feat: support to msgpack ext type

src/socketio/msgpack_packet.py

@@ -1,18 +1,56 @@
+import logging
 import msgpack
 from . import packet
 
+logger = logging.getLogger('socketio')
+
 
 class MsgPackPacket(packet.Packet):
     uses_binary_events = False
 
     def encode(self):
         """Encode the packet for transmission."""
-        return msgpack.dumps(self._to_dict())
+        return self._encode()
+
+    def _encode(self, **kwargs):
+        return _msgpack.dumps(self._to_dict(), **kwargs)
 
     def decode(self, encoded_packet):
         """Decode a transmitted package."""
-        decoded = msgpack.loads(encoded_packet)
+        return self._decode(encoded_packet)
+
+    def _decode(self, encoded_packet, **kwargs):
+        decoded = msgpack.loads(encoded_packet, **kwargs)
         self.packet_type = decoded['type']
         self.data = decoded.get('data')
         self.id = decoded.get('id')
         self.namespace = decoded['nsp']
+
+    @classmethod
+    def _configure(cls, *args, **kwargs):
+        dumps_default = kwargs.pop('dumps_default', None)
+        ext_hook = kwargs.pop('ext_hook', msgpack.ExtType)
+
+        if args:
+            logger.warning(
+                'Some positional arguments to MsgPackPacket.configure() are '
+                'not used: %s',
+                args,
+            )
+        if kwargs:
+            logger.warning(
+                'Some keyword arguments to MsgPackPacket.configure() are '
+                'not used: %s',
+                kwargs,
+            )
+
+        class ConfiguredMsgPackPacket(cls):
+            def _encode(self, **kwargs):
+                kwargs.setdefault('default', dumps_default)
+                return super()._encode(**kwargs)
+
+            def _decode(self, encoded_packet, **kwargs):
+                kwargs.setdefault('ext_hook', ext_hook)
+                return super()._decode(encoded_packet, **kwargs)
+
+        return ConfiguredMsgPackPacket

src/socketio/packet.py

@@ -1,11 +1,13 @@
 import functools
+import logging
 from engineio import json as _json
 
 (CONNECT, DISCONNECT, EVENT, ACK, CONNECT_ERROR, BINARY_EVENT, BINARY_ACK) = \
     (0, 1, 2, 3, 4, 5, 6)
 packet_names = ['CONNECT', 'DISCONNECT', 'EVENT', 'ACK', 'CONNECT_ERROR',
                 'BINARY_EVENT', 'BINARY_ACK']
 
+logger = logging.getLogger('socketio.packet')
 
 class Packet:
     """Socket.IO packet."""
@@ -21,6 +23,8 @@ class Packet:
 
     uses_binary_events = True
     json = _json
+    _configure_args = ((),())
+    _subclass_registry = {}
 
     def __init__(self, packet_type=EVENT, data=None, namespace=None, id=None,
                  binary=None, encoded_packet=None):
@@ -192,3 +196,29 @@ def _to_dict(self):
         if self.id is not None:
             d['id'] = self.id
         return d
+
+    @classmethod
+    def configure(cls, *args, **kwargs):
+        configure_args = (args, tuple(sorted(kwargs.items())))
+        try:
+            args_hash = hash(configure_args)
+        except TypeError:
+            logger.warning("Packet.configure() called with unhashable "
+                           "arguments; subclass caching will not work.")
+            args_hash = None
+
+        if args_hash in cls._subclass_registry:
+            logger.debug("Using cached Packet subclass for args %s, %s",
+                         args, kwargs)
+            return cls._subclass_registry[args_hash]
+        new = cls._configure(*args, **kwargs)
+        if args_hash is not None:
+            cls._subclass_registry[args_hash] = new
+            logger.debug("Caching Packet subclass for args %s, %s",
+                         args, kwargs)
+        return new
+
+    @classmethod
+    def _configure(cls, *args, **kwargs):
+        raise NotImplementedError('Packet._configure() must be implemented '
+                                  'by subclasses.')