Merge branch 'master' of ssh://vo20.nl/home/git/repos/uva

telematica/ass1/async.py

@@ -4,6 +4,10 @@ import re
 import random
 from asyncbase import AsyncBase
 
+# Socket error "Resource temporarily unavailable": try again ;)
+EAGAIN = 11
+
+
 class ClientConnection(object, AsyncBase, asyncore.dispatcher):
 
     def __init__(self):
@@ -51,6 +55,29 @@ class ClientConnection(object, AsyncBase, asyncore.dispatcher):
         if 'connect' in self.event_list:
             self.event_list['connect'](self)
 
+    def handle_error(self):
+        if hasattr(self, 'main'):
+            import sys
+            t, v, tb = sys.exc_info()
+            tbinfo = []
+            while tb:
+                tbinfo.append((
+                    tb.tb_frame.f_code.co_filename,
+                    tb.tb_frame.f_code.co_name,
+                    str(tb.tb_lineno)
+                    ))
+                tb = tb.tb_next
+
+            file, function, line = tbinfo[-1]
+            info = ' '.join(['[%s|%s|%s]' % x for x in tbinfo])
+            self.debug_log('Exception raised in "%s" (%s line %s). Traceback:' \
+                    % (function, file, line))
+            self.debug_log(info)
+            self.main.display_info(str(v))
+            #self.main.execute('disconnect')
+            #self.main.display_info('Error raised due to a broken or refused'\
+            #        + ' connection')
+
     def handle_close(self):
         self.close()
 
@@ -61,7 +88,18 @@ class ClientConnection(object, AsyncBase, asyncore.dispatcher):
 
         # Receive a (multiline) message.
         while True:
+            try:
                 chunk = self.recv(1)
+            except socket.error, e:
+                # Suppress "Resource temporarily unavailable" exceptions.
+                if e.errno == EAGAIN:
+                    # Wait 5 ms
+                    import time
+                    time.sleep(0.005)
+                    continue
+                else:
+                    raise
+
             if not chunk:
                 raise RuntimeError('socket connection broken')
             if chunk in ['-','+']:
@@ -78,7 +116,7 @@ class ClientConnection(object, AsyncBase, asyncore.dispatcher):
             buf += chunk
 
         buf = buf[:-1]
-        self.debug_log('< %s' % buf)
+        self.debug_log('< %s' % buf.replace('\n','\\n').replace('\r','\\r'))
 
         # Invoke the proper callback function.
         if not self.verified:
@@ -112,7 +150,7 @@ class ClientConnection(object, AsyncBase, asyncore.dispatcher):
             if not self.authentification_sent:
                 self.send_queue.put('USER %s' % self.user)
                 self.authentification_sent = True
-            elif buf[1:9] == 'Username':
+            elif buf[0] == '+':
                 # TODO: handle 'username is taken'.
                 self.authenticated = True
                 if 'authenticated' in self.event_list:
@@ -145,5 +183,5 @@ class ClientConnection(object, AsyncBase, asyncore.dispatcher):
 
 if __name__ == '__main__':
     client = ClientConnection()
-    client.connect(('ow150.science.uva.nl', 16897))
+    client.connect(('localhost', 16897))
     client.init_loop()

telematica/ass1/base_bar.py

@@ -16,15 +16,15 @@ class BaseBar(object):
         self.color_pair = curses.color_pair(0)
         self._prefix = ''
 
-    def prefix(self, value=''):
-        if not value:
+    def prefix(self, value=None):
+        if value == None: # Note: an empty string can also be set.
             return self._prefix
         self._prefix = value
         self.display(self._msg)
 
     def display(self, msg):
         self._msg = msg
-        if self.prefix:
+        if self.prefix():
             msg = self.prefix() + ' ' + msg
         # Curses will raise a 'curses.error' when the last possible character is
         # written. This exception should therefore always be catched. The raised

telematica/ass1/cli.py

 import curses
 import sys
 import threading
+from time import sleep
 
 from async import ClientConnection
 from chat_window import ChatWindow
@@ -102,6 +103,8 @@ class CLI:
                 c = self.stdscr.getch()
                 if c != curses.ERR and self.command_bar.handle_input(c):
                     break
+                # wait 1 milliseconds
+                sleep(.001)
         except KeyboardInterrupt:
             self.execute('quit')
 
