Reworked session handling.

 * All requests have a session ID, except for the initial create_session system messages.
 * User session can be in an authenticated or anonymous state.
 * In anonymous state it is not possible to perform user actions.
 * Logout has been implemented.
 * Sessions timeout and are cleared after a period of inactivity (1 hour).
 * Bugfixed the lang setting handling.
 * Renamed get_problem -> get_current_solution, return only the user's current solution, not the whole problem data.

1 files changed, 3 insertions, 4 deletions

diff --git a/server/socket.py b/server/socket.py
index ae2068f..561ab29 100644
--- a/server/socket.py
+++ b/server/socket.py
@@ -206,13 +206,12 @@ class JsonClientSocket(SocketHandler):
             # TODO: unregister from any internal mechanisms
 
     def send(self, json_obj):
-        js = json.dumps(json_obj)
-        m = str(len(js)) + u':' + js
-        bytes = m.encode('utf-8')
+        b = json.dumps(json_obj).encode('utf-8')
+        b = bytes(str(len(b)), 'utf-8') + b':' + b
         lock = self._write_lock
         lock.acquire()
         try:
-            self.socket.sendall(bytes)
+            self.socket.sendall(b)
         finally:
             lock.release()