Websocket Queue

docs/docs/release_notes.md

@@ -1,3 +1,6 @@
+### 3.8.0
+- Handle WebSocket connections when we have multiple workers with `multiprocessing.Manager`
+
 ### 3.7.0
 - Add `ModelSerializer`
 

docs/docs/websocket.md

@@ -50,9 +50,15 @@ urls = {
         from panther.websocket import send_message_to_websocket
         await send_message_to_websocket(connection_id='7e82d57c9ec0478787b01916910a9f45', data='New Message From WS') 
         ```
-8. If you want to use `webscoket` in `multi-tread` or `multi-instance` backend, you should add `RedisMiddleware` in your `configs` or it won't work well.
+8. If you want to use `webscoket` in a backend with `multiple workers`, we recommend you to add `RedisMiddleware` in your `configs` 
 [[Adding Redis Middleware]](https://pantherpy.github.io/middlewares/#redis-middleware)
-9. If you want to close a connection:
+9. If you don't want to add `RedisMiddleware` and you still want to use `websocket` in `multi-thread`, 
+you have to use `--preload` option while running the project like below:
+   ```bash
+   gunicorn -w 10 -k uvicorn.workers.UvicornWorker main:app --preload
+   ```
+
+10. If you want to close a connection:
     - In websocket class scope: You can close connection with `self.close()` method which takes 2 args, `code` and `reason`:
         ```python
         from panther import status
@@ -65,7 +71,7 @@ urls = {
         await close_websocket_connection(connection_id='7e82d57c9ec0478787b01916910a9f45', code=status.WS_1008_POLICY_VIOLATION, reason='')
         ``` 
 
-10. `Path Variables` will be passed to `connect()`:
+11. `Path Variables` will be passed to `connect()`:
    ```python
     from panther.websocket import GenericWebsocket
 
@@ -77,6 +83,6 @@ urls = {
         '/ws/<user_id>/<room_id>/': UserWebsocket   
     }
    ``` 
-11. WebSocket Echo Example -> [Https://GitHub.com/PantherPy/echo_websocket](https://github.com/PantherPy/echo_websocket)
-12. Enjoy.
+12. WebSocket Echo Example -> [Https://GitHub.com/PantherPy/echo_websocket](https://github.com/PantherPy/echo_websocket)
+13. Enjoy.
 

example/model_serializer_example.py

@@ -1,6 +1,6 @@
 from pydantic import Field
 
-from panther import status, Panther
+from panther import Panther, status
 from panther.app import API
 from panther.db import Model
 from panther.request import Request

panther/__init__.py

@@ -1,6 +1,6 @@
 from panther.main import Panther  # noqa: F401
 
-__version__ = '3.7.0'
+__version__ = '3.8.0'
 
 
 def version():

panther/base_websocket.py

@@ -3,67 +3,106 @@
 import asyncio
 import contextlib
 import logging
-from typing import TYPE_CHECKING
+from multiprocessing import Manager
+from typing import TYPE_CHECKING, Literal
 
 import orjson as json
 
 from panther import status
 from panther._utils import generate_ws_connection_id
 from panther.base_request import BaseRequest
 from panther.configs import config
+from panther.db.connection import redis
 from panther.utils import Singleton
 
 if TYPE_CHECKING:
     from redis import Redis
 
-
 logger = logging.getLogger('panther')
 
 
+class PubSub:
+    def __init__(self, manager):
+        self._manager = manager
+        self._subscribers = self._manager.list()
+
+    def subscribe(self):
+        queue = self._manager.Queue()
+        self._subscribers.append(queue)
+        return queue
+
+    def publish(self, msg):
+        for queue in self._subscribers:
+            queue.put(msg)
+
+
 class WebsocketConnections(Singleton):
-    def __init__(self):
+    def __init__(self, manager: Manager = None):
         self.connections = {}
         self.connections_count = 0
+        self.manager = manager
 
     def __call__(self, r: Redis | None):
         if r:
             subscriber = r.pubsub()
             subscriber.subscribe('websocket_connections')
             logger.info("Subscribed to 'websocket_connections' channel")
             for channel_data in subscriber.listen():
-                # Check Type of PubSub Message
                 match channel_data['type']:
+                    # Subscribed
                     case 'subscribe':
                         continue
 