@@ -141,6 +144,7 @@ class CLI:
 
             # The chat connection is ran in a separate thread.
             self.connection_thread = threading.Thread()
+            self.connection_thread.daemon = True
             self.connection_thread.run = main.connection.init_loop
             self.connection_thread.start()
 
@@ -152,10 +156,13 @@ class CLI:
             and the 'Offline' message is set to the info bar.
             """
 
+            self.connection.close()
+            del self.connection_thread
             self.connection = None
             self.display_info('Offline. Type "/connect HOST" to connect' \
                     + ' to another chat server.')
-            self.debug_window.clear()
+            self.info_bar.prefix('')
+            self.refresh()
 
         def help(main):
             if main.chat_window.displayed_help:
@@ -204,13 +211,6 @@ All commands listed below should be preceded by a slash:
             main.chat_window.window.refresh()
 
         def quit(main):
-            # Disconnect the connection
-            e = None
-            try:
-                del self.connection
-            except Exception, e:
-                pass
-
             # Reverse the curses-friendly terminal settings.
             curses.nocbreak();
             self.stdscr.keypad(0);
@@ -219,9 +219,10 @@ All commands listed below should be preceded by a slash:
             # Restore the terminal to its original operating mode.
             curses.endwin()
 
-            if e:
-                raise e
-
+            # Disconnect the connection
+            if hasattr(self, 'connection_thread'):
+                del self.connection_thread
+            self.connection = None
             sys.exit(0)
 
         def raw(main, cmd):

telematica/ass1/server.py

@@ -4,16 +4,25 @@ import asyncore
 import logging
 import logging.config
 import os
+import re
 import socket
 import sys
 
 from asyncbase import AsyncBase
 
+# Greeting message sent to a connected client.
 GREETING_MSG = 'Hi there!'
 
+# Major and minor version of this server.
 MAJOR_VERSION = 1
 MINOR_VERSION = 0
 
+class SocketError(RuntimeError):
+    pass
+
+class ClientData(object):
+    pass
+
 class Server(asyncore.dispatcher):
     """
     Basic server which will listen on an host address and port. The given
@@ -27,18 +36,18 @@ class Server(asyncore.dispatcher):
         self.port = port
         self.handler = handler
 
-        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
-
-        self.set_reuse_addr()
-        self.bind((ip, port))
-
         logging.config.fileConfig('logging.conf')
         self.log = logging.getLogger('Server')
 
+        # Listen on given ip-address and port
+        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
+        self.set_reuse_addr()
+        self.bind((ip, port))
         self.log.info('waiting for incoming connections on port %s.' % port)
         self.listen(5)
 
-        self.active_clients = {}
+        # Dictonary which maps ip/port tuple to client data object.
+        self.clients = {}
 
     def handle_accept(self):
         """
@@ -48,53 +57,160 @@ class Server(asyncore.dispatcher):
         try:
             conn, addr = self.accept()
             self.log.info('accepted client %s:%d' % addr)
+            client = self.connect_client(conn, addr)
         except socket.error:
             self.log.warning('warning: server accept() threw an exception.')
             return
         except TypeError:
             self.log.warning('warning: server accept() threw EWOULDBLOCK.')
             return
+
+    def connect_client(self, conn, addr):
+        """
+        Initialise a client connection after the server accepted an incoming
+        connection. This will set the connection handler.
+        """
+        client = ClientData()
         # creates an instance of the handler class to handle the
         # request/response on the incoming connection.
-        self.handler(conn, addr, self)
+        client.handler = self.handler(conn, addr, client, self)
+        client.username = ''
+        self.clients['%s:%d' % addr] = client
+        return client
+
+    def disconnect_client(self, addr):
+        """
+        Client leaves the chat server. This function is called when the socket
+        is broken or the client closes the connection gracefully.
+        """
+        # Suppress error if a client is already disconnected.
+        try:
+            client = self.clients['%s:%d' % addr]
+            self.send_all('LEAVE %s' % client.username, True)
+            del self.clients['%s:%d' % addr]
+        except KeyError:
+            pass
+
+    def change_username(self, addr, username):
+        """
+        Update the username of the client.
+        """
+        self.clients['%s:%d' % addr].username = username
+
+    def send_all(self, msg, sender=None):
+        """
+        Send a message or notification from a client to all connected clients
+        (optionally including to the sender).
+        """
+        for c in self.clients:
+            if self.clients[c].handler != sender:
+                self.clients[c].handler.send_raw(msg)
 
