1 files changed, 40 insertions, 15 deletions
diff --git a/server/socket.py b/server/socket.py
index bdf99bf..ae2068f 100644
--- a/server/socket.py
+++ b/server/socket.py
@@ -17,26 +17,51 @@ _sessions_to_socket = {}  # keyed by sid: what session is bound to what socket
 _transactions_to_socket = {}  # keyed by tid, used only when there is no sid available, so a request can be replied
 
 
+def handle_connect(data):
+    """The first packet is 'connect', providing the list of connected sessions to the peer (that's us)."""
+    pass
+
+
+def handle_unregister(data):
+    """When the client disconnects from the peer, but doesn't logout first,
+    leaving the possibility that it will reconnect in the same session,
+    possibly via other channel (nodejs instance)."""
+    pass
+
+
+# TODO: meta handlers implement system protocol to support horizontal scaling, implement them when it becomes relevant
+_meta_handlers = {
+    'connect': handle_connect,
+    'unregister': handle_unregister
+}
+
+
 def processIncomingPacket(receiving_socket, packet):
     logging.debug('Decoding JSON: {}'.format(packet))
     obj = json.loads(packet)
     req_type = obj.get('type')  # private (meta) requests have the 'type'
-    if req_type == 'connect':
-        return  # TODO: first packet is 'connect', providing the list of connected sessions to the peer
-
-    tid = obj.get('tid')  # transaction ID
-    if tid is None:
-        raise Exception('Transaction ID is missing from the request')
-    sid = obj.get('sid')  # session ID
-    _mapping_lock.acquire()
-    try:
-        if sid is None:
-            _transactions_to_socket[tid] = receiving_socket
+    if req_type is None:
+        # user protocol, internally map the request so response can be delivered correctly, and forward it to the higher layer
+        tid = obj.get('tid')  # transaction ID
+        if tid is None:
+            raise Exception('Transaction ID is missing from the request')
+        sid = obj.get('sid')  # session ID
+        _mapping_lock.acquire()
+        try:
+            if sid is None:
+                _transactions_to_socket[tid] = receiving_socket
+            else:
+                _sessions_to_socket[sid] = receiving_socket
+        finally:
+            _mapping_lock.release()
+        serve_request(obj)
+    else:
+        # system protocol, connection-specific meta data
+        handler = _meta_handlers.get(req_type)
+        if handler is None:
+            logging.error('Received an unknown meta packet: {}'.format(req_type))
         else:
-            _sessions_to_socket[sid] = receiving_socket
-    finally:
-        _mapping_lock.release()
-    serve_request(obj)
+            handler(obj)
 
 
 def sendPacket(tid, sid, json_obj):