core (xmpp, core_type): SatXMPPEntity can now handle plugin data:

2 new methods `get_plugin_data` and `set_plugin_data` let plugin register data for a given
profile session (i.e. client instance). This is the clean way to handle plugin data
(instead of the former way of adding custom attribute to `client` instance), and it uses
generics so type hints are working correctly with linters.

libervia/backend/core/core_types.py

@@ -18,7 +18,8 @@
 
 from abc import ABC, abstractmethod
 from collections import namedtuple
-from typing import TYPE_CHECKING, Any
+from dataclasses import dataclass
+from typing import TYPE_CHECKING, Any, Type, TypeVar
 from twisted.internet import defer
 from twisted.python import failure
 from typing_extensions import TypedDict
@@ -38,6 +39,9 @@ if TYPE_CHECKING:
     from txtorcon import Tor
 
 
+D = TypeVar("D")
+
+
 EncryptionPlugin = namedtuple(
     "EncryptionPlugin", ("instance", "name", "namespace", "priority", "directed")
 )
@@ -87,11 +91,40 @@ class SatXMPPEntity(ABC):
     xmlstream: xmlstream.XmlStream
     tor: "Tor | None" = None
 
+    def __init__(self) -> None:
+        self.plugin_data: dict[str, Any] = {}
+
     @property
     def tor_mode(self) -> "TorMode":
         """Return Tor mode for this profile."""
         raise NotImplementedError
 
+    def get_plugin_data(self, import_name: str, plugin_data_model: Type[D]) -> D:
+        """Retrieve data for a plugin.
+
+        Those data are per profile session (i.e. client instance).
+        If there is no data for this plugin in this instance, it will be created with not
+        arguments, which means that the model must have default value for every field.
+        If it's not the case, use "set_plugin_data" before the first call of
+        "get_plugin_data".
+        """
+        try:
+            data = self.plugin_data[import_name]
+        except KeyError:
+            data = self.plugin_data[import_name] = plugin_data_model()
+
+        return data
+
+    def set_plugin_data(self, import_name: str, plugin_data: object) -> None:
+        """Set plugin data.
+
+        This will store plugin data in current client instance.
+        """
+        if import_name in self.plugin_data:
+            raise exceptions.ConfigError("Plugin data already stored in {import_name!r}")
+        self.plugin_data[import_name] = plugin_data
+
+
     @property
     @abstractmethod
     def treq(self) -> "HTTPClient":

libervia/backend/core/xmpp.py

@@ -113,6 +113,7 @@ class SatXMPPEntity(core_types.SatXMPPEntity):
     profiles_connecting = set()
 
     def __init__(self, host_app, profile, max_retries):
+        core_types.SatXMPPEntity.__init__(self)
         factory = self.factory
 
         # we monkey patch clientConnectionLost to handle network_enabled/network_disabled