + " is now known as " + packet.content());
+
+    my_name_ = new String(packet.content());
+  }
+
+  private void nexus_leave(dataPacket packet) {
+    
+    Room r = Hotel_.getRoom(packet.content());
+    writeRoom(r, my_name_ + " has left the room " + packet.content());
+    if(r.delClient(this)) Hotel_.delRoom(r);
+    roomlist_.removeElement(r);
+  }      
+  
+  private void nexus_quit(dataPacket packet) {
+    
+    Enumeration e = roomlist_.elements();
+    while(e.hasMoreElements()) {
+      Room r = (Room)e.nextElement();
+      writeRoom(r, my_name_ + " has quit " );
+      r.delClient(this);
+    }
+    finished_ = true;
+  }
+
+  private void nexus_url(dataPacket packet) {
+    try {
+      URL u = new URL(packet.content());
+
+      // first extract the filename stripped of its path.
+      int index = u.getFile().lastIndexOf("/");
+      String infilename = u.getFile().substring(index + 1);
+
+      // next construct the name of the temporary file
+      String outfilename = (System.getProperty("mywebdir") + "_" + packet.destination() + "." + infilename);
+
+      // now the temporary URL assigned to this request
+      String imageURL = new String(System.getProperty("mywebaddress") + "_" + packet.destination() + "." + infilename);
+
+      // Open temporary file for writing
+      FileOutputStream fout = new FileOutputStream(outfilename);
+
+      // Now contact alien ship
+      InputStream i = u.openStream();
+      byte[] buffer = new byte[1024];
+      
+      // And download the image
+      for(;;) {
+	int num = i.read(buffer);
+	if(num < 0) 
+	  break;
+	fout.write(buffer, 0, num);
+      }
+
+      fout.close();
+      i.close();
+      
+      // Get room for which this request was issued
+      Room r = Hotel_.getRoom(packet.destination());
+      
+      // invalidate previous entry
+      File f = new File(r.getLastImageName());
+      if(f.exists()) f.delete();
+
+      // add new image name
+      r.putNextImageName(outfilename);
+      writeRoom(r,"Asynchronously transferring image " + packet.content() + " from " + my_name_ );
+      dataPacket d = new dataPacket(my_name_, packet.destination(), packet.contentType(), (new Integer(imageURL.length())).toString(), imageURL);
+      r.getQ().nq(d); // multicast this imageURL onto the room..
+    
+    }
+    catch(java.net.MalformedURLException ue) {
+      System.out.println("warning:Invalid URL requested");
+    }
+    catch(java.io.IOException e) {
+      System.out.println("warning: IOException occurred");
+    }
+    
+  }
+
+  // Sends a "system" message msg onto room r
+  private void writeRoom(Room r, String msg) {
+    StringBuffer sb = new StringBuffer();
+    sb.append("==>");
+    sb.append(msg);
+    dataPacket d = new dataPacket(my_name_, r.getName() , "TEXT" , (new Integer(sb.length())).toString(), sb.toString());
+    r.getQ().nq(d);
+  }
+
+  public String getName() {
+    return my_name_;
+  }
+
+  public MT_Bounded_Queue getQ() {
+    return wq_;
+  }
+  
+}
+// ----------------------------------------------------------------------
+/** This class implements a room factory. getRoom returns an existing room,
+  or else creates it and returns a reference to a new room.
+  
+**/ 
+class RoomFactory implements consts {
+
+  private Vector Hotel_; 
+  public RoomFactory() { 
+    Hotel_ = new Vector(); 
+  } 
+  public synchronized Room getRoom(String name) {
+    Enumeration e = Hotel_.elements();
+    while(e.hasMoreElements()) {
+      Room r = (Room) e.nextElement();
+      if(r.getName().equals(name)) 
+ 	return r;
+    }
+    addRoom(name);
+    return getRoom(name);
+  } 
+  
+  private synchronized void addRoom(String name) {
+    Room r = new Room(name);
+    Hotel_.addElement(r);
+  }
+  public synchronized void delRoom(Room r) {
+    Hotel_.removeElement(r);
+  }
+  public synchronized String listRooms() {
+    Enumeration e = Hotel_.elements();
+    StringBuffer sb = new StringBuffer();
+    while(e.hasMoreElements())
+      sb.append(" " + ((Room)e.nextElement()).getName() + " ");
+    return sb.toString();
+  }
+}  
+
+