+                    # Message Received
                     case 'message':
                         loaded_data = json.loads(channel_data['data'].decode())
-                        if (
-                                isinstance(loaded_data, dict)
-                                and (connection_id := loaded_data.get('connection_id'))
-                                and (data := loaded_data.get('data'))
-                                and (action := loaded_data.get('action'))
-                                and (connection := self.connections.get(connection_id))
-                       ):
-                            # Check Action of WS
-                            match action:
-                                case 'send':
-                                    logger.debug(f'Sending Message to {connection_id}')
-                                    asyncio.run(connection.send(data=data))
-                                case 'close':
-                                    with contextlib.suppress(RuntimeError):
-                                        asyncio.run(connection.close(code=data['code'], reason=data['reason']))
-                                        # We are trying to disconnect the connection between a thread and a user
-                                        # from another thread, it's working, but we have to find another solution it
-                                        #
-                                        # Error:
-                                        # Task <Task pending coro=<Websocket.close()>> got Future
-                                        # <Task pending coro=<WebSocketCommonProtocol.transfer_data()>>
-                                        # attached to a different loop
-                                case _:
-                                    logger.debug(f'Unknown Message Action: {action}')
-                    case _:
-                        logger.debug(f'Unknown Channel Type: {channel_data["type"]}')
+                        self._handle_received_message(received_message=loaded_data)
+
+                    case unknown_type:
+                        logger.debug(f'Unknown Channel Type: {unknown_type}')
+        else:
+            self.pubsub = PubSub(manager=self.manager)
+            queue = self.pubsub.subscribe()
+            logger.info("Subscribed to 'websocket_connections' queue")
+            while True:
+                received_message = queue.get()
+                self._handle_received_message(received_message=received_message)
+
+    def _handle_received_message(self, received_message):
+        if (
+                isinstance(received_message, dict)
+                and (connection_id := received_message.get('connection_id'))
+                and connection_id in self.connections
+                and 'action' in received_message
+                and 'data' in received_message
+        ):
+            # Check Action of WS
+            match received_message['action']:
+                case 'send':
+                    asyncio.run(self.connections[connection_id].send(data=received_message['data']))
+                case 'close':
+                    with contextlib.suppress(RuntimeError):
+                        asyncio.run(self.connections[connection_id].close(
+                            code=received_message['data']['code'],
+                            reason=received_message['data']['reason']
+                        ))
+                        # We are trying to disconnect the connection between a thread and a user
+                        # from another thread, it's working, but we have to find another solution for it
+                        #
+                        # Error:
+                        # Task <Task pending coro=<Websocket.close()>> got Future
+                        # <Task pending coro=<WebSocketCommonProtocol.transfer_data()>>
+                        # attached to a different loop
+                case unknown_action:
+                    logger.debug(f'Unknown Message Action: {unknown_action}')
+
+    def publish(self, connection_id: str, action: Literal['send', 'close'], data: any):
+        publish_data = {'connection_id': connection_id, 'action': action, 'data': data}
+
+        if redis.is_connected:
+            redis.publish('websocket_connections', json.dumps(publish_data))
+        else:
+            self.pubsub.publish(publish_data)
 
     async def new_connection(self, connection: Websocket) -> None:
         await connection.connect(**connection.path_variables)
@@ -106,6 +145,7 @@ async def receive(self, data: str | bytes) -> None:
         pass
 
     async def send(self, data: any = None) -> None:
+        logger.debug(f'Sending WS Message to {self.connection_id}')
         if data:
             if isinstance(data, bytes):
                 await self.send_bytes(bytes_data=data)
@@ -121,6 +161,7 @@ async def send_bytes(self, bytes_data: bytes) -> None:
         await self.asgi_send({'type': 'websocket.send', 'bytes': bytes_data})
 
     async def close(self, code: int = status.WS_1000_NORMAL_CLOSURE, reason: str = '') -> None:
+        logger.debug(f'Closing WS Connection {self.connection_id}')
         self.is_connected = False
         config['websocket_connections'].remove_connection(self)
         await self.asgi_send({'type': 'websocket.close', 'code': code, 'reason': reason})

panther/main.py

@@ -5,6 +5,7 @@
 import types
 from collections.abc import Callable
 from logging.config import dictConfig
+from multiprocessing import Manager
 from pathlib import Path
 from threading import Thread
 
@@ -52,14 +53,6 @@ def __init__(self, name: str, configs=None, urls: dict | None = None, startup: C
         # Print Info
         print_info(config)
 
-        # Start Websocket Listener (Redis Required)
-        if config['has_ws']:
-            Thread(
-                target=config['websocket_connections'],
-                daemon=True,
-                args=(self.ws_redis_connection,),
-            ).start()
-
     def load_configs(self) -> None:
 
         # Check & Read The Configs File
@@ -98,8 +91,7 @@ def load_configs(self) -> None:
         self._create_ws_connections_instance()
 
     def _create_ws_connections_instance(self):
-        from panther.base_websocket import Websocket
-        from panther.websocket import WebsocketConnections
+        from panther.base_websocket import Websocket, WebsocketConnections
 
         # Check do we have ws endpoint
         for endpoint in config['flat_urls'].values():
@@ -111,7 +103,6 @@ def _create_ws_connections_instance(self):
 