 class RequestHandler(AsyncBase, asyncore.dispatcher):
-    def __init__(self, conn, address, server):
+    def __init__(self, conn, address, client, server):
         AsyncBase.__init__(self)
         asyncore.dispatcher.__init__(self, conn)
 
         self.address = address
+        self.client = client
         self.server = server
+        self.username = ''
 
         self.log = self.server.log
         self.send_welcome_message()
 
     def send_welcome_message(self):
+        """
+        Welcome our new client by sending a welcome message. This message
+        contains the server version number and a greetings message.
+        """
         self.send_raw("CHAT/%d.%d/%s" \
                 % (MAJOR_VERSION, MINOR_VERSION, GREETING_MSG))
 
     def handle_read(self):
+        """
+        Receive a message from the client. If the connection is somehow broken,
+        disconnect the client and clean the corresponding data.
+        """
         buf = ''
-        # Receive a message from the client.
+        try:
             while True:
                 chunk = self.recv(1)
                 if not chunk:
-                raise RuntimeError('socket connection broken')
+                    raise SocketError('socket connection broken')
                 elif chunk == '\n' and buf[-1] == '\r':
                     break
                 buf += chunk
+        except SocketError, socket.error:
+            self.log.info('client %s:%d disconnected or socket is broken.' \
+                    % self.address)
+            self.server.disconnect_client(self.address)
+            return
 
+        # Received a message, so it's time to parse the message.
         buf = buf[:-1]
         self.debug_log('< %s' % buf)
+        self.parse_response(buf)
+
+    def handle_error(self):
+        self.server.disconnect_client(self.address)
 
-        self.send_positive('Ok')
-        #self.send_negative('Ok')
+    def parse_response(self, buf):
+        """
+        >>> class DummyServer(object):
+        ...     def __init__(self): self.log = None
+        ...     def change_username(self, addr, username): pass
+        ...     def send_all(self, msg, sender): pass
+        >>> req = RequestHandler(None, None, None, DummyServer())
+        >>> assert req.parse_response('CHAT')
+        >>> assert req.parse_response('USER foo')
+        >>> # Some error handling
+        >>> assert not req.parse_response('CHAT ')    # Client must send CHAT
+        >>> assert not req.parse_response('USER')     # No username given.
+        >>> assert not req.parse_response('USER j/k') # username has a /
+        """
+        cmd = buf.split(' ')[0]
+
+        if buf == 'CHAT':
+            # Client wants to chat.
+            return self.send_positive('Ok')
+        if cmd == 'USER':
+            # User changes/sets its username.
+            if re.match(ur'^[^\u0000-\u001f\u007f-\u009f/:]+$', buf[5:]):
+                if not self.username:
+                    self.send_all('JOIN %s' % buf[5:], True)
+                else:
+                    self.send_all('RENAME %s/%s' \
+                            % (self.username, buf[5:]), True)
+                self.set_username(buf[5:])
+                return self.send_positive('Ok')
+            return self.send_negative('Invalid username.')
+
+        # TODO: user can't send a message if he didn't send his username first.
+        if cmd == 'SAY':
+            return self.send_all('SAY %s/%s' % (self.username, buf[4:]))
+        if cmd == 'NAMES':
+            clients = self.server.clients
+            self.send_raw('+Ok:\r\n' \
+                    + ''.join([clients[c].username + '\r\n' for c in clients]))
+            return True
+        return self.send_negative('Unsupported command.')
 
     def send_positive(self, msg):
         self.send_raw('+%s' % msg)
+        return True
 
     def send_negative(self, msg):
         self.send_raw('-%s' % msg)
+        return False
+
+    def send_all(self, msg, except_sender=False):
+        self.server.send_all(msg, except_sender and self)
+        return True
+
+    def set_username(self, username):
+        self.username = username
+        self.server.change_username(self.address, username)
 
 if __name__ == '__main__':
     if len(sys.argv) != 3: