Merge pull request #51 from camuschat/db-bugfix

Fix database transaction bugs

CHANGELOG.rst

@@ -1,3 +1,10 @@
+Version 0.3.2
+-------------
+
+Released 2021-05-16
+
+- Fix bugs around database transactions
+
 Version 0.3.1
 -------------
 

camus/message_handler.py

@@ -6,7 +6,7 @@
 
 from camus import db
 from camus.models import Client
-from camus.util import get_ice_servers
+from camus.util import commit_database, get_ice_servers
 
 
 class MessageHandler:
@@ -56,7 +56,7 @@ async def _process_inbox(self):
                 # Update seen & active timestamps for client and room
                 client = Client.query.filter_by(uuid=client_uuid).first()
                 client.seen = client.room.active = datetime.datetime.utcnow()
-                db.session.commit()
+                commit_database()
 
                 # Message intended for the server
                 if message.receiver == self._address:
@@ -72,7 +72,7 @@ async def _process_inbox(self):
                     self.send(message)
 
             except Exception as e:
-                print('Error processing inbox: {}'.format(e))
+                logging.exception('Error processing inbox')
 
     def _handle_local_message(self, message):
         """Handle a message according to its type."""
@@ -97,7 +97,7 @@ def _handle_local_message(self, message):
             username = message.data.get('username')
             if username:
                 client.name = username
-                db.session.commit()
+                commit_database()
 
             reply.type = 'room-info'
             reply.data = self._room_info(client.room)
@@ -123,17 +123,19 @@ def _handle_local_message(self, message):
         elif message.type == 'bye':
             logging.info('got bye')
 
-            # Delete client object from db
             client = Client.query.filter_by(uuid=message.sender).first()
+            room = client.room
+
+            # Delete client object from db
             db.session.delete(client)
-            db.session.commit()
+            commit_database()
 
             # Remove message queues associated with the client
             self.outbox.pop(client.uuid, None)
 
             # Broadcast updated room info to remaining clients
             reply.type = 'room-info'
-            reply.data = self._room_info(client.room)
+            reply.data = self._room_info(room)
             self.broadcast(client.room, reply)
             reply = None
 

camus/routes.py

@@ -8,6 +8,7 @@
 from camus import db, message_handler
 from camus.forms import CreateRoomForm, JoinRoomForm
 from camus.models import Client, Room
+from camus.util import commit_database
 
 bp = Blueprint('main', __name__)
 
@@ -33,7 +34,7 @@ async def index():
             if password:
                 room.set_password(password)
             db.session.add(room)
-            db.session.commit()
+            commit_database(reraise=True)
 
             return redirect('/room/{}'.format(room.slug), code=307)
         except sqlalchemy.exc.IntegrityError:
@@ -62,7 +63,7 @@ async def room(room_id):
     client = room.authenticate()
     if client:
         db.session.add(client)
-        db.session.commit()
+        commit_database(reraise=True)
         session['id'] = client.uuid
 
         return await render_template(
@@ -77,7 +78,7 @@ async def room(room_id):
         client = room.authenticate(password)
         if client:
             db.session.add(client)
-            db.session.commit()
+            commit_database(reraise=True)
             session['id'] = client.uuid
 
             return await render_template(

camus/static/package.json

@@ -1,6 +1,6 @@
 {
   "name": "camus-chat",
-  "version": "0.3.1",
+  "version": "0.3.2",
   "description": "Peer-to-peer video chat using WebRTC",
   "main": "index.js",
   "directories": {

camus/util.py

@@ -10,6 +10,7 @@
 from twilio.base.exceptions import TwilioException, TwilioRestException
 
 from quart import current_app
+from sqlalchemy.exc import SQLAlchemyError
 
 from camus import db
 from camus.models import Client, Room
@@ -34,13 +35,32 @@ async def _run(self):
             try:
                 await self._callback(**self._kwargs)
             except Exception as e:
-                logging.error(traceback.format_exc())
+                logging.exception(
+                    "Exception during excecution of LoopTimer callback function"
+                )
 
     def cancel(self):
         """Cancel the running task."""
         self._task.cancel()
 
 
+def commit_database(log_error=True, rollback=True, reraise=False):
+    try:
+        db.session.commit()
+        return True
+    except SQLAlchemyError:
+        if log_error:
+            logging.exception('Exception during database commit.')
+
+        if rollback:
+            db.session.rollback()
+
+        if reraise:
+            raise
+
+        return False
+
+
 async def ping_clients(message_handler):
     """Send a ping message to all clients which have not been seen recently
     enough.
@@ -65,7 +85,7 @@ async def reap_clients(message_handler):
         room = client.room
         message_handler.send_bye(client.uuid)
         db.session.delete(client)
-        db.session.commit()
+        commit_database()
         message_handler.broadcast_room_info(room)
 
 
@@ -78,7 +98,7 @@ async def reap_rooms():
 
     for room in rooms:
         db.session.delete(room)
-        db.session.commit()
+        commit_database()
 
 
 def get_ice_servers(username):

setup.py

@@ -2,7 +2,7 @@
 
 setup(
     name='camus-chat',
-    version='0.3.1',
+    version='0.3.2',
     description='Peer-to-peer video chat using WebRTC',
     long_description=open('README.rst').read(),
     long_description_content_type="text/x-rst; charset=UTF-8",

snap/snapcraft.yaml

@@ -1,6 +1,6 @@
 name: camus
 base: core20
-version: '0.3.1'
+version: '0.3.2'
 summary: Peer-to-peer group video chat using WebRTC.
 description: |
   Camus is a group video chat server that uses WebRTC for direct peer-to-peer