         # Create websocket connections instance
         if config['has_ws']:
-            config['websocket_connections'] = WebsocketConnections()
             # Websocket Redis Connection
             for middleware in config['http_middlewares']:
                 if middleware.__class__.__name__ == 'RedisMiddleware':
@@ -120,6 +111,10 @@ def _create_ws_connections_instance(self):
             else:
                 self.ws_redis_connection = None
 
+            # Don't create Manager() if we are going to use Redis for PubSub
+            manager = None if self.ws_redis_connection else Manager()
+            config['websocket_connections'] = WebsocketConnections(manager=manager)
+
     async def __call__(self, scope: dict, receive: Callable, send: Callable) -> None:
         """
         1.
@@ -138,6 +133,7 @@ async def __call__(self, scope: dict, receive: Callable, send: Callable) -> None
         if scope['type'] == 'lifespan':
             message = await receive()
             if message["type"] == "lifespan.startup":
+                await self.handle_ws_listener()
                 await self.handle_startup()
             return
 
@@ -262,6 +258,15 @@ async def handle_http(self, scope: dict, receive: Callable, send: Callable) -> N
             body=response.body,
         )
 
+    async def handle_ws_listener(self):
+        # Start Websocket Listener (Redis/ Queue)
+        if config['has_ws']:
+            Thread(
+                target=config['websocket_connections'],
+                daemon=True,
+                args=(self.ws_redis_connection,),
+            ).start()
+
     async def handle_startup(self):
         if startup := config['startup'] or self._startup:
             if is_function_async(startup):
@@ -272,7 +277,13 @@ async def handle_startup(self):
     def handle_shutdown(self):
         if shutdown := config['shutdown'] or self._shutdown:
             if is_function_async(shutdown):
-                asyncio.run(shutdown())
+                try:
+                    asyncio.run(shutdown())
+                except ModuleNotFoundError:
+                    # Error: import of asyncio halted; None in sys.modules
+                    #   And as I figured it out, it only happens when we running with
+                    #   gunicorn and Uvicorn workers (-k uvicorn.workers.UvicornWorker)
+                    pass
             else:
                 shutdown()
 

panther/response.py

@@ -35,9 +35,10 @@ def body(self) -> bytes:
 
     @property
     def headers(self) -> dict:
+        content_length = 0 if self.body == b'null' else len(self.body)
         return {
             'content-type': self.content_type,
-            'content-length': len(self.body),
+            'content-length': content_length,
             'access-control-allow-origin': '*',
         } | (self._headers or {})
 

panther/serializer.py

@@ -3,31 +3,44 @@
 
 
 class ModelSerializer:
-    def __new__(cls, *args, **kwargs):
+    def __new__(cls, *args, model=None, **kwargs):
+        # Check `metaclass`
         if len(args) == 0:
-            msg = f"you should not inherit the 'ModelSerializer', you should use it as 'metaclass' -> {cls.__name__}"
+            address = f'{cls.__module__}.{cls.__name__}'
+            msg = f"you should not inherit the 'ModelSerializer', you should use it as 'metaclass' -> {address}"
             raise TypeError(msg)
+
         model_name = args[0]
-        if 'model' not in kwargs:
-            msg = f"'model' required while using 'ModelSerializer' metaclass -> {model_name}"
+        data = args[2]
+        address = f'{data["__module__"]}.{model_name}'
+
+        # Check `model`
+        if model is None:
+            msg = f"'model' required while using 'ModelSerializer' metaclass -> {address}"
             raise AttributeError(msg)
+        # Check `fields`
+        if 'fields' not in data:
+            msg = f"'fields' required while using 'ModelSerializer' metaclass. -> {address}"
+            raise AttributeError(msg) from None
 
-        model_fields = kwargs['model'].model_fields
+        model_fields = model.model_fields
         field_definitions = {}
-        if 'fields' not in args[2]:
-            msg = f"'fields' required while using 'ModelSerializer' metaclass. -> {model_name}"
-            raise AttributeError(msg) from None
-        for field_name in args[2]['fields']:
+
+        # Collect `fields`
+        for field_name in data['fields']:
             if field_name not in model_fields:
-                msg = f"'{field_name}' is not in '{kwargs['model'].__name__}' -> {model_name}"
+                msg = f"'{field_name}' is not in '{model.__name__}' -> {address}"
                 raise AttributeError(msg) from None
-
             field_definitions[field_name] = (model_fields[field_name].annotation, model_fields[field_name])
-        for required in args[2].get('required_fields', []):
+
+        # Change `required_fields
+        for required in data.get('required_fields', []):
             if required not in field_definitions:
-                msg = f"'{required}' is in 'required_fields' but not in 'fields' -> {model_name}"
+                msg = f"'{required}' is in 'required_fields' but not in 'fields' -> {address}"
                 raise AttributeError(msg) from None
             field_definitions[required][1].default = PydanticUndefined
+
+        # Create Model
         return create_model(
             __model_name=model_name,
             **field_definitions