Telematica: report is finished.

telematica/ass1/doc/assignment.rst

@@ -46,3 +46,15 @@ text-based user interface of the client.
 .. [3] curses -- Terminal handling for character-cell displays:
    http://docs.python.org/library/curses.html.
 
+Protocol specification
+----------------------
+
+The instructions of this assignment required that the client and server should
+communication according to a given protocol. The protocol [4]_ is not further
+discussed in this report, since the protocol is described clearly and it would
+be redundant to add it to the report.
+
+.. [4] Client / server protocol:
+    http://staff.science.uva.nl/~mlankamp/2011/Telematica/protocol.desc
+
+

telematica/ass1/doc/implementation.rst

@@ -198,11 +198,23 @@ We implemented the following commands:
 Server side
 ----------
 
-Multiple client handling
-~~~~~~~~~~~~~~~~~~~~~~~~
-
 The class *Server* accepts the incoming connections from clients and initialises
 a request handler (see class *RequestHandler*) for each accepted connection. The
 servers logs all its information, warnings and errors to stdout. To change the
 behaviour of the server log, alter the configuration file *logging.conf*.
 
+In order to create a list of currently active users, we used an dictionary based
+on the client's address tuple (ip address, port). To check if a user does not
+take the nickname of an existing user, we simply iterate over the list of active
+users and compare the name of each user with the requested nickname. If it
+exists, return a negative response, otherwise if the nickname is valid according
+to the protocol, return a positive response. It is possible to build an index
+for the name lookup, but that optimization is not worth it as long as there
+aren't many clients connected. And if there are many clients connected, there
+are more important scalability problems to solve (e.g. better socket
+multiplexing, synchronisation between different server and load balancing).
+
+Compared to the client (and its interface), the server is very simplistic. This
+is on purpose, because we wanted to create a server which does exactly what is
+required in the protocol specification. In this case, less is more.
+

telematica/ass1/server.py

@@ -190,8 +190,7 @@ class RequestHandler(AsyncBase, asyncore.dispatcher):
             # already taken. If the name is valid, notify the other clients.
             name = buf[5:]
             for c in self.server.clients:
-                if self.server.clients[c].username == name \
-                        and self.server.clients[c].handler != self:
+                if self.server.clients[c].username == name:
                     return self.send_negative('Username already taken.')
             if re.match(ur'^[^\u0000-\u001f\u007f-\u009f/:]+$', name):
                 if not self.